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Sample records for stable factorization approach

  1. Kadison-Kastler stable factors

    DEFF Research Database (Denmark)

    Cameron, Jan; Christensen, Erik; Sinclair, Allan M.

    2014-01-01

    It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition.......It is proven that a pair of continuous finite von Neumann algebra factors are unitarily equivalent if sufficiently close and one satisfies a certain cohomological condition....

  2. Local Search Approaches in Stable Matching Problems

    Directory of Open Access Journals (Sweden)

    Toby Walsh

    2013-10-01

    Full Text Available The stable marriage (SM problem has a wide variety of practical applications, ranging from matching resident doctors to hospitals, to matching students to schools or, more generally, to any two-sided market. In the classical formulation, n men and n women express their preferences (via a strict total order over the members of the other sex. Solving an SM problem means finding a stable marriage where stability is an envy-free notion: no man and woman who are not married to each other would both prefer each other to their partners or to being single. We consider both the classical stable marriage problem and one of its useful variations (denoted SMTI (Stable Marriage with Ties and Incomplete lists where the men and women express their preferences in the form of an incomplete preference list with ties over a subset of the members of the other sex. Matchings are permitted only with people who appear in these preference lists, and we try to find a stable matching that marries as many people as possible. Whilst the SM problem is polynomial to solve, the SMTI problem is NP-hard. We propose to tackle both problems via a local search approach, which exploits properties of the problems to reduce the size of the neighborhood and to make local moves efficiently. We empirically evaluate our algorithm for SM problems by measuring its runtime behavior and its ability to sample the lattice of all possible stable marriages. We evaluate our algorithm for SMTI problems in terms of both its runtime behavior and its ability to find a maximum cardinality stable marriage. Experimental results suggest that for SM problems, the number of steps of our algorithm grows only as O(n log(n, and that it samples very well the set of all stable marriages. It is thus a fair and efficient approach to generate stable marriages. Furthermore, our approach for SMTI problems is able to solve large problems, quickly returning stable matchings of large and often optimal size, despite the

  3. Stable Fly, (L., Dispersal and Governing Factors

    Directory of Open Access Journals (Sweden)

    Allan T. Showler

    2015-01-01

    Full Text Available Although the movement of stable fly, Stomoxys calcitrans (L., has been studied, its extent and significance has been uncertain. On a local scale (13 km is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one “lineage”, the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  4. An Efficient Approach for Identifying Stable Lobes with Discretization Method

    Directory of Open Access Journals (Sweden)

    Baohai Wu

    2013-01-01

    Full Text Available This paper presents a new approach for quick identification of chatter stability lobes with discretization method. Firstly, three different kinds of stability regions are defined: absolute stable region, valid region, and invalid region. Secondly, while identifying the chatter stability lobes, three different regions within the chatter stability lobes are identified with relatively large time intervals. Thirdly, stability boundary within the valid regions is finely calculated to get exact chatter stability lobes. The proposed method only needs to test a small portion of spindle speed and cutting depth set; about 89% computation time is savedcompared with full discretization method. It spends only about10 minutes to get exact chatter stability lobes. Since, based on discretization method, the proposed method can be used for different immersion cutting including low immersion cutting process, the proposed method can be directly implemented in the workshop to promote machining parameters selection efficiency.

  5. Stable Numerical Approach for Fractional Delay Differential Equations

    Science.gov (United States)

    Singh, Harendra; Pandey, Rajesh K.; Baleanu, D.

    2017-12-01

    In this paper, we present a new stable numerical approach based on the operational matrix of integration of Jacobi polynomials for solving fractional delay differential equations (FDDEs). The operational matrix approach converts the FDDE into a system of linear equations, and hence the numerical solution is obtained by solving the linear system. The error analysis of the proposed method is also established. Further, a comparative study of the approximate solutions is provided for the test examples of the FDDE by varying the values of the parameters in the Jacobi polynomials. As in special case, the Jacobi polynomials reduce to the well-known polynomials such as (1) Legendre polynomial, (2) Chebyshev polynomial of second kind, (3) Chebyshev polynomial of third and (4) Chebyshev polynomial of fourth kind respectively. Maximum absolute error and root mean square error are calculated for the illustrated examples and presented in form of tables for the comparison purpose. Numerical stability of the presented method with respect to all four kind of polynomials are discussed. Further, the obtained numerical results are compared with some known methods from the literature and it is observed that obtained results from the proposed method is better than these methods.

  6. Stable Numerical Approach for Fractional Delay Differential Equations

    International Nuclear Information System (INIS)

    Singh, Harendra; Pandey, Rajesh K.; Baleanu, D.

    2017-01-01

    In this paper, we present a new stable numerical approach based on the operational matrix of integration of Jacobi polynomials for solving fractional delay differential equations (FDDEs). The operational matrix approach converts the FDDE into a system of linear equations, and hence the numerical solution is obtained by solving the linear system. The error analysis of the proposed method is also established. Further, a comparative study of the approximate solutions is provided for the test examples of the FDDE by varying the values of the parameters in the Jacobi polynomials. As in special case, the Jacobi polynomials reduce to the well-known polynomials such as (1) Legendre polynomial, (2) Chebyshev polynomial of second kind, (3) Chebyshev polynomial of third and (4) Chebyshev polynomial of fourth kind respectively. Maximum absolute error and root mean square error are calculated for the illustrated examples and presented in form of tables for the comparison purpose. Numerical stability of the presented method with respect to all four kind of polynomials are discussed. Further, the obtained numerical results are compared with some known methods from the literature and it is observed that obtained results from the proposed method is better than these methods. (author)

  7. A parallel approach to the stable marriage problem

    DEFF Research Database (Denmark)

    Larsen, Jesper

    1997-01-01

    This paper describes two parallel algorithms for the stable marriage problem implemented on a MIMD parallel computer. The algorithms are tested against sequential algorithms on randomly generated and worst-case instances. The results clearly show that the combination fo a very simple problem...... and a commercial MIMD system results in parallel algorithms which are not competitive with sequential algorithms wrt. practical performance. 1 Introduction In 1962 the Stable Marriage Problem was....

  8. A balanced approach to the management of patients with stable ...

    African Journals Online (AJOL)

    2009-02-23

    Feb 23, 2009 ... The issue of the optimal management of patients with chronic stable coronary disease remains unsettled. There are strongly held views, and much emotive language is used in discussion. Not all opinions are entirely objective and practitioners' self-interest is all too often a powerful driver of the discussion.

  9. Stable Fly, Stomoxys calcitrans (L.), Dispersal and Governing Factors.

    Science.gov (United States)

    Showler, Allan T; Osbrink, Weste L A

    2015-01-01

    Although the movement of stable fly, Stomoxys calcitrans (L.), has been studied, its extent and significance has been uncertain. On a local scale (fly movement occurs between host animals and resting sites to feed and mate, mainly at on-farm locations where herbivorous livestock regularly congregate. Small numbers emigrate from livestock congregation sites in search of other hosts and oviposition substrate, mostly within stable flies are active year-round in warm latitudes, cold winters in temperate areas result in substantial population and activity declines, limiting movement of any sort to warmer seasons. Long-distance dispersal (>13 km) is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one "lineage", the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  10. Trophic position of coexisting krill species: a stable isotope approach

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard; Bode, Antonio; Nielsen, Torkel Gissel

    2014-01-01

    .2) indicating carnivory, while T. inermis (TP = 2.4 ± 0.3) had a more omnivorous diet. In turn, T. longicaudata and T. raschii (TP = 2.2 ± 0.2) were herbivorous. Along the fjord, nutrient and plankton composition affected trophic position. Thysanoessa longicaudata was more omnivorous offshore than inshore where......Four krill species with overlapping functional biology coexist in Greenland waters. Here, we used stable isotopes to investigate and discuss their trophic role and mode of coexistence. Bulk carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of Thysanoessa longicaudata, T. inermis, T. raschii...... and Meganyctiphanes norvegica sampled in June 2010 in the Godthåbsfjord, SW Greenland revealed new insight into their trophic roles and positions. There was a general positive correlation between body length and trophic position. The largest species M. norvegica had the highest trophic position (TP = 2.8 ± 0...

  11. Biological factors of natural and artificial ecosystems stable (unstable) functioning

    Science.gov (United States)

    Pechurkin, Nikolai S.

    The problem of sustainable development of humanity on Earth and the problem of supporting human life in space have the same scientific and methodological bases. The key to solve both problems is a long term maintenance of balanced material cycle. As a whole, natural or artificial ecosystems are to be more closed than open, but their elements (links of systems) are to be substantially open in interactions with each other. Prolonged stable interactions of different links have to have unique joint results - closed material cycling or biotic turnover. It is necessary to include, at least, three types of main links into any system to support real material cycling: producers, consumers, reducers. Producer links are now under studies in many laboratories. It is evident that the higher productivity of link, the lower link stability. Especially, it concerns with parasite impact to plants. As usual, artificial ecosystems are more simple (incomplete) than natural ecosystems, sometimes, they have not enough links for prolonged stable functioning. For example, life support system for space flight can be incomplete in consumer link, having only some crew persons, instead of interacting populations of consumers. As for reducer link, it is necessary to "organize" a special coordinated work of microbial biocenoses to fulfill proper cycling. Possible evolution of links, their self development is a matter of special attention for the maintenance of prolonged stable functioning. It's the most danger for systems with populations of quickly reproducing, so-called, R - strategists, according to symbols of logistic equation. From another side, quick reproduction of R - strategists is able to increase artificial ecosystems and their links functioning. After some damages of system, R - strategist's link can be quickly "self repaired" up to level of normal functioning. Some experimental data of this kind and mathematical models are to be discussed in the paper. This work is supported by

  12. A stable isotope approach for the quantification of sewer infiltration.

    Science.gov (United States)

    Kracht, Oliver; Gresch, Markus; Gujert, Willi

    2007-08-15

    Extraneous flows in wastewater collection systems are conventionally evaluated solely on the consideration of discharge hydrographs, which often involves a great degree of subjectivity and oversimplification. To obtain reliable information on the material fluxes within the urban environment, the use of intrinsic tracers can be the optimal choice. We demonstrate the successful use of naturally occurring stable isotopes of water (18O/16O and D/H) to accurately quantify extraneous discharge of groundwater in a combined sewer network. Fresh water supply from a distant hydrological regime provided usable isotopic separations between drinking water (proxy for real foul sewage) and local groundwater (proxy for sewer infiltration) of 1.8 per thousand in delta18O and 11.7 per thousand in 62H. Diurnal variation of wastewater isotopic composition reflected both the varying rates of foul sewage production and irregular dispersion effects in the pipe network. The latter suggest the existence of larger cumulative backwater zone volumes, which have not been attended to yet. Infiltrating groundwater contributed 39% (95% confidence interval = +/- 2.5%) of the total daily dry weather wastewater discharge. This paper discusses all relevant aspects for practical application of the method. It presents a comprehensive framework for uncertainty analysis and details on the detection and discrimination of possibly interfering effects.

  13. Factors responsible for a stable biosphere of silicon utilizing organisms

    Science.gov (United States)

    Mitra, D.; Das, S.

    2012-12-01

    -Pg boundary. All these evidences support the role of the unique characteristics of silicon utilizing organisms in maintaining their stable biosphere on earth.

  14. Over all separation factors for stable isotopes by gas centrifuge

    International Nuclear Information System (INIS)

    Chuntong Ying; Nie Yuguang; Zeng Shi; Shang Xiuyong; Wood, Houston G.

    1999-01-01

    The separation factor for the elements with molar wight differences, γ 0 , is an important characteristic parameter for separation of varied isotopes. Besides the dependence on construction parameters of the gas centrifuge it depends on many variables. Some of them are operation conditions, such as feeding flow rate F, pressure at wall p w , temperature T 0 and distribution temperature on the wall and others. Separation factor γ 0 depends on physical properties, such as molar weight M, viscosity μ, product of ρD, where ρ is density of working media and D is its diffusion coefficient. It was taken four examples: UF 6 , WF 6 , OsO 4 and Xe [ru

  15. Re-introduction of a novel approach to the use of stable isotopes in pharmacokinetic studies.

    Science.gov (United States)

    Parr, Alan; Gupta, Manish; Montague, Timothy H; Hoke, Frank

    2012-09-01

    The purpose of this investigation is to evaluate the scientific benefits of a novel approach in using stable isotopes to reduce the number of subjects needed to perform relative bioavailability and bioequivalence pharmacokinetic studies for formulations that are qualitatively and quantitatively the same and quality by design (QbD) pharmacokinetic studies. The stable isotope approach was investigated using simulations to determine the impact this approach would have on the estimation of variability and, subsequently, the sample size for a bioequivalence study. A biostudy was conducted in dogs in a two period crossover to explore the viability of the stable isotope approach. For a drug product with within-subject variability (CV(w)) of 50% and assuming a correlation of 0.95 between the enriched and non-enriched pharmacokinetics (PK), simulations showed that the variability can be reduced by 70% and the required sample size can be reduced by 90% while maintaining 90% power to demonstrate bioequivalence. The dog study showed a strong correlation (R(2), > 0.99) between the enriched and non-enriched area under the curve and maximum observed concentration, and a significant reduction in the variability (reduction in % coefficient of variation from 79.9% to 6.3%). Utilization of a stable isotope approach can markedly improve the efficiency and accuracy of bioavailability and bioequivalence studies particularly for highly variable drugs in formulations that are qualitatively and quantitatively the same and for studies designed for QbD investigations.

  16. Stable isotopic analysis of fossil chironomids as an approach to environmental reconstruction: state of development and future challenges

    Directory of Open Access Journals (Sweden)

    Oliver Heiri

    2012-10-01

    Full Text Available Remains of chironomid larvae, especially their strongly sclerotized head capsules, can be found abundantly and well preserved in most lake sediment records. These remains mainly consist of chitin and proteins and, since their chemical composition does not seem to be strongly affected by decompositional processes, they can be used to develop palaeoenvironmental reconstructions based on their stable isotopic composition. Here we review available stable isotope studies based on fossil chironomids and indicate future research necessary to further develop this still relatively new research approach. Efforts to produce stable isotope records based on fossil chironomids have mainly examined the elements H, N, C, and O. They have focussed on (1 developing the methodology for preparing samples for isotopic analysis, (2 laboratory studies cultivating chironomid larvae under controlled conditions to determine the factors affecting their stable isotopic composition, (3 ecosystem-scale studies relating stable isotopic measurements of fossil chironomid assemblages to environmental conditions, and (4 developing first down-core records describing past changes in the stable isotopic composition of chironomid assemblages. These studies have shown that chemical sample pretreatment may affect the isotopic composition for some elements. Laboratory runs suggest that the diet of the larvae influences their stable isotopic composition for H, N, C and O, whereas stable isotopes in the ambient water also strongly influence their oxygen and to a lesser extent hydrogen isotopic composition. These experiments also indicate only minor offsets between the nitrogen and carbon isotopic composition of chironomid soft tissue and the fossilizing head capsules, whereas for hydrogen and oxygen this offset remains to be explored. Though few datasets have been published, the available ecosystem studies and developed down-core sediment records indicate that stable isotopes in

  17. Approaches to daily body condition management in patients with stable chronic obstructive pulmonary disease.

    Science.gov (United States)

    Kawada, Terue

    2016-11-01

    To clarify the characteristics of sub-groups of patients with stable chronic obstructive pulmonary disease having similar approaches to daily body condition management. Prior literature has shed light on the experience of patients with chronic obstructive pulmonary disease and revealed that these patients engage in many activities and try different things in their daily lives to regulate and manage their body condition. The research so far has all been qualitative, comprising mostly interviews, and no quantitative studies have been performed. In this study, cluster analysis was used to show that subgroups of patients with similar characteristics undertake similar approaches to body condition management. Descriptive, correlational study. Invitations to participate in the survey were extended to patients with stable chronic obstructive pulmonary disease. Cluster analysis was performed on the basis of questionnaire scores relating to nine different categories of daily body condition management actions. The characteristics of the body condition management approaches, in each subgroup, were investigated using analysis of variance and multiple comparisons. The cluster analysis produced six subgroups, each defined by the effort expended as part of their body condition management. The subgroups also differed depending on patient age and disease severity. Body condition management approaches taken by patients with stable chronic obstructive pulmonary disease are overall, comprehensive approaches. Patients with chronic obstructive pulmonary disease were subgrouped based on their engagement in body conditioning. Relationships between the subgroups and the engagement in body conditioning, age and shortness of breath severity were observed. The care of patient support should be comprehensive and depend on their age and the duration of the disease. In addition, it should be long term and recognise that the patients are living their own respective lives. Such considerations and

  18. Discrimination factors of carbon and nitrogen stable isotopes in meerkat feces

    Directory of Open Access Journals (Sweden)

    Shaena Montanari

    2017-06-01

    Full Text Available Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals’ diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta, a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals.

  19. Discrimination factors of carbon and nitrogen stable isotopes in meerkat feces

    Science.gov (United States)

    2017-01-01

    Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals’ diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta), a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces) is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces) is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals. PMID:28626611

  20. Data-driven Approaches to Teaching Stable Isotopes in Hydrology and Environmental Geochemistry

    Science.gov (United States)

    Jefferson, A.; Merchant, W. R.; Dees, D.; Griffith, E. M.; Ortiz, J. D.

    2016-12-01

    Stable isotopes have revolutionized our understanding of watershed hydrology and other earth science processes. However, students may struggle to correctly interpret isotope ratios and few students understand how isotope measurements are made. New laser-based technologies lower the barrier to entry for giving students hands on experience with isotope measurements and data analysis. We hypothesizedthat integrating such activities into the curriculum would increase student content knowledge, perceptions, and motivation to learn. This project assessed the impact that different pedagogical approaches have on student learning of stable isotope concepts in upper-division geoscience courses. An isotope hydrograph separation module was developed and taught for a Watershed Hydrology course, and a Rayleigh distillation activity was developed and deployed for Environmental Geochemistry and Sedimentology/Stratigraphy classes. Groups of students were exposed to this content via (1) a lecture-only format; (2) a paper-based data analysis activity; and (3) hands-on data collection, sometimes including spectrometer analysis. Pre- and post-tests measured gains in content knowledge while approaches to learning and motivational questionnaires instruments were used to identify the effects of the classroom environment on learning approaches and motivation. Focus group interviews were also conducted to verify the quantitative data. All instructional styles appear to be equally effective at increasing student content knowledge of stable isotopes in the geosciences, but future studies need to move beyond "exam question" style assessment of learning. Our results may reflect that hands-on experiences are not new to upper-level geosciences students, because this is the way that many classes are taught in the geosciences (labs, field trips). Thus, active learning approaches may not have had the impact they would with other groups. The "messiness" of hands-on activities and authentic research

  1. Recent Bayesian stable-isotope mixing models are highly sensitive to variation in discrimination factors.

    Science.gov (United States)

    Bond, Alexander L; Diamond, Antony W

    2011-06-01

    Stable isotopes are now used widely in ecological studies, including diet reconstruction, where quantitative inferences about diet composition are derived from the use of mixing models. Recent Bayesian models (MixSIR, SIAR) allow users to incorporate variability in discrimination factors (delta13C or delta15N), or the amount of change in either delta13C or delta15N between prey and consumer, but to date there has been no systematic assessment of the effect of variation in delta13C or delta15N on model outputs. We used whole blood from Common Terns (Sterna hirundo) and muscle from their common prey items (fish and euphausiids) to build a series of mixing models in SIAR (stable isotope analysis in R) using various discrimination factors from the published literature for marine birds. The estimated proportion of each diet component was affected significantly by delta13C or delta15N. We also use recently published stable-isotope data on the reliance of critically endangered Balearic Shearwaters (Puffinus mauretanicus) on fisheries discards to show that discrimination factor choice can have profound implications for conservation and management actions. It is therefore crucial for researchers wishing to use mixing models to have an accurate estimate of delta13C and delta15N, because quantitative diet estimates can help to direct future research or prioritize conservation and management actions.

  2. Trophic discrimination factors of stable carbon and nitrogen isotopes in hair of corn fed wild boar.

    Directory of Open Access Journals (Sweden)

    Michaela Holá

    Full Text Available Stable isotope measurements are increasingly being used to gain insights into the nutritional ecology of many wildlife species and their role in ecosystem structure and function. Such studies require estimations of trophic discrimination factors (i.e. differences in the isotopic ratio between the consumer and its diet. Although trophic discrimination factors are tissue- and species-specific, researchers often rely on generalized, and fixed trophic discrimination factors that have not been experimentally derived. In this experimental study, captive wild boar (Sus scrofa were fed a controlled diet of corn (Zea mays, a popular and increasingly dominant food source for wild boar in the Czech Republic and elsewhere in Europe, and trophic discrimination factors for stable carbon (Δ13C and nitrogen (Δ15N isotopes were determined from hair samples. The mean Δ13C and Δ15N in wild boar hair were -2.3‰ and +3.5‰, respectively. Also, in order to facilitate future derivations of isotopic measurements along wild boar hair, we calculated the average hair growth rate to be 1.1 mm d(-1. Our results serve as a baseline for interpreting isotopic patterns of free-ranging wild boar in current European agricultural landscapes. However, future research is needed in order to provide a broader understanding of the processes underlying the variation in trophic discrimination factors of carbon and nitrogen across of variety of diet types.

  3. A Bayesian Nonparametric Approach to Factor Analysis

    DEFF Research Database (Denmark)

    Piatek, Rémi; Papaspiliopoulos, Omiros

    2018-01-01

    This paper introduces a new approach for the inference of non-Gaussian factor models based on Bayesian nonparametric methods. It relaxes the usual normality assumption on the latent factors, widely used in practice, which is too restrictive in many settings. Our approach, on the contrary, does...... not impose any particular assumptions on the shape of the distribution of the factors, but still secures the basic requirements for the identification of the model. We design a new sampling scheme based on marginal data augmentation for the inference of mixtures of normals with location and scale...... restrictions. This approach is augmented by the use of a retrospective sampler, to allow for the inference of a constrained Dirichlet process mixture model for the distribution of the latent factors. We carry out a simulation study to illustrate the methodology and demonstrate its benefits. Our sampler is very...

  4. A Fundamental Approach to Developing Aluminium based Bulk Amorphous Alloys based on Stable Liquid Metal Structures and Electronic Equilibrium - 154041

    Science.gov (United States)

    2017-03-28

    AFRL-AFOSR-JP-TR-2017-0027 A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal Structures and...to 16 Dec 2016 4.  TITLE AND SUBTITLE A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal...Air Force Research Laboratory for accurately predicting compositions of new amorphous alloys specifically based on aluminium with properties superior

  5. Trophic Interactions in Louisiana Salt Marshes: Combining Stomach Content, Stable Isotope, and Fatty Acid Approaches

    Science.gov (United States)

    Lopez-Duarte, P. C.; Able, K.; Fodrie, J.; McCann, M. J.; Melara, S.; Noji, C.; Olin, J.; Pincin, J.; Plank, K.; Polito, M. J.; Jensen, O.

    2016-02-01

    Multiple studies conducted over five years since the 2010 Macondo oil spill in the Gulf of Mexico indicate that oil impacts vary widely among taxonomic groups. For instance, fishes inhabiting the marsh surface show no clear differences in either community composition or population characteristics between oiled and unoiled sites, despite clear evidence of physiological impacts on individual fish. In contrast, marsh insects and spiders are sensitive to the effects of hydrocarbons. Both insects and spiders are components of the marsh food web and represent an important trophic link between marsh plants and higher trophic levels. Because differences in oil impacts throughout the marsh food web have the potential to significantly alter food webs and energy flow pathways and reduce food web resilience, our goal is to quantify differences in marsh food webs between oiled and unoiled sites to test the hypothesis that oiling has resulted in simpler and less resilient food webs. Diets and food web connections were quantified through a combination of stomach content, stable isotope, and fatty acid analysis. The combination of these three techniques provides a more robust approach to quantifying trophic relationships than any of these methods alone. Stomach content analysis provides a detailed snapshot of diets, while fatty acid and stable isotopes reflect diets averaged over weeks to months. Initial results focus on samples collected in May 2015 from a range of terrestrial and aquatic consumer species, including insects, mollusks, crustaceans, and piscivorous fishes.

  6. The human factors approach at EDF

    International Nuclear Information System (INIS)

    Colas, A.

    2004-01-01

    At the dawn of the 21st century, French electricity utility EDF is facing a number of major changes, in particular the liberalisation of European energy markets and the restructuring needed to cope with this development. EDF's approach to human factors (HF) aspects is also undergoing major changes, since people obviously play a predominant role in any organisational structure. (author)

  7. Stable personal attributes and a resilient approach to work and career

    Directory of Open Access Journals (Sweden)

    Jill Flint-Taylor

    2014-08-01

    Full Text Available Orientation: Recent research has suggested that personal resilience should be viewed in terms of process and outcome. This has implications for the study of resilience in the work context. Research purpose: The main research aim was to explore, at a detailed level, relationships between enduring personal characteristics and a resilient approach to work and career. Motivation for the study: Moving away from the idea of resilience as a specific trait or set of traits raises the question of how general personality and ability constructs influence a resilient approach. Research approach, design and method: This was an exploratory, quantitative study involving predictor (ability and personality and criterion (satisfaction and involvement data for 168 senior managers in five businesses within a retail and distribution group. Main findings: Evidence was found for differential relationships between personal attributes and a resilient approach (measured in terms of positive vs. negative perspectives on work and career. For example, the personality factor of Openness to Experience was negatively related to Organisation and Career Satisfaction, but positively related to Career and Job Involvement. Practical/managerial implications: In designing selection, development and employee survey procedures, organisations need to be aware of the differential nature of the relationships between attributes and a resilient approach to work and career. Contribution/value-add: The study brings together recent research on resilience, personal attributes and work outcomes, and supports the potential of general attribute models for studying and improving the process of developing and exercising a resilient approach in the work context.

  8. Stable personal attributes and a resilient approach to work and career

    Directory of Open Access Journals (Sweden)

    Jill Flint-Taylor

    2014-08-01

    Research purpose: The main research aim was to explore, at a detailed level, relationships between enduring personal characteristics and a resilient approach to work and career. Motivation for the study: Moving away from the idea of resilience as a specific trait or set of traits raises the question of how general personality and ability constructs influence a resilient approach. Research approach, design and method: This was an exploratory, quantitative study involving predictor (ability and personality and criterion (satisfaction and involvement data for 168 senior managers in five businesses within a retail and distribution group. Main findings: Evidence was found for differential relationships between personal attributes and a resilient approach (measured in terms of positive vs. negative perspectives on work and career. For example, the personality factor of Openness to Experience was negatively related to Organisation and Career Satisfaction, but positively related to Career and Job Involvement. Practical/managerial implications: In designing selection, development and employee survey procedures, organisations need to be aware of the differential nature of the relationships between attributes and a resilient approach to work and career. Contribution/value-add: The study brings together recent research on resilience, personal attributes and work outcomes, and supports the potential of general attribute models for studying and improving the process of developing and exercising a resilient approach in the work context.

  9. Flow-through SIP - A novel stable isotope probing approach limiting cross-feeding

    Science.gov (United States)

    Mooshammer, Maria; Kitzinger, Katharina; Schintlmeister, Arno; Kjedal, Henrik; Nielsen, Jeppe Lund; Nielsen, Per; Wagner, Michael

    2017-04-01

    Stable isotope probing (SIP) is a widely applied tool to link specific microbial populations to metabolic processes in the environment without the prerequisite of cultivation, which has greatly advanced our understanding of the role of microorganisms in biogeochemical cycling. SIP relies on tracing specific isotopically labeled substrates (e.g., 13C, 15N, 18O) into cellular biomarkers, such as DNA, RNA or phospholipid fatty acids, and is considered to be a robust technique to identify microbial populations that assimilate the labeled substrate. However, cross-feeding can occur when labeled metabolites are released from a primary consumer and then used by other microorganisms. This leads to erroneous identification of organisms that are not directly responsible for the process of interest, but are rather connected to primary consumers via a microbial food web. Here, we introduce a new approach that has the potential to eliminate the effect of cross-feeding in SIP studies and can thus also be used to distinguish primary consumers from other members of microbial food webs. In this approach, a monolayer of microbial cells are placed on a filter membrane, and labeled substrates are supplied by a continuous flow. By means of flow-through, labeled metabolites and degradation products are constantly removed, preventing secondary consumption of the substrate. We present results from a proof-of-concept experiment using nitrifiers from activated sludge as model system, in which we used fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes for identification of nitrifiers in combination with nanoscale secondary ion mass spectrometry (NanoSIMS) for visualization of isotope incorporation at the single-cell level. Our results show that flow-through SIP is a promising approach to significantly reduce cross-feeding and secondary substrate consumption in SIP experiments.

  10. What controls the stable isotope composition of precipitation in the Mekong Delta? A model-based statistical approach

    Science.gov (United States)

    Le Duy, Nguyen; Heidbüchel, Ingo; Meyer, Hanno; Merz, Bruno; Apel, Heiko

    2018-02-01

    This study analyzes the influence of local and regional climatic factors on the stable isotopic composition of rainfall in the Vietnamese Mekong Delta (VMD) as part of the Asian monsoon region. It is based on 1.5 years of weekly rainfall samples. In the first step, the isotopic composition of the samples is analyzed by local meteoric water lines (LMWLs) and single-factor linear correlations. Additionally, the contribution of several regional and local factors is quantified by multiple linear regression (MLR) of all possible factor combinations and by relative importance analysis. This approach is novel for the interpretation of isotopic records and enables an objective quantification of the explained variance in isotopic records for individual factors. In this study, the local factors are extracted from local climate records, while the regional factors are derived from atmospheric backward trajectories of water particles. The regional factors, i.e., precipitation, temperature, relative humidity and the length of backward trajectories, are combined with equivalent local climatic parameters to explain the response variables δ18O, δ2H, and d-excess of precipitation at the station of measurement. The results indicate that (i) MLR can better explain the isotopic variation in precipitation (R2 = 0.8) compared to single-factor linear regression (R2 = 0.3); (ii) the isotopic variation in precipitation is controlled dominantly by regional moisture regimes (˜ 70 %) compared to local climatic conditions (˜ 30 %); (iii) the most important climatic parameter during the rainy season is the precipitation amount along the trajectories of air mass movement; (iv) the influence of local precipitation amount and temperature is not significant during the rainy season, unlike the regional precipitation amount effect; (v) secondary fractionation processes (e.g., sub-cloud evaporation) can be identified through the d-excess and take place mainly in the dry season, either locally

  11. What controls the stable isotope composition of precipitation in the Mekong Delta? A model-based statistical approach

    Directory of Open Access Journals (Sweden)

    N. Le Duy

    2018-02-01

    Full Text Available This study analyzes the influence of local and regional climatic factors on the stable isotopic composition of rainfall in the Vietnamese Mekong Delta (VMD as part of the Asian monsoon region. It is based on 1.5 years of weekly rainfall samples. In the first step, the isotopic composition of the samples is analyzed by local meteoric water lines (LMWLs and single-factor linear correlations. Additionally, the contribution of several regional and local factors is quantified by multiple linear regression (MLR of all possible factor combinations and by relative importance analysis. This approach is novel for the interpretation of isotopic records and enables an objective quantification of the explained variance in isotopic records for individual factors. In this study, the local factors are extracted from local climate records, while the regional factors are derived from atmospheric backward trajectories of water particles. The regional factors, i.e., precipitation, temperature, relative humidity and the length of backward trajectories, are combined with equivalent local climatic parameters to explain the response variables δ18O, δ2H, and d-excess of precipitation at the station of measurement. The results indicate that (i MLR can better explain the isotopic variation in precipitation (R2  =  0.8 compared to single-factor linear regression (R2  =  0.3; (ii the isotopic variation in precipitation is controlled dominantly by regional moisture regimes (∼ 70 % compared to local climatic conditions (∼ 30 %; (iii the most important climatic parameter during the rainy season is the precipitation amount along the trajectories of air mass movement; (iv the influence of local precipitation amount and temperature is not significant during the rainy season, unlike the regional precipitation amount effect; (v secondary fractionation processes (e.g., sub-cloud evaporation can be identified through the d-excess and take

  12. A Combined Stable Isotope And Machine Learning Approach To Quantify And Classify Of Nitrate Pollution Sources

    Science.gov (United States)

    Boeckx, P. F.; Xue, D.; De Baets, B.

    2011-12-01

    Stable isotope analyses of NO3- (δ15N and δ18O) are widely used to determine the sources of nitrate pollution in water. The objective of our study was (1) to quantify NO3- sources in surface water and to classify surface waters in NO3- pollution classes via a combined stable isotope and machine learning approach; and (2) to assess a decision tree model with physicochemical data for retrieving the latter classification. A logical approach has been followed: (1) 2-year monthly sampling of 30 sampling points from different river basins in Belgium, which were classified into 5 different NO3- pollution classes using experts knowledge (Agriculture (A), Agriculture with groundwater compensation (AGC), Combination of agriculture and horticulture (AH), Greenhouses in an agricultural area (G) and Households (H)); (2) estimating proportional NO3- source contribution per NO3- pollution class by applying a Bayesian isotopic mixing model (SIAR) for measured isotopic data of NO3-; (3) re-classifying the 30 sampling points into NO3- pollution classes via a k-means clustering of the SIAR outputs; and (4) building a decision tree model using physicochemical data to retrieve expert knowledge and k-means clustering classification. SIAR successfully estimated proportional contribution ranges of five potential NO3- sources: NO3- in precipitation, NO3- in fertilizer, NH4+ in fertilizer and precipitation, manure and sewage and soil N. For classes A, AGC, AH and H in winter manure and sewage were major (40 - 60%), NO3- in precipitation minor (pollution classes were optimal for both winter and summer. Thus the 30 sampling points were divided into four classes: classes A, class AGC, class G, and class H (class AH was not retained). Finally, a decision tree model built on physicochemical data using expert classification labels or k-means clustering labels could retrieve ca. 70% of the nitrate pollution classes in both cases. The later suggests that physicochemical data could be applied to

  13. Estimating phreatic evaporation in irrigated areas using a stable isotope approach

    Science.gov (United States)

    Barthold, F. K.; Umirzakov, G.; Schneider, K.; Stulina, G.; Frede, H.; Breuer, L.

    2011-12-01

    Central Asia is characterized by continental arid climate conditions. Mean annual precipitation is 170 mm with a potential evapotranspiration rate of 1200 mm/a. In addition, many regions are affected by a non-sustainable use of the water resources. 90% of the water resources are used for irrigation purposes to grow e.g. cotton and wheat, especially in Uzbekistan. Large amounts of water are needed for cotton growth. Not only does the plant itself require large amounts of water but a substantial part of the water use is ascribed to the inefficient irrigation system and management. The irrigation infrastructure is old and not maintained well and irrigation management is inadequate. Groundwater level rise has been observed in irrigated areas as a result of the inefficient irrigation practices. Capillary raised groundwater is particularly prone to evaporation as it gets closer to the soil surface. The general objective of this study is to quantify the amount of groundwater (or phreatic) evaporation that is due to groundwater table rise on irrigated fields. In this study, we present an approach where we are using stable isotopes of water to estimate phreatic evaporation on irrigated fields. Our specific objective is to estimate phreatic evaporation (Ep) in relation to the groundwater level and varying soil types (sandy, loamy and clay loamy). We chose a stable water isotopes approach to estimate Ep. For this purpose, soil samples along a depth profile were sampled on sites with different groundwater levels and soil types. Samples were taken in 10 cm increments down to the groundwater level. Soil water was extracted using a cryogenic vacuum distillation and the extracted soil water was analyzed for its composition of stable water isotopes, δD and δ18O, using a Liquid Water Isotope Analyzer (Los Gatos Research, Inc.). Ep was calculated by fitting an exponential function to the experimental isotope soil profile. Our results show that in sandy and loamy soils, enrichment

  14. Numerically stable approach for high-precision orbit integration using Encke's method and equinoctial elements

    Science.gov (United States)

    Ellmer, Matthias; Mayer-Gürr, Torsten

    2016-04-01

    Future gravity missions like GRACE-FO and beyond will deliver low-low satellite-to-satellite (ll-sst) ranging measurements of much increased precision. This necessitates a re-evaluation of the processes used in gravity field determination with an eye to numerical stability. When computing gravity fields from ll-sst data, precise positions of both satellites are needed in the setup of the observation equations. These positions thus have an immediate effect on the sought-after gravity field parameters. We use reduced-dynamic orbits which are computed through integration of all accelerations experienced by the satellite, as determined through a priori models and observed through the accelerometer. Our simulations showed that computing the orbit of the satellite through complete integration of all acting forces leads to numeric instabilities magnitudes larger than the expected ranging accuracy. We introduce a numerically stable approach employing a best-fit keplerian reference orbit based on Encke's method. Our investigations revealed that using canonical formulations for the evaluation of the reference keplerian orbit and accelerations lead to insufficient precision, necessitating an alternative formulation like the equinoctial elements.

  15. Dietary plasticity of generalist and specialist ungulates in the Namibian Desert: a stable isotopes approach.

    Science.gov (United States)

    Lehmann, David; Mfune, John Kazgeba Elijah; Gewers, Erick; Cloete, Johann; Brain, Conrad; Voigt, Christian Claus

    2013-01-01

    Desert ungulates live in adverse ecosystems that are particularly sensitive to degradation and global climate change. Here, we asked how two ungulate species with contrasting feeding habits, grazing gemsbok (Oryx g. gazella) and browsing springbok (Antidorcas marsupialis), respond to an increase in food availability during a pronounced rain period. We used a stable isotope approach to delineate the feeding habits of these two ungulates in the arid Kunene Region of Namibia. Our nineteen months field investigation included two time periods of drought when food availability for ungulates was lowest and an intermediate period with extreme, unusual rainfalls. We documented thirteen isotopically distinct food sources in the isotopic space of the study area. Our results indicated a relatively high dietary plasticity of gemsbok, which fed on a mixture of plants, including more than 30% of C3 plants during drought periods, but almost exclusively on C4 and CAM plant types when food was plentiful. During drought periods, the inferred gemsbok diets also consisted of up to 25% of Euphorbia damarana; an endemic CAM plant that is rich in toxic secondary plant compounds. In contrast, springbok were generalists, feeding on a higher proportion of C3 than C4/CAM plants, irrespective of environmental conditions. Our results illustrate two dietary strategies in gemsbok and springbok which enable them to survive and coexist in the hostile Kunene arid ecosystem.

  16. Multidimensional Perovskites: A Mixed Cation Approach Towards Ambient Stable and Tunable Perovskite Photovoltaics.

    Science.gov (United States)

    Koh, Teck Ming; Thirumal, Krishnamoorthy; Soo, Han Sen; Mathews, Nripan

    2016-09-22

    Although halide perovskites are able to deliver high power conversion efficiencies, their ambient stability still remains an obstacle for commercialization. Thus, promoting the ambient stability of perovskites has become a key research focus. In this review, we highlight the sources of instability in conventional 3 D perovskites, including water intercalation, ion migration, and thermal decomposition. Recently, the multidimensional perovskites approach has become one of the most promising strategies to enhance the stability of perovskites. As compared to pure 2 D perovskites, multidimensional perovskites typically possess more ideal band gaps, better charge transport, and lower exciton binding energy, which are essential for photovoltaic applications. The larger organic cations in multidimensional perovskites could also be more chemically stable at higher temperatures than the commonly used methylammonium cation. By combining 3 D and 2 D perovskites to form multidimensional perovskites, halide perovskite photovoltaics can attain both high efficiency and increased stability. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Factors influencing stable isotopes and growth of algae in oil sands aquatic reclamation.

    Science.gov (United States)

    Boutsivongsakd, Monique; Farwell, Andrea J; Chen, Hao; Dixon, D George

    2015-01-01

    Previous studies reported (15)N enrichment of biota in reclamation wetlands that contain oil sands processed material (e.g., processed water and tailings); however, there is little information on the factors controlling (15)N enrichment in these systems. In this microcosm study, the aim was to examine stable C and N isotopes and growth (chlorophyll a [chl a] and dry weight) of algae as a function of exposure to different sources and concentrations of water-soluble fractions (WSF) derived from tailings. Two sources of tailings including mature fine tailings (MFT) and consolidated tailings (CT) and peat-mineral overburden were utilized to generate separate WSF that differed in water quality. In general, there was (15)N enrichment of filamentous algae along the increasing gradient of WSF/nutrient concentrations in both CT and peat microcosms, and among the different sources, algae were more (15)N enriched in CT WSF than in peat WSF. Growth of filamentous algae was inhibited at higher WSF concentrations, possibly due to reduced light availability at elevated levels of fine clay particles in MFT microcosms and colored dissolved organic carbon (DOC) in peat microcosms. Filamentous algae displayed lower biomass and (15)N depletion in 100% peat WSF. This study indicated that both the quality (source) and quantity of WSF affected algal growth and directly and/or indirectly influenced δ(15)N of algae. The distinct (15)N enrichment of primary producers derived from tailings suggest that stable N isotopes might be useful to trace exposure to oil sands processed material in biota that utilize these resources in reclaimed systems constructed with tailings or natural systems that receive tailings dyke seepage.

  18. A modelling approach to find stable and reliable soil organic carbon values for further regionalization.

    Science.gov (United States)

    Bönecke, Eric; Franko, Uwe

    2015-04-01

    Soil organic matter (SOM) and carbon (SOC) might be the most important components to describe soil fertility of agricultural used soils. It is sensitive to temporal and spatial changes due to varying weather conditions, uneven crops and soil management practices and still struggles with providing reliable delineation of spatial variability. Soil organic carbon, furthermore, is an essential initial parameter for dynamic modelling, understanding e.g. carbon and nitrogen processes. Alas it requires cost and time intensive field and laboratory work to attain and using this information. The objective of this study is to assess an approach that reduces efforts of laboratory and field analyses by using method to find stable initial soil organic carbon values for further soil process modelling and regionalization on field scale. The demand of strategies, technics and tools to improve reliable soil organic carbon high resolution maps and additionally reducing cost constraints is hence still facing an increasing attention of scientific research. Although, it is nowadays a widely used practice, combining effective sampling schemes with geophysical sensing techniques, to describe within-field variability of soil organic carbon, it is still challenging large uncertainties, even at field scale in both, science and agriculture. Therefore, an analytical and modelling approach might facilitate and improve this strategy on small and large field scale. This study will show a method, how to find reliable steady state values of soil organic carbon at particular points, using the approved soil process model CANDY (Franko et al. 1995). It is focusing on an iterative algorithm of adjusting the key driving components: soil physical properties, meteorological data and management information, for which we quantified the input and the losses of soil carbon (manure, crop residues, other organic inputs, decomposition, leaching). Furthermore, this approach can be combined with geophysical

  19. Stable isotope switching (SIS): a new stable isotope probing (SIP) approach to determine carbon flow in the soil food web and dynamics in organic matter pools.

    Science.gov (United States)

    Maxfield, P J; Dildar, N; Hornibrook, E R C; Stott, A W; Evershed, R P

    2012-04-30

    Recent advances in stable isotope probing (SIP) have allowed direct linkage of microbial population structure and function. This paper details a new development of SIP, Stable Isotope Switching (SIS), which allows the simultaneous assessment of carbon (C) uptake, turnover and decay, and the elucidation of soil food webs within complex soils or sedimentary matrices. SIS utilises a stable isotope labelling approach whereby the (13)C-labelled substrate is switched part way through the incubation to a natural abundance substrate. A (13)CH(4) SIS study of landfill cover soils from Odcombe (Somerset, UK) was conducted. Carbon assimilation and dissimilation processes were monitored through bulk elemental analysis isotope ratio mass spectrometry and compound-specific gas chromatography/combustion/isotope ratio mass spectrometry, targeting a wide range of biomolecular components including: lipids, proteins and carbohydrates. Carbon assimilation by primary consumers (methanotrophs) and sequential assimilation into secondary (Gram-negative and -positive bacteria) and tertiary consumers (Eukaryotes) was observed. Up to 45% of the bacterial membrane lipid C was determined to be directly derived from CH(4) and at the conclusion of the experiment ca. 50% of the bulk soil C derived directly from CH(4) was retained within the soil. This is the first estimate of soil organic carbon derived from CH(4) and it is comparable with levels observed in lakes that have high levels of benthic methanogenesis. SIS opens the way for a new generation of SIP studies aimed at elucidating total C dynamics (incorporation, turnover and decay) at the molecular level in a wide range of complex environmental and biological matrices. Copyright © 2012 John Wiley & Sons, Ltd.

  20. Toward a simple, repeatable, non-destructive approach to measuring stable-isotope ratios of water within tree stems

    Science.gov (United States)

    Raulerson, S.; Volkmann, T.; Pangle, L. A.

    2017-12-01

    Traditional methodologies for measuring ratios of stable isotopes within the xylem water of trees involve destructive coring of the stem. A recent approach involves permanently installed probes within the stem, and an on-site assembly of pumps, switching valves, gas lines, and climate-controlled structure for field deployment of a laser spectrometer. The former method limits the possible temporal resolution of sampling, and sample size, while the latter may not be feasible for many research groups. We present results from initial laboratory efforts towards developing a non-destructive, temporally-resolved technique for measuring stable isotope ratios within the xylem flow of trees. Researchers have used direct liquid-vapor equilibration as a method to measure isotope ratios of the water in soil pores. Typically, this is done by placing soil samples in a fixed container, and allowing the liquid water within the soil to come into isotopic equilibrium with the headspace of the container. Water can also be removed via cryogenic distillation or azeotropic distillation, with the resulting liquid tested for isotope ratios. Alternatively, the isotope ratios of the water vapor can be directly measured using a laser-based water vapor isotope analyzer. Well-established fractionation factors and the isotope ratios in the vapor phase are then used to calculate the isotope ratios in the liquid phase. We propose a setup which would install a single, removable chamber onto a tree, where vapor samples could non-destructively and repeatedly be taken. These vapor samples will be injected into a laser-based isotope analyzer by a recirculating gas conveyance system. A major part of what is presented here is in the procedure of taking vapor samples at 100% relative humidity, appropriately diluting them with completely dry N2 calibration gas, and injecting them into the gas conveyance system without inducing fractionation in the process. This methodology will be helpful in making

  1. Assessing the functional diversity of herbivorous reef fishes using a compound-specific stable isotope approach

    KAUST Repository

    Tietbohl, Matthew

    2016-12-01

    Herbivorous coral reef fishes play an important role in helping to structure their environment directly by consuming algae and indirectly by promoting coral health and growth. These fishes are generally separated into three broad groups: browsers, grazers, and excavators/scrapers, with these groupings often thought to have a fixed general function and all fishes within a group thought to have similar ecological roles. This categorization assumes a high level of functional redundancy within herbivorous fishes. However, recent evidence questions the use of this broad classification scheme, and posits that there may actually be more resource partitioning within these functional groupings. Here, I use a compound-specific stable isotope approach (CSIA) to show there appears to be a greater diversity of functional roles than previously assumed within broad functional groups. The δ13C signatures from essential amino acids of reef end-members (coral, macroalgae, detritus, and phytoplankton) and fish muscle were analyzed to investigate differences in resource use between fishes. Most end-members displayed clear isotopic differences, and most fishes within functional groups were dissimilar in their isotopic signature, implying differences in the resources they target. No grazers closely resembled each other isotopically, implying a much lower level of functional redundancy within this group; scraping parrotfish were also distinct from excavating parrotfish and to a lesser degree distinct between scrapers. This study highlights the potential of CSIA to help distinguish fine-scale ecological differences within other groups of reef organisms as well. These results question the utility of lumping nominally herbivorous fishes into broad groups with assumed similar roles. Given the apparent functional differences between nominally herbivorous reef fishes, it is important for managers to incorporate the diversity of functional roles these fish play.

  2. Novel Approach for High-Throughput Metabolic Screening of Whole Plants by Stable Isotopes.

    Science.gov (United States)

    Dersch, Lisa Maria; Beckers, Veronique; Rasch, Detlev; Melzer, Guido; Bolten, Christoph; Kiep, Katina; Becker, Horst; Bläsing, Oliver Ernst; Fuchs, Regine; Ehrhardt, Thomas; Wittmann, Christoph

    2016-05-01

    Here, we demonstrate whole-plant metabolic profiling by stable isotope labeling and combustion isotope-ratio mass spectrometry for precise quantification of assimilation, translocation, and molecular reallocation of (13)CO2 and (15)NH4NO3 The technology was applied to rice (Oryza sativa) plants at different growth stages. For adult plants, (13)CO2 labeling revealed enhanced carbon assimilation of the flag leaf from flowering to late grain-filling stage, linked to efficient translocation into the panicle. Simultaneous (13)CO2 and (15)NH4NO3 labeling with hydroponically grown seedlings was used to quantify the relative distribution of carbon and nitrogen. Two hours after labeling, assimilated carbon was mainly retained in the shoot (69%), whereas 7% entered the root and 24% was respired. Nitrogen, taken up via the root, was largely translocated into the shoot (85%). Salt-stressed seedlings showed decreased uptake and translocation of nitrogen (69%), whereas carbon metabolism was unaffected. Coupled to a gas chromatograph, labeling analysis provided enrichment of proteinogenic amino acids. This revealed significant protein synthesis in the panicle of adult plants, whereas protein biosynthesis in adult leaves was 8-fold lower than that in seedling shoots. Generally, amino acid enrichment was similar among biosynthetic families and allowed us to infer labeling dynamics of their precursors. On this basis, early and strong (13)C enrichment of Embden-Meyerhof-Parnas pathway and pentose phosphate pathway intermediates indicated high activity of these routes. Applied to mode-of-action analysis of herbicides, the approach showed severe disturbance in the synthesis of branched-chain amino acids upon treatment with imazapyr. The established technology displays a breakthrough for quantitative high-throughput plant metabolic phenotyping. © 2016 American Society of Plant Biologists. All Rights Reserved.

  3. A Metal Stable Isotope Approach to Understanding Uranium Mobility Across Roll Front Redox Boundaries

    Science.gov (United States)

    Brown, S. T.; Basu, A.; Christensen, J. N.; DePaolo, D. J.; Heikoop, J. M.; Reimus, P. W.; Maher, K.; Weaver, K. L.

    2015-12-01

    Sedimentary roll-front uranium (U) ore deposits are the principal source of U for nuclear fuel in the USA and an important part of the current all-of-the-above energy strategy. Mining of roll-front U ore in the USA is primarily by in situ alkaline oxidative dissolution of U minerals. There are significant environmental benefits to in situ mining including no mine tailings or radioactive dust, however, the long-term immobilization of U in the aquifer after the completion of mining remains uncertain. We have utilized the metal stable isotopes U, Se and Mo in groundwater from roll-front mines in Texas and Wyoming to quantify the aquifer redox conditions and predict the onset of U reduction after post mining aquifer restoration. Supporting information from the geochemistry of groundwater and aquifer sediments are used to understand the transport of U prior to and after in situ mining. Groundwater was collected across 4 mining units at the Rosita mine in the Texas coastal plain and 2 mining units at the Smith Ranch mine in the Powder River Basin, Wyoming. In general, the sampled waters are moderately reducing and ore zone wells contain the highest aqueous U concentrations. The lowest U concentrations occur in monitoring wells downgradient of the ore zone. 238U/235U is lowest in downgradient wells and is correlated with aqueous U concentrations. Rayleigh distillation models of the 238U/235U are consistent with U isotope fractionation factors of 1.0004-1.001, similar to lab-based studies. Based on these results we conclude that redox reactions continue to affect U distribution in the ore zone and downgradient regions. We also measured aqueous selenium isotope (δ82Se) and molybdenum isotope (δ98Mo) compositions in the Rosita groundwater. Se(VI) primarily occurs in the upgradient wells and is absent in most ore zone and downgradient wells. Rayleigh distillation models suggest reduction of Se(VI) along the groundwater flow path and when superimposed on the U isotope data

  4. An Approach to Stable Walking over Uneven Terrain Using a Reflex-Based Adaptive Gait

    Directory of Open Access Journals (Sweden)

    Umar Asif

    2011-01-01

    Full Text Available This paper describes the implementation of an adaptive gait in a six-legged walking robot that is capable of generating reactive stepping actions with the same underlying control methodology as an insect for stable walking over uneven terrains. The proposed method of gait generation uses feedback data from onboard sensors to generate an adaptive gait in order to surmount obstacles, gaps and perform stable walking. The paper addresses its implementation through simulations in a visual dynamic simulation environment. Finally the paper draws conclusions about the significance and performance of the proposed gait in terms of tracking errors while navigating in difficult terrains.

  5. Predictive factors for functional outcome and failure in angular stable osteosynthesis of the proximal humerus.

    LENUS (Irish Health Repository)

    Hardeman, Francois

    2012-02-01

    Angular stable osteosynthesis has become the gold standard in the operative treatment of proximal humeral fractures. The aim of this article is to determine the indications for osteosynthesis versus primary arthroplasty based on clinical and radiological parameters.

  6. Seasonal variation in the diet of spoonbill chicks in the Wadden Sea : A stable isotopes approach

    NARCIS (Netherlands)

    El-Hacen, El-Hacen Mohamed; Piersma, Theunis; Jouta, Jeltje; Overdijk, Otto; Lok, Tamar

    We used stable isotope tracers in the growing primary feathers of Eurasian Spoonbill chicks (Platalea leucorodia leucorodia) to study seasonal variation in their diet on one of the Frisian islands, Schiermonnikoog, The Netherlands. Using growing individual primaries as natural samplers over time,

  7. Participatory Common Learning in Groups of Dairy Farmers in Uganda (FFS approach) and Danish Stable Schools

    DEFF Research Database (Denmark)

    Vaarst, Mette

    on a Master Thesis in Health Anthropology and a mini manual to the so-called Stable Schools. Improvements of farming practices should be based on the context of the individual farm and include the goals of the farmer and the farming system. This should be the case in all types of farming systems. Viewing...

  8. Understanding repetitive travel mode choices in a stable context: A panel study approach

    DEFF Research Database (Denmark)

    Thøgersen, John

    2006-01-01

    It is argued that most travel mode choices are repetitive and made in a stable context. As an example, the everyday use of public transport is analyzed based on a panel survey with a random sample of about 1300 Danish residents interviewed up to three times in the period 1998-2000. The use...

  9. Historical and contemporary stable isotope tracer approaches to studying mammalian protein metabolism

    Science.gov (United States)

    2016-01-01

    Over a century ago, Frederick Soddy provided the first evidence for the existence of isotopes; elements that occupy the same position in the periodic table are essentially chemically identical but differ in mass due to a different number of neutrons within the atomic nucleus. Allied to the discovery of isotopes was the development of some of the first forms of mass spectrometers, driven forward by the Nobel laureates JJ Thomson and FW Aston, enabling the accurate separation, identification, and quantification of the relative abundance of these isotopes. As a result, within a few years, the number of known isotopes both stable and radioactive had greatly increased and there are now over 300 stable or radioisotopes presently known. Unknown at the time, however, was the potential utility of these isotopes within biological disciplines, it was soon discovered that these stable isotopes, particularly those of carbon (13C), nitrogen (15N), oxygen (18O), and hydrogen (2H) could be chemically introduced into organic compounds, such as fatty acids, amino acids, and sugars, and used to “trace” the metabolic fate of these compounds within biological systems. From this important breakthrough, the age of the isotope tracer was born. Over the following 80 yrs, stable isotopes would become a vital tool in not only the biological sciences, but also areas as diverse as forensics, geology, and art. This progress has been almost exclusively driven through the development of new and innovative mass spectrometry equipment from IRMS to GC‐MS to LC‐MS, which has allowed for the accurate quantitation of isotopic abundance within samples of complex matrices. This historical review details the development of stable isotope tracers as metabolic tools, with particular reference to their use in monitoring protein metabolism, highlighting the unique array of tools that are now available for the investigation of protein metabolism in vivo at a whole body down to a single protein level

  10. Stable-isotope and solute-chemistry approaches to flow characterization in a forested tropical watershed, Luquillo Mountains, Puerto Rico

    Science.gov (United States)

    Scholl, Martha A.; Shanley, James B.; Murphy, Sheila F.; Willenbring, Jane K; Occhi, Marcie; González, Grizelle

    2015-01-01

    The prospect of changing climate has led to uncertainty about the resilience of forested mountain watersheds in the tropics. In watersheds where frequent, high rainfall provides ample runoff, we often lack understanding of how the system will respond under conditions of decreased rainfall or drought. Factors that govern water supply, such as recharge rates and groundwater storage capacity, may be poorly quantified. This paper describes 8-year data sets of water stable isotope composition (δ2H and δ18O) of precipitation (4 sites) and a stream (1 site), and four contemporaneous stream sample sets of solute chemistry and isotopes, used to investigate watershed response to precipitation inputs in the 1780-ha Río Mameyes basin in the Luquillo Mountains of northeastern Puerto Rico. Extreme δ2H and δ18O values from low-pressure storm systems and the deuterium excess (d-excess) were useful tracers of watershed response in this tropical system. A hydrograph separation experiment performed in June 2011 yielded different but complementary information from stable isotope and solute chemistry data. The hydrograph separation results indicated that 36% of the storm rain that reached the soil surface left the watershed in a very short time as runoff. Weathering-derived solutes indicated near-stream groundwater was displaced into the stream at the beginning of the event, followed by significant dilution. The more biologically active solutes exhibited a net flushing behavior. The d-excess analysis suggested that streamflow typically has a recent rainfall component (∼25%) with transit time less than the sampling resolution of 7 days, and a more well-mixed groundwater component (∼75%). The contemporaneous stream sample sets showed an overall increase in dissolved solute concentrations with decreasing elevation that may be related to groundwater inputs, different geology, and slope position. A considerable amount of water from rain events runs off as quickflow and bypasses

  11. Stable isotope discrimination factors and between-tissue isotope comparisons for bone and skin from captive and wild green sea turtles (Chelonia mydas).

    Science.gov (United States)

    Turner Tomaszewicz, Calandra N; Seminoff, Jeffrey A; Price, Mike; Kurle, Carolyn M

    2017-11-30

    The ecological application of stable isotope analysis (SIA) relies on taxa- and tissue-specific stable carbon (Δ 13 C) and nitrogen (Δ 15 N) isotope discrimination factors, determined with captive animals reared on known diets for sufficient time to reflect dietary isotope ratios. However, captive studies often prohibit lethal sampling, are difficult with endangered species, and reflect conditions not experienced in the wild. We overcame these constraints and determined the Δ 13 C and Δ 15 N values for skin and cortical bone from green sea turtles (Chelonia mydas) that died in captivity and evaluated the utility of a mathematical approach to predict discrimination factors. Using stable carbon (δ 13 C values) and nitrogen (δ 15 N values) isotope ratios from captive and wild turtles, we established relationships between bone stable isotope (SI) ratios and those from skin, a non-lethally sampled tissue, to facilitate comparisons of SI ratios among studies using multiple tissues. The mean (±SD) Δ 13 C and Δ 15 N values (‰) between skin and bone from captive turtles and their diet (non-lipid-extracted) were 2.3 ± 0.3 and 4.1 ± 0.4 and 2.1 ± 0.6 and 5.1 ± 1.1, respectively. The mathematically predicted Δ 13 C and Δ 15 N values were similar (to within 1‰) to the experimentally derived values. The mean δ 15 N values from bone were higher than those from skin for captive (+1.0 ± 0.9‰) and wild (+0.8 ± 1.0‰) turtles; the mean δ 13 C values from bone were lower than those from skin for wild turtles (-0.6 ± 0.9‰), but the same as for captive turtles. We used linear regression equations to describe bone vs skin relationships and create bone-to-skin isotope conversion equations. For sea turtles, we provide the first (a) bone-diet SI discrimination factors, (b) comparison of SI ratios from individual-specific bone and skin, and (c) evaluation of the application of a mathematical approach to predict stable isotope discrimination factors. Our approach

  12. The evolution of stable magnetic fields in stars: an analytical approach

    Science.gov (United States)

    Mestel, Leon; Moss, David

    2010-07-01

    The absence of a rigorous proof of the existence of dynamically stable, large-scale magnetic fields in radiative stars has been for many years a missing element in the fossil field theory for the magnetic Ap/Bp stars. Recent numerical simulations, by Braithwaite & Spruit and Braithwaite & Nordlund, have largely filled this gap, demonstrating convincingly that coherent global scale fields can survive for times of the order of the main-sequence lifetimes of A stars. These dynamically stable configurations take the form of magnetic tori, with linked poloidal and toroidal fields, that slowly rise towards the stellar surface. This paper studies a simple analytical model of such a torus, designed to elucidate the physical processes that govern its evolution. It is found that one-dimensional numerical calculations reproduce some key features of the numerical simulations, with radiative heat transfer, Archimedes' principle, Lorentz force and Ohmic decay all playing significant roles.

  13. New approaches for stable isotope ratio measurements. Proceedings of an advisory group meeting

    International Nuclear Information System (INIS)

    2001-10-01

    This report includes a summary of discussions at the meeting and contributions on isotope applications in a range of specific biogeochemical fields using the new analytical techniques. It is expected to serve as a useful reference for researchers and laboratory managers who plan to develop or apply state-of-the-art stable isotope techniques. Individual contributions contained in this book have been indexed separately

  14. A novel Lagrangian approach for the stable numerical simulation of fault and fracture mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, Andrea; Ferronato, Massimiliano, E-mail: massimiliano.ferronato@unipd.it; Janna, Carlo; Teatini, Pietro

    2016-06-01

    The simulation of the mechanics of geological faults and fractures is of paramount importance in several applications, such as ensuring the safety of the underground storage of wastes and hydrocarbons or predicting the possible seismicity triggered by the production and injection of subsurface fluids. However, the stable numerical modeling of ground ruptures is still an open issue. The present work introduces a novel formulation based on the use of the Lagrange multipliers to prescribe the constraints on the contact surfaces. The variational formulation is modified in order to take into account the frictional work along the activated fault portion according to the principle of maximum plastic dissipation. The numerical model, developed in the framework of the Finite Element method, provides stable solutions with a fast convergence of the non-linear problem. The stabilizing properties of the proposed model are emphasized with the aid of a realistic numerical example dealing with the generation of ground fractures due to groundwater withdrawal in arid regions. - Highlights: • A numerical model is developed for the simulation of fault and fracture mechanics. • The model is implemented in the framework of the Finite Element method and with the aid of Lagrange multipliers. • The proposed formulation introduces a new contribution due to the frictional work on the portion of activated fault. • The resulting algorithm is highly non-linear as the portion of activated fault is itself unknown. • The numerical solution is validated against analytical results and proves to be stable also in realistic applications.

  15. A Stable-Isotope Mass Spectrometry-Based Metabolic Footprinting Approach to Analyze Exudates from Phytoplankton

    Directory of Open Access Journals (Sweden)

    Mark R. Viant

    2013-10-01

    Full Text Available Phytoplankton exudates play an important role in pelagic ecology and biogeochemical cycles of elements. Exuded compounds fuel the microbial food web and often encompass bioactive secondary metabolites like sex pheromones, allelochemicals, antibiotics, or feeding attractants that mediate biological interactions. Despite this importance, little is known about the bioactive compounds present in phytoplankton exudates. We report a stable-isotope metabolic footprinting method to characterise exudates from aquatic autotrophs. Exudates from 13C-enriched alga were concentrated by solid phase extraction and analysed by high-resolution Fourier transform ion cyclotron resonance mass spectrometry. We used the harmful algal bloom forming dinoflagellate Alexandrium tamarense to prove the method. An algorithm was developed to automatically pinpoint just those metabolites with highly 13C-enriched isotope signatures, allowing us to discover algal exudates from the complex seawater background. The stable-isotope pattern (SIP of the detected metabolites then allowed for more accurate assignment to an empirical formula, a critical first step in their identification. This automated workflow provides an effective way to explore the chemical nature of the solutes exuded from phytoplankton cells and will facilitate the discovery of novel dissolved bioactive compounds.

  16. Construct the stable vendor managed inventory partnership through a profit-sharing approach

    Science.gov (United States)

    Li, S.; Yu, Z.; Dong, M.

    2015-01-01

    In real life, the vendor managed inventory (VMI) model is not always a stable supply chain partnership. This paper proposes a cooperative game based profit-sharing method to stabilize the VMI partnership. Specifically, in a B2C setting, we consider a VMI program including a manufacturer and multiple online retailers. The manufacturer provides the finished product at the equal wholesale price to multiple online retailers. The online retailers face the same customer demand information. We offer the model to compute the increased profits generated by information sharing for total possible VMI coalitions. Using the solution concept of Shapley value, the profit-sharing scheme is produced to fairly divide the total increased profits among the VMI members. We find that under a fair allocation scheme, the higher inventory cost of one VMI member increases the surplus of the other members. Furthermore, the manufacturer is glad to increase the size of VMI coalition, whereas, the retailers are delighted to limit the size of the alliance. Finally, the manufacturer can select the appropriate retailer to boost its surplus, which has no effect on the surplus of the other retailers. The numerical examples indicate that the grand coalition is stable under the proposed allocation scheme.

  17. Search for Heavy Stable Charged Particles at $\\sqrt{s}$ = 13 TeV Utilizing a Multivariate Approach

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00375809

    Heavy stable charged particles (HSCPs) have been searched for at the Large Hadron Collider since its initial data taking in 2010. The search for heavy stable charged particles provide a means of directly probing the new physics realm, as they produce a detector signature unlike any particle discovered to date. The goal of this research is to investigate an idea that was introduced in the later stages of 2010-2012 data taking period. Rather than utilizing the current tight selection on the calculated particle mass the hypothesis is that by incorporating a multivariate approach, specif- ically an artificial neural network, the remaining selection criteria could be loosened allowing for a greater signal acceptance while maintaining acceptable background rejection via the multivariate discriminator from the artificial neural network. The increase in signal acceptance and retention or increase in background rejection increases the discovery potential for HSCPs and as a secondary objective calculates improved limit...

  18. Surgical approach for elastic stable intramedullary nail in pediatric radius shaft fracture

    DEFF Research Database (Denmark)

    Nørgaard, Sandra L.; Schødt Riber, Sara; Danielsson, Frederik B.

    2018-01-01

    . An electronic search of databases was performed. Titles of articles were screened, and abstracts and full text were read. Data were extracted in terms of demographics and complications. The dorsal approach had a 2.6% rate of extensor pollicis longus tendon rupture, whereas the lateral approach had a 2.9% rate...

  19. On stable exponential cosmological solutions with non-static volume factor in the Einstein-Gauss-Bonnet model

    International Nuclear Information System (INIS)

    Ivashchuk, V D; Ernazarov, K K

    2017-01-01

    A ( n + 1)-dimensional gravitational model with cosmological constant and Gauss-Bonnet term is studied. The ansatz with diagonal cosmological metrics is adopted and solutions with exponential dependence of scale factors: a i ∼ exp ( v i t ), i = 1, …, n , are considered. The stability analysis of the solutions with non-static volume factor is presented. We show that the solutions with v 1 = v 2 = v 3 = H > 0 and small enough variation of the effective gravitational constant G are stable if certain restriction on ( v i ) is obeyed. New examples of stable exponential solutions with zero variation of G in dimensions D = 1 + m + 2 with m > 2 are presented. (paper)

  20. Nitrogen Fate in a Phreatic Fluviokarst Watershed: a Stable Isotope, Sediment Tracing, and Numerical Modeling Approach

    Science.gov (United States)

    Husic, A.; Fox, J.; Ford, W. I., III; Agouridis, C.; Currens, J. C.; Taylor, C. J.

    2017-12-01

    Sediment tracing tools provide an insight into provenance, fate, and transport of sediment and, when coupled to stable isotopes, can elucidate in-stream biogeochemical processes. Particulate nitrogen fate in fluviokarst systems is a relatively unexplored area of research partially due to the complex hydrodynamics at play in karst systems. Karst topography includes turbulent conduits that transport groundwater and contaminants at speeds more typical of open channel flows than laminar Darcian flows. While it is accepted that karst hydro-geomorphology represents a hybrid surface-subsurface system for fluid, further investigation is needed to determine whether, and to what extent, karst systems behave like surface agricultural streams or porous media aquifers with respect to their role in nitrogen cycling. Our objective is to gain an understanding of in-conduit nitrogen processes and their effect on net nitrogen-exports from karst springs to larger waterbodies. The authors apply water, sediment, carbon, and nitrogen tracing techniques to analyze water for nitrate, sediment carbon and nitrogen, and stable sediment nitrogen isotope (δ15N). Thereafter, a new numerical model is formulated that: simulates dissolved inorganic nitrogen and sediment nitrogen transformations in the phreatic karst conduit; couples carbon turnover and nitrogen transformations in the model structure; and simulates the nitrogen stable isotope mass balance for the dissolved and sediment phases. Nitrogen tracing data results show a significant increase in δ15N of sediment nitrogen at the spring outlet relative to karst inputs indicating the potential for isotope fractionation during dissolved N uptake by bed sediments in the conduit and during denitrification within bed sediments. The new numerical modeling structure is then used to reproduce the data results and provide an estimate of the relative dominance of N uptake and denitrification within the surficial sediments of the karst conduit system

  1. Stable isotope approach to fission product element studies of soil-to-plant transfer and in vitro modelling of ruminant digestion using inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Robb, Paul; Owen, L.M.W.; Crews, H.M.

    1995-01-01

    A stable isotope approach has been used to investigate two aspects of the behaviour of fission product elements in the environment and food chains using inductively coupled plasma mass spectrometry (ICP-MS). Limits of detection (dry mass LODs) of 0.053 mg kg -1 for Sr, 0.011 mg kg -1 for Cs and 0.084 mg kg -1 for Ce were low enough to allow the determination of soil-to-plant transfer factors for soft fruit and the application of the approach to an in vitro model of ruminant digestion. The multi-element measurement capability of ICP-MS also permitted the analysis of selected nutrients, including zinc, in in vitro experiments. (author)

  2. Distribution tactics for success in turbulent versus stable environments: A complexity theory approach

    Directory of Open Access Journals (Sweden)

    Roger Bruce Mason

    2013-05-01

    Full Text Available This article proposes that the external environment influences the choice of distribution tactics. Since businesses and markets are complex adaptive systems, using complexity theory to understand such environments is necessary, but it has not been widely researched. A qualitative case method using in-depth interviews investigated four successful, versus less successful, companies in turbulent versus stable environments. The results tentatively confirmed that the more successful company, in a turbulent market, sees distribution activities as less important than other aspects of the marketing mix, but uses them to stabilise customer relationships and to maintain distribution processes. These findings can benefit marketers by emphasising a new way to consider place activities. How marketers can be assisted, and suggestions for further research, are provided.

  3. A New Modular Approach to Nanoassembly: Stable and Addressable DNA Nanoconstructs via Orthogonal Click Chemistries

    KAUST Repository

    Gerrard, Simon R.

    2012-10-23

    Thermodynamic instability is a problem when assembling and purifying complex DNA nanostructures formed by hybridization alone. To address this issue, we have used photochemical fixation and orthogonal copper-free, ring-strain-promoted, click chemistry for the synthesis of dimeric, trimeric, and oligomeric modular DNA scaffolds from cyclic, double-stranded, 80-mer DNA nanoconstructs. This particular combination of orthogonal click reactions was more effective for nanoassembly than others explored. The complex nanostructures are stable to heat and denaturation agents and can therefore be purified and characterized. They are addressable in a sequence-specific manner by triplex formation, and they can be reversibly and selectively deconstructed. Nanostructures utilizing this orthogonal, chemical fixation methodology can be used as building blocks for nanomachines and functional DNA nanoarchitectures. © 2012 American Chemical Society.

  4. Distribution tactics for success in turbulent versus stable environments: A complexity theory approach

    Directory of Open Access Journals (Sweden)

    Roger Bruce Mason

    2013-11-01

    Full Text Available This article proposes that the external environment influences the choice of distribution tactics. Since businesses and markets are complex adaptive systems, using complexity theory to understand such environments is necessary, but it has not been widely researched. A qualitative case method using in-depth interviews investigated four successful, versus less successful, companies in turbulent versus stable environments. The results tentatively confirmed that the more successful company, in a turbulent market, sees distribution activities as less important than other aspects of the marketing mix, but uses them to stabilise customer relationships and to maintain distribution processes. These findings can benefit marketers by emphasising a new way to consider place activities. How marketers can be assisted, and suggestions for further research, are provided.

  5. The influence factor analyses of non-stable combustion in the ignition process of gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, Jian-ping; Zhang, Shi-cheng; Jie, Tao; Cao, Feng; Chen, Xu-si; Li, Hang; Liu, Yong-sun [ShangHai Marine diesel Engine Research Institute, Shanghai (China)

    2013-07-01

    The pulverized coal gasification technology is large-scale carried out in China for more than 10 years, and more and more coal gasification technology, such as SCGP, GSP, GE, indigenous gasifier, have been widely used in China. Ignition process is non-stable combustion process, which is the key process in the operation of gasifier. In ignition process of pulverized coal gasifier, the average temperature and pressure will increase to high level (about 800 C and 1 MPa) from the normal condition. In this paper, the trial furnace experiment have been carried out to study the non-stable flow and combustion characteristics in gasifier. The variety of the temperature and the shape of the flame with the pressure growing have been analyzed. These results show that the average temperature is increasing gradually at atmosphere pressure, while the high temperature region locates 100 mm away from the head of the ignition burner with a spindly shape. As the pressure goes up, the shapes of the flame shorten apparently, while the distance between the high temperature region and the head of the start-up burner decreases. Thereby, it is possible that the head of the start-up-burner will burning-out by the high temperature flame. Therefore, the pressure will tremendously influence the combustion process in gasifier, where the flame will change shortly and unstably.

  6. Stable oscillations of a predator-prey probabilistic cellular automaton: a mean-field approach

    Energy Technology Data Exchange (ETDEWEB)

    Tome, Tania; Carvalho, Kelly C de [Instituto de FIsica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil)

    2007-10-26

    We analyze a probabilistic cellular automaton describing the dynamics of coexistence of a predator-prey system. The individuals of each species are localized over the sites of a lattice and the local stochastic updating rules are inspired by the processes of the Lotka-Volterra model. Two levels of mean-field approximations are set up. The simple approximation is equivalent to an extended patch model, a simple metapopulation model with patches colonized by prey, patches colonized by predators and empty patches. This approximation is capable of describing the limited available space for species occupancy. The pair approximation is moreover able to describe two types of coexistence of prey and predators: one where population densities are constant in time and another displaying self-sustained time oscillations of the population densities. The oscillations are associated with limit cycles and arise through a Hopf bifurcation. They are stable against changes in the initial conditions and, in this sense, they differ from the Lotka-Volterra cycles which depend on initial conditions. In this respect, the present model is biologically more realistic than the Lotka-Volterra model.

  7. Relationship between tolerance factor and temperature coefficient of permittivity of temperature-stable high permittivity BaTiO3–Bi(MeO3 compounds

    Directory of Open Access Journals (Sweden)

    Natthaphon Raengthon

    2016-03-01

    Full Text Available The temperature coefficient of permittivity (TCε of BaTiO3–Bi(MeO3 solid solutions were investigated. It was determined that as the tolerance factor was decreased with the addition of Bi(MeO3, the TCε shifted from large negative values to TCε values approaching zero. It is proposed that the different bonding nature of the dopant cation affects the magnitude and temperature stability of the permittivity. This study suggests that the relationship between tolerance factor and TCε can be used as a guide to design new dielectric compounds exhibiting temperature-stable high permittivity characteristics, which is similar to past research on perovskite and pyrochlore-based microwave dielectrics.

  8. A stable isotope approach and its application for identifying nitrate source and transformation process in water.

    Science.gov (United States)

    Xu, Shiguo; Kang, Pingping; Sun, Ya

    2016-01-01

    Nitrate contamination of water is a worldwide environmental problem. Recent studies have demonstrated that the nitrogen (N) and oxygen (O) isotopes of nitrate (NO3(-)) can be used to trace nitrogen dynamics including identifying nitrate sources and nitrogen transformation processes. This paper analyzes the current state of identifying nitrate sources and nitrogen transformation processes using N and O isotopes of nitrate. With regard to nitrate sources, δ(15)N-NO3(-) and δ(18)O-NO3(-) values typically vary between sources, allowing the sources to be isotopically fingerprinted. δ(15)N-NO3(-) is often effective at tracing NO(-)3 sources from areas with different land use. δ(18)O-NO3(-) is more useful to identify NO3(-) from atmospheric sources. Isotopic data can be combined with statistical mixing models to quantify the relative contributions of NO3(-) from multiple delineated sources. With regard to N transformation processes, N and O isotopes of nitrate can be used to decipher the degree of nitrogen transformation by such processes as nitrification, assimilation, and denitrification. In some cases, however, isotopic fractionation may alter the isotopic fingerprint associated with the delineated NO3(-) source(s). This problem may be addressed by combining the N and O isotopic data with other types of, including the concentration of selected conservative elements, e.g., chloride (Cl(-)), boron isotope (δ(11)B), and sulfur isotope (δ(35)S) data. Future studies should focus on improving stable isotope mixing models and furthering our understanding of isotopic fractionation by conducting laboratory and field experiments in different environments.

  9. General and simple approach for control cage and cylindrical mesopores, and thermal/hydrothermal stable frameworks.

    Science.gov (United States)

    El-Safty, Sherif A; Mizukami, Fujio; Hanaoka, Takaaki

    2005-05-19

    Highly ordered cage and cylindrical mesoporeous silica monoliths (HOM) with 2- and 3-dimensional (2D and 3D, respectively) structures, mesopore/micropore volumes, and thick-walled frameworks were successfully fabricated by instant direct templating of lyotropic phases of copolymer (EO(m)-PO(n)-EO(m)) surfactants. Large cage-like pores with uniform constriction sizes up to 10 nm and open cylindrical channel-like mesopores can be easily achieved by this simple and efficient synthesis design. Our results show that the cage-like pores could be fabricated at relatively lower copolymer concentrations used in the lyotropic phase domains at copolymer/TMOS ratios of 35 wt %. These ordered cage pore architectures underwent transition to open-cylindrical pores by increasing the copolymer concentration. High EO/PO block copolymers, in general, were crucially affected on the increase of the interior cavity sizes and on the stability of the cage mesopore characters. However, for F108 (EO(141)PO(44)EO(141)) systems, the fabrication of ordered and stable cage pore monoliths was achieved with significantly higher copolymer concentrations up to 90 wt %. Interestingly, the effective copolymer molecular nature was also observed in the ability to design various ordered mesophase geometries in large domain sizes. Our findings here show evidence that the synthetic strategy provides realistic control over a wide range of mesostructured phase geometries and their extended long-range ordering in the final replicas of the silica monolith frameworks. In addition, the HOM silica monoliths exhibited considerable structural stability against higher thermal temperature (up to 1000 degrees C) and longer hydrothermal treatment times under boiling water and steam. The remarkable structural findings of 3D frameworks, transparent monoliths, and micropores combined with large cage- and cylindrical-like mesopores are expected to find promising uses in materials chemistry.

  10. Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach.

    Science.gov (United States)

    McMahon, Kelton W; Thorrold, Simon R; Houghton, Leah A; Berumen, Michael L

    2016-03-01

    Coral reefs support spectacularly productive and diverse communities in tropical and sub-tropical waters throughout the world's oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column production, benthic primary production, and recycled detrital carbon (C). We coupled compound-specific stable C isotope ratio (δ(13)C) analyses with Bayesian mixing models to quantify C flow from primary producers to coral reef fishes across multiple feeding guilds and trophic positions in the Red Sea. Analyses of reef fishes with putative diets composed primarily of zooplankton (Amblyglyphidodon indicus), benthic macroalgae (Stegastes nigricans), reef-associated detritus (Ctenochaetus striatus), and coral tissue (Chaetodon trifascialis) confirmed that δ(13)C values of essential amino acids from all baseline C sources were both isotopically diagnostic and accurately recorded in consumer tissues. While all four source end-members contributed to the production of coral reef fishes in our study, a single-source end-member often dominated dietary C assimilation of a given species, even for highly mobile, generalist top predators. Microbially reworked detritus was an important secondary C source for most species. Seascape configuration played an important role in structuring resource utilization patterns. For instance, Lutjanus ehrenbergii showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13 % of dietary C) to a phytoplankton-based food web (72 ± 11 %) on oceanic reefs. Our work provides insights into the roles that diverse C sources play in the structure and function of coral reef ecosystems and illustrates a powerful fingerprinting method to develop and test nutritional frameworks for understanding resource utilization.

  11. Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach

    KAUST Repository

    McMahon, Kelton

    2015-11-21

    Coral reefs support spectacularly productive and diverse communities in tropical and sub-tropical waters throughout the world’s oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column production, benthic primary production, and recycled detrital carbon (C). We coupled compound-specific stable C isotope ratio (δ13C) analyses with Bayesian mixing models to quantify C flow from primary producers to coral reef fishes across multiple feeding guilds and trophic positions in the Red Sea. Analyses of reef fishes with putative diets composed primarily of zooplankton (Amblyglyphidodon indicus), benthic macroalgae (Stegastes nigricans), reef-associated detritus (Ctenochaetus striatus), and coral tissue (Chaetodon trifascialis) confirmed that δ13C values of essential amino acids from all baseline C sources were both isotopically diagnostic and accurately recorded in consumer tissues. While all four source end-members contributed to the production of coral reef fishes in our study, a single-source end-member often dominated dietary C assimilation of a given species, even for highly mobile, generalist top predators. Microbially reworked detritus was an important secondary C source for most species. Seascape configuration played an important role in structuring resource utilization patterns. For instance, Lutjanus ehrenbergii showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13 % of dietary C) to a phytoplankton-based food web (72 ± 11 %) on oceanic reefs. Our work provides insights into the roles that diverse C sources play in the structure and function of coral reef ecosystems and illustrates a powerful fingerprinting method to develop and test nutritional frameworks for understanding resource utilization.

  12. Toward a Secure and Stable Northern Mali: Approaches to Engaging Local Actors

    Science.gov (United States)

    2013-01-01

    Approaches to Engaging Local Actors 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) RAND Corporation,National Defense Research Institute,1776 Main Street, P.O...Box 2138,Santa Monica,CA,90407-2138 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR

  13. A Factorization Approach to the Linear Regulator Quadratic Cost Problem

    Science.gov (United States)

    Milman, M. H.

    1985-01-01

    A factorization approach to the linear regulator quadratic cost problem is developed. This approach makes some new connections between optimal control, factorization, Riccati equations and certain Wiener-Hopf operator equations. Applications of the theory to systems describable by evolution equations in Hilbert space and differential delay equations in Euclidean space are presented.

  14. Factors Affecting Mercury Stable Isotopic Distribution in Piscivorous Fish of the Laurentian Great Lakes.

    Science.gov (United States)

    Lepak, Ryan F; Janssen, Sarah E; Yin, Runsheng; Krabbenhoft, David P; Ogorek, Jacob M; DeWild, John F; Tate, Michael T; Holsen, Thomas M; Hurley, James P

    2018-03-06

    Identifying the sources of methylmercury (MeHg) and tracing the transformations of mercury (Hg) in the aquatic food web are important components of effective strategies for managing current and legacy Hg sources. In our previous work, we measured stable isotopes of Hg (δ 202 Hg, Δ 199 Hg, and Δ 200 Hg) in the Laurentian Great Lakes and estimated source contributions of Hg to bottom sediment. Here, we identify isotopically distinct Hg signatures for Great Lakes trout ( Salvelinus namaycush) and walleye ( Sander vitreus), driven by both food-web and water-quality characteristics. Fish contain high values for odd-isotope mass independent fractionation (MIF) with averages ranging from 2.50 (western Lake Erie) to 6.18‰ (Lake Superior) in Δ 199 Hg. The large range in odd-MIF reflects variability in the depth of the euphotic zone, where Hg is most likely incorporated into the food web. Even-isotope MIF (Δ 200 Hg), a potential tracer for Hg from precipitation, appears both disconnected from lake sedimentary sources and comparable in fish among the five lakes. We suggest that similar to the open ocean, water-column methylation also occurs in the Great Lakes, possibly transforming recently deposited atmospheric Hg deposition. We conclude that the degree of photochemical processing of Hg is controlled by phytoplankton uptake rather than by dissolved organic carbon quantity among lakes.

  15. The effect of environmental factors on stable isotopic composition of n-alkanes in Mediterranean olive oils

    Science.gov (United States)

    Pedentchouk, Nikolai; Mihailova, Alina; Abbado, Dimitri

    2014-05-01

    Traceability of the geographic origin of olive oils is an important issue from both commercial and health perspectives. This study evaluates the impact of environmental factors on stable C and H isotope compositions of n-alkanes in extra virgin olive oils from Croatia, France, Greece, Italy, Morocco, Portugal, Slovenia, and Spain. The data are used to investigate the applicability of stable isotope methodology for olive oil regional classification in the Mediterranean region. Analysis of stable C isotope composition of n-C29 alkane showed that extra virgin olive oils from Portugal and Spain have the most positive n-C29 alkane delta13C values. Conversely, olive oils from Slovenia, northern and central Italy are characterized by the most negative values. Overall, the n-C29 alkane delta13C values show a positive correlation with the mean air temperature during August-December and a negative correlation with the mean relative humidity during these months. Analysis of stable H isotope composition of n-C29 alkane revealed that the deltaD values are the most positive in olive oils from Greece and Morocco and the most negative in oils from northern Italy. The deltaD values of oils show significant correlation with all the analyses geographical parameters: the mean air temperature and relative humidity during August-December, the total amount of rainfall (the same months) and the annual deltaD values of precipitation. As predictor variables in the Categorical Data Analysis, the n-C29 alkane deltaD values show the most significant discriminative power, followed by the n-C29 alkane delta13C values. Overall, 93.4% of olive oil samples have been classified correctly into one of the production regions. Our findings suggest that an integrated analysis of C and H isotope compositions of n-alkanes extracted from extra virgin olive oil could become a useful tool for geographical provenancing of this highly popular food commodity.

  16. Learning Approaches, Demographic Factors to Predict Academic Outcomes

    Science.gov (United States)

    Nguyen, Tuan Minh

    2016-01-01

    Purpose: The purpose of this paper is to predict academic outcome in math and math-related subjects using learning approaches and demographic factors. Design/Methodology/Approach: ASSIST was used as the instrumentation to measure learning approaches. The study was conducted in the International University of Vietnam with 616 participants. An…

  17. Seeking a stable future: perspectives on population policy. The legal approach: women's rights as human rights.

    Science.gov (United States)

    Pine, R N

    1994-01-01

    As it has grappled with issues of population policy, the international community has emphasized that women's reproductive rights are human rights. Scholars have also acknowledged that the right to reproductive health care exists within the scope of international human rights treaties and conventions and that gender equality, nondiscrimination, and freedom from government interference in marriage and family life are also guaranteed. Further protections extend to counseling and health information and referral. The Programme of Action of the 1994 International Conference on Population and Development continues this trend by emphasizing the importance of human rights for attaining population and development objectives, calling on governments to focus their efforts on improving the quality of life for individuals, and endorsing the notion that reproductive rights are universal human rights. Reproductive health care options are also influenced by sovereign laws that restrict availability of contraception, sterilization, or abortion. However, universal rights and unrestricted access must be complemented by other factors controlled by domestic laws to guarantee reproductive choice. Such laws cover issues like marriage age, divorce, marital property, child support, maternity benefits, day care, sex discrimination, eligibility for insurance, confidentiality, spousal consent, rape, and sexual abuse. Countries must modify restrictive national laws and promote laws protecting women's rights.

  18. Risk factors for re-fracture in children with diaphyseal fracture of the forearm treated with elastic stable intramedullary nailing.

    Science.gov (United States)

    Rousset, Marie; Mansour, Mounira; Samba, Antoine; Pereira, Bruno; Canavese, Federico

    2016-02-01

    A retrospective study aims to investigate predisposing factors leading to re-fracture in patients with nails still in place and to identify potential correlations between nail size-to-medullary canal diameter ratio and re-fracture, working to the hypothesis that a higher ratio correlates with a higher risk of re-fracture. Rates of re-fracture with nail still in place after forearm elastic stable intramedullary nailing are higher in younger pediatric patients. Re-fractures occurred at a mean age of 6.7 years (range 5-8.7). While the role of body frame and bone medullary diameter remains unclear, there are grounds for adjusting treatment strategy for age, weight and bone medullary diameter to achieve effective outcome. History of previous forearm fracture and open treatment may also be further risk factors.

  19. Mechanically stable tuning fork sensor with high quality factor for the atomic force microscope.

    Science.gov (United States)

    Kim, Kwangyoon; Park, Jun-Young; Kim, K B; Lee, Naesung; Seo, Yongho

    2014-01-01

    A quartz tuning fork was used instead of cantilever as a force sensor for the atomic force microscope. A tungsten tip was made by electrochemical etching from a wire of 50 µm diameter. In order to have mechanical stability of the tuning fork, it was attached on an alumina plate. The tungsten tip was attached on the inside end of a prong of a tuning fork. The phase shift was used as a feedback signal to control the distance between the tip and sample, and the amplitude was kept constant using a lock-in amplifier and a homemade automatic gain controller. Due to the mechanical stability, the sensor shows a high quality factor (∼10(3)), and the image quality obtained with this sensor was equivalent to that of the cantilever-based AFM. © 2014 Wiley Periodicals, Inc.

  20. Boron compartmentation in roots of sunflower plants of different boron status: A study using the stable isotopes 10B and 11B adopting two independent approaches

    International Nuclear Information System (INIS)

    Pfeffer, H.; Dannel, F.; Roemheld, V.

    2001-01-01

    The intracellular compartmentation of boron (B) in roots of sunflower plants precultured with 100 μM B (high B) or 1 μM B (low B) was studied using two independent approaches. In the first approach, short-term efflux studies using the stable isotopes 11 B and 10 B were carried out. In roots of high B plants, the calculated concentrations of B (nmol g FW -1 ) were 52.6 in the cell wall, 7.5 in the vacuole, 27.1 in the cytosol and 48.0 in the free space. In roots of low B plants, the concentrations of B (nmol g FW -1 ) were 43.4 in the cell wall, 2.8 in the vacuole, 17.9 in the cytosol and almost zero in the free space. Although the B supply differed by a factor 100, the B concentrations in the cytosol and the vacuole of low B plants were 66 and 37% of the respective concentrations in high B plants. This suggests an additional role for B in plant metabolism, besides its function in the cell wall. In the second approach, root B pools (cell sap and water-insoluble residue) were determined for comparison, and found to be in good agreement with the results from the efflux study. (au)

  1. Dietary shift after 3600 cal yr BP and its influencing factors in northwestern China: Evidence from stable isotopes

    Science.gov (United States)

    Ma, Minmin; Dong, Guanghui; Jia, Xin; Wang, Hui; Cui, Yifu; Chen, Fahu

    2017-04-01

    :Human diets rely on natural resource availability and can reflect social and cultural values. When environments, societies, and cultures change, diets may also shift. This study traced the extent of dietary change and the factors influencing such change. Through stable carbon and nitrogen isotopic analysis of late Neolithic and early Bronze Age human and animal bone collagen, we found that significant shifts in human diets were closely associated with intercontinental cultural exchanges in Eurasia and climate change in northwestern China. The isotopic evidence indicated that human diets mainly consisted of C4 foodstuffs (presumably millet and/or animals fed with C4 foods) around 4000 calibrated years before the present (cal yr BP), corresponding to the flourishing of millet agriculture in the context of the optimal climate conditions of the mid-Holocene. Subsequently, more C3 foods (probably wheat, barley, and animals fed with C3 foods) were added to human diets post-3600 cal yr BP when the climate became cooler and drier. Such dietary variation is also consistent with the increasing intensity of long-distance exchange after 4000 cal yr BP. While many factors can lead to human dietary shifts (e.g. climate change, population growth, cultural factors, and human migration), climate may have been a key factor in Gansu and Qinghai.

  2. What are the risk factors for dislocation in primary total hip arthroplasty? A multicenter case-control study of 128 unstable and 438 stable hips.

    Science.gov (United States)

    Fessy, M H; Putman, S; Viste, A; Isida, R; Ramdane, N; Ferreira, A; Leglise, A; Rubens-Duval, B; Bonin, N; Bonnomet, F; Combes, A; Boisgard, S; Mainard, D; Leclercq, S; Migaud, H

    2017-09-01

    Dislocation after total hip arthroplasty (THA) is a leading reason for surgical revision. The risk factors for dislocation are controversial, particularly those related to the patient and to the surgical procedure itself. The differences in opinion on the impact of these factors stem from the fact they are often evaluated using retrospective studies or in limited patient populations. This led us to carry out a prospective case-control study on a large population to determine: 1) the risk factors for dislocation after THA, 2) the features of these dislocations, and 3) the contribution of patient-related factors and surgery-related factors. Risk factors for dislocation related to the patient and procedure can be identified using a large case-control study. A multicenter, prospective case-control study was performed between January 1 and December 31, 2013. Four patients with stable THAs were matched to each patient with a dislocated THA. This led to 566 primary THA cases being included: 128 unstable, 438 stable. The primary matching factors were sex, age, initial diagnosis, surgical approach, implantation date and type of implants (bearing size, standard or dual-mobility cup). The patients with unstable THAs were 67±12 [37-73]years old on average; there were 61 women (48%) and 67 men (52%). Hip osteoarthritis (OA) was the main reason for the THA procedure in 71% (91/128) of the unstable group. The dislocation was posterior in 84 cases and anterior in 44 cases. The dislocation occurred within 3 months of the primary surgery in 48 cases (38%), 3 to 12 months after in 23 cases (18%), 1 to 5years after in 20 cases (16%), 5 to 10years after in 17 cases (13%) and more than 10years later in 20 cases. The dislocation recurred within 6 months of the initial dislocation in 23 of the 128 cases (18%). The risk factors for instability were a high ASA score with an odds ratio (OR) of 1.93 (95% CI: 1.4-2.6), neurological disability (cognitive, motor or psychiatric disorders) with

  3. Effect of Dietary Intake of Stable Iodine on Dose-per-unit-intake Factors for 99Tc

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Daniel J.

    2003-09-30

    of stable iodine in the diet on the dose per unit intake factors for 99Tc without developing an improved biokinetic model for technetium. Specific experiments should be designed to quantitatively evaluate 99TcO4? metabolism, excretion, and secretion, as well as to evaluate its chemical toxicity It is recommended that the ICRP reexamine its biokinetics models for Tc based on nuclear medicine data that have accumulated over the years. In particular, the ICRP ignores the lactation pathway, the enhanced concentration of Tc in breast and breast milk, and enhanced concentration of Tc (and I) in the salivary glands as well as in the thyroid. The ICRP should also explicitly incorporate the effect of stable iodine in the diet into both its models for iodine and technetium. The effect of concentration of Tc in breast milk needs further study for dosimetric implications to nursing infants whose mothers may ingest 99TcO4? from groundwater sources. The ICRP should also investigate the possibility of enhanced concentration of both I and Tc in the non-lactating female breast. To do these re-evaluations of biokinetic models, new experiments designed specifically to evaluate these questions concerning the biokinetics of Tc and I are needed.

  4. Evidence of chronic anthropogenic nutrient within coastal lagoon reefs adjacent to urban and tourism centers, Kenya: A stable isotope approach.

    Science.gov (United States)

    Mwaura, Jelvas; Umezawa, Yu; Nakamura, Takashi; Kamau, Joseph

    2017-06-30

    The source of anthropogenic nutrient and its spatial extent in three fringing reefs with differing human population gradients in Kenya were investigated using stable isotope approaches. Nutrient concentrations and nitrate-δ 15 N in seepage water indicated that population density and tourism contributed greatly to the extent of nutrient loading to adjacent reefs. Although water-column nutrient analyses did not show any significant difference among the reefs, higher δ 15 N and N contents in macrophytes showed terrestrial nutrients affected primary producers in onshore areas in Nyali and Bamburi reefs, but were mitigated by offshore water intrusion especially at Nyali. On the offshore reef flat, where the same species of macroalgae were not available, complementary use of δ 15 N in sedimentary organic matter suggested inputs of nutrients originated from the urban city of Mombasa. If population increases in the future, nutrient conditions in the shallower reef, Vipingo, may be dramatically degraded due to lower water exchange ratio. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Factors controlling stable isotope composition of precipitation in arid conditions: an observation network in the Tianshan Mountains, central Asia

    Directory of Open Access Journals (Sweden)

    Shengjie Wang

    2016-02-01

    Full Text Available Approximately one-third of the Earth's arid areas are distributed across central Asia. The stable isotope composition of precipitation in this region is affected by its aridity, therefore subject to high evaporation and low precipitation amount. To investigate the factors controlling stable water isotopes in precipitation in arid central Asia, an observation network was established around the Tianshan Mountains in 2012. Based on the 1052 event-based precipitation samples collected at 23 stations during 2012–2013, the spatial distribution and seasonal variation of δD and δ18O in precipitation were investigated. The values of δD and δ18O are relatively more enriched in the rainfall dominant summer months (from April to October and depleted in the drier winter months (from November to March with low D-excess due to subcloud evaporation observed at many of the driest low elevation stations. The local meteoric water line (LMWL was calculated to be δD=7.36δ18O – 0.50 (r2=0.97, p<0.01 based on the event-based samples, and δD=7.60δ18O+2.66 (r2=0.98, p<0.01 based on the monthly precipitation-weighted values. In winter, the data indicate an isotopic rain shadow effect whereby rainout leads to depletion of precipitation in the most arid region to the south of the Tianshan Mountains. The values of δ18O significantly correlate with air temperature for each station, and the best-fit equation is established as δ18O=0.78T – 16.01 (r2=0.73, p<0.01. Using daily air temperature and precipitation derived from a 0.5° (latitude×0.5° (longitude gridded data set, an isoscape of δ18O in precipitation was produced based on this observed temperature effect.

  6. Factors associated with health-related quality of life in stable ambulatory congestive heart failure patients: Systematic review.

    Science.gov (United States)

    Baert, Anneleen; De Smedt, Delphine; De Sutter, Johan; De Bacquer, Dirk; Puddu, Paolo Emilio; Clays, Els; Pardaens, Sofie

    2018-03-01

    Background Since improved treatment of congestive heart failure has resulted in decreased mortality and hospitalisation rates, increasing self-perceived health-related quality of life (HRQoL) has become a major goal of congestive heart failure treatment. However, an overview on predictieve factors of HRQoL is currently lacking in literature. Purpose The aim of this study was to identify key factors associated with HRQoL in stable ambulatory patients with congestive heart failure. Methods A systematic review was performed. MEDLINE, Web of Science and Embase were searched for the following combination of terms: heart failure, quality of life, health perception or functional status between the period 2000 and February 2017. Literature screening was done by two independent reviewers. Results Thirty-five studies out of 8374 titles were included for quality appraisal, of which 29 were selected for further data extraction. Four distinct categories grouping different types of variables were identified: socio-demographic characteristics, clinical characteristics, health and health behaviour, and care provider characteristics. Within the above-mentioned categories the presence of depressive symptoms was most consistently related to a worse HRQoL, followed by a higher New York Heart Association functional class, younger age and female gender. Conclusion Through a systematic literature search, factors associated with HRQoL among congestive heart failure patients were investigated. Age, gender, New York Heart Association functional class and depressive symptoms are the most consistent variables explaining the variance in HRQoL in patients with congestive heart failure. These findings are partly in line with previous research on predictors for hard endpoints in patients with congestive heart failure.

  7. A Computational Drug Repositioning Approach for Targeting Oncogenic Transcription Factors

    OpenAIRE

    Gayvert, Kaitlyn; Dardenne, Etienne; Cheung, Cynthia; Boland, Mary Regina; Lorberbaum, Tal; Wanjala, Jackline; Chen, Yu; Rubin, Mark; Tatonetti, Nicholas P.; Rickman, David; Elemento, Olivier

    2016-01-01

    Mutations in transcription factors (TFs) genes are frequently observed in tumors, often leading to aberrant transcriptional activity. Unfortunately, TFs are often considered undruggable due to the absence of targetable enzymatic activity. To address this problem, we developed CRAFTT, a Computational drug-Repositioning Approach For Targeting Transcription factor activity. CRAFTT combines ChIP-seq with drug-induced expression profiling to identify small molecules that can specifically perturb T...

  8. Factorization approach to superintegrable systems: Formalism and applications

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, Á., E-mail: angelb@ubu.es; Herranz, F. J., E-mail: fjherranz@ubu.es [Universidad de Burgos, Departamento de Física (Spain); Kuru, Ş., E-mail: kuru@science.ankara.edu.tr [Ankara University, Department of Physics, Faculty of Science (Turkey); Negro, J., E-mail: jnegro@fta.uva.es [Universidad de Valladolid, Departamento de Física Teórica, Atómica y Óptica (Spain)

    2017-03-15

    The factorization technique for superintegrable Hamiltonian systems is revisited and applied in order to obtain additional (higher-order) constants of the motion. In particular, the factorization approach to the classical anisotropic oscillator on the Euclidean plane is reviewed, and new classical (super) integrable anisotropic oscillators on the sphere are constructed. The Tremblay–Turbiner–Winternitz system on the Euclidean plane is also studied from this viewpoint.

  9. Towards development of stable formulations of a live attenuated bacterial vaccine: a preformulation study facilitated by a biophysical approach.

    Science.gov (United States)

    Zeng, Yuhong; Fan, Haihong; Chiueh, Gary; Pham, Binh; Martin, Russ; Lechuga-Ballesteros, David; Truong, Vu L; Joshi, Sangeeta B; Middaugh, C Russell

    2009-05-01

    Development of optimal formulation conditions stabilizing live attenuated bacterial vaccines is impeded by traditional methods used for viability measurement. To facilitate preformulation studies of such vaccines, spectroscopic techniques capable of providing real-time and high throughput information have been employed to obtain a global stability profile for a live attenuated Ty21a bacterial typhoid vaccine over a wide range of pH (4 to 8) and temperature (10 to 85 degrees C). Using the data obtained from fluorescence and circular dichroism techniques, an empirical phase diagram (EPD) has been subsequently constructed, which suggests that Ty21a cells exist in at least four apparent physical phases related to different viability states, with the most stable phase at pH 6 and 7 at temperatures below 30 degrees C. A slightly basic pH (pH 8) appears to decrease the fluidity of the cell membrane, whereas acidic pH conditions are detrimental to membrane integrity over the entire temperature range. Based on the above stability profile, a fluorescence-based high throughput screening assay has been developed to test the stabilizing effects of various compounds at different concentrations. Amongst other promising stabilizers, 10% sucrose and 0.15 M glutamic acid display the greatest protective effects, with an increase of about 10 degrees C in the transition temperature of Ty21a cells. Preliminary studies have also been performed on foam dried formulations as an alternative approach to further stabilize Ty21a cells. The data show that 10% sucrose and trehalose both increase the in-process and storage stabilities of the cells.

  10. A randomized study of coconut oil versus sunflower oil on cardiovascular risk factors in patients with stable coronary heart disease.

    Science.gov (United States)

    Vijayakumar, Maniyal; Vasudevan, D M; Sundaram, K R; Krishnan, Sajitha; Vaidyanathan, Kannan; Nandakumar, Sandya; Chandrasekhar, Rajiv; Mathew, Navin

    2016-01-01

    Coronary artery disease (CAD) and its pathological atherosclerotic process are closely related to lipids. Lipids levels are in turn influenced by dietary oils and fats. Saturated fatty acids increase the risk for atherosclerosis by increasing the cholesterol level. This study was conducted to investigate the impact of cooking oil media (coconut oil and sunflower oil) on lipid profile, antioxidant mechanism, and endothelial function in patients with established CAD. In a single center randomized study in India, patients with stable CAD on standard medical care were assigned to receive coconut oil (Group I) or sunflower oil (Group II) as cooking media for 2 years. Anthropometric measurements, serum, lipids, Lipoprotein a, apo B/A-1 ratio, antioxidants, flow-mediated vasodilation, and cardiovascular events were assessed at 3 months, 6 months, 1 year, and 2 years. Hundred patients in each arm completed 2 years with 98% follow-up. There was no statistically significant difference in the anthropometric, biochemical, vascular function, and in cardiovascular events after 2 years. Coconut oil even though rich in saturated fatty acids in comparison to sunflower oil when used as cooking oil media over a period of 2 years did not change the lipid-related cardiovascular risk factors and events in those receiving standard medical care. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  11. Putative new heat-stable cytotoxic and enterotoxic factors in culture supernatant of Escherichia coli isolated from drinking water

    Directory of Open Access Journals (Sweden)

    DA Ribeiro

    2011-01-01

    Full Text Available Enteric infections caused by the ingestion of contaminated water, especially by Escherichia coli, are important to define the virulence properties of these bacteria. Due to frequent infantile diarrhea in the city of Ouro Preto, Minas Gerais state, Brazil, the phenotypic and genotypic diarrheagenic properties of E. coli isolated from drinking water were studied. The culture supernatants of 39 (40% among a total of 97 E. coli isolates from drinking water were positive by suckling mouse assay and induced cytotoxic effects on Vero cells. The enterotoxic and cytotoxic activities were present in the fraction with less than 10 kDa and were not lost when heated up to 60°C and 100°C for 30 minutes. PCR assays showed that among these 39 Vero cytotoxigenic E. coli, four (10.2% were positive for ST II (estB and two (5% positive for αHly (hlyA. Gene amplification of SLT (stx 1, stx 2, ST I (estA, LT (eltI, eltII, EAST1 (astA, EHly (enhly and plasmid-encoded enterotoxin (pet were not observed. This heat-stable cytotoxic enterotoxin of E. coli is probably a new putative diarrheagenic virulence factor, as a toxin presenting these characteristics has not yet been described.

  12. Stable isotope labeling by amino acids in cell culture, SILAC, as a simple and accurate approach to expression proteomics

    DEFF Research Database (Denmark)

    Ong, S.E.; Blagoev, B.; Kratchmarova, I.

    2002-01-01

    Quantitative proteomics has traditionally been performed by two-dimensional gel electrophoresis, but recently, mass spectrometric methods based on stable isotope quantitation have shown great promise for the simultaneous and automated identification and quantitation of complex protein mixtures. H...

  13. Safer approaches and landings: A multivariate analysis of critical factors

    Science.gov (United States)

    Heinrich, Durwood J.

    The approach-and-landing phases of flight represent 27% of mission time while resulting in 61 of the accidents and 39% of the fatalities. The landing phase itself represents only 1% of flight time but claims 45% of the accidents. Inadequate crew situation awareness (SA), crew resource management (CRM), and crew decision-making (DM) have been implicated in 51%, 63%, and 73% respectively of these accidents. The human factors constructs of SA, CRM, and DM were explored; a comprehensive definition of SA was proposed; and a "proactive defense" safety strategy was recommended. Data from a 1997 analysis of worldwide fatal accidents by the Flight Safety Foundation (FSF) Approach-and-Landing Accident Reduction (ALAR) Task Force was used to isolate crew- and weather-related causal factors that lead to approach-and-landing accidents (ALAs). Logistic regression and decision tree analysis were used on samplings of NASA's Aviation Safety Reporting System (ASRS) incident records ("near misses") and the National Transportation Safety Board's (NTSB) accident reports to examine hypotheses regarding factors and factor combinations that can dramatically increase the opportunity for accidents. An effective scale of risk factors was introduced for use by crews to proactively counter safety-related error-chain situations.

  14. Sea level rise and the geoid: factor analysis approach

    Directory of Open Access Journals (Sweden)

    Alexey Sadovski

    2013-08-01

    Full Text Available Sea levels are rising around the world, and this is a particular concern along most of the coasts of the United States. A 1989 EPA report shows that sea levels rose 5-6 inches more than the global average along the Mid-Atlantic and Gulf Coasts in the last century. The main reason for this is coastal land subsidence. This sea level rise is considered more as relative sea level rise than global sea level rise. Thus, instead of studying sea level rise globally, this paper describes a statistical approach by using factor analysis of regional sea level rates of change. Unlike physical models and semi-empirical models that attempt to approach how much and how fast sea levels are changing, this methodology allows for a discussion of the factor(s that statistically affects sea level rates of change, and seeks patterns to explain spatial correlations.

  15. Factors determining early internationalization of entrepreneurial SMEs: Theoretical approach

    Directory of Open Access Journals (Sweden)

    Agne Matiusinaite

    2015-12-01

    Full Text Available Purpose – This study extends the scientific discussion of early internationalization of SMEs. The main purpose of this paper – to develop a theoretical framework to investigate factors determining early internationalization of international new ventures. Design/methodology/approach – The conceptual framework is built on the analysis and synthesis of scientific literature. Findings – This paper presents different factors, which determine early internationalization of international new ventures. These factors are divided to entrepreneurial, organizational and contextual factors. We argue that early internationalization of international new ventures is defined by entrepreneurial characteristics and previous experience of the entrepreneur, opportunities recognition and exploitation, risk tolerance, specific of the organization, involvement into networks and contextual factors. Study proved that only interaction between factors and categories has an effect for business development and successful implementation of early internationalization. Research limitations/implications – The research was conducted on the theoretical basis of scientific literature. The future studies could include a practical confirmation or denial of such allocation of factors. Originality/value – The originality of this study lies in the finding that factor itself has limited effect to early internationalization. Only the interoperability of categories and factors gives a positive impact on early internationalization of entrepreneurial SMEs.

  16. Standardized approach for developing probabilistic exposure factor distributions

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy L.; McKone, Thomas E.; Sohn, Michael D.

    2003-03-01

    The effectiveness of a probabilistic risk assessment (PRA) depends critically on the quality of input information that is available to the risk assessor and specifically on the probabilistic exposure factor distributions that are developed and used in the exposure and risk models. Deriving probabilistic distributions for model inputs can be time consuming and subjective. The absence of a standard approach for developing these distributions can result in PRAs that are inconsistent and difficult to review by regulatory agencies. We present an approach that reduces subjectivity in the distribution development process without limiting the flexibility needed to prepare relevant PRAs. The approach requires two steps. First, we analyze data pooled at a population scale to (1) identify the most robust demographic variables within the population for a given exposure factor, (2) partition the population data into subsets based on these variables, and (3) construct archetypal distributions for each subpopulation. Second, we sample from these archetypal distributions according to site- or scenario-specific conditions to simulate exposure factor values and use these values to construct the scenario-specific input distribution. It is envisaged that the archetypal distributions from step 1 will be generally applicable so risk assessors will not have to repeatedly collect and analyze raw data for each new assessment. We demonstrate the approach for two commonly used exposure factors--body weight (BW) and exposure duration (ED)--using data for the U.S. population. For these factors we provide a first set of subpopulation based archetypal distributions along with methodology for using these distributions to construct relevant scenario-specific probabilistic exposure factor distributions.

  17. Positional enrichment by proton analysis (PEPA). A one-dimensional {sup 1}H-NMR approach for {sup 13}C stable isotope tracer studies in metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Vinaixa, Maria; Yanes, Oscar [Department of Electronic Engineering-Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Rodriguez, Miguel A.; Capellades, Jordi [Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Aivio, Suvi; Stracker, Travis H. [Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (Spain); Gomez, Josep; Canyellas, Nicolau [Department of Electronic Engineering-, Universitat Rovira i Virgili, Tarragona (Spain)

    2017-03-20

    A novel metabolomics approach for NMR-based stable isotope tracer studies called PEPA is presented, and its performance validated using human cancer cells. PEPA detects the position of carbon label in isotopically enriched metabolites and quantifies fractional enrichment by indirect determination of {sup 13}C-satellite peaks using 1D-{sup 1}H-NMR spectra. In comparison with {sup 13}C-NMR, TOCSY and HSQC, PEPA improves sensitivity, accelerates the elucidation of {sup 13}C positions in labeled metabolites and the quantification of the percentage of stable isotope enrichment. Altogether, PEPA provides a novel framework for extending the high-throughput of {sup 1}H-NMR metabolic profiling to stable isotope tracing in metabolomics, facilitating and complementing the information derived from 2D-NMR experiments and expanding the range of isotopically enriched metabolites detected in cellular extracts. (copyright 2017 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  18. Influence of environmental factors on dissolved nitrate stable isotopes under denitrifying conditions - carbon sources and water isotopes

    Science.gov (United States)

    Wunderlich, A.; Meckenstock, R.; Einsiedl, F.

    2012-04-01

    Stable isotopes in dissolved nitrate are regularly used to identify sources of nitrate contamination in aquifers and water bodies. A dual isotope plot of 15N and 18O in nitrate can provide good evidence of the origin of such pollution as various sources have different isotopic signatures. Microbial denitrification changes both isotopic values by removing nitrate with lighter isotopes first, thereby increasing δ18O as well as δ15N. This change can distort the determination of sources but also has the potential to be used to identify and quantify microbial denitrification. Previous studies found a wide range of enrichment factors (ɛ) that did not allow conclusions towards the extent of microbial denitrification. However, it was found that during denitrification at each respective field site or laboratory experiment, there was a constant ratio in increase of the values of δ18O in relation to δ15N. That ratio was, however, not constant across field sites and the values published range from below 0.5 to more than 1.0. The reasons for these variations in enrichment factors and relative enrichment of oxygen compared to nitrogen are yet unknown. We conducted microcosm experiments with three different bacterial species to elucidate possible influences of environmental factors on these parameters. As a result we conclude that the type of carbon source available to denitrifying bacteria can play a role in the value of the enrichment factors, but not in the relative enrichment of the two isotopes. Specifically we found that complex hydrocarbons (toluene, benzoate) produce significantly different enrichment factors in nitrate than a simple hydrocarbon substrate (acetate). The relative enrichment of δ18O compared to δ15N was 0.86. We hypothesise that this influence is based on a variation in process kinetics of cross-membrane nitrate transport in relation to intracellular nitrate reduction. The core of the hypothesis is that nitrate transport into the cell becomes rate

  19. Possible Food Sources of Macrozoobenthos in the Manko Mangrove Ecosystem, Okinawa (Japan): A Stable Isotope Analysis Approach

    Science.gov (United States)

    Wardiatno, Yusli; Mardiansyah; Prartono, Tri; Tsuchiya, Makoto

    2015-01-01

    Identifying potential food sources in mangrove ecosystems is complex because of the multifarious inputs from both land and sea. This study, which was conducted in the Manko mangrove ecosystem of Okinawa, Japan, determined the composition of the stable isotopes δ13C and δ15N in primary producers and macrozoobenthos to estimate the potential food sources assimilated and to elucidate the target trophic levels of the macrozoobenthos. We measured the two stable isotope signatures of three gastropods (Cerithidea sp., Cassidula mustelina, Peronia verruculata), two crabs (Grapsidae sp., Uca sp.), mangrove tree (Kandelia candel) leaves, and sediment from the mangrove ecosystem. The respective carbon and nitrogen isotope signature results were as follows: −22.4‰ and 8.6‰ for Cerithidea sp., −25.06‰ and 8‰ for C. mustelina, −22.58‰ and 8‰ for P. verruculata, −24.3‰ and 10.6‰ for unidentified Grapsidae, −21.87 ‰ and 11.5 ‰ for Uca sp., −29.81‰ and 11‰ for K. candel, and −24.23‰ and 7.2‰ for the sediment. The stable isotope assimilation signatures of the macrozoobenthos indicated sediment as their food source. Considering the trophic levels, the stable isotope values may also indicate that the five macrozoobenthos species were secondary or higher consumers. PMID:26019747

  20. A State Space Approach to Canonical Factorization with Applications

    CERN Document Server

    Bart, Harm; Kaashoek, MA; Ran, Andre CM

    2010-01-01

    The present book deals with canonical factorization of matrix and operator functions that appear in state space form or that can be transformed into such a form. A unified geometric approach is used. The main results are all expressed explicitly in terms of matrices or operators, which are parameters of the state space representation. The applications concern different classes of convolution equations. A large part the book deals with rational matrix functions only.

  1. A Factor Graph Approach to Automated GO Annotation.

    Directory of Open Access Journals (Sweden)

    Flavio E Spetale

    Full Text Available As volume of genomic data grows, computational methods become essential for providing a first glimpse onto gene annotations. Automated Gene Ontology (GO annotation methods based on hierarchical ensemble classification techniques are particularly interesting when interpretability of annotation results is a main concern. In these methods, raw GO-term predictions computed by base binary classifiers are leveraged by checking the consistency of predefined GO relationships. Both formal leveraging strategies, with main focus on annotation precision, and heuristic alternatives, with main focus on scalability issues, have been described in literature. In this contribution, a factor graph approach to the hierarchical ensemble formulation of the automated GO annotation problem is presented. In this formal framework, a core factor graph is first built based on the GO structure and then enriched to take into account the noisy nature of GO-term predictions. Hence, starting from raw GO-term predictions, an iterative message passing algorithm between nodes of the factor graph is used to compute marginal probabilities of target GO-terms. Evaluations on Saccharomyces cerevisiae, Arabidopsis thaliana and Drosophila melanogaster protein sequences from the GO Molecular Function domain showed significant improvements over competing approaches, even when protein sequences were naively characterized by their physicochemical and secondary structure properties or when loose noisy annotation datasets were considered. Based on these promising results and using Arabidopsis thaliana annotation data, we extend our approach to the identification of most promising molecular function annotations for a set of proteins of unknown function in Solanum lycopersicum.

  2. Configurationally stable, enantioenriched organometallic nucleophiles in stereospecific Pd-catalyzed cross-coupling reactions: an alternative approach to asymmetric synthesis

    Science.gov (United States)

    Wang, Chao-Yuan; Derosa, Joseph

    2015-01-01

    Several research groups have recently developed methods to employ configurationally stable, enantioenriched organometallic nucleophiles in stereospecific Pd-catalyzed cross-coupling reactions. By establishing the absolute configuration of a chiral alkyltin or alkylboron nucleophile prior to its use in cross-coupling reactions, new stereogenic centers may be rapidly and reliably generated with preservation of the known initial stereochemistry. While this area of research is still in its infancy, such stereospecific cross-coupling reactions may emerge as simple, general methods to access diverse, optically active products from common enantioenriched organometallic building blocks. This minireview highlights recent progress towards the development of general, stereospecific Pd-catalyzed cross-coupling reactions using configurationally stable organometallic nucleophiles. PMID:26388985

  3. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  4. Osteoporosis in primary care: an opportunity to approach risk factors

    Directory of Open Access Journals (Sweden)

    Angra Larissa Durans Costa

    2016-04-01

    Full Text Available ABSTRACT Introduction: Climacteric women are susceptible to a number of changes, among them osteoporosis. Osteoporosis is a disease characterized by low bone mass and susceptibility to fracture. Currently, this disease is a public health issue, being necessary to recognize its risk factors. Objectives: Identify risk factors related to osteoporosis in women attending Propis/Proex/UFMA, tracing a socio-demographic characterization and considering community lifestyles. Material and methods: This is a transversal retrospective clinical with a quantitative approach study conducted between March and June 2013 in São Luís (MA with 107 women treated at the Programa de Práticas de Integralidade em Saúde (Propis - Integrality Health Practice Program. The study was approved by the University Hospital Ethics Committee of UFMA under opinion no. 362/07. Data were tabulated and analyzed in the epidemiological Epi-Info® software, version 3.4.1. Results: The brown color was predominant, consensual relationships proved to be a protective factor and low education was a risk factor. The average age of the group with menopause was 54.1 years and without menopause was 31.3 years (p < 0.0001. The average age of menopause was 43.7 years. The irregular menstrual cycle was a protective factor. The average number of pregnancies was 4.56 for the group with menopause and 2.45 for the group without menopause, with most births occurring normally (p < 0.0001. Smoking, physical inactivity and caffeine intake were risk factors, while the absence of alcoholism and of soda intake were protective factors for the disease. Conclusion: The patients followed the socioeconomic and demographic profile of Maranhão. Most had menarche and menopause in appropriate periods, showed no positive family history of osteoporosis, did not usually drink alcohol, were sedentary and the caffeine intake was high.

  5. Osteoporosis in primary care: an opportunity to approach risk factors.

    Science.gov (United States)

    Costa, Angra Larissa Durans; da Silva, Marcos Antonio Custódio Neto; Brito, Luciane Maria Oliveira; Nascimento, Anna Cyntia Brandão; do Carmo Lacerda Barbosa, Maria; Batista, José Eduardo; de Barros Bezerra, Geusa Felipa; De Castro Viana, Graça Maria; Filho, Walbert Edson Muniz; Vidal, Flávia Castello Branco; Nascimento, Maria do Desterro Soares Brandão

    2016-01-01

    Climacteric women are susceptible to a number of changes, among them osteoporosis. Osteoporosis is a disease characterized by low bone mass and susceptibility to fracture. Currently, this disease is a public health issue, being necessary to recognize its risk factors. Identify risk factors related to osteoporosis in women attending PROPIS/PROEX/UFMA, tracing a socio-demographic characterization and considering community lifestyles. This is a transversal retrospective clinical with a quantitative approach study conducted between March and June 2013 in São Luís-MA with 107 women treated at the Programa de Práticas de Integralidade em Saúde (PROPIS - Integrality Health Practice Program). The study was approved by the University Hospital Ethics Committee of UFMA under opinion no. 362/07. Data were tabulated and analyzed in the epidemiological Epi-Info(®) software, version 3.4.1. The brown color was predominant, consensual relationships proved to be a protective factor and low education was a risk factor. The average age of the group with menopause was 54.1 years and without menopause was 31.3 years (p<0.0001). The average age of menopause was 43.7 years. The irregular menstrual cycle was a protective factor. The average number of pregnancies was 4.56 for the group with menopause and 2.45 for the group without menopause, with most births occurring normally (p<0.0001). Smoking, physical inactivity and caffeine intake were risk factors, while the absence of alcoholism and of soda intake were protective factors for the disease. The patients followed the socioeconomic and demographic profile of Maranhão. Most had menarche and menopause in appropriate periods, showed no positive family history of osteoporosis, did not usually drink alcohol, were sedentary and the caffeine intake was high. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

  6. A Sensitivity Analysis Approach to Identify Key Environmental Performance Factors

    Directory of Open Access Journals (Sweden)

    Xi Yu

    2014-01-01

    Full Text Available Life cycle assessment (LCA is widely used in design phase to reduce the product’s environmental impacts through the whole product life cycle (PLC during the last two decades. The traditional LCA is restricted to assessing the environmental impacts of a product and the results cannot reflect the effects of changes within the life cycle. In order to improve the quality of ecodesign, it is a growing need to develop an approach which can reflect the changes between the design parameters and product’s environmental impacts. A sensitivity analysis approach based on LCA and ecodesign is proposed in this paper. The key environmental performance factors which have significant influence on the products’ environmental impacts can be identified by analyzing the relationship between environmental impacts and the design parameters. Users without much environmental knowledge can use this approach to determine which design parameter should be first considered when (redesigning a product. A printed circuit board (PCB case study is conducted; eight design parameters are chosen to be analyzed by our approach. The result shows that the carbon dioxide emission during the PCB manufacture is highly sensitive to the area of PCB panel.

  7. Stable isotope labeling by amino acids in cell culture, SILAC, as a simple and accurate approach to expression proteomics

    DEFF Research Database (Denmark)

    Ong, S.E.; Blagoev, B.; Kratchmarova, I.

    2002-01-01

    -radioactive, isotopically labeled form of that amino acid, in this case deuterated leucine (Leu-d3). We find that growth of cells maintained in these media is no different from growth in normal media as evidenced by cell morphology, doubling time, and ability to differentiate. Complete incorporation of Leu-d3 occurred....... Here we describe a method, termed SILAC, for stable isotope labeling by amino acids in cell culture, for the in vivo incorporation of specific amino acids into all mammalian proteins. Mammalian cell lines are grown in media lacking a standard essential amino acid but supplemented with a non...

  8. Finding the Stable Structures of WxN1-x with an ab-initio High-Throughput Approach

    Science.gov (United States)

    2014-03-13

    properties must be energetically stable against decomposition into other compounds. This stability can only be found after the determination of the...polarized. However, in every structure the self-consistent magnetic moment was negligible, and the final calculations were all done assuming no moment. The...of NaCl) we looked at all 255 combinations. We found 34 unique structures, including NbO itself, CsCl, S3U4, ReO3,[59] cubic perovskite (with formula

  9. A Factor Analysis Approach for Clustering Patient Reported Outcomes.

    Science.gov (United States)

    Oh, Jung Hun; Thor, Maria; Olsson, Caroline; Skokic, Viktor; Jörnsten, Rebecka; Alsadius, David; Pettersson, Niclas; Steineck, Gunnar; Deasy, Joseph O

    2016-10-17

    In the field of radiation oncology, the use of extensive patient reported outcomes is increasingly common to measure adverse side effects after radiotherapy in cancer patients. Factor analysis has the potential to identify an optimal number of latent factors (i.e., symptom groups). However, the ultimate goal of treatment response modeling is to understand the relationship between treatment variables such as radiation dose and symptom groups resulting from FA. Hence, it is crucial to identify clinically more relevant symptom groups and improved response variables from those symptom groups for a quantitative analysis. The goal of this study is to design a computational method for finding clinically relevant symptom groups from PROs and to test associations between symptom groups and radiation dose. We propose a novel approach where exploratory factor analysis is followed by confirmatory factor analysis to determine the relevant number of symptom groups. We also propose to use a combination of symptoms in a symptom group identified as a new response variable in linear regression analysis to investigate the relationship between the symptom group and dose-volume variables. We analyzed patient-reported gastrointestinal symptom profiles from 3 datasets in prostate cancer patients treated with radiotherapy. The final structural model of each dataset was validated using the other two datasets and compared to four other existing FA methods. Our systematic EFA-CFA approach provided clinically more relevant solutions than other methods, resulting in new clinically relevant outcome variables that enabled a quantitative analysis. As a result, statistically significant correlations were found between some dose-volume variables to relevant anatomic structures and symptom groups identified by FA. Our proposed method can aid in the process of understanding PROs and provide a basis for improving our understanding of radiation-induced side effects.

  10. Liquidity indicator for the Croatian economy – Factor analysis approach

    Directory of Open Access Journals (Sweden)

    Mirjana Čižmešija

    2014-12-01

    Full Text Available Croatian business surveys (BS are conducted in the manufacturing industry, retail trade and construction sector. In all of these sectors, manager´s assessments of liquidity are measured. The aim of the paper was to form a new composite liquidity indicator by including business survey liquidity measures from all three covered economic sectors in the Croatian economy mentioned above. In calculating the leading indicator, a factor analysis approach was used. However, this kind of indicator does not exist in a Croatia or in any other European economy. Furthermore, the issue of Croatian companies´ illiquidity is highly neglected in the literature. The empirical analysis consists of two parts. In the first part the new liquidity indicator was formed using factor analysis. One factor (representing the new liquidity indicator; LI was extracted out of the three liquidity variables in three economic sectors. This factor represents the new liquidity indicator. In the second part, econometric models were applied in order to investigate the forecasting properties of the new business survey liquidity indicator, when predicting the direction of changes in Croatian industrial production. The quarterly data used in the research covered the period from January 2000 to April 2013. Based on econometric analysis, it can be concluded that the LI is a leading indicator of Croatia’s industrial production with better forecasting properties then the standard liquidity indicators (formed in a manufacturing industry.

  11. Traditional Risk Factors Versus Biomarkers for Prediction of Secondary Events in Patients With Stable Coronary Heart Disease: From the Heart and Soul Study.

    Science.gov (United States)

    Beatty, Alexis L; Ku, Ivy A; Bibbins-Domingo, Kirsten; Christenson, Robert H; DeFilippi, Christopher R; Ganz, Peter; Ix, Joachim H; Lloyd-Jones, Donald; Omland, Torbjørn; Sabatine, Marc S; Schiller, Nelson B; Shlipak, Michael G; Skali, Hicham; Takeuchi, Madoka; Vittinghoff, Eric; Whooley, Mary A

    2015-07-06

    Patients with stable coronary heart disease (CHD) have widely varying prognoses and treatment options. Validated models for risk stratification of patients with CHD are needed. We sought to evaluate traditional and novel risk factors as predictors of secondary cardiovascular (CV) events, and to develop a prediction model that could be used to risk stratify patients with stable CHD. We used independent derivation (912 participants in the Heart and Soul Study) and validation (2876 participants in the PEACE trial) cohorts of patients with stable CHD to develop a risk prediction model using Cox proportional hazards models. The outcome was CV events, defined as myocardial infarction, stroke, or CV death. The annual rate of CV events was 3.4% in the derivation cohort and 2.2% in the validation cohort. With the exception of smoking, traditional risk factors (including age, sex, body mass index, hypertension, dyslipidemia, and diabetes) did not emerge as the top predictors of secondary CV events. The top 4 predictors of secondary events were the following: N-terminal pro-type brain natriuretic peptide, high-sensitivity cardiac troponin T, urinary albumin:creatinine ratio, and current smoking. The 5-year C-index for this 4-predictor model was 0.73 in the derivation cohort and 0.65 in the validation cohort. As compared with variables in the Framingham secondary events model, the Heart and Soul risk model resulted in net reclassification improvement of 0.47 (95% CI 0.25 to 0.73) in the derivation cohort and 0.18 (95% CI 0.01 to 0.40) in the validation cohort. Novel risk factors are superior to traditional risk factors for predicting 5-year risk of secondary events in patients with stable CHD. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  12. Analytical and unitary approach in mesons electromagnetic form factor applications

    International Nuclear Information System (INIS)

    Liptaj, A.

    2010-07-01

    could be related to a very different type of experiment, a direct lifetime measurement, that was predominantly used to get the Γ π 0 →γγ value (unlike in the case of our evaluation or in the case of the PDG values for Γ η→γγ and Γ η ' →γγ . We are looking forward to analyze this issue and contribute to the solution. We finally study the behavior of the elastic pion EM form factor in the space-like domain. In this case we aimed to minimize the model dependence and based our approach only on the analytic properties of the form factor and the precise data in the time-like region. Our motivation was the data in the space-like region that, we believe, cannot be fully trusted. Further, we wanted to compare our prediction to other QCD inspired model. We have shown, that the prediction we obtain has only small model dependence. By making a prediction in the time-like region we have also shown that our approach is self-consistent, the prediction describes well the data points that were initially used to get it. Eventually we observed that our prediction is close tho the most recent result obtained in the framework of the AdS/CFT theory. The obtained results allow us to conclude that the unitary and analytic model and approach as such are correct tools to study meson form factors and we have shown, that they have big potential to give important results in several domains of particle physics. (author)

  13. Factors influencing crime rates: an econometric analysis approach

    Science.gov (United States)

    Bothos, John M. A.; Thomopoulos, Stelios C. A.

    2016-05-01

    The scope of the present study is to research the dynamics that determine the commission of crimes in the US society. Our study is part of a model we are developing to understand urban crime dynamics and to enhance citizens' "perception of security" in large urban environments. The main targets of our research are to highlight dependence of crime rates on certain social and economic factors and basic elements of state anticrime policies. In conducting our research, we use as guides previous relevant studies on crime dependence, that have been performed with similar quantitative analyses in mind, regarding the dependence of crime on certain social and economic factors using statistics and econometric modelling. Our first approach consists of conceptual state space dynamic cross-sectional econometric models that incorporate a feedback loop that describes crime as a feedback process. In order to define dynamically the model variables, we use statistical analysis on crime records and on records about social and economic conditions and policing characteristics (like police force and policing results - crime arrests), to determine their influence as independent variables on crime, as the dependent variable of our model. The econometric models we apply in this first approach are an exponential log linear model and a logit model. In a second approach, we try to study the evolvement of violent crime through time in the US, independently as an autonomous social phenomenon, using autoregressive and moving average time-series econometric models. Our findings show that there are certain social and economic characteristics that affect the formation of crime rates in the US, either positively or negatively. Furthermore, the results of our time-series econometric modelling show that violent crime, viewed solely and independently as a social phenomenon, correlates with previous years crime rates and depends on the social and economic environment's conditions during previous years.

  14. HYDROLYSIS OF STARCH BY THERMO-AND PH-STABLE GLUCOAMYLASE AT CHANGE PHYSICO-CHEMICAL FACTORS

    Directory of Open Access Journals (Sweden)

    V. S. Grigirov

    2013-01-01

    Full Text Available Regularity of the change rate of the enzymatic reactions depending on different temperatures, pH values in the formation and decay of the enzyme-substrate complex was investigated. Found that the kinetics of hydrolysis of starch by the action of heat and pH stable glucoamylases is complex as evidenced by the change in the value Km, which is a measure of the affinity of the enzyme to the substrate, active centers studied glucoamylases and starch undergo conformational changes at pH 4,0-5,0; 4,5-5,5 and a temperature of 60-65 °C.

  15. Identifying perinatal risk factors for infant maltreatment: an ecological approach

    Directory of Open Access Journals (Sweden)

    Hallisey Elaine J

    2006-12-01

    Full Text Available Abstract Background Child maltreatment and its consequences are a persistent problem throughout the world. Public health workers, human services officials, and others are interested in new and efficient ways to determine which geographic areas to target for intervention programs and resources. To improve assessment efforts, selected perinatal factors were examined, both individually and in various combinations, to determine if they are associated with increased risk of infant maltreatment. State of Georgia birth records and abuse and neglect data were analyzed using an area-based, ecological approach with the census tract as a surrogate for the community. Cartographic visualization suggested some correlation exists between risk factors and child maltreatment, so bivariate and multivariate regression were performed. The presence of spatial autocorrelation precluded the use of traditional ordinary least squares regression, therefore a spatial regression model coupled with maximum likelihood estimation was employed. Results Results indicate that all individual factors or their combinations are significantly associated with increased risk of infant maltreatment. The set of perinatal risk factors that best predicts infant maltreatment rates are: mother smoked during pregnancy, families with three or more siblings, maternal age less than 20 years, births to unmarried mothers, Medicaid beneficiaries, and inadequate prenatal care. Conclusion This model enables public health to take a proactive stance, to reasonably predict areas where poor outcomes are likely to occur, and to therefore more efficiently allocate resources. U.S. states that routinely collect the variables the National Center for Health Statistics (NCHS defines for birth certificates can easily identify areas that are at high risk for infant maltreatment. The authors recommend that agencies charged with reducing child maltreatment target communities that demonstrate the perinatal risks

  16. A Computational Drug Repositioning Approach for Targeting Oncogenic Transcription Factors

    Directory of Open Access Journals (Sweden)

    Kaitlyn M. Gayvert

    2016-06-01

    Full Text Available Mutations in transcription factor (TF genes are frequently observed in tumors, often leading to aberrant transcriptional activity. Unfortunately, TFs are often considered undruggable due to the absence of targetable enzymatic activity. To address this problem, we developed CRAFTT, a computational drug-repositioning approach for targeting TF activity. CRAFTT combines ChIP-seq with drug-induced expression profiling to identify small molecules that can specifically perturb TF activity. Application to ENCODE ChIP-seq datasets revealed known drug-TF interactions, and a global drug-protein network analysis supported these predictions. Application of CRAFTT to ERG, a pro-invasive, frequently overexpressed oncogenic TF, predicted that dexamethasone would inhibit ERG activity. Dexamethasone significantly decreased cell invasion and migration in an ERG-dependent manner. Furthermore, analysis of electronic medical record data indicates a protective role for dexamethasone against prostate cancer. Altogether, our method provides a broadly applicable strategy for identifying drugs that specifically modulate TF activity.

  17. Factors influencing groundwater quality: towards an integrated management approach.

    Science.gov (United States)

    De Giglio, O; Quaranta, A; Barbuti, G; Napoli, C; Caggiano, G; Montagna, M T

    2015-01-01

    The safety of groundwater resources is a serious issue, particularly when these resources are the main source of water for drinking, irrigation and industrial use in coastal areas. In Italy, 85% of the water used by the public is of underground origin. The aim of this report is to analyze the main factors that make groundwater vulnerable. Soil characteristics and filtration capacity can promote or hinder the diffusion of environmental contaminants. Global climate change influences the prevalence and degree of groundwater contamination. Anthropic pressure causes considerable exploitation of water resources, leading to reduced water availability and the progressive deterioration of water quality. Management of water quality will require a multidisciplinary, dynamic and practical approach focused on identifying the measures necessary to reduce contamination and mitigate the risks associated with the use of contaminated water resources.

  18. An Evaluation on Factors Influencing Decision making for Malaysia Disaster Management: The Confirmatory Factor Analysis Approach

    Science.gov (United States)

    Zubir, S. N. A.; Thiruchelvam, S.; Mustapha, K. N. M.; Che Muda, Z.; Ghazali, A.; Hakimie, H.

    2017-12-01

    For the past few years, natural disaster has been the subject of debate in disaster management especially in flood disaster. Each year, natural disaster results in significant loss of life, destruction of homes and public infrastructure, and economic hardship. Hence, an effective and efficient flood disaster management would assure non-futile efforts for life saving. The aim of this article is to examine the relationship between approach, decision maker, influence factor, result, and ethic to decision making for flood disaster management in Malaysia. The key elements of decision making in the disaster management were studied based on the literature. Questionnaire surveys were administered among lead agencies at East Coast of Malaysia in the state of Kelantan and Pahang. A total of 307 valid responses had been obtained for further analysis. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were carried out to analyse the measurement model involved in the study. The CFA for second-order reflective and first-order reflective measurement model indicates that approach, decision maker, influence factor, result, and ethic have a significant and direct effect on decision making during disaster. The results from this study showed that decision- making during disaster is an important element for disaster management to necessitate a successful collaborative decision making. The measurement model is accepted to proceed with further analysis known as Structural Equation Modeling (SEM) and can be assessed for the future research.

  19. GREEN APPROACH TO BULK AND TEMPLATE-FREE SYNTHESIS OF THERMALLY STABLE REDUCED POLYANILINE NANOFIBERS FOR CAPACITOR APPLICATIONS

    Science.gov (United States)

    An extremely simple green approach is described that generates bulk quantities of nanofibers of the electronic polymer polyaniline in fully reduced state (leucoemeraldine form) in one step without using any reducing agent, surfactants, and/or large amounts of insoluble templates....

  20. Assessing risk factors for dental caries: a statistical modeling approach.

    Science.gov (United States)

    Trottini, Mario; Bossù, Maurizio; Corridore, Denise; Ierardo, Gaetano; Luzzi, Valeria; Saccucci, Matteo; Polimeni, Antonella

    2015-01-01

    The problem of identifying potential determinants and predictors of dental caries is of key importance in caries research and it has received considerable attention in the scientific literature. From the methodological side, a broad range of statistical models is currently available to analyze dental caries indices (DMFT, dmfs, etc.). These models have been applied in several studies to investigate the impact of different risk factors on the cumulative severity of dental caries experience. However, in most of the cases (i) these studies focus on a very specific subset of risk factors; and (ii) in the statistical modeling only few candidate models are considered and model selection is at best only marginally addressed. As a result, our understanding of the robustness of the statistical inferences with respect to the choice of the model is very limited; the richness of the set of statistical models available for analysis in only marginally exploited; and inferences could be biased due the omission of potentially important confounding variables in the model's specification. In this paper we argue that these limitations can be overcome considering a general class of candidate models and carefully exploring the model space using standard model selection criteria and measures of global fit and predictive performance of the candidate models. Strengths and limitations of the proposed approach are illustrated with a real data set. In our illustration the model space contains more than 2.6 million models, which require inferences to be adjusted for 'optimism'.

  1. Dietary inulin intake and age can significantly affect intestinal absorption of calcium and magnesium in rats: a stable isotope approach

    Directory of Open Access Journals (Sweden)

    Mazur Andrzej

    2005-10-01

    Full Text Available Abstract Background previous studies have shown that non-digestible inulin-type fructan intake can increase intestinal mineral absorption in both humans and animals. However, this stimulatory effect on intestinal absorption may depend on experimental conditions such as duration of fermentable fiber intake, mineral diet levels and animals' physiological status, in particular their age. Objectives the aim of this study was to determine the effect of inulin intake on Ca and Mg absorption in rats at different age stages. Methods eighty male Wistar rats of four different ages (2, 5, 10 and 20 months were randomized into either a control group or a group receiving 3.75% inulin in their diet for 4 days and then 7.5% inulin for three weeks. The animals were fed fresh food and water ad libitum for the duration of the experiment. Intestinal absorption of Ca and Mg was determined by fecal monitoring using stable isotopic tracers. Ca and Mg status was also assessed. Results absorption of Ca and Mg was significantly lower in the aged rats (10 and 20 mo than in the young and adult rat groups. As expected, inulin intake increased Ca and Mg absorption in all four rat groups. However, inulin had a numerically greater effect on Ca absorption in aged rats than in younger rats whereas its effect on Mg absorption remained similar across all four rat age groups. Conclusion the extent of the stimulatory effect of inulin on absorption of Ca may differ according to animal ages. Further studies are required to explore this effect over longer inulin intake periods, and to confirm these results in humans.

  2. Dietary inulin intake and age can significantly affect intestinal absorption of calcium and magnesium in rats: a stable isotope approach

    Science.gov (United States)

    Coudray, Charles; Rambeau, Mathieu; Feillet-Coudray, Christine; Tressol, Jean Claude; Demigne, Christian; Gueux, Elyett; Mazur, Andrzej; Rayssiguier, Yves

    2005-01-01

    Background previous studies have shown that non-digestible inulin-type fructan intake can increase intestinal mineral absorption in both humans and animals. However, this stimulatory effect on intestinal absorption may depend on experimental conditions such as duration of fermentable fiber intake, mineral diet levels and animals' physiological status, in particular their age. Objectives the aim of this study was to determine the effect of inulin intake on Ca and Mg absorption in rats at different age stages. Methods eighty male Wistar rats of four different ages (2, 5, 10 and 20 months) were randomized into either a control group or a group receiving 3.75% inulin in their diet for 4 days and then 7.5% inulin for three weeks. The animals were fed fresh food and water ad libitum for the duration of the experiment. Intestinal absorption of Ca and Mg was determined by fecal monitoring using stable isotopic tracers. Ca and Mg status was also assessed. Results absorption of Ca and Mg was significantly lower in the aged rats (10 and 20 mo) than in the young and adult rat groups. As expected, inulin intake increased Ca and Mg absorption in all four rat groups. However, inulin had a numerically greater effect on Ca absorption in aged rats than in younger rats whereas its effect on Mg absorption remained similar across all four rat age groups. Conclusion the extent of the stimulatory effect of inulin on absorption of Ca may differ according to animal ages. Further studies are required to explore this effect over longer inulin intake periods, and to confirm these results in humans. PMID:16253138

  3. Amino acid stable isotope applications to deep-sea corals: A molecular geochemistry approach to reconstructing past ocean conditions

    Science.gov (United States)

    McMahon, K.; McCarthy, M. D.; Guilderson, T. P.; Sherwood, O.; Williams, B.; Larsen, T.; Glynn, D. S.

    2017-12-01

    Future climate change is predicted to alter ocean productivity, food web dynamics, biogeochemical cycling, and the efficacy of the biological pump. Proteinaceous deep-sea corals act as "living sediment traps," providing long-term, high-resolution records of exported surface ocean production and a window into past changes in ocean condition as a historical context for potential future changes. Here, we present recent work developing the application of compound-specific stable isotope analysis of individual amino acids to proteinaceous deep-sea corals to reconstruct past changes in phytoplankton community composition and biogeochemical cycling. We present new calibrations for molecular isotope comparisons between metabolically active coral polyp tissue and bioarchival proteinaceous skeleton. We then applied these techniques to deep-sea corals from the North Pacific Subtropical Gyre (NPSG) to reconstruct centennial to millennial time scale changes in phytoplankton community composition and biogeochemical cycling as a function of regional climate change. This work suggests that the NPSG has undergone multiple major phytoplankton regime shifts over the last millennium between prokaryotic and eukaryotic phytoplankton communities and associated sources of nitrogen fueling production. The most recent regime, which started around the end of the Little Ice Age and the onset of the Industrial era, is unprecedented in the last 1000 years and resulted in a 30-50% increase in diazotrophic cyanobacteria contribution to export production and an associated 17-27% increase in N2-fixation in the NPSG over last century. By offering the first direct phylogenetic context for long-term shifts in isotopic records of exported particulate organic matter, our data represent a major step forward in understanding the evolution of marine plankton community dynamics, food web architecture, biogeochemical cycling, and the climate feedback loops through the biological pump.

  4. Stable-isotope and solute-chemistry approaches to flow characterization in a forested tropical watershed, Luquillo Mountains, Puerto Rico

    Science.gov (United States)

    Martha A. Scholl; James B. Shanley; Sheila F. Murphy; Jane K. Willenbring; Grizelle Gonzalez

    2015-01-01

    The prospect of changing climate has led to uncertainty about the resilience of forested mountain watersheds in the tropics. In watersheds where frequent, high rainfall provides ample runoff, we often lack understanding of how the system will respond under conditions of decreased rainfall or drought. Factors that govern water supply, such as recharge rates and...

  5. Discrimination factors of carbon and nitrogen stable isotopes from diet to hair and scat in captive tigers (Panthera tigris) and snow leopards (Uncia uncia).

    Science.gov (United States)

    Montanari, Shaena; Amato, George

    2015-06-15

    In order to use stable isotope ratio values obtained from wild animal tissues, we must accurately calculate the differences in isotope ratios between diet and consumer (δtissue - δdiet). These values, called trophic discrimination factors (TDFs, denoted with ∆), are necessary for stable isotope ecology studies and are best calculated in controlled environments. Scat, hair, and diet samples were collected from captive tigers (n = 8) and snow leopards (n = 10) at the Bronx Zoo. The isotope ratios of carbon and nitrogen, the two most commonly used in ecological studies, of the samples were measured by continuous-flow isotope ratio mass spectrometry. The trophic discrimination factors were calculated for both carbon (δ(13)C values) and nitrogen (δ(15)N values). It was found that the only significant TDFs in this study were diet-hair, ∆(13)CHair, for snow leopards (5.97 ± 1.25‰) and tigers (6.45 ± 0.54‰), and diet-scat, ∆(15)NScat, in snow leopards (2.49 ± 1.30‰). The other mean isotope ratios were not significantly different from that of the premixed feline diet. The ∆(15)NHair values for both species were unusually low, potentially due to the protein content and quality of the feline diet. The discrimination factors of the stable isotopes of carbon and nitrogen calculated in this study can be applied to ecological studies of wild, non-captive terrestrial mammals. The effect of protein quality in isotope discrimination is also worthy of further investigation to better understand variation in TDFs. Carnivore scat is shown to be a valuable material for isotopic analysis. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Organization of accounting for factoring companies: risk-oriented approach

    Directory of Open Access Journals (Sweden)

    Vygivska I.M.

    2017-08-01

    Full Text Available To solve the problem of rational organization of accounting factoring activity the current research identifies the types of factoring operations typical for the accounting system of factoring company, and their place in this system. The recommended provisions, which must be fixed in the accounting policy of the enterprise-factor, are presented. Based on the identification of the most significant provisions of the factoring agreement, it is proposed to limit the amount of funding depending on the type of factoring. The risk factor matrix for factoring business is developed to improve the efficiency of their management and the accounting of operations due to risk management methods. The accounting of the factoring company is proposed taking into account the following components: 1 the moment of acceptance of the sold (deferred receivable to the accounting; 2 the features of factoring depending on its type; 3 the peculiarities of accounting registration of charges in factoring operations; 4 the procedure for inventorying factoring transactions.

  7. Factors That Influence Renewable Energy Technological Innovation in China: A Dynamic Panel Approach

    Directory of Open Access Journals (Sweden)

    Zheng-Xia He

    2018-01-01

    Full Text Available We examine the driving effects of various factors on technological innovation to renewables (TIRES, focusing on a set of 29 provinces in China, and apply a dynamic panel approach. China has become a leading player in research and development spending in renewables, and the dynamic panel estimators we use prove themselves to be suitable in handling the persistent effect on TIRES. The level of TIRES in the previous periods is positively and highly correlated with that in the current period and confirmed the need for a stable and consistent policy support for renewables. Electricity consumption is the most important driver for all renewables and wind energy, but the driving effect was weaker for solar energy and biomass. Research and development intensity is the most important driver for biomass, but is only the second most important driver for all renewables, solar energy and wind energy. Unexpectedly, electricity price has had significant negative impacts on TIRES, which reveals that lowering electricity prices will lead to higher innovation in renewables. The driving effect of renewable energy tariff surcharge subsidy is not significant, which means that Chinese subsidy policy has not played the desired role. The driving effect of installed renewable energy capacity is also minimal, which may be due to the fact that overcapacity will hinder TIRES in China. This paper may help policy-makers and the industry understand how to promote TIRES in China effectively based on these above influential factors.

  8. A statistical approach to estimating soil-to-plant transfer factor of strontium in agricultural fields

    International Nuclear Information System (INIS)

    Ishikawa, Nao; Tagami, Keiko; Uchida, Shigeo

    2009-01-01

    Soil-to-plant transfer factor (TF) is one of the important parameters in radiation dose assessment models for the environmental transfer of radionuclides. Since TFs are affected by several factors, including radionuclides, plant species and soil properties, development of a method for estimation of TF using some soil and plant properties would be useful. In this study, we took a statistical approach to estimating the TF of stable strontium (TF Sr ) from selected soil properties and element concentrations in plants, which was used as an analogue of 90 Sr. We collected the plant and soil samples used for the study from 142 agricultural fields throughout Japan. We applied a multiple linear regression analysis in order to get an empirical equation to estimate TF Sr . TF Sr could be estimated from the Sr concentration in soil (C Sr soil ) and Ca concentration in crop (C Ca crop ) using the following equation: log TF Sr =-0.88·log C Sr soil +0.93·log C Ca crop -2.53. Then, we replaced our data with Ca concentrations in crops from a food composition database compiled by the Japanese government. Finally, we predicted TF Sr using Sr concentration in soil from our data and Ca concentration in crops from the database of food composition. (author)

  9. Teasing Foggy Memories out of Pines on the California Channel Islands Using Tree-Ring Width and Stable Isotope Approaches

    Science.gov (United States)

    Williams, A. P.; Still, C. J.; Fischer, D. T.; Leavitt, S. W.

    2006-12-01

    The coast of California is home to many rare, endemic conifers and other plants that are not well adapted to the Mediterranean climate that prevails across most of the state. It has long been suggested that coastal pines survived the early-Pleistocene transition to a warmer and drier environment because they benefit from frequent fog and low stratus clouds that provide much needed water inputs and shading during the rainless summer. Here, we report evidence for the importance of this summer cloudiness to Torrey pines (Pinus torreyana) growing on Santa Rosa Island in Channel Islands National Park. We developed a tree-ring width chronology and quantified the relative importance of winter/spring precipitation and summer fog by comparing ring widths to nearby rainfall records and airport cloud-ceiling height data. While winter/spring precipitation explains most of the variation in annual tree-ring width (R2 = 0.592), the frequency of summertime fog correlated significantly and positively with annual ring width for 52 years of available fog data when the effect of winter/spring precipitation was removed (R2 = 0.118). The correlation between fog frequency and ring width decreased sharply when the range of possible cloud-ceiling heights deviated from the habitat range of the Torrey pine stand, emphasizing the importance of direct cloud immersion to these pines. In addition, the relationship between fog frequency and ring width was strongest in the 26 years that had enough winter/spring rainfall to maintain above-average soil moisture throughout the dry summer months (R2 = 0.312). This suggests that Torrey pines have an adaptive growing season length and that summer fog-water inputs are supplemental but not substantial enough to sustain tree growth independently. It may also be suggested that when summer growth does occur, the frequency of summer fog and stratus may govern growing season length. This made a "fog signal" difficult to detect in the stable isotope (carbon and

  10. Diet-tissue discrimination factors and turnover of carbon and nitrogen stable isotopes in tissues of an adult predatory coral reef fish, Plectropomus leopardus.

    Science.gov (United States)

    Matley, J K; Fisk, A T; Tobin, A J; Heupel, M R; Simpfendorfer, C A

    2016-01-15

    Stable isotope ratios (δ(13)C and δ(15)N values) provide a unique perspective into the ecology of animals because the isotope ratio values of consumers reflect the values in food. Despite the value of stable isotopes in ecological studies, the lack of species-specific experimentally derived diet-tissue discrimination factors (DTDFs) and turnover rates limits their application at a broad scale. Furthermore, most aquatic feeding experiments use temperate, fast-growing fish species and few have considered medium- to large-sized adults with low growth rates from tropical ecosystems. A controlled-diet stable isotope feeding trial was conducted over a 196-day period for the adult predatory reef fish leopard coralgrouper (Plectropomus leopardus). This study calculated δ(13)C and δ(15)N DTDFs and turnover rates in five tissues (liver, plasma, red blood cells (RBC), fin, and muscle) using a continuous flow isotope ratio mass spectrometer equipped with an elemental analyzer. In addition, the effect of chemical lipid extraction (LE) on stable isotope values was examined for each tissue. Turnover was mainly influenced by metabolism (as opposed to growth) with LE δ(15)N half-life values lowest in fin (37 days) and plasma (66 days), and highest in RBC (88 days) and muscle (126 days). The diet-tissue discrimination factors for δ(15)N values in all tissues (Δ(15)N: -0.15 to 1.84‰) were typically lower than commonly reported literature values. Lipid extraction altered both δ(15) N and δ(13)C values compared with untreated samples; however, for the δ(15)N values, the differences were small (mean δ(15)N(LE-Bulk) stable isotope data for medium- to large-sized fish and demonstrates that DTDFs developed for temperate fish species, particularly for δ(15)N values, may not apply to tropical species. Sampling of muscle and/or RBC is recommended for a relatively long-term representation of feeding habits, while plasma and/or fin should be used for a more recent indication of

  11. A novel approach to monitor glucose metabolism using stable isotopically labelled glucose in longitudinal studies in mice.

    Science.gov (United States)

    van Dijk, T H; Laskewitz, A J; Grefhorst, A; Boer, T S; Bloks, V W; Kuipers, F; Groen, A K; Reijngoud, D J

    2013-04-01

    The aetiology of insulin resistance is still an enigma. Mouse models are frequently employed to study the underlying pathology. The most commonly used methods to monitor insulin resistance are the HOMA-IR, glucose or insulin tolerance tests and the hyperinsulinemic euglycaemic clamp (HIEC). Unfortunately, these tests disturb steady state glucose metabolism. Here we describe a method in which blood glucose kinetics can be determined in fasted mice without noticeably perturbing glucose homeostasis. The method involves an intraperitoneal injection of a trace amount of [6,6-(2)H2]glucose and can be performed repeatedly in individual mice. The validity and performance of this novel method was tested in mice fed on chow or high-fat diet for a period of five weeks. After administering the mice with [6,6-(2)H2]glucose, decay of the glucose label was followed in small volumes of blood collected by tail tip bleeding during a 90-minute period. The total amount of blood collected was less than 120 μL. This novel approach confirmed in detail the well-known increase in insulin resistance induced by a high-fat diet. The mice showed reduced glucose clearance rate, and reduced hepatic and peripheral insulin sensitivity. To compensate for this insulin resistance, β-cell function was slightly increased. We conclude that this refinement of existing methods enables detailed information of glucose homeostasis in mice. Insulin resistance can be accurately determined while mechanistic insight is obtained in underlying pathology. In addition, this novel approach reduces the number of mice needed for longitudinal studies of insulin sensitivity and glucose metabolism.

  12. UV-laser microdissection system - A novel approach for the preparation of high-resolution stable isotope records (δ13C/δ18O) from tree rings

    Science.gov (United States)

    Schollaen, Karina; Helle, Gerhard

    2013-04-01

    Intra-annual stable isotope (δ13C and δ18O) studies of tree rings at various incremental resolutions have been attempting to extract valuable seasonal climatic and environmental information or assessing plant ecophysiological processes. For preparing high-resolution isotope samples normally wood segments or cores are mechanically divided in radial direction or cut in tangential direction. After mechanical dissection, wood samples are ground to a fine powder and either cellulose is extracted or bulk wood samples are analyzed. Here, we present a novel approach for the preparation of high-resolution stable isotope records from tree rings using an UV-laser microdissection system. Firstly, tree-ring cellulose is directly extracted from wholewood cross-sections largely leaving the wood anatomical structure intact and saving time as compared to the classical procedure. Secondly, micro-samples from cellulose cross-sections are dissected with an UV-Laser dissection microscope. Tissues of interest from cellulose cross-sections are identified and marked precisely with a screen-pen and dissected via an UV-laser beam. Dissected cellulose segments were automatically collected in capsules and are prepared for stable isotope (δ13C and δ18O) analysis. The new techniques facilitate inter- and intra-annual isotope analysis on tree-ring and open various possibilities for comparisons with wood anatomy in plant eco-physiological studies. We describe the design and the handling of this novel methodology and discuss advantages and constraints given by the example of intra-annual oxygen isotope analysis on tropical trees.

  13. A randomized study of coconut oil versus sunflower oil on cardiovascular risk factors in patients with stable coronary heart disease

    Directory of Open Access Journals (Sweden)

    Maniyal Vijayakumar

    2016-07-01

    Conclusion: Coconut oil even though rich in saturated fatty acids in comparison to sunflower oil when used as cooking oil media over a period of 2 years did not change the lipid-related cardiovascular risk factors and events in those receiving standard medical care.

  14. Longitudinal Tests of Competing Factor Structures for the Rosenberg Self-Esteem Scale: Traits, Ephemeral Artifacts, and Stable Response Styles

    Science.gov (United States)

    Marsh, Herbert W.; Scalas, L. Francesca; Nagengast, Benjamin

    2010-01-01

    Self-esteem, typically measured by the Rosenberg Self-Esteem Scale (RSE), is one of the most widely studied constructs in psychology. Nevertheless, there is broad agreement that a simple unidimensional factor model, consistent with the original design and typical application in applied research, does not provide an adequate explanation of RSE…

  15. A Confirmatory Factor Analysis Approach to Construct Validation.

    Science.gov (United States)

    Rezmovic, Eva Lantos; Rezmovic, Victor

    1981-01-01

    A multitrait-multimethod matrix containing two methods of measuring 12 personality traits was analyzed and confirmatory factor analysis was applied to the data. Although unexplained variance remained, method factors and a general personality factor significantly improved the fit of a model containing only trait factors. (Author/RL)

  16. Population-genetic approach to standardization of radiation and non-radiation factors

    International Nuclear Information System (INIS)

    Telnov, I.

    2006-01-01

    population level. Of 65 analyses of association between diseases and unfavorable effects and various genetic polymorphic systems, 27 had negative results. Other 38 had significant, i.e. positive results. Respective G.S.R.R. varied accordingly in the range from 1.2 to 2.5. Averaged G.S.R.R. for some genetic systems ranged from 1.4 to 1.9. More stable and closer values of averaged G.S.R.R. calculated for various categories of effects: pathologies due to radiation and non-radiation factors - 1.51; non-tumor (1,47) and tumor (1,54) diseases; average life expectancy - 1.34. Population-averaged or integral value of G.S.R.R. was about 1.5. This value can be used as genetic predisposition coefficient (C.G.P.) for correction in averaging of environmental population level factors. Such correction can be done by decreasing of permissible standard value by the value of C.G.P. to calculate population-genetic standard. It should be noted that population-genetic standards decrease risk of development of unfavorable consequences due to effect of environmental factors in individuals with genetic predisposition to the general population level. An important advantage of this approach is that there is no need to account for all existing variations of genetic predisposition to multiform unfavorable environmental factors

  17. Population-genetic approach to standardization of radiation and non-radiation factors

    Energy Technology Data Exchange (ETDEWEB)

    Telnov, I. [Southern Urals Biophysics Institute, Ozersk (Russian Federation)

    2006-07-01

    characteristics on population level. Of 65 analyses of association between diseases and unfavorable effects and various genetic polymorphic systems, 27 had negative results. Other 38 had significant, i.e. positive results. Respective G.S.R.R. varied accordingly in the range from 1.2 to 2.5. Averaged G.S.R.R. for some genetic systems ranged from 1.4 to 1.9. More stable and closer values of averaged G.S.R.R. calculated for various categories of effects: pathologies due to radiation and non-radiation factors - 1.51; non-tumor (1,47) and tumor (1,54) diseases; average life expectancy - 1.34. Population-averaged or integral value of G.S.R.R. was about 1.5. This value can be used as genetic predisposition coefficient (C.G.P.) for correction in averaging of environmental population level factors. Such correction can be done by decreasing of permissible standard value by the value of C.G.P. to calculate population-genetic standard. It should be noted that population-genetic standards decrease risk of development of unfavorable consequences due to effect of environmental factors in individuals with genetic predisposition to the general population level. An important advantage of this approach is that there is no need to account for all existing variations of genetic predisposition to multiform unfavorable environmental factors.

  18. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1994-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets, with a few more additions - with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers - exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the foree of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc. (orig.)

  19. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  20. Evapotranspiration partitioning in the highest alpine meadow zones through in-situ chamber and dual stable water isotope approaches

    Science.gov (United States)

    Cui, J.; Tian, L.

    2017-12-01

    Understanding plant functionality within the water cycles of grassland ecosystems is crucial for obtaining both regional water balance and plant adaptability in the context of ongoing climate change. The transpiration to evapotranspiration ratio (T/ET) is an indicator of plant's contribution to ecosystem water cycle. In this study, we used high-frequency laser spectroscopy (L2130-i), three custom-built chambers, and eddy covariance techniques, to constrain the role played by plants in evapotranspiration over an alpine meadow ecosystem in the central Tibetan Plateau (TP). Three different sizes of chambers are used to direct measure the isotopic compositions in evapotranspiration (δET), evaporation (δE) and transpiration (δT). The consistent T/ET between δ18O and δD manifests that chamber and dual isotope tracers are robust methods to estimate T/ET in alpine meadow zone. Sensitivity analysis shows that the isotopic composition of evapotranspiration is the main contributor to, and the uncertainty source for, the T/ET estimate. The influence of meteorological and biotic factors on T/ET is also discussed. The results from this study indicate that plants play an important role in the water cycles of alpine meadow ecosystems despite the sparse distribution of plant cover. We also synthesized the published T/ET data over the entire TP region, and found a good relation between T/ET and leaf area index (LAI). Moreover, soil water content played some role in controlling T/ET beyond the LAI in arid/semiarid regions such as the TP. More than half of the TP is covered by grassland, but its low biomass and shallow rooting depth make it very vulnerable to climate change variables such as air temperature warming and variations in precipitation. Given the crucial role played by plants in an ecosystem's water cycle, any variations in grassland cover are likely to exert a critical impact on the regional hydrological cycle, and even the regional climate.

  1. SU(2 and SU(1,1 Approaches to Phase Operators and Temporally Stable Phase States: Applications to Mutually Unbiased Bases and Discrete Fourier Transforms

    Directory of Open Access Journals (Sweden)

    Maurice R. Kibler

    2010-07-01

    Full Text Available We propose a group-theoretical approach to the generalized oscillator algebra Aκ recently investigated in J. Phys. A: Math. Theor. 2010, 43, 115303. The case κ ≥ 0 corresponds to the noncompact group SU(1,1 (as for the harmonic oscillator and the Pöschl-Teller systems while the case κ < 0 is described by the compact group SU(2 (as for the Morse system. We construct the phase operators and the corresponding temporally stable phase eigenstates for Aκ in this group-theoretical context. The SU(2 case is exploited for deriving families of mutually unbiased bases used in quantum information. Along this vein, we examine some characteristics of a quadratic discrete Fourier transform in connection with generalized quadratic Gauss sums and generalized Hadamard matrices.

  2. ERP system implementation costs and selection factors of an implementation approach

    DEFF Research Database (Denmark)

    Johansson, Björn; Sudzina, Frantisek; Newman, Mike

    2011-01-01

    Different approaches on implementation of enterprise resource planning (ERPs) systems exist. In this article, we investigate relationship between factors influencing selection of implementation approach and companies' ability to stay within budget when implementing ERPs. The question is: do factors...... of an implementation approach; 2) companies with information strategies are more likely to stay within budget regarding ERP systems implementation. However, we also found that: 3) implementation approach does not significantly influence ability to stay within budget; 4) a clear relationship between factors influencing...

  3. Validation of a single biopsy approach and bolus protein feeding to determine myofibrillar protein synthesis in stable isotope tracer studies in humans

    Directory of Open Access Journals (Sweden)

    Baker Steven K

    2011-03-01

    Full Text Available Abstract Background Minimizing the number of muscle biopsies has important methodological implications and minimizes subject discomfort during a stable isotope amino acid infusion. We aimed to determine the reliability of obtaining a single muscle biopsy for the calculation of muscle protein fractional synthetic rate (FSR as well as the amount of incorporation time necessary to obtain that biopsy after initiating a stable isotope infusion (Study 1. The calculation of muscle protein FSR requires tracer steady-state during the stable isotope infusion. Therefore, a second aim was to examine if steady-state conditions are compromised in the precursor pools (plasma free or muscle intracellular [IC] after ingestion of a tracer enriched protein drink and after resistance exercise (Study 2. Methods Sixteen men (23 ± 3 years; BMI = 23.8 ± 2.2 kg/m2, means ± SD were randomized to perform Study 1 or Study 2 (n = 8, per study. Subjects received a primed, constant infusion of L-[ring-13C6]phenylalanine coupled with muscle biopsies of the vastus lateralis to measure rates of myofibrillar protein synthesis (MPS. Subjects in Study 2 were fed 25 g of whey protein immediately after an acute bout of unilateral resistance exercise. Results There was no difference (P = 0.3 in rates of MPS determined using the steady-state precursor-product equation and determination of tracer incorporation between sequential biopsies 150 min apart or using plasma protein as the baseline enrichment, provided the infusion length was sufficient (230 ± 0.3 min. We also found that adding a modest amount of tracer (4% enriched, calculated based on the measured phenylalanine content of the protein (3.5% in the drink, did not compromise steady-state conditions (slope of the enrichment curve not different from zero in the plasma free or, more importantly, the IC pool (both P > 0.05. Conclusions These data demonstrate that the single biopsy approach yields comparable rates of muscle

  4. Validation of a single biopsy approach and bolus protein feeding to determine myofibrillar protein synthesis in stable isotope tracer studies in humans.

    Science.gov (United States)

    Burd, Nicholas A; West, Daniel Wd; Rerecich, Tracy; Prior, Todd; Baker, Steven K; Phillips, Stuart M

    2011-03-09

    Minimizing the number of muscle biopsies has important methodological implications and minimizes subject discomfort during a stable isotope amino acid infusion. We aimed to determine the reliability of obtaining a single muscle biopsy for the calculation of muscle protein fractional synthetic rate (FSR) as well as the amount of incorporation time necessary to obtain that biopsy after initiating a stable isotope infusion (Study 1). The calculation of muscle protein FSR requires tracer steady-state during the stable isotope infusion. Therefore, a second aim was to examine if steady-state conditions are compromised in the precursor pools (plasma free or muscle intracellular [IC]) after ingestion of a tracer enriched protein drink and after resistance exercise (Study 2). Sixteen men (23 ± 3 years; BMI = 23.8 ± 2.2 kg/m2, means ± SD) were randomized to perform Study 1 or Study 2 (n = 8, per study). Subjects received a primed, constant infusion of L-[ring-13C6]phenylalanine coupled with muscle biopsies of the vastus lateralis to measure rates of myofibrillar protein synthesis (MPS). Subjects in Study 2 were fed 25 g of whey protein immediately after an acute bout of unilateral resistance exercise. There was no difference (P = 0.3) in rates of MPS determined using the steady-state precursor-product equation and determination of tracer incorporation between sequential biopsies 150 min apart or using plasma protein as the baseline enrichment, provided the infusion length was sufficient (230 ± 0.3 min). We also found that adding a modest amount of tracer (4% enriched), calculated based on the measured phenylalanine content of the protein (3.5%) in the drink, did not compromise steady-state conditions (slope of the enrichment curve not different from zero) in the plasma free or, more importantly, the IC pool (both P > 0.05). These data demonstrate that the single biopsy approach yields comparable rates of muscle protein synthesis, provided a longer incorporation time is

  5. Combined effect of boundary layer recirculation factor and stable energy on local air quality in pearl river delta over southern China.

    Science.gov (United States)

    Li, Haowen; Wang, Baomin; Fang, Xingqin; Zhu, Wei; Fan, Qi; Liao, Zhiheng; Liu, Jian; Zhang, Asi; Fan, Shaojia

    2018-03-01

    Atmospheric boundary layer (ABL) has a significant impact on the spatial and temporal distribution of air pollutants. In order to gain a better understanding of how ABL affects the variation of air pollutants, atmospheric boundary layer observations were performed at Sanshui in the Pearl River Delta (PRD) region over Southern China during the winter of 2013. Two types of typical ABL status which could lead to air pollution were analyzed comparatively: weak vertical diffusion ability type (WVDAT) and weak horizontal transportation ability type (WHTAT). Results show: 1) WVDAT was featured with moderate wind speed, consistent wind direction, and thick inversion layer at 600 ~ 1000m above ground level (AGL), and air pollutants were restricted in the low altitude due to the stable atmospheric structure; 2) WHTAT was characterized with calm wind, varied wind direction and shallow intense ground inversion layer, and air pollutants accumulated in the local because of strong recirculation in the low ABL; 3) Recirculation Factor (RF) and Stable Energy (SE) were proved to be good indicators for horizontal transportation ability and vertical diffusion ability of the atmosphere, respectively. Combined utilization of RF and SE can be very helpful in the evaluation of air pollution potential of the ABL. Implications Air quality data from ground and meteorological data collected from radio sounding in Sanshui in Pearl River Delta show that local air quality was poor when wind reversal was pronounced or temperature stratification state is stable. It should take the combination of horizontal and vertical transportation ability of local atmosphere into consideration when evaluating local environmental bearing capacity for air pollution.

  6. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  7. Lessons learned from different approaches towards classifying personal factors.

    Science.gov (United States)

    Müller, Rachel; Geyh, Szilvia

    2015-01-01

    To examine and compare existing suggestions towards a classification of Personal Factors (PF) of the International Classification of Functioning, Disability and Health (ICF). Qualitative and quantitative content analyses of available categorizations of PF are conducted. While the eight categorizations greatly differ in their background and structure, the broad content areas covered seem to be similar and reflect the ICF definition of PF. They cover to various degrees 12 broad content areas: socio-demographic factors, behavioral and lifestyle factors, cognitive psychological factors, social relationships, experiences and biography, coping, emotional factors, satisfaction, other health conditions, biological/physiological factors, personality, motives/motivation. In comparing these categorizations, a common core of content issues for a potential ICF PF classification could be identified and valuable lessons learned. This can contribute to future classification development activities in relation to PF.

  8. Evolution of potent and stable placental-growth-factor-1-targeting CovX-bodies from phage display peptide discovery.

    Science.gov (United States)

    Bower, Kristen E; Lam, Son N; Oates, Bryan D; Del Rosario, Joselyn R; Corner, Emily; Osothprarop, Trina F; Kinhikar, Arvind G; Hoye, Julie A; Preston, R Ryan; Murphy, Robert E; Campbell, Lioudmila A; Huang, Hanhua; Jimenez, Judith; Cao, Xia; Chen, Gang; Ainekulu, Zemeda W; Datt, Aakash B; Levin, Nancy J; Doppalapudi, Venkata R; Pirie-Shepherd, Steven R; Bradshaw, Curt; Woodnutt, Gary; Lappe, Rodney W

    2011-03-10

    Novel phage-derived peptides are the first reported molecules specifically targeting human placental growth factor 1 (PlGF-1). Phage data enabled peptide modifications that decreased IC(50) values in PlGF-1/VEGFR-1 competition ELISA from 100 to 1 μM. Peptides exhibiting enhanced potency were bioconjugated to the CovX antibody scaffold 1 (CVX-2000), generating bivalent CovX-Bodies with 2 nM K(D) against PlGF-1. In vitro and in vivo peptide cleavage mapping studies enabled the identification of proteolytic hotspots that were subsequently chemically modified. These changes decreased IC(50) to 0.4 nM and increased compound stability from 5% remaining at 6 h after injection to 35% remaining at 24 h with a β phase half-life of 75 h in mice. In cynomolgus monkey, a 78 h β half-life was observed for lead compound 2. The pharmacological properties of 2 are currently being explored.

  9. The stable repression of mesenchymal program is required for hepatocyte identity: a novel role for hepatocyte nuclear factor 4α.

    Science.gov (United States)

    Santangelo, Laura; Marchetti, Alessandra; Cicchini, Carla; Conigliaro, Alice; Conti, Beatrice; Mancone, Carmine; Bonzo, Jessica A; Gonzalez, Frank J; Alonzi, Tonino; Amicone, Laura; Tripodi, Marco

    2011-06-01

    The concept that cellular terminal differentiation is stably maintained once development is complete has been questioned by numerous observations showing that differentiated epithelium may undergo an epithelial-to-mesenchymal transition (EMT) program. EMT and the reverse process, mesenchymal-to-epithelial transition (MET), are typical events of development, tissue repair, and tumor progression. In this study, we aimed to clarify the molecular mechanisms underlying these phenotypic conversions in hepatocytes. Hepatocyte nuclear factor 4α (HNF4α) was overexpressed in different hepatocyte cell lines and the resulting gene expression profile was determined by real-time quantitative polymerase chain reaction. HNF4α recruitment on promoters of both mesenchymal and EMT regulator genes was determined by way of electrophoretic mobility shift assay and chromatin immunoprecipitation. The effect of HNF4α depletion was assessed in silenced cells and in the context of the whole liver of HNF4 knockout animals. Our results identified key EMT regulators and mesenchymal genes as new targets of HNF4α. HNF4α, in cooperation with its target HNF1α, directly inhibits transcription of the EMT master regulatory genes Snail, Slug, and HMGA2 and of several mesenchymal markers. HNF4α-mediated repression of EMT genes induces MET in hepatomas, and its silencing triggers the mesenchymal program in differentiated hepatocytes both in cell culture and in the whole liver. The pivotal role of HNF4α in the induction and maintenance of hepatocyte differentiation should also be ascribed to its capacity to continuously repress the mesenchymal program; thus, both HNF4α activator and repressor functions are necessary for the identity of hepatocytes. Copyright © 2011 American Association for the Study of Liver Diseases.

  10. Hydrogeochemistry and quality of surface water and groundwater in the vicinity of Lake Monoun, West Cameroon: approach from multivariate statistical analysis and stable isotopic characterization.

    Science.gov (United States)

    Kamtchueng, Brice T; Fantong, Wilson Y; Wirmvem, Mengnjo J; Tiodjio, Rosine E; Takounjou, Alain F; Ndam Ngoupayou, Jules R; Kusakabe, Minoru; Zhang, Jing; Ohba, Takeshi; Tanyileke, Gregory; Hell, Joseph V; Ueda, Akira

    2016-09-01

    With the use of conventional hydrogeochemical techniques, multivariate statistical analysis, and stable isotope approaches, this paper investigates for the first time surface water and groundwater from the surrounding areas of Lake Monoun (LM), West Cameroon. The results reveal that waters are generally slightly acidic to neutral. The relative abundance of major dissolved species are Ca(2+) > Mg(2+) > Na(+) > K(+) for cations and HCO3 (-) ≫ NO3 (-) > Cl(-) > SO4 (2-) for anions. The main water type is Ca-Mg-HCO3. Observed salinity is related to water-rock interaction, ion exchange process, and anthropogenic activities. Nitrate and chloride have been identified as the most common pollutants. These pollutants are attributed to the chlorination of wells and leaching from pit latrines and refuse dumps. The stable isotopic compositions in the investigated water sources suggest evidence of evaporation before recharge. Four major groups of waters were identified by salinity and NO3 concentrations using the Q-mode hierarchical cluster analysis (HCA). Consistent with the isotopic results, group 1 represents fresh unpolluted water occurring near the recharge zone in the general flow regime; groups 2 and 3 are mixed water whose composition is controlled by both weathering of rock-forming minerals and anthropogenic activities; group 4 represents water under high vulnerability of anthropogenic pollution. Moreover, the isotopic results and the HCA showed that the CO2-rich bottom water of LM belongs to an isolated hydrological system within the Foumbot plain. Except for some springs, groundwater water in the area is inappropriate for drinking and domestic purposes but good to excellent for irrigation.

  11. Using Stable Isotopes to Link Nutrient Sources in the Everglades and Biological Sinks in Florida Bay: A Biogeochemical Approach to Evaluate Ecosystem Response to Changing Nutrient Regimes

    Science.gov (United States)

    Hoare, A. M.; Hollander, D. J.; Heil, C.; Glibert, P.; Murasko, S.; Revilla, M.; Alexander, J.

    2005-05-01

    Anthropogenic influences in South Florida have led to deterioration of its two major ecosystems, the Everglades wetlands and the Florida Bay estuary. Consequently, the Comprehensive Everglades Restoration Plan has been proposed to restore the Everglades ecosystem; however, restoration efforts will likely exert new ecological changes in the Everglades and ultimately Florida Bay. The success of the Florida Everglades restoration depends on our understanding and ability to predict how regional changes in the distribution and composition of dissolved organic and inorganic nutrients will direct the downstream biogeochemical dynamics of Florida Bay. While the transport of freshwater and nutrients to Florida Bay have been studied, much work remains to directly link nutrient dynamics in Florida Bay to nutrient sources in the Everglades. Our study uses stable C and N isotopic measurements of chemical and biological materials from the Everglades and Florida Bay as part of a multi-proxy approach to link nutrient sources in the Everglades to biological sinks in Florida Bay. Isotopic analyses of dissolved and particulate species of water, aquatic vegetation and sedimentary organic matter show that the watersheds within the Everglades are chemically distinct and that these signatures are also reflected in the bay. A large east-west gradient in both carbon and nitrogen (as much as 10‰ for δ15N POM) reflect differing nutrient sources for each region of Florida Bay and is strongly correlated with upstream sources in the Everglades. Isotopic signatures also reflect seasonal relationships associated with wet and dry periods. High C and N measurements of DOM and POM measurements suggest significant influence from waste water in Canal C-111 in eastern Florida Bay, particularly during the dry season. These observations show that nutrients from the Everglades watersheds enter Florida Bay and are important in controlling biogeochemical processes in the bay. This study proves that

  12. Impact of non-steroidal anti-inflammatory drugs (NSAIDs) on cardiovascular outcomes in patients with stable atherothrombosis or multiple risk factors.

    Science.gov (United States)

    Barthélémy, Olivier; Limbourg, Tobias; Collet, Jean Philippe; Beygui, Farzin; Silvain, Johanne; Bellemain-Appaix, Anne; Cayla, Guillaume; Chastre, Thomas; Baumgartner, Iris; Röther, Joachim; Zeymer, Uwe; Bhatt, Deepak L; Steg, Gabriel; Montalescot, Gilles

    2013-03-10

    We aimed to assess whether the use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with an increased risk of cardiovascular (CV) events in stable patients with established atherothrombosis or multiple risk factors. We analysed the 23,728 European patients of the REACH Registry; 20,588 (86.8%) had established atherothrombotic disease and 3140 (13.2%) had multiple risk factors only. Aspirin (ASA) and/or NSAIDs use was determined at enrolment and ischemic events were recorded over two years of follow-up. cMACCE was defined as the composite of CV death, MI or stroke. Bleeding was defined as any bleeding leading to both hospitalisation and transfusion. The mean age of population was 67.2±9.8years. At baseline, 1573 patients (6.6%) received NSAIDs and 15,395 (64.9%) received ASA. Four groups were defined: 1) no ASA/no NSAIDs, 2) ASA only, 3) NSAIDs only, 4) NSAIDs+ASA, with 7722 (32.5%), 14,433 (60.8%), 611 (2.6%) and 962 (4.1%) patients in these groups, respectively. Among the 22,028 (92.8%) with complete 2-year follow-up, 683 (3.2%) died from CV causes, while 395 (1.9%) had MI, 665 (3.1%) stroke, 1651 (7.6%) cMACCE and 199 (1.0%) bleeding. After adjustment, NSAID use was independently associated with an increased risk of stroke (OR 1.635; 95% CI 1.239-2.159, pNSAID use and MI or MACCE. In stable atherothrombosis patients, the use of NSAIDs appears to be independently associated with an increased cerebrovascular event risk. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Electromagnetic form factors of baryons in an algebraic approach

    International Nuclear Information System (INIS)

    Bijker, R.; Leviatan, A.

    1999-01-01

    We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered. (Author)

  14. Electromagnetic form factors of baryons in an algebraic approach

    Energy Technology Data Exchange (ETDEWEB)

    Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)

    1999-07-01

    We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered. (Author)

  15. Predictive and Prognostic Factors in Colorectal Cancer: A Personalized Approach

    Directory of Open Access Journals (Sweden)

    Timothy A. Rockall

    2011-03-01

    Full Text Available It is an exciting time for all those engaged in the treatment of colorectal cancer. The advent of new therapies presents the opportunity for a personalized approach to the patient. This approach considers the complex genetic mechanisms involved in tumorigenesis in addition to classical clinicopathological staging. The potential predictive and prognostic biomarkers which have stemmed from the study of the genetic basis of colorectal cancer and therapeutics are discussed with a focus on mismatch repair status, KRAS, BRAF, 18qLOH, CIMP and TGF-β.

  16. An ISM approach for analyzing the factors in technology transfer

    Directory of Open Access Journals (Sweden)

    Mohammad Mahdavi Mazdeh

    2015-07-01

    Full Text Available Technology transfer, from research and technology organizations (RTOs toward local industries, is considered as one of important and significant strategies for countries' industrial development. In addition to recover the enormous costs of research and development for RTOs, successful technology transfer from RTOs toward local firms forms technological foundations and develops the ability to enhance the competitiveness of firms. Better understanding of factors influencing process of technology transfer helps RTOs and local firms prioritize and manage their resources in an effective and efficient way to maximize the success of technology transfer. This paper aims to identify important effective factors in technology transfer from Iranian RTOs and provides a comprehensive model, which indicate the interactions of these factors. In this regard, first, research background is reviewed and Cummings and Teng’s model (2003 [Cummings, J. L., & Teng, B.-S. (2003. Transferring R&D knowledge: The key factors affecting knowledge transfer success. Journal of Engineering and Technology Management, 20(1-2, 39-68.] was selected as the basic model in this study and it was modified through suggesting new factors identified from literature of inter-organizational knowledge and technology transfer and finally a Delphi method was applied for validation of modified model. Then, research conducted used Interpretive Structural Modeling (ISM to evaluate the relationship between the factors of final proposed model. Results indicate that there were twelve factors influencing on technology transfer process from Iranian RTOs to local firms and also the intensity of absorption capability in transferee could influence on the intensity of desorption capability in transferor.

  17. Factor Analytic Approach to Transitive Text Mining using Medline Descriptors

    Science.gov (United States)

    Stegmann, J.; Grohmann, G.

    Matrix decomposition methods were applied to examples of noninteractive literature sets sharing implicit relations. Document-by-term matrices were created from downloaded PubMed literature sets, the terms being the Medical Subject Headings (MeSH descriptors) assigned to the documents. The loadings of the factors derived from singular value or eigenvalue matrix decomposition were sorted according to absolute values and subsequently inspected for positions of terms relevant to the discovery of hidden connections. It was found that only a small number of factors had to be screened to find key terms in close neighbourhood, being separated by a small number of terms only.

  18. An immunologic approach to induction of epidermal growth factor deficiency

    DEFF Research Database (Denmark)

    Raaberg, Lasse; Nexø, Ebba; Poulsen, Steen Seier

    1995-01-01

    Epidermal growth factor (EGF) in pharmacologic doses is able to induce growth and development in the fetus and the newborn. To investigate the opposite situation, the effects of insufficient amounts of EGF during development, we wanted to establish an in vivo model with a state of EGF deficiency....

  19. The Status of Cognitive Psychology Journals: An Impact Factor Approach

    Science.gov (United States)

    Togia, Aspasia

    2013-01-01

    The purpose of this study was to examine the impact factor of cognitive psychology journals indexed in the Science and Social Sciences edition of "Journal Citation Reports" ("JCR") database over a period of 10 consecutive years. Cognitive psychology journals were indexed in 11 different subject categories of the database. Their mean impact factor…

  20. In Vitro Approaches to Evaluation of Sun Protectin Factor

    Czech Academy of Sciences Publication Activity Database

    Bendová, H.; Akrman, J.; Krejčí, A.; Kubáč, L.; Jírová, D.; Kejlová, K.; Kolářová, H.; Brabec, Marek; Malý, M.

    2007-01-01

    Roč. 21, č. 7 (2007), s. 1268-1275 ISSN 0887-2333 Source of funding: V - iné verejné zdroje Keywords : sunscreens * in vitro * SPF * nonparametric model Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.193, year: 2007

  1. A sensitivity analysis approach to identify key environmental performance factors

    OpenAIRE

    Yu, Xi; Sekhari, Aicha; Nongaillard, Antoine; Bouras, Abdelaziz; Yu, Suiran

    2014-01-01

    Life cycle assessment (LCA) is widely used in design phase to reduce the product's environmental impacts through the whole product life cycle (PLC) during the last two decades. The traditional LCA is restricted to assessing the environmental impacts of a product and the results cannot reflect the effects of changes within the life cycle. In order to improve the quality of ecodesign, it is a growing need to develop an approach which can reflect the changes between the design parameters and pro...

  2. Non-viral generation of marmoset monkey iPS cells by a six-factor-in-one-vector approach.

    Directory of Open Access Journals (Sweden)

    Katharina Debowski

    Full Text Available Groundbreaking studies showed that differentiated somatic cells of mouse and human origin could be reverted to a stable pluripotent state by the ectopic expression of only four proteins. The resulting pluripotent cells, called induced pluripotent stem (iPS cells, could be an alternative to embryonic stem cells, which are under continuous ethical debate. Hence, iPS cell-derived functional cells such as neurons may become the key for an effective treatment of currently incurable degenerative diseases. However, besides the requirement of efficacy testing of the therapy also its long-term safety needs to be carefully evaluated in settings mirroring the clinical situation in an optimal way. In this context, we chose the long-lived common marmoset monkey (Callithrix jacchus as a non-human primate species to generate iPS cells. The marmoset monkey is frequently used in biomedical research and is gaining more and more preclinical relevance due to the increasing number of disease models. Here, we describe, to our knowledge, the first-time generation of marmoset monkey iPS cells from postnatal skin fibroblasts by non-viral means. We used the transposon-based, fully reversible piggyback system. We cloned the marmoset monkey reprogramming factors and established robust and reproducible reprogramming protocols with a six-factor-in-one-construct approach. We generated six individual iPS cell lines and characterized them in comparison with marmoset monkey embryonic stem cells. The generated iPS cells are morphologically indistinguishable from marmoset ES cells. The iPS cells are fully reprogrammed as demonstrated by differentiation assays, pluripotency marker expression and transcriptome analysis. They are stable for numerous passages (more than 80 and exhibit euploidy. In summary, we have established efficient non-viral reprogramming protocols for the derivation of stable marmoset monkey iPS cells, which can be used to develop and test cell replacement

  3. Generational Approach to Factors Influencing Career Choice in Accounting

    Directory of Open Access Journals (Sweden)

    Jony Hsiao

    Full Text Available ABSTRACT This research aims to grasp which factors influence the generation Y to choose accounting as its career. A significant decline in the number of candidates willing to pursue a career as accountant has been observed abroad - USA, Australia, and Japan. However, in other countries - Brazil, Singapore, and Hong Kong - the opposite has been observed. Another issue is the decline in educational qualification of those pursuing an accounting career, contributing in a way that many talented students change their career choice. This may be explained by the fact that people tend to believe accounting is an exact science, full of calculations, boring, and not very creative, bringing an unbalance between the traits an individual should have according to the job market and those perceived by society. In order to give a contribution to literature concerning the factors that influence the generation Y in its career choice, a goal of this research was conducting an exploratory study where some hypotheses were formulated to support the discussion. We used Mannheim's Generational Theory and the literature on career choice. Data collection was carried out using a questionnaire, based on Schwartz's Portrait Value Questionnaire and Germeijs and Verschueren's Student Choice Task Inventory, adapted through focus group interview. Data were fully collected online and the sample consisted of 665 subjects. The results showed that people who chose accounting as their career were influenced by factors such as creativity, independence, challenging and dynamic environment, job security, money-making, job availability, and other significant people - friends and teachers. The subjects were not influenced by social factors, such as working with people and making contributions to society and family. They wish for more autonomy, creativity, and flexibility at work, and people still care about job security and money-making.

  4. Approaching Safety through Quality: Factors Influencing College Student Perceptions.

    Science.gov (United States)

    Ramaswamy, S K; Mosher, G A

    2016-04-01

    Quality management practices have been identified by previous literature as a factor that could potentially reduce the level of safety incidents and hazards in agricultural work environments. The present study used multivariate analysis to examine the effect of independent variables such as quality and safety awareness, work experience, safety and quality management experience, and the perceived importance of safety and quality on the role of quality management practices as a mitigating factor for safety hazards and incidents in agriculture. Variables were measured on a five-point scale using a survey questionnaire. Data were collected from approximately 900 undergraduates enrolled in the College of Agriculture and Life Sciences at a large land grant university in the U.S. The level of student work experience and student perceptions of the importance of quality explained a significant amount of the variance in student views of quality management practices as a mitigating factor for safety hazards and incidents. The findings of this study provide further evidence for using quality management practices as a basis for safety interventions targeted at the agricultural workforce.

  5. Moving Aerospace Structural Design Practice to a Load and Resistance Factor Approach

    Science.gov (United States)

    Larsen, Curtis E.; Raju, Ivatury S.

    2016-01-01

    Aerospace structures are traditionally designed using the factor of safety (FOS) approach. The limit load on the structure is determined and the structure is then designed for FOS times the limit load - the ultimate load. Probabilistic approaches utilize distributions for loads and strengths. Failures are predicted to occur in the region of intersection of the two distributions. The load and resistance factor design (LRFD) approach judiciously combines these two approaches by intensive calibration studies on loads and strength to result in structures that are efficient and reliable. This paper discusses these three approaches.

  6. A systems biology approach to transcription factor binding site prediction.

    Directory of Open Access Journals (Sweden)

    Xiang Zhou

    2010-03-01

    Full Text Available The elucidation of mammalian transcriptional regulatory networks holds great promise for both basic and translational research and remains one the greatest challenges to systems biology. Recent reverse engineering methods deduce regulatory interactions from large-scale mRNA expression profiles and cross-species conserved regulatory regions in DNA. Technical challenges faced by these methods include distinguishing between direct and indirect interactions, associating transcription regulators with predicted transcription factor binding sites (TFBSs, identifying non-linearly conserved binding sites across species, and providing realistic accuracy estimates.We address these challenges by closely integrating proven methods for regulatory network reverse engineering from mRNA expression data, linearly and non-linearly conserved regulatory region discovery, and TFBS evaluation and discovery. Using an extensive test set of high-likelihood interactions, which we collected in order to provide realistic prediction-accuracy estimates, we show that a careful integration of these methods leads to significant improvements in prediction accuracy. To verify our methods, we biochemically validated TFBS predictions made for both transcription factors (TFs and co-factors; we validated binding site predictions made using a known E2F1 DNA-binding motif on E2F1 predicted promoter targets, known E2F1 and JUND motifs on JUND predicted promoter targets, and a de novo discovered motif for BCL6 on BCL6 predicted promoter targets. Finally, to demonstrate accuracy of prediction using an external dataset, we showed that sites matching predicted motifs for ZNF263 are significantly enriched in recent ZNF263 ChIP-seq data.Using an integrative framework, we were able to address technical challenges faced by state of the art network reverse engineering methods, leading to significant improvement in direct-interaction detection and TFBS-discovery accuracy. We estimated the accuracy

  7. Factors associated with media use among adolescents: a multilevel approach.

    Science.gov (United States)

    Garcia-Continente, Xavier; Pérez-Giménez, Anna; Espelt, Albert; Nebot Adell, Manel

    2014-02-01

    During the last few years, several studies have reported a high screen time use among adolescents that can be related to negative health effects. The aims of this study were to describe screen time use among secondary school students and to identify individual- and school-level factors associated with media use. A cross-sectional study based on a self-reported questionnaire was performed among a representative sample of 2675 secondary school students (13-19 years old). Adolescents reported the amount of time spent viewing television, playing videogames and using the computer as well as other health-related behaviours and attitudes. Multilevel analysis was carried out and prevalence ratios were calculated to determine the association between media use and related factors. Around 50% of the students reported watching television for ≥2 h/day during weekdays. Boys reported playing videogames for ≥2 h/weekday much more often than girls (14.6 and 1.5%, respectively). 68.2% of boys and 61.7% of girls reported using the computer for ≥2 h/weekday. In the multilevel analysis, the main factors associated with screen-related sedentary behaviours were attending schools from a low socio-economic status neighbourhood, eating unhealthy food and not reading books frequently. The prevalence of adolescents reporting an excessive use of media devices is high, especially among students attending schools from deprived areas. Interventions to reduce screen time among adolescents may be necessary to reduce the risk of some metabolic and cardiovascular diseases such as being overweight and obesity in late adolescence or early adulthood.

  8. Statistical optimization of thermo-alkali stable xylanase production from Bacillus tequilensis strain ARMATI

    Directory of Open Access Journals (Sweden)

    Ameer Khusro

    2016-07-01

    Conclusions: The cellulase-free xylanase showed an alkali-tolerant and thermo-stable property with potentially applicable nature at industrial scale. This statistical approach established a major contribution in enzyme production from the isolate by optimizing independent factors and represents a first reference on the enhanced production of thermo-alkali stable cellulase-free xylanase from B. tequilensis.

  9. A statistical mechanics approach to the factorization problem

    OpenAIRE

    Henelius, P.; Girvin, S.

    2011-01-01

    We map the problem of finding the prime factors of an integer to the statistical physics problem of finding the ground state of a long-range Ising-like model. As in the strongly disordered Newman-Stein (NS) spin-glass model, the bond distribution is exponentially wide and grows with system size, but unlike the NS model we find that it is not wide enough for a greedy algorithm to be applicable. On the other hand, we also find that the frustration and exponential width of the bond distribution ...

  10. A theoretical approach to the re-suspension factor

    Directory of Open Access Journals (Sweden)

    Magnoni M.

    2012-04-01

    Full Text Available The atmospheric re-suspension of radionuclides is a well-known phenomenon that consists in the re-injection into the atmosphere of previously deposited radioactivity. The process is driven by the action of wind on surfaces and can act as an additional source of radiation exposure by inhalation, after the deposition has finished. It is thus defined as the re-suspension factor, a parameter K generally considered as a time depending function and defined as the ratio of Ca, the volumetric air activity concentration (Bq m−3 and I0 (Bq m−2, the radioactivity deposition at time zero. The re-suspension factor concept is very useful in radioprotection in order to estimate the inhalation of radionuclides re-suspended from contaminated surfaces when direct atmospheric measurements are lacking or difficult to perform. However, the choice of the proper values of K is usually not a simple task, being quite site-specific and related to the meteorological, géomorphologie and environmental characteristics of the area to be studied. Moreover, several investigations showed clearly that the values of K are a decreasing function of time. For that reason, K values span several orders of magnitude: typical values in the range 10−5–10−10 m−1 are reported in literature for different environmental conditions and time elapsed since the deposition event. The current available models for the re-suspension factor are based on empirical formulas whose parameters are highly site dependent and cannot easily be related to some physical quantity. In this paper a simple physical model for the re-suspension factor is proposed and tested with available environmental radioactivity data (137Cs, collected since 1986 (Chernobyl fallout. The new model not only allows a satisfactory description of the experimental data like even the current empirical models do, but it is also able to connect the K values to quantities with a physical meaning (such as, for example a diffusion

  11. DETERMINANT EROSION FACTORS FOR PENSION ROMANIAN SYSTEM - A STATISTICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Ana-Gabriela BABUCEA

    2010-09-01

    Full Text Available The demographical evolutions of the last 20 years, the changes in the Romanian economy and society influenced one special category which is the retired people. As inactive population, retired people represents an important category, their numbers being rather big in comparison with the employed population, practical the contributors at the pensions fund. In 2010, the stat has serious problems with paying pensions. The evolution of this category of people is the subject of this paper. We try to identify the factors that had negative influence upon the pension Romanian system. The reference years that we considered are 1990-2009.

  12. Dietary Patterns Derived Using Exploratory and Confirmatory Factor Analysis are Stable and Generalizable Across Race, Region, and Gender Subgroups in the REGARDS Study

    Science.gov (United States)

    Judd, Suzanne E.; Letter, Abraham J.; Shikany, James M.; Roth, David L.; Newby, P. K.

    2015-01-01

    Background: Examining diet as a whole using dietary patterns as exposures is a complementary method to using single food or nutrients in studies of diet and disease, but the generalizability of intake patterns across race, region, and gender in the United States has not been established. Objective: To employ rigorous statistical analysis to empirically derive dietary patterns in a large bi-racial, geographically diverse population and examine whether results are stable across population subgroups. Design: The present analysis utilized data from 21,636 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who completed the Block 98 food frequency questionnaire. We employed exploratory factor analysis and confirmatory factor analyses on 56 different food groups iteratively and examined differences by race, region, and sex to determine the optimal factor solution in our sample. Results: Five dietary patterns emerged: the “Convenience” pattern was characterized by mixed dishes; the “Plant-based” pattern by fruits, vegetables, and fish; the “Sweets/Fats” pattern by sweet snacks, desserts, and fats and oils; the “Southern” pattern by fried foods, organ meat, and sweetened beverages; and the “Alcohol/Salads” pattern by beer, wine, liquor, and salads. Differences were most pronounced in the Southern pattern with black participants, those residing in the Southeast, and participants not completing high school having the highest scores. Conclusion: Five meaningful dietary patterns emerged in the REGARDS study and showed strong congruence across race, sex, and region. Future research will examine associations between these patterns and health outcomes to better understand racial disparities in disease and inform prevention efforts. PMID:25988129

  13. Recent advances in the management of chronic stable angina II. Anti-ischemic therapy, options for refractory angina, risk factor reduction, and revascularization

    Directory of Open Access Journals (Sweden)

    Richard Kones

    2010-08-01

    Full Text Available Richard KonesThe Cardiometabolic Research Institute, Houston, Texas, USAAbstract: The objectives in treating angina are relief of pain and prevention of disease ­progression through risk reduction. Mechanisms, indications, clinical forms, doses, and side effects of the traditional antianginal agents – nitrates, ß-blockers, and calcium channel ­blockers – are reviewed. A number of patients have contraindications or remain unrelieved from anginal discomfort with these drugs. Among newer alternatives, ranolazine, recently approved in the United States, indirectly prevents the intracellular calcium overload involved in cardiac ischemia and is a welcome addition to available treatments. None, however, are disease-modifying agents. Two options for refractory angina, enhanced external counterpulsation and spinal cord stimulation (SCS, are presented in detail. They are both well-studied and are effective means of treating at least some patients with this perplexing form of angina. Traditional modifiable risk factors for coronary artery disease (CAD – smoking, hypertension, dyslipidemia, ­diabetes, and obesity – account for most of the population-attributable risk. Individual therapy of high-risk patients differs from population-wide efforts to prevent risk factors from appearing or reducing their severity, in order to lower the national burden of disease. Current American College of Cardiology/American Heart Association guidelines to lower risk in patients with chronic angina are reviewed. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE trial showed that in patients with stable angina, optimal medical therapy alone and percutaneous coronary intervention (PCI with medical therapy were equal in preventing myocardial infarction and death. The integration of COURAGE results into current practice is discussed. For patients who are unstable, with very high risk, with left main coronary artery lesions, in

  14. Omics Approach to Identify Factors Involved in Brassica Disease Resistance.

    Science.gov (United States)

    Francisco, Marta; Soengas, Pilar; Velasco, Pablo; Bhadauria, Vijai; Cartea, Maria E; Rodríguez, Victor M

    2016-01-01

    Understanding plant's defense mechanisms and their response to biotic stresses is of fundamental meaning for the development of resistant crop varieties and more productive agriculture. The Brassica genus involves a large variety of economically important species and cultivars used as vegetable source, oilseeds, forage and ornamental. Damage caused by pathogens attack affects negatively various aspects of plant growth, development, and crop productivity. Over the last few decades, advances in plant physiology, genetics, and molecular biology have greatly improved our understanding of plant responses to biotic stress conditions. In this regard, various 'omics' technologies enable qualitative and quantitative monitoring of the abundance of various biological molecules in a high-throughput manner, and thus allow determination of their variation between different biological states on a genomic scale. In this review, we have described advances in 'omic' tools (genomics, transcriptomics, proteomics and metabolomics) in the view of conventional and modern approaches being used to elucidate the molecular mechanisms that underlie Brassica disease resistance.

  15. HDL in sepsis - risk factor and therapeutic approach

    Directory of Open Access Journals (Sweden)

    Emily E Morin

    2015-10-01

    Full Text Available High-density lipoprotein (HDL is a key component of circulating blood and plays essential roles in regulation of vascular endothelial function and immunity. Clinical data demonstrate that HDL levels drop by 40-70% in septic patients, which is associated with a poor prognosis. Experimental studies using Apolipoprotein A-I (ApoAI null mice as an HDL deficient model showed that mice lacking HDL are susceptible to septic death, and overexpressing ApoAI in mice to increase HDL levels protects against septic death. These clinical and animal studies support our hypothesis that a decrease in HDL level is a risk factor for sepsis, and raising circulating HDL levels may provide an efficient therapy for sepsis. In this review, we discuss the roles of HDL in sepsis and summarize the efforts of using synthetic HDL as a potential therapy for sepsis.

  16. Factors Mediating the Interactions between Adviser and Advisee during the Master's Thesis Project: A Quantitative Approach

    Science.gov (United States)

    Rodrigues Jr., Jose Florencio; Lehmann, Angela Valeria Levay; Fleith, Denise De Souza

    2005-01-01

    Building on previous studies centred on the interaction between adviser and advisee in masters thesis projects, in which a qualitative approach was used, the present study uses factor analysis to identify the factors that determine either a successful or unsuccessful outcome for the masters thesis project. There were five factors relating to the…

  17. An integrated approach to rotorcraft human factors research

    Science.gov (United States)

    Hart, Sandra G.; Hartzell, E. James; Voorhees, James W.; Bucher, Nancy M.; Shively, R. Jay

    1988-01-01

    As the potential of civil and military helicopters has increased, more complex and demanding missions in increasingly hostile environments have been required. Users, designers, and manufacturers have an urgent need for information about human behavior and function to create systems that take advantage of human capabilities, without overloading them. Because there is a large gap between what is known about human behavior and the information needed to predict pilot workload and performance in the complex missions projected for pilots of advanced helicopters, Army and NASA scientists are actively engaged in Human Factors Research at Ames. The research ranges from laboratory experiments to computational modeling, simulation evaluation, and inflight testing. Information obtained in highly controlled but simpler environments generates predictions which can be tested in more realistic situations. These results are used, in turn, to refine theoretical models, provide the focus for subsequent research, and ensure operational relevance, while maintaining predictive advantages. The advantages and disadvantages of each type of research are described along with examples of experimental results.

  18. Factors Influencing Sedentary Behaviour in Older Adults: An Ecological Approach

    Directory of Open Access Journals (Sweden)

    Patricia Weir

    2016-08-01

    Full Text Available Sedentary behaviour is negatively associated with several health outcomes and is particularly problematic among older adults. Knowledge translation tools and public health promotion strategies are needed; however, little evidence is available to inform framing of such tools or development of intervention programs. The aim of the present study was to use data on the perceptions of sedentary time and the programs or supports older adults identify as important for reducing their sedentary time, to inform knowledge translation strategies targeting this population. Focus groups were conducted with four groups of older adults (n = 26 at local seniors' centres (Ontario, Canada. Participants were 74 ± 8.5 years old and were engaging in both sedentary and physical activities in a social environment. Using the Ecological Model for sedentary time in adults, we categorized data into leisure time, household, transport and occupation domains. Intrinsic and extrinsic factors that worked to either discourage or promote sedentary behaviour were identified. Drawing on both groupings of data, results were synthesized to inform public health strategies on appropriate messaging and better uptake of programming and guidelines. For example, successful programs developed on the topic will need to include a social component and a mentally stimulating component, as these were identified as critical for enjoyment and motivation. It was clear from this analysis that sedentary time reduction strategies will need to consider the different domains in which older adults accumulate sedentary time.

  19. Stable isotope-based approach to validate effects of understory vegetation on shallow soil water movement in a Japanese cypress plantation

    Science.gov (United States)

    Sakashita, W.; Onda, Y.; Boutefnouchet, M. R.; Kato, H.; Gomi, T.

    2017-12-01

    Evapotranspiration is an important controlling factor of the hydrological cycle in forested watershed. In general, the evapotranspiration is partitioned into three components (evaporation, transpiration, and interception). In a Japanese cypress plantation, our previous work using hydrometric method revealed that total evapotranspiration rate was 47.5% of the total rainfall amount during the growing season. This research also provided the contribution rates of three evapotranspiration components. Our previous study reported the difference of forest floor evaporation between pre-thinning and post-thinning periods (pre-thinning: Nov 2010-Oct 2011; post-thinning: Nov 2011-Oct 2012), indicating that a significant change appeared in the evaporation flux after the thinning. To examine the long-term changes of evapotranspiration, we have to consider the influence of increased understory vegetation. However, hydrometric-based method using such as weighting lysimeter is sensitive to vegetation conditions inside and outside lysimeter. This disadvantage makes it difficult to evaluate the contribution rates of each evapotranspiration components. In this study, we focus on the isotope-based method to obtain each flux of evapotranspiration under the condition including understory vegetation. Our study site is Mt. Karasawa, Tochigi Prefecture, in central Japan (139°36'E, 36°22'N; 198 m a.s.l.), and we prepare both sparse and dense areas of understory vegetation. In these two plots, we collect soil water samples from shallow depth profiles after various intensity precipitation events. Throughfall and understory-intercepted water are also obtained. Stable water isotope measurements of these samples may provide information about (a) effects of understory vegetation on shallow soil water movement and (b) interception flux of understory vegetation. In this paper, we report the results and interpretations of our measurements.

  20. DUI recidivism by intervention adherence: a multiple risk factor approach.

    Science.gov (United States)

    Robertson, Angela; Gardner, Sheena; Walker, Courtney S; Tatch, Andrew

    2016-09-01

    Multi-component impaired driving interventions can reduce driving under the influence (DUI) recidivism rates; however, outcomes are better for those who complete the interventions and are adherent with program expectations. Research is needed to examine the differences between DUI offenders who are adherent vs. non-adherent to intervention efforts. The current study utilized a multi-risk factor model to predict recidivism among first-time DUI offenders enrolled in an intervention program. Differences between offenders who were adherent (including program completion) vs. non-adherent with the intervention were examined. Using data from the Mississippi Alcohol Safety Education Program (MASEP) and state administrative records, the current study examined both recidivism rates and rates of intervention completion for all individuals enrolled in the program. The sample was predominantly White (58.8%) and male (80.2%). Individuals who were adherent with the intervention were significantly less likely to recidivate within 3 years. Prior traffic or other criminal violations positively predicted recidivism rates. The likelihood of recidivism varied, with males, African Americans, and younger individuals with less education at greater risk of recidivism. Adherence with the intervention was more common for African American and older participants. The MASEP participants who were adherent with the intervention were significantly less likely to recidivate than those who were non-adherent. However, variance in the multi-component intervention completion rates suggests that the program resonates better with specific population subsets. We argue for researchers and policymakers to further explore how specific population subsets react to varying intervention programs to maximize efforts to reduce impaired driving.

  1. Factor analytical approaches for evaluating groundwater trace element chemistry data

    International Nuclear Information System (INIS)

    Farnham, I.M.; Johannesson, K.H.; Singh, A.K.; Hodge, V.F.; Stetzenbach, K.J.

    2003-01-01

    The multivariate statistical techniques principal component analysis (PCA), Q-mode factor analysis (QFA), and correspondence analysis (CA) were applied to a dataset containing trace element concentrations in groundwater samples collected from a number of wells located downgradient from the potential nuclear waste repository at Yucca Mountain, Nevada. PCA results reflect the similarities in the concentrations of trace elements in the water samples resulting from different geochemical processes. QFA results reflect similarities in the trace element compositions, whereas CA reflects similarities in the trace elements that are dominant in the waters relative to all other groundwater samples included in the dataset. These differences are mainly due to the ways in which data are preprocessed by each of the three methods. The highly concentrated, and thus possibly more mature (i.e. older), groundwaters are separated from the more dilute waters using principal component 1 (PC 1). PC 2, as well as dimension 1 of the CA results, describe differences in the trace element chemistry of the groundwaters resulting from the different aquifer materials through which they have flowed. Groundwaters thought to be representative of those flowing through an aquifer composed dominantly of volcanic rocks are characterized by elevated concentrations of Li, Be, Ge, Rb, Cs, and Ba, whereas those associated with an aquifer dominated by carbonate rocks exhibit greater concentrations of Ti, Ni, Sr, Rh, and Bi. PC 3, and to a lesser extent dimension 2 of the CA results, show a strong monotonic relationship with the percentage of As(III) in the groundwater suggesting that these multivariate statistical results reflect, in a qualitative sense, the oxidizing/reducing conditions within the groundwater. Groundwaters that are relatively more reducing exhibit greater concentrations of Mn, Cs, Co, Ba, Rb, and Be, and those that are more oxidizing are characterized by greater concentrations of V, Cr, Ga

  2. A holistic approach combining factor analysis, positive matrix factorization, and chemical mass balance applied to receptor modeling.

    Science.gov (United States)

    Selvaraju, N; Pushpavanam, S; Anu, N

    2013-12-01

    Rapid urbanization and population growth resulted in severe deterioration of air quality in most of the major cities in India. Therefore, it is essential to ascertain the contribution of various sources of air pollution to enable us to determine effective control policies. The present work focuses on the holistic approach of combining factor analysis (FA), positive matrix factorization (PMF), and chemical mass balance (CMB) for receptor modeling in order to identify the sources and their contributions in air quality studies. Insight from the emission inventory was used to remove subjectivity in source identification. Each approach has its own limitations. Factor analysis can identify qualitatively a minimal set of important factors which can account for the variations in the measured data. This step uses information from emission inventory to qualitatively match source profiles with factor loadings. This signifies the identification of dominant sources through factors. PMF gives source profiles and source contributions from the entire receptor data matrix. The data from FA is applied for rank reduction in PMF. Whenever multiple solutions exist, emission inventory identifies source profiles uniquely, so that they have a physical relevance. CMB identifies the source contributions obtained from FA and PMF. The novel approach proposed here overcomes the limitations of the individual methods in a synergistic way. The adopted methodology is found valid for a synthetic data and also the data of field study.

  3. Numerical Evaluation of Stress Intensity Factors (Ki) J-Integral Approach

    National Research Council Canada - National Science Library

    Riveros, Guillermo A

    2006-01-01

    The purpose of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to describe the numerical evaluation of the stress intensity factors using the J-integral approach (Rice 1968a, 1968b...

  4. Human ciliary neurotrophic factor-overexpressing stable bone marrow stromal cells in the treatment of a rat model of traumatic spinal cord injury.

    Science.gov (United States)

    Abbaszadeh, Hojjat-Allah; Tiraihi, Taki; Noori-Zadeh, Ali; Delshad, Ali Reza; Sadeghizade, Majid; Taheri, Taher

    2015-07-01

    Traumatic injury to the central nervous system (CNS) often causes motor dysfunctions. However, because of the CNS complexity and variability in the clinical presentations, efforts to repair damaged CNS tissue and restoring its functions are particularly demanding. On the other hand, recent progress in the regenerative therapy field have led to novel approaches for the treatment of traumatic CNS injury and renewed hopes to overcome the obstacles. It appears that the balance between neurite re-growth-inhibiting and neurite re-growth-inducing molecules determines the axonal re-growth fate. Neurotrophic factors can tilt this balance and indeed promote cell survival and axonal re-growth over neurodegeneration. One of the promising neurotrophic factors in this field is ciliary neurotrophic factor (CNTF). We transfected rat bone marrow stromal cells with a mammalian expression vector-inserted human CNTF gene through the use of a non-viral method to prepare human CNTF-overexpressing stem cells under ex vivo conditions. We transplanted these modified cells to the rat model of spinal cord traumatic injury to explore functional recovery after contusion induction. Our data from immunocytochemistry and behavioral tests showed that such cells can act as a powerful potential approach to treat traumatic CNS injuries because these modified cells improved the behavioral test scores in the rat model of spinal cord injury. CNTF-overexpressing bone marrow stromal cells can ameliorate spinal cord traumatic injury and can be used in the treatment of traumatic CNS injuries in the near future. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  5. Do we need sustainability as a new approach in human factors and ergonomics?

    Science.gov (United States)

    Zink, Klaus J; Fischer, Klaus

    2013-01-01

    The International Ergonomics Association Technical Committee 'Human Factors and Sustainable Development' was established to contribute to a broad discourse about opportunities and risks resulting from current societal 'mega-trends' and their impacts on the interactions among humans and other elements of a system, e.g. in work systems. This paper focuses on the underlying key issues: how do the sustainability paradigm and human factors/ergonomics interplay and interact, and is sustainability necessary as a new approach for our discipline? Based on a discussion of the sustainability concept, some general principles for designing new and enhancing existent approaches of human factors and ergonomics regarding their orientation towards sustainability are proposed. The increasing profile of sustainability on the international stage presents new opportunities for human factors/ergonomics. Positioning of the sustainability paradigm within human factors/ergonomics is discussed. Approaches to incorporating sustainability in the design of work systems are considered.

  6. Low paraoxonase 1 arylesterase activity and high von Willebrand factor levels are associated with severe coronary atherosclerosis in patients with non-diabetic stable coronary artery disease.

    Science.gov (United States)

    Ding, Jieying; Chen, Qizhi; Zhuang, Xing; Feng, Zhilei; Xu, Lili; Chen, Fuxiang

    2014-11-25

    Paraoxonase 1 (PON1) activity and von Willebrand factor (VWF) release are associated with lesion initiation in atherosclerosis. Diabetes can complicate coronary artery disease (CAD) due to the production of advanced glycation end products. This study evaluated PON1 activity and VWF levels in non-post-acute coronary syndrome, stable CAD (SCAD) patients without diabetes. Non-diabetic SCAD patients and patients experiencing acute stress periods were selected (n=130). Forty-seven cases with normal coronary angiography and 50 healthy individuals served as controls. The non-diabetic SCAD group was then stratified into single-vessel lesions, multiple-vessel lesions, and mild or severe luminal stenosis according to the number and the degree of luminal stenoses. Serum PON1 paraoxonase and arylesterase activities, and plasma VWF levels were measured, as well as serum total cholesterol, total triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and apolipoprotein A1. PON1 arylesterase activity was detected with an ordinary chemistry system using a novel phenylacetate derivative. Both PON1 paraoxonase and arylesterase were lower in the non-diabetic SCAD group, but VWF levels were higher (versus controls, all Pparaoxonase activity (OR=0.991), PON1 arylesterase activity (OR=0.981), and VWF (OR 2.854) influenced SCAD in multiple logistic regression. Decreased PON1 arylesterase activity and increased VWF levels were associated with severe atherosclerosis in non-diabetic SCAD patients. We also observed a slight negative correlation between VWF and PON1 paraoxonase/arylesterase. PON1 and VWF are detectable markers that may predict the severity of stenoses, ideally facilitating a non-diabetic SCAD diagnosis before the sudden onset of life-threatening symptoms.

  7. Stochastic Discount Factor Approach to International Risk-Sharing:A Robustness Check of the Bilateral Setting

    NARCIS (Netherlands)

    Hadzi-Vaskov, M.; Kool, C.J.M.

    2007-01-01

    This paper presents a robustness check of the stochastic discount factor approach to international (bilateral) risk-sharing given in Brandt, Cochrane, and Santa-Clara (2006). We demonstrate two main inherent limitations of the bilateral SDF approach to international risk-sharing. First, the discount

  8. The Effect of Differentiation Approach Developed on Creativity of Gifted Students: Cognitive and Affective Factors

    Science.gov (United States)

    Altintas, Esra; Özdemir, Ahmet S.

    2015-01-01

    The aim of the study is to develop a differentiation approach for the mathematics education of gifted middle school students and to determine the effect of the differentiation approach on creative thinking skills of gifted students based on both cognitive and affective factors. In this context, the answer to the following question was searched:…

  9. Factors Contributing to Changes in a Deep Approach to Learning in Different Learning Environments

    Science.gov (United States)

    Postareff, Liisa; Parpala, Anna; Lindblom-Ylänne, Sari

    2015-01-01

    The study explored factors explaining changes in a deep approach to learning. The data consisted of interviews with 12 students from four Bachelor-level courses representing different disciplines. We analysed and compared descriptions of students whose deep approach either increased, decreased or remained relatively unchanged during their courses.…

  10. Origin of halides (Cl- and Br-) and of their stable isotopes (d37Cl and d81Br) at the Tournemire URL (France) - Experimental and numerical approach

    Science.gov (United States)

    Bachir-Bey, Nassim; Matray, Jean-Michel

    2014-05-01

    This work is part of research conducted by the Institute of Radiological and Nuclear Safety (IRSN) on the geological disposal of High-Level and Intermediate-Level Long-Lived (HL-ILLL) radioactive waste in deep clayrocks. In France, the choice of the potential host rock for the geological storage is focused on the Callovian-Oxfordian (COx) of Meuse/Haute-Marne from its low permeability, capacity for self- sealing, high sorption and ability to radionuclide (RN) transport by diffusion. IRSN, which plays an expert role for ASN has its own underground research laboratory in a clayrock which has strong analogies to the COx. This is the Toarcian/Domerian clayrock located at Tournemire in southern Aveyron in France. The purpose of this study was to assess the transfer of RN in the Tournemire clayrock through the study of halides contents and of their stable isotopes (Cl-, Br-, Cl-/Br-, d37Cl, d81Br). The approach used was multiple and consisted for halides to: 1) Assess their stock in different fractions of the rock by applying several techniques including i) alkaline fusion for their total stock, ii) leaching to access their stock in porewater and to mineral phases sensitive to dissolution iii) cubic diffusion for their stock in porewater, 2) Get their diffusive transport parameters of a selection of samples from the upper Toarcian by cubic diffusion experiments modelled using the Hytec transport code developed by Mines ParisTech and 3) Model their transport after palaeohydrogeological known changes of the Tournemire massif. The experimental approach, conducted at the LAME lab, did not lead to an operational protocol for the alkaline fusion due to an incomplete rock dissolution. Leaching was used to characterize the concentrations of halides in the fractions of pore water and of minerals sensitive to dissolution. The results show levels of halides much higher than those of pore water with very low Cl/Br ratios likely resulting from the dissolution of mineral species. The

  11. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  12. The Combination of Fosfomycin, Metronidazole, and Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor is Stable in vitro and Has Maintained Antibacterial Activity

    DEFF Research Database (Denmark)

    Fonnes, Siv; Holzknecht, Barbara Juliane; Gasbjerg, Lærke Smidt

    2017-01-01

    with the effect of the individual antibacterial agents. METHODS: The drugs were mixed to an aqueous solution. Basic chemical investigations of pH, precipitation, and calculated osmolarity of the drug combination were conducted. Fosfomycin and metronidazole's chemical stability was investigated using High Pressure......, was without precipitation, and had a calculated osmolarity of 293 mOsm/l. High Pressure Liquid Chromatography-Mass Spectrometry found stable concentrations of fosfomycin and metronidazole both alone and in combination during 24 h. The antibacterial effect of the drug combination solution was similar...... to the antibacterial effects of fosfomycin and metronidazole alone. CONCLUSION: The drug combination had neutral and stable pH, was iso-osmotic, and had stable concentrations during 24 h of storage. The antibacterial effect of fosfomycin and metronidazole were not altered when the drugs were mixed....

  13. Baleen as a biomonitor of mercury content and dietary history of North Atlantic Minke Whales (Balaenopetra acutorostrata): combining elemental and stable isotope approaches

    Energy Technology Data Exchange (ETDEWEB)

    Hobson, K.A.; Riget, F.F.; Outridge, P.M.; Dietz, R.; Born, E

    2004-09-20

    Baleen is an incrementally-growing tissue of balaenopteran whales which preserves relatively well over time in museums and some archeological sites, and, therefore might be useful for studies examining long-term changes of metal levels in whales. This study examined Hg and stable C and N isotopic composition of baleen plates of the North Atlantic minke whale (Balaenoptera acutorostrata), which continues to be a food source for people in Greenland and elsewhere. We compared the Hg levels and stable isotopes of major tissues (kidney, liver and muscle) with those of baleen plates to see whether baleen could be used as a biomonitor of variations of Hg intake and diet both between individuals and within individuals over time. Mercury was significantly correlated with concentrations in all tissues (kidney, liver and muscle). Stable C and N isotopes in baleen were generally similar to those of muscle, which reflects the recent (approximately one month) feeding of the whale, but in some individuals there were significant differences between baleen and muscle. Sectioning of baleen into 1 cm longitudinal increments showed that these differences were due to marked dietary shifts by some individuals over time that had been recorded in the baleen but were lost from the muscle record. Whole baleen C and N isotopes were better correlated with tissue Hg levels, suggesting that baleen may provide a more reliable indicator of long-term average diet, which in turn may be better related to Hg accumulation in tissues than the shorter-term diet record contained in muscle.

  14. An integrated graphic–taxonomic–associative approach to analyze human factors in aviation accidents

    Directory of Open Access Journals (Sweden)

    Gong Lei

    2014-04-01

    Full Text Available Human factors are critical causes of modern aviation accidents. However, existing accident analysis methods encounter limitations in addressing aviation human factors, especially in complex accident scenarios. The existing graphic approaches are effective for describing accident mechanisms within various categories of human factors, but cannot simultaneously describe inadequate human–aircraft–environment interactions and organizational deficiencies effectively, and highly depend on analysts’ skills and experiences. Moreover, the existing methods do not emphasize latent unsafe factors outside accidents. This paper focuses on the above three limitations and proposes an integrated graphic–taxonomic–associative approach. A new graphic model named accident tree (AcciTree, with a two-mode structure and a reaction-based concept, is developed for accident modeling and safety defense identification. The AcciTree model is then integrated with the well-established human factors analysis and classification system (HFACS to enhance both reliability of the graphic part and logicality of the taxonomic part for improving completeness of analysis. An associative hazard analysis technique is further put forward to extend analysis to factors outside accidents, to form extended safety requirements for proactive accident prevention. Two crash examples, a research flight demonstrator by our team and an industrial unmanned aircraft, illustrate that the integrated approach is effective for identifying more unsafe factors and safety requirements.

  15. Estimating Productivity of Software Development Using the Total Factor Productivity Approach

    Directory of Open Access Journals (Sweden)

    Machek Ondrej

    2012-11-01

    productivity measurement. In this article, we propose a model of process productivity measurement based on the total factor productivity (TFP approach commonly used in economics. In the first part of the article, we define productivity and its measurement. We also discuss the major data issues which have to be taken into consideration. Consequently, we apply the TFP approach in the domain of software engineering and we propose a TFP model of productivity assessment.

  16. Two experiments to approach the Boltzmann factor: chemical reaction and viscous flow

    International Nuclear Information System (INIS)

    Fazio, Claudio; Battaglia, Onofrio R; Guastella, Ivan

    2012-01-01

    In this paper we discuss a pedagogical approach aimed at pointing out the role played by the Boltzmann factor in describing phenomena usually perceived as regulated by different mechanisms of functioning. Experimental results regarding some aspects of a chemical reaction and of the viscous flow of some liquids are analysed and described in terms of macroscopic variables whose temperature dependence is proportional to the Boltzmann factor. A description of a workshop implementing the approach in the framework of an undergraduate course for engineering education and some preliminary results about its pedagogical relevance are then reported. (paper)

  17. Analysis of factors affecting satisfaction level on problem based learning approach using structural equation modeling

    Science.gov (United States)

    Hussain, Nur Farahin Mee; Zahid, Zalina

    2014-12-01

    Nowadays, in the job market demand, graduates are expected not only to have higher performance in academic but they must also be excellent in soft skill. Problem-Based Learning (PBL) has a number of distinct advantages as a learning method as it can deliver graduates that will be highly prized by industry. This study attempts to determine the satisfaction level of engineering students on the PBL Approach and to evaluate their determinant factors. The Structural Equation Modeling (SEM) was used to investigate how the factors of Good Teaching Scale, Clear Goals, Student Assessment and Levels of Workload affected the student satisfaction towards PBL approach.

  18. The production of stable isotopes in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Urgel, M.; Iglesias, J.; Casas, J.; Saviron, J. M.; Quintanilla, M.

    1965-07-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs.

  19. The production of stable isotopes in Spain

    International Nuclear Information System (INIS)

    Urgel, M.; Iglesias, J.; Casas, J.; Saviron, J. M.; Quintanilla, M.

    1965-01-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs

  20. An alternative approach for ζ-factor measurement using pure element nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zanaga, Daniele; Altantzis, Thomas; Sanctorum, Jonathan [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Freitag, Bert [FEI Company, Building AAE, Achtseweg Noord 5, Eindhoven (Netherlands); Bals, Sara, E-mail: sara.bals@uantwerpen.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2016-05-15

    It is very challenging to measure the chemical composition of hetero nanostructures in a reliable and quantitative manner. Here, we propose a novel and straightforward approach that can be used to quantify energy dispersive X-ray spectra acquired in a transmission electron microscope. Our method is based on a combination of electron tomography and the so-called ζ-factor technique. We will demonstrate the reliability of our approach as well as its applicability by investigating Au-Ag and Au-Pt hetero nanostructures. Given its simplicity, we expect that the method could become a new standard in the field of chemical characterization using electron microscopy. - Highlights: • A new method to determine ζ-factors for EDXS quantification is proposed. • Pure element nanoparticles are used as standards in the determination of ζ-factors. • Electron tomography is used to measure volumes in determining the ζ-factors.

  1. Importance of seagrass-mangrove continuum as feeding grounds for juvenile pink ear emperor Lethrinus lentjan in Setiu Lagoon, Malaysia: Stable isotope approach

    Science.gov (United States)

    Le, Dung Quang; Tanaka, Kentaro; Hii, Yii Siang; Sano, Yuji; Nanjo, Kusuto; Shirai, Kotaro

    2018-05-01

    The commercially important pink ear emperor fish, Lethrinus lentjan, often occurs as a juvenile in subtropical and tropical interlinked mangrove and seagrass ecosystems, but little is known about its feeding habits and habitat use. Here, we used gut contents and stable isotopic (δ13C and δ15N) ratios to determine temporal changes in food sources and foraging habits of juvenile and sub-adult fish collected in mangrove forests and seagrass beds in the Setiu Lagoon. Gut content examination identified the main food sources as crustaceans, gastropods, bivalves, and annelids. Stable isotope analysis of food sources showed marked differences between the mangroves (δ13C = -26.8 ± 2.0‰; δ15N = 4.3 ± 1.7‰) and the seagrasses (mean ± S.D. δ13C = -20.5 ± 5.5‰; δ15N = 5.8 ± 1.2‰). The isotopic composition of L. lentjan revealed that it mainly utilized seagrass-based food sources. Rainfall and the semi-diurnal tidal regimes may affect the foraging habitats of fish in the lagoon. A significant depletion of 13C related to body size was observed, suggesting that mangroves provided some benefits to sub-adult fish. In contrast, trophic position increased with fish growth, although this increase was negligible. A stable isotope mixing model confirmed that the seagrass bed constituted the main carbon source for the fish, but with an increasing contribution of mangrove prey, such as sesarmid crabs, related to fish growth. This study provided novel information on seasonal variations in feeding areas and flexible habitat use in L. lentjan in the Setiu Lagoon, which will help optimize management strategies for sustainable use and wildlife conservation.

  2. Mathematical approach for the assessment of similarity factor using a new scheme for calculating weight.

    Science.gov (United States)

    Gohel, M C; Sarvaiya, K G; Shah, A R; Brahmbhatt, B K

    2009-03-01

    The objective of the present work was to propose a method for calculating weight in the Moore and Flanner Equation. The percentage coefficient of variation in reference and test formulations at each time point was considered for calculating weight. The literature reported data are used to demonstrate applicability of the method. The advantages and applications of new approach are narrated. The results show a drop in the value of similarity factor as compared to the approach proposed in earlier work. The scientists who need high accuracy in calculation may use this approach.

  3. Approach to the human diet of the punic population of Can Marines (Ibiza. C an N stable isotope analysis on bone collagen

    Directory of Open Access Journals (Sweden)

    Domingo Carlos Salazar García

    2012-09-01

    Full Text Available We report here on the results of carbon and nitrogen stable isotope analysis on bone collagen of humans from the Punic site of Can Marines (V-IVth BC from the island of Ibiza (Spain. To date, there are few isotopic studies for this period from the Mediterranean. This article reports new isotopic data from a Western Mediterranean Punic rural settlement. The results show a terrestrial based diet with no isotopic evidence of marine or freshwater protein input, and suggest the presence of C4 resources in it.

  4. An Approach for Integrated Analysis of Human Factors in Remote Handling Maintenance

    Directory of Open Access Journals (Sweden)

    Jianwen Guo

    2016-01-01

    Full Text Available Considering dangerous environmental conditions, maintenance of radioactive equipment can be performed by remote handling maintenance (RHM system. The RHM system is a sophisticated man-machine system. Therefore, human factors analysis is an inevitable aspect considered in guaranteeing successful and safe task performance. This study proposes an approach for integrated analysis of human factors in RHM so as to make the evaluating process more practical. In the approach, indicators of accessibility, health safety, and fatigue are analyzed using virtual human simulation technologies. The human error factors in the maintenance process are analyzed using the human error probability (HEP based on the success likelihood index method- (SLIM- analytic hierarchy process (AHP. The psychological factors level of maintenance personnel is determined with an expert scoring. The human factors for the entire RHM system are then evaluated using the interval method. An application example is present, and the application results show that the approach can support the evaluation of the human factors in RHM.

  5. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  6. Factors associated with caregiver stability in permanent placements: a classification tree approach.

    Science.gov (United States)

    Proctor, Laura J; Van Dusen Randazzo, Katherine; Litrownik, Alan J; Newton, Rae R; Davis, Inger P; Villodas, Miguel

    2011-06-01

    Identify individual and environmental variables associated with caregiver stability and instability for children in diverse permanent placement types (i.e., reunification, adoption, and long-term foster care/guardianship with relatives or non-relatives), following 5 or more months in out-of-home care prior to age 4 due to substantiated maltreatment. Participants were 285 children from the Southwestern site of Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). Caregiver instability was defined as a change in primary caregiver between ages 6 and 8 years. Classification and regression tree (CART) analysis was used to identify the strongest predictors of instability from multiple variables assessed at age 6 with caregiver and child reports within the domains of neighborhood/community characteristics, caregiving environment, caregiver characteristics, and child characteristics. One out of 7, or 14% of the 285 children experienced caregiver instability in their permanent placement between ages 6 and 8. The strongest predictor of stability was whether the child had been placed in adoptive care. However, for children who were not adopted, a number of contextual factors (e.g., father involvement, expressiveness within the family) and child characteristics (e.g., intellectual functioning, externalizing problem behaviors) predicted stability and instability of permanent placements. Current findings suggest that a number of factors should be considered, in addition to placement type, if we are to understand what predicts caregiver stability and find stable permanent placements for children who have entered foster care. These factors include involvement of a father figure, family functioning, and child functioning. Adoption was supported as a desired permanent placement in terms of stability, but results suggest that other placement types can also lead to stability. In fact, with attention to providing biological parents, relative, and non-relative caregivers with

  7. Factors associated with caregiver stability in permanent placements: A Classification Tree approach

    Science.gov (United States)

    Proctor, Laura J.; Van Dusen Randazzo, Katherine; Newton, Rae R.; Davis, Inger P.; Villodas, Miguel

    2013-01-01

    Objective Identify individual and environmental variables associated with caregiver stability and instability for children in diverse permanent placement types (i.e., reunification, adoption, and long-term foster care/guardianship with relatives or non-relatives), following 5 or more months in out-of-home care prior to age 4 due to substantiated maltreatment. Methods Participants were 285 children from the Southwestern site of Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). Caregiver instability was defined as a change in primary caregiver between ages 6 and 8 years. Classification and regression tree (CART) analysis was used to identify the strongest predictors of instability from multiple variables assessed at age 6 with caregiver and child reports within the domains of neighborhood/community characteristics, caregiving environment, caregiver characteristics, and child characteristics. Results One out of 7, or 14% of the 285 children experienced caregiver instability in their permanent placement between ages 6 and 8. The strongest predictor of stability was whether the child had been placed in adoptive care. However, for children who were not adopted, a number of contextual factors (e.g., father involvement, expressiveness within the family) and child characteristics (e.g., intellectual functioning, externalizing problem behaviors) predicted stability and instability of permanent placements. Conclusions Current findings suggest that a number of factors should be considered, in addition to placement type, if we are to understand what predicts caregiver stability and find stable permanent placements for children who have entered foster care. These factors include involvement of a father figure, family functioning, and child functioning. Practice Implications Adoption was supported as a desired permanent placement in terms of stability, but results suggest that other placement types can also lead to stability. In fact, with attention to providing

  8. A pragmatic approach to estimate alpha factors for common cause failure analysis

    International Nuclear Information System (INIS)

    Hassija, Varun; Senthil Kumar, C.; Velusamy, K.

    2014-01-01

    Highlights: • Estimation of coefficients in alpha factor model for common cause analysis. • A derivation of plant specific alpha factors is demonstrated. • We examine sensitivity of common cause contribution to total system failure. • We compare beta factor and alpha factor models for various redundant configurations. • The use of alpha factors is preferable, especially for large redundant systems. - Abstract: Most of the modern technological systems are deployed with high redundancy but still they fail mainly on account of common cause failures (CCF). Various models such as Beta Factor, Multiple Greek Letter, Binomial Failure Rate and Alpha Factor exists for estimation of risk from common cause failures. Amongst all, alpha factor model is considered most suitable for high redundant systems as it arrives at common cause failure probabilities from a set of ratios of failures and the total component failure probability Q T . In the present study, alpha factor model is applied for the assessment of CCF of safety systems deployed at two nuclear power plants. A method to overcome the difficulties in estimation of the coefficients viz., alpha factors in the model, importance of deriving plant specific alpha factors and sensitivity of common cause contribution to the total system failure probability with respect to hazard imposed by various CCF events is highlighted. An approach described in NUREG/CR-5500 is extended in this study to provide more explicit guidance for a statistical approach to derive plant specific coefficients for CCF analysis especially for high redundant systems. The procedure is expected to aid regulators for independent safety assessment

  9. Mystery Written on Prescription Pads: Exploring Marketing Factors Influencing Prescription Behaviour using the AHP Approach

    Directory of Open Access Journals (Sweden)

    Hemant Bamoriya

    2012-12-01

    Full Text Available The Indian Pharma market is highly fragmented & nature of competition is intense. Further, in modern times influencing doctors’ prescription decision has become very complex as there is little systematic knowledge about factors affecting the doctors’ prescription behaviour and the weight of individual factor. This study aims to demystify this complex prescription behaviour of doctors, through examining the above mentioned factors. For this purpose, a focus group study will be followed by a quantitative study using the Analytic Hierarchy Process (AHP approach. The findings of the study will have important implications for the marketers in order to do proper allocation of their resources, to improve their promotional efficiency.

  10. A Factor Analytic and Regression Approach to Functional Age: Potential Effects of Race.

    Science.gov (United States)

    Colquitt, Alan L.; And Others

    Factor analysis and multiple regression are two major approaches used to look at functional age, which takes account of the extensive variation in the rate of physiological and psychological maturation throughout life. To examine the role of racial or cultural influences on the measurement of functional age, a battery of 12 tests concentrating on…

  11. Interpersonal Tension: A Two-Factor Approach to the POX Situation.

    Science.gov (United States)

    Gupta, Mahesh

    1985-01-01

    A theoretical explanation, in terms of a two-factor approach to a Person-Other-Issue (POX) Situation is offered, in an attempt to fill the void that exists in the face of the Heider-Newcomb controversy about POX balance. Validity and parsimony is demonstrated by applying it to some of the POX data reported in earlier studies. (Author/BL)

  12. Two Experiments to Approach the Boltzmann Factor: Chemical Reaction and Viscous Flow

    Science.gov (United States)

    Fazio, Claudio; Battaglia, Onofrio R.; Guastella, Ivan

    2012-01-01

    In this paper we discuss a pedagogical approach aimed at pointing out the role played by the Boltzmann factor in describing phenomena usually perceived as regulated by different mechanisms of functioning. Experimental results regarding some aspects of a chemical reaction and of the viscous flow of some liquids are analysed and described in terms…

  13. A combined structural dynamics approach identifies a putative switch in factor VIIa employed by tissue factor to initiate blood coagulation

    DEFF Research Database (Denmark)

    Olsen, Ole H; Rand, Kasper D; Østergaard, Henrik

    2007-01-01

    ) simulations and hydrogen/deuterium exchange (HX) mass spectrometry on free and TF-bound FVIIa. The differences in conformational dynamics from MD simulations are shown to be confined to regions of FVIIa observed to undergo structural stabilization as judged by HX experiments, especially implicating activation......Coagulation factor VIIa (FVIIa) requires tissue factor (TF) to attain full catalytic competency and to initiate blood coagulation. In this study, the mechanism by which TF allosterically activates FVIIa is investigated by a structural dynamics approach that combines molecular dynamics (MD...... stability of activation loop 3. Altogether, our findings strongly support an allosteric activation mechanism initiated by the stabilization of the Leu305{163}/Phe374{225} pair, which, in turn, stabilizes activation loop 3 and the S(1) and S(3) substrate pockets, the activation pocket, and N...

  14. Growth factor delivery-based tissue engineering: general approaches and a review of recent developments.

    Science.gov (United States)

    Lee, Kangwon; Silva, Eduardo A; Mooney, David J

    2011-02-06

    The identification and production of recombinant morphogens and growth factors that play key roles in tissue regeneration have generated much enthusiasm and numerous clinical trials, but the results of many of these trials have been largely disappointing. Interestingly, the trials that have shown benefit all contain a common denominator, the presence of a material carrier, suggesting strongly that spatio-temporal control over the location and bioactivity of factors after introduction into the body is crucial to achieve tangible therapeutic effect. Sophisticated materials systems that regulate the biological presentation of growth factors represent an attractive new generation of therapeutic agents for the treatment of a wide variety of diseases. This review provides an overview of growth factor delivery in tissue engineering. Certain fundamental issues and design strategies relevant to the material carriers that are being actively pursued to address specific technical objectives are discussed. Recent progress highlights the importance of materials science and engineering in growth factor delivery approaches to regenerative medicine.

  15. Stable carbon and nitrogen isotope trophic enrichment factors for Steller sea lion vibrissae relative to milk and fish/invertebrate diets

    Science.gov (United States)

    Stricker, Craig A.; Christ, Aaron M.; Wunder, Michael B.; Doll, Andrew C.; Farley, Sean D.; Rea, Lorrie D.; Rosen, David A. S.; Scherer, R. D.; Tollit, Dominic J.

    2015-01-01

    Nutritional constraints have been proposed as a contributor to population declines in the endangered Steller sea lion Eumetopias jubatus in some regions of the North Pacific. Isotopic analysis of vibrissae (whiskers) is a potentially useful approach to resolving the nutritional ecology of this species because long-term (up to 8 yr) dietary information is sequentially recorded and metabolically inert once formed. Additionally, vibrissae are grown in utero, potentially offering indirect inference on maternal diet. However, diet reconstruction using isotopic techniques requires a priori knowledge of trophic enrichment factors (TEFs), which can vary relative to diet quality and among animal species. In this study, we provide new TEF estimates for (1) maternal relative to pup vibrissae during both gestation and nursing and (2) adult vibrissae relative to a complex diet. Further, we refine vibrissa-milk TEFs based on an additional 76 animals with an age distribution ranging from 1 to 20 mo. Mother-pup vibrissae TEF values during gestation and nursing were near zero for δ13C and averaged 0.8 and 1.6‰, respectively, for δ15N. In contrast, vibrissa-fish/invertebrate TEFs averaged 3.3 (± 0.3 SD) and 3.7‰ (±0.3) for lipid-free δ13C and δ15N, respectively. Average lipid-free δ13C and δ15N vibrissa-milk TEFs were 2.5 (±0.9) and 1.8‰ (±0.8), respectively, and did not differ among metapopulations. Empirically determined TEFs are critical for accurate retrospective diet modeling, particularly for evaluating the hypothesis of nutritional deficiency contributing to the lack of Steller sea lion population recovery in some regions of Alaska.

  16. Near room temperature approaches for the preparation of air-stable and crystalline CH{sub 3}NH{sub 3}PbI{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Gujarathi, Yogini D.; Haram, Santosh K., E-mail: haram@chem.unipune.ac.in

    2016-04-15

    This work demonstrates an exotic role of CH{sub 2}Cl{sub 2} in a formation of stable phase of highly crystalline CH{sub 3}NH{sub 3}PbI{sub 3} perovskite, on a bulk scale. In the first method, a partially-reacted product obtained after co-grinding of precursors viz. CH{sub 3}NH{sub 3}I and PbI{sub 2}was sonicated in CH{sub 2}Cl{sub 2} to form pure phase of CH{sub 3}NH{sub 3}PbI{sub 3}. In second method, the precursors in γ-Butyrolactone were treated with CH{sub 2}Cl{sub 2} to form crystalline and phase-pure CH{sub 3}NH{sub 3}PbI{sub 3}. X-ray Diffraction analysis confirmed the formation of stable and highly crystalline tetragonal phase of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite having space group I4cm. Well-defined rhombo-hexagonal dodecahedron crystals were seen in SEM and TEM images. Exceptional air stability of CH{sub 3}NH{sub 3}PbI{sub 3} so forms are attributed to adsorption of CH{sub 2}Cl{sub 2}. Optical band gaps obtained from the diffused reflectance spectra (Kubelka–Munk analysis), matched very well with the one estimated from Cyclic Voltammetry (CV). Valence band and conduction band edge positions estimated from the CV analysis are in good agreement with the one reported from UV photoelectron spectroscopy. Both the samples gave steady state fluorescence at ca. 750 nm with quantum yields in the range 15–35.5%. - Highlights: • A role of CH{sub 2}Cl{sub 2} is brought out in formation of stable CH{sub 3}NH{sub 3}PbI{sub 3} perovskite. • Cyclic voltammetry has been used to estimate the band edge positions. • Excellent fluorescence quantum yield, underlines the minimal structural defects.

  17. Bayesian Exploratory Factor Analysis

    DEFF Research Database (Denmark)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corr......This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor......, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates...

  18. Bayesian Exploratory Factor Analysis

    Science.gov (United States)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.; Piatek, Rémi

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates from a high dimensional set of psychological measurements. PMID:25431517

  19. Assessing food web dynamics and relative importance of organic matter sources for fish species in two Portuguese estuaries: a stable isotope approach.

    Science.gov (United States)

    França, Susana; Vasconcelos, Rita P; Tanner, Susanne; Máguas, Cristina; Costa, Maria José; Cabral, Henrique N

    2011-10-01

    Stable carbon and nitrogen isotopes (δ¹³C, δ¹⁵N) were used to analyse food web dynamics of two of the main estuaries of the Portuguese coast: Tejo and Mira. The ultimate sources of organic matter supporting production of some of the most abundant and commercially important fish species were determined; and seasonal, inter- and intra- estuarine differences in the trophic relations among producers and consumers were identified. Stable isotope analysis was performed in different producers, primary consumers (main prey items for fish) and fish species (Solea solea, Solea senegalensis, Pomatoschistus microps, Dicentrarchus labrax, Liza ramada, Diplodus vulgaris and Atherina presbyter) of two areas in each estuary, in July and October 2009. Model calculations showed that the main prey for the fish species in the Tejo estuary used mostly salt marsh-derived organic matter as nutritional sources, with no marked differences between the sampled months. Trophic levels of fish species from the same estuary differed at multiple scales: inter-species, seasonally and spatially (both between and within estuaries). Significant differences in isotopic composition of fish species were more pronounced spatially (between the two sampled areas in the estuary) than seasonally (between sampled months). Trophic relationships in both estuaries demonstrated that organic matter is transferred to higher trophic positions mainly through benthic pathways. This shows the flexibility of these species to share resources and to exploit temporary peaks in prey populations. The present results showed that extensive disturbance in intertidal habitats from both estuaries may potentially change the balance of organic matter in the base of these complex food webs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. A new approach to establish both stable and metastable phase equilibria for fcc ordered/disordered phase transition: application to the Al–Ni and Ni–Si systems

    International Nuclear Information System (INIS)

    Yuan Xiaoming; Zhang Lijun; Du Yong; Xiong Wei; Tang Ying; Wang Aijun; Liu Shuhong

    2012-01-01

    Both two-sublattice (2SL) and four-sublattice (4SL) models in the framework of the compound energy formalism can be used to describe the fcc ordered/disordered transitions. When transferring the parameters of 2SL disregarding the metastable ordered states into those of 4SL, inconsistence in either stable or metastable phase diagrams could appear, as detected in both Al–Ni and Ni–Si systems. To avoid such a kind of drawback, this behavior was analyzed and investigated in the Ni–Si and Al–Ni systems with the aid of first–principle calculations. Furthermore, a new approach considering both the stable and metastable fcc ordered phase equilibria deduced from the first–principles calculations was proposed to perform a reliable thermodynamic modeling for the fcc ordered/disordered transition. The Ni–Si system was then thermodynamically assessed using the presently proposed approach. The good agreement between the calculation and experiments demonstrates the reliability of the proposed approach. It is expected that the approach is valid for other systems showing complex ordered/disordered transitions. - Highlights: ► We discuss the drawbacks of order/disorder modeling in the Ni–Si and Al–Ni systems. ► We perform ab initio calculation of thermodynamic properties in the Ni–Si system. ► A CALPHAD–type approach is proposed to model the fcc ordered/disordered transition. ► The Ni–Si system was thermodynamically assessed using the new approach.

  1. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  2. An Augmented Incomplete Factorization Approach for Computing the Schur Complement in Stochastic Optimization

    KAUST Repository

    Petra, Cosmin G.

    2014-01-01

    We present a scalable approach and implementation for solving stochastic optimization problems on high-performance computers. In this work we revisit the sparse linear algebra computations of the parallel solver PIPS with the goal of improving the shared-memory performance and decreasing the time to solution. These computations consist of solving sparse linear systems with multiple sparse right-hand sides and are needed in our Schur-complement decomposition approach to compute the contribution of each scenario to the Schur matrix. Our novel approach uses an incomplete augmented factorization implemented within the PARDISO linear solver and an outer BiCGStab iteration to efficiently absorb pivot perturbations occurring during factorization. This approach is capable of both efficiently using the cores inside a computational node and exploiting sparsity of the right-hand sides. We report on the performance of the approach on highperformance computers when solving stochastic unit commitment problems of unprecedented size (billions of variables and constraints) that arise in the optimization and control of electrical power grids. Our numerical experiments suggest that supercomputers can be efficiently used to solve power grid stochastic optimization problems with thousands of scenarios under the strict "real-time" requirements of power grid operators. To our knowledge, this has not been possible prior to the present work. © 2014 Society for Industrial and Applied Mathematics.

  3. Tracing and quantifying lake water and groundwater fluxes in the area under mining dewatering pressure using coupled O and H stable isotope approach.

    Science.gov (United States)

    Lewicka-Szczebak, Dominika; Jędrysek, Mariusz-Orion

    2013-01-01

    Oxygen and hydrogen stable isotopic compositions of precipitation, lake water and groundwater were used to quantitatively asses the water budget related to water inflow and water loss in natural lakes, and mixing between lake water and aquifer groundwater in a mining area of the Lignite Mine Konin, central Poland. While the isotopic composition of precipitation showed large seasonal variations (δ(2)H from-140 to+13 ‰ and δ(18)O from-19.3 to+7.6 ‰), the lake waters were variously affected by evaporation (δ(2)H from-44 to-21 ‰ and δ(18)O from-5.2 to-1.7 ‰) and the groundwater showed varying contribution from mixing with surface water (δ(2)H from-75 to-39 ‰ and δ(18)O from-10.4 to-4.8 ‰). The lake water budget was estimated using a Craig-Gordon model and isotopic mass balance constraint, which enabled us to identify various water sources and to quantify inflow and outflow for each lake. Moreover, we documented that a variable recharge of lake water into the Tertiary aquifer was dependent on mining drainage intensity. A comparison of coupled δ(2)H-δ(18)O data with hydrogeological results indicated better precision of the δ(2)H-based calculations.

  4. Tracing Carbon Flow Through Food Webs on Isolated Coral Reefs in the Central Pacific Ocean Using a Compound-Specific Stable Isotope Approach

    Science.gov (United States)

    Thorrold, S.; McMahon, K.; Braun, C.; Berumen, M. L.; Houghton, L. A.

    2016-02-01

    Coral reefs support spectacularly productive and diverse communities in tropical and sub-tropical waters throughout the world's oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column or benthic primary production and recycled detrital carbon. We coupled analyses of stable carbon isotopes in essential amino acids with Bayesian mixing models to quantify carbon flow from pelagic primary producers, benthic macroalgae and autotrophic symbionts in corals, along with detrital carbon, to coral reef fishes across several feeding guilds and trophic positions, including apex predators (gray reef and black tip reef sharks), on reefs in the Phoenix Islands Protected Area. Excellent separation in multivariate isotope space among end-members at the base of the food web allowed us to quantify the relative proportion of carbon produced by each of the end-members that is assimilated by focal reef fish species. Low local human impacts on the study reefs provided the opportunity to examine carbon fluxs in fully functioning reef food webs, thereby providing an important baseline for examingn human impacts in food webs on stressed reefs in more populated regions in the tropics. Moreover the study reefs are located along a significant gradient in dissolved N concentrations, allowing us to test if end-member proportions vary as a function of pelagic primary productivity levels. Our work provides insights into the roles that diverse carbon sources may play in the structure, function and resilience of coral reef ecosystems.

  5. Factors Influencing Seasonal Influenza Vaccination Uptake in Emergency Medical Services Workers: A Concept Mapping Approach.

    Science.gov (United States)

    Subramaniam, Dipti P; Baker, Elizabeth A; Zelicoff, Alan P; Elliott, Michael B

    2016-08-01

    Seasonal influenza has serious impacts on morbidity and mortality and has a significant economic toll through lost workforce time and strains on the health system. Health workers, particularly emergency medical services (EMS) workers have the potential to transmit influenza to those in their care, yet little is known of the factors that influence EMS workers' decisions regarding seasonal influenza vaccination (SIV) uptake, a key factor in reducing potential for transmitting disease. This study utilizes a modified Theory of Planned Behavior (TPB) model as a guiding framework to explore the factors that influence SIV uptake in EMS workers. Concept mapping, which consists of six-stages (preparation, generation, structuring, representation, interpretation, and utilization) that use quantitative and qualitative approaches, was used to identify participants' perspectives towards SIV. This study identified nine EMS-conceptualized factors that influence EMS workers' vaccination intent and behavior. The EMS-conceptualized factors align with the modified TPB model and suggest the need to consider community-wide approaches that were not initially conceptualized in the model. Additionally, the expansion of non-pharmaceutical measures went above and beyond original conceptualization. Overall, this study demonstrates the need to develop customized interventions such as messages highlighting the importance of EMS workers receiving SIV as the optimum solution. EMS workers who do not intend to receive the SIV should be provided with accurate information on the SIV to dispel misconceptions. Finally, EMS workers should also receive interventions which promote voluntary vaccination, encouraging them to be proactive in the health decisions they make for themselves.

  6. Human Factors and Systems Engineering Approach to Patient Safety for Radiotherapy

    International Nuclear Information System (INIS)

    Rivera, A. Joy; Karsh, Ben-Tzion

    2008-01-01

    The traditional approach to solving patient safety problems in healthcare is to blame the last person to touch the patient. But since the publication of To Err is Human, the call has been instead to use human factors and systems engineering methods and principles to solve patient safety problems. However, an understanding of the human factors and systems engineering is lacking, and confusion remains about what it means to apply their principles. This paper provides a primer on them and their applications to patient safety

  7. Combination of Evidence with Different Weighting Factors: A Novel Probabilistic-Based Dissimilarity Measure Approach

    Directory of Open Access Journals (Sweden)

    Mengmeng Ma

    2015-01-01

    Full Text Available To solve the invalidation problem of Dempster-Shafer theory of evidence (DS with high conflict in multisensor data fusion, this paper presents a novel combination approach of conflict evidence with different weighting factors using a new probabilistic dissimilarity measure. Firstly, an improved probabilistic transformation function is proposed to map basic belief assignments (BBAs to probabilities. Then, a new dissimilarity measure integrating fuzzy nearness and introduced correlation coefficient is proposed to characterize not only the difference between basic belief functions (BBAs but also the divergence degree of the hypothesis that two BBAs support. Finally, the weighting factors used to reassign conflicts on BBAs are developed and Dempster’s rule is chosen to combine the discounted sources. Simple numerical examples are employed to demonstrate the merit of the proposed method. Through analysis and comparison of the results, the new combination approach can effectively solve the problem of conflict management with better convergence performance and robustness.

  8. Stable Isotope Ratios as Biomarkers of Diet for Health Research.

    Science.gov (United States)

    O'Brien, Diane M

    2015-01-01

    Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in self-reported methods of diet assessment. Consequently, there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short- and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general US population. Approaches to improve specificity for specific foods are needed; for example, by modeling intake using multiple stable isotope ratios or by isolating and measuring specific molecules linked to foods of interest.

  9. Stable Isotope Ratios as Biomarkers of Diet for Health Research

    Science.gov (United States)

    O’Brien, Diane M.

    2016-01-01

    Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in self-reported methods of diet assessment. Consequently there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general United States population. Approaches to improve specificity for specific foods are needed, for example, by modeling intake using multiple stable isotope ratios, or by isolating and measuring specific molecules linked to foods of interest. PMID:26048703

  10. Heavy-quark hadroproduction in kT-factorization approach with unintegrated gluon distributions

    International Nuclear Information System (INIS)

    Shabelski, Yu.M.; Shuvaev, A.G.

    2006-01-01

    The processes of heavy-quark production using the unintegrated gluon distributions are considered. The numerical predictions for high-energy nucleon-nucleon and photon-nucleon collisions of the k T -factorization approach (semihard theory) are compared with the experimental data from Tevatron collider and HERA. The total production cross sections and p T distributions are considered and they are in reasonable agreement with the data for reasonable values of QCD scale [ru

  11. The Directional Identification Problem in Bayesian Factor Analysis: An Ex-Post Approach

    OpenAIRE

    Pape, Markus; Aßmann, Christian; Boysen-Hogrefe, Jens

    2013-01-01

    Due to their well-known indeterminacies, factor models require identifying assumptions to guarantee unique parameter estimates. For Bayesian estimation, these identifying assumptions are usually implemented by imposing constraints on certain model parameters. This strategy, however, may result in posterior distributions with shapes that depend on the ordering of cross-sections in the data set. We propose an alternative approach, which relies on a sampler without the usual identifying constrai...

  12. Prognostic factors in invasive bladder carcinoma treated by combined modality protocol (organ-sparing approach)

    International Nuclear Information System (INIS)

    Matos, Tadeja; Cufer, Tanja; Cervek, Jozica; Borstnar, Simona; Kragelj, Borut; Zumer-Pregelj, Mirjana

    2000-01-01

    Purpose: The results of bladder sparing approach for the treatment of muscle-invasive bladder cancer, using a combination of transurethral resection (TUR), chemotherapy, and radiotherapy, are encouraging. The survival of patients treated by this method is similar to the survival of patients treated by radical cystectomy. The aim of our study was to find out which pretreatment characteristics influence the survival of patients treated by organ sparing approach that would enable us to identify the patients most suitable for this type of treatment. Methods and Materials: The prognostic value of different factors, such as age, gender, performance status, hemoglobin level, clinical stage, histologic grade, presence of obstructive uropathy, and completeness of TUR, has been studied in 105 patients with invasive bladder cancer, who received a bladder sparing treatment in the period from 1988 to 1995. They were treated with a combination of TUR, followed by 2-4 cycles of methotrexate, cisplatinum, and vinblastine polychemotherapy. In complete responders the treatment was completed by radiotherapy (50 Gy to the bladder and 40 Gy to the regional lymph nodes), whereas nonresponders underwent cystectomy whenever feasible. Results: Our study has confirmed an independent prognostic value of performance status, histologic grade, and obstructive uropathy, for the disease-specific survival (DSS) of bladder cancer patients treated by a conservative approach. We believe that performance status best reflects the extent of disease and exerts significant influence on the extent and course of treatment, while obstructive uropathy is a good indicator of local spread of the disease, better than clinical T-stage. Our finding that histologic grade is one of the strongest prognostic factors shows that tumor biology also is a very important prognostic factor in patients treated by conservative approach. Conclusion: Patients with muscle-invasive bladder cancer who are most likely to benefit

  13. Risk factors for overweight/obesity in preschool children: an ecological approach.

    Science.gov (United States)

    Dev, Dipti A; McBride, Brent A; Fiese, Barbara H; Jones, Blake L; Cho, Hyunkeun

    2013-10-01

    Identification of risk factors is critical to preventing the childhood obesity epidemic. Risk factors that contribute to obesity are multifactorial. However, limited research has focused on identifying obesity risk factors using an ecological approach. Baseline self-report survey data from the STRONG Kids program were used. The sample consisted of 329 parent-child dyads recruited from childcare programs in east-central Illinois. Child height and weight were measured and converted to age- and sex-specific z-scores using standard growth charts. An ecological model provided the theoretical framework for the selection of 22 previously reported childhood obesity risk factors. Multiple logistic regression analyses were used to identify risk factors. Of 22 potential risk factors, three were found to be significantly associated with child overweight/obesity. These included child nighttime sleep duration (χ(2)=8.56; p=0.003), parent BMI (χ(2)=5.62; p=0.01), and parental restrictive feeding for weight control (χ(2)=4.77; p=0.02). Children who slept for 8 hours and less were 2.2 times more likely to be overweight/obese [95% confidence interval (CI): 1.3-3.7), whereas children with an overweight/obese parent were 1.9 times more likely to be overweight/obese (95% CI: 1.12-3.2). Finally, children whose parents used restrictive feeding practices were 1.75 times more likely to be overweight/obese (95% CI: 1.06-2.9). Using an ecological approach, we conclude that childhood obesity prevention efforts may benefit from targeting the key risk factors of child sleep duration, parent BMI, and parental restrictive feeding practices as focus areas for obesity prevention.

  14. Green technological approach to synthesis hydrophobic stable crystalline calcite particles with one-pot synthesis for oil-water separation during oil spill cleanup.

    Science.gov (United States)

    Wu, Min-Nan; Maity, Jyoti Prakash; Bundschuh, Jochen; Li, Che-Feng; Lee, Chin-Rong; Hsu, Chun-Mei; Lee, Wen-Chien; Huang, Chung-Ho; Chen, Chien-Yen

    2017-10-15

    The process of separating oil and water from oil/water mixtures is an attractive strategy to answer the menace caused by industrial oil spills and oily wastewater. In addition, water coproduced during hydrocarbon exploitation, which can be an economic burden and risk for freshwater resources, can become an important freshwater source after suitable water-oil separation. For oil-water separation purposes, considerable attention has been paid to the preparation of hydrophobic-oleophilic materials with modified surface roughness. However, due to issues of thermodynamic instability, costly and complex methods as well as lack of ecofriendly compounds, most of hydrophobic surface modified particles are of limited practical application. The study presents a facile procedure, to synthesize crystalline particles of calcite, which is the most stable polymorph of CaCO 3 from industrial CaCO 3 using oleic acid as an additive in a one-pot synthesis method. The XRD results show that the synthesized particles were a well-crystallized form of calcite. The FTIR results reflect the appearance of the alkyl groups from the oleic acid in synthesized particles which promotes the production of calcite with 'rice shape' (1.64 μm) (aggregated by spherical nanoparticle of 19.56 nm) morphology with concomitant changes in its surface wettability from hydrophilic to hydrophobic. The synthesized particles exhibited near to super hydrophobicity with ∼99% active ratio and a contact angle of 143.8°. The synthesized hydrophobic calcite particles had an oleophilic nature where waste diesel oil adsorption capacity of synthesized calcium carbonate (HCF) showed a very high (>99%) and fast (7 s) oil removal from oil-water mixture. The functional group of long alkyl chain including of CO bounds may play critical roles for adsorption of diesel oils. Moreover, the thermodynamically stable crystalline polymorph calcite (compared to vaterite) exhibited excellent recyclability. The isothermal study

  15. Recent advances in the management of chronic stable angina I: approach to the patient, diagnosis, pathophysiology, risk stratification, and gender disparities.

    Science.gov (United States)

    Kones, Richard

    2010-08-09

    The potential importance of both prevention and personal responsibility in controlling heart disease, the leading cause of death in the USA and elsewhere, has attracted renewed attention. Coronary artery disease is preventable, using relatively simple and inexpensive lifestyle changes. The inexorable rise in the prevalence of obesity, diabetes, dyslipidemia, and hypertension, often in the risk cluster known as the metabolic syndrome, drives the ever-increasing incidence of heart disease. Population-wide improvements in personal health habits appear to be a fundamental, evidence based public health measure, yet numerous barriers prevent implementation. A common symptom in patients with coronary artery disease, classical angina refers to the typical chest pressure or discomfort that results when myocardial oxygen demand rises and coronary blood flow is reduced by fixed, atherosclerotic, obstructive lesions. Different forms of angina and diagnosis, with a short description of the significance of pain and silent ischemia, are discussed in this review. The well accepted concept of myocardial oxygen imbalance in the genesis of angina is presented with new data about clinical pathology of stable angina and acute coronary syndromes. The roles of stress electrocardiography and stress myocardial perfusion scintigraphic imaging are reviewed, along with the information these tests provide about risk and prognosis. Finally, the current status of gender disparities in heart disease is summarized. Enhanced risk stratification and identification of patients in whom procedures will meaningfully change management is an ongoing quest. Current guidelines emphasize efficient triage of patients with suspected coronary artery disease. Many experts believe the predictive value of current decision protocols for coronary artery disease still needs improvement in order to optimize outcomes, yet avoid unnecessary coronary angiograms and radiation exposure. Coronary angiography remains the

  16. Recent advances in the management of chronic stable angina I: Approach to the patient, diagnosis, pathophysiology, risk stratification, and gender disparities

    Science.gov (United States)

    Kones, Richard

    2010-01-01

    The potential importance of both prevention and personal responsibility in controlling heart disease, the leading cause of death in the USA and elsewhere, has attracted renewed attention. Coronary artery disease is preventable, using relatively simple and inexpensive lifestyle changes. The inexorable rise in the prevalence of obesity, diabetes, dyslipidemia, and hypertension, often in the risk cluster known as the metabolic syndrome, drives the ever-increasing incidence of heart disease. Population-wide improvements in personal health habits appear to be a fundamental, evidence based public health measure, yet numerous barriers prevent implementation. A common symptom in patients with coronary artery disease, classical angina refers to the typical chest pressure or discomfort that results when myocardial oxygen demand rises and coronary blood flow is reduced by fixed, atherosclerotic, obstructive lesions. Different forms of angina and diagnosis, with a short description of the significance of pain and silent ischemia, are discussed in this review. The well accepted concept of myocardial oxygen imbalance in the genesis of angina is presented with new data about clinical pathology of stable angina and acute coronary syndromes. The roles of stress electrocardiography and stress myocardial perfusion scintigraphic imaging are reviewed, along with the information these tests provide about risk and prognosis. Finally, the current status of gender disparities in heart disease is summarized. Enhanced risk stratification and identification of patients in whom procedures will meaningfully change management is an ongoing quest. Current guidelines emphasize efficient triage of patients with suspected coronary artery disease. Many experts believe the predictive value of current decision protocols for coronary artery disease still needs improvement in order to optimize outcomes, yet avoid unnecessary coronary angiograms and radiation exposure. Coronary angiography remains the

  17. Simplified probabilistic approach to determine safety factors in deterministic flaw acceptance criteria

    International Nuclear Information System (INIS)

    Barthelet, B.; Ardillon, E.

    1997-01-01

    The flaw acceptance rules in nuclear components rely on deterministic criteria supposed to ensure the safe operating of plants. The interest of having a reliable method of evaluating the safety margins and the integrity of components led Electricite de France to launch a study to link safety factors with requested reliability. A simplified analytical probabilistic approach is developed to analyse the failure risk in Fracture Mechanics. Assuming lognormal distributions of the main random variables, it is possible considering a simple Linear Elastic Fracture Mechanics model, to determine the failure probability as a function of mean values and logarithmic standard deviations. The 'design' failure point can be analytically calculated. Partial safety factors on the main variables (stress, crack size, material toughness) are obtained in relation with reliability target values. The approach is generalized to elastic plastic Fracture Mechanics (piping) by fitting J as a power law function of stress, crack size and yield strength. The simplified approach is validated by detailed probabilistic computations with PROBAN computer program. Assuming reasonable coefficients of variations (logarithmic standard deviations), the method helps to calibrate safety factors for different components taking into account reliability target values in normal, emergency and faulted conditions. Statistical data for the mechanical properties of the main basic materials complement the study. The work involves laboratory results and manufacture data. The results of this study are discussed within a working group of the French in service inspection code RSE-M. (authors)

  18. New insights into the Middle Pleistocene paleoecology and paleoenvironment of the Northern Iberian Peninsula (Punta Lucero Quarry site, Biscay): A combined approach using mammalian stable isotope analysis and trophic resource availability modeling

    Science.gov (United States)

    Domingo, Laura; Rodríguez-Gómez, Guillermo; Libano, Iñaki; Gómez-Olivencia, Asier

    2017-08-01

    The northern coastal area of the Iberian Peninsula shows an excellent archaeo-paleontological record with a unique representation of Pleistocene mammalian fossils. While the Late Pleistocene is better recorded, the Middle Pleistocene record remains more fragmentary. The Punta Lucero site (Biscay) has yielded the most important fossil assemblage of the middle Middle Pleistocene for the northern Iberian Peninsula in both, number of identified specimens and taxonomic diversity. Punta Lucero constitutes a unique opportunity to evaluate Middle Pleistocene mammalian resource and habitat use, and trophic dynamics employing a combined approach: biogeochemical analysis and mathematical modeling. Stable isotope analysis points to resource partitioning between Punta Lucero cervids and bovids. Stable isotope analysis and trophic modeling evidence resource overlap and interspecific competition among predators, especially between the scimitar-toothed cat Homotherium latidens and the European jaguar Panthera gombaszoegensis. The trophic resource availability modeling assumes that Canis mosbachensis consumed a 20% of preys of more than 10 kg, mainly as carrion. Thus, while there would be a taxonomic overlap with those preys consumed by the large felids, the different strategy would have facilitated the coexistence of these canids with larger carnivores. Trophic modeling indicates a high competition among the predator guild. The potential presence of hominins in the area would have reached to an unsustainable situation. However, the potential presence of other prey species, such as Equus sp., would have made the ecosystem more sustainable. The methodology followed in this study highlights the potential of multidisciplinary approaches in the assessment of Pleistocene faunal dynamics.

  19. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  20. Using an interdisciplinary approach to identify factors that affect clinicians' compliance with evidence-based guidelines.

    Science.gov (United States)

    Gurses, Ayse P; Marsteller, Jill A; Ozok, A Ant; Xiao, Yan; Owens, Sharon; Pronovost, Peter J

    2010-08-01

    Our objective was to identify factors that affect clinicians' compliance with the evidence-based guidelines using an interdisciplinary approach and develop a conceptual framework that can provide a comprehensive and practical guide for designing effective interventions. A literature review and a brainstorming session with 11 researchers from a variety of scientific disciplines were used to identify theoretical and conceptual models describing clinicians' guideline compliance. MEDLINE, EMBASE, CINAHL, and the bibliographies of the papers identified were used as data sources for identifying the relevant theoretical and conceptual models. Thirteen different models that originated from various disciplines including medicine, rural sociology, psychology, human factors and systems engineering, organizational management, marketing, and health education were identified. Four main categories of factors that affect compliance emerged from our analysis: clinician characteristics, guideline characteristics, system characteristics, and implementation characteristics. Based on these findings, we developed an interdisciplinary conceptual framework that specifies the expected interrelationships among these four categories of factors and their impact on clinicians' compliance. An interdisciplinary approach is needed to improve clinicians' compliance with evidence-based guidelines. The conceptual framework from this research can provide a comprehensive and systematic guide to identify barriers to guideline compliance and design effective interventions to improve patient safety.

  1. Bridging the Gap between Biologic, Individual, and Macroenvironmental Factors in Cancer: A Multilevel Approach

    Science.gov (United States)

    Lynch, Shannon M.; Rebbeck, Timothy R.

    2013-01-01

    To address the complex nature of cancer occurrence and outcomes, approaches have been developed to simultaneously assess the role of two or more etiological agents within hierarchical levels including the: 1) macro-environment level (e.g., health care policy, neighborhood, or family structure); 2) individual level (e.g., behaviors, carcinogenic exposures, socioeconomic factors and psychological responses); 3) biological level (e.g., cellular biomarkers and inherited susceptibility variants). Prior multilevel approaches tend to focus on social and environmental hypotheses, and are thus limited in their ability to integrate biological factors into a multilevel framework. This limited integration may be related to the limited translation of research findings into the clinic. We propose a “Multi-level Biological And Social Integrative Construct” (MBASIC) to integrate macro-environment and individual factors with biology. The goal of this framework is to help researchers identify relationships among factors that may be involved in the multifactorial, complex nature of cancer etiology, to aid in appropriate study design, to guide the develop statistical or mechanistic models to study these relationships, and to position the results of these studies for improved intervention, translation, and implementation. MBASIC allows researchers from diverse fields to develop hypotheses of interest under a common conceptual framework, to guide transdisciplinary collaborations, and to optimize the value of multilevel studies for clinical and public health activities. PMID:23462925

  2. Analysis of charmless two-body B decays in factorization-assisted topological-amplitude approach

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Si-Hong; Zhang, Qi-An; Lue, Cai-Dian [Institute of High Energy Physics, Beijing (China); University of Chinese Academy of Sciences, School of Physics, Beijing (China); Lyu, Wei-Ran [Renmin University of China, Physics Department, Beijing (China)

    2017-02-15

    We analyze charmless two-body non-leptonic B decays B → PP, PV under the framework of a factorization-assisted topological-amplitude approach, where P(V) denotes a light pseudoscalar (vector) meson. Compared with the conventional flavor diagram approach, we consider the flavor SU(3) breaking effect assisted by a factorization hypothesis for topological diagram amplitudes of different decay modes, factorizing out the corresponding decay constants and form factors. The non-perturbative parameters of topology diagram magnitudes χ and the strong phase φ are universal; they can be extracted by χ{sup 2} fit from current abundant experimental data of charmless B decays. The number of free parameters and the χ{sup 2} per degree of freedom are both reduced compared with previous analyses. With these best fitted parameters, we predict branching fractions and CP asymmetry parameters of nearly 100 B{sub u,d} and B{sub s} decay modes. The long-standing ππ and πK-CP puzzles are solved simultaneously. (orig.)

  3. Assessment of successful smoking cessation by psychological factors using the Bayesian network approach.

    Science.gov (United States)

    Yang, Xiaorong; Li, Suyun; Pan, Lulu; Wang, Qiang; Li, Huijie; Han, Mingkui; Zhang, Nan; Jiang, Fan; Jia, Chongqi

    2016-07-01

    The association between psychological factors and smoking cessation is complicated and inconsistent in published researches, and the joint effect of psychological factors on smoking cessation is unclear. This study explored how psychological factors jointly affect the success of smoking cessation using a Bayesian network approach. A community-based case control study was designed with 642 adult male successful smoking quitters as the cases, and 700 adult male failed smoking quitters as the controls. General self-efficacy (GSE), trait coping style (positive-trait coping style (PTCS) and negative-trait coping style (NTCS)) and self-rating anxiety (SA) were evaluated by GSE Scale, Trait Coping Style Questionnaire and SA Scale, respectively. Bayesian network was applied to evaluate the relationship between psychological factors and successful smoking cessation. The local conditional probability table of smoking cessation indicated that different joint conditions of psychological factors led to different outcomes for smoking cessation. Among smokers with high PTCS, high NTCS and low SA, only 36.40% successfully quitted smoking. However, among smokers with low pack-years of smoking, high GSE, high PTCS and high SA, 63.64% successfully quitted smoking. Our study indicates psychological factors jointly influence smoking cessation outcome. According to different joint situations, different solutions should be developed to control tobacco in practical intervention.

  4. Combined action of ionizing radiation with another factor: common rules and theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Roh, Changhyun, E-mail: jkkim@kaeri.re.kr [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Komarova, Ludmila N.; Petin, Vladislav G., E-mail: vgpetin@yahoo.com [Medical Radiological Research Center, Obninsk (Russian Federation)

    2013-07-01

    Two or more factors can simultaneously make their combined effects on the biological objects. This study has focused on theoretical approach to synergistic interaction due to the combined action of radiation and another factor on cell inactivation. A mathematical model for the synergistic interaction of different environmental agents was suggested for quantitative prediction of irreversibly damaged cells after combined exposures. The model takes into account the synergistic interaction of agents and based on the supposition that additional effective damages responsible for the synergy are irreversible and originated from an interaction of ineffective sub lesions. The experimental results regarding the irreversible component of radiation damage of diploid yeast cells simultaneous exposed to heat with ionizing radiation or UV light are presented. A good agreement of experimental results with model predictions was demonstrated. The importance of the results obtained for the interpretation of the mechanism of synergistic interaction of various environmental factors is discussed. (author)

  5. Recent advances in the management of chronic stable angina I: Approach to the patient, diagnosis, pathophysiology, risk stratification, and gender disparities

    Directory of Open Access Journals (Sweden)

    Richard Kones

    2010-07-01

    Full Text Available Richard KonesThe Cardiometabolic Research Institute, Houston, Texas 77054 USAAbstract: The potential importance of both prevention and personal responsibility in ­controlling heart disease, the leading cause of death in the USA and elsewhere, has attracted renewed ­attention. Coronary artery disease is preventable, using relatively simple and inexpensive lifestyle changes. The inexorable rise in the prevalence of obesity, diabetes, dyslipidemia, and ­hypertension, often in the risk cluster known as the metabolic syndrome, drives the ­ever-increasing incidence of heart disease. Population-wide improvements in personal health habits appear to be a fundamental, evidence based public health measure, yet numerous barriers prevent implementation. A common symptom in patients with coronary artery disease, classical angina refers to the typical chest pressure or discomfort that results when myocardial oxygen demand rises and coronary blood flow is reduced by fixed, atherosclerotic, obstructive lesions. Different forms of angina and diagnosis, with a short description of the significance of pain and silent ischemia, are discussed in this review. The well accepted concept of myocardial oxygen imbalance in the genesis of angina is presented with new data about clinical pathology of stable angina and acute coronary syndromes. The roles of stress electrocardiography and stress myocardial perfusion scintigraphic imaging are reviewed, along with the information these tests provide about risk and prognosis. Finally, the current status of gender disparities in heart disease is summarized. Enhanced risk stratification and identification of patients in whom procedures will meaningfully change management is an ongoing quest. Current guidelines emphasize efficient triage of patients with suspected coronary artery disease. Many experts believe the predictive value of current decision protocols for coronary artery disease still needs improvement in order to

  6. A Parzen window-based approach for the detection of locally enriched transcription factor binding sites.

    Science.gov (United States)

    Vandenbon, Alexis; Kumagai, Yutaro; Teraguchi, Shunsuke; Amada, Karlou Mar; Akira, Shizuo; Standley, Daron M

    2013-01-21

    Identification of cis- and trans-acting factors regulating gene expression remains an important problem in biology. Bioinformatics analyses of regulatory regions are hampered by several difficulties. One is that binding sites for regulatory proteins are often not significantly over-represented in the set of DNA sequences of interest, because of high levels of false positive predictions, and because of positional restrictions on functional binding sites with regard to the transcription start site. We have developed a novel method for the detection of regulatory motifs based on their local over-representation in sets of regulatory regions. The method makes use of a Parzen window-based approach for scoring local enrichment, and during evaluation of significance it takes into account GC content of sequences. We show that the accuracy of our method compares favourably to that of other methods, and that our method is capable of detecting not only generally over-represented regulatory motifs, but also locally over-represented motifs that are often missed by standard motif detection approaches. Using a number of examples we illustrate the validity of our approach and suggest applications, such as the analysis of weaker binding sites. Our approach can be used to suggest testable hypotheses for wet-lab experiments. It has potential for future analyses, such as the prediction of weaker binding sites. An online application of our approach, called LocaMo Finder (Local Motif Finder), is available at http://sysimm.ifrec.osaka-u.ac.jp/tfbs/locamo/.

  7. Precipitation areal-reduction factor estimation using an annual-maxima centered approach

    Science.gov (United States)

    Asquith, W.H.; Famiglietti, J.S.

    2000-01-01

    The adjustment of precipitation depth of a point storm to an effective (mean) depth over a watershed is important for characterizing rainfall-runoff relations and for cost-effective designs of hydraulic structures when design storms are considered. A design storm is the precipitation point depth having a specified duration and frequency (recurrence interval). Effective depths are often computed by multiplying point depths by areal-reduction factors (ARF). ARF range from 0 to 1, vary according to storm characteristics, such as recurrence interval; and are a function of watershed characteristics, such as watershed size, shape, and geographic location. This paper presents a new approach for estimating ARF and includes applications for the 1-day design storm in Austin, Dallas, and Houston, Texas. The approach, termed 'annual-maxima centered,' specifically considers the distribution of concurrent precipitation surrounding an annual-precipitation maxima, which is a feature not seen in other approaches. The approach does not require the prior spatial averaging of precipitation, explicit determination of spatial correlation coefficients, nor explicit definition of a representative area of a particular storm in the analysis. The annual-maxima centered approach was designed to exploit the wide availability of dense precipitation gauge data in many regions of the world. The approach produces ARF that decrease more rapidly than those from TP-29. Furthermore, the ARF from the approach decay rapidly with increasing recurrence interval of the annual-precipitation maxima. (C) 2000 Elsevier Science B.V.The adjustment of precipitation depth of a point storm to an effective (mean) depth over a watershed is important for characterizing rainfall-runoff relations and for cost-effective designs of hydraulic structures when design storms are considered. A design storm is the precipitation point depth having a specified duration and frequency (recurrence interval). Effective depths are

  8. Stable production of human insulin-like growth factor 1 (IGF-1) in the milk of hemi- and homozygous transgenic rabbits over several generations.

    Science.gov (United States)

    Zinovieva, N; Lassnig, C; Schams, D; Besenfelder, U; Wolf, E; Müller, S; Frenyo, L; Seregi, J; Müller, M; Brem, G

    1998-11-01

    One transgenic rabbit line was generated carrying a fusion gene consisting of the cDNA for human IGF-1 fused to a mammary gland specific expression cassette derived from bovine alpha-S1-casein sequences. Transgene expression was shown to be strictly tissue and lactation period specific. The transgenic rabbit line was bred for six generations. All transgenic animals showed stable production of biologically active IGF-1 over the generations and no apparent effect on the physiological or reproductive performance was observed. The absence of adverse effects on homozygous transgenic rabbits suggested the absence of insertional mutagenesis. Eight hemizygous transgenic offspring analysed produced on average 363 +/- 12 micrograms/ml (ranging from 223 +/- 61 to 484 +/- 39 micrograms/ml) mature human IGF-1 in their milk, whereas three homozygous animals produced on average 543 +/- 41 micrograms/ml (ranging from 360 +/- 15 to 678 +/- 80 micrograms/ml). Homozygous hulGF-1 females clearly showed a significantly increased production performance of the recombinant protein.

  9. Factors that influence the approach to leadership: directors of nursing working in rural health services.

    Science.gov (United States)

    Bish, Melanie; Kenny, Amanda; Nay, Rhonda

    2015-04-01

    To identify factors that influence directors of nursing in their approach to leadership when working in rural Victoria, Australia. In rural areas, nurses account for the largest component of the health workforce and must be equipped with leadership knowledge and skills to lead reform at a service level. A qualitative descriptive design was used. In-depth semi-structured interviews were undertaken with directors of nursing from rural Victoria. Data were analysed using thematic analysis and a thematic network was developed. Empowerment emerged as the highest order category in the thematic network. This was derived from three organising themes: influence, capital and contextual understanding and the respective basic themes: formal power, informal power, self-knowledge; information, support, resources; and situational factors, career trajectory, connectedness. Rural nurse leaders contend with several issues that influence their approach to leadership. This study provides a platform for further research to foster nurse leadership in rural healthcare services. Acknowledgement of what influences the rural nurse leaders' approach to leadership may assist in the implementation of initiatives designed to develop leadership in a manner that is contextually sensitive. © 2013 John Wiley & Sons Ltd.

  10. Designing medical technology for resilience: integrating health economics and human factors approaches.

    Science.gov (United States)

    Borsci, Simone; Uchegbu, Ijeoma; Buckle, Peter; Ni, Zhifang; Walne, Simon; Hanna, George B

    2018-01-01

    The slow adoption of innovation into healthcare calls into question the manner of evidence generation for medical technology. This paper identifies potential reasons for this including a lack of attention to human factors, poor evaluation of economic benefits, lack of understanding of the existing healthcare system and a failure to recognise the need to generate resilient products. Areas covered: Recognising a cross-disciplinary need to enhance evidence generation early in a technology's life cycle, the present paper proposes a new approach that integrates human factors and health economic evaluation as part of a wider systems approach to the design of technology. This approach (Human and Economic Resilience Design for Medical Technology or HERD MedTech) supports early stages of product development and is based on the recent experiences of the National Institute for Health Research London Diagnostic Evidence Co-operative in the UK. Expert commentary: HERD MedTech i) proposes a shift from design for usability to design for resilience, ii) aspires to reduce the need for service adaptation to technological constraints iii) ensures value of innovation at the time of product development, and iv) aims to stimulate discussion around the integration of pre- and post-market methods of assessment of medical technology.

  11. Integrating Human Factors Engineering and Information Processing Approaches to Facilitate Evaluations in Criminal Justice Technology Research.

    Science.gov (United States)

    Salvemini, Anthony V; Piza, Eric L; Carter, Jeremy G; Grommon, Eric L; Merritt, Nancy

    2015-06-01

    Evaluations are routinely conducted by government agencies and research organizations to assess the effectiveness of technology in criminal justice. Interdisciplinary research methods are salient to this effort. Technology evaluations are faced with a number of challenges including (1) the need to facilitate effective communication between social science researchers, technology specialists, and practitioners, (2) the need to better understand procedural and contextual aspects of a given technology, and (3) the need to generate findings that can be readily used for decision making and policy recommendations. Process and outcome evaluations of technology can be enhanced by integrating concepts from human factors engineering and information processing. This systemic approach, which focuses on the interaction between humans, technology, and information, enables researchers to better assess how a given technology is used in practice. Examples are drawn from complex technologies currently deployed within the criminal justice system where traditional evaluations have primarily focused on outcome metrics. Although this evidence-based approach has significant value, it is vulnerable to fully account for human and structural complexities that compose technology operations. Guiding principles for technology evaluations are described for identifying and defining key study metrics, facilitating communication within an interdisciplinary research team, and for understanding the interaction between users, technology, and information. The approach posited here can also enable researchers to better assess factors that may facilitate or degrade the operational impact of the technology and answer fundamental questions concerning whether the technology works as intended, at what level, and cost. © The Author(s) 2015.

  12. Factors Influencing Implementation of OHSAS 18001 in Indian Construction Organizations: Interpretive Structural Modeling Approach.

    Science.gov (United States)

    Rajaprasad, Sunku Venkata Siva; Chalapathi, Pasupulati Venkata

    2015-09-01

    Construction activity has made considerable breakthroughs in the past two decades on the back of increases in development activities, government policies, and public demand. At the same time, occupational health and safety issues have become a major concern to construction organizations. The unsatisfactory safety performance of the construction industry has always been highlighted since the safety management system is neglected area and not implemented systematically in Indian construction organizations. Due to a lack of enforcement of the applicable legislation, most of the construction organizations are forced to opt for the implementation of Occupational Health Safety Assessment Series (OHSAS) 18001 to improve safety performance. In order to better understand factors influencing the implementation of OHSAS 18001, an interpretive structural modeling approach has been applied and the factors have been classified using matrice d'impacts croises-multiplication appliqué a un classement (MICMAC) analysis. The study proposes the underlying theoretical framework to identify factors and to help management of Indian construction organizations to understand the interaction among factors influencing in implementation of OHSAS 18001. Safety culture, continual improvement, morale of employees, and safety training have been identified as dependent variables. Safety performance, sustainable construction, and conducive working environment have been identified as linkage variables. Management commitment and safety policy have been identified as the driver variables. Management commitment has the maximum driving power and the most influential factor is safety policy, which states clearly the commitment of top management towards occupational safety and health.

  13. The Analysis of Theoretical Approaches to Identification of Factors of Regional Economic Growth

    Directory of Open Access Journals (Sweden)

    Kosyrieva Olena V.

    2016-05-01

    Full Text Available The article is devoted to the investigation of current approaches to identification of factors of economic growth in the regions. The theory of new economic geography based on works and studies of P. Krugman has been considered. There highlighted the key issues of regional economic growth requiring an in-depth studying and consideration in the elaboration of strategies for sustainable development of the regions. The views of leading domestic and foreign scholars as well as the OECD experts, the World Bank, the National Statistics Service of the United Kingdom and others on the main drivers of economic growth have been analyzed. On the basis of the study the factors of regional economic growth most commonly encountered in theory and practice have been generalized. It is proved that scientists and analysts most often classify as the factors of regional economic growth the following ones: those characterizing human potential, scientific-technical and innovative activity, management and institutional capacity. The factors less frequently correlated by specialists and scientists with the regional economic growth include: those characterizing the environment, business and sociopolitical factors, which is associated with difficulty of their quantification, but in any case does not diminish their importance.

  14. Charmless B_{(s)}→ VV decays in factorization-assisted topological-amplitude approach

    Science.gov (United States)

    Wang, Chao; Zhang, Qi-An; Li, Ying; Lü, Cai-Dian

    2017-05-01

    Within the factorization-assisted topological-amplitude approach, we studied the 33 charmless B_{(s)} → VV decays, where V stands for a light vector meson. According to the flavor flows, the amplitude of each process can be decomposed into eight different topologies. In contrast to the conventional flavor diagrammatic approach, we further factorize each topological amplitude into decay constant, form factors and unknown universal parameters. By χ ^2 fitting 46 experimental observables, we extracted 10 theoretical parameters with χ ^2 per degree of freedom around 2. Using the fitted parameters, we calculated the branching fractions, polarization fractions, CP asymmetries and relative phases between polarization amplitudes of each decay mode. The decay channels dominated by tree diagram have large branching fractions and large longitudinal polarization fraction. The branching fractions and longitudinal polarization fractions of color-suppressed decays become smaller. Current experimental data of large transverse polarization fractions in the penguin dominant decay channels can be explained by only one transverse amplitude of penguin annihilation diagram. Our predictions of the not yet measured channels can be tested in the ongoing LHCb experiment and the Belle-II experiment in the future.

  15. Safety, reliability, risk management and human factors: an integrated engineering approach applied to nuclear facilities

    International Nuclear Information System (INIS)

    Vasconcelos, Vanderley de; Silva, Eliane Magalhaes Pereira da; Costa, Antonio Carlos Lopes da; Reis, Sergio Carneiro dos

    2009-01-01

    Nuclear energy has an important engineering legacy to share with the conventional industry. Much of the development of the tools related to safety, reliability, risk management, and human factors are associated with nuclear plant processes, mainly because the public concern about nuclear power generation. Despite the close association between these subjects, there are some important different approaches. The reliability engineering approach uses several techniques to minimize the component failures that cause the failure of the complex systems. These techniques include, for instance, redundancy, diversity, standby sparing, safety factors, and reliability centered maintenance. On the other hand system safety is primarily concerned with hazard management, that is, the identification, evaluation and control of hazards. Rather than just look at failure rates or engineering strengths, system safety would examine the interactions among system components. The events that cause accidents may be complex combinations of component failures, faulty maintenance, design errors, human actions, or actuation of instrumentation and control. Then, system safety deals with a broader spectrum of risk management, including: ergonomics, legal requirements, quality control, public acceptance, political considerations, and many other non-technical influences. Taking care of these subjects individually can compromise the completeness of the analysis and the measures associated with both risk reduction, and safety and reliability increasing. Analyzing together the engineering systems and controls of a nuclear facility, their management systems and operational procedures, and the human factors engineering, many benefits can be realized. This paper proposes an integration of these issues based on the application of systems theory. (author)

  16. An information-based rough set approach to critical engineering factor identification

    Directory of Open Access Journals (Sweden)

    Jing Ji

    2008-09-01

    Full Text Available In order to analyze the main critical engineering factors, an information-based rough set approach that considers conditional information entropy as a measurement of information has been developed. An algorithm for continuous attribute discretization based on conditional information entropy and an algorithm for rule extraction considering the supports of rules are proposed. The initial decision system is established by collecting enough monitoring data. Then, the continuous attributes are discretized, and the condition attributes are reduced. Finally, the rules that indicate the action law of the main factors are extracted and the results are explained. By applying this approach to a crack in an arch gravity dam, it can be concluded that the water level and the temperature are the main factors affecting the crack opening, and there is a negative correlation between the crack opening and the temperature. This conclusion corresponds with the observation that cracks in most concrete dams are influenced mainly by water level and temperature, and the influence of temperature is more evident.

  17. Safety, reliability, risk management and human factors: an integrated engineering approach applied to nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Vanderley de; Silva, Eliane Magalhaes Pereira da; Costa, Antonio Carlos Lopes da; Reis, Sergio Carneiro dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: vasconv@cdtn.br, e-mail: silvaem@cdtn.br, e-mail: aclc@cdtn.br, e-mail: reissc@cdtn.br

    2009-07-01

    Nuclear energy has an important engineering legacy to share with the conventional industry. Much of the development of the tools related to safety, reliability, risk management, and human factors are associated with nuclear plant processes, mainly because the public concern about nuclear power generation. Despite the close association between these subjects, there are some important different approaches. The reliability engineering approach uses several techniques to minimize the component failures that cause the failure of the complex systems. These techniques include, for instance, redundancy, diversity, standby sparing, safety factors, and reliability centered maintenance. On the other hand system safety is primarily concerned with hazard management, that is, the identification, evaluation and control of hazards. Rather than just look at failure rates or engineering strengths, system safety would examine the interactions among system components. The events that cause accidents may be complex combinations of component failures, faulty maintenance, design errors, human actions, or actuation of instrumentation and control. Then, system safety deals with a broader spectrum of risk management, including: ergonomics, legal requirements, quality control, public acceptance, political considerations, and many other non-technical influences. Taking care of these subjects individually can compromise the completeness of the analysis and the measures associated with both risk reduction, and safety and reliability increasing. Analyzing together the engineering systems and controls of a nuclear facility, their management systems and operational procedures, and the human factors engineering, many benefits can be realized. This paper proposes an integration of these issues based on the application of systems theory. (author)

  18. A fuel-based approach for emission factor development for highway paving construction equipment in China.

    Science.gov (United States)

    Li, Zhen; Zhang, Kaishan; Pang, Kaili; Di, Baofeng

    2016-12-01

    The objective of this paper is to develop and demonstrate a fuel-based approach for emissions factor estimation for highway paving construction equipment in China for better accuracy. A highway construction site in Chengdu was selected for this study with NO emissions being characterized and demonstrated. Four commonly used paving equipment, i.e., three rollers and one paver were selected in this study. A portable emission measurement system (PEMS) was developed and used for emission measurements of selected equipment during real-world highway construction duties. Three duty modes were defined to characterize the NO emissions, i.e., idling, moving, and working. In order to develop a representative emission factor for these highway construction equipment, composite emission factors were estimated using modal emission rates and the corresponding modal durations in the process of typical construction duties. Depending on duty mode and equipment type, NO emission rate ranged from 2.6-63.7mg/s and 6.0-55.6g/kg-fuel with the fuel consumption ranging from 0.31-4.52 g/s correspondingly. The NO composite emission factor was estimated to be 9-41mg/s with the single-drum roller being the highest and double-drum roller being the lowest and 6-30g/kg-fuel with the pneumatic tire roller being the highest while the double-drum roller being the lowest. For the paver, both time-based and fuel consumption-based NO composite emission rates are higher than all of the rollers with 56mg/s and 30g/kg-fuel, respectively. In terms of time-based quantity, the working mode contributes more than the other modes with idling being the least for both emissions and fuel consumption. In contrast, the fuel-based emission rate appears to have less variability in emissions. Thus, in order to estimate emission factors for emission inventory development, the fuel-based emission factor may be selected for better accuracy. The fuel-based composite emissions factors will be less variable and more accurate

  19. Stable interaction between the human proliferating cell nuclear antigen loader complex Ctf18-replication factor C (RFC) and DNA polymerase {epsilon} is mediated by the cohesion-specific subunits, Ctf18, Dcc1, and Ctf8.

    Science.gov (United States)

    Murakami, Takeshi; Takano, Ryuji; Takeo, Satoshi; Taniguchi, Rina; Ogawa, Kaori; Ohashi, Eiji; Tsurimoto, Toshiki

    2010-11-05

    One of the proliferating cell nuclear antigen loader complexes, Ctf18-replication factor C (RFC), is involved in sister chromatid cohesion. To examine its relationship with factors involved in DNA replication, we performed a proteomics analysis of Ctf18-interacting proteins. We found that Ctf18 interacts with a replicative DNA polymerase, DNA polymerase ε (pol ε). Co-immunoprecipitation with recombinant Ctf18-RFC and pol ε demonstrated that their binding is direct and mediated by two distinct interactions, one weak and one stable. Three subunits that are specifically required for cohesion in yeast, Ctf18, Dcc1, and Ctf8, formed a trimeric complex (18-1-8) and together enabled stable binding with pol ε. The C-terminal 23-amino acid stretch of Ctf18 was necessary for the trimeric association of 18-1-8 and was required for the stable interaction. The weak interaction was observed with alternative loader complexes including Ctf18-RFC(5), which lacks Dcc1 and Ctf8, suggesting that the common loader structures, including the RFC small subunits (RFC2-5), are responsible for the weak interaction. The two interaction modes, mediated through distinguishable structures of Ctf18-RFC, both occurred through the N-terminal half of pol ε, which includes the catalytic domain. The addition of Ctf18-RFC or Ctf18-RFC(5) to the DNA synthesis reaction caused partial inhibition and stimulation, respectively. Thus, Ctf18-RFC has multiple interactions with pol ε that promote polymorphic modulation of DNA synthesis. We propose that their interaction alters the DNA synthesis mode to enable the replication fork to cooperate with the establishment of cohesion.

  20. A unified statistical approach to non-negative matrix factorization and probabilistic latent semantic indexing.

    Science.gov (United States)

    Devarajan, Karthik; Wang, Guoli; Ebrahimi, Nader

    2015-04-01

    Non-negative matrix factorization (NMF) is a powerful machine learning method for decomposing a high-dimensional nonnegative matrix V into the product of two nonnegative matrices, W and H , such that V ∼ W H . It has been shown to have a parts-based, sparse representation of the data. NMF has been successfully applied in a variety of areas such as natural language processing, neuroscience, information retrieval, image processing, speech recognition and computational biology for the analysis and interpretation of large-scale data. There has also been simultaneous development of a related statistical latent class modeling approach, namely, probabilistic latent semantic indexing (PLSI), for analyzing and interpreting co-occurrence count data arising in natural language processing. In this paper, we present a generalized statistical approach to NMF and PLSI based on Renyi's divergence between two non-negative matrices, stemming from the Poisson likelihood. Our approach unifies various competing models and provides a unique theoretical framework for these methods. We propose a unified algorithm for NMF and provide a rigorous proof of monotonicity of multiplicative updates for W and H . In addition, we generalize the relationship between NMF and PLSI within this framework. We demonstrate the applicability and utility of our approach as well as its superior performance relative to existing methods using real-life and simulated document clustering data.

  1. Limitations of the toxic equivalency factor (TEF) approach for risk assessment of halogenated aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Safe, S. [Texas A and M Univ., College Station, TX (United States). Dept. of Veterinary Physiology and Pharmacology

    1995-12-31

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatic hydrocarbons (HAHs) are present as complex mixtures of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) in most environmental matrices. Risk management of these mixtures utilize the toxic equivalency factor (TEF) approach in which the TCDD (dioxin) or toxic equivalents of a mixture is a summation of the congener concentration (Ci) times TEF{sub i} (potency relative to TCDD) where. TEQ{sub mixture} = {Sigma}[Cil] {times} TEF{sub i}. TEQs are determined only for those HAHs which are aryl hydrocarbon (Ah) receptor agonists and this approach assumes that the toxic or biochemical effects of individual compounds in a mixture are additive. Several in vivo and in vitro laboratory and field studies with different HAH mixtures have been utilized to validate the TEF approach. For some responses, the calculated toxicities of PCDD/PCDF and PCB mixtures predict the observed toxic potencies. However, for fetal cleft palate and immunotoxicity in mice, nonadditive (antagonistic) responses are observed using complex PCB mixtures or binary mixtures containing an Ah receptor agonist with 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl (PCB153). The potential interactive effects of PCBs and other dietary Ah receptor antagonist suggest that the TEF approach for risk management of HAHs requires further refinement and should be used selectively.

  2. Human and Organisational Factors in the Licensing Process for New NPPs: The Swiss Approach

    International Nuclear Information System (INIS)

    Ryser, Cornelia

    2011-01-01

    Past and recent construction as well as operating experience has shown the importance of giving due attention to human and organisational factors (HOF) in the design and construction of new NPPs. The present paper primarily deals with the development of regulatory requirements by the Swiss Federal Nuclear Safety Inspectorate (ENSI) concerning HOF engineering aspects, i.e. the design of the work systems of the new NPP (technical systems, work tasks, operating organisation). The requirements concerning quality and project management or the management system in general are not in the main focus of this paper. The approach and requirements presented are not yet fully implemented in the Swiss regulatory framework and are still being worked on. Therefore the issues described in the paper have to be considered as provisional and might still be subject to some change in the next months as the approach and requirements are being further developed and finalised. (author)

  3. Identifying risk factors and protective factors for venous leg ulcer recurrence using a theoretical approach: A longitudinal study.

    Science.gov (United States)

    Finlayson, Kathleen; Wu, Min-Lin; Edwards, Helen E

    2015-06-01

    The high recurrence rate of chronic venous leg ulcers has a significant impact on an individual's quality of life and healthcare costs. This study aimed to identify risk and protective factors for recurrence of venous leg ulcers using a theoretical approach by applying a framework of self and family management of chronic conditions to underpin the study. Secondary analysis of combined data collected from three previous prospective longitudinal studies. The contributing studies' participants were recruited from two metropolitan hospital outpatient wound clinics and three community-based wound clinics. Data were available on a sample of 250 adults, with a leg ulcer of primarily venous aetiology, who were followed after ulcer healing for a median follow-up time of 17 months after healing (range: 3-36 months). Data from the three studies were combined. The original participant data were collected through medical records and self-reported questionnaires upon healing and every 3 months thereafter. A Cox proportion-hazards regression analysis was undertaken to determine the influential factors on leg ulcer recurrence based on the proposed conceptual framework. The median time to recurrence was 42 weeks (95% CI 31.9-52.0), with an incidence of 22% (54 of 250 participants) recurrence within three months of healing, 39% (91 of 235 participants) for those who were followed for six months, 57% (111 of 193) by 12 months, 73% (53 of 72) by two years and 78% (41 of 52) of those who were followed up for three years. A Cox proportional-hazards regression model revealed that the risk factors for recurrence included a history of deep vein thrombosis (HR 1.7, 95% CI 1.07-2.67, p=0.024), history of multiple previous leg ulcers (HR 4.4, 95% CI 1.84-10.5, p=0.001), and longer duration (in weeks) of previous ulcer (HR 1.01, 95% CI 1.003-1.01, pulcer recurrence based on the chronic disease self and family management framework. These results in turn provide essential steps towards

  4. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  5. Stable Boundary Layer Issues

    NARCIS (Netherlands)

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

  6. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    IAS Admin

    After Maynard-Smith and Price [1] mathematically derived why a given behaviour or strategy was adopted by a certain proportion of the population at a given time, it was shown that a strategy which is currently stable in a population need not be stable in evolutionary time (across generations). Additionally it was sug-.

  7. Finite Difference Methods for Option Pricing under Lévy Processes: Wiener-Hopf Factorization Approach

    OpenAIRE

    Kudryavtsev, Oleg

    2013-01-01

    In the paper, we consider the problem of pricing options in wide classes of Lévy processes. We propose a general approach to the numerical methods based on a finite difference approximation for the generalized Black-Scholes equation. The goal of the paper is to incorporate the Wiener-Hopf factorization into finite difference methods for pricing options in Lévy models with jumps. The method is applicable for pricing barrier and American options. The pricing problem is reduced to the sequence o...

  8. Total Factor Productivity Growth, Technical Progress & Efficiency Change in Vietnam Coal Industry - Nonparametric Approach

    Science.gov (United States)

    Phuong, Vu Hung

    2018-03-01

    This research applies Data Envelopment Analysis (DEA) approach to analyze Total Factor Productivity (TFP) and efficiency changes in Vietnam coal mining industry from 2007 to 2013. The TFP of Vietnam coal mining companies decreased due to slow technological progress and unimproved efficiency. The decadence of technical efficiency in many enterprises proved that the coal mining industry has a large potential to increase productivity through technical efficiency improvement. Enhancing human resource training, technology and research & development investment could help the industry to improve efficiency and productivity in Vietnam coal mining industry.

  9. Health care expenditure disparities in the European Union and underlying factors: a distribution dynamics approach.

    Science.gov (United States)

    Villaverde, José; Maza, Adolfo; Hierro, María

    2014-09-01

    This paper examines health care expenditure (HCE) disparities between the European Union countries over the period 1995-2010. By means of using a continuous version of the distribution dynamics approach, the key conclusions are that the reduction in disparities is very weak and, therefore, persistence is the main characteristic of the HCE distribution. In view of these findings, a preliminary attempt is made to add some insights into potentially main factors behind the HCE distribution. The results indicate that whereas per capita income is by far the main determinant, the dependency ratio and female labour participation do not play any role in explaining the HCE distribution; as for the rest of the factors studied (life expectancy, infant mortality, R&D expenditure and public HCE expenditure share), we find that their role falls somewhat in between.

  10. Enterprise Factors Contributing to The Success of Malaysian Biotechnology SMEs: A Grounded Theory Approach

    Directory of Open Access Journals (Sweden)

    Saridan Abu Bakar

    2007-10-01

    Full Text Available While numerous empirical studies have been conducted in Western countries on biotechnology enterprises, little empirical research has been done in Malaysia especially in respect to the factors that contribute to the success of biotechnology small and medium enterprises (SMEs. In view of this, a study was undertaken recently in Malaysia to address this gap in the existing body of biotechnology knowledge. Using a grounded theory approach, this qualitative study managed to develop a conceptual framework that sheds useful information on the enterprise factors that significantly impact the success of Malaysian biotechnology SMEs. Specifically, this study found that organizational structure, innovation activities, linkages with academic research institutions, linkages with other private enterprises, personal linkages with academic researchers, access to financial capital, the procuring of government assistances, vertical integration, enterprise image, GMP compliance and halal certification, strongly influence enterprise success.

  11. Integrated approach to knowledge acquisition and safety management of complex plants with emphasis on human factors

    International Nuclear Information System (INIS)

    Kosmowski, K.T.

    1998-01-01

    In this paper an integrated approach to the knowledge acquisition and safety management of complex industrial plants is proposed and outlined. The plant is considered within a man-technology-environment (MTE) system. The knowledge acquisition is aimed at the consequent reliability evaluation of human factor and probabilistic modeling of the plant. Properly structured initial knowledge is updated in life-time of the plant. The data and knowledge concerning the topology of safety related systems and their functions are created in a graphical CAD system and are object oriented. Safety oriented monitoring of the plant includes abnormal situations due to external and internal disturbances, failures of hard/software components and failures of human factor. The operation and safety related evidence is accumulated in special data bases. Data/knowledge bases are designed in such a way to support effectively the reliability and safety management of the plant. (author)

  12. The Approach to Defining Gravity Factors of Influence on the Foreign Trade Relations of Countries

    Directory of Open Access Journals (Sweden)

    Kalyuzhna Nataliya G.

    2017-03-01

    Full Text Available The aim of the article is to determine the gravity factors of influence on the foreign trade relations of countries on the basis of the results of the comparative analysis of the classical specifications of the gravity model of foreign trade and the domestic experience in gravity modeling. It is substantiated that a gravity model is one of the tools of economic and mathematical modeling, the use of which is characterized by a high level of adequacy and ensures prediction of foreign trade conditions. The main approaches to the definition of explanatory variables in the gravity equation of foreign trade are analyzed, and the author’s approach to the selection of the factors of the gravity model is proposed. As the first explanatory variable in the specification of the gravity model of foreign trade and the characteristics of the importance of economies of foreign trade partners, it is proposed to use the GDP calculated at purchasing power parity with the expected positive and statistically significant coefficient. As the second explanatory variable of the gravity equation of foreign trade, it is proposed to use a complex characteristic of the “trade distance” between countries, which reflects the current conditions of bilateral trade and depends on factors influencing the foreign trade turnover between countries — both directly (static proportionality of transport costs of geographical remoteness, and indirectly (dynamic institutional conditions of bilateral relations. The expediency of using the world average annual price for oil as the quantitative equivalent of the “trading distance” index is substantiated. Prospects for further research in this direction are identifying the form and force of influence of certain basic gravity variables on the foreign trade relations of certain partner countries and determining the appropriateness of including additional factors in the composition of the gravity equation of foreign trade.

  13. Risk Factors Predicting Infectious Lactational Mastitis: Decision Tree Approach versus Logistic Regression Analysis.

    Science.gov (United States)

    Fernández, Leónides; Mediano, Pilar; García, Ricardo; Rodríguez, Juan M; Marín, María

    2016-09-01

    Objectives Lactational mastitis frequently leads to a premature abandonment of breastfeeding; its development has been associated with several risk factors. This study aims to use a decision tree (DT) approach to establish the main risk factors involved in mastitis and to compare its performance for predicting this condition with a stepwise logistic regression (LR) model. Methods Data from 368 cases (breastfeeding women with mastitis) and 148 controls were collected by a questionnaire about risk factors related to medical history of mother and infant, pregnancy, delivery, postpartum, and breastfeeding practices. The performance of the DT and LR analyses was compared using the area under the receiver operating characteristic (ROC) curve. Sensitivity, specificity and accuracy of both models were calculated. Results Cracked nipples, antibiotics and antifungal drugs during breastfeeding, infant age, breast pumps, familial history of mastitis and throat infection were significant risk factors associated with mastitis in both analyses. Bottle-feeding and milk supply were related to mastitis for certain subgroups in the DT model. The areas under the ROC curves were similar for LR and DT models (0.870 and 0.835, respectively). The LR model had better classification accuracy and sensitivity than the DT model, but the last one presented better specificity at the optimal threshold of each curve. Conclusions The DT and LR models constitute useful and complementary analytical tools to assess the risk of lactational infectious mastitis. The DT approach identifies high-risk subpopulations that need specific mastitis prevention programs and, therefore, it could be used to make the most of public health resources.

  14. Human factors evaluation of teletherapy: Identification of problems and alternative approaches. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, K.; Kaye, R.D.; Jones, R. [Hughes Training, Inc., Falls Church, VA (United States); Morisseau, D.S.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1995-07-01

    A series of human factors evaluations was undertaken to better understand the contributing factors to human error in the teletherapy environment. Teletherapy is a multi-disciplinary methodology for treating cancerous tissue through selective exposure to an external beam of ionizing radiation. The principal sources of radiation are a radioactive isotope, typically cobalt60 (Co-60), or a linear accelerator device capable of producing very high energy x-ray and electron beams. A team of human factors specialists, assisted by a panel of radiation oncologists, medical physicists, and radiation technologists, conducted site visits to radiation oncology departments at community hospitals, university centers, and free-standing clinics. A function and task analysis was initially performed to guide subsequent evaluations in the areas of user-system interfaces, procedures, training and qualifications, and organizational policies and practices. The final phase of the project focused on identification of the most significant human factors problems with respect to safe and effective operation of the teletherapy system and an identification and assessment of alternative approaches for resolving the problems. This report presents the findings of this final phase.

  15. Multivariate Normative Comparisons for Neuropsychological Assessment by a Multilevel Factor Structure or Multiple Imputation Approach.

    Science.gov (United States)

    Agelink van Rentergem, Joost A; de Vent, Nathalie R; Schmand, Ben A; Murre, Jaap M J; Huizenga, Hilde M

    2017-05-29

    Neuropsychologists administer neuropsychological tests to decide whether a patient is cognitively impaired. This clinical decision is made by comparing a patient's scores to those of healthy participants in a normative sample. In a multivariate normative comparison, a patient's entire profile of scores is compared to scores in a normative sample. Such a multivariate comparison has been shown to improve clinical decision making. However, it requires a multivariate normative data set, which often is unavailable. To obtain such a multivariate normative data set, the authors propose to aggregate healthy control group data from existing neuropsychological studies. As not all studies administered the same tests, this aggregated database will contain substantial amounts of missing data. The authors therefore propose two solutions: multiple imputation and factor modeling. Simulation studies show that factor modeling is preferred over multiple imputation, provided that the factor model is adequately specified. This factor modeling approach will therefore allow routine use of multivariate normative comparisons, enabling more accurate clinical decision making. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Human factors evaluation of teletherapy: Identification of problems and alternative approaches. Volume 1

    International Nuclear Information System (INIS)

    Henriksen, K.; Kaye, R.D.; Jones, R.; Morisseau, D.S.; Serig, D.I.

    1995-07-01

    A series of human factors evaluations was undertaken to better understand the contributing factors to human error in the teletherapy environment. Teletherapy is a multi-disciplinary methodology for treating cancerous tissue through selective exposure to an external beam of ionizing radiation. The principal sources of radiation are a radioactive isotope, typically cobalt60 (Co-60), or a linear accelerator device capable of producing very high energy x-ray and electron beams. A team of human factors specialists, assisted by a panel of radiation oncologists, medical physicists, and radiation technologists, conducted site visits to radiation oncology departments at community hospitals, university centers, and free-standing clinics. A function and task analysis was initially performed to guide subsequent evaluations in the areas of user-system interfaces, procedures, training and qualifications, and organizational policies and practices. The final phase of the project focused on identification of the most significant human factors problems with respect to safe and effective operation of the teletherapy system and an identification and assessment of alternative approaches for resolving the problems. This report presents the findings of this final phase

  17. Can a Risk Factor Based Approach Safely Reduce Screening for Retinopathy of Prematurity?

    Directory of Open Access Journals (Sweden)

    K. M. Friddle

    2017-01-01

    Full Text Available Objective. Current American retinopathy of prematurity (ROP screening guidelines is imprecise for infants ≥ 30 weeks with birth weights between 1500 and 2000 g. Our objective was to evaluate a risk factor based approach for screening premature infants at low risk for severe ROP. Study Design. We performed a 13-year review from Intermountain Health Care (IHC data. All neonates born at ≤32 weeks were reviewed to determine ROP screening and/or development of severe ROP. Severe ROP was defined by stage ≥ 3 or need for laser therapy. Regression analysis was used to identify significant risk factors for severe ROP. Results. We identified 4607 neonates ≤ 32 weeks gestation. Following exclusion for death, with no retinal exam or incomplete data, 2791 (61% were included in the study. Overall, severe ROP occurred in 260 (9.3%, but only 11/1601 ≥ 29 weeks (0.7%. All infants with severe ROP ≥ 29 weeks had at least 2 identified ROP risk factors. Implementation of this risk based screening strategy to the IHC population over the timeline of this study would have eliminated screening in 21% (343/1601 of the screened population. Conclusions. Limiting ROP screening for infants ≥ 29 and ≤ 32 weeks to only those with clinical risk factors could significantly reduce screening exams while identifying all infants with severe ROP.

  18. Stable-isotope dilution GC-MS approach for nitrite quantification in human whole blood, erythrocytes, and plasma using pentafluorobenzyl bromide derivatization: nitrite distribution in human blood.

    Science.gov (United States)

    Schwarz, Alexandra; Modun, Darko; Heusser, Karsten; Tank, Jens; Gutzki, Frank-Mathias; Mitschke, Anja; Jordan, Jens; Tsikas, Dimitrios

    2011-05-15

    Previously, we reported on the usefulness of pentafluorobenzyl bromide (PFB-Br) for the simultaneous derivatization and quantitative determination of nitrite and nitrate in various biological fluids by GC-MS using their (15)N-labelled analogues as internal standards. As nitrite may be distributed unevenly in plasma and blood cells, its quantification in whole blood rather than in plasma or serum may be the most appropriate approach to determine nitrite concentration in the circulation. So far, GC-MS methods based on PFB-Br derivatization failed to measure nitrite in whole blood and erythrocytes because of rapid nitrite loss by oxidation and other unknown reactions during derivatization. The present article reports optimized and validated procedures for sample preparation and nitrite derivatization which allow for reliable quantification of nitrite in human whole blood and erythrocytes. Essential measures for stabilizing nitrite in these samples include sample cooling (0-4°C), hemoglobin (Hb) removal by precipitation with acetone and short derivatization of the Hb-free supernatant (5 min, 50°C). Potassium ferricyanide (K(3)Fe(CN)(6)) is useful in preventing Hb-caused nitrite loss, however, this chemical is not absolutely required in the present method. Our results show that accurate GC-MS quantification of nitrite as PFB derivative is feasible virtually in every biological matrix with similar accuracy and precision. In EDTA-anticoagulated venous blood of 10 healthy young volunteers, endogenous nitrite concentration was measured to be 486±280 nM in whole blood, 672±496 nM in plasma (C(P)), and 620±350 nM in erythrocytes (C(E)). The C(E)-to-C(P) ratio was 0.993±0.188 indicating almost even distribution of endogenous nitrite between plasma and erythrocytes. By contrast, the major fraction of nitrite added to whole blood remained in plasma. The present GC-MS method is useful to investigate distribution and metabolism of endogenous and exogenous nitrite in blood

  19. Trends in Risk Factors and Treatments in Patients With Stable Ischemic Heart Disease Seen at Cardiology Clinics Between 2006 and 2014.

    Science.gov (United States)

    Cordero, Alberto; Galve, Enrique; Bertomeu-Martínez, Vicente; Bueno, Héctor; Fácila, Lorenzo; Alegría, Eduardo; Cequier, Ángel; Ruiz, Emilio; González-Juanatey, José Ramón

    2016-04-01

    Chronic ischemic heart disease is the most prevalent of all cardiovascular diseases. Patients are at high risk of complications. In recent decades, changes may have occurred in the clinical characteristics of the disease, its treatment and control of risk factors. A direct comparison of 2 national registries of patients with chronic ischemic heart disease carried out in 2006 (n=1583) and 2014 (n=1110). We observed statistically significant differences between the 2 registries, with a higher percentage of men and smokers in the 2014 registry, but a lower prevalence of diabetes mellitus and hypertension. Heart failure and stroke were more prevalent in the 2006 registry. Patients in the 2014 registry had better results for lipid profile, blood glucose, creatinine, and glomerular filtration rate. We observed higher use of recommended drugs for secondary prevention and an increased percentage of patients receiving optimal medical therapy, from 32.5% to 49.5% (P<.01). Use of high-intensity statin doses also increased from 10.5% to 42.8% (P<.01). We found better control of some risk factors (improved dyslipidemia, heart rate, and blood glucose in patients with diabetes) but worse blood pressure control. The clinical profile of patients with chronic ischemic heart disease is similar in the 2 registries. There has been an improvement in patients' medical therapy and dyslipidemia control, blood glucose, and heart rate, but there is still much room for improvement in the control of other cardiovascular risk factors. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  20. A nested case-control approach to interactions between radiation dose and other factors as causes of cancer

    International Nuclear Information System (INIS)

    Land, Charles E.

    1992-04-01

    Often a nested case-control study is the most practicable approach to estimating the interaction of two cancer risk factors in a large cohort. If one of the factors has already been evaluated for the entire cohort, however, more information is already available about its relationship to risk than could be obtained from a nested study. A modified case-control approach is proposed, in which information about the second, unknown factor is sought for cases and controls matched on the first factor. The approach requires, for interaction models other than the multiplicative, a nonstandard analytical approach incorporating cohort-based information about the first factor. The problem is discussed in the context of breast cancer risk in a defined cohort of female Japanese atomic bomb survivors, in relation to radiation dose and reproductive history. (author)

  1. Granulocyte colony-stimulating factor increases CD4+ T cell counts of human immunodeficiency virus-infected patients receiving stable, highly active antiretroviral therapy

    DEFF Research Database (Denmark)

    Aladdin, H; Ullum, H; Dam Nielsen, S.

    2000-01-01

    Thirty human immunodeficiency virus (HIV)-infected patients with CD4+ T cell counts active antiretroviral therapy (HAART) for at least 24 weeks were randomized to receive either placebo or granulocyte colony-stimulating factor (G-CSF; 0.3 mg/mL 3 times...... counts resulted from increases in CD45RO+ memory T cells and cells expressing the CD38 activation marker. Lymphocyte proliferative responses to phytohemagglutinin and Candida antigen decreased, whereas NK cell activity and plasma HIV RNA did not change during G-CSF treatment. After 24 weeks, all immune...... a week) for 12 weeks. Blood samples were collected at specified time points. G-CSF treatment enhanced the total lymphocyte count (P=.002) and increased CD3+ (P=.005), CD4+ (P=.03), and CD8+ (P=.004) T cell counts as well as numbers of CD3-CD16+CD56+ NK cells (P=.001). The increases in CD4+ and CD8+ cell...

  2. Retrospective analysis of 104 histologically proven adult brainstem gliomas: clinical symptoms, therapeutic approaches and prognostic factors

    International Nuclear Information System (INIS)

    Reithmeier, Thomas; Kuzeawu, Aanyo; Hentschel, Bettina; Loeffler, Markus; Trippel, Michael; Nikkhah, Guido

    2014-01-01

    Adult brainstem gliomas are rare primary brain tumors (<2% of gliomas). The goal of this study was to analyze clinical, prognostic and therapeutic factors in a large series of histologically proven brainstem gliomas. Between 1997 and 2007, 104 patients with a histologically proven brainstem glioma were retrospectively analyzed. Data about clinical course of disease, neuropathological findings and therapeutic approaches were analyzed. The median age at diagnosis was 41 years (range 18-89 years), median KPS before any operative procedure was 80 (range 20-100) and median survival for the whole cohort was 18.8 months. Histopathological examinations revealed 16 grade I, 31 grade II, 42 grade III and 14 grade IV gliomas. Grading was not possible in 1 patient. Therapeutic concepts differed according to the histopathology of the disease. Median overall survival for grade II tumors was 26.4 months, for grade III tumors 12.9 months and for grade IV tumors 9.8 months. On multivariate analysis the relative risk to die increased with a KPS ≤ 70 by factor 6.7, with grade III/IV gliomas by the factor 1.8 and for age ≥ 40 by the factor 1.7. External beam radiation reduced the risk to die by factor 0.4. Adult brainstem gliomas present with a wide variety of neurological symptoms and postoperative radiation remains the cornerstone of therapy with no proven benefit of adding chemotherapy. Low KPS, age ≥ 40 and higher tumor grade have a negative impact on overall survival

  3. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...... Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...

  4. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  5. Integrated modeling and experimental approach for determining transcription factor profiles from fluorescent reporter data

    Directory of Open Access Journals (Sweden)

    Jayaraman Arul

    2008-07-01

    Full Text Available Abstract Background The development of quantitative models of signal transduction, as well as parameter estimation to improve existing models, depends on the ability to obtain quantitative information about various proteins that are part of the signaling pathway. However, commonly-used measurement techniques such as Western blots and mobility shift assays provide only qualitative or semi-quantitative data which cannot be used for estimating parameters. Thus there is a clear need for techniques that enable quantitative determination of signal transduction intermediates. Results This paper presents an integrated modeling and experimental approach for quantitatively determining transcription factor profiles from green fluorescent protein (GFP reporter data. The technique consists of three steps: (1 creating data sets for green fluorescent reporter systems upon stimulation, (2 analyzing the fluorescence images to determine fluorescence intensity profiles using principal component analysis (PCA and K-means clustering, and (3 computing the transcription factor concentration from the fluorescence intensity profiles by inverting a model describing transcription, translation, and activation of green fluorescent proteins. We have used this technique to quantitatively characterize activation of the transcription factor NF-κB by the cytokine TNF-α. In addition, we have applied the quantitative NF-κB profiles obtained from our technique to develop a model for TNF-α signal transduction where the parameters were estimated from the obtained data. Conclusion The technique presented here for computing transcription factor profiles from fluorescence microscopy images of reporter cells generated quantitative data on the magnitude and dynamics of NF-κB activation by TNF-α. The obtained results are in good agreement with qualitative descriptions of NF-κB activation as well as semi-quantitative experimental data from the literature. The profiles computed from

  6. From the big five to the general factor of personality: a dynamic approach.

    Science.gov (United States)

    Micó, Joan C; Amigó, Salvador; Caselles, Antonio

    2014-10-28

    An integrating and dynamic model of personality that allows predicting the response of the basic factors of personality, such as the Big Five Factors (B5F) or the general factor of personality (GFP) to acute doses of drug is presented in this paper. Personality has a dynamic nature, i.e., as a consequence of a stimulus, the GFP dynamics as well as each one of the B5F of personality dynamics can be explained by the same model (a system of three coupled differential equations). From this invariance hypothesis, a partial differential equation, whose solution relates the GFP with each one of the B5F, is deduced. From this dynamic approach, a co-evolution of the GFP and each one of the B5F occurs, rather than an unconnected evolution, as a consequence of the same stimulus. The hypotheses and deductions are validated through an experimental design centered on the individual, where caffeine is the considered stimulus. Thus, as much from a theoretical point of view as from an applied one, the models here proposed open a new perspective in the understanding and study of personality like a global system that interacts intimately with the environment, being a clear bet for the high level inter-disciplinary research.

  7. A culture of care: the French approach to cardiovascular risk factor management.

    Science.gov (United States)

    O'Brien Cherry, Colleen; Steichen, Olivier; Mathew, Anjali; Duhot, Didier; Hebbrecht, Gilles; Schuster, Richard J

    2012-01-01

    The objective of this study was to describe French primary care physicians' beliefs about cardiovascular disease (CVD) risk factors and best practices for managing CVD. This study comprised a purposive convenience sample of 656 primary care physicians in France, recruited from contacts made through the French Society of General Medicine. We compiled the physicians' responses to free text questions taken from an Internet-based survey and analyzed them using a qualitative approach. Physician's responses were inductively analyzed using content analysis. Responses were thematically coded, tabulated, and computed for frequencies. Overall themes and verbatim examples are presented in this article. The French physicians in our study are generally happy with their country's health care system and cite equity as the primary reason. Interestingly, along with food and lifestyle differences, they also cite equity of their health system as the reason for the lower CVD death rate in France, Japan, and Israel compared with the United States. The physicians believe that they are successful at managing CVD risk factors by emphasizing aspects of the doctor-patient relationship, including spending more time with patients and focusing on education. Physicians who are on the front line of care and management offer a fresh perspective on best practices for CVD prevention and management. The equity of the French health care system supports a "culture of care" in France that might lead to better outcomes for CVD risk factor patients than in the United States.

  8. Finite difference methods for option pricing under Lévy processes: Wiener-Hopf factorization approach.

    Science.gov (United States)

    Kudryavtsev, Oleg

    2013-01-01

    In the paper, we consider the problem of pricing options in wide classes of Lévy processes. We propose a general approach to the numerical methods based on a finite difference approximation for the generalized Black-Scholes equation. The goal of the paper is to incorporate the Wiener-Hopf factorization into finite difference methods for pricing options in Lévy models with jumps. The method is applicable for pricing barrier and American options. The pricing problem is reduced to the sequence of linear algebraic systems with a dense Toeplitz matrix; then the Wiener-Hopf factorization method is applied. We give an important probabilistic interpretation based on the infinitely divisible distributions theory to the Laurent operators in the correspondent factorization identity. Notice that our algorithm has the same complexity as the ones which use the explicit-implicit scheme, with a tridiagonal matrix. However, our method is more accurate. We support the advantage of the new method in terms of accuracy and convergence by using numerical experiments.

  9. A plastic stress intensity factor approach to turbine disk structural integrity assessment

    Directory of Open Access Journals (Sweden)

    V. Shlyannikov

    2016-07-01

    Full Text Available This study based on a new fracture mechanics parameter is concerned with assessing the integrity of cracked steam turbine disk which operate under startup-shutdown cyclic loading conditions. Damage accumulation and growth in service have occurred on the inner surface of slot fillet of key. In order to determine elastic-plastic fracture mechanics parameters full-size stress-strain state analysis of turbine disk was performed for a quote-elliptical part-through cracks under considering loading conditions. As a result distributions of elastic and plastic stress intensity factors along crack front in slot fillet of key of turbine disk depending on surface crack form are defined. An engineering approach to the prediction of carrying capacity of cracked turbine disk which is sensitive to the loading history at maintenance is proposed. The predictions of the rate of crack growth and residual lifetime of steam turbine disk are compared for elastic and elastic-plastic solutions. It is shown that the previously proposed elastic crack growth models provide overestimate the lifetime with respect to the present one. An advantage to use the plastic stress intensity factor to characterize the fracture resistance as the self-dependent unified parameter for a variety of turbine disk configurations rather than the magnitude of the elastic stress intensity factors alone is discussed.

  10. The constellation of dietary factors in adolescent acne: a semantic connectivity map approach.

    Science.gov (United States)

    Grossi, E; Cazzaniga, S; Crotti, S; Naldi, L; Di Landro, A; Ingordo, V; Cusano, F; Atzori, L; Tripodi Cutrì, F; Musumeci, M L; Pezzarossa, E; Bettoli, V; Caproni, M; Bonci, A

    2016-01-01

    Different lifestyle and dietetic factors have been linked with the onset and severity of acne. To assess the complex interconnection between dietetic variables and acne. This was a reanalysis of data from a case-control study by using a semantic connectivity map approach. 563 subjects, aged 10-24 years, involved in a case-control study of acne between March 2009 and February 2010, were considered in this study. The analysis evaluated the link between a moderate to severe acne and anthropometric variables, family history and dietetic factors. Analyses were conducted by relying on an artificial adaptive system, the Auto Semantic Connectivity Map (AutoCM). The AutoCM map showed that moderate-severe acne was closely associated with family history of acne in first degree relatives, obesity (BMI ≥ 30), and high consumption of milk, in particular skim milk, cheese/yogurt, sweets/cakes, chocolate, and a low consumption of fish, and limited intake of fruits/vegetables. Our analyses confirm the link between several dietetic items and acne. When providing care, dermatologists should also be aware of the complex interconnection between dietetic factors and acne. © 2014 European Academy of Dermatology and Venereology.

  11. ASSESMENT OF RISK FACTORS DIAGNOSTIC APPROACH AND MANAGEMENT IN CASES UNDERGOING DIFFICULT CHOLECYSTECTOMIES

    Directory of Open Access Journals (Sweden)

    Chandak

    2015-03-01

    Full Text Available BACKGROUND: Laparoscopic cholecystectomy is the standard of care for the treatment of symptomatic gallbladder disease and one of the most common procedures being performed by the general surgeons all over the world. With more and more endeavors being made in the field of laparoscopy , more and more complicated cases which were relatively contraindicated a few years ago , are now being tackled laparos copically. AIM: Aims of this study is assessment of risk factors , diagnostic approach and management of cases undergoing difficult cholecystectomies on basis of clinical , USG , preoperative , intra operative findings , duration of surgery , rate of conversion , post op complications and duration of stay in hospital. MATERIAL & METHODS: Prospective study done from J une 2012 to N ov . 2014 , 192 cases undergoing laproscopic cholecystectomy included in study at tertiary care hospital. RESULT: Cholecystitis or pancreat itis and thickened GB wall , PREOP ERCP are found to be significantly associated with increased risk of conversion. Obesity (BMI≥30 kg/m 2 was significantly associated with difficulty in access to the peritoneal cavity. Various factors. CONCLUSION: clinical factors like male sex , previous acute cholecystitis or pancreatitis and ultrasonographic finding of gall bladder wall thickness ≥ 4 mm can help to predict difficult laparoscopic cholecystectomy and likelihood of conversion of laparoscopic cholecystectomy t o open cholecystectomy

  12. Multi-factor challenge/response approach for remote biometric authentication

    Science.gov (United States)

    Al-Assam, Hisham; Jassim, Sabah A.

    2011-06-01

    Although biometric authentication is perceived to be more reliable than traditional authentication schemes, it becomes vulnerable to many attacks when it comes to remote authentication over open networks and raises serious privacy concerns. This paper proposes a biometric-based challenge-response approach to be used for remote authentication between two parties A and B over open networks. In the proposed approach, a remote authenticator system B (e.g. a bank) challenges its client A who wants to authenticate his/her self to the system by sending a one-time public random challenge. The client A responds by employing the random challenge along with secret information obtained from a password and a token to produce a one-time cancellable representation of his freshly captured biometric sample. The one-time biometric representation, which is based on multi-factor, is then sent back to B for matching. Here, we argue that eavesdropping of the one-time random challenge and/or the resulting one-time biometric representation does not compromise the security of the system, and no information about the original biometric data is leaked. In addition to securing biometric templates, the proposed protocol offers a practical solution for the replay attack on biometric systems. Moreover, we propose a new scheme for generating a password-based pseudo random numbers/permutation to be used as a building block in the proposed approach. The proposed scheme is also designed to provide protection against repudiation. We illustrate the viability and effectiveness of the proposed approach by experimental results based on two biometric modalities: fingerprint and face biometrics.

  13. Automatic Sky View Factor Estimation from Street View Photographs—A Big Data Approach

    Directory of Open Access Journals (Sweden)

    Jianming Liang

    2017-04-01

    Full Text Available Hemispherical (fisheye photography is a well-established approach for estimating the sky view factor (SVF. High-resolution urban models from LiDAR and oblique airborne photogrammetry can provide continuous SVF estimates over a large urban area, but such data are not always available and are difficult to acquire. Street view panoramas have become widely available in urban areas worldwide: Google Street View (GSV maintains a global network of panoramas excluding China and several other countries; Baidu Street View (BSV and Tencent Street View (TSV focus their panorama acquisition efforts within China, and have covered hundreds of cities therein. In this paper, we approach this issue from a big data perspective by presenting and validating a method for automatic estimation of SVF from massive amounts of street view photographs. Comparisons were made with SVF estimates derived from two independent sources: a LiDAR-based Digital Surface Model (DSM and an oblique airborne photogrammetry-based 3D city model (OAP3D, resulting in a correlation coefficient of 0.863 and 0.987, respectively. The comparisons demonstrated the capacity of the proposed method to provide reliable SVF estimates. Additionally, we present an application of the proposed method with about 12,000 GSV panoramas to characterize the spatial distribution of SVF over Manhattan Island in New York City. Although this is a proof-of-concept study, it has shown the potential of the proposed approach to assist urban climate and urban planning research. However, further development is needed before this approach can be finally delivered to the urban climate and urban planning communities for practical applications.

  14. Efficient expression of stable recombinant human insulin-like growth factor-1 fusion with human serum albumin in Chinese hamster ovary cells.

    Science.gov (United States)

    Wan, Aini; Xu, Dongsheng; Liu, Kedong; Peng, Lin; Cai, Yanfei; Chen, Yun; He, Yang; Yang, Jianfeng; Jin, Jian; Li, Huazhong

    2017-08-09

    Insulin-like growth factor-1 (IGF-1) plays a crucial role in cell development, differentiation, and metabolism, and has been a potential therapeutic agent for many diseases. Chinese hamster ovary (CHO) cells are widely used for production of recombinant therapeutic proteins, but the expression level of IGF-1 in CHO cells is very low (1,500 µg/L) and the half-life of IGF-1 in blood circulation is only 4.5 min according to previous studies. Therefore, IGF-1 was fused to long-circulating serum protein human serum albumin (HSA) and expressed in CHO cells. After 8-day fed-batch culture, the expression level of HSA-IGF-1 reached 100 mg/L. The fusion protein HSA-IGF-1 was purified with a recovery of 35% using a two-step chromatographic procedure. According to bioactivity assay, the purified HSA-IGF-1 could stimulate the proliferation of NIH3T3 cells in a dose-dependent fashion and promote the cell-cycle progression. Besides this, HSA-IGF-1 could bind to IGF-1 receptor on cell membrane and activate the intracellular PI3K/AKT signaling pathway. Our study suggested that HSA fusion technology carried out in CHO cells not only provided bioactivity in HSA-IGF-1 for further research but also offered a beneficial strategy to produce other similar cytokines in CHO cells.

  15. A knowledge-based approach for C-factor mapping in Spain using Landsat TM and GIS

    DEFF Research Database (Denmark)

    Veihe (former Folly), Anita; Bronsveld, M.C.; Clavaux, M

    1996-01-01

    The cover and management factor (C) in the Universal Soil Loss Equation (USLE), is one of the most important parameters for assessing erosion. In this study it is shown how a knowledge-based approach can be used to optimize C-factor mapping in the Mediterranean region being characterized by unhom......The cover and management factor (C) in the Universal Soil Loss Equation (USLE), is one of the most important parameters for assessing erosion. In this study it is shown how a knowledge-based approach can be used to optimize C-factor mapping in the Mediterranean region being characterized...

  16. Analysing Stable Time Series

    National Research Council Canada - National Science Library

    Adler, Robert

    1997-01-01

    We describe how to take a stable, ARMA, time series through the various stages of model identification, parameter estimation, and diagnostic checking, and accompany the discussion with a goodly number...

  17. New scalable transfer factors: a study of the key processes affecting soil-to-plant transfer factors and the development of a new scalable approach

    International Nuclear Information System (INIS)

    Tompkins, J.A.; Wadey, P.; Bell, J.N.B.; Butler, A.P.; Shaw, G.; Wheater, H.S.

    1998-01-01

    Transfer factors can differ widely even for the same conditions and this has cast doubt upon their applicability. The major drawback of transfer factors is that they do not explicitly represent the physical, chemical and biological processes affecting soil-to-plant transfer of radionuclides, but contain aggregated information on a number of such processes. The paper aims to identify the key processes, affecting radionuclide transport, that are contained within the soil-to-plant transfer factor values for generic soil and crop types. It also presents the values obtained by applying various methods for transfer factor calculation and looks at developing a new approach in which transfer factors are estimated by reference to the underlying mechanistic processes. This approach is applied to a range of soil and crop data from lysimeter and column experiments of radionuclide migration

  18. The potential role of herbal medicines in the treatment of chronic stable angina pectoris: a review of key herbs, and as illustration, exploration of the Chinese herbal medicine approach

    Directory of Open Access Journals (Sweden)

    O'Brien KA

    2012-12-01

    Full Text Available Kylie A O'Brien,1,2 Luis Vitetta31Deakin University, Melbourne, Victoria, Australia; 2Monash Medical School, Prahran, Victoria, Australia; 3The University of Queensland, School of Medicine, Centre for Integrative Clinical and Molecular Medicine at the Princess Alexandra Hospital, Brisbane, Queensland, AustraliaAbstract: Herbal medicines have been used for centuries within different cultures to treat cardiovascular disease, including stable angina pectoris. However, the use of herbs varies within traditions of natural medicine, and how they are understood to work in systems such as Chinese medicine, for example, is vastly different from the pharmaceutical model that seeks to reduce herbs to their active constituents. This review first discusses, individually, key herbs used within Western, Indian, and Chinese herbalism to treat stable angina pectoris and their main active constituents and pharmacological actions. The second part of the paper then specifically explores how angina is treated traditionally with Chinese herbal medicine, a unique approach to the understanding of health and illness underpinned by philosophies and theories that describe the physiological functioning and pathological changes in the body in terms very different from those of biomedicine. A foundational account of the guiding theories of Chinese medicine is followed by a description of the cardiovascular system and the etiology and pathogenesis of angina from the Chinese medical perspective. This forms the basis for understanding the rationale for construction of Chinese herbal medicinal formulae for treating angina pectoris. The scientific evidence of the efficacy of some Chinese herbal formulae is discussed.Keywords: herbs, herbal medicine, Chinese herbal medicine, angina pectoris, cardiovascular

  19. A Systematic Approach to Identify Candidate Transcription Factors that Control Cell Identity

    Directory of Open Access Journals (Sweden)

    Ana C. D’Alessio

    2015-11-01

    Full Text Available Hundreds of transcription factors (TFs are expressed in each cell type, but cell identity can be induced through the activity of just a small number of core TFs. Systematic identification of these core TFs for a wide variety of cell types is currently lacking and would establish a foundation for understanding the transcriptional control of cell identity in development, disease, and cell-based therapy. Here, we describe a computational approach that generates an atlas of candidate core TFs for a broad spectrum of human cells. The potential impact of the atlas was demonstrated via cellular reprogramming efforts where candidate core TFs proved capable of converting human fibroblasts to retinal pigment epithelial-like cells. These results suggest that candidate core TFs from the atlas will prove a useful starting point for studying transcriptional control of cell identity and reprogramming in many human cell types.

  20. Psychosomatic Factors and Psychologic Status in Psoriatic Patients and Approach to the Psoriatic Patients

    Directory of Open Access Journals (Sweden)

    Ertuğrul H. Aydemir

    2008-12-01

    Full Text Available Even if it has not been completely proven, psychosomatic factors are generally agreed and most of the patients talk about stress and the other emotional traumas at the beginning of disease and at the attacks. Furthermore since it is a difficult to treat disease easily seen on the skin, cause to hopeless, loneliness and isolation senses and they feel theirselves dirty and guilty. Then it leads to an unbreakable vicious circle. It is very important to make an approach with much care and affection. It is very important that to listen, to examine and to touch the dermatologist to the patient with patience and affection. Besides that to take a psychiatric support may also help too much to the treatment of the diseases.

  1. Factors Affecting M-commerce Adoption in Oman using Technology Acceptance Modeling Approach

    Directory of Open Access Journals (Sweden)

    Syed Jafar Naqvi

    2014-11-01

    Full Text Available The advancement in mobile technologies has influenced many countries to adopt mobile services in their private and public organizations including Oman. M-commerce services are growing rapidly with the exponential growth of mobile devices, technologies and networks. Hence, many business organizations private or public use them to improve revenue, reduce costs, maintain their competitive edge and achieve a level of high efficiency. Although there were many M-commerce services introduced, it was hard to find evidence of any study conducted to determine their successes or failures. This study is an attempt to explore the factors affecting the adoption of M-commerce services in Oman using the Technology Acceptance Model (TAM approach.

  2. Computational Modelling Approaches on Epigenetic Factors in Neurodegenerative and Autoimmune Diseases and Their Mechanistic Analysis

    Directory of Open Access Journals (Sweden)

    Afroza Khanam Irin

    2015-01-01

    Full Text Available Neurodegenerative as well as autoimmune diseases have unclear aetiologies, but an increasing number of evidences report for a combination of genetic and epigenetic alterations that predispose for the development of disease. This review examines the major milestones in epigenetics research in the context of diseases and various computational approaches developed in the last decades to unravel new epigenetic modifications. However, there are limited studies that systematically link genetic and epigenetic alterations of DNA to the aetiology of diseases. In this work, we demonstrate how disease-related epigenetic knowledge can be systematically captured and integrated with heterogeneous information into a functional context using Biological Expression Language (BEL. This novel methodology, based on BEL, enables us to integrate epigenetic modifications such as DNA methylation or acetylation of histones into a specific disease network. As an example, we depict the integration of epigenetic and genetic factors in a functional context specific to Parkinson’s disease (PD and Multiple Sclerosis (MS.

  3. A generalized linear factor model approach to the hierarchical framework for responses and response times.

    Science.gov (United States)

    Molenaar, Dylan; Tuerlinckx, Francis; van der Maas, Han L J

    2015-05-01

    We show how the hierarchical model for responses and response times as developed by van der Linden (2007), Fox, Klein Entink, and van der Linden (2007), Klein Entink, Fox, and van der Linden (2009), and Glas and van der Linden (2010) can be simplified to a generalized linear factor model with only the mild restriction that there is no hierarchical model at the item side. This result is valuable as it enables all well-developed modelling tools and extensions that come with these methods. We show that the restriction we impose on the hierarchical model does not influence parameter recovery under realistic circumstances. In addition, we present two illustrative real data analyses to demonstrate the practical benefits of our approach. © 2014 The British Psychological Society.

  4. Factors Affecting the Adoption of Gamified Smart Tourism Applications: An Integrative Approach

    Directory of Open Access Journals (Sweden)

    Changsok Yoo

    2017-11-01

    Full Text Available Considering that the core concerns in sustainability are threats to the survival of humankind and the ecosystems that humans depend on, changing the consumption and production behaviors of individuals and society is inevitable. However, people are reluctant to change their own behavior in support of sustainability goals. This tendency seems to be especially strong in tourism because the main value of tourism is hedonic utility. Thus, the tourism industry is now introducing gamification and smart tourism to shift tourist behavior toward sustainability, but most of studies and practices only focus on the performance and application of gamification without considering customer adoption patterns and perceptions during the process. This study empirically investigated what factors affect the adoption of smart tourism applications that incorporate game elements, using the Google Maps tourist guide program. As an initial approach, we incorporated diverse theoretical approaches: perceived usefulness; perceived ease of use; perceived enjoyment from technology acceptance model; information and interaction motivations from the uses and gratifications theory; the network effect; distributive justice; flow as responses to the game characteristics of smart tourism applications; and information privacy concerns as a negative factor for diffusion. The result showed that hedonic characteristics of the gamified smart tourism application (GSTA are strong in adoption. Perceived enjoyment had a significant influence on the intention to use, but information quality, related to cognitive experience, did not. The flow and perceived distributive justice associated with the game content were not significant, but the interaction motivation was significant in the research model. The results of this study show that individuals regard a GSTA as a low-level game tool. Also, it is important to preoccupy the smart tourism application market in terms of marketing strategy because

  5. Local Recurrence After Primary Proton Beam Therapy in Uveal Melanoma: Risk Factors, Retreatment Approaches, and Outcome.

    Science.gov (United States)

    Seibel, Ira; Cordini, Dino; Rehak, Matus; Hager, Annette; Riechardt, Aline I; Böker, Alexander; Heufelder, Jens; Weber, Andreas; Gollrad, Johannes; Besserer, Angela; Joussen, Antonia M

    2015-10-01

    To evaluate the risk factors, recurrence rates, retreatments, and long-term patient outcomes following proton beam therapy for uveal melanoma. Retrospective interventional case series. All patients treated with primary proton beam therapy for uveal melanoma at the oncology service at Charité-Berlin and Helmholtz-Zentrum-Berlin between May 1998 and December 2008 were reviewed for local recurrence. Of 982 patients, 982 eyes matched the inclusion criteria. The data were obtained from electronic health records, operative reports, discharge letters, and radiation planning. Comparisons of fundus photographs and ultrasound measurements were performed to assess the growth pattern of the tumor and to determine the success of retreatment, in the case that a globe-retaining therapy was undertaken. Of 982 patients, 35 patients (3.6%) developed local recurrence. The median follow-up was 60.7 months (6.0-170.4 months). Local control rate was 96.4% and the overall eye retention rate was 95.0% in this cohort. Local recurrence was correlated with a higher risk for metastasis and reduced survival. Largest tumor diameter was identified as the sole statistically significant risk factor for local recurrence (P = .00001). All globe-retaining retreatment approaches for local recurrence, including proton beam therapy, brachytherapy, and transpupillary thermotherapy used for recurrences at the tumor margins, showed good local tumor control and similar metastasis-free survivals. This study showed that each globe-retaining retreatment approach can result in satisfying local tumor control. In case of early detection of local recurrence, preservation of the globe can be warranted. Therefore, regularly performed follow-ups should be ensured. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Distance Factors and Croatian Export Obstacles in the EU15: CAGE Approach

    Directory of Open Access Journals (Sweden)

    Helena Miloloža

    2015-07-01

    Full Text Available For long-term sustainability of any enterprise, it is required to observe each market separately and systematically modify business approach to prevailing conditions in each. However, adaptation to each market can be a complex affair that requires certain financial costs but ignoring distinguishing criteria leads to reduction in revenues and undermines long-term profitability. Time saving and cost-effectiveness can be achieved by application of The CAGE Distance Framework – a model that analysis all diversities between two or more countries. Croatia did not yet utilize the benefits that European Union membership provides nor did significantly improved its international business. It is obvious that Croatia faces difficulties in the strategic approach to prospective foreign markets. Therefore, emphasis of this article is on analysis and identification of the distinguishing factors between Croatia and the EU15 in order to facilitate and enhance cooperation among them in the future. Throughout the analysis of Croatian export from the beginning of the economic crisis, this article gives an overview of international collaboration among Croatia and the EU15 and comparative analysis by using The CAGE Distance Framework. This analysis has confirmed significant fluctuations, unexploited potential and problems of the Croatian economy in all dimensions of The CAGE model.

  7. Perspective on Human and Organizational Factors (HOF) - Attempt of a Systemic Approach

    International Nuclear Information System (INIS)

    Meynen, F.

    2016-01-01

    The presentation will raise questions concerning current conceptions and practices related to human and organizational factors and will focus on the need of a more systemic view and approaches in the nuclear industry. In practice, attention is often focused unilaterally on technical aspects, neglecting the interactions and interfaces between the organization, the people and the technology. The work in the different areas takes place with different approaches, based on different technical backgrounds but also on different cultures of the country, the company, the plant, etc. Also within the concept of defence-in-depth the attention normally lies on the technical safety levels, although similar provisions exist in the organizational field. While the technical systems are always evolving and their reliability increases, the question of their implications for the organizations and the people who work with these systems is not always analysed in depth. Also, it should not be focused only on the staff in the control room. Attention must be directed also to the support organizations (maintenance, analysis, monitoring, etc.) and to the manufacturer, which play a significant and sometimes underestimated role in the overall system as well. Further, there is a tendency to reduce the complexity by looking at individual aspects such as “safety culture”, “resilience”, “management systems”, “training”, “organizational structure”, etc., often without going beyond into a systemic approach. This requires the involvement of all different disciplines. Hence, dealing with the issue of HOF also means creating a basis to understand the complexity of the interactions between human, organizational and technical aspects. For this a very good knowledge and solid experience in these different fields are required. The presentation will give some examples from other industries and the three major nuclear accidents of Three Mile Island, Chernobyl and Fukushima as an

  8. Biomechanical approaches to identify and quantify injury mechanisms and risk factors in women's artistic gymnastics.

    Science.gov (United States)

    Bradshaw, Elizabeth J; Hume, Patria A

    2012-09-01

    Targeted injury prevention strategies, based on biomechanical analyses, have the potential to help reduce the incidence and severity of gymnastics injuries. This review outlines the potential benefits of biomechanics research to contribute to injury prevention strategies for women's artistic gymnastics by identification of mechanisms of injury and quantification of the effects of injury risk factors. One hundred and twenty-three articles were retained for review after searching electronic databases using key words, including 'gymnastic', 'biomech*', and 'inj*', and delimiting by language and relevance to the paper aim. Impact load can be measured biomechanically by the use of instrumented equipment (e.g. beatboard), instrumentation on the gymnast (accelerometers), or by landings on force plates. We need further information on injury mechanisms and risk factors in gymnastics and practical methods of monitoring training loads. We have not yet shown, beyond a theoretical approach, how biomechanical analysis of gymnastics can help reduce injury risk through injury prevention interventions. Given the high magnitude of impact load, both acute and accumulative, coaches should monitor impact loads per training session, taking into consideration training quality and quantity such as the control of rotation and the height from which the landings are executed.

  9. MMOSA – A new approach of the human and organizational factor analysis in PSA

    International Nuclear Information System (INIS)

    Farcasiu, M.; Prisecaru, I.

    2014-01-01

    The results of many Probabilistic Safety Assessment (PSA) studies show a very significant contribution of human errors to nuclear installations failure. This paper is intended to analyze both the human performance importance in PSA studies and the elements that influence it. Starting from Man–Machine–Organization System (MMOS) concept a new approach (MMOSA) was developed to allow an explicit incorporation of the human and organizational factor in PSA studies. This method uses old techniques from Human Reliability Analysis (HRA) methods (THERP, SPAR-H) and new techniques to analyze human performance. The main novelty included in MMOSA is the identification of the machine–organization interfaces (maintenance, modification and aging management plan and state of man–machine interface) and the human performance evaluation based on them. A detailed result of the Human Performance Analysis (HPA) using the MMOSA methodology can identify any serious deficiencies of human performance which can usually be corrected through the improvement of the related MMOS interfaces. - Highlights: • MMOSA allows the incorporation of the human and organizational factor in PSA. • The method uses old techniques and new techniques to analyze human performance. • The main novelty is the identification of the machine–organization interfaces. • The MMOSA methodology identifies any serious deficiencies which can be corrected

  10. Innovative Approaches for Immune Tolerance to Factor VIII in the Treatment of Hemophilia A

    Science.gov (United States)

    Sherman, Alexandra; Biswas, Moanaro; Herzog, Roland W.

    2017-01-01

    Hemophilia A (coagulation factor VIII deficiency) is a debilitating genetic disorder that is primarily treated with intravenous replacement therapy. Despite a variety of factor VIII protein formulations available, the risk of developing anti-dug antibodies (“inhibitors”) remains. Overall, 20–30% of patients with severe disease develop inhibitors. Current clinical immune tolerance induction protocols to eliminate inhibitors are not effective in all patients, and there are no prophylactic protocols to prevent the immune response. New experimental therapies, such as gene and cell therapies, show promising results in pre-clinical studies in animal models of hemophilia. Examples include hepatic gene transfer with viral vectors, genetically engineered regulatory T cells (Treg), in vivo Treg induction using immune modulatory drugs, and maternal antigen transfer. Furthermore, an oral tolerance protocol is being developed based on transgenic lettuce plants, which suppressed inhibitor formation in hemophilic mice and dogs. Hopefully, some of these innovative approaches will reduce the risk of and/or more effectively eliminate inhibitor formation in future treatment of hemophilia A. PMID:29225598

  11. The systems approach to error reduction: factors influencing inoculation injury reporting in the operating theatre.

    Science.gov (United States)

    Cutter, Jayne; Jordan, Sue

    2013-11-01

    To examine the frequency of, and factors influencing, reporting of mucocutaneous and percutaneous injuries in operating theatres. Surgeons and peri-operative nurses risk acquiring blood-borne viral infections during surgical procedures. Appropriate first-aid and prophylactic treatment after an injury can significantly reduce the risk of infection. However, studies indicate that injuries often go unreported. The 'systems approach' to error reduction relies on reporting incidents and near misses. Failure to report will compromise safety. A postal survey of all surgeons and peri-operative nurses engaged in exposure prone procedures in nine Welsh hospitals, face-to-face interviews with selected participants and telephone interviews with Infection Control Nurses. The response rate was 51.47% (315/612). Most respondents reported one or more percutaneous (183/315, 58.1%) and/or mucocutaneous injuries (68/315, 21.6%) in the 5 years preceding the study. Only 54.9% (112/204) reported every injury. Surgeons were poorer at reporting: 70/133 (52.6%) reported all or >50% of their injuries compared with 65/71 nurses (91.5%). Injuries are frequently under-reported, possibly compromising safety in operating theatres. A significant number of inoculation injuries are not reported. Factors influencing under-reporting were identified. This knowledge can assist managers in improving reporting and encouraging a robust safety culture within operating departments. © 2012 John Wiley & Sons Ltd.

  12. A macroepigenetic approach to identify factors responsible for the autism epidemic in the United States

    Directory of Open Access Journals (Sweden)

    Dufault Renee

    2012-04-01

    Full Text Available Abstract The number of children ages 6 to 21 in the United States receiving special education services under the autism disability category increased 91% between 2005 to 2010 while the number of children receiving special education services overall declined by 5%. The demand for special education services continues to rise in disability categories associated with pervasive developmental disorders. Neurodevelopment can be adversely impacted when gene expression is altered by dietary transcription factors, such as zinc insufficiency or deficiency, or by exposure to toxic substances found in our environment, such as mercury or organophosphate pesticides. Gene expression patterns differ geographically between populations and within populations. Gene variants of paraoxonase-1 are associated with autism in North America, but not in Italy, indicating regional specificity in gene-environment interactions. In the current review, we utilize a novel macroepigenetic approach to compare variations in diet and toxic substance exposure between these two geographical populations to determine the likely factors responsible for the autism epidemic in the United States.

  13. PRISM offers a comprehensive genomic approach to transcription factor function prediction

    KAUST Repository

    Wenger, A. M.

    2013-02-04

    The human genome encodes 1500-2000 different transcription factors (TFs). ChIP-seq is revealing the global binding profiles of a fraction of TFs in a fraction of their biological contexts. These data show that the majority of TFs bind directly next to a large number of context-relevant target genes, that most binding is distal, and that binding is context specific. Because of the effort and cost involved, ChIP-seq is seldom used in search of novel TF function. Such exploration is instead done using expression perturbation and genetic screens. Here we propose a comprehensive computational framework for transcription factor function prediction. We curate 332 high-quality nonredundant TF binding motifs that represent all major DNA binding domains, and improve cross-species conserved binding site prediction to obtain 3.3 million conserved, mostly distal, binding site predictions. We combine these with 2.4 million facts about all human and mouse gene functions, in a novel statistical framework, in search of enrichments of particular motifs next to groups of target genes of particular functions. Rigorous parameter tuning and a harsh null are used to minimize false positives. Our novel PRISM (predicting regulatory information from single motifs) approach obtains 2543 TF function predictions in a large variety of contexts, at a false discovery rate of 16%. The predictions are highly enriched for validated TF roles, and 45 of 67 (67%) tested binding site regions in five different contexts act as enhancers in functionally matched cells.

  14. Sequence2Vec: A novel embedding approach for modeling transcription factor binding affinity landscape

    KAUST Repository

    Dai, Hanjun

    2017-07-26

    Motivation: An accurate characterization of transcription factor (TF)-DNA affinity landscape is crucial to a quantitative understanding of the molecular mechanisms underpinning endogenous gene regulation. While recent advances in biotechnology have brought the opportunity for building binding affinity prediction methods, the accurate characterization of TF-DNA binding affinity landscape still remains a challenging problem. Results: Here we propose a novel sequence embedding approach for modeling the transcription factor binding affinity landscape. Our method represents DNA binding sequences as a hidden Markov model (HMM) which captures both position specific information and long-range dependency in the sequence. A cornerstone of our method is a novel message passing-like embedding algorithm, called Sequence2Vec, which maps these HMMs into a common nonlinear feature space and uses these embedded features to build a predictive model. Our method is a novel combination of the strength of probabilistic graphical models, feature space embedding and deep learning. We conducted comprehensive experiments on over 90 large-scale TF-DNA data sets which were measured by different high-throughput experimental technologies. Sequence2Vec outperforms alternative machine learning methods as well as the state-of-the-art binding affinity prediction methods.

  15. An evolutionary medicine approach to understanding factors that contribute to chronic obstructive pulmonary disease.

    Science.gov (United States)

    Aoshiba, Kazutetsu; Tsuji, Takao; Itoh, Masayuki; Yamaguchi, Kazuhiro; Nakamura, Hiroyuki

    2015-01-01

    Although many studies have been published on the causes and mechanisms of chronic obstructive pulmonary disease (COPD), the reason for the existence of COPD and the reasons why COPD develops in humans have hardly been studied. Evolutionary medical approaches are required to explain not only the proximate factors, such as the causes and mechanisms of a disease, but the ultimate (evolutionary) factors as well, such as why the disease is present and why the disease develops in humans. According to the concepts of evolutionary medicine, disease susceptibility is acquired as a result of natural selection during the evolutionary process of traits linked to the genes involved in disease susceptibility. In this paper, we discuss the following six reasons why COPD develops in humans based on current evolutionary medical theories: (1) evolutionary constraints; (2) mismatch between environmental changes and evolution; (3) co-evolution with pathogenic microorganisms; (4) life history trade-off; (5) defenses and their costs, and (6) reproductive success at the expense of health. Our perspective pursues evolutionary answers to the fundamental question, 'Why are humans susceptible to this common disease, COPD, despite their long evolutionary history?' We believe that the perspectives offered by evolutionary medicine are essential for researchers to better understand the significance of their work.

  16. Sequence2Vec: a novel embedding approach for modeling transcription factor binding affinity landscape.

    Science.gov (United States)

    Dai, Hanjun; Umarov, Ramzan; Kuwahara, Hiroyuki; Li, Yu; Song, Le; Gao, Xin

    2017-11-15

    An accurate characterization of transcription factor (TF)-DNA affinity landscape is crucial to a quantitative understanding of the molecular mechanisms underpinning endogenous gene regulation. While recent advances in biotechnology have brought the opportunity for building binding affinity prediction methods, the accurate characterization of TF-DNA binding affinity landscape still remains a challenging problem. Here we propose a novel sequence embedding approach for modeling the transcription factor binding affinity landscape. Our method represents DNA binding sequences as a hidden Markov model which captures both position specific information and long-range dependency in the sequence. A cornerstone of our method is a novel message passing-like embedding algorithm, called Sequence2Vec, which maps these hidden Markov models into a common nonlinear feature space and uses these embedded features to build a predictive model. Our method is a novel combination of the strength of probabilistic graphical models, feature space embedding and deep learning. We conducted comprehensive experiments on over 90 large-scale TF-DNA datasets which were measured by different high-throughput experimental technologies. Sequence2Vec outperforms alternative machine learning methods as well as the state-of-the-art binding affinity prediction methods. Our program is freely available at https://github.com/ramzan1990/sequence2vec. xin.gao@kaust.edu.sa or lsong@cc.gatech.edu. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

  17. Inclusive Higgs boson production at the LHC in the kT -factorization approach

    Science.gov (United States)

    Abdulov, N. A.; Lipatov, A. V.; Malyshev, M. A.

    2018-03-01

    We investigate the inclusive Higgs boson production in proton-proton collisions at the CERN LHC conditions using the kT-factorization approach. Our analysis is based on the dominant off-shell gluon-gluon fusion subprocess (where the transverse momenta of initial gluons are taken into account) and covers H →γ γ , H →Z Z*→4 l (where l =e , μ ) and H →W+W-→e±μ∓ν ν ¯ decay channels. The transverse momentum dependent (or unintegrated) gluon densities in a proton were derived from Ciafaloni-Catani-Fiorani-Marchesini equation, which resums large logarithmic terms proportional to ln s ˜ln 1 /x , important at high energies. As an alternative choice, we apply the Kimber-Martin-Ryskin prescription, where the transverse momentum dependent gluon density is constructed from the known conventional parton distributions. We estimate the theoretical uncertainties of our calculations and compare our results with next-to-next-to-leading-order plus next-to-next-to-leading-logarithmic ones obtained using collinear QCD factorization. Our predictions agree well with the latest experimental data taken by the CMS and ATLAS Collaborations at √{s }=8 and 13 TeV.

  18. Human and management factors in probabilistic risk analysis: the SAM approach and observations from recent applications

    Energy Technology Data Exchange (ETDEWEB)

    Elisabeth Pate-Cornell, M.; Murphy, Dean M

    1996-08-01

    Most severe industrial accidents have been shown to involve one or more human errors and these are generally rooted in management problems. The objective of this paper is to draw some conclusions from the experience that we have acquired from three different studies of this phenomenon: (1) the Piper Alpha accident including problems of operations management and fire risks on-board offshore platforms, (2) the management of the heat shield of the NASA space shuttle orbiter, and (3) the roots of patient risks in anaesthesia. This paper describes and illustrates the SAM approach (System-Action-Management) that was developed and used in these studies to link the probabilities of system failures to human and management factors. This SAM model includes: first, a probabilistic risk analysis of the physical system, second, an analysis of the decisions and actions that affect the probabilities of its basic events, and third, a study of the management factors that influence those decisions and actions. In the three initial studies, the analytical links (conditional probabilities) among these three submodels were coarsely quantified based on statistical data whenever available, or most often, on expert opinions. This paper describes some observations that were made across these three studies, for example, the importance of the informal reward system, the difficulties in the communication of uncertainties, the problems of managing resource constraints, and the safety implications of the short cuts that they often imply.

  19. Developing Student Housing Quality Scale in Higher Institutions of Learning: A Factor Analysis Approach

    Directory of Open Access Journals (Sweden)

    F. K. Bondinuba

    2013-01-01

    Full Text Available The researchers developed an instrument for measuring student housing quality (SHQ in Higher Institutions of Learning (HIL in Ghana. The paper sought to validate the student housing quality scale (SHOQUAL through factor analysis approach. 700 respondents were sampled from two public HIL in Ghana in a cross-sectional survey that used a self-administered structured questionnaire for data collection. Confirmatory factor fnalysis (CFA was conducted to detect the underlying latent variables that significantly determine SHQ in Ghanaian HIL. The findings indicate that four emerged SHQ dimensions relevant to the research context were labelled as follows: core facility quality, enabling facility quality, support facility quality, and cost of housing. The constructs in the derived model possess high reliability and validity. Student housing service providers could conveniently use the derived instrument items for measuring SHQ in HIL. Implications are discussed and limitations are noted. The paper contributes to the literature in the areas of models of service quality in student housing management in HIL.

  20. Identification and Ranking of Critical Success Factors of Knowledge Management Using Fuzzy Quality Function Deployment Approach: A Case Study

    Directory of Open Access Journals (Sweden)

    Ali Mohaghar

    2014-02-01

    Based on the information accessible for the researchers, this is one of the first works which evaluates the key factors of successful knowledge management through fuzzy quality function deployment approach. It is expected that the proposed method would represent appropriate tools for enterprises which have decided to implement knowledge management because it prioritizes the critical success factors based on the knowledge management outcomes.

  1. Risk Factors for Visual Field Progression in the Groningen Longitudinal Glaucoma Study : A Comparison of Different Statistical Approaches

    NARCIS (Netherlands)

    Wesselink, Christiaan; Marcus, Michael W.; Jansonius, Nomdo M.

    2012-01-01

    Purpose: To identify risk factors for visual field progression in glaucoma and to compare different statistical approaches with this risk factor analysis. Patients and Methods: We included 221 eyes of 221 patients. Progression was analyzed using Nonparametric Progression Analysis applied to Humphrey

  2. Factors associated with choice of approach for Group B streptococcus screening.

    Science.gov (United States)

    Sefty, H; Klivitsky, A; Bromberg, M; Dichtiar, R; Ami, M Ben; Shohat, T; Glatman-Freedman, A

    2016-01-01

    The crude rate of early-onset Group B streptococcus disease (EOGBS) in Israel has been consistently under 0.5 for 1000 live births for the past 8 years. The Israeli Ministry of Health has adapted the risk factor based approach for preventing EOGBS and universal bacteriological screening for GBS is not recommended. In spite of this policy, there are indications that many pregnant women in Israel undergo bacteriological screening for GBS. The objective of this study is to assess the rate and characteristics of pregnant women who undergo screening for group B streptococcus (GBS) colonization in Israel. Survey of expectant mothers who came to give birth in 29 delivery rooms throughout Israel during the month of July 2012 regarding GBS screening practice and demographics. A total of 2968 pregnant women participated in the assessment. Among them, 935 women (31.5 %) had been tested for GBS colonization. About 90 % of those women had no risk factors, only 542 women (60 %) underwent testing during the recommended gestational timing (35-37 weeks) and 23 % of the tested women reported being GBS carriers. GBS screening as part of the routine pregnancy follow- up was associated with: residence district, intermediate or high socioeconomic rank, being a member of certain health maintenance organization and being Jewish. Characteristics found to be significantly associated with being a GBS carrier were: low socioeconomic rank, and having a risk factor for GBS infection. A substantial number of pregnant women in Israel undergo screening for GBS colonization despite the national policy against universal screening. While GBS colonization was more prevalent in women of lower socioeconomic status, screening is done more often in those of higher socioeconomic status, suggesting unnecessary monetary expenses.

  3. Evaluation of approaches to monitor Staphylococcus aureus virulence factor expression during human disease.

    Directory of Open Access Journals (Sweden)

    Wouter Rozemeijer

    Full Text Available Staphylococcus aureus is a versatile pathogen of medical significance, using multiple virulence factors to cause disease. A prophylactic S. aureus 4-antigen (SA4Ag vaccine comprising capsular polysaccharide (types 5 and 8 conjugates, clumping factor A (ClfA and manganese transporter C (MntC is under development. This study was designed to characterize S. aureus isolates recovered from infected patients and also to investigate approaches for examining expression of S. aureus vaccine candidates and the host response during human infection. Confirmation of antigen expression in different disease states is important to support the inclusion of these antigens in a prophylactic vaccine. Hospitalized patients with diagnosed S. aureus wound (27 or bloodstream (24 infections were enrolled. Invasive and nasal carriage S. aureus isolates were recovered and characterized for genotypic diversity. S. aureus antigen expression was evaluated directly by real-time, quantitative, reverse-transcriptase PCR (qRT-PCR analysis and indirectly by serology using a competitive Luminex immunoassay. Study isolates were genotypically diverse and all had the genes encoding the antigens present in the SA4Ag vaccine. S. aureus nasal carriage was detected in 55% of patients, and in those subjects 64% of the carriage isolates matched the invasive strain. In swab samples with detectable S. aureus triosephosphate isomerase housekeeping gene expression, RNA transcripts encoding the S. aureus virulence factors ClfA, MntC, and capsule polysaccharide were detected by qRT-PCR. Antigen expression was indirectly confirmed by increases in antibody titer during the course of infection from acute to convalescent phase. Demonstration of bacterial transcript expression together with immunological response to the SA4Ag antigens in a clinically relevant patient population provides support for inclusion of these antigens in a prophylactic vaccine.

  4. A retrospective likelihood approach for efficient integration of multiple omics factors in case-control association studies.

    Science.gov (United States)

    Balliu, Brunilda; Tsonaka, Roula; Boehringer, Stefan; Houwing-Duistermaat, Jeanine

    2015-03-01

    Integrative omics, the joint analysis of outcome and multiple types of omics data, such as genomics, epigenomics, and transcriptomics data, constitute a promising approach for powerful and biologically relevant association studies. These studies often employ a case-control design, and often include nonomics covariates, such as age and gender, that may modify the underlying omics risk factors. An open question is how to best integrate multiple omics and nonomics information to maximize statistical power in case-control studies that ascertain individuals based on the phenotype. Recent work on integrative omics have used prospective approaches, modeling case-control status conditional on omics, and nonomics risk factors. Compared to univariate approaches, jointly analyzing multiple risk factors with a prospective approach increases power in nonascertained cohorts. However, these prospective approaches often lose power in case-control studies. In this article, we propose a novel statistical method for integrating multiple omics and nonomics factors in case-control association studies. Our method is based on a retrospective likelihood function that models the joint distribution of omics and nonomics factors conditional on case-control status. The new method provides accurate control of Type I error rate and has increased efficiency over prospective approaches in both simulated and real data. © 2015 Wiley Periodicals, Inc.

  5. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  6. Mathematical evaluation of similarity factor using various weighing approaches on aceclofenac marketed formulations by model-independent method.

    Science.gov (United States)

    Soni, T G; Desai, J U; Nagda, C D; Gandhi, T R; Chotai, N P

    2008-01-01

    The US Food and Drug Administration's (FDA's) guidance for industry on dissolution testing of immediate-release solid oral dosage forms describes that drug dissolution may be the rate limiting step for drug absorption in the case of low solubility/high permeability drugs (BCS class II drugs). US FDA Guidance describes the model-independent mathematical approach proposed by Moore and Flanner for calculating a similarity factor (f2) of dissolution across a suitable time interval. In the present study, the similarity factor was calculated on dissolution data of two marketed aceclofenac tablets (a BCS class II drug) using various weighing approaches proposed by Gohel et al. The proposed approaches were compared with a conventional approach (W = 1). On the basis of consideration of variability, preference is given in the order of approach 3 > approach 2 > approach 1 as approach 3 considers batch-to-batch as well as within-samples variability and shows best similarity profile. Approach 2 considers batch-to batch variability with higher specificity than approach 1.

  7. Understanding factors associated with the translation of cardiovascular research: a multinational case study approach

    Science.gov (United States)

    2014-01-01

    Background Funders of health research increasingly seek to understand how best to allocate resources in order to achieve maximum value from their funding. We built an international consortium and developed a multinational case study approach to assess benefits arising from health research. We used that to facilitate analysis of factors in the production of research that might be associated with translating research findings into wider impacts, and the complexities involved. Methods We built on the Payback Framework and expanded its application through conducting co-ordinated case studies on the payback from cardiovascular and stroke research in Australia, Canada and the United Kingdom. We selected a stratified random sample of projects from leading medical research funders. We devised a series of innovative steps to: minimize the effect of researcher bias; rate the level of impacts identified in the case studies; and interrogate case study narratives to identify factors that correlated with achieving high or low levels of impact. Results Twenty-nine detailed case studies produced many and diverse impacts. Over the 15 to 20 years examined, basic biomedical research has a greater impact than clinical research in terms of academic impacts such as knowledge production and research capacity building. Clinical research has greater levels of wider impact on health policies, practice, and generating health gains. There was no correlation between knowledge production and wider impacts. We identified various factors associated with high impact. Interaction between researchers and practitioners and the public is associated with achieving high academic impact and translation into wider impacts, as is basic research conducted with a clinical focus. Strategic thinking by clinical researchers, in terms of thinking through pathways by which research could potentially be translated into practice, is associated with high wider impact. Finally, we identified the complexity of

  8. Use of a human factors approach to uncover informatics needs of nurses in documentation of care.

    Science.gov (United States)

    Rogers, Michelle L; Sockolow, Paulina S; Bowles, Kathryn H; Hand, Kristin E; George, Jessie

    2013-11-01

    The success of health information technology implementations is often tied to the impact the technical system will have on the work of the clinicians using them. Considering the role of nurses in healthcare, it is shocking that there is a lack of evaluations of nursing information systems in the literature. Here we report on how a human factors approach can be used to address barriers and facilitators to use of the nursing information system (NIS). Human factors engineering (HFE) approaches provide the theoretical and methodological underpinning to address these socio-technical issues. This study investigated the use of an NIS, a module of the electronic health record (EHR) previously implemented throughout the hospital system. The study took place in two hospitals (760 beds and 300 beds) within a three-hospital health system. Earlier in the year, the NIS was implemented throughout the health system. We applied a scenario-based evaluation technique in order to understand the barriers and facilitators to nurse use of the NIS as part of improving the healthcare delivery system. The scenarios were designed to have the nurses interact with the major components of the NIS. The research team developed the standardized scenarios to cover the major functions of the system. Twelve nurses completed the study and results show that documentation within the NIS was hindered by several aspects of the interface. This paper discusses the themes associated with the usability of the NIS interface analyzing them using usability heuristics. The team also identified facilitators to use and proposed avenues to support or enhance these facilitators. This study examined the use of an NIS to standardize care and documentation in nursing. It used scenario-based usability testing, applying the "think-aloud" protocol technique to assess the use of the NIS in documenting patient care. This method of usability evaluation exposed an understanding of how nurses use the NIS and their perspective

  9. Exploring Barriers to Medication Safety in an Ethiopian Hospital Emergency Department: A Human Factors Engineering Approach

    Directory of Open Access Journals (Sweden)

    Ephrem Abebe

    2018-02-01

    Full Text Available Objective: To describe challenges associated with the medication use process and potential medication safety hazards in an Ethiopian hospital emergency department using a human factors approach. Methods: We conducted a qualitative study employing observations and semi-structured interviews guided by the Systems Engineering Initiative for Patient Safety model of work system as an analytical framework. The study was conducted in the emergency department of a teaching hospital in Ethiopia. Study participants included resident doctors, nurses, and pharmacists. We performed content analysis of the qualitative data using accepted procedures. Results: Organizational barriers included communication failures, limited supervision and support for junior staff contributing to role ambiguity and conflict. Compliance with documentation policy was minimal. Task related barriers included frequent interruptions and work-related stress resulting from job requirements to continuously prioritize the needs of large numbers of patients and family members. Person related barriers included limited training and work experience. Work-related fatigue due to long working hours interfered with staff’s ability to document and review medication orders. Equipment breakdowns were common as were non-calibrated or poorly maintained medical devices contributing to erroneous readings. Key environment related barriers included overcrowding and frequent interruption of staff’s work. Cluttering of the work space compounded the problem by impeding efforts to locate medications, medical supplies or medical charts. Conclusions: Applying a systems based approach allows a context specific understanding of medication safety hazards in EDs from low-income countries. When developing interventions to improve medication and overall patient safety, health leaders should consider the interactions of the different factors. Conflict of Interest We declare no conflicts of interest or

  10. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General ... Using some examples of classical games, we show how evolutionary game theory can help understand behavioural decisions of animals.

  11. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  12. Manifolds admitting stable forms

    Czech Academy of Sciences Publication Activity Database

    Le, Hong-Van; Panák, Martin; Vanžura, Jiří

    2008-01-01

    Roč. 49, č. 1 (2008), s. 101-11 ISSN 0010-2628 R&D Projects: GA ČR(CZ) GP201/05/P088 Institutional research plan: CEZ:AV0Z10190503 Keywords : stable forms * automorphism groups Subject RIV: BA - General Mathematics

  13. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  14. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  15. The stable subgroup graph

    Directory of Open Access Journals (Sweden)

    Behnaz Tolue

    2018-07-01

    Full Text Available In this paper we introduce stable subgroup graph associated to the group $G$. It is a graph with vertex set all subgroups of $G$ and two distinct subgroups $H_1$ and $H_2$ are adjacent if $St_{G}(H_1\\cap H_2\

  16. The effects of leadership and ward factors on job satisfaction in nursing homes: a multilevel approach.

    Science.gov (United States)

    Havig, Anders K; Skogstad, Anders; Veenstra, Marijke; Romøren, Tor I

    2011-12-01

    To examine (1) the relationships between job satisfaction and task- and relationship-oriented leadership and (2) the direct and moderating effects on job satisfaction of three ward-level factors: workload, use of teams and staff stability. Job satisfaction in nursing homes is vital to meeting the challenges related to recruitment and turnover. Cross-sectional design. A multilevel analysis approach was used to recognise a hierarchal structure of determined factors and to capture variation in job satisfaction at the individual and ward level. A questionnaire was sent to 444 registered nurses, auxiliary nurses and unskilled nursing assistants. Structured interviews were administered to 40 ward managers and 13 directors, and 900 hours of field observations was conducted in 40 nursing home wards throughout Norway. We found a significant relationship between job satisfaction and task-oriented and relationship-oriented leadership styles, with a stronger effect for task orientation. The effect of the two leadership styles varied significantly across wards. Furthermore, staff stability had both a significant positive direct effect and a moderating effect on job satisfaction, whereas the two other ward-level predictors yielded no significant contributions. The relatively stronger effect of task-oriented leadership on job satisfaction, particularly in wards with low staff stability, is in contrast to most previous studies and suggests that there may be specific conditions in nursing homes that favour the use of this leadership style. The varying effect of both leadership styles indicates that staff in different nursing home wards could benefit from the use of different leadership styles. The study highlights the importance of using different leadership behaviour and the importance of high staff stability to ensure job satisfaction among nursing home personnel. © 2011 Blackwell Publishing Ltd.

  17. Factors associated with the income distribution of full-time physicians: a quantile regression approach.

    Science.gov (United States)

    Shih, Ya-Chen Tina; Konrad, Thomas R

    2007-10-01

    Physician income is generally high, but quite variable; hence, physicians have divergent perspectives regarding health policy initiatives and market reforms that could affect their incomes. We investigated factors underlying the distribution of income within the physician population. Full-time physicians (N=10,777) from the restricted version of the 1996-1997 Community Tracking Study Physician Survey (CTS-PS), 1996 Area Resource File, and 1996 health maintenance organization penetration data. We conducted separate analyses for primary care physicians (PCPs) and specialists. We employed least square and quantile regression models to examine factors associated with physician incomes at the mean and at various points of the income distribution, respectively. We accounted for the complex survey design for the CTS-PS data using appropriate weighted procedures and explored endogeneity using an instrumental variables method. We detected widespread and subtle effects of many variables on physician incomes at different points (10th, 25th, 75th, and 90th percentiles) in the distribution that were undetected when employing regression estimations focusing on only the means or medians. Our findings show that the effects of managed care penetration are demonstrable at the mean of specialist incomes, but are more pronounced at higher levels. Conversely, a gender gap in earnings occurs at all levels of income of both PCPs and specialists, but is more pronounced at lower income levels. The quantile regression technique offers an analytical tool to evaluate policy effects beyond the means. A longitudinal application of this approach may enable health policy makers to identify winners and losers among segments of the physician workforce and assess how market dynamics and health policy initiatives affect the overall physician income distribution over various time intervals.

  18. A novel approach for transcription factor analysis using SELEX with high-throughput sequencing (TFAST.

    Directory of Open Access Journals (Sweden)

    Daniel J Reiss

    Full Text Available BACKGROUND: In previous work, we designed a modified aptamer-free SELEX-seq protocol (afSELEX-seq for the discovery of transcription factor binding sites. Here, we present original software, TFAST, designed to analyze afSELEX-seq data, validated against our previously generated afSELEX-seq dataset and a model dataset. TFAST is designed with a simple graphical interface (Java so that it can be installed and executed without extensive expertise in bioinformatics. TFAST completes analysis within minutes on most personal computers. METHODOLOGY: Once afSELEX-seq data are aligned to a target genome, TFAST identifies peaks and, uniquely, compares peak characteristics between cycles. TFAST generates a hierarchical report of graded peaks, their associated genomic sequences, binding site length predictions, and dummy sequences. PRINCIPAL FINDINGS: Including additional cycles of afSELEX-seq improved TFAST's ability to selectively identify peaks, leading to 7,274, 4,255, and 2,628 peaks identified in two-, three-, and four-cycle afSELEX-seq. Inter-round analysis by TFAST identified 457 peaks as the strongest candidates for true binding sites. Separating peaks by TFAST into classes of worst, second-best and best candidate peaks revealed a trend of increasing significance (e-values 4.5 × 10(12, 2.9 × 10(-46, and 1.2 × 10(-73 and informational content (11.0, 11.9, and 12.5 bits over 15 bp of discovered motifs within each respective class. TFAST also predicted a binding site length (28 bp consistent with non-computational experimentally derived results for the transcription factor PapX (22 to 29 bp. CONCLUSIONS/SIGNIFICANCE: TFAST offers a novel and intuitive approach for determining DNA binding sites of proteins subjected to afSELEX-seq. Here, we demonstrate that TFAST, using afSELEX-seq data, rapidly and accurately predicted sequence length and motif for a putative transcription factor's binding site.

  19. Three approaches for estimating recovery factors in carbon dioxide enhanced oil recovery

    Science.gov (United States)

    Verma, Mahendra K.

    2017-07-17

    PrefaceThe Energy Independence and Security Act of 2007 authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for carbon dioxide (CO2) and requested the USGS to estimate the “potential volumes of oil and gas recoverable by injection and sequestration of industrial carbon dioxide in potential sequestration formations” (42 U.S.C. 17271(b)(4)). Geologic CO2 sequestration associated with enhanced oil recovery (EOR) using CO2 in existing hydrocarbon reservoirs has the potential to increase the U.S. hydrocarbon recoverable resource. The objective of this report is to provide detailed information on three approaches that can be used to calculate the incremental recovery factors for CO2-EOR. Therefore, the contents of this report could form an integral part of an assessment methodology that can be used to assess the sedimentary basins of the United States for the hydrocarbon recovery potential using CO2-EOR methods in conventional oil reservoirs.

  20. The scientific assessment of combined effects of risk factors: different approaches in experimental biosciences and epidemiology.

    Science.gov (United States)

    Boedeker, Wolfgang; Backhaus, Thomas

    2010-08-01

    The analysis of combined effects of substances or risk factors has been a subject to science for more than a century. With different goals, combined effect analysis was addressed in almost all experimental biosciences. The major theoretical foundation can be traced back to two distinct origins. First, to the work by the pharmacologist Loewe on the concept of concentration additivity and second to the biometrician Bliss and the concept of independent action. In the search for a general solution and a unified terminology the interrelations of the concepts have extensively been studied and experimental findings reviewed. Meanwhile there seems to be consensus in experimental sciences that each concept has its role in predicting combined effect of agents and both are used for hazard und risk management. In contrast, epidemiologists describe combined effects mainly in terms of interactions in regression models. Although this approach started from a probabilistic model equivalent to the concept of independent action this origin is rarely acknowledged and effect summation is usually the preferred concept nowadays. Obscure biological meaning, the scale dependency of interaction terms as well as unavoidable residual confounding are taken as reasons why no new insights in combined effect analysis are likely to occur from epidemiology. In this paper we sketch the history of ideas and the state of the arts in combined effect analysis. We point to differences and common grounds in experimental biosciences and epidemiology.

  1. Time transfer capability of standard small form factor pluggable laser modules based on photon counting approach

    Science.gov (United States)

    Trojanek, Pavel; Prochazka, Ivan; Blazej, Josef

    2017-05-01

    We are reporting on timing parameters of commonly used standard Small Form Factor Pluggable (SFP) laser modules using single photon counting method. Photon counting is a promising approach for laser time transfer via optical fiber communication hardware. The sub-picosecond precision and stability may be achieved. We have performed several experiments with the aim to measure main parameters of the modules, such as time delay precision, time stability and temperature stability, all being critical for optical time transfer applications. Two standard 16 and 10 Gbit/s at 850 nm SFP modules were examined. The ultimate precision of possible time transfer of 800 fs for averaging times of hours was achieved. The modules together with their driving circuits exhibited very good temperature stability. The temperature drift as low as 300+/-200 fs/K was measured. The achieved timing parameters will enable to use the standard SFP modules for a new method of two way time transfer where the time differences between two distant time scales are measured in parallel to data transfer on existing optical data links without any communication interference.

  2. Risk factor investigation for cardiovascular health through WHO STEPS approach in Ardabil, Iran

    Directory of Open Access Journals (Sweden)

    Mashadi-Abdollahi H

    2011-07-01

    Full Text Available H Sadeghi-Bazargani1,2, H Jafarzadeh3, M Fallah4, S Hekmat3, J Bashiri3, GH Hosseingolizadeh3, MS Soltanmohammadzadeh3, A Mortezazadeh3, A Shaker3, M Danehzan3, A Zohouri3, O Khosravi3, R Nasimidoust3, N Malekpour3, E Kharazmi4, M Babaei3, M Nadirmohammadi3, H Mashhadi-Abdollahi51Neuroscience Research Center, 2Statistics and Epidemiology Department, Faculty of Health and Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran; 3Public Health Department, Ardabil University of Medical Sciences, Ardabil, Iran; 4Tampere School of Public Health, University of Tampere, Tampere, Finland; 5National Public Health Management Center (NPMC, Tabriz University of Medical Sciences, Tabriz, IranObjectives: Reliable evidence is the keystone for any noncommunicable disease (NCD prevention plan to be initiated. In this study we carried out a risk factor investigation based on the WHO Stepwise approach to Surveillance (STEPS.Methods: The study was conducted out on 1000 adults between 15 and 64 years of age living in Ardabil province, north-west Iran during 2006, based on the WHO STEPS approach to surveillance of risk factors for NCD. At this stage only the first and second steps were carried out. Data were collected through standard questionnaires and methods analyzed using STATA version 8 statistical software package.Results: 29.0% of men and 2.6% of women were current daily tobacco smokers. The mean number of manufactured cigarettes smoked per day was 18.9 among current daily smokers. Smoking was most prevalent among men of low-income families and those of lower education. The mean body mass index (BMI was 26.6 kg/m2, and was significantly correlated with systolic blood pressure. 58.9% were overweight or obese; 18.0% had raised blood pressure and 3.7% had isolated systolic hypertension. The mean number of servings of fruit consumed per day was 1.1; 33.1% had low levels of activity. Combined risk factor analysis showed that 4.1% of participants were in the

  3. Computation of External Quality Factors for RF Structures by Means of Model Order Reduction and a Perturbation Approach

    CERN Document Server

    Flisgen, Thomas; van Rienen, Ursula

    2016-01-01

    External quality factors are significant quantities to describe losses via waveguide ports in radio frequency resonators. The current contribution presents a novel approach to determine external quality factors by means of a two-step procedure: First, a state-space model for the lossless radio frequency structure is generated and its model order is reduced. Subsequently, a perturbation method is applied on the reduced model so that external losses are accounted for. The advantage of this approach results from the fact that the challenges in dealing with lossy systems are shifted to the reduced order model. This significantly saves computational costs. The present paper provides a short overview on existing methods to compute external quality factors. Then, the novel approach is introduced and validated in terms of accuracy and computational time by means of commercial software.

  4. Assessment of municipal infrastructure development and its critical influencing factors in urban China: A FA and STIRPAT approach.

    Science.gov (United States)

    Li, Yu; Zheng, Ji; Li, Fei; Jin, Xueting; Xu, Chen

    2017-01-01

    Municipal infrastructure is a fundamental facility for the normal operation and development of an urban city and is of significance for the stable progress of sustainable urbanization around the world, especially in developing countries. Based on the municipal infrastructure data of the prefecture-level cities in China, municipal infrastructure development is assessed comprehensively using a FA (factor analysis) model, and then the stochastic model STIRPAT (stochastic impacts by regression on population, affluence and technology) is examined to investigate key factors that influence municipal infrastructure of cities in various stages of urbanization and economy. This study indicates that the municipal infrastructure development in urban China demonstrates typical characteristics of regional differentiation, in line with the economic development pattern. Municipal infrastructure development in cities is primarily influenced by income, industrialization and investment. For China and similar developing countries under transformation, national public investment remains the primary driving force of economy as well as the key influencing factor of municipal infrastructure. Contribution from urbanization and the relative consumption level, and the tertiary industry is still scanty, which is a crux issue for many developing countries under transformation. With economic growth and the transformation requirements, the influence of the conventional factors such as public investment and industrialization on municipal infrastructure development would be expected to decline, meanwhile, other factors like the consumption and tertiary industry driven model and the innovation society can become key contributors to municipal infrastructure sustainability.

  5. Assessment of municipal infrastructure development and its critical influencing factors in urban China: A FA and STIRPAT approach.

    Directory of Open Access Journals (Sweden)

    Yu Li

    Full Text Available Municipal infrastructure is a fundamental facility for the normal operation and development of an urban city and is of significance for the stable progress of sustainable urbanization around the world, especially in developing countries. Based on the municipal infrastructure data of the prefecture-level cities in China, municipal infrastructure development is assessed comprehensively using a FA (factor analysis model, and then the stochastic model STIRPAT (stochastic impacts by regression on population, affluence and technology is examined to investigate key factors that influence municipal infrastructure of cities in various stages of urbanization and economy. This study indicates that the municipal infrastructure development in urban China demonstrates typical characteristics of regional differentiation, in line with the economic development pattern. Municipal infrastructure development in cities is primarily influenced by income, industrialization and investment. For China and similar developing countries under transformation, national public investment remains the primary driving force of economy as well as the key influencing factor of municipal infrastructure. Contribution from urbanization and the relative consumption level, and the tertiary industry is still scanty, which is a crux issue for many developing countries under transformation. With economic growth and the transformation requirements, the influence of the conventional factors such as public investment and industrialization on municipal infrastructure development would be expected to decline, meanwhile, other factors like the consumption and tertiary industry driven model and the innovation society can become key contributors to municipal infrastructure sustainability.

  6. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  7. Factores de riesgo de preeclampsia: enfoque inmunoendocrino. Parte II Risk factors for preeclampsia: immunoendocrine approach. Part II

    Directory of Open Access Journals (Sweden)

    Jeddú Cruz Hernández

    2008-03-01

    Full Text Available Esta segunda parte de la revisión trata sobre los nuevos factores de riesgo de la preeclampsia, también conocidos como emergentes, entre los cuales se incluyen fenómenos biológicos de tipo endocrino, inmunológico y relacionados con la disfunción endotelial, como el aumento del estrés oxidativo, la disminución de las vitaminas antioxidantes y otros. Se augura que estos factores de riesgo de reciente descripción tendrán que ser tenidos muy en cuenta en un futuro no lejano, si se quiere predecir eficazmente la aparición de la preeclampsia para poder actuar así de forma precoz durante el desarrollo de la enfermedad, y evitar al máximo sus consecuencias obstétricas adversas, y en algunos casos, hasta para prevenir el surgimiento de esta enfermedad.This second part of the review deals with the new risk factors for preeclampsia, which are also known as emergent, among which the biological phenomena of endocrine and immunological type and related to endothelial dysfunction, such as the increase of oxidative stress, the reduction of antioxidant vitamins and others, are included. It is said that these recently described risk factors will have to be taken into account in a near future to efficiently predict the appearance of preeclampsia to act early during the development of the disease and to prevent as much as possible its adverse obstetric consequences and, in some cases, to avoid the appearance of this disease.

  8. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  9. Connecting the Dots: State Health Department Approaches to Addressing Shared Risk and Protective Factors Across Multiple Forms of Violence

    Science.gov (United States)

    Wilkins, Natalie; Myers, Lindsey; Kuehl, Tomei; Bauman, Alice; Hertz, Marci

    2018-01-01

    Violence takes many forms, including intimate partner violence, sexual violence, child abuse and neglect, bullying, suicidal behavior, and elder abuse and neglect. These forms of violence are interconnected and often share the same root causes. They can also co-occur together in families and communities and can happen at the same time or at different stages of life. Often, due to a variety of factors, separate, “siloed” approaches are used to address each form of violence. However, understanding and implementing approaches that prevent and address the overlapping root causes of violence (risk factors) and promote factors that increase the resilience of people and communities (protective factors) can help practitioners more effectively and efficiently use limited resources to prevent multiple forms of violence and save lives. This article presents approaches used by 2 state health departments, the Maryland Department of Health and Mental Hygiene and the Colorado Department of Public Health and Environment, to integrate a shared risk and protective factor approach into their violence prevention work and identifies key lessons learned that may serve to inform crosscutting violence prevention efforts in other states. PMID:29189502

  10. Modeling water quality in an urban river using hydrological factors--data driven approaches.

    Science.gov (United States)

    Chang, Fi-John; Tsai, Yu-Hsuan; Chen, Pin-An; Coynel, Alexandra; Vachaud, Georges

    2015-03-15

    Contrasting seasonal variations occur in river flow and water quality as a result of short duration, severe intensity storms and typhoons in Taiwan. Sudden changes in river flow caused by impending extreme events may impose serious degradation on river water quality and fateful impacts on ecosystems. Water quality is measured in a monthly/quarterly scale, and therefore an estimation of water quality in a daily scale would be of good help for timely river pollution management. This study proposes a systematic analysis scheme (SAS) to assess the spatio-temporal interrelation of water quality in an urban river and construct water quality estimation models using two static and one dynamic artificial neural networks (ANNs) coupled with the Gamma test (GT) based on water quality, hydrological and economic data. The Dahan River basin in Taiwan is the study area. Ammonia nitrogen (NH3-N) is considered as the representative parameter, a correlative indicator in judging the contamination level over the study. Key factors the most closely related to the representative parameter (NH3-N) are extracted by the Gamma test for modeling NH3-N concentration, and as a result, four hydrological factors (discharge, days w/o discharge, water temperature and rainfall) are identified as model inputs. The modeling results demonstrate that the nonlinear autoregressive with exogenous input (NARX) network furnished with recurrent connections can accurately estimate NH3-N concentration with a very high coefficient of efficiency value (0.926) and a low RMSE value (0.386 mg/l). Besides, the NARX network can suitably catch peak values that mainly occur in dry periods (September-April in the study area), which is particularly important to water pollution treatment. The proposed SAS suggests a promising approach to reliably modeling the spatio-temporal NH3-N concentration based solely on hydrological data, without using water quality sampling data. It is worth noticing that such estimation can be

  11. Understanding key factors affecting electronic medical record implementation: a sociotechnical approach.

    Science.gov (United States)

    Cucciniello, Maria; Lapsley, Irvine; Nasi, Greta; Pagliari, Claudia

    2015-07-17

    Recent health care policies have supported the adoption of Information and Communication Technologies (ICT) but examples of failed ICT projects in this sector have highlighted the need for a greater understanding of the processes used to implement such innovations in complex organizations. This study examined the interaction of sociological and technological factors in the implementation of an Electronic Medical Record (EMR) system by a major national hospital. It aimed to obtain insights for managers planning such projects in the future and to examine the usefulness of Actor Network Theory (ANT) as a research tool in this context. Case study using documentary analysis, interviews and observations. Qualitative thematic analysis drawing on ANT. Qualitative analyses revealed a complex network of interactions between organizational stakeholders and technology that helped to shape the system and influence its acceptance and adoption. The EMR clearly emerged as a central 'actor' within this network. The results illustrate how important it is to plan innovative and complex information systems with reference to (i) the expressed needs and involvement of different actors, starting from the initial introductory phase; (ii) promoting commitment to the system and adopting a participative approach; (iii) defining and resourcing new roles within the organization capable of supporting and sustaining the change and (iv) assessing system impacts in order to mobilize the network around a common goal. The paper highlights the organizational, cultural, technological, and financial considerations that should be taken into account when planning strategies for the implementation of EMR systems in hospital settings. It also demonstrates how ANT may be usefully deployed in evaluating such projects.

  12. Factores de riesgo de preeclampsia: enfoque inmunoendocrino. Parte I Risk factors for preeclampsia: an immunoendocrine approach. Part I

    Directory of Open Access Journals (Sweden)

    Jeddú Cruz Hernández

    2007-12-01

    Full Text Available En esta primera parte se realiza una amplia revisión de los factores clásicos de riesgo de preeclampsia, enfatizando en los aspectos inmunoendocrinos en cada uno de los casos. Se propuso una clasificación que los divide en 2 grandes grupos: maternos y ambientales, y esta constituye el eje central a partir del cual se realiza la discusión de los diferentes aspectos que integran esta revisión, la cual evidencia la importancia que tienen el sistema inmunológico y el endocrino en la fisiopatología, y el surgimiento de la enfermedad hipertensiva inducida por el embarazo.In this first part, a wide review of the classical risk factors for preeclampsia was made, making emphasis on the endocrine aspects in each case. It was proposed a classification that divided them into 2 large groups: maternal and environmental. This was the central axis from which the different aspects of this review were discussed, evidencing the importance of the immunological and endocrine systems in the physiopathology, and the appearance of the hypertensive disease induced by pregnancy.

  13. Unconditionally stable perfectly matched layer boundary conditions

    NARCIS (Netherlands)

    De Raedt, H.; Michielsen, K.

    2007-01-01

    A brief review is given of a systematic, product-formula based approach to construct unconditionally stable algorithms for solving the time-dependent Maxwell equations. The fundamental difficulties that arise when we want to incorporate uniaxial perfectly matched layer boundary conditions into this

  14. Expression, Purification, and Analysis of Unknown Translation Factors from "Escherichia Coli": A Synthesis Approach

    Science.gov (United States)

    Walter, Justin D.; Littlefield, Peter; Delbecq, Scott; Prody, Gerry; Spiegel, P. Clint

    2010-01-01

    New approaches are currently being developed to expose biochemistry and molecular biology undergraduates to a more interactive learning environment. Here, we propose a unique project-based laboratory module, which incorporates exposure to biophysical chemistry approaches to address problems in protein chemistry. Each of the experiments described…

  15. Application of methodological approach to selection of sportswomen to calisthenics teams for group exercises, considering compatibility factor

    Directory of Open Access Journals (Sweden)

    O.S. Kozhanova

    2015-04-01

    Full Text Available Purpose: motivation of methodological approach to selection of sportswomen to calisthenics teams for group exercises considering compatibility factor. Material: in the research 40 high qualification sportswomen of 17-23 yrs age with sport experience of 11-16 years participated. With cluster analysis 10 gymnasts with morphological indicators, meeting modern standards of group exercises were selected. Results: we found 5 generalized factors, which characterize structure of selection to teams and determines 72% of dispersion. Influence of kinds and connected with them criteria of compatibility on efficiency of gymnasts’ competition functioning were also determined. The authors substantiated methodological approach to selection of sportswomen to calisthenics teams for group exercises, considering compatibility factor. Conclusions: in selection to calisthenics teams for group exercises it is purposeful to realize complex registration of compatibility kinds, considering gymnasts’ similar features by recommended indicators.

  16. Assessing the situational factors and impulsive buying behavior: Market segmentation approach

    OpenAIRE

    Mihić, Mirela; Kursan, Ivana

    2010-01-01

    The purpose of this study is to determine the correlation between situational factors and impulsive buying behavior with the aim of separating an adequate number of different customer segments. The study will try to provide answers to the following questions: Can situational factors stimulate impulsive purchase and to what extent? Considering the effect of the analyzed situational factors on impulsive buying is it possible to isolate different consumer segments? Do these segments differ in te...

  17. Marginally Stable Nuclear Burning

    Science.gov (United States)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  18. A Common Factors Approach to Supporting University Students Experiencing Psychological Distress

    Science.gov (United States)

    Surette, Tanya E.; Shier, Micheal L.

    2017-01-01

    This study empirically assessed the applicability of the common factors model to students accessing university-based counseling (n = 102). Participants rated symptoms of depression, anxiety, and somatization at intake and discharge. Therapists kept detailed session notes on client factors and therapy process variables. Data were analyzed utilizing…

  19. WISC-IV and Clinical Validation of the Four- and Five-Factor Interpretative Approaches

    Science.gov (United States)

    Weiss, Lawrence G.; Keith, Timothy Z.; Zhu, Jianjun; Chen, Hsinyi

    2013-01-01

    The purpose of this study was to determine the constructs measured by the WISC-IV and the consistency of measurement across large normative and clinical samples. Competing higher order four- and five-factor models were analyzed using the WISC-IV normative sample and clinical subjects. The four-factor solution is the model published with the test…

  20. Novel Perturbation Approach for the Structure Factor of the Attractive Hard-Core Yukawa Fluid.

    Czech Academy of Sciences Publication Activity Database

    Melnyk, R.; Moučka, F.; Nezbeda, Ivo; Trokhymchuk, A.

    2007-01-01

    Roč. 127, 9 (2007) , s. 094510-094517 ISSN 0021-9606 R&D Projects: GA AV ČR(CZ) IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : equilibrium statistic al mechanics * statistic structure factor * phase-diagrams Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.044, year: 2007

  1. Regional determinants of FDI in China: a factor-based approach

    NARCIS (Netherlands)

    Martijn A. Boermans; Zhang Yi; Hein Roelfsema

    2011-01-01

    We empirically investigate the factors that drive the uneven regional distribution of foreign direct investment (FDI) across Chinese provinces from 1995 to 2006. We first perform a factor analysis to summarize information embodied in around 40 variables and derive four FDI determinants:

  2. A Market Segmentation Approach for Higher Education Based on Rational and Emotional Factors

    Science.gov (United States)

    Angulo, Fernando; Pergelova, Albena; Rialp, Josep

    2010-01-01

    Market segmentation is an important topic for higher education administrators and researchers. For segmenting the higher education market, we have to understand what factors are important for high school students in selecting a university. Extant literature has probed the importance of rational factors such as teaching staff, campus facilities,…

  3. Factors Affecting Perceived Learning, Satisfaction, and Quality in the Online MBA: A Structural Equation Modeling Approach

    Science.gov (United States)

    Sebastianelli, Rose; Swift, Caroline; Tamimi, Nabil

    2015-01-01

    The authors examined how six factors related to content and interaction affect students' perceptions of learning, satisfaction, and quality in online master of business administration (MBA) courses. They developed three scale items to measure each factor. Using survey data from MBA students at a private university, the authors estimated structural…

  4. Evaluating Effective Teaching in College Level Economics Using Student Ratings of Instruction: A Factor Analytic Approach

    Science.gov (United States)

    Agbetsiafa, Douglas

    2010-01-01

    This paper explores the factors that affect students' evaluation of economic instruction using a sample of 1300 completed rating instruments at a comprehensive four-year mid-western public university. The study uses factor analysis to determine the validity and reliability of the evaluation instrument in assessing instructor or course…

  5. Modelling stable water isotopes: Status and perspectives

    Directory of Open Access Journals (Sweden)

    Werner M.

    2010-12-01

    Full Text Available Modelling of stable water isotopes H2 18O and HDO within various parts of the Earth’s hydrological cycle has clearly improved our understanding of the interplay between climatic variations and related isotope fractionation processes. In this article key principles and major research results of stable water isotope modelling studies are described. Emphasis is put on research work using explicit isotope diagnostics within general circulation models as this highly complex model setup bears many resemblances with studies using simpler isotope modelling approaches.

  6. Factors Associated With Presenteeism and Psychological Distress Using a Theory-Driven Approach.

    Science.gov (United States)

    Coutu, Marie-France; Corbière, Marc; Durand, Marie-José; Nastasia, Iuliana; Labrecque, Marie-Elise; Berbiche, Djamal; Albert, Valérie

    2015-06-01

    To test a model of presenteeism on the basis of established and emerging theories separated into organizational and individual factors that could be mediated by psychological distress. This was a Web survey of 2371 employees (response rate of 48%) of a provincial government agency. We assessed theories with validated measures for organizational and individual factors. Psychological distress was negatively associated to presenteeism, when controlling for sex, short-term work absence in the last year, and social desirability. Both individual and organizational factors were related to psychological distress. The most important factors included the presence of stress events in the preceding 6 months, extrinsic efforts (interruptions, work requirements), self-esteem as a worker, and internal amotivation. By identifying modifiable factors, our results suggest that the implementation of a work organization structure that promotes stimulation and accomplishment would reduce psychological distress and further presenteeism.

  7. Teaching How to Program With a Playful Approach : A Review of Success Factors

    OpenAIRE

    Robert Heininger, Loina Prifti, Victor Seifert, Matthias Utesch, Helmut Krcmar

    2017-01-01

    Programming has become a vital skill in today’s society and economy. Therefore, it is important to teach programming in early stages of the education. Since learning how to program differs from other, more traditional courses in schools, an application oriented approach to teaching and learning is required. The playful approach, as a part of self-regulated personalized learning strategies, offers the possibility to engage students, and teach students how to program hands-on. In this paper, we...

  8. The effects of predictor method factors on selection outcomes : a modular approach to personnel selection procedures

    OpenAIRE

    Lievens, Filip; Sackett, Paul R.

    2017-01-01

    Past reviews and meta-analyses typically conceptualized and examined selection procedures as holistic entities. We draw on the product design literature to propose a modular approach as a complementary perspective to conceptualizing selection procedures. A modular approach means that a product is broken down into its key underlying components. Therefore, we start by presenting a modular framework that identifies the important measurement components of selection procedures. Next, we adopt this...

  9. Assessing the Structure of the Ways of Coping Questionnaire in Fibromyalgia Patients Using Common Factor Analytic Approaches.

    Science.gov (United States)

    Van Liew, Charles; Santoro, Maya S; Edwards, Larissa; Kang, Jeremy; Cronan, Terry A

    2016-01-01

    The Ways of Coping Questionnaire (WCQ) is a widely used measure of coping processes. Despite its use in a variety of populations, there has been concern about the stability and structure of the WCQ across different populations. This study examines the factor structure of the WCQ in a large sample of individuals diagnosed with fibromyalgia. The participants were 501 adults (478 women) who were part of a larger intervention study. Participants completed the WCQ at their 6-month assessment. Foundational factoring approaches were performed on the data (i.e., maximum likelihood factoring [MLF], iterative principal factoring [IPF], principal axis factoring (PAF), and principal components factoring [PCF]) with oblique oblimin rotation. Various criteria were evaluated to determine the number of factors to be extracted, including Kaiser's rule, Scree plot visual analysis, 5 and 10% unique variance explained, 70 and 80% communal variance explained, and Horn's parallel analysis (PA). It was concluded that the 4-factor PAF solution was the preferable solution, based on PA extraction and the fact that this solution minimizes nonvocality and multivocality. The present study highlights the need for more research focused on defining the limits of the WCQ and the degree to which population-specific and context-specific subscale adjustments are needed.

  10. Proposal of a risk-factor-based analytical approach for integrating occupational health and safety into project risk evaluation.

    Science.gov (United States)

    Badri, Adel; Nadeau, Sylvie; Gbodossou, André

    2012-09-01

    Excluding occupational health and safety (OHS) from project management is no longer acceptable. Numerous industrial accidents have exposed the ineffectiveness of conventional risk evaluation methods as well as negligence of risk factors having major impact on the health and safety of workers and nearby residents. Lack of reliable and complete evaluations from the beginning of a project generates bad decisions that could end up threatening the very existence of an organization. This article supports a systematic approach to the evaluation of OHS risks and proposes a new procedure based on the number of risk factors identified and their relative significance. A new concept called risk factor concentration along with weighting of risk factor categories as contributors to undesirable events are used in the analytical hierarchy process multi-criteria comparison model with Expert Choice(©) software. A case study is used to illustrate the various steps of the risk evaluation approach and the quick and simple integration of OHS at an early stage of a project. The approach allows continual reassessment of criteria over the course of the project or when new data are acquired. It was thus possible to differentiate the OHS risks from the risk of drop in quality in the case of the factory expansion project. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Optimization of healthcare supply chain in context of macro-ergonomics factors by a unique mathematical programming approach.

    Science.gov (United States)

    Azadeh, A; Motevali Haghighi, S; Gaeini, Z; Shabanpour, N

    2016-07-01

    This study presents an integrated approach for analyzing the impact of macro-ergonomics factors in healthcare supply chain (HCSC) by data envelopment analysis (DEA). The case of this study is the supply chain (SC) of a real hospital. Thus, healthcare standards and macro-ergonomics factors are considered to be modeled by the mathematical programming approach. Over 28 subsidiary SC divisions with parallel missions and objectives are evaluated by analyzing inputs and outputs through DEA. Each division in this HCSC is considered as decision making unit (DMU). This approach can analyze the impact of macro-ergonomics factors on supply chain management (SCM) in healthcare sector. Also, this method ranks the relevant performance efficiencies of each HCSC. In this study by using proposed method, the most effective macro-ergonomics factor on HCSC is identified as "teamwork" issue. Also, this study would help managers to identify the areas of weaknesses in their SCM system and set improvement target plan for the related SCM system in healthcare industry. To the best of our knowledge, this is the first study for macro-ergonomics optimization of HCSC. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  12. Women-specific risk factors for heart failure: A genetic approach.

    Science.gov (United States)

    van der Kemp, Jet; van der Schouw, Yvonne T; Asselbergs, Folkert W; Onland-Moret, N Charlotte

    2018-03-01

    Heart failure is a complex disease, which is presented differently by men and women. Several studies have shown that reproductive factors, such as age at natural menopause, parity and polycystic ovarian syndrome (PCOS), may play a role in the development of heart failure. Shared genetics may provide clues to underlying mechanisms; however, this has never been examined. Therefore, the aim of the current study was to explore whether any reproductive factor is potentially related to heart failure in women, based on genetic similarities. Conducting a systematic literature review, single nucleotide polymorphisms (SNPs) associated with reproductive factors, heart failure and its risk factors were extracted from recent genome-wide association studies. We tested whether there was any overlap between the SNPs and their proxies of reproductive risk factors with those known for heart failure or its risk factors. In total, 520 genetic variants were found that are associated with reproductive factors, namely age at menarche, age at natural menopause, menstrual cycle length, PCOS, preeclampsia, preterm delivery and spontaneous dizygotic twinning. For heart failure and associated phenotypes, 25 variants were found. Genetic variants for reproductive factors did not overlap with those for heart failure. However, age at menarche, gestational diabetes and PCOS were found to be genetically linked to risk factors for heart failure, such as atrial fibrillation, diabetes and smoking. Corresponding implicated genes, such as TNNI3K, ErbB3, MKL2, MTNR1B and PRKD1, may explain the associations between reproductive factors and heart failure. Exact effector mechanisms of these genes remain to be investigated further. Copyright © 2017. Published by Elsevier B.V.

  13. Problematic eating behaviors among bariatric surgical candidates: a psychometric investigation and factor analytic approach.

    Science.gov (United States)

    Gelinas, Bethany L; Delparte, Chelsea A; Wright, Kristi D; Hart, Regan

    2015-01-01

    Psychological factors (e.g., anxiety, depression) are routinely assessed in bariatric pre-surgical programs, as high levels of psychopathology are consistently related to poor program outcomes (e.g., failure to lose significant weight pre-surgery, weight regain post-surgery). Behavioral factors related to poor program outcomes and ways in which behavioral and psychological factors interact, have received little attention in bariatric research and practice. Potentially problematic behavioral factors are queried by Section H of the Weight and Lifestyle Inventory (WALI-H), in which respondents indicate the relevance of certain eating behaviors to obesity. A factor analytic investigation of the WALI-H serves to improve the way in which this assessment tool is interpreted and used among bariatric surgical candidates, and subsequent moderation analyses serve to demonstrate potential compounding influences of psychopathology on eating behavior factors. Bariatric surgical candidates (n =362) completed several measures of psychopathology and the WALI-H. Item responses from the WALI-H were subjected to principal axis factoring with oblique rotation. Results revealed a three-factor model including: (1) eating in response to negative affect, (2) overeating/desirability of food, and (3) eating in response to positive affect/social cues. All three behavioral factors of the WALI-H were significantly associated with measures of depression and anxiety. Moderation analyses revealed that depression did not moderate the relationship between anxiety and any eating behavior factor. Although single forms of psychopathology are related to eating behaviors, the combination of psychopathology does not appear to influence these problematic behaviors. Recommendations for pre-surgical assessment and treatment of bariatric surgical candidates are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Official loyalty as the factor of official activity: administratively-legal and phenomenological approaches

    Directory of Open Access Journals (Sweden)

    Gornostaev S.V.

    2017-04-01

    Full Text Available The article discusses the administrative-legal and phenomenological approaches to understanding the official loyalty. Official loyalty is being considered under the administrative-legal approach as adherence to formal official duty, which is a system of obligations, taken together with official status, the source of which are: normative base of service activity, legal requirements of the head and public interests. Lists of the limitations of administrative-legal approach to understanding the of official loyalty: weak underdeveloped concept, the failure to take into account the wide range of situations, operation with a models rather than actual processes. Discusses the advantages of the phenomenological approach in studying the performance of loyalty: its psychological advantages, the existence of a theoretical framework, the work with the real phenomena. Within the phenomenological approach official loyalty is defined as psychological-behavioral integration of the employee in the group operating in the service sector, on the basis of a common cause of activities. Possibilities of sharing of the considered approaches for the decision of problems of optimization of official activity are designated.

  15. The Factors Influencing Satisfaction with Public City Transport: A Structural Equation Modelling Approach

    Directory of Open Access Journals (Sweden)

    Pawlasova Pavlina

    2015-12-01

    Full Text Available Satisfaction is one of the key factors which influences customer loyalty. We assume that the satisfied customer will be willing to use the ssame service provider again. The overall passengers´ satisfaction with public city transport may be affected by the overall service quality. Frequency, punctuality, cleanliness in the vehicle, proximity, speed, fare, accessibility and safety of transport, information and other factors can influence passengers´ satisfaction. The aim of this paper is to quantify factors and identify the most important factors influencing customer satisfaction with public city transport within conditions of the Czech Republic. Two methods of analysis are applied in order to fulfil the aim. The method of factor analysis and the method Varimax were used in order to categorize variables according to their mutual relations. The method of structural equation modelling was used to evaluate the factors and validate the model. Then, the optimal model was found. The logistic parameters, including service continuity and frequency, and service, including information rate, station proximity and vehicle cleanliness, are the factors influencing passengers´ satisfaction on a large scale.

  16. Bottom-up approaches for preparing drug nanocrystals: formulations and factors affecting particle size.

    Science.gov (United States)

    Sinha, Biswadip; Müller, Rainer H; Möschwitzer, Jan P

    2013-08-30

    The solubility dependent bioavailability problem has become a major hurdle in drug development processes. Drug nanocrystals have been widely accepted by the pharmaceutical industry to improve the bioavailability of poorly water-soluble compounds. Top-down and bottom-up technologies are the two primary technical approaches of drug nanocrystal production. Though the top-down approach has been hugely successful on the commercial front, it has some inherent drawbacks that necessitate the emergence of alternate approaches. The bottom-up approach has not yet been established as a successful commercial technology. However, it has the potential to produce small size drug nanocrystals with less energy demanding processes. The bottom-up approach is commonly known as precipitation technique. It would be possible to stabilize particles at an early stage of precipitation and to generate drug nanocrystals. In the first part of this review article, we have discussed various bottom-up technologies that are currently in use. This has been followed by description and analysis of various process parameters that can affect the final particle size of the drug nanocrystals. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Factors Influencing Implementation of OHSAS 18001 in Indian Construction Organizations: Interpretive Structural Modeling Approach

    Directory of Open Access Journals (Sweden)

    Sunku Venkata Siva Rajaprasad

    2015-09-01

    Conclusion: Management commitment has the maximum driving power and the most influential factor is safety policy, which states clearly the commitment of top management towards occupational safety and health.

  18. The Forecasting Power of the Yield Curve, a Supervised Factor Model Approach

    DEFF Research Database (Denmark)

    Boldrini, Lorenzo; Hillebrand, Eric Tobias

    We study the forecast power of the yield curve for macroeconomic time series, such as consumer price index, personal consumption expenditures, producer price index, real disposable income, unemployment rate, and industrial production. We employ a state-space model in which the forecasting objective...... is included in the state vector. This amounts to an augmented dynamic factor model in which the factors (level, slope, and curvature of the yield curve) are supervised for the macroeconomic forecast target. In other words, the factors are informed about the dynamics of the forecast objective. The factor...... loadings have the Nelson and Siegel (1987) structure and we consider one forecast target at a time. We compare the forecasting performance of our specification to benchmark models such as principal components regression, partial least squares, and ARMA(p,q) processes. We use the yield curve data from G...

  19. The Factors Influencing Satisfaction with Public City Transport: A Structural Equation Modelling Approach

    OpenAIRE

    Pawlasova Pavlina

    2015-01-01

    Satisfaction is one of the key factors which influences customer loyalty. We assume that the satisfied customer will be willing to use the ssame service provider again. The overall passengers´ satisfaction with public city transport may be affected by the overall service quality. Frequency, punctuality, cleanliness in the vehicle, proximity, speed, fare, accessibility and safety of transport, information and other factors can influence passengers´ satisfaction. The aim of this pap...

  20. Velocity, attenuation, and quality factor in anisotropic viscoelastic media: A perturbation approach

    Czech Academy of Sciences Publication Activity Database

    Vavryčuk, Václav

    2008-01-01

    Roč. 73, č. 5 (2008), D63-D73 ISSN 0016-8033 R&D Projects: GA ČR GA205/05/2182; GA AV ČR IAA300120801 Grant - others:EC(XE) MTKI-CT-2004-517242 Institutional research plan: CEZ:AV0Z30120515 Keywords : wave propagation * anisotropic viscoelastic media * Q-factor Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.349, year: 2008

  1. Determinants of job stress in chemical process industry: A factor analysis approach.

    Science.gov (United States)

    Menon, Balagopal G; Praveensal, C J; Madhu, G

    2015-01-01

    Job stress is one of the active research domains in industrial safety research. The job stress can result in accidents and health related issues in workers in chemical process industries. Hence it is important to measure the level of job stress in workers so as to mitigate the same to avoid the worker's safety related problems in the industries. The objective of this study is to determine the job stress factors in the chemical process industry in Kerala state, India. This study also aims to propose a comprehensive model and an instrument framework for measuring job stress levels in the chemical process industries in Kerala, India. The data is collected through a questionnaire survey conducted in chemical process industries in Kerala. The collected data out of 1197 surveys is subjected to principal component and confirmatory factor analysis to develop the job stress factor structure. The factor analysis revealed 8 factors that influence the job stress in process industries. It is also found that the job stress in employees is most influenced by role ambiguity and the least by work environment. The study has developed an instrument framework towards measuring job stress utilizing exploratory factor analysis and structural equation modeling.

  2. Factor analyses of the Hospital Anxiety and Depression Scale: a Bayesian structural equation modeling approach.

    Science.gov (United States)

    Fong, Ted Chun Tat; Ho, Rainbow Tin Hung

    2013-12-01

    The latent structure of the Hospital Anxiety and Depression Scale (HADS) has caused inconsistent results in the literature. The HADS is frequently analyzed via maximum likelihood confirmatory factor analysis (ML-CFA). However, the overly restrictive assumption of exact zero cross-loadings and residual correlations in ML-CFA can lead to poor model fits and distorted factor structures. This study applied Bayesian structural equation modeling (BSEM) to evaluate the latent structure of the HADS. Three a priori models, the two-factor, three-factor, and bifactor models, were investigated in a Chinese community sample (N = 312) and clinical sample (N = 198) using ML-CFA and BSEM. BSEM specified approximate zero cross-loadings and residual correlations through the use of zero-mean, small-variance informative priors. The model comparison was based on the Bayesian information criterion (BIC). Using ML-CFA, none of the three models provided an adequate fit for either sample. The BSEM two-factor model with approximate zero cross-loadings and residual correlations fitted both samples well with the lowest BIC of the three models and displayed a simple and parsimonious factor-loading pattern. The study demonstrated that the two-factor structure fitted the HADS well, suggesting its usefulness in assessing the symptoms of anxiety and depression in clinical practice. BSEM is a sophisticated and flexible statistical technique that better reflects substantive theories and locates the source of model misfit. Future use of BSEM is recommended to evaluate the latent structure of other psychological instruments.

  3. Interrelationships of Physical Activity and Sleep with Cardiovascular Risk Factors: a Person-Oriented Approach.

    Science.gov (United States)

    Wennman, Heini; Kronholm, Erkki; Partonen, Timo; Tolvanen, Asko; Peltonen, Markku; Vasankari, Tommi; Borodulin, Katja

    2015-12-01

    Associations of behaviorally modifiable factors like physical activity (PA), sedentary behaviors, and sleep with cardiovascular diseases (CVDs) are complicated. We examined whether membership in latent classes (LCs) differentiated by PA and sleep profiles (real-life clustering of behaviors in population subgroups) associate with metabolic risk factors and CVD risk. The National FINRISK 2012 Study comprise a cross-sectional sample of 10,000 Finns aged 25 to 74 years. Analyses included participants with complete data on a health questionnaire, a health examination, who had no prevalent CVD (n = 4031). LCs with PA and sleep profiles were previously defined using latent class analysis. Ten metabolic risk factors and the Framingham 10-year CVD risk score were compared between the LCs. PA and sleep class profiles were substantially similar for genders. Compared to LC-1, with a profile including high PA and sufficient sleep, membership in LC-4, with a profile including sedentariness and insufficient sleep was associated with high metabolic risk factors in women but not in men. In women, also membership in LC-2, with a profile including light PA, sufficient sleep, and high sedentariness was associated with high metabolic risk factors. The Framingham 10-year CVD risk score was highest in LCs 2 and 4 in both genders. Membership in LCs differentiated by PA and sleep profiles was associated with metabolic risk factors merely in women, suggesting gender differences in the interrelationships of health behaviors and metabolic risk factors. Total CVD risk differed between the LCs despite of gender; however, the effect was small.

  4. Profile-Likelihood Approach for Estimating Generalized Linear Mixed Models with Factor Structures

    Science.gov (United States)

    Jeon, Minjeong; Rabe-Hesketh, Sophia

    2012-01-01

    In this article, the authors suggest a profile-likelihood approach for estimating complex models by maximum likelihood (ML) using standard software and minimal programming. The method works whenever setting some of the parameters of the model to known constants turns the model into a standard model. An important class of models that can be…

  5. Influencing factors for condition-based maintenance in railway tracks using knowledge-based approach

    NARCIS (Netherlands)

    Jamshidi, A.; Hajizadeh, S.; Naeimi, M.; Nunez Vicencio, Alfredo; Li, Z.

    2017-01-01

    In this paper, we present a condition-based maintenance decision method using
    knowledge-based approach for rail surface defects. A railway track may contain a considerable number of surface defects which influence track maintenance decisions. The proposed method is based on two sets of

  6. Cross-Cultural Validation of Models of Approaches to Learning: An Application of Confirmatory Factor Analysis.

    Science.gov (United States)

    Wong, Ngai-Ying; Lin, Wen-Ying; Watkins, David

    1996-01-01

    Analyzes responses to a questionnaire from 10 samples of primary and secondary school students from Nigeria, Zimbabwe, Malaysia, Beijing, Hong Kong, and Canada. The questionnaire covered learning strategies, approaches, and motivation. These data were then analyzed using six different structural equation models. Includes discussion of the models…

  7. Detecting and correcting the bias of unmeasured factors using perturbation analysis: a data-mining approach

    Science.gov (United States)

    2014-01-01

    Background The randomized controlled study is the gold-standard research method in biomedicine. In contrast, the validity of a (nonrandomized) observational study is often questioned because of unknown/unmeasured factors, which may have confounding and/or effect-modifying potential. Methods In this paper, the author proposes a perturbation test to detect the bias of unmeasured factors and a perturbation adjustment to correct for such bias. The proposed method circumvents the problem of measuring unknowns by collecting the perturbations of unmeasured factors instead. Specifically, a perturbation is a variable that is readily available (or can be measured easily) and is potentially associated, though perhaps only very weakly, with unmeasured factors. The author conducted extensive computer simulations to provide a proof of concept. Results Computer simulations show that, as the number of perturbation variables increases from data mining, the power of the perturbation test increased progressively, up to nearly 100%. In addition, after the perturbation adjustment, the bias decreased progressively, down to nearly 0%. Conclusions The data-mining perturbation analysis described here is recommended for use in detecting and correcting the bias of unmeasured factors in observational studies. PMID:24499374

  8. The human factors engineering approach to biomedical informatics projects: state of the art, results, benefits and challenges.

    Science.gov (United States)

    Beuscart-Zéphir, M-C; Elkin, Peter; Pelayo, Sylvia; Beuscart, Regis

    2007-01-01

    The objective of this paper is to define a comprehensible overview of the Human Factors approach to biomedical informatics applications for healthcare. The overview starts with a presentation of the necessity of a proper management of Human factors for Healthcare IT projects to avoid unusable products and unsafe work situations. The first section is dedicated to definitions of the Human Factors Engineering (HFE) main concepts. The second section describes a functional model of an HFE lifecycle adapted for healthcare work situations. The third section provides an overview of existing HF and usability methods for healthcare products and presents a selection of interesting results. The last section discusses the benefits and limitations of the HFE approach. Literature review based on Pubmed and conference proceedings in the field of Medical Informatics coupled with a review of other databases and conference proceedings in the field of Ergonomics focused on papers addressing healthcare work and system design. Usability studies performed on healthcare applications have uncovered unacceptable usability flaws that make the systems error prone, thus endangering the patient safety. Moreover, in many cases, the procurement and the implementation process simply forget about human factors: following only technological considerations, they issue potentially dangerous and always unpleasant work situations. But when properly applied to IT projects, the HFE approach proves efficient when seeking to improve patient safety, users' satisfaction and adoption of the products. We recommend that the HFE methodology should be applied to most informatics and systems development projects, and the usability of the products should be systematically checked before permitting their release and implementation. This requires the development of Centers specialized in Human Factors for Healthcare and Patient safety in each Country/Region.

  9. An Auditing Approach for ERP Systems Examining Human Factors that Influence ERP User Satisfaction

    Directory of Open Access Journals (Sweden)

    Theodoros MITAKOS

    2010-01-01

    Full Text Available This paper tries to connect the successful implementation and operation of the ERP (Enterprise Resource Planning information systems with people and their characteristics through a pilot survey. It examines the human factors that influence ERP user satisfaction. The presented survey tests 14 hypotheses and is based on the model developed by Zviran, Pliskin & Levin [21]. An additional factor has been added to the specified model, the self-efficacy factor analyzed by Bandura [1]. The results are based on 250 ERP users that responded to the survey. The key findings that were revealed by data analysis were that none of the human socio-demographic characteristics do influence ERP user satisfaction. Additionally it was found that perceived usefulness and self-efficacy are the key directors of the ERP user satisfaction. Moreover suggestions are given about how the companies should handle ERP usage in order to develop the prerequisites for increasing user satisfaction and productivity accordingly.

  10. Approaches for the integration of human factors into the upgrading and refurbishment of control rooms - Summary and conclusions - Principal Working Group 1 on Operating Experience and Human Factors

    International Nuclear Information System (INIS)

    2002-01-01

    A modern approach to control room design, be it for upgrading or complete refurbishment, requires the integration of many disciplines and approaches. The integration of human factors into such a process continues to present challenges. How such a process should be conceived, planned, and carried out is of considerable interest to designers, operators and regulators. Many NPPs around the world have been, or will be faced with decisions concerning modernization of their control rooms. Such changes can be driven by a range of issues including; the need to replace outdated control and instrumentation systems; increasing regulatory concern about human performance; or the need to provide a better process control environment for NPPs whose life cycles extend beyond that originally intended. Considering the importance of operator performance for safe and profitable operations, a process for ensuring that human factors issues are properly addressed could be central to the success or failure of such a project. Human factors is of particular importance when a combination of existing and new systems are to be used, resulting in a so-called 'hybrid' control room. The workshop addressed this topical area by providing a forum where a number of important areas could be discussed and experiences and lessons shared. Topics identified before hand as important and worthy of discussion included: - Exploration of how human factors issues can be identified. - Consideration of those processes and techniques necessary to ensure that appropriate requirements are specified, and that suitable data is gathered and analysed. - Identification and discussion of issues related to the above topics together with lessons from utilities, vendors and regulators which have faced, or are currently facing, these challenges. The meeting itself focused on the state of knowledge and current best practices within these areas and provided a forum for the open discussion of the human factors issues, as seen by

  11. Wrong-way driving crashes: A multiple correspondence approach to identify contributing factors.

    Science.gov (United States)

    Jalayer, Mohammad; Pour-Rouholamin, Mahdi; Zhou, Huaguo

    2018-01-02

    Wrong-way driving (WWD) crashes result in 1.34 fatalities per fatal crash, whereas for other non-WWD fatal crashes this number drops to 1.10. As such, further in-depth investigation of WWD crashes is necessary. The objective of this study is 2-fold: to identify the characteristics that best describe WWD crashes and to verify the factors associated with WWD occurrence. We collected and analyzed 15 years of crash data from the states of Illinois and Alabama. The final data set includes 398 WWD crashes. The rarity of WWD events and the consequently small sample size of the crash database significantly influence the application of conventional log-linear models in analyzing the data, because they use maximum-likelihood estimation. To overcome this issue, in this study, we employ multiple correspondence analysis (MCA) to define the structure of the crash data set and identify the significant contributing factors to WWD crashes on freeways. The results of the present study specify various factors that characterize and influence the probability of WWD crashes and can thus lead to the development of several safety countermeasures and recommendations. According to the obtained results, factors such as driver age, driver condition, roadway surface conditions, and lighting conditions were among the most significant contributors to WWD crashes. Despite many other methods that identify only the contributing factors, this method can identify possible associations between various contributing factors. This is an inherent advantage of the MCA method, which can provide a major opportunity for state departments of transportation (DOTs) to select safety countermeasures that are associated with multiple safety benefits.

  12. Evaluation of the Menopause-Specific Quality of Life Questionnaire: a factor-analytic approach.

    Science.gov (United States)

    Van Dole, Kristen B; DeVellis, Robert F; Brown, Rebekkah D; Funk, Michele L Jonsson; Gaynes, Bradley N; Williams, Rachel E

    2012-02-01

    Despite being used in multiple studies, the Menopause-Specific Quality of Life Questionnaire (MENQOL) has not been assessed with factor analysis, a common method of item reduction in quality of life tools. The Menopause Epidemiology Study is a cross-sectional population-based study of women 40 to 65 years old in the United States chosen from a source population selected by random digit dialing and probability sampling. We focused on 2,703 postmenopausal women for our analyses. Before analysis and to prevent model overfitting, we split our sample into two equal groups using a uniform random sample. Using parallel analysis for factor extraction, we performed confirmatory factor analysis on the MENQOL to examine the current factor structure and to evaluate the efficiency of the items in the existing tool. Reliability coefficients (Cronbach α) were calculated for each of the domains. With few exceptions, the items from the original MENQOL factored into the domains under which they were originally placed. Using this method, five items did not add significant statistical value to the scoring of the domains: difficulty sleeping; poor memory; accomplishing less than I used to; changes in appearance, texture, or tone of my skin; and feeling tired. Reliability coefficients for the four original domains were acceptable: vasomotor, 0.87; psychosocial, 0.85; physical, 0.88; and sexual, 0.77. Results from factor analysis indicate that although the MENQOL was developed more than 15 years ago, the strength of the items is still highly valuable today in the assessment of women's menopause-related quality of life.

  13. Electrically Small Magnetic Dipole Antennas With Quality Factors Approaching the Chu Lower Bound

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav; Yaghjian, Arthur D.

    2010-01-01

    that serves to reduce the internal stored energy. Closed-form expressions for the internal and external stored energies as well as for the quality factor Q are derived. The influence of the sphere radius and the material permeability and permittivity on the quality factor Q is determined and verified...... numerically. It is found that for a given antenna size and permittivity there is an optimum permeability that ensures the lowest possible Q, and this optimum permeability is inversely proportional to the square of the antenna electrical radius. When the relative permittivity is equal to 1, the optimum...

  14. Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

    International Nuclear Information System (INIS)

    Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J.

    2014-01-01

    Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation

  15. Factors Affecting Stock Returns of Firms Quoted in ISE Market: A Dynamic Panel Data Approach

    Directory of Open Access Journals (Sweden)

    Şebnem Er

    2013-07-01

    Full Text Available Several studies, explaining the factors affecting stock returns, have been published both in developed and developing countries. In many of these papers, either cross-sectional or time series methods have been applied. In this study, Dynamic Panel Data Analysis Methods have been conducted to explain the factors affecting stock returns of 64 manufacturing firms that are continuously quoted in ISE during the period of 2003-2007. The results indicate that stock performance, financial structure, activity and profitability ratios can be used to explain the stock returns as well as the oil prices, economic growth, exchange rate, interest rate, and money supply.

  16. Predicting transcription factor activities from combined analysis of microarray and ChIP data: a partial least squares approach

    Directory of Open Access Journals (Sweden)

    Strimmer Korbinian

    2005-06-01

    Full Text Available Abstract Background The study of the network between transcription factors and their targets is important for understanding the complex regulatory mechanisms in a cell. Unfortunately, with standard microarray experiments it is not possible to measure the transcription factor activities (TFAs directly, as their own transcription levels are subject to post-translational modifications. Results Here we propose a statistical approach based on partial least squares (PLS regression to infer the true TFAs from a combination of mRNA expression and DNA-protein binding measurements. This method is also statistically sound for small samples and allows the detection of functional interactions among the transcription factors via the notion of "meta"-transcription factors. In addition, it enables false positives to be identified in ChIP data and activation and suppression activities to be distinguished. Conclusion The proposed method performs very well both for simulated data and for real expression and ChIP data from yeast and E. Coli experiments. It overcomes the limitations of previously used approaches to estimating TFAs. The estimated profiles may also serve as input for further studies, such as tests of periodicity or differential regulation. An R package "plsgenomics" implementing the proposed methods is available for download from the CRAN archive.

  17. Healthcare-associated ventriculitis and meningitis in a neuro-ICU: Incidence and risk factors selected by machine learning approach.

    Science.gov (United States)

    Savin, Ivan; Ershova, Ksenia; Kurdyumova, Nataliya; Ershova, Olga; Khomenko, Oleg; Danilov, Gleb; Shifrin, Michael; Zelman, Vladimir

    2018-02-05

    To define the incidence of healthcare-associated ventriculitis and meningitis (HAVM) in the neuro-ICU and to identify HAVM risk factors using tree-based machine learning (ML) algorithms. An observational cohort study was conducted in Russia from 2010 to 2017, and included high-risk neuro-ICU patients. We utilized relative risk analysis, regressions, and ML to identify factors associated with HAVM development. 2286 patients of all ages were included, 216 of them had HAVM. The cumulative incidence of HAVM was 9.45% [95% CI 8.25-10.65]. The incidence of EVD-associated HAVM was 17.2 per 1000 EVD-days or 4.3% [95% CI 3.47-5.13] per 100 patients. Combining all three methods, we selected four important factors contributing to HAVM development: EVD, craniotomy, superficial surgical site infections after neurosurgery, and CSF leakage. The ML models performed better than regressions. We first reported HAVM incidence in a neuro-ICU in Russia. We showed that tree-based ML is an effective approach to study risk factors because it enables the identification of nonlinear interaction across factors. We suggest that the number of found risk factors and the duration of their presence in patients should be reduced to prevent HAVM. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. The Relationships between Polymorphisms in Genes Encoding the Growth Factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A and the Restenosis Process in Patients with Stable Coronary Artery Disease Treated with Bare Metal Stent.

    Directory of Open Access Journals (Sweden)

    Tadeusz Osadnik

    Full Text Available Neointima forming after stent implantation consists of vascular smooth muscle cells (VSMCs in 90%. Growth factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A play an important role in VSMC proliferation and migration to the tunica intima after arterial wall injury. The aim of this paper was an analysis of functional polymorphisms in genes encoding TGF-β1, PDGFB, EGF, bFGF and VEGF-A in relation to in-stent restenosis (ISR.265 patients with a stable coronary artery disease (SCAD hospitalized in our center in the years 2007-2011 were included in the study. All patients underwent stent implantation at admission to the hospital and had another coronary angiography performed due to recurrence of the ailments or a positive result of the test assessing the coronary flow reserve. Angiographically significant ISR was defined as stenosis >50% in the stented coronary artery segment. The patients were divided into two groups-with angiographically significant ISR (n = 53 and without significant ISR (n = 212. Additionally, the assessment of late lumen loss (LLL in vessel was performed. EGF rs4444903 polymorphism was genotyped using the PCR-RFLP method whilst rs1800470 (TGFB1, rs2285094 (PDGFB rs308395 (bFGF and rs699947 (VEGF-A were determined using the TaqMan method.Angiographically significant ISR was significantly less frequently observed in the group of patients with the A/A genotype of rs1800470 polymorphism (TGFB1 versus patients with A/G and G/G genotypes. In the multivariable analysis, LLL was significantly lower in patients with the A/A genotype of rs1800470 (TGFB1 versus those with the A/G and G/G genotypes and higher in patients with the A/A genotype of the VEGF-A polymorphism versus the A/C and C/C genotypes. The C/C genotype of rs2285094 (PDGFB was associated with greater LLL compared to C/T heterozygotes and T/T homozygotes.The polymorphisms rs1800470, rs2285094 and rs6999447 of the TGFB1, PDGFB and VEGF-A genes, respectively, are associated with LLL

  19. Nursing students' attitudes towards information and communication technology: an exploratory and confirmatory factor analytic approach.

    Science.gov (United States)

    Lee, Jung Jae; Clarke, Charlotte L

    2015-05-01

    The aim of this study was to develop and psychometrically test a shortened version of the Information Technology Attitude Scales for Health, in the investigation of nursing students with clinical placement experiences. Nurses and nursing students need to develop high levels of competency in information and communication technology. However, they encounter statistically significant barriers in the use of the technology. Although some instruments have been developed to measure factors that influence nurses' attitudes towards technology, the validity is questionable and few studies have been developed to test the attitudes of nursing students, in particular. A cross-sectional survey design was performed. The Information Technology Attitude Scales for Health was used to collect data from October 2012-December 2012. A panel of experts reviewed the content of the instrument and a pilot study was conducted. Following this, a total of 508 nursing students, who were engaged in clinical placements, were recruited from six universities in South Korea. Exploratory and confirmatory factor analyses were performed and reliability and construct validity were assessed. The resulting instrument consisted of 19 items across four factors. Reliability of the four factors was acceptable and the validity was supported. The instrument was shown to be both valid and reliable for measuring nursing students' attitudes towards technology, thus aiding in the current understandings of this aspect. Through these measurements and understandings, nursing educators and students are able to be more reflexive of their attitudes and can thus seek to develop them positively. © 2015 John Wiley & Sons Ltd.

  20. Using Trusted Execution Environments in Two-factor Authentication: comparing approaches

    NARCIS (Netherlands)

    van Rijswijk, Roland M.; Poll, Erik

    Classic two-factor authentication has been around for a long time and has enjoyed success in certain markets (such as the corporate and the banking environ- ment). A reason for this success are the strong security properties, particularly where user interaction is concerned. These properties hinge

  1. Approaching the Affective Factors of Information Seeking: The Viewpoint of the Information Search Process Model

    Science.gov (United States)

    Savolainen, Reijo

    2015-01-01

    Introduction: The article contributes to the conceptual studies of affective factors in information seeking by examining Kuhlthau's information search process model. Method: This random-digit dial telephone survey of 253 people (75% female) living in a rural, medically under-serviced area of Ontario, Canada, follows-up a previous interview study…

  2. Vascular risk factors and Alzheimer’s disease. Therapeutic approaches in mouse models

    NARCIS (Netherlands)

    Wiesmann, M.

    2017-01-01

    The first aim of this thesis was to elucidate the impact of major vascular risk factors like hypertension, apoE4 and stroke during the very early phase of Alzheimer’s disease (AD) using several mice models. Hypertension has proven to be associated with cerebrovascular impairment already at young age

  3. Psychometric Evaluation of the Student Authorship Questionnaire: A Confirmatory Factor Analysis Approach

    Science.gov (United States)

    Ballantine, Joan; Guo, Xin; Larres, Patricia

    2015-01-01

    This research provides new insights into the measurement of students' authorial identity and its potential for minimising the incidence of unintentional plagiarism by providing evidence about the psychometric properties of the Student Authorship Questionnaire (SAQ). Exploratory and confirmatory factor analyses (EFA and CFA) are employed to…

  4. Approaches for Strengthening Causal Inference Regarding Prenatal Risk Factors for Childhood Behavioural and Psychiatric Disorders

    Science.gov (United States)

    Lewis, Sarah J.; Relton, Caroline; Zammit, Stanley; Smith, George Davey

    2013-01-01

    Background: The risk of childhood behavioural and psychiatric diseases could be substantially reduced if modifiable risk factors for these disorders were identified. The critical period for many of these exposures is likely to be in utero as this is the time when brain development is most rapid. However, due to confounding and other limitations of…

  5. Alternate Solution to Generalized Bernoulli Equations via an Integrating Factor: An Exact Differential Equation Approach

    Science.gov (United States)

    Tisdell, C. C.

    2017-01-01

    Solution methods to exact differential equations via integrating factors have a rich history dating back to Euler (1740) and the ideas enjoy applications to thermodynamics and electromagnetism. Recently, Azevedo and Valentino presented an analysis of the generalized Bernoulli equation, constructing a general solution by linearizing the problem…

  6. Finite Difference Methods for Option Pricing under Lévy Processes: Wiener-Hopf Factorization Approach

    Directory of Open Access Journals (Sweden)

    Oleg Kudryavtsev

    2013-01-01

    factorization identity. Notice that our algorithm has the same complexity as the ones which use the explicit-implicit scheme, with a tridiagonal matrix. However, our method is more accurate. We support the advantage of the new method in terms of accuracy and convergence by using numerical experiments.

  7. Trading Dynamics in the Foreign Exchange Market: A Latent Factor Panel Intensity Approach

    DEFF Research Database (Denmark)

    Nolte, Ingmar; Voev, Valeri

    2011-01-01

    We develop a panel intensity framework for the analysis of complex trading activity datasets containing detailed information on individual trading actions in different securities for a set of investors. A feature of the model is the presence of a time varying latent factor, which captures...

  8. Motivation: Approaching an Elusive Concept through the Factors That Shape It

    Science.gov (United States)

    Jang, Bong Gee; Conradi, Kristin; McKenna, Michael C.; Jones, Jill S.

    2015-01-01

    The main purpose of this article is to provide educators with clear definitions of motivational factors in reading so that instructional planning can capitalize on important distinctions. The authors present definitions of a small set of related motivational concepts (including attitudes, interests, self-efficacy, self-concept, goals, and value)…

  9. A generalized linear factor model approach to the hierarchical framework for responses and response times

    NARCIS (Netherlands)

    Molenaar, D.; Tuerlinckx, F.; van der Maas, H.L.J.

    2015-01-01

    We show how the hierarchical model for responses and response times as developed by van der Linden (2007), Fox, Klein Entink, and van der Linden (2007), Klein Entink, Fox, and van der Linden (2009), and Glas and van der Linden (2010) can be simplified to a generalized linear factor model with only

  10. Designing medical technology for resilience : integrating health economics and human factors approaches

    NARCIS (Netherlands)

    Borsci, Simone; Uchegbu, Ijeoma; Buckle, Peter; Ni, Zhifang; Walne, Simon; Hanna, George B.

    2018-01-01

    Introduction: The slow adoption of innovation into healthcare calls into question the manner of evidence generation for medical technology. This paper identifies potential reasons for this including a lack of attention to human factors, poor evaluation of economic benefits, lack of understanding of

  11. Dealing with Interpretability Issues in Predicting Firm Growth: Factor Analysis Approach

    Directory of Open Access Journals (Sweden)

    Bilandžić Ana

    2016-09-01

    Full Text Available Background: Alongside the theoretical progress made in understanding the factors that influence firm growth, many methodological challenges are yet to be overcome. Authors point to the notion of interpretability of growth prediction models as an important prerequisite for further advancement of the field as well as enhancement of models’ practical values.

  12. Factor Analysis vs. Fuzzy Sets Theory: Assessing the Influence of Different Techniques on Sen's Functioning Approach

    OpenAIRE

    Sara Lelli

    2001-01-01

    This paper explores a couple of specific operational interpretations of Sen's approach in view of assessing the extent to which the results originated by the implementation of Sen's concepts are influenced by the choice of the specific technique. By means of a survey based on a representative sample of Belgian individuals, seven achieved functioning's are identified via each technique and subsequently confronted. To structure the information and to facilitate comparisons, standard multivariat...

  13. Factors that affect micro-tooling features created by direct printing approach

    Science.gov (United States)

    Kumbhani, Mayur N.

    Current market required faster pace production of smaller, better, and improved products in shorter amount of time. Traditional high-rate manufacturing process such as hot embossing, injection molding, compression molding, etc. use tooling to replicate feature on a products. Miniaturization of many product in the field of biomedical, electronics, optical, and microfluidic is occurring on a daily bases. There is a constant need to produce cheaper, and faster tooling, which can be utilize by existing manufacturing processes. Traditionally, in order to manufacture micron size tooling features processes such as micro-machining, Electrical Discharge Machining (EDM), etc. are utilized. Due to a higher difficulty to produce smaller size features, and longer production cycle time, various additive manufacturing approaches are proposed, e.g. selective laser sintering (SLS), inkjet printing (3DP), fused deposition modeling (FDM), etc. were proposed. Most of these approaches can produce net shaped products from different materials such as metal, ceramic, or polymers. Several attempts were made to produce tooling features using additive manufacturing approaches. Most of these produced tooling were not cost effective, and the life cycle of these tooling was reported short. In this research, a method to produce tooling features using direct printing approach, where highly filled feedstock was dispensed on a substrate. This research evaluated different natural binders, such as guar gum, xanthan gum, and sodium carboxymethyl cellulose (NaCMC) and their combinations were evaluated. The best binder combination was then use to evaluate effect of different metal (316L stainless steel (3 mum), 316 stainless steel (45 mum), and 304 stainless steel (45 mum)) particle size on feature quality. Finally, the effect of direct printing process variables such as dispensing tip internal diameter (500 mum, and 333 mum) at different printing speeds were evaluated.

  14. Proteomic response to 5,6-dimethylxanthenone 4-acetic acid (DMXAA, vadimezan in human non-small cell lung cancer A549 cells determined by the stable-isotope labeling by amino acids in cell culture (SILAC approach

    Directory of Open Access Journals (Sweden)

    Pan ST

    2015-02-01

    Full Text Available Shu-Ting Pan,1,* Zhi-Wei Zhou,2,3,* Zhi-Xu He,3 Xueji Zhang,4 Tianxin Yang,5 Yin-Xue Yang,6 Dong Wang,7 Jia-Xuan Qiu,1 Shu-Feng Zhou2 1Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; 3Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guiyang Medical University, Guiyang, 4Research Center for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing, People’s Republic of China; 5Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, UT, USA; 6Department of Colorectal Surgery, General Hospital of Ningxia Medical University, Yinchuan, 7Cancer Center, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing, People’s Republic of China *These two authors contributed equally to this work Abstract: 5,6-Dimethylxanthenone 4-acetic acid (DMXAA, also known as ASA404 and vadimezan, is a potent tumor blood vessel-disrupting agent and cytokine inducer used alone or in combination with other cytotoxic agents for the treatment of non-small cell lung cancer (NSCLC and other cancers. However, the latest Phase III clinical trial has shown frustrating outcomes in the treatment of NSCLC, since the therapeutic targets and underlying mechanism for the anticancer effect of DMXAA are not yet fully understood. This study aimed to examine the proteomic response to DMXAA and unveil the global molecular targets and possible mechanisms for the anticancer effect of DMXAA in NSCLC A549 cells using a stable-isotope labeling by amino acids in cell culture (SILAC approach. The proteomic data showed that treatment with DMXAA

  15. The possibilities of suicide prevention in adolescents. A holistic approach to protective and risk factors.

    Science.gov (United States)

    Kalmár, Sándor

    2013-03-01

    There is no other such complex physical, biological, somatic, mental, psychological, psychiatric, cultural, social and spiritual phenomenon and general public health problem, so much unexplained, meaningless, so tragic, painful, and unreasonable, so difficult, contradictory and mystified like suicide. In spite of the several already identified background factors, we do not and we can not know the real reasons behind suicide, because suicide is multi-causal, and can never be traced back to one single cause, but there are always many biological, psychological-psychiatric, historical, social and cultural factors involved in its development. However, the strongest suicide risk factor is an unrecognized and untreated mental disorder. Suicide among young people is one of the most serious public health problems. In Hungary 1395 young people lost their lives due to suicide in the 24> age group between 2000-2010, 1150 males and 245 females. According to epidemiological studies, 24.7% of children and adolescents suffer from some form of behaviour-, conduct- or other psychiatric disorders. Among adolescents (aged 15-24) suicide was the first leading cause of death in 2010. Despite great advances in the psychopharmacology and psychotherapy of mental disorders, suicides persist as a major cause of mortality, especially among the 15-24-year old population. Victims of suicide are not healthy individuals. They always suffer from psychiatric or mental, physical or somatic, cultural (social, historical, mythological) and spiritual disorders. The author tries to classify suicide protective and risk factors according to physical-biological, mental-psychological, cultural-social, and spiritual aspects. However, it must be remembered that these factors are not necessarily present in each and every case and may vary from one country to another, one person to another, depending on cultural, political, (spiritual) and economical features. Risk and protective factors can occur (1) at the

  16. Dynamic SPECT reconstruction from few projections: a sparsity enforced matrix factorization approach

    Science.gov (United States)

    Ding, Qiaoqiao; Zan, Yunlong; Huang, Qiu; Zhang, Xiaoqun

    2015-02-01

    The reconstruction of dynamic images from few projection data is a challenging problem, especially when noise is present and when the dynamic images are vary fast. In this paper, we propose a variational model, sparsity enforced matrix factorization (SEMF), based on low rank matrix factorization of unknown images and enforced sparsity constraints for representing both coefficients and bases. The proposed model is solved via an alternating iterative scheme for which each subproblem is convex and involves the efficient alternating direction method of multipliers (ADMM). The convergence of the overall alternating scheme for the nonconvex problem relies upon the Kurdyka-Łojasiewicz property, recently studied by Attouch et al (2010 Math. Oper. Res. 35 438) and Attouch et al (2013 Math. Program. 137 91). Finally our proof-of-concept simulation on 2D dynamic images shows the advantage of the proposed method compared to conventional methods.

  17. Depth factors for undrained bearing capacity of circular footing by numerical approach

    Directory of Open Access Journals (Sweden)

    Sadok Benmebarek

    2017-08-01

    Full Text Available The undrained vertical bearing capacity of embedded foundation has been extensively studied using analytical and numerical methods. Through comparing the results of a circular embedded foundation in the literature, a significant difference between the bearing capacity factors and depth factors is observed. Based on the previous research findings, numerical computations using FLAC code are carried out in this study to evaluate the undrained bearing capacity of circular foundations with embedment ratios up to five for different base and side foundation roughness conditions. Unlike the foundation base, the roughness of the foundation side has a significant effect on the bearing capacity. The comparison of the present results with numerical studies available in the literature shows that the discrepancy is related to the procedures used to simulate the foundation side interface conditions and to the estimation of the bearing capacity.

  18. Bibliometric approach of factors affecting scientific productivity in environmental sciences and ecology.

    Science.gov (United States)

    Dragos, Cristian Mihai; Dragos, Simona Laura

    2013-04-01

    Different academic bibliometric studies have measured the influence of economic, political and linguistic factors in the academic output of countries. Separate analysis in different fields can reveal specific incentive factors. Our study proves that the Environmental Performance Index, computed by Yale University, is highly significant (pecology. The control variables like education financing, publishing of ISI Thomson domestic journals and the English language are also significant. The methodology uses Ordinary Least Squares multiple regressions with convincing results (R(2)=0.752). The relative positions of the 92 countries in the sample are also discussed. We draw up a ranking of the countries' concern for the environment, considering evenly the scientific productivity and the environment quality. We notice huge differences concerning the number of inhabitants and population income between the countries that dominate the classification and those occupying the last positions. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Pesticides exposure as etiological factors of Parkinson's disease and other neurodegenerative diseases--a mechanistic approach.

    Science.gov (United States)

    Baltazar, Maria Teresa; Dinis-Oliveira, Ricardo Jorge; de Lourdes Bastos, Maria; Tsatsakis, Aristidis M; Duarte, José Alberto; Carvalho, Félix

    2014-10-15

    The etiology of most neurodegenerative disorders is multifactorial and consists of an interaction between environmental factors and genetic predisposition. The role of pesticide exposure in neurodegenerative disease has long been suspected, but the specific causative agents and the mechanisms underlying are not fully understood. For the main neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis there are evidences linking their etiology with long-term/low-dose exposure to pesticides such as paraquat, maneb, dieldrin, pyrethroids and organophosphates. Most of these pesticides share common features, namely the ability to induce oxidative stress, mitochondrial dysfunction, α-synuclein fibrillization and neuronal cell loss. This review aims to clarify the role of pesticides as environmental risk factors in genesis of idiopathic PD and other neurological syndromes. For this purpose, the most relevant epidemiological and experimental data is highlighted in order to discuss the molecular mechanisms involved in neurodegeneration. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Key factors contributing to accident severity rate in construction industry in Iran: a regression modelling approach.

    Science.gov (United States)

    Soltanzadeh, Ahmad; Mohammadfam, Iraj; Moghimbeigi, Abbas; Ghiasvand, Reza

    2016-03-01

    Construction industry involves the highest risk of occupational accidents and bodily injuries, which range from mild to very severe. The aim of this cross-sectional study was to identify the factors associated with accident severity rate (ASR) in the largest Iranian construction companies based on data about 500 occupational accidents recorded from 2009 to 2013. We also gathered data on safety and health risk management and training systems. Data were analysed using Pearson's chi-squared coefficient and multiple regression analysis. Median ASR (and the interquartile range) was 107.50 (57.24- 381.25). Fourteen of the 24 studied factors stood out as most affecting construction accident severity (p<0.05). These findings can be applied in the design and implementation of a comprehensive safety and health risk management system to reduce ASR.

  1. A new FACS approach isolates hESC derived endoderm using transcription factors.

    Directory of Open Access Journals (Sweden)

    Yuqiong Pan

    2011-03-01

    Full Text Available We show that high quality microarray gene expression profiles can be obtained following FACS sorting of cells using combinations of transcription factors. We use this transcription factor FACS (tfFACS methodology to perform a genomic analysis of hESC-derived endodermal lineages marked by combinations of SOX17, GATA4, and CXCR4, and find that triple positive cells have a much stronger definitive endoderm signature than other combinations of these markers. Additionally, SOX17(+ GATA4(+ cells can be obtained at a much earlier stage of differentiation, prior to expression of CXCR4(+ cells, providing an important new tool to isolate this earlier definitive endoderm subtype. Overall, tfFACS represents an advancement in FACS technology which broadly crosses multiple disciplines, most notably in regenerative medicine to redefine cellular populations.

  2. Determination of UTW K/sub XSi/ factors for low atomic number microanalysis: A systematic approach

    International Nuclear Information System (INIS)

    Krishnan, K.M.; Echer, C.J.

    1987-07-01

    A systematic measurement of experimental K/sub XSi/ factors, with particular emphasis on low Z microanalysis (6 ≤ 7 ≤ 32), at 200 kV for a KEVEX UTW Si(Li) detector fitted to a JEOL 200CX analytical microscope, using a variety of high purity standards has been carried out. Under normal operating conditions of a LaB 6 filament, it is shown that absorption in the specimen is very critical, particularly for heavy element matrices, and sample thicknesses need to be measured for accurate microanalysis of low Z elements (C,N,O). Using these measured K/sub XSi/ factors, quantitative UTW-EDX microanalysis has been routinely extended to carbon. 21 refs

  3. Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

    Energy Technology Data Exchange (ETDEWEB)

    Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J., E-mail: ortoleva@indiana.edu [Center for Cell and Virus Theory, Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405 (United States)

    2014-02-21

    Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation.

  4. A combinatorial approach to synthetic transcription factor-promoter combinations for yeast strain engineering

    DEFF Research Database (Denmark)

    Dossani, Zain Y.; Apel, Amanda Reider; Szmidt-Middleton, Heather

    2018-01-01

    . Correspondingly, the synthetic transcription factor (TF) consists of the DNA binding domain of the LexA protein, fused with the human estrogen binding domain and the viral activator domain, VP16. The resulting system with a bacterial DNA binding domain avoids the transcription of native S. cerevisiae genes...... regions, we have built a library of hybrid promoters that are regulated by a synthetic transcription factor. The hybrid promoters consist of native S. cerevisiae promoters, in which the operator regions have been replaced with sequences that are recognized by the bacterial LexA DNA binding protein...... levels, using the same synthetic TF and a given estradiol. This set of promoters, in combination with our synthetic TF, has the potential to regulate numerous genes or pathways simultaneously, to multiple desired levels, in a single strain....

  5. Antecedents Factors that Influence Soy Consumption: A Structural Equation Modeling Approach

    OpenAIRE

    Balasubramanian, Siva K.; Moon, Wanki; Rimal, Arbindra; Coker, Kesha

    2009-01-01

    We propose a structural model of antecedent factors that affect the frequency of soy consumption. This model, suggests that soy-general knowledge influences perceptions about nutrition concern, health benefits of soy, soy related personal beliefs and personal attitudes toward soy. Health benefits of soy, in turn, impacts soy-related personal beliefs and personal attitudes toward soy. Additionally, soy-related personal beliefs influence personal attitudes toward soy. Finally, both nutrition co...

  6. Analyzing the impact of social factors on homelessness: a Fuzzy Cognitive Map approach

    OpenAIRE

    Mago, Vijay K; Morden, Hilary K; Fritz, Charles; Wu, Tiankuang; Namazi, Sara; Geranmayeh, Parastoo; Chattopadhyay, Rakhi; Dabbaghian, Vahid

    2013-01-01

    Background The forces which affect homelessness are complex and often interactive in nature. Social forces such as addictions, family breakdown, and mental illness are compounded by structural forces such as lack of available low-cost housing, poor economic conditions, and insufficient mental health services. Together these factors impact levels of homelessness through their dynamic relations. Historic models, which are static in nature, have only been marginally successful in capturing th...

  7. A Study on Influencing Factors of Knowledge Management Systems Adoption: Models Comparison Approach

    OpenAIRE

    Mei-Chun Yeh; Ming-Shu Yuan

    2007-01-01

    Using Linear Structural Relation model (LISREL model) as analysis method and technology acceptance model and decomposed theory of planned behavior as research foundation, this study approachesmainly from the angle of behavioral intention to examine the influential factors of 421 employees adopting knowledge management systems and in the meantime to compare the two method models mentioned on the top. According to the research, there is no, in comparison with technology acceptance model anddeco...

  8. An alternative approach for addressing the failure probability-safety factor method with sensitivity analysis

    International Nuclear Information System (INIS)

    Castillo, Enrique; Conejo, Antonio J.; Minguez, Roberto; Castillo, Carmen

    2003-01-01

    The paper introduces a method for solving the failure probability-safety factor problem for designing engineering works proposed by Castillo et al. that optimizes an objective function subject to the standard geometric and code constraints, and two more sets of constraints that simultaneously guarantee given safety factors and failure probability bounds associated with a given set of failure modes. The method uses the dual variables and is especially convenient to perform a sensitivity analysis, because sensitivities of the objective function and the reliability indices can be obtained with respect to all data values. To this end, the optimization problems are transformed into other equivalent ones, in which the data parameters are converted into artificial variables, and locked to their actual values. In this way, some variables of the associated dual problems become the desired sensitivities. In addition, using the proposed methodology, calibration of codes based on partial safety factors can be done. The method is illustrated by its application to the design of a simple rubble mound breakwater and a bridge crane

  9. Dimensional approach to delusions in psychotic depression in the elderly: factor structure and clinical correlates.

    Science.gov (United States)

    Gournellis, Rossetos; Oulis, Panagiotis; Michalopoulou, Panagiota; Kaparoudaki, Adamantia; Dimitrakopoulos, Christos; Lykouras, Lefteris

    2009-04-01

    The present study attempted to investigate the clinically important broader dimensions of clinical characteristics of delusions, through multivariate analysis, in a pure sample of elderly unipolar delusional depressives as well as to test their external validity against a set of demographic, anamnestic and psychopathological validators. Fifty inpatients suffering from psychotic major depression (PMD) in the context of major depressive disorder, 60 years old or older, were assessed on the basis of SCID IV, HRSD, MMSE and by three-point ordinal scales of 12 clinical, intrinsic or relational characteristics of delusions tested for their inter-rater reliability. Principal Component Analysis resulted in the extraction of five factors, jointly accounting for 69.7% of the total variance. The five factors were interpreted as representing the dimensions of delusional strength, acute upsetting, delusional organization, incomprehensibility and incitation to actions. Most of the factors were differentially associated with patients' demographic, anamnestic and clinical variables. Our results overlap in part with those of another similar study in delusional depressives of all age-ranges, differing, however, in respects possibly attributable to peculiarities of elderly depressives. Overall, the findings of the present study contribute to the further elucidation of major clinical dimensions of delusions in PMD in the elderly and the testing of their external validity. (c) 2008 John Wiley & Sons, Ltd.

  10. Contextual Factors Affecting the Innovation Performance of Manufacturing SMEs in Korea: A Structural Equation Modeling Approach

    Directory of Open Access Journals (Sweden)

    Ye Seul Choi

    2017-07-01

    Full Text Available This study empirically explores the relationship between innovation performance and the internal and contextual factors driving technological innovation in manufacturing small and medium-sized enterprises (SMEs in metropolitan areas of Korea using structural equation modeling (SEM. Our analysis is based on firm-level data from the Korean Innovation Survey conducted by the Science and Technology Policy Institute in 2012. According to the results, SMEs’ innovation capacity was positively related to technological innovation performance, and SMEs’ skills and technology acquisition is a contextual factor that positively influences their innovation performance. In this process, SMEs’ innovation capacity is a partial mediator between skills and technology acquisition and SMEs’ technological innovation performance. Moreover, the results show that the relationship between government and public policies and SMEs’ innovation performance is mediated by SMEs’ internal innovation capacity. The results imply that both skills and technology acquisition and government and public policies are important contextual factors can increase SMEs’ innovation performance. Based on the results, this study provides implications for policy makers in terms of the policies that provide both direct and support roles in fostering and sustaining innovation, which drives regional economic growth and development.

  11. Defining the "urban" in urbanization and health: a factor analysis approach.

    Science.gov (United States)

    McDade, T W; Adair, L S

    2001-07-01

    Urban environments have been linked to a range of human health issues, and as the pace of urbanization accelerates, new challenges arise to characterize these environments, and to understand their positive and negative implications for health. We seek to contribute to future studies of urbanization and health by exploring multiple definitions of urbanicity in the Philippines, using data from an ongoing, longitudinal study. We use factor analysis to identify meaningful clusters of household- and community-level variables, and to generate factor scores that summarize each household's position with respect to access to infrastructure and health services, and level of affluence. Factor scores are considered for 1983 and 1994 to assess the type and pace of change that has occurred in the Philippines, and scores are compared across urban and rural areas, and across six different settlement types, to explore household- and community-level markers of urbanicity. This analysis demonstrates the heterogeneity of environments within urban and rural areas, and emphasizes the need for a finer level of investigation in future studies of urbanization and health.

  12. Contextual approach to technology assessment: Implications for one-factor fix solutions to complex social problems

    Science.gov (United States)

    Mayo, L. H.

    1975-01-01

    The contextual approach is discussed which undertakes to demonstrate that technology assessment assists in the identification of the full range of implications of taking a particular action and facilitates the consideration of alternative means by which the total affected social problem context might be changed by available project options. It is found that the social impacts of an application on participants, institutions, processes, and social interests, and the accompanying interactions may not only induce modifications in the problem contest delineated for examination with respect to the design, operations, regulation, and use of the posited application, but also affect related social problem contexts.

  13. Dynamical attraction to stable processes

    OpenAIRE

    Fisher, Albert M.; Talet, Marina

    2012-01-01

    We apply dynamical ideas within probability theory, proving an almost-sure invariance principle in log density for stable processes. The familiar scaling property (self-similarity) of the stable process has a stronger expression, that the scaling flow on Skorokhod path space is a Bernoulli flow. We prove that typical paths of a random walk with i.i.d. increments in the domain of attraction of a stable law can be paired with paths of a stable process so that, after applying a non-random regula...

  14. Stable Treemaps via Local Moves.

    Science.gov (United States)

    Sondag, Max; Speckmann, Bettina; Verbeek, Kevin

    2018-01-01

    Treemaps are a popular tool to visualize hierarchical data: items are represented by nested rectangles and the area of each rectangle corresponds to the data being visualized for this item. The visual quality of a treemap is commonly measured via the aspect ratio of the rectangles. If the data changes, then a second important quality criterion is the stability of the treemap: how much does the treemap change as the data changes. We present a novel stable treemapping algorithm that has very high visual quality. Whereas existing treemapping algorithms generally recompute the treemap every time the input changes, our algorithm changes the layout of the treemap using only local modifications. This approach not only gives us direct control over stability, but it also allows us to use a larger set of possible layouts, thus provably resulting in treemaps of higher visual quality compared to existing algorithms. We further prove that we can reach all possible treemap layouts using only our local modifications. Furthermore, we introduce a new measure for stability that better captures the relative positions of rectangles. We finally show via experiments on real-world data that our algorithm outperforms existing treemapping algorithms also in practice on either visual quality and/or stability. Our algorithm scores high on stability regardless of whether we use an existing stability measure or our new measure.

  15. Factors Associated with Successful Mentoring of Parents Addressing Childhood Obesity: A Mixed Methods Approach

    Directory of Open Access Journals (Sweden)

    Gabriela Abigail Villanueva

    2016-01-01

    Full Text Available Objective. Parents mentoring other parents as a behavioral intervention for child obesity is novel with limited data describing the experience and dynamics of this approach. This study aimed to describe the experiences of parent mentors and the self-efficacy and attitudes of their mentees in the context of a clinical trial for childhood obesity. Methods. The context for this study was a randomized clinical trial using either parent mentors or a community health worker engaging parents of obese children in behavioral change over six months. Parent mentors were interviewed at the mid-point of the intervention using a semistructured questionnaire to elicit their perceptions and experiences during the process of mentoring. Parent mentees completed a survey assessing their self-efficacy, perception of the parent mentor, and attitudes and beliefs related to their child’s weight. Results. The qualitative analysis of parent mentor interviews indicated high commitment despite their nonprofessional status, facing challenges of engagement with fellow parents and attitudes of persistence and being nonjudgmental. The parent mentee ratings of parent mentors were overall very high and similar to the ratings of a community health worker (paraprofessional. Conclusion. The data suggest that a parent mentor model of intervention for child obesity is an acceptable mode of approaching behavior change in the Hispanic population around childhood obesity with potential for scalability if proven effective.

  16. A novel approach for long-term determination of indoor 222Rn progeny equilibrium factor using nuclear track detectors

    Science.gov (United States)

    Amgarou, K.; Font, Ll.; Baixeras, C.

    2003-06-01

    A detailed study of the measurement principles of airborne 222Rn decay products by means of nuclear track detectors (NTDs), taking into account the range of variation of the parameters influencing their concentration indoors, has shown that it is not possible for the existing methods to obtain the associated long-term equilibrium factor with an appropriate accuracy. For this reason, we have established a novel approach based on the new concept of reduced equilibrium factor, which can be obtained from the only measurement of airborne 222Rn and its α-emitter daughter ( 218Po and 214Po) concentrations using a passive, integrating and multi-component system of NTDs. We have found that the equilibrium factor has a linear dependence on the reduced equilibrium factor regardless the values taken for the rates of ventilation, of aerosol attachment and of surface deposition. By using well-controlled exposures in a reference laboratory, we have shown that the equilibrium factor values determined with our system agree with those obtained by active monitors. Finally, as a pilot test, several dosimeters were exposed in an inhabited Swedish single-family house. The results of this exposure suggest the usefulness of this method to perform routine surveys in private homes and in workplaces in order to estimate the annual effective dose received by the general public and the workers due to the presence of 222Rn daughters.

  17. Fitted-Stable Finite Difference Method for Singularly Perturbed Two ...

    African Journals Online (AJOL)

    A fitted-stable central difference method is presented for solving singularly perturbed two point boundary value problems with the boundary layer at one end (left or right) of the interval. A fitting factor is introduced in second order stable central difference scheme (SCD Method) and its value is obtained using the theory of ...

  18. Human Factors and Organizational Issues in 2015: The Increasing Complexity of the Healthcare Domain Calls for More Comprehensive Approaches

    Science.gov (United States)

    2016-01-01

    Summary Objective To summarize significant research contributions on human factors and organizational issues in medical informatics published in 2015. Methods An extensive search using PubMed/Medline and Web of Science® was conducted to identify the scientific contributions published in 2015 that address human factors and organizational issues in medical informatics. The selection process comprised three steps: (i) 15 candidate best papers were first selected by the two section editors, (ii) external reviewers from internationally renowned research teams reviewed each candidate best paper, and (iii) the final selection of five best papers was conducted by the editorial board of the Yearbook. Results Noteworthy papers in 2015 emphasize the increasing complexity of the healthcare environment. They call for more comprehensive approaches and evaluation studies. All provide a real added-value in this direction. Conclusion There is no more need to promote the contribution of human factors and ergonomics (HFE) approaches to health IT-related risks and patient safety. However, there is still a need for research on HFE methods to adapt health information technology tools to the complexity of the healthcare domain. PMID:27830240

  19. Support stance in carers of adults with eating disorders: Factors associated with collaborative versus directive approaches.

    Science.gov (United States)

    Geller, Josie; Srikameswaran, Suja; Iyar, Megumi; Zelichowska, Joanna; Thibodeau, Michel; Brown, Krista E; Dunn, Erin C

    2017-05-01

    The support provided by family and friends is integral to patient motivation and clinical outcomes across health care populations. However, little is known about factors that promote or interfere with the type of support offered. This research examined factors associated with collaborative versus directive support among carers of adults with eating disorders. Participants were mothers, fathers, partners, friends, and siblings (N = 141) of eating disorder patients in hospital or residential treatment. Two methodologies were used to assess directive and collaborative support stance: a questionnaire of support behaviors and coded responses to clinical vignettes. Measures of interpersonal functioning, psychiatric distress, caregiving experience, and closeness with their loved one were also completed. Although carers rated a collaborative stance as more helpful than a directive stance, 60% of responses to the clinical vignettes were directive. Across both methodologies, collaborative support behaviors were associated with beliefs about helpful support and with a less vindictive and cold interpersonal style. Whereas use of a directive support stance was exclusively associated with negative caregiving experiences, collaborative responses were associated with both positive and negative experiences. Although the benefits of collaborative support have been well established, this is the first study to examine factors associated with the use of support stance. Findings suggest a number of ways to help carers create and maintain collaborative relationships, including addressing beliefs and interpersonal style and capitalizing on both positive and negative experiences with their loved one. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:498-505). © 2016 Wiley Periodicals, Inc.

  20. Manual for the Use of Stable Isotopes in Entomology

    International Nuclear Information System (INIS)

    2009-06-01

    result of problem driven inquisitiveness and technological advances, and are framed by the social and political environment. Although the external environment may mould the technological path, a technology will only become obsolete if there are viable substitution products or methods. Stable isotope methods are a substitute for many radionuclide methods. The progress made in stable isotope science over the past twenty years is a direct result of the interplay of the above factors. Stable isotopes are omnipresent in the environment and pose no health or environmental risks. Advances in isotope ratio mass spectrometry in terms of detection, accuracy and automation have broadened experimental possibilities immensely over the past twenty years. It was recognised that there was significant potential for answering many of the entomologist?s biological and ecological questions using stable isotopes, an expertise the Soil Science Unit of the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf had long fostered; therefore collaboration with the Entomology Unit at the same Laboratory was established. A number of collaborative experiments were carried and subsequently published. It was soon recognised that stable isotopes have tremendous potential in entomological research and although there were numerous studies using stable isotopes in ecology, their use in entomology per se was limited. Thus it was felt that a publication was required to make stable isotope techniques more widely known among entomologists. This manual will attempt to provide an introduction to the use of stable isotopes in entomological research. It will strive to communicate the basic principles and techniques of stable isotope science and provide a springboard for further interest and research in this area

  1. Computational Approach to Characterize Causative Factors and Molecular Indicators of Chronic Wound Inflammation

    Science.gov (United States)

    2014-01-01

    necrosis factor receptor p55-deficient mice with reduced leukocyte infiltration. FASEB J. 16: 963–974. 59. Brancato, S. K., and J. E. Albina . 2011...Reichner, and J. E. Albina . 2010. The phenotype of murine wound macrophages. J. Leukoc. Biol. 87: 59–67. 73. Jenkins, S. J., D. Ruckerl, P. C. Cook...Regen. 20: 38–49. 85. Thomay, A. A., J. M. Daley, E. Sabo, P. J. Worth, L. J. Shelton, M. W. Harty, J. S. Reichner, and J. E. Albina . 2009. Disruption of

  2. Mayaro Virus Infection in Amazonia: A Multimodel Inference Approach to Risk Factor Assessment

    Science.gov (United States)

    de Paula, Vanessa S.; Figueiredo, Luiz T. M.; Braga, Wornei S. M.; Luz, Sérgio L. B.

    2012-01-01

    Background Arboviral diseases are major global public health threats. Yet, our understanding of infection risk factors is, with a few exceptions, considerably limited. A crucial shortcoming is the widespread use of analytical methods generally not suited for observational data – particularly null hypothesis-testing (NHT) and step-wise regression (SWR). Using Mayaro virus (MAYV) as a case study, here we compare information theory-based multimodel inference (MMI) with conventional analyses for arboviral infection risk factor assessment. Methodology/Principal Findings A cross-sectional survey of anti-MAYV antibodies revealed 44% prevalence (n = 270 subjects) in a central Amazon rural settlement. NHT suggested that residents of village-like household clusters and those using closed toilet/latrines were at higher risk, while living in non-village-like areas, using bednets, and owning fowl, pigs or dogs were protective. The “minimum adequate” SWR model retained only residence area and bednet use. Using MMI, we identified relevant covariates, quantified their relative importance, and estimated effect-sizes (β±SE) on which to base inference. Residence area (β Village = 2.93±0.41; β Upland = −0.56±0.33, β Riverbanks = −2.37±0.55) and bednet use (β = −0.95±0.28) were the most important factors, followed by crop-plot ownership (β = 0.39±0.22) and regular use of a closed toilet/latrine (β = 0.19±0.13); domestic animals had insignificant protective effects and were relatively unimportant. The SWR model ranked fifth among the 128 models in the final MMI set. Conclusions/Significance Our analyses illustrate how MMI can enhance inference on infection risk factors when compared with NHT or SWR. MMI indicates that forest crop-plot workers are likely exposed to typical MAYV cycles maintained by diurnal, forest dwelling vectors; however, MAYV might also be circulating in nocturnal, domestic-peridomestic cycles in village-like areas

  3. Analyzing the impact of social factors on homelessness: a fuzzy cognitive map approach.

    Science.gov (United States)

    Mago, Vijay K; Morden, Hilary K; Fritz, Charles; Wu, Tiankuang; Namazi, Sara; Geranmayeh, Parastoo; Chattopadhyay, Rakhi; Dabbaghian, Vahid

    2013-08-23

    The forces which affect homelessness are complex and often interactive in nature. Social forces such as addictions, family breakdown, and mental illness are compounded by structural forces such as lack of available low-cost housing, poor economic conditions, and insufficient mental health services. Together these factors impact levels of homelessness through their dynamic relations. Historic models, which are static in nature, have only been marginally successful in capturing these relationships. Fuzzy Logic (FL) and fuzzy cognitive maps (FCMs) are particularly suited to the modeling of complex social problems, such as homelessness, due to their inherent ability to model intricate, interactive systems often described in vague conceptual terms and then organize them into a specific, concrete form (i.e., the FCM) which can be readily understood by social scientists and others. Using FL we converted information, taken from recently published, peer reviewed articles, for a select group of factors related to homelessness and then calculated the strength of influence (weights) for pairs of factors. We then used these weighted relationships in a FCM to test the effects of increasing or decreasing individual or groups of factors. Results of these trials were explainable according to current empirical knowledge related to homelessness. Prior graphic maps of homelessness have been of limited use due to the dynamic nature of the concepts related to homelessness. The FCM technique captures greater degrees of dynamism and complexity than static models, allowing relevant concepts to be manipulated and interacted. This, in turn, allows for a much more realistic picture of homelessness. Through network analysis of the FCM we determined that Education exerts the greatest force in the model and hence impacts the dynamism and complexity of a social problem such as homelessness. The FCM built to model the complex social system of homelessness reasonably represented reality for the

  4. Mayaro virus infection in amazonia: a multimodel inference approach to risk factor assessment.

    Directory of Open Access Journals (Sweden)

    Fernando Abad-Franch

    Full Text Available BACKGROUND: Arboviral diseases are major global public health threats. Yet, our understanding of infection risk factors is, with a few exceptions, considerably limited. A crucial shortcoming is the widespread use of analytical methods generally not suited for observational data--particularly null hypothesis-testing (NHT and step-wise regression (SWR. Using Mayaro virus (MAYV as a case study, here we compare information theory-based multimodel inference (MMI with conventional analyses for arboviral infection risk factor assessment. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional survey of anti-MAYV antibodies revealed 44% prevalence (n = 270 subjects in a central Amazon rural settlement. NHT suggested that residents of village-like household clusters and those using closed toilet/latrines were at higher risk, while living in non-village-like areas, using bednets, and owning fowl, pigs or dogs were protective. The "minimum adequate" SWR model retained only residence area and bednet use. Using MMI, we identified relevant covariates, quantified their relative importance, and estimated effect-sizes (β ± SE on which to base inference. Residence area (β(Village  =  2.93 ± 0.41; β(Upland = -0.56 ± 0.33, β(Riverbanks  =  -2.37 ± 0.55 and bednet use (β = -0.95 ± 0.28 were the most important factors, followed by crop-plot ownership (β  =  0.39 ± 0.22 and regular use of a closed toilet/latrine (β = 0.19 ± 0.13; domestic animals had insignificant protective effects and were relatively unimportant. The SWR model ranked fifth among the 128 models in the final MMI set. CONCLUSIONS/SIGNIFICANCE: Our analyses illustrate how MMI can enhance inference on infection risk factors when compared with NHT or SWR. MMI indicates that forest crop-plot workers are likely exposed to typical MAYV cycles maintained by diurnal, forest dwelling vectors; however, MAYV might also be circulating in nocturnal, domestic-peridomestic cycles

  5. Investigating the management information needs of academic Heads of Department: a Critical Success Factors approach

    Directory of Open Access Journals (Sweden)

    Francis Green

    1996-01-01

    Full Text Available This paper describes a research project in the Department of Information Studies at the University of Sheffield. With funding from the British Library Research and Development Department a critical success factors-based investigation of the management information needs of academic Heads of Department in an number of English universities was undertaken in 1994/1995, following publication of the results of a pilot study byPellow and Wilson (1993. Senior academic staff, university administrators and librarians in sixteen universities were interviewed between December, 1994 and March, 1995. Collation of data and analysis of results have been completed

  6. A human factors approach to observation chart design can trump health professionals' prior chart experience.

    Science.gov (United States)

    Christofidis, Melany J; Hill, Andrew; Horswill, Mark S; Watson, Marcus O

    2013-05-01

    To determine whether experienced health professionals recognise patient deterioration more accurately and efficiently using (a) novel observation charts, designed from a human factors perspective, or (b) chart designs with which they have long-term experience. Participants were 101 health professionals experienced in using either a multiple parameter track-and-trigger chart or a graphical chart with no track-and-trigger system. Participants were presented with realistic abnormal and normal patient observations recorded on six hospital observation charts of varying design quality, including the chart that participants were familiar with (or a very similar design). Across 48 trials, the participant was asked to specify if any of the vital sign observations were abnormal, or if all of the observations were normal. Participants' overall error rates (i.e., proportion of incorrect responses) and response times, the main outcome measures, were calculated for each observation chart. Participants made significantly fewer errors and responded significantly faster when using a novel user-friendly chart compared with all the other designs, including the charts that they were experienced with in a clinical setting. The findings suggest that, at least in the contexts examined, superior observation chart design appears to trump familiarity. Hence, hospitals motivated to improve the detection of patient deterioration should implement charts designed from a human factors perspective, rather than simply maintaining the status quo of reliance on clinical experience. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. The Journal Impact Factor: Moving Toward an Alternative and Combined Scientometric Approach.

    Science.gov (United States)

    Gasparyan, Armen Yuri; Nurmashev, Bekaidar; Yessirkepov, Marlen; Udovik, Elena E; Baryshnikov, Aleksandr A; Kitas, George D

    2017-02-01

    The Journal Impact Factor (JIF) is a single citation metric, which is widely employed for ranking journals and choosing target journals, but is also misused as the proxy of the quality of individual articles and academic achievements of authors. This article analyzes Scopus-based publication activity on the JIF and overviews some of the numerous misuses of the JIF, global initiatives to overcome the 'obsession' with impact factors, and emerging strategies to revise the concept of the scholarly impact. The growing number of articles on the JIF, most of which are in English, reflects interest of experts in journal editing and scientometrics toward its uses, misuses, and options to overcome related problems. Solely displaying values of the JIFs on the journal websites is criticized by experts as these average metrics do not reflect skewness of citation distribution of individual articles. Emerging strategies suggest to complement the JIFs with citation plots and alternative metrics, reflecting uses of individual articles in terms of downloads and distribution of related information through social media and networking platforms. It is also proposed to revise the original formula of the JIF calculation and embrace the concept of the impact and importance of individual articles. The latter is largely dependent on ethical soundness of the journal instructions, proper editing and structuring of articles, efforts to promote related information through social media, and endorsements of professional societies.

  8. A data mining approach to investigate the factors influencing the crash severity of motorcycle pillion passengers.

    Science.gov (United States)

    Tavakoli Kashani, Ali; Rabieyan, Rahim; Besharati, Mohammad Mehdi

    2014-12-01

    Motorcycle passengers comprise a considerable proportion of traffic crash victims. During a 5 year period (2006-2010) in Iran, an average of 3.4 pillion passengers are killed daily due to motorcycle crashes. This study investigated the main factors influencing crash severity of this group of road users. The Classification and Regression Trees (CART) method was employed to analyze the injury severity of pillion passengers in Iran over a 4 y ear period (2009-2012). The predictive accuracy of the model built with a total of 16 variables was 74%, which showed a considerable improvement compared to previous studies. The results indicate that area type, land use, and injured part of the body (head, neck, etc.) are the most influential factors affecting the fatality of motorcycle passengers. Results also show that helmet usage could reduce the fatality risk among motorcycle passengers by 28%. The findings of this study might help develop more targeted countermeasures to reduce the death rate of motorcycle pillion passengers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. An expert performance approach to examining factors contributing to academic success in organic chemistry

    Science.gov (United States)

    Nandagopal, Kiruthiga

    Successful completion of the introductory course in organic chemistry is a prerequisite for many graduate and professional science programs, yet the failure rate for this course is notoriously high. To date, there have been few studies examining factors contributing to academic success in organic chemistry. This study demonstrates that the online, longitudinal methods used by investigations of expert performance can examine and successfully identify factors contributing to academic success at the college level. Sixty-four students enrolled in introductory organic chemistry during the Fall 2007 and Spring 2008 semesters completed motivation questionnaires, interviews, diaries, and think-aloud reading and problem-solving tasks at three different points across a semester. Measures of spatial ability, general ability, and background preparation were also collected. Each measure was analyzed to determine significant differences between groups differing in grade-point average (GPA) prior to the start of the course and to identify predictors of organic chemistry grade. Variables measuring background preparation, problem-solving strategies and studying strategies were found to be the best predictors of academic success in organic chemistry. Implications for instruction in organic chemistry and effective studying behaviors are discussed.

  10. Factors of adoption of mobile information technology by homecare nurses: a technology acceptance model 2 approach.

    Science.gov (United States)

    Zhang, Huiying; Cocosila, Mihail; Archer, Norm

    2010-01-01

    Pervasive healthcare support through mobile information technology solutions is playing an increasing role in the attempt to improve healthcare and reduce costs. Despite the apparent attractiveness, many mobile applications have failed or have not been implemented as predicted. Among factors possibly leading to such outcomes, technology adoption is a key problem. This must be investigated early in the development process because healthcare is a particularly sensitive area with vital social implications. Moreover, it is important to investigate technology acceptance using the support of scientific tools validated for relevant information systems research. This article presents an empirical study based on the Technology Acceptance Model 2 in mobile homecare nursing. The study elicited the perceptions of 91 Canadian nurses who used personal digital assistants for 1 month in their daily activities. A partial least squares modeling data analysis revealed that nurse's perception of usefulness is the main factor in the adoption of mobile technology, having subjective norm and image within the organization as significant antecedents. Overall, this study was the first attempt at investigating scientifically, through a pertinent information systems research model, user adoption of mobile systems by homecare nursing personnel.

  11. Classification Accuracy of Mixed Format Tests: A Bi-Factor Item Response Theory Approach.

    Science.gov (United States)

    Wang, Wei; Drasgow, Fritz; Liu, Liwen

    2016-01-01

    Mixed format tests (e.g., a test consisting of multiple-choice [MC] items and constructed response [CR] items) have become increasingly popular. However, the latent structure of item pools consisting of the two formats is still equivocal. Moreover, the implications of this latent structure are unclear: For example, do constructed response items tap reasoning skills that cannot be assessed with multiple choice items? This study explored the dimensionality of mixed format tests by applying bi-factor models to 10 tests of various subjects from the College Board's Advanced Placement (AP) Program and compared the accuracy of scores based on the bi-factor analysis with scores derived from a unidimensional analysis. More importantly, this study focused on a practical and important question-classification accuracy of the overall grade on a mixed format test. Our findings revealed that the degree of multidimensionality resulting from the mixed item format varied from subject to subject, depending on the disattenuated correlation between scores from MC and CR subtests. Moreover, remarkably small decrements in classification accuracy were found for the unidimensional analysis when the disattenuated correlations exceeded 0.90.

  12. A factorization approach to next-to-leading-power threshold logarithms

    Energy Technology Data Exchange (ETDEWEB)

    Bonocore, D. [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); Laenen, E. [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); ITFA, University of Amsterdam,Science Park 904, Amsterdam (Netherlands); ITF, Utrecht University,Leuvenlaan 4, Utrecht (Netherlands); Magnea, L. [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino,Via P. Giuria 1, I-10125, Torino (Italy); Melville, S. [School of Physics and Astronomy, University of Glasgow,Glasgow, G12 8QQ (United Kingdom); Vernazza, L. [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, University of Edinburgh,Edinburgh, EH9 3JZ, Scotland (United Kingdom); White, C.D. [School of Physics and Astronomy, University of Glasgow,Glasgow, G12 8QQ (United Kingdom)

    2015-06-03

    Threshold logarithms become dominant in partonic cross sections when the selected final state forces gluon radiation to be soft or collinear. Such radiation factorizes at the level of scattering amplitudes, and this leads to the resummation of threshold logarithms which appear at leading power in the threshold variable. In this paper, we consider the extension of this factorization to include effects suppressed by a single power of the threshold variable. Building upon the Low-Burnett-Kroll-Del Duca (LBKD) theorem, we propose a decomposition of radiative amplitudes into universal building blocks, which contain all effects ultimately responsible for next-to-leading-power (NLP) threshold logarithms in hadronic cross sections for electroweak annihilation processes. In particular, we provide a NLO evaluation of the radiative jet function, responsible for the interference of next-to-soft and collinear effects in these cross sections. As a test, using our expression for the amplitude, we reproduce all abelian-like NLP threshold logarithms in the NNLO Drell-Yan cross section, including the interplay of real and virtual emissions. Our results are a significant step towards developing a generally applicable resummation formalism for NLP threshold effects, and illustrate the breakdown of next-to-soft theorems for gauge theory amplitudes at loop level.

  13. Identifying niche-mediated regulatory factors of stem cell phenotypic state: a systems biology approach.

    Science.gov (United States)

    Ravichandran, Srikanth; Del Sol, Antonio

    2017-02-01

    Understanding how the cellular niche controls the stem cell phenotype is often hampered due to the complexity of variegated niche composition, its dynamics, and nonlinear stem cell-niche interactions. Here, we propose a systems biology view that considers stem cell-niche interactions as a many-body problem amenable to simplification by the concept of mean field approximation. This enables approximation of the niche effect on stem cells as a constant field that induces sustained activation/inhibition of specific stem cell signaling pathways in all stem cells within heterogeneous populations exhibiting the same phenotype (niche determinants). This view offers a new basis for the development of single cell-based computational approaches for identifying niche determinants, which has potential applications in regenerative medicine and tissue engineering. © 2017 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

  14. "The ickiness factor:" case study of an unconventional psychotherapeutic approach to pediatric OCD.

    Science.gov (United States)

    Dembo, Justine S

    2014-01-01

    Obsessive-compulsive disorder (OCD) is a complex condition with biological, genetic, and psychosocial causes. Traditional evidence-based treatments include cognitive-behavioural therapy, either alone or in combination with serotonin-specific reuptake inhibitors (SSRI's), other serotonergic agents, or atypical antipsychotics. These treatments, however, often do not lead to remission, and therefore, it is crucial to explore other less conventional therapeutic approaches. This paper describes a case study in which psychodynamic, narrative, existential, and metaphor therapy in combination with more conventional treatments led to a dramatic remission of severe OCD in a 12 year old hospitalized on a psychiatric inpatient unit. The paper, which is written partly in the form of a story to demonstrate on a meta-level the power of narrative, is also intended to illustrate the challenges of countertransference in the treatment of patients with severe OCD, and the ways in which a reparative therapeutic alliance can lead to unexpected and vital change.

  15. A systems theory approach to career development: Exploring factors that affect science as a career choice

    Science.gov (United States)

    Liskey, Brian K.

    This research project was designed to examine the factors that affect students' choice in a career. Specifically, the factors of (a) achievement, (b) interest, (c) self-efficacy, (d) perceived preparation for a career, and (e) being informed about a career will be under investigation. Of key importance to the study is how these factors can affect a student's perception about choosing a science career. A quantitative analysis of secondary data from the 2006 and 2009 Program for International Student Assessment (PISA) international assessment and attitudinal questionnaire provided data on student perceptions and aptitude in science. The sample from PISA included over 400,000 15 year-old students from 57 countries. From the 57 countries, 30 countries, comprised by Organization for Economic and Cooperative Development (OECD), were isolated for analysis. Within this group of 30, 11 were selected for comparison based on their questionnaire response to expectations for a career in science at age 30. The Institute for Educational Science's, International Data Explorer was utilized to acquire and analyze data from the 2006 and 2009 PISA international tests and questionnaires to determine significance between scaled scores and PISA indices. Variables were chosen as factors affecting student's perception on various systems outlined by the Systems Theory of Career Development (Patton & McMahon, 1997) and the Systems Theory of Career Development Framework (Patton & McMahon, 1999). Four country groups were established based on student responses to question 30a from the 2006 PISA attitudinal questionnaire, which asks what career students expected to have at age 30. The results from comparing country groups showed that countries in Group A, which showed the highest values for students expecting a career in science, also had the highest average values for achievement on the PISA science literacy assessment. Likewise, countries that had the lowest values for expecting a career in

  16. Diagnostic Testing Approaches for Activated Protein C Resistance and Factor V Leiden: A Comparison of Institutional and National Provider Practices.

    Science.gov (United States)

    Perez Botero, Juliana; Majerus, Julie A; Strege, Ann K; Johnson, Ryan D; Chen, Dong; Pruthi, Rajiv K

    2017-06-01

    To analyze the economic impact of testing for activated protein C resistance (APC-R) due to factor V Leiden (FVL) mutation with APC-R with reflexive FVL genotyping (algorithmic approach) or genotyping alone. OptumLabs Data Warehouse (OLDW) data were used to assess testing approaches. Insurance claims for APC-R and FVL in 2013 were compared with the Mayo Clinic database. Centers for Medicare & Medicaid Services diagnostic fee schedules were used to assign costs. Of 19.3 million OLDW-covered individuals, 74,242 (0.385%) received 75,608 tests: APC-R, 2,265 (2.9%); FVL genotyping, 70,619 (90.1%); and both APC-R and FVL, 2,724 (7.0%). In total, 1,317 tests were performed at Mayo Clinic: APC-R with reflex FVL (1,256; 95.4%) and FVL alone (61; 4.6%). Costs per evaluated individual and per total population (person/year) in OLDW and algorithmic approach were $83.77 vs $36.38 and $0.32 vs $0.14, respectively. The cost-optimized algorithmic approach reduces health care costs. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  17. An approach for improving repeatability and reliability of non-negative matrix factorization for muscle synergy analysis.

    Science.gov (United States)

    Shourijeh, Mohammad S; Flaxman, Teresa E; Benoit, Daniel L

    2016-02-01

    The aim of this study was to evaluate non-negative matrix factorization (NMF) and concatenated NMF (CNMF) to analyze and reliably extract muscle synergies. NMF and CNMF were used to extract knee joint muscle synergies from surface EMGs collected during a weight bearing, force matching task. Repeatability and between subject similarity were evaluated for each method using intra-class correlation coefficients (ICCs). High repeatability was found for CNMF (>0.99; 0.99-1.0) compared to NMF (>0.26; range 0.26-0.98). Reasonable consistency across subjects was improved using the CNMF over the NMF approach. CNMF was found to be a more reliable approach than NMF and suitable for between subject comparison of muscle synergies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Using the Fuzzy Linguistic Preference Relation Approach for Assessing the Importance of Risk Factors in a Software Development Project

    Directory of Open Access Journals (Sweden)

    Shih-Tong Lu

    2013-01-01

    Full Text Available This study employs fuzzy linguistic preference relation (Fuzzy LinPreRa approach to assess the relative degree of impact of risk factors in software development project for two expert groups working in technology enterprises and software development companies. For the identified risk dimensions, the results show the same rankings for these two groups. “Organization function risk” is considered the most important dimension influencing the software development project performance, with the others, in order, being “developing technology risk,” “resources integration risk,” “personnel system risk” and “system requirement risk.” The proposed approach not only facilitates the information collecting for making pairwise comparisons, but it also eliminates the inconsistencies in the collected information.

  19. Where is My Pay? Critical Success Factors of a Payroll System – A System Life Cycle Approach

    Directory of Open Access Journals (Sweden)

    Mohan Thite

    2014-06-01

    Full Text Available Majority of firms deploy technologies in HR administrative applications. While payroll processing is a routine transactional activity, poor design and implementation of payroll system can cause immense harm to employee and organizational well-being. Based on the case study of a flawed payroll system in a large and complex public sector organization in Australia, we highlight the key success factors using the system life cycle approach underpinned by the agile philosophy. It highlights the critical importance of strategic organizational review, user involvement and ongoing communication with diverse stakeholders during the planning, analysis, design, implementation and review stages of a payroll project. It reinforces the need for the adoption of and adherence to sound project and change management methodologies. We also explore the limitations of shared service center approach.

  20. [Application of risk-based approach for determination of critical factors in technology transfer of production of medicinal products].

    Science.gov (United States)

    Beregovykh, V V; Spitskiy, O R

    2014-01-01

    Risk-based approach is used for examination of impact of different factors on quality of medicinal products in technology transfer. A general diagram is offered for risk analysis execution in technology transfer from pharmaceutical development to production. When transferring technology to full- scale commercial production it is necessary to investigate and simulate production process application beforehand in new real conditions. The manufacturing process is the core factorfor risk analysis having the most impact on quality attributes of a medicinal product. Further importantfactors are linked to materials and products to be handled and manufacturing environmental conditions such as premises, equipment and personnel. Usage of risk-based approach in designing of multipurpose production facility of medicinal products is shown where quantitative risk analysis tool RAMM (Risk Analysis and Mitigation Matrix) was applied.

  1. Factors Affecting Malnutrition in Developing Countries: A Linear Mixed Model Approach

    Directory of Open Access Journals (Sweden)

    Sohair F. Higazi

    2012-11-01

    Full Text Available  AbstractThe main objective of this study is to pinpoint the main factors that affect the percentage who suffers of malnutrition in developing countries. Three locations are randomly chosen: Asia, Africa, and Middle east and North Africa ( MENA; A total of 96 countries were chosen randomly from 137  developing countries of the three locations; and were cross classified by " Location" and  " Human Development Index (HDI as high, middle, and low (UNDP,  2005.  Data for the study was compiled from FAO (2005. The analysis started with seven explanatory variables and the dependent variable; however, stepwise regression reveals that the average Protein intake and Infant mortality rate were the only two significant variables. "Location and "HDI" are dummy coded and OLS regression is performed using the two significant variables, but the only significant variable was the "average protein intake". OLS multiple regression Model is re-applied to the data using dummy variables technique with interaction with the "average Protein intake", nine regression equations were reached.The Linear Mixed effect Models are also applied, using "location" as the random factor and "HDI" as the fixed factor. Five models were applied: (1 a null model (baseline modelwhere no predictors are introduced to the model; (2 the fixed model: where predictors used are the  covariate and the HDI; (3 the random model: where predictors used are  the covariate and Location ; (4 the mixed model: where predictors used are the covariate and the HDI I  ( fixed and the location( random; and (5 the random coefficient model: where predictors used are  the covariate ,  the HDI Index  and the location but produces different prediction equations that differ in slopes and intercepts. Models are compared based on information criterions. The random coefficient model produces the least criterion values and thus fits better than all previous ones. A comparison between the Random Coefficient

  2. STABLE DIAMOND GRINDING

    Directory of Open Access Journals (Sweden)

    Yury Gutsalenko

    2010-06-01

    Full Text Available The paper generalizes on the one hand theory of kinematic-geometrical simulation of grinding processes by means of tools with working part as binding matrix with abrasive grains located in it in random manner, for example diamond grains, and on the other hand practical performance of combined grinding process, based on introduction of additional energy as electric discharges and called by the organization-developer (Kharkov Polytechnic Institute «diamond-spark grinding» as applied to processing by means of diamond wheel. Implementation of diamond-spark grinding technologies on the basis of developed generalized theoretical approach allows to use the tool with prescribed tool-life, moreover to make the most efficient use of it up to full exhausting of tool-life, determined by diamond-bearing thickness. Development is directed forward computer-aided manufacturing.

  3. A possible methodological approach to setting up control level of radiation factors

    International Nuclear Information System (INIS)

    Devyatajkin, E.V.; Abramov, Yu.V.

    1986-01-01

    The mathematical formalization of the concept of control levels (CL) which enables one to obtain CL numerical values of controllable parameters required for rapid control purposes is described. The initial data for the assessment of environmental radioactivity are the controllable parameter values that is practical characteristic of controllable radiation factor showing technically measurable or calculation value. The controllable parameters can be divided into two classes depending on the degree of radiation effect on a man: possessing additivity properties (dosimetric class) and non-possessing (radiation class, which comprises the results of control of medium alteration dynamics, equipment operation safety, completeness of protection measures performance). The CL calculation formulas with account for requirements of radiation safety standards (RSS-76) are presented

  4. Climaite - a three factor climate change ecosystem manipulation study: Set up and approaches for data analysis

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Beier, C.; Kappel Schhmidt, I.

    In a new Danish climate change related field scale experiment, CLIMAITE, we are investigating the impacts of individual and multiple simultaneous global changes on ecosystem processes and functioning in a Danish semi natural grassland vegetation dominated by Deschampsia flexuosa and Calluna...... vulgaris. The Climaite experiment involves three global change factors: elevated CO2 (510 ppm), elevated temperature (+ 1-2 C) and altered precipitation (1-1.5 months extended drought in May-July) all compared to ambient conditions in a complete factorial design. The experiment includes six replicates...... initial results from the first treatment year on manipulated and ambient CO2 concentrations and night time temperatures together with plant, soil and ecosystem responses to the treatments (e.g. vegetation surface temperature, soil water content, soil water chemistry, phenology and C sequestration). (www.climaite.dk)...

  5. Regeneration Approaches for Dental Pulp and Periapical Tissues with Growth Factors, Biomaterials, and Laser Irradiation

    Directory of Open Access Journals (Sweden)

    Shizu Hirata

    2011-10-01

    Full Text Available In current dental practice, restorative and endodontic procedures have been developed in an attempt to preserve the vitality of dental pulp after exposure to external stimuli such as caries infection. When damage to dental pulp is reversible, pulp wound healing can proceed, whereas irreversible damage induces pathological changes in dental pulp, eventually requiring its removal. Furthermore, dentists sometimes extract non-vital teeth because of severe caries progression, critical size of periapical lesion, and tooth fracture. To overcome the limitations of presently available therapies, it is important to develop regeneration therapy for dental pulp and periapical tissues. In this review, we focus on the regeneration of dental pulp and periapical tissues by application of exogenous growth factors and scaffolds, as well as low-intensity laser irradiation as an auxiliary therapy for regeneration therapy.

  6. An overview of gambling disorder: from treatment approaches to risk factors

    Science.gov (United States)

    Menchon, José M; Mestre-Bach, Gemma; Steward, Trevor; Fernández-Aranda, Fernando; Jiménez-Murcia, Susana

    2018-01-01

    Gambling disorder (GD) has been reclassified recently into the “Substance-Related and Addictive Disorders” category of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), a landmark occurrence for a behavioral addiction. GD is characterized by recurrent, maladaptive gambling behavior that results in clinically significant distress. Although the number of randomized controlled trials assessing the effectiveness of pharmacological treatments is limited, some pharmacological treatments, notably opiate antagonists, have been employed in the treatment of GD. Patients with GD often present cognitive distortions and specific personality traits, making treatment more difficult. Cognitive behavioral therapy has become the most common psychological intervention for treating gambling problems, and it is effective in reducing gambling behavior. In this brief overview, we provide a report on the state of pharmacological and psychological treatments for gambling disorder. Risk factors and potential future lines of research are addressed.

  7. An overview of gambling disorder: from treatment approaches to risk factors [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    José M Menchon

    2018-04-01

    Full Text Available Gambling disorder (GD has been reclassified recently into the “Substance-Related and Addictive Disorders” category of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5, a landmark occurrence for a behavioral addiction. GD is characterized by recurrent, maladaptive gambling behavior that results in clinically significant distress. Although the number of randomized controlled trials assessing the effectiveness of pharmacological treatments is limited, some pharmacological treatments, notably opiate antagonists, have been employed in the treatment of GD. Patients with GD often present cognitive distortions and specific personality traits, making treatment more difficult. Cognitive behavioral therapy has become the most common psychological intervention for treating gambling problems, and it is effective in reducing gambling behavior. In this brief overview, we provide a report on the state of pharmacological and psychological treatments for gambling disorder. Risk factors and potential future lines of research are addressed.

  8. Identifying environmental risk factors for asthma emergency care" a multilevel approach for ecological study.

    Science.gov (United States)

    Allacci, MaryAnn Sorensen

    2005-01-01

    This ongoing empirical study suggests a model for evaluating a combination of environmental risk factors to explain neighborhood differences in adult use of Harlem Hospital's Asthma Emergency Department services. A multilevel or "nested" model incorporates methods for hypothesis testing using geographic information systems (GIS) and existing data from Harlem Hospital Center, city agencies, and other sources to measure variables on both building and street segment levels. Selection of the best geographic scale by which to measure housing conditions, neighborhood physical quality, income indicators, and access to healthcare is an important strategy toward identifying neighborhood socioenvironmental patterns contributing to geographic clustering of asthma emergencies. Specific community interventions may then be defined to improve the health outcomes of residents with asthma.

  9. Uranium and radium in Finnsjoen - an experimental approach for calculation of transfer factors

    International Nuclear Information System (INIS)

    Evans, S.; Bergman, R.

    1981-01-01

    The radiological safety studies for underground disposal of HLW show that the future individual and collective doses to an important extent may originate from groundwater borne radium and uranium which reach the biosphere. Indications that the dispersion rates presently used give rise to overestimations of calculated doses justified an investigation for more realistic turnover rates of radium and uranium than those which now are in use. Within one of the sites selected for testing, the area around lake Finnsjoen, a small number of environmental samples were collected and analyzed with respect to radium and uranium and the new transfer coefficients between soil and lake water were derived. The dose rates obtained with the new transfer factors show a close agreement for radium and a slight increase for uranium compared with earlier calculations. (Auth.)

  10. Students’ perceptions and attitudes towards statistics in South African university: An exploratory factor analysis approach.

    Directory of Open Access Journals (Sweden)

    Bokang Ncube

    2015-08-01

    Full Text Available The major part of students at institutions of higher learning has shown an aversion for statistics. These attitudes impede on students’ performance. Among factors affecting students’ achievement in the subject is self-efficacy, self-concept, anxiety and low self-perception. In the main, this study sought to explore students’ perceptions and attitudes towards statistics. Data used was collected through SATS-36 and MPSP questionnaires from students who availed themselves for lectures of first year statistics and statistics related courses at a university in South Africa. The findings proved that students’ perceived academic and professional relevance of statistics relates to their statistics proficiency. Students with low statistics self-perception are bound to develop negative attitudes towards the subject. Interest, mathematics and statistics self-efficacy, enjoyment, worth, relevance and effort were identified as precursors of statistics course achievement.

  11. Factors Associated with Mortality and Graft Failure in Liver Transplants: A Hierarchical Approach.

    Directory of Open Access Journals (Sweden)

    Luciana Haddad

    Full Text Available Liver transplantation has received increased attention in the medical field since the 1980s following the introduction of new immunosuppressants and improved surgical techniques. Currently, transplantation is the treatment of choice for patients with end-stage liver disease, and it has been expanded for other indications. Liver transplantation outcomes depend on donor factors, operating conditions, and the disease stage of the recipient. A retrospective cohort was studied to identify mortality and graft failure rates and their associated factors. All adult liver transplants performed in the state of São Paulo, Brazil, between 2006 and 2012 were studied.A hierarchical Poisson multiple regression model was used to analyze factors related to mortality and graft failure in liver transplants. A total of 2,666 patients, 18 years or older, (1,482 males; 1,184 females were investigated. Outcome variables included mortality and graft failure rates, which were grouped into a single binary variable called negative outcome rate. Additionally, donor clinical, laboratory, intensive care, and organ characteristics and recipient clinical data were analyzed. The mortality rate was 16.2 per 100 person-years (py (95% CI: 15.1-17.3, and the graft failure rate was 1.8 per 100 py (95% CI: 1.5-2.2. Thus, the negative outcome rate was 18.0 per 100 py (95% CI: 16.9-19.2. The best risk model demonstrated that recipient creatinine ≥ 2.11 mg/dl [RR = 1.80 (95% CI: 1.56-2.08], total bilirubin ≥ 2.11 mg/dl [RR = 1.48 (95% CI: 1.27-1.72], Na+ ≥ 141.01 mg/dl [RR = 1.70 (95% CI: 1.47-1.97], RNI ≥ 2.71 [RR = 1.64 (95% CI: 1.41-1.90], body surface ≥ 1.98 [RR = 0.81 (95% CI: 0.68-0.97] and donor age ≥ 54 years [RR = 1.28 (95% CI: 1.11-1.48], male gender [RR = 1.19(95% CI: 1.03-1.37], dobutamine use [RR = 0.54 (95% CI: 0.36-0.82] and intubation ≥ 6 days [RR = 1.16 (95% CI: 1.10-1.34] affected the negative outcome rate.The current study confirms that both donor and

  12. Modeling a hierarchical structure of factors influencing exploitation policy for water distribution systems using ISM approach

    Science.gov (United States)

    Jasiulewicz-Kaczmarek, Małgorzata; Wyczółkowski, Ryszard; Gładysiak, Violetta

    2017-12-01

    Water distribution systems are one of the basic elements of contemporary technical infrastructure of urban and rural areas. It is a complex engineering system composed of transmission networks and auxiliary equipment (e.g. controllers, checkouts etc.), scattered territorially over a large area. From the water distribution system operation point of view, its basic features are: functional variability, resulting from the need to adjust the system to temporary fluctuations in demand for water and territorial dispersion. The main research questions are: What external factors should be taken into account when developing an effective water distribution policy? Does the size and nature of the water distribution system significantly affect the exploitation policy implemented? These questions have shaped the objectives of research and the method of research implementation.

  13. Sustainable operations management and benchmarking in brewing: A factor weighting approach

    Directory of Open Access Journals (Sweden)

    Daniel P. Bumblauskas

    2017-06-01

    Full Text Available The brewing industry has been moving towards more efficient use of energy, water reuse and stewardship, and the tracking of greenhouse gas (GHG emissions to better manage environmental and social responsibility. Commercial breweries use a great deal of water and energy to convert one gallon (liter of water into one gallon (liter of beer. An analysis was conducted on sustainable operations and supply chain management at various United States and international breweries, specifically Europe, to benchmark brewery performance and establish common metrics for sustainability in the beer supply chain. The primary research questions explored in this article are whether water reclamation and GHG emissions can be properly monitored and measured and if processes can be created to help control waste (lean and emissions. Additional questions include how we can use operations management strategies and techniques such as the Factor-Weighted Method (FWM in industries such as brewing to develop sustainability scorecards.

  14. Evaluating the Total Factor Productivity Growth in Manufacturing Industries of Iran (Data Envelopment Analysis Approach

    Directory of Open Access Journals (Sweden)

    Vahideh Ahmadi

    2014-01-01

    Full Text Available This paper examines the total factor productivity changes for 23 main manufacturing industries (2-digit ISIC group and country's provinces using data envelopment analysis during 2005 to 2007. The results show 2.3% increase in the productivity of the whole sector (average over the studied period, while the productivity of the country's provinces decreases by 7.3%, in the same period. We find Food and Beverage products and Khuzestan province having the highest productivity growth. Non-optimal allocation of resources and using of old equipments are the most important drawbacks of productivity growth for 23 main ISIC groups and provinces. Finally estimation of the regression models by panel data method reveals the privatization and increasing of labor’s available capital having a significant effect on productivity growth.

  15. Inclusive J/{psi} photoproduction and polarization at HERA in the k{sub T}-factorization approach

    Energy Technology Data Exchange (ETDEWEB)

    Baranov, S.P. [P.N. Lebedev Physics Institute, Moscow (Russian Federation); Lipatov, A.V.; Zotov, N.P. [M.V. Lomonosov Moscow State Univ. (Russian Federation). D.V. Skobeltsyn Institute of Nuclear Physics

    2010-12-15

    We investigate the inclusive photoproduction of J/{psi} mesons at HERA within the framework of the k{sub T} -factorization QCD approach. Our consideration is based on the color singlet model supplemented with the relevant off-shell matrix elements and the CCFM and KMR unintegrated gluon densities in a proton and in a photon. Both the direct and resolved photon contributions are taken into account. Our predictions are compared with the recent experimental data taken by the H1 and ZEUS collaborations. Special attention is put on the J/{psi} polarization parameters {lambda} and {nu} which are sensitive to the production dynamics. (orig.)

  16. An investigation into factors affecting teachers use of ICT in an Irish post primary school : a case approach

    OpenAIRE

    Kent, Elma

    2010-01-01

    non-peer-reviewed Over the past number of years there has been a move towards using ICT. This study explores factors that affect post-primary teachers use of ICT in the teaching and learning environment. The researcher used a case study approach to investigate ICT use in a recently established community school in Ireland. A self-administered questionnaire was issued to all teaching staff (n=70). A random sample of teachers (n=7) were interviewed on their ICT practices and attitudes towards...

  17. WORKSHOP: Stable particle motion

    International Nuclear Information System (INIS)

    Ruggiero, Alessandro G.

    1993-01-01

    Full text: Particle beam stability is crucial to any accelerator or collider, particularly big ones, such as Brookhaven's RHIC heavy ion collider and the larger SSC and LHC proton collider schemes. A workshop on the Stability of Particle Motion in Storage Rings held at Brookhaven in October dealt with the important issue of determining the short- and long-term stability of single particle motion in hadron storage rings and colliders, and explored new methods for ensuring it. In the quest for realistic environments, the imperfections of superconducting magnets and the effects of field modulation and noise were taken into account. The workshop was divided into three study groups: Short-Term Stability in storage rings, including chromatic and geometric effects and correction strategies; Long-Term Stability, including modulation and random noise effects and slow varying effects; and Methods for determining the stability of particle motion. The first two were run in parallel, but the third was attended by everyone. Each group considered analytical, computational and experimental methods, reviewing work done so far, comparing results and approaches and underlining outstanding issues. By resolving conflicts, it was possible to identify problems of common interest. The workshop reaffirmed the validity of methods proposed several years ago. Major breakthroughs have been in the rapid improvement of computer capacity and speed, in the development of more sophisticated mathematical packages, and in the introduction of more powerful analytic approaches. In a typical storage ring, a particle may be required to circulate for about a billion revolutions. While ten years ago it was only possible to predict accurately stability over about a thousand revolutions, it is now possible to predict over as many as one million turns. If this trend continues, in ten years it could become feasible to predict particle stability over the entire storage period. About ninety participants

  18. Individual and contextual factors related to binge drinking among adolescents in Spain: a multilevel approach.

    Science.gov (United States)

    Teixidó-Compañó, Ester; Sordo, Luis; Bosque-Prous, Marina; Puigcorbé, Susanna; Barrio, Gregorio; Brugal, M Teresa; Belza, María José J; Espelt, Albert

    2018-01-15

    The aim of this study was to estimate the prevalence of binge drinking by regions in Spain and assess the effect of individual and contextual factors related to this drinking pattern in adolescents. A cross-sectional study was performed with data from the 2014 Spanish School Survey on Drug Use (ESTUDES) in students aged 14-18 years (N = 34,259). The outcome was binge drinking in adolescents during the last 30 days. Individual independent variables were socioeconomic variables and variables related to access to alcohol and its availability. Contextual variables consisted of adult alcohol consumption, public policies on alcohol, and socioeconomic factors. Multilevel Poisson regression models with robust variance were estimated, obtaining prevalence ratios (PR) and their 95% confidence intervals.  The results showed that the prevalence of youth binge drinking by region of residence was similar for both sexes (r = 0.72). At the individual level, binge drinking was mainly associated with the perception of easy access to alcohol (PR: 1.38; 95% CI: 1.23-1.55), consumption in open areas [(PR: 3.82; 95% CI: 3.44-4.24) < once a month and (PR: 6.57; 95% CI: 5.85-7.37) ≥ once a month], at least one parent allowing alcohol consumption (PR: 1.42; 95% CI: 1.37-1.47), and receiving >30 euros weekly (PR :1.51; 95% CI: 1.37-1.67). Contextual variables were not associated with youth binge drinking when individual variables were considered. In conclusion, youth binge drinking was associated with individual variables related to high alcohol accessibility and availability, regardless of contextual variables. These variables explained the variability in binge drinking among Spanish regions.

  19. Weld Magnification Factor Approach in Cruciform Joints Considering Post Welding Cooling Medium and Weld Size

    Directory of Open Access Journals (Sweden)

    Oscar Araque

    2018-01-01

    Full Text Available The objective of this research is to develop an experimental-theoretical analysis about the influence of the cooling medium and the geometry of the welding bead profile in fatigue life and the associated parameters with structural integrity of welded joints. A welded joint with cruciform geometry is considered using SMAW (Shielded Metal ArcWelding, plates in structural steel ASTM A36 HR of 8 mm of thickness, and E6013 electrode input. A three-dimensional computational model of the cruciform joint was created using the finite element method. For this model, the surface undulation of the cord and differentiation in the mechanical properties of the fusion zone were considered, the heat-affected zone (HAZ and base material, respectively. In addition, an initial residual stress field, which was established experimentally, was considered. The results were a set of analytical expressions for the weld magnification factor Mk. It was found that values for the latter decrease markedly in function of the intensity of the cooling medium used in the post welding cooling phase, mainly due to the effect of the residual compressive stresses. The obtained models of behavior of the weld magnification factor are compared with the results from other researchers with some small differences, mainly due to the inclusion of the cooling effect of the post weld and the variation of the leg of the weld bead. The obtained analytical equations in the present research for Mk can be used in management models of life and structural integrity for this type of welded joint.

  20. Using a Systematic Approach to Identifying Organizational Factors in Root Cause Analysis

    International Nuclear Information System (INIS)

    Gallogly, Kay Wilde

    2011-01-01

    This presentation set the scene for the second discussion session. In her presentation, the author observed that: - Investigators do not see the connection between the analysis tools available and the identification of HOF. Most investigators use the tools in a cursory manner and so do not derive the full benefits of the tools. Some tools are used for presentation purposes as opposed to being used for analytical purposes e.g. event and causal factors charts. In some cases, the report will indicate that specific analytical tools were used in the investigation but the analysis is not in the body of the report. - Some investigators are documenting HOF causes but do not recognize them as such. This indicates a lack of understanding of HOF. - Others investigators focus on technical issues because of their own comfort level. - The culture of the Organisation will affect the depth of the investigation and therefore the use of the analytical tools to pursue HOF issues. - The author contends that if analysis tools are applied systematically to gather factually based data, then HOF issues can be identified. The use of factual information (without judgement and subjectivity) is important to maintain the credibility of the investigation especially when HOF issues are identified. - Systematic use of tools assists in better communication of the issues to foster greater understanding and acceptance by senior management. - Barrier Analysis, Change Analysis, and TWIN (Task Demands, Work Environment, Individual Capabilities, and Human Nature) all offer the opportunity to identify HOF issues if the analyst pursues this line of investigation. It was illustrated that many elements of the TWIN Error Precursors are themselves Organisational in nature. - The TWIN model applied to the Anatomy of an Event will help to distinguish those which are Organisational issues (Latent Organisational Weaknesses, Error Precursors and Flawed Defences) and those which are human factors (Active Errors

  1. Factors affecting pharmacy engagement and pharmacy customer devotion in community pharmacy: A structural equation modeling approach.

    Science.gov (United States)

    Nitadpakorn, Sujin; Farris, Karen B; Kittisopee, Tanattha

    2017-01-01

    The concept of customer engagement and devotion has been applied in various service businesses to keep the customers with business However, a limited number of studies were performed to examine the context of customer engagement and devotion in pharmacy business which focus on the impact of customer perceptions about pharmacists, perceived quality of pharmacy structure, medication price strategy on pharmacy engagement and pharmacy customer devotion in a pharmacy providing pharmaceutical care to the customers. This study aimed to assess a conceptual model depicting the relationships among customer perceptions about pharmacists, pharmacy quality structure, medication price, customer engagement, and customer devotion. And also aimed to assess and measure if there is a direct or indirect relationship between these factors. A quantitative study was conducted by using self-administered questionnaires. Two hundred and fifty three customers who regularly visited the pharmacy were randomly recruited from a purposively selected 30 community pharmacies in Bangkok. The survey was completed during February to April 2016. A structural equation model (SEM) was used to assess the direct and indirect relationships between constructs. A total of 253/300 questionnaires were returned for analysis, and the response rate was 84%. Only perceptions about pharmacist in customers receiving professional pharmacy services was statically significant regarding relationship with pharmacy engagement (beta=0.45). Concurrently, the model from empirical data fit with the hypothetical model (p-value = 0.06, adjusted chi-square (CMIN/DF)=1.16, Goodness of Fit Index (GFI)=0.93, Comparatively Fit Index (CFI)=0.99, and Root Mean Square Error Approximation (RMSEA)=0.03). The study confirmed the indirect positive influence of customer perceptions about pharmacist on pharmacy customer devotion in providing pharmacy services via pharmacy engagement It was customer perceptions about pharmacist that influenced

  2. Which Factors Affect the Hospital Re-admission After Treatment Approaches to Urethral Strictures?

    Directory of Open Access Journals (Sweden)

    Reha Girgin

    2017-12-01

    Full Text Available Objective: To investigate patient- and procedure-related factors associated with hospital re-admission following urethral manipulations for the treatment of urethral strictures. Materials and Methods: Data of patients who underwent dilation or internal urethrotomy for urethral strictures between 2011 and 2016 were retrospectively analyzed. Patients who were admitted to our institute for any reason within one month after hospital discharge were evaluated. The patient- and procedure-related factors affecting the readmission rates were revealed by multiple binary logistic regression using stepwise backward elinimination. Results: The average age of 76 male patients was 61.7±14.4 years. The mean maximal flow rate at preoperative uroflowmetry was 6.01±4.3 and the median American Society of Anesthesiologists score was 2.38. The process was the first for 45 (59.2% patients, the second for 16 (21.1% patients, the third for 9 (11.8% patients, and the fourth for 6 (7.9% patients. Amplatz dilators, cold knife and Ho:YAG laser were used in 50%, 27.6% and 22.4% of patients, respectively. The mean length of hospital stay was 0.89±0.31 days, and the complication rate was 19.7% (15/76. The mean urethral catheter dwell time was 8.9±14.2 day. Overall, the procedure was successful in 61 (80.3% patients and failed (Qmax <15 mL/sec in 19.7% of the cases. Fifteen (19.7% patients were re-admitted, while 2 (2.6% patients among them were re-hospitalized for further treatment. Comorbidity and age were independent predictors of re-admission. Conclusion: We found that younger age and lower comorbidities predicted hospital re-admission following procedures for urethral strictures.

  3. A belief-based evolutionarily stable strategy

    OpenAIRE

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-01-01

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed st...

  4. A metabolomics approach to identify factors influencing glucosinolate thermal degradation rates in Brassica vegetables.

    Science.gov (United States)

    Hennig, K; de Vos, R C H; Maliepaard, C; Dekker, M; Verkerk, R; Bonnema, G

    2014-07-15

    Thermal processing of Brassica vegetables can lead to substantial loss of potential health-promoting glucosinolates (GLs). The extent of thermal degradation of a specific GL varies in different vegetables, possibly due to differences in the composition of other metabolites within the plant matrices. An untargeted metabolomics approach followed by random forest regression was applied to identify metabolites associated to thermal GL degradation in a segregating Brassica oleracea population. Out of 413 metabolites, 15 were associated with the degradation of glucobrassicin, six with that of glucoraphanin and two with both GLs. Among these 23 metabolites three were identified as flavonols (one kaempferol- and two quercetin-derivatives) and two as other GLs (4-methoxyglucobrassicin, gluconasturtiin). Twenty quantitative trait loci (QTLs) for these metabolites, which were associated with glucoraphanin and glucobrassicin degradation, were identified on linkage groups C01, C07 and C09. Two flavonols mapped on linkage groups C07 and C09 and co-localise with the QTL for GL degradation determined previously. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Examining the relationship between service quality and customer satisfaction: A factor specific approach

    Directory of Open Access Journals (Sweden)

    Azman Ismail

    2013-06-01

    Full Text Available Purpose: This research was aimed at examining the relationship between service quality and customer satisfaction with data obtained from Malaysian soldiers who were involved in peace keeping missions in a Middle Eastern country. The results of which would enable the management to improve the quality of service accorded to peacekeeping personnel. Design/methodology/approach: The study employed a cross-sectional research design which allowed the researchers to integrate the service quality literature, the semi structured interview and the actual survey to collect and examine the data for optimum results. Findings and Originality/value: The outcome of multiple regression analysis showed that responsiveness and assurance variables reflected a high correlation with customer satisfaction. On the other hand, tangibility, reliability and empathy variables recorded an insignificant correlation with customer satisfaction. Research limitations/implications: With respect to practical contributions, the findings of this study can be used as a guideline by the management to improve the quality of peacekeeping in areas of conflict. Practical implications: For security reasons, certain information affecting customer satisfaction could not be examined in detail. Originality/value: This paper presents key results on service quality and customers satisfaction research by looking at the niche segment which was not previously studied from the Malaysian perspective.

  6. On determinant representations of scalar products and form factors in the SoV approach: the XXX case

    Science.gov (United States)

    Kitanine, N.; Maillet, J. M.; Niccoli, G.; Terras, V.

    2016-03-01

    In the present article we study the form factors of quantum integrable lattice models solvable by the separation of variables (SoVs) method. It was recently shown that these models admit universal determinant representations for the scalar products of the so-called separate states (a class which includes in particular all the eigenstates of the transfer matrix). These results permit to obtain simple expressions for the matrix elements of local operators (form factors). However, these representations have been obtained up to now only for the completely inhomogeneous versions of the lattice models considered. In this article we give a simple algebraic procedure to rewrite the scalar products (and hence the form factors) for the SoV related models as Izergin or Slavnov type determinants. This new form leads to simple expressions for the form factors in the homogeneous and thermodynamic limits. To make the presentation of our method clear, we have chosen to explain it first for the simple case of the XXX Heisenberg chain with anti-periodic boundary conditions. We would nevertheless like to stress that the approach presented in this article applies as well to a wide range of models solved in the SoV framework.

  7. On determinant representations of scalar products and form factors in the SoV approach: the XXX case

    International Nuclear Information System (INIS)

    Kitanine, N; Maillet, J M; Niccoli, G; Terras, V

    2016-01-01

    In the present article we study the form factors of quantum integrable lattice models solvable by the separation of variables (SoVs) method. It was recently shown that these models admit universal determinant representations for the scalar products of the so-called separate states (a class which includes in particular all the eigenstates of the transfer matrix). These results permit to obtain simple expressions for the matrix elements of local operators (form factors). However, these representations have been obtained up to now only for the completely inhomogeneous versions of the lattice models considered. In this article we give a simple algebraic procedure to rewrite the scalar products (and hence the form factors) for the SoV related models as Izergin or Slavnov type determinants. This new form leads to simple expressions for the form factors in the homogeneous and thermodynamic limits. To make the presentation of our method clear, we have chosen to explain it first for the simple case of the XXX Heisenberg chain with anti-periodic boundary conditions. We would nevertheless like to stress that the approach presented in this article applies as well to a wide range of models solved in the SoV framework. (paper)

  8. Familial risk factors in social anxiety disorder: calling for a family-oriented approach for targeted prevention and early intervention.

    Science.gov (United States)

    Knappe, Susanne; Beesdo-Baum, Katja; Wittchen, Hans-Ulrich

    2010-12-01

    Within the last decade, social anxiety disorder (SAD) has been identified as a highly prevalent and burdensome disorder. Both the characterization of its symptomatology and effective treatment options are widely documented. Studies particularly indicate that SAD aggregates in families and has its onset in early adolescence. Given the family as an important context for children's cognitive, emotional and behavioural development, familial risk factors could be expected to significantly contribute to the reliable detection of populations at risk for SAD. Reviewing studies on familial risk factors for SAD argues for the importance of parental psychopathology and unfavourable family environment, but also denotes to several shortcomings such as cross-sectional designs, short follow-up periods, diverging methodologies and the focus on isolated factors. Using a prospective longitudinal study that covers the high-risk period for SAD, including a broader spectrum of putative risk factors may help to overcome many of the methodological limitations. This review sets out to develop a more family-oriented approach for predicting the onset and maintenance of SAD that may be fruitful to derive targeted prevention and early intervention in SAD.

  9. Factors affecting pharmacy engagement and pharmacy customer devotion in community pharmacy: A structural equation modeling approach

    Science.gov (United States)

    Nitadpakorn, Sujin; Kittisopee, Tanattha

    2017-01-01

    Background: The concept of customer engagement and devotion has been applied in various service businesses to keep the customers with business However, a limited number of studies were performed to examine the context of customer engagement and devotion in pharmacy business which focus on the impact of customer perceptions about pharmacists, perceived quality of pharmacy structure, medication price strategy on pharmacy engagement and pharmacy customer devotion in a pharmacy providing pharmaceutical care to the customers. Objective: This study aimed to assess a conceptual model depicting the relationships among customer perceptions about pharmacists, pharmacy quality structure, medication price, customer engagement, and customer devotion. And also aimed to assess and measure if there is a direct or indirect relationship between these factors. Methods: A quantitative study was conducted by using self-administered questionnaires. Two hundred and fifty three customers who regularly visited the pharmacy were randomly recruited from a purposively selected 30 community pharmacies in Bangkok. The survey was completed during February to April 2016. A structural equation model (SEM) was used to assess the direct and indirect relationships between constructs. Results: A total of 253/300 questionnaires were returned for analysis, and the response rate was 84%. Only perceptions about pharmacist in customers receiving professional pharmacy services was statically significant regarding relationship with pharmacy engagement (beta=0.45). Concurrently, the model from empirical data fit with the hypothetical model (p-value = 0.06, adjusted chi-square (CMIN/DF)=1.16, Goodness of Fit Index (GFI)=0.93, Comparatively Fit Index (CFI)=0.99, and Root Mean Square Error Approximation (RMSEA)=0.03). Conclusion: The study confirmed the indirect positive influence of customer perceptions about pharmacist on pharmacy customer devotion in providing pharmacy services via pharmacy engagement It was

  10. Factors affecting pharmacy engagement and pharmacy customer devotion in community pharmacy: A structural equation modeling approach

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    Nitadpakorn S

    2017-09-01

    Full Text Available Background: The concept of customer engagement and devotion has been applied in various service businesses to keep the customers with business However, a limited number of studies were performed to examine the context of customer engagement and devotion in pharmacy business which focus on the impact of customer perceptions about pharmacists, perceived quality of pharmacy structure, medication price strategy on pharmacy engagement and pharmacy customer devotion in a pharmacy providing pharmaceutical care to the customers. Objective: This study aimed to assess a conceptual model depicting the relationships among customer perceptions about pharmacists, pharmacy quality structure, medication price, customer engagement, and customer devotion. And also aimed to assess and measure if there is a direct or indirect relationship between these factors. Methods: A quantitative study was conducted by using self-administered questionnaires. Two hundred and fifty three customers who regularly visited the pharmacy were randomly recruited from a purposively selected 30 community pharmacies in Bangkok. The survey was completed during February to April 2016. A structural equation model (SEM was used to assess the direct and indirect relationships between constructs. Results: A total of 253/300 questionnaires were returned for analysis, and the response rate was 84%. Only perceptions about pharmacist in customers receiving professional pharmacy services was statically significant regarding relationship with pharmacy engagement (beta=0.45. Concurrently, the model from empirical data fit with the hypothetical model (p-value = 0.06, adjusted chi-square (CMIN/DF=1.16, Goodness of Fit Index (GFI=0.93, Comparatively Fit Index (CFI=0.99, and Root Mean Square Error Approximation (RMSEA=0.03. Conclusion: The study confirmed the indirect positive influence of customer perceptions about pharmacist on pharmacy customer devotion in providing pharmacy services via pharmacy

  11. Functional Characterization of Tea (Camellia sinensis MYB4a Transcription Factor Using an Integrative Approach

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    Mingzhuo Li

    2017-06-01

    Full Text Available Green tea (Camellia sinensis, Cs abundantly produces a diverse array of phenylpropanoid compounds benefiting human health. To date, the regulation of the phenylpropanoid biosynthesis in tea remains to be investigated. Here, we report a cDNA isolated from leaf tissues, which encodes a R2R3-MYB transcription factor. Amino acid sequence alignment and phylogenetic analysis indicate that it is a member of the MYB4-subgroup and named as CsMYB4a. Transcriptional and metabolic analyses show that the expression profile of CsMYB4a is negatively correlated to the accumulation of six flavan-3-ols and other phenolic acids. GFP fusion analysis shows CsMYB4a’s localization in the nucleus. Promoters of five tea phenylpropanoid pathway genes are isolated and characterized to contain four types of AC-elements, which are targets of MYB4 members. Interaction of CsMYB4a and five promoters shows that CsMYB4a decreases all five promoters’ activity. To further characterize its function, CsMYB4a is overexpressed in tobacco plants. The resulting transgenic plants show dwarf, shrinking and yellowish leaf, and early senescence phenotypes. A further genome-wide transcriptomic analysis reveals that the expression levels of 20 tobacco genes involved in the shikimate and the phenylpropanoid pathways are significantly downregulated in transgenic tobacco plants. UPLC-MS and HPLC based metabolic profiling reveals significant reduction of total lignin content, rutin, chlorogenic acid, and phenylalanine in CsMYB4a transgenic tobacco plants. Promoter sequence analysis of the 20 tobacco genes characterizes four types of AC-elements. Further CsMYB4a-AC element and CsMYB4a-promoter interaction analyses indicate that the negative regulation of CsMYB4a on the shikimate and phenylpropanoid pathways in tobacco is via reducing promoter activity. Taken together, all data indicate that CsMYB4a negatively regulates the phenylpropanoid and shikimate pathways.Highlight: A tea (Camellia

  12. [Factors associated with the quality of prenatal care: an approach to premature birth].

    Science.gov (United States)

    Melo, Emiliana Cristina; Oliveira, Rosana Rosseto de; Mathias, Thais Aidar de Freitas

    2015-08-01

    To assess the quality of prenatal care in mothers with premature and term births and identify maternal and gestational factors associated with inadequate prenatal care. Cross-sectional study collecting data with the pregnant card, hospital records and interviews with mothers living in Maringa-PR. Data were collected from 576 mothers and their born alive infants who were attended in the public service from October 2013 to February 2014, using three different evaluation criteria. The association of prenatal care quality with prematurity was performed by univariate analysis and occurred only at Kessner criteria (CI=1.79;8.02). The indicators that contributed most to the inadequacy of prenatal care were tests of hemoglobin, urine, and fetal presentation. After logistic regression analysis, maternal and gestational variables associated to inadequate prenatal care were combined prenatal (CI=2.93;11.09), non-white skin color (CI=1.11;2.51); unplanned pregnancy (CI=1.34;3.17) and multiparity (CI=1.17;4.03). Prenatal care must follow the minimum recommended protocols, more attention is required to black and brown women, multiparous and with unplanned pregnancies to prevent preterm birth and maternal and child morbimortality.

  13. Key Factors Affecting the Price of Airbnb Listings: A Geographically Weighted Approach

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    Zhihua Zhang

    2017-09-01

    Full Text Available Airbnb has been increasingly gaining popularity since 2008 due to its low prices and direct interactions with the local community. This paper employed a general linear model (GLM and a geographically weighted regression (GWR model to identify the key factors affecting Airbnb listing prices using data sets of 794 samples of Airbnb listings of business units in Metro Nashville, Tennessee. The results showed that the GWR model performs better than the GLM in terms of accuracy and affected variable selections. Statistically significant differences varied across regions in Metro Nashville. The coefficients illustrate a decreasing trend while there is an increase in the distance from the listed units to the convention center, which indicates that Airbnb listing prices are more sensitive to the distance from the convention center in the central area than in other areas. These findings can also provide implications for stakeholders such as Airbnb hosts to gain a better understanding of the market situation and formulate a suitable pricing strategy.

  14. An alternative approach for evaluating the phenotypic virulence factors of pathogenic Escherichia coli

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    Kamelia M. Osman

    2018-02-01

    Full Text Available Escherichia coli is a recognized zoonotic food-borne pathogen; however, the use of polymerase chain reaction (PCR in the underdeveloped countries to differentiate pathogenic from non-pathogenic E. coli is a problematic issue. Our grail was to assess the phenotypic virulence markers motility, hemolysin, congo red agar, embryo lethality assay and serum resistance for pathogenic E. coli (PEC correlated to PCR tests which is currently used world-wide to evaluate the PEC. The 448 strains of Escherichia coli that were isolated from different sources, were characterized for phenotypic virulence factors such as motility, hemolysin, Congo red binding, Embryo Lethality assay (ELA and serum resistance, as well as antibiotic susceptibility using disc diffusion method to 23 antibiotics. Results exhibited 100% motility and Congo red binding, 97.1% for hemolysin production and 90.2% in the ELA. As a result, we were able to hypothetically conclude that the aforementioned virulence markers are plain, straightforward, economical, rapid, more dynamic, uncomplicated methodology, duplicatable and cost next to nothing when compared to the molecular PCR. Their implementation in a diagnostic microbiology laboratory for vetting is a rewarding task in the underdeveloped countries. It augments endeavors to minimize the use of PCR in our investigations especially during epidemiological and outbreak investigations of PEC.

  15. Factors associated with the quality of prenatal care: an approach to premature birth

    Directory of Open Access Journals (Sweden)

    Emiliana Cristina Melo

    2015-08-01

    Full Text Available OBJECTIVETo assess the quality of prenatal care in mothers with premature and term births and identify maternal and gestational factors associated with inadequate prenatal care.METHODCross-sectional study collecting data with the pregnant card, hospital records and interviews with mothers living in Maringa-PR. Data were collected from 576 mothers and their born alive infants who were attended in the public service from October 2013 to February 2014, using three different evaluation criteria. The association of prenatal care quality with prematurity was performed by univariate analysis and occurred only at Kessner criteria (CI=1.79;8.02.RESULTSThe indicators that contributed most to the inadequacy of prenatal care were tests of hemoglobin, urine, and fetal presentation. After logistic regression analysis, maternal and gestational variables associated to inadequate prenatal care were combined prenatal (CI=2.93;11.09, non-white skin color (CI=1.11;2.51; unplanned pregnancy (CI=1.34;3.17 and multiparity (CI=1.17;4.03.CONCLUSIONPrenatal care must follow the minimum recommended protocols, more attention is required to black and brown women, multiparous and with unplanned pregnancies to prevent preterm birth and maternal and child morbimortality.

  16. A New Displacement-based Approach to Calculate Stress Intensity Factors With the Boundary Element Method

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    Marco Gonzalez

    Full Text Available Abstract The analysis of cracked brittle mechanical components considering linear elastic fracture mechanics is usually reduced to the evaluation of stress intensity factors (SIFs. The SIF calculation can be carried out experimentally, theoretically or numerically. Each methodology has its own advantages but the use of numerical methods has become very popular. Several schemes for numerical SIF calculations have been developed, the J-integral method being one of the most widely used because of its energy-like formulation. Additionally, some variations of the J-integral method, such as displacement-based methods, are also becoming popular due to their simplicity. In this work, a simple displacement-based scheme is proposed to calculate SIFs, and its performance is compared with contour integrals. These schemes are all implemented with the Boundary Element Method (BEM in order to exploit its advantages in crack growth modelling. Some simple examples are solved with the BEM and the calculated SIF values are compared against available solutions, showing good agreement between the different schemes.

  17. Identifying Associations Between Brain Imaging Phenotypes and Genetic Factors via A Novel Structured SCCA Approach.

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    Du, Lei; Zhang, Tuo; Liu, Kefei; Yan, Jingwen; Yao, Xiaohui; Risacher, Shannon L; Saykin, Andrew J; Han, Junwei; Guo, Lei; Shen, Li

    2017-06-01

    Brain imaging genetics attracts more and more attention since it can reveal associations between genetic factors and the structures or functions of human brain. Sparse canonical correlation analysis (SCCA) is a powerful bi-multivariate association identification technique in imaging genetics. There have been many SCCA methods which could capture different types of structured imaging genetic relationships. These methods either use the group lasso to recover the group structure, or employ the graph/network guided fused lasso to find out the network structure. However, the group lasso methods have limitation in generalization because of the incomplete or unavailable prior knowledge in real world. The graph/network guided methods are sensitive to the sign of the sample correlation which may be incorrectly estimated. We introduce a new SCCA model using a novel graph guided pairwise group lasso penalty, and propose an efficient optimization algorithm. The proposed method has a strong upper bound for the grouping effect for both positively and negatively correlated variables. We show that our method performs better than or equally to two state-of-the-art SCCA methods on both synthetic and real neuroimaging genetics data. In particular, our method identifies stronger canonical correlations and captures better canonical loading profiles, showing its promise for revealing biologically meaningful imaging genetic associations.

  18. Wayfinding: a quality factor in human design approach to healthcare facilities.

    Science.gov (United States)

    Del Nord, R

    1999-01-01

    The specific aim of this paper is the systematic analysis of interactions and reciprocal conditions existing between the physical space of hospital buildings and the different categories of individuals that come in contact with them. The physical and environmental facilities of hospital architecture often influence the therapeutic character of space and the employees. If the values of the individual are to be safeguarded in this context, priority needs to be given to such factors as communication, privacy, etc. This would mean the involvement of other professional groups such as psychologists, sociologists, ergonomists, etc. at the hospital building planning stage. This paper will outline the result of some research conducted at the University Research Center "TESIS" of Florence to provide better understanding of design strategies applied to reduce the pathology of spaces within the healthcare environment. The case studies will highlight the parameters and the possible architectural solutions to wayfinding and the humanization of spaces, with particular emphasis on lay-outs, technologies, furniture and finishing design.

  19. General practitioners' views on key factors affecting their desired income: A principal component analysis approach.

    Science.gov (United States)

    Bayati, Mohsen; Rashidian, Arash; Akbari Sari, Ali; Emamgholipour, Sara

    2017-01-01

    Background: Based on the target income hypothesis, the economic behavior of physicians is mainly affected by their target income. This study aimed at designing an instrument to explain how general practitioners (GPs) set their desired income. Methods: A self-administered questionnaire of affecting factors on GPs' target income was extracted from literature reviews and a small qualitative study. Respondents were 666 GPs who completed the questionnaire (response rate= 52%) during 2 seasonal congresses of Iranian GPs. The principal component analysis (PCA) with varimax rotation was used to classify the variables and data reduction. Sample adequacy test, sphericity test, eigenvalues of components, and scree plot were evaluated for PCA. Cronbach's alpha was also checked to assess the internal consistency of the principal components. Results: The results of the KMO measure of sampling adequacy (0.657) and Bartlett's test of sphericity (809.05, pluxury services were selected, which explained 65.19% of the total variance. Finally, only those with a Cronbach's alpha value higher than 0.6 were considered reliable (the first 4 components). Conclusion: Based on the target income hypothesis, a physician's desired level of income affects their behavior. Our developed instrument and its mentioned components can be used in future studies related to GPs' behavior, especially those studies related to the economic aspects of GPs' behavior. It also helps formulate a better payment mechanism for primary care providers.

  20. Factors Contributing to Residential Vacancy and Some Approaches to Management in Gyeonggi Province, Korea

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    Jeehyun Nam

    2016-04-01

    Full Text Available With the decrease in the demand for large-scale apartments as a result of an aging society and a decrease in population, there has been an increase in vacant houses due to a supply that exceeds the projected demands. As a method of urban regeneration in rural areas and activation of citizen communities, the utilization of vacant houses has become one of the ways to promote a new lifestyle, active movement for citizen participation, and business model for long-term revitalization. This study aims to uncover and examine the major causes and factors behind the upswing in vacant houses. We investigated the current state of vacant houses, the recent policies concerning them, and the types of vacant houses in Korea’s Gyeonggi province. We then categorized and analyzed the causes of houses being vacant, their types, and the methods of utilizing them under different local conditions in order to understand the efficient processes and strategies for their utilization. The results showed that an excess of building construction (especially recent construction permits, the number of recipients of the national basic livelihood scheme, and the number of elderly people showed the strongest correlation with vacant houses.