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Sample records for factor structure underlying

  1. Factor structure underlying components of allostatic load.

    Directory of Open Access Journals (Sweden)

    Jeanne M McCaffery

    Full Text Available Allostatic load is a commonly used metric of health risk based on the hypothesis that recurrent exposure to environmental demands (e.g., stress engenders a progressive dysregulation of multiple physiological systems. Prominent indicators of response to environmental challenges, such as stress-related hormones, sympatho-vagal balance, or inflammatory cytokines, comprise primary allostatic mediators. Secondary mediators reflect ensuing biological alterations that accumulate over time and confer risk for clinical disease but overlap substantially with a second metric of health risk, the metabolic syndrome. Whether allostatic load mediators covary and thus warrant treatment as a unitary construct remains to be established and, in particular, the relation of allostatic load parameters to the metabolic syndrome requires elucidation. Here, we employ confirmatory factor analysis to test: 1 whether a single common factor underlies variation in physiological systems associated with allostatic load; and 2 whether allostatic load parameters continue to load on a single common factor if a second factor representing the metabolic syndrome is also modeled. Participants were 645 adults from Allegheny County, PA (30-54 years old, 82% non-Hispanic white, 52% female who were free of confounding medications. Model fitting supported a single, second-order factor underlying variance in the allostatic load components available in this study (metabolic, inflammatory and vagal measures. Further, this common factor reflecting covariation among allostatic load components persisted when a latent factor representing metabolic syndrome facets was conjointly modeled. Overall, this study provides novel evidence that the modeled allostatic load components do share common variance as hypothesized. Moreover, the common variance suggests the existence of statistical coherence above and beyond that attributable to the metabolic syndrome.

  2. The factor structure underlying three self-report multicultural counseling competence scales.

    Science.gov (United States)

    Constantine, Madonna G; Gloria, Alberta M; Ladany, Nicholas

    2002-11-01

    This study examined the extent to which 3 self-report multicultural scales were measuring the predominant 3-factor conceptualization of multicultural counseling competence as consisting of multicultural attitudes/beliefs, knowledge, and skills. Results of a confirmatory factor analysis revealed that the 3-factor model was not fully supported. An exploratory factor analysis identified a 2-factor structure (i.e., self-perceived multicultural counseling skills and multicultural counseling attitudes/beliefs) underlying these instruments. Implications of the findings for clinical practice, training, and research are discussed.

  3. Identification of the underlying factor structure of the Derriford Appearance Scale 24.

    Science.gov (United States)

    Moss, Timothy P; Lawson, Victoria; White, Paul

    2015-01-01

    Background. The Derriford Appearance Scale24 (DAS24) is a widely used measure of distress and dysfunction in relation to self-consciousness of appearance. It has been used in clinical and research settings, and translated into numerous European and Asian languages. Hitherto, no study has conducted an analysis to determine the underlying factor structure of the scale. Methods. A large (n = 1,265) sample of community and hospital patients with a visible difference were recruited face to face or by post, and completed the DAS24. Results. A two factor solution was generated. An evaluation of the congruence of the factor solutions on each of the the hospital and the community samples using Tucker's Coefficient of Congruence (rc = .979) and confirmatory factor analysis, which demonstrated a consistent factor structure. A main factor, general self consciousness (GSC), was represented by 18 items. Six items comprised a second factor, sexual and body self-consciousness (SBSC). The SBSC scale demonstrated greater sensitivity and specificity in identifying distress for sexually significant areas of the body. Discussion. The factor structure of the DAS24 facilitates a more nuanced interpretation of scores using this scale. Two conceptually and statistically coherent sub-scales were identified. The SBSC sub-scale offers a means of identifying distress and dysfunction around sexually significant areas of the body not previously possible with this scale.

  4. Identification of the underlying factor structure of the Derriford Appearance Scale 24

    Directory of Open Access Journals (Sweden)

    Timothy P. Moss

    2015-07-01

    Full Text Available Background. The Derriford Appearance Scale24 (DAS24 is a widely used measure of distress and dysfunction in relation to self-consciousness of appearance. It has been used in clinical and research settings, and translated into numerous European and Asian languages. Hitherto, no study has conducted an analysis to determine the underlying factor structure of the scale.Methods. A large (n = 1,265 sample of community and hospital patients with a visible difference were recruited face to face or by post, and completed the DAS24.Results. A two factor solution was generated. An evaluation of the congruence of the factor solutions on each of the the hospital and the community samples using Tucker’s Coefficient of Congruence (rc = .979 and confirmatory factor analysis, which demonstrated a consistent factor structure. A main factor, general self consciousness (GSC, was represented by 18 items. Six items comprised a second factor, sexual and body self-consciousness (SBSC. The SBSC scale demonstrated greater sensitivity and specificity in identifying distress for sexually significant areas of the body.Discussion. The factor structure of the DAS24 facilitates a more nuanced interpretation of scores using this scale. Two conceptually and statistically coherent sub-scales were identified. The SBSC sub-scale offers a means of identifying distress and dysfunction around sexually significant areas of the body not previously possible with this scale.

  5. Models and Strategies for Factor Mixture Analysis: An Example Concerning the Structure Underlying Psychological Disorders

    Science.gov (United States)

    Clark, Shaunna L.; Muthén, Bengt; Kaprio, Jaakko; D’Onofrio, Brian M.; Viken, Richard; Rose, Richard J.

    2013-01-01

    The factor mixture model (FMM) uses a hybrid of both categorical and continuous latent variables. The FMM is a good model for the underlying structure of psychopathology because the use of both categorical and continuous latent variables allows the structure to be simultaneously categorical and dimensional. This is useful because both diagnostic class membership and the range of severity within and across diagnostic classes can be modeled concurrently. While the conceptualization of the FMM has been explained in the literature, the use of the FMM is still not prevalent. One reason is that there is little research about how such models should be applied in practice and, once a well fitting model is obtained, how it should be interpreted. In this paper, the FMM will be explored by studying a real data example on conduct disorder. By exploring this example, this paper aims to explain the different formulations of the FMM, the various steps in building a FMM, as well as how to decide between a FMM and alternative models. PMID:24302849

  6. Shell structure underlying the evolution of quadrupole collectivity in S-38 and S-40 probed by transient-field g-factor measurements on fast radioactive beams

    CERN Document Server

    Stuchbery, A E; Brown, B A; Campbell, C M; Cook, J M; Davidson, P M; Davies, A D; Dinca, D C; Gade, A; Liddick, S N; Mantica, P F; Mertzimekis, T J; Müller, W F; Terry, J R; Tomlin, B E; Wilson, A N; Yoneda, K; Zwahlen, H

    2006-01-01

    The shell structure underlying shape changes in neutron-rich nuclei between N=20 and N=28 has been investigated by a novel application of the transient field technique to measure the first-excited state g factors in S-38 and S-40 produced as fast radioactive beams. Details of the new methodology are presented. In both S-38 and S-40 there is a fine balance between the proton and neutron contributions to the magnetic moments. Shell model calculations which describe the level schemes and quadrupole properties of these nuclei also give a satisfactory explanation of the g factors. In S-38 the g factor is extremely sensitive to the occupation of the neutron p3/2 orbit above the N=28 shell gap as occupation of this orbit strongly affects the proton configuration. The g factor of deformed S-40 does not resemble that of a conventional collective nucleus because spin contributions are more important than usual.

  7. Structural lubricity under ambient conditions

    Science.gov (United States)

    Cihan, Ebru; Ipek, Semran; Durgun, Engin; Baykara, Mehmet Z.

    2016-06-01

    Despite its fundamental importance, physical mechanisms that govern friction are poorly understood. While a state of ultra-low friction, termed structural lubricity, is expected for any clean, atomically flat interface consisting of two different materials with incommensurate structures, some associated predictions could only be quantitatively confirmed under ultra-high vacuum (UHV) conditions so far. Here, we report structurally lubric sliding under ambient conditions at mesoscopic (~4,000-130,000 nm2) interfaces formed by gold islands on graphite. Ab initio calculations reveal that the gold-graphite interface is expected to remain largely free from contaminant molecules, leading to structurally lubric sliding. The experiments reported here demonstrate the potential for practical lubrication schemes for micro- and nano-electromechanical systems, which would mainly rely on an atomic-scale structural mismatch between the slider and substrate components, via the utilization of material systems featuring clean, atomically flat interfaces under ambient conditions.

  8. The promoter structure differentiation of a MYB transcription factor RLC1 causes red leaf coloration in Empire Red Leaf Cotton under light.

    Science.gov (United States)

    Gao, Zhenrui; Liu, Chuanliang; Zhang, Yanzhao; Li, Ying; Yi, Keke; Zhao, Xinhua; Cui, Min-Long

    2013-01-01

    The red leaf coloration of Empire Red Leaf Cotton (ERLC) (Gossypium hirsutum L.), resulted from anthocyanin accumulation in light, is a well known dominant agricultural trait. However, the underpin molecular mechanism remains elusive. To explore this, we compared the molecular biological basis of anthocyanin accumulation in both ERLC and the green leaf cotton variety CCRI 24 (Gossypium hirsutum L.). Introduction of R2R3-MYB transcription factor Rosea1, the master regulator anthocyanin biosynthesis in Antirrhinum majus, into CCRI 24 induced anthocyanin accumulation, indicating structural genes for anthocyanin biosynthesis are not defected and the leaf coloration might be caused by variation of regulatory genes expression. Expression analysis found that a transcription factor RLC1 (Red Leaf Cotton 1) which encodes the ortholog of PAP1/Rosea1 was highly expressed in leaves of ERLC but barely expressed in CCRI 24 in light. Ectopic expression of RLC1 from ERLC and CCRI 24 in hairy roots of Antirrhinum majus and CCRI 24 significantly enhanced anthocyanin accumulation. Comparison of RLC1 promoter sequences between ERLC and CCRI 24 revealed two 228-bp tandem repeats presented in ERLC with only one repeat in CCRI 24. Transient assays in cotton leave tissue evidenced that the tandem repeats in ERLC is responsible for light-induced RLC1 expression and therefore anthocyanin accumulation. Taken together, our results in this article strongly support an important step toward understanding the role of R2R3-MYB transcription factors in the regulatory menchanisms of anthocyanin accumulation in red leaf cotton under light.

  9. The promoter structure differentiation of a MYB transcription factor RLC1 causes red leaf coloration in Empire Red Leaf Cotton under light.

    Directory of Open Access Journals (Sweden)

    Zhenrui Gao

    Full Text Available The red leaf coloration of Empire Red Leaf Cotton (ERLC (Gossypium hirsutum L., resulted from anthocyanin accumulation in light, is a well known dominant agricultural trait. However, the underpin molecular mechanism remains elusive. To explore this, we compared the molecular biological basis of anthocyanin accumulation in both ERLC and the green leaf cotton variety CCRI 24 (Gossypium hirsutum L.. Introduction of R2R3-MYB transcription factor Rosea1, the master regulator anthocyanin biosynthesis in Antirrhinum majus, into CCRI 24 induced anthocyanin accumulation, indicating structural genes for anthocyanin biosynthesis are not defected and the leaf coloration might be caused by variation of regulatory genes expression. Expression analysis found that a transcription factor RLC1 (Red Leaf Cotton 1 which encodes the ortholog of PAP1/Rosea1 was highly expressed in leaves of ERLC but barely expressed in CCRI 24 in light. Ectopic expression of RLC1 from ERLC and CCRI 24 in hairy roots of Antirrhinum majus and CCRI 24 significantly enhanced anthocyanin accumulation. Comparison of RLC1 promoter sequences between ERLC and CCRI 24 revealed two 228-bp tandem repeats presented in ERLC with only one repeat in CCRI 24. Transient assays in cotton leave tissue evidenced that the tandem repeats in ERLC is responsible for light-induced RLC1 expression and therefore anthocyanin accumulation. Taken together, our results in this article strongly support an important step toward understanding the role of R2R3-MYB transcription factors in the regulatory menchanisms of anthocyanin accumulation in red leaf cotton under light.

  10. ADJUSTMENT FACTORS AND ADJUSTMENT STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    Tao Benzao

    2003-01-01

    In this paper, adjustment factors J and R put forward by professor Zhou Jiangwen are introduced and the nature of the adjustment factors and their role in evaluating adjustment structure is discussed and proved.

  11. Psychosocial factors underlying physical activity

    Directory of Open Access Journals (Sweden)

    Ji Cheng-Ye

    2007-09-01

    of physical activity on academic achievement and other factors beyond physical health; barriers of not having enough time and having too many assignments perceived to hinder frequent physical activity; and parental approval. More rigorous research on psychosocial determinants with close-ended items developed from these open-ended data and with larger sample sizes of students is necessary. Research with parents and school staff will be needed to understand the perceptions of these stakeholder groups key to creating the students' social environment.

  12. Exploring the Underlying Factor Structure of the Home Literacy Environment (HLE) in the English and Spanish Versions of the Familia Inventory: A Cautionary Tale

    Science.gov (United States)

    Gonzalez, Jorge E.; Taylor, Aaron B.; McCormick, Anita S.; Villareal, Victor; Kim, Minjung; Perez, Erica; Darensbourg, Alicia; Haynes, Rebekah

    2011-01-01

    Few research-based measures of the family literacy environment are commercially available, especially in Spanish. One exception is the Familia Inventory (Taylor, 1995). The present study investigated the 10 subscales of this instrument and the factor structure they imply, using data from a low-socioeconomic (SES), largely Hispanic population.…

  13. Exploring the Underlying Factor Structure of the Home Literacy Environment (HLE) in the English and Spanish Versions of the Familia Inventory: A Cautionary Tale

    Science.gov (United States)

    Gonzalez, Jorge E.; Taylor, Aaron B.; McCormick, Anita S.; Villareal, Victor; Kim, Minjung; Perez, Erica; Darensbourg, Alicia; Haynes, Rebekah

    2011-01-01

    Few research-based measures of the family literacy environment are commercially available, especially in Spanish. One exception is the Familia Inventory (Taylor, 1995). The present study investigated the 10 subscales of this instrument and the factor structure they imply, using data from a low-socioeconomic (SES), largely Hispanic population.…

  14. Structure of polymer chains under confinement

    Indian Academy of Sciences (India)

    Jyotsana Lal

    2008-11-01

    We observe by SANS the structure of neutral polystyrene and charged polystyrene sulphonate chains in semi-dilute solutions confined in a model nanoporous glass, Vycor. The size of the free chains in solution is always larger than the pore diameter, 70. The use of a suitable mixture of hydrogenated and deuterated solvents and polymers enables us to measure directly the form factor of one single chain among the others. Single chain form factor was observed both for bulk and confined chains using the condition of zero average contrast. Our measurements on neutral polymer chains are in agreement with the theoretical predictions established by Daoud and de Gennes for chains confined in a cylindrical pore when the chains are entangled and laterally squeezed but remain ideal at large scale along the cylinder axis because of the screening of the excluded volume interactions (so-called regime of ``semi-dilute cigars"). For confined charged polymers, a peak is observed whose intensity increases with molecular weight and the asymptotic 1/ scattering region is extended compared to the bulk. We infer that the chains are sufficiently extended, under the influence of confinement, to highlight the large scale disordered structure of Vycor even under contrast matched conditions. The asymptotic behaviour of the observed interchain structure factor is ≈ 1/2 and ≈ 1/ for free and confined chains respectively.

  15. Land Use Structure Optimization Under Systematic Framework

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper puts forward the concept of land use structure optimization under spacetime coupling through analyzing the systematic characteristic of land use structure optimization.It mainly expounds the construction of land use structure optimization model at different levels.Lastly,this paper explains the practicableness of land use structure optimization under systematic framework through the example of Qionghai city.

  16. Effect of structural factors on mechanical properties of the magnesium alloy Ma2-1 under quasi-static and high strain rate deformation conditions

    Science.gov (United States)

    Garkushin, G. V.; Razorenov, S. V.; Krasnoveikin, V. A.; Kozulin, A. A.; Skripnyak, V. A.

    2015-02-01

    The elastic limit and tensile strength of deformed magnesium alloys Ma2-1 with different structures and textures were measured with the aim of finding a correlation between the spectrum of defects in the material and the resistance to deformation and fracture under quasi-static and dynamic loading conditions. The studies were performed using specimens in the as-received state after high-temperature annealing and specimens subjected to equal-channel angular pressing at a temperature of 250°C. The anisotropy of strength characteristics of the material after shock compression with respect to the direction of rolling of the original alloy was investigated. It was shown that, in contrast to the quasi-static loading conditions, under the shock wave loading conditions, the elastic limit and tensile strength of the magnesium alloy Ma2-1 after equal-channel angular pressing decrease as compared to the specimens in the as-received state.

  17. Concrete structures under projectile impact

    CERN Document Server

    Fang, Qin

    2017-01-01

    In this book, the authors present their theoretical, experimental and numerical investigations into concrete structures subjected to projectile and aircraft impacts in recent years. Innovative approaches to analyze the rigid, mass abrasive and eroding projectile penetration and perforation are proposed. Damage and failure analyses of nuclear power plant containments impacted by large commercial aircrafts are numerically and experimentally analyzed. Ultra-high performance concrete materials and structures against the projectile impact are developed and their capacities of resisting projectile impact are evaluated. This book is written for the researchers, engineers and graduate students in the fields of protective structures and terminal ballistics.

  18. Revisiting the Factors Underlying Maxillary Midline Diastema

    Directory of Open Access Journals (Sweden)

    Abdullah M. Zakria Jaija

    2016-01-01

    Full Text Available Aim. The aim of this study is to analyze the etiological factors underlying the presence of maxillary midline diastema in a sample of orthodontic patients. Materials and Methods. One hundred patients who fulfill the inclusion criteria were selected from 1355 patients seeking orthodontic treatment. The pretreatment orthodontic records were analyzed. The width of the maxillary midline diastema was measured clinically with a digital caliper at two levels: the mesioincisal angles of the central incisors and five millimeters from the incisal edge. The two measurements were averaged, and patients with diastema of more than 0.5 millimeter in width were enrolled. Results. Diastema is a multifactorial clinical finding with more than one underlying etiological cause. The interrelationship between the familial pattern of midline diastema and the microdontia, macroglossia, labial frenum, and alveolar cleft conforms was clear. The effect of a mesiodens and the upper lateral incisor whether bilaterally missing, unerupted, or peg shaped was minimal. Conclusion. Etiological factors underlying maxillary midline diastema are interconnected. Using a checklist as a guide during handling maxillary midline diastema is important in the different stages of treatment.

  19. Revisiting the Factors Underlying Maxillary Midline Diastema.

    Science.gov (United States)

    Jaija, Abdullah M Zakria; El-Beialy, Amr Ragab; Mostafa, Yehya A

    2016-01-01

    Aim. The aim of this study is to analyze the etiological factors underlying the presence of maxillary midline diastema in a sample of orthodontic patients. Materials and Methods. One hundred patients who fulfill the inclusion criteria were selected from 1355 patients seeking orthodontic treatment. The pretreatment orthodontic records were analyzed. The width of the maxillary midline diastema was measured clinically with a digital caliper at two levels: the mesioincisal angles of the central incisors and five millimeters from the incisal edge. The two measurements were averaged, and patients with diastema of more than 0.5 millimeter in width were enrolled. Results. Diastema is a multifactorial clinical finding with more than one underlying etiological cause. The interrelationship between the familial pattern of midline diastema and the microdontia, macroglossia, labial frenum, and alveolar cleft conforms was clear. The effect of a mesiodens and the upper lateral incisor whether bilaterally missing, unerupted, or peg shaped was minimal. Conclusion. Etiological factors underlying maxillary midline diastema are interconnected. Using a checklist as a guide during handling maxillary midline diastema is important in the different stages of treatment.

  20. Tissue Factor Structure and Function

    Directory of Open Access Journals (Sweden)

    Saulius Butenas

    2012-01-01

    Full Text Available Tissue factor (TF is an integral membrane protein that is essential to life. It is a component of the factor VIIa-TF complex enzyme and plays a primary role in both normal hemostasis and thrombosis. With a vascular injury, TF becomes exposed to blood and binds plasma factor VIIa, and the resulting complex initiates a series of enzymatic reactions leading to clot formation and vascular sealing. Many cells, both healthy, and tumor cells, produce detectable amounts of TF, especially when they are stimulated by various agents. Despite the relative simplicity and small size of TF, there are numerous contradictory reports about the synthesis and presentation of TF on blood cells and circulation in normal blood either on microparticles or as a soluble protein. Another subject of controversy is related to the structure/function of TF. It has been almost commonly accepted that cell-surface-associated TF has low (if any activity, that is, is “encrypted” and requires specific conditions/reagents to become active, that is, “decrypted.” However there is a lack of agreement related to the mechanism and processes leading to alterations in TF function. In this paper TF structure, presentation, and function, and controversies concerning these features are discussed.

  1. Present and future issues central to the understanding of OCD : A review of current research with an emphasis on distinguishing underlying factors linking heterogeneity, structure and treatment resistance

    OpenAIRE

    Dixon, Ina Yasmin

    2012-01-01

    Sammendrag Forfatter: Ina Dixon Tittel: Sentrale utfordringer i forståelsen av OCD: En gjennomgang av eksisterende funn, med sikte på å drøfte underliggende faktorer knyttet til heterogenitet, komorbiditet og behandlingseffekt. Veileder: Nils Inge Landrø Målsetting: Målet med denne oppgaven er å undersøke og presentere eksisterende kunnskap om fenomenologi, struktur og behandling av tvangslidelse (OCD). Hovedformålet er delvis å presentere et multidimensjonalt perspektiv, og samti...

  2. Optimal restructuring strategies under various dynamic factors

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-xuan

    2007-01-01

    Corporate restructuring was identified as a new industrial force that has great impact on economic values and that therefore has become central in daily financial decision making. This article investigates the optimal restructuring strategies under different dynamic factors and their numerous impacts on firm value. The concept of quasi-leverage is introduced and valuation models are built for corporate debt and equity under imperfect market conditions. The model's input variables include the quasi-leverage and other firm-specific parameters, the output variables include multiple corporate security values. The restructuring cost is formulated in the form of exponential function, which allows us to observe the sensitivity of the variation in security values. The unified model and its analytical solution developed in this research allow us to examine the continuous changes of security values by dynamically changing the coupon rates, riskless interest rate, bankruptcy cost, quasi-leverage, personal tax rate, corporate taxes rate, transaction cost, firm risk, etc., so that the solutions provide useful guidance for financing and restructuring decisions.

  3. Factors Underlying Contextual Variations in the Structure of the Self: Differences Related to SES, Gender, Culture, and "Majority/Nonmajority" Status during Early Adolescence

    Science.gov (United States)

    Santo, Jonathan Bruce; Bukowski, William M.; Stella-Lopez, Luz; Carmago, Gina; Mayman, Shari B.; Adams, Ryan E.

    2013-01-01

    Multilevel modeling was used to examine contextual variations in the structure of the "self" in a sample of 918 lower- and upper-middle class early adolescents (M age = 10.37 years, SD = 1.19) from a "majority" cultural context (i.e., Barranquilla in the Caribbean region of Colombia) and a "nonmajority" context (i.e.,…

  4. Factors Underlying Contextual Variations in the Structure of the Self: Differences Related to SES, Gender, Culture, and "Majority/Nonmajority" Status during Early Adolescence

    Science.gov (United States)

    Santo, Jonathan Bruce; Bukowski, William M.; Stella-Lopez, Luz; Carmago, Gina; Mayman, Shari B.; Adams, Ryan E.

    2013-01-01

    Multilevel modeling was used to examine contextual variations in the structure of the "self" in a sample of 918 lower- and upper-middle class early adolescents (M age = 10.37 years, SD = 1.19) from a "majority" cultural context (i.e., Barranquilla in the Caribbean region of Colombia) and a "nonmajority" context (i.e.,…

  5. Water Demand Under Alternative Price Structures

    OpenAIRE

    Sheila Olmstead; W. Michael Hanemann; Robert N. Stavins

    2007-01-01

    We estimate the price elasticity of water demand with household-level data, structurally modeling the piecewise-linear budget constraints imposed by increasing-block pricing. We develop a mathematical expression for the unconditional price elasticity of demand under increasing-block prices and compare conditional and unconditional elasticities analytically and empirically. We test the hypothesis that price elasticity may depend on price structure, beyond technical differences in elasticity co...

  6. Water Demand Under Alternative Price Structures

    OpenAIRE

    Sheila Olmstead; W. Michael Hanemann; Robert N. Stavins

    2007-01-01

    We estimate the price elasticity of water demand with household-level data, structurally modeling the piecewise-linear budget constraints imposed by increasing-block pricing. We develop a mathematical expression for the unconditional price elasticity of demand under increasing-block prices and compare conditional and unconditional elasticities analytically and empirically. We test the hypothesis that price elasticity may depend on price structure, beyond technical differences in elasticity co...

  7. Concurrent Structural Fatigue Damage Prognosis Under Uncertainty

    Science.gov (United States)

    2014-04-30

    level is approximately 57% of the maximum loading without effects left by the overload. The forth diamond symbol is slightly smaller than before (the...Rackwitz, R.a.F., B, Structural Reliablity Under Combined Random Load Sequences. Computers & Structures, 1978. 9(5): p. 484-494. 67. Porter , T.R...mechanically polished (one micron diamond suspension in the last step), which provides a mirror-like surface to facilitate the optical crack length

  8. Predicting the Structural Performance of Composite Structures Under Cyclic Loading

    NARCIS (Netherlands)

    Kassapoglou, C.

    2012-01-01

    The increased use of advanced composite materials on primary aircraft structure has brought back to the forefront the question of how such structures perform under repeated loading. In particular, when damage or other stress risers are present, tests have shown that the load to cause failure after

  9. Structures of Liquid Aluminium under High Pressure

    Institute of Scientific and Technical Information of China (English)

    LI Hui; WANG Guang-Hou; BIAN Xiu-Fang; ZHANG Lin

    2001-01-01

    Molecular dynamics simulation has been carried out for melt A1 under constant temperature and constant pressure. The interaction between atoms is described by tight-binding many-body potentials based on the second moment approximation to the electronic density of states. The pair correlation function and the pair analysis technique are used to reveal the structural features of liquid Al under normal and high pressure. High pressure is favourable to the existence of bcc clusters 1661 and 1441, but has no effect on the fcc cluster 1421. The bond pair 1551 and 1541 with fivefold symmetry exists at high pressure. The microstructure of liquid is more similar to the non-crystalline structure than to the crystalline structure. The simulation results are supported by thex-ray experimental results.

  10. Fatigue in Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    1999-01-01

    types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel with a yield stress of ~ 360-410 MPa or high-strength steel with a yield stress of ~ 810-1010 MPa. The fatigue tests and the fracture mechanics analyses......Fatigue damage accumulation in steel structures under random loading is studied. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part of the investigation, fatigue test series have been carried through on various...... have been carried out using load histories, which are realistic in relation to the types of structures studied, i.e. primarily bridges, offshore structures and chimneys. In general, the test series carried through show a significant difference between constant amplitude and variable amplitude fatigue...

  11. Analysis of flexible structures under lateral impact

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, D. F. [Paul C. Kizzo and Associates Inc., Seismic Structural Group, Oakland, CA 94612 (United States); Razavi, H. [AREVA Inc., Civil Seismic Group, San Jose, CA 95119 (United States)

    2012-07-01

    Three methods for analysis of flexible structures under lateral impact are presented. The first proposed method (Method A) consists of: (1) modifying an available deceleration on a rigid target with conservation principles to account for structural flexibility; and (2) transient nonlinear analysis of the structure with the corrected forcing function. The second proposed method (Method B) is similar to Method A in obtaining the forcing function but it solves the equations of motion of an idealized two-degree-of-freedom system instead of directly using conservation principles. The last method simply provides the maximum force in the structure using the conservation of energy and linear momentum. A coupled simulation is also performed in LS-DYNA and compared against the proposed methods. A case study is presented to illustrate the applicability of all three methods and the LS-DYNA simulation. (authors)

  12. Structural Reliability Sensitivities under Nonstationary Random Vibrations

    Directory of Open Access Journals (Sweden)

    Rita Greco

    2013-01-01

    Full Text Available Response sensitivity evaluation is an important element in reliability evaluation and design optimization of structural systems. It has been widely studied under static and dynamic forcing conditions with deterministic input data. In this paper, structural response and reliability sensitivities are determined by means of the time domain covariance analysis in both classically and nonclassically damped linear structural systems. A time integration scheme is proposed for covariance sensitivity. A modulated, filtered, white noise input process is adopted to model the stochastic nonstationary loads. The method allows for the evaluation of sensitivity statistics of different quantities of dynamic response with respect to structural parameters. Finally, numerical examples are presented regarding a multistorey shear frame building.

  13. Underlying Factors for Practicality of the Production Control Systems

    DEFF Research Database (Denmark)

    Arica, Emrah; Strandhagen, Jan Ola; Hvolby, Hans-Henrik

    2012-01-01

    This paper gives indications to important factors that must be considered for effectiveness of the production control systems under uncertainty. Five key factors have been identified by the literature study. Production schedule generation and execution approach under uncertainty, information...

  14. Comparing Factor Structures of Adolescent Psychopathology

    Science.gov (United States)

    Verona, Edelyn; Javdani, Shabnam; Sprague, Jenessa

    2011-01-01

    Research on the structure of adolescent psychopathology can provide information on broad factors that underlie different forms of maladjustment in youths. Multiple studies from the literature on adult populations suggest that 2 factors, Internalizing and Externalizing, meaningfully comprise the factor structure of adult psychopathology (e.g.,…

  15. Comparing Factor Structures of Adolescent Psychopathology

    Science.gov (United States)

    Verona, Edelyn; Javdani, Shabnam; Sprague, Jenessa

    2011-01-01

    Research on the structure of adolescent psychopathology can provide information on broad factors that underlie different forms of maladjustment in youths. Multiple studies from the literature on adult populations suggest that 2 factors, Internalizing and Externalizing, meaningfully comprise the factor structure of adult psychopathology (e.g.,…

  16. Thermomechanics of composite structures under high temperatures

    CERN Document Server

    Dimitrienko, Yu I

    2016-01-01

    This pioneering book presents new models for the thermomechanical behavior of composite materials and structures taking into account internal physico-chemical transformations such as thermodecomposition, sublimation and melting at high temperatures (up to 3000 K). It is of great importance for the design of new thermostable materials and for the investigation of reliability and fire safety of composite structures. It also supports the investigation of interaction of composites with laser irradiation and the design of heat-shield systems. Structural methods are presented for calculating the effective mechanical and thermal properties of matrices, fibres and unidirectional, reinforced by dispersed particles and textile composites, in terms of properties of their constituent phases. Useful calculation methods are developed for characteristics such as the rate of thermomechanical erosion of composites under high-speed flow and the heat deformation of composites with account of chemical shrinkage. The author expan...

  17. Genomic inflation factors under polygenic inheritance

    NARCIS (Netherlands)

    Yang, Jian; Weedon, Michael N.; Purcell, Shaun; Lettre, Guillaume; Estrada, Karol; Willer, Cristen J.; Smith, Albert V.; Ingelsson, Erik; O'Connell, Jeffrey R.; Mangino, Massimo; Maegi, Reedik; Madden, Pamela A.; Heath, Andrew C.; Nyholt, Dale R.; Martin, Nicholas G.; Montgomery, Grant W.; Frayling, Timothy M.; Hirschhorn, Joel N.; McCarthy, Mark I.; Goddard, Michael E.; Visscher, Peter M.

    2011-01-01

    Population structure, including population stratification and cryptic relatedness, can cause spurious associations in genome-wide association studies (GWAS). Usually, the scaled median or mean test statistic for association calculated from multiple single-nucleotide-polymorphisms across the genome i

  18. Strength of concrete structures under dynamic loading

    Energy Technology Data Exchange (ETDEWEB)

    Kumpyak, O. G., E-mail: ogkumpyak@yandex.ru; Galyautdinov, Z. R., E-mail: gazr@yandex.ru; Kokorin, D. N., E-mail: kokorindenn@yandex.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation)

    2016-01-15

    The use of elastic supports is one the efficient methods of decreasing the dynamic loading. The paper describes the influence of elastic supports on the stress-strain state of steel concrete structures exposed to one-time dynamic loading resulting in failure. Oblique bending beams on elastic supports and their elastic, elastoplastic, and elastoplastic consolidation behavior are considered in this paper. For numerical calculations the developed computer program is used based on the finite element method. Research findings prove high efficiency of elastic supports under dynamic loading conditions. The most effective behavior of elastic supports is demonstrated at the elastoplastic stage. A good agreement is observed between the theoretical and experimental results.

  19. Factor structure of emotional intelligence in schizophrenia.

    Science.gov (United States)

    Lin, Yu-Chung; Wynn, Jonathan K; Hellemann, Gerhard; Green, Michael F

    2012-08-01

    Social cognition, which includes emotional intelligence, is impaired in schizophrenia. The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) is a widely-used assessment of emotional intelligence, with a four-factor structure in healthy individual. However, a recent factor analysis in schizophrenia patients revealed a two-factor structure of the MSCEIT. The current study aimed to replicate this finding in a larger, more diverse, schizophrenia sample (n=194). Our findings revealed an identical two-factor structure as in the previously-reported study, indicating that emotional intelligence is organized in a different manner in schizophrenia than it is in healthy controls.

  20. Eysenck Personality Inventory Item Factor Structure.

    Science.gov (United States)

    Comrey, Andrew L.; And Others

    1988-01-01

    Three methods were used to test the factor structure of the Eysenck Personality Inventory administered to 583 Australians. The preferred method was to extract factors by the minimum residual method, use the Tandem Criteria Method, and then rotate that number of factors by the Tandem Criteria I method. (SLD)

  1. Structural transition of FeSe under high pressure

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Chen Jun-Fang; He Qin-Yu; Wang Teng; Pan Zhong-Liang

    2011-01-01

    The density functional calculations of the energy band structure and density of state for the tetragonal PbO-type phase α-FeSe and hexagonal NiAs-type phase β-FeSe are reported in this paper. The structural phase transition from tetragonal to hexagonal FeSe under high pressure is investigated, it is found that the calculated transition pressure for the α→β phase transformation is 8.5 GPa. Some fluctuations in the transition pressure maybe occurred by different external factors such as temperature and stress condition. There is about 17% volume collapse accompanying the α→β phase transformation.

  2. Structure service life assessment under combined loading using probability approach

    Directory of Open Access Journals (Sweden)

    Miloslav Kepka

    2016-10-01

    Full Text Available This article presents a basic research approach for probabilistic assessment of vehicle structure fatigue endurance under multiaxial loading. One representative welded structural detail of the bottom joint plate of an articulated bus was selected for the case study. The character of the loading on the joint during a service test is analyzed and discussed. The methodology for estimation of the damage level in the joint builds on deterministic procedures for railway vehicle assessment based on shear, longitudinal and transverse stress components. This approach based on the equivalent stress and particular load capacity factors was expanded to include the probabilistic perspective

  3. Sensitivity to Factors Underlying the Hiatus

    Science.gov (United States)

    Marvel, Kate; Schmidt, Gavin A.; Tsigaridis, Kostas; Cook, Benjamin I.

    2015-01-01

    Recent trends in global mean surface air temperature fall outside the 90 range predicted by models using the CMIP5 forcings and scenarios; this recent period of muted warming is dubbed the hiatus. The hiatus has attracted broad attention in both the popular press and the scientific literature, primarily because of its perceived implications for understanding long-term trends. Many hypotheses have been offered to explain the warming slowdown during the hiatus, and comprehensive studies of this period across multiple variables and spatial scales will likely improve our understanding of the physical mechanisms driving global temperature change and variability.We argue, however, that decadal temperature trends by themselves are unlikely to constrain future trajectories of global mean temperature and that the hiatus does not significantly revise our understanding of overall climate sensitivity. Instead, we demonstrate that, because of the poorly constrained nature of the hiatus, model-observation disagreements over this period may be resolvable via uncertainties in the observations, modeled internal variability, forcing estimates, or (more likely) some combination of all three factors. We define the hiatus interval as 1998-2012, endpoints judiciously chosen to minimize observed warming by including the large 1998 El Nio event and excluding 2014, an exceptionally warm year. Such choices are fundamentally subjective and cannot be considered random, so any probabilistic statements regarding the likelihood of this occurring need to be made carefully. Using this definition, the observed global temperature trend estimates from four datasets fall outside the 5-95 interval predicted by the CMIP5 models. Here we explore some of the plausible explanations for this discrepancy, and show that no unique explanation is likely to fully account for the hiatus.

  4. The Factor Structure in Equity Options

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Jacobs, Kris

    Principal component analysis of equity options on Dow-Jones firms reveals a strong factor structure. The first principal component explains 77% of the variation in the equity volatility level, 77% of the variation in the equity option skew, and 60% of the implied volatility term structure across...... equities. Furthermore, the first principal component has a 92% correlation with S&P500 index option volatility, a 64% correlation with the index option skew, and a 80% correlation with the index option term structure. We develop an equity option valuation model that captures this factor structure...

  5. Study about the Asymmetry Competing Channel Structure under Bargaining Power

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lan; AI Xing-zheng

    2005-01-01

    On the problem of competing channel structure, we present asymmetry competing channel structure models under bargaining power, analyze the evolving process of channel structure under different bargaining power and product nature, find different bargaining power and product nature important role for channel structure, and also present equilibrium result. Furthermore, the academic proof for channel structure choice is presented.

  6. Exploring the factor structure of neurocognitive measures in older individuals.

    Science.gov (United States)

    Santos, Nadine Correia; Costa, Patrício Soares; Amorim, Liliana; Moreira, Pedro Silva; Cunha, Pedro; Cotter, Jorge; Sousa, Nuno

    2015-01-01

    Here we focus on factor analysis from a best practices point of view, by investigating the factor structure of neuropsychological tests and using the results obtained to illustrate on choosing a reasonable solution. The sample (n=1051 individuals) was randomly divided into two groups: one for exploratory factor analysis (EFA) and principal component analysis (PCA), to investigate the number of factors underlying the neurocognitive variables; the second to test the "best fit" model via confirmatory factor analysis (CFA). For the exploratory step, three extraction (maximum likelihood, principal axis factoring and principal components) and two rotation (orthogonal and oblique) methods were used. The analysis methodology allowed exploring how different cognitive/psychological tests correlated/discriminated between dimensions, indicating that to capture latent structures in similar sample sizes and measures, with approximately normal data distribution, reflective models with oblimin rotation might prove the most adequate.

  7. Exploring the factor structure of neurocognitive measures in older individuals.

    Directory of Open Access Journals (Sweden)

    Nadine Correia Santos

    Full Text Available Here we focus on factor analysis from a best practices point of view, by investigating the factor structure of neuropsychological tests and using the results obtained to illustrate on choosing a reasonable solution. The sample (n=1051 individuals was randomly divided into two groups: one for exploratory factor analysis (EFA and principal component analysis (PCA, to investigate the number of factors underlying the neurocognitive variables; the second to test the "best fit" model via confirmatory factor analysis (CFA. For the exploratory step, three extraction (maximum likelihood, principal axis factoring and principal components and two rotation (orthogonal and oblique methods were used. The analysis methodology allowed exploring how different cognitive/psychological tests correlated/discriminated between dimensions, indicating that to capture latent structures in similar sample sizes and measures, with approximately normal data distribution, reflective models with oblimin rotation might prove the most adequate.

  8. socio-demographic factors in under five children with acute ...

    African Journals Online (AJOL)

    2013-09-01

    Sep 1, 2013 ... Their socio-demographic factors such as age, sex, breastfeeding status, parents ... acute diarrhoea among under five children in Enugu, Nigeria. ... Malnutrition predisposes .... Determinants of the utilization of children's Health.

  9. nutritional status of children under five years and associated factors ...

    African Journals Online (AJOL)

    ACSS

    Identification of core factors influencing nutrition of this population supports plans to alleviate child ... This study sought to determine the nutritional status of children under five years and associated ... The primary determinants of malnutrition as.

  10. Factors Underlying the Development of Orofacial Pathology in Athletes

    Directory of Open Access Journals (Sweden)

    Dmitry I. Karpovich

    2014-06-01

    Full Text Available This work addresses the factors underlying the development of orofacial pathology in athletes. The author has assessed the significance and practical value of these factors and has made an attempt to establish a link between it and somatic pathology in athletes.

  11. Generalizing Linguistic Structures under High Attention Demands

    Science.gov (United States)

    Toro, Juan M.; Sinnett, Scott; Soto-Faraco, Salvador

    2011-01-01

    We explored whether the generalization of rules based on simple structures depends on attention. Participants were exposed to a stream of artificial words that followed a simple syllabic structure (ABA or AAB), overlaid on a sequence of familiar noises. After passively listening, participants successfully recognized the individual words present in…

  12. On R factors for dynamic structure crystallography

    DEFF Research Database (Denmark)

    Coppens, Philip; Kaminski, Radoslaw; Schmøkel, Mette Stokkebro

    2010-01-01

    In studies of dynamic changes in crystals in which induced metastable species may have lifetimes of microseconds or less, refinements are most sensitive if based on the changes induced in the measured intensities. Agreement factors appropriate for such refinements, based on the ratios of the inte...... of the intensities before and after the external perturbation is applied, are discussed and compared with R factors commonly applied in static structure crystallography....

  13. Predicting structure in nonsymmetric sparse matrix factorizations

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, J.R. (Xerox Palo Alto Research Center, CA (United States)); Ng, E.G. (Oak Ridge National Lab., TN (United States))

    1992-10-01

    Many computations on sparse matrices have a phase that predicts the nonzero structure of the output, followed by a phase that actually performs the numerical computation. We study structure prediction for computations that involve nonsymmetric row and column permutations and nonsymmetric or non-square matrices. Our tools are bipartite graphs, matchings, and alternating paths. Our main new result concerns LU factorization with partial pivoting. We show that if a square matrix A has the strong Hall property (i.e., is fully indecomposable) then an upper bound due to George and Ng on the nonzero structure of L + U is as tight as possible. To show this, we prove a crucial result about alternating paths in strong Hall graphs. The alternating-paths theorem seems to be of independent interest: it can also be used to prove related results about structure prediction for QR factorization that are due to Coleman, Edenbrandt, Gilbert, Hare, Johnson, Olesky, Pothen, and van den Driessche.

  14. Factor structure of Raven's Coloured Progressive Matrices

    OpenAIRE

    Muniz, Monalisa; Gomes, Cristiano Mauro Assis; Pasian, Sonia Regina

    2016-01-01

    Abstract This study's objective was to verify the factor structure of Raven's Coloured Progressive Matrices (CPM). The database used included the responses of 1,279 children, 50.2% of which were males with an average age of 8.48 years old and a standard deviation of 1.49 yrs. Confirmatory factor analyses were run to test seven models based on CPM theory and on a Brazilian study addressing the test's structure. The results did not confirm the CPM theoretical proposition concerning the scales b...

  15. Structural studies on leukaemia inhibitory factor

    Energy Technology Data Exchange (ETDEWEB)

    Norton, R.S.; Maurer, T.; Smith, D.K. [Biomolecular Research Institute, Parville (Australia); Nicola, N.A. [Institute of Medical Research, Melbourne (Australia)

    1994-12-01

    Leukaemia Inhibitory Factor (LIF) is a pleiotropic cytokine that acts on a wide range of target cells, including mega-karyocytes, osteoblasts, hepatocytes, adipocytes, neurons, embryonic stem cells, and primordial germ cells. Many of its activities are shared with other cytokines, particularly interleukin-6, oncostatin-M, ciliary neurotrophic factor, and granulocyte colony-stimulating factor (G-CSF). Although secreted in vivo as a glycoprotein, nonglycosylated recombinant protein expressed in E. coli is fully active and has been used in our nuclear magnetic resonance (NMR) studies of the three-dimensional structure and structure-function relationships of LIF. With 180 amino acids and a molecular mass of about 20 kDa, OF is too large for direct structure determination by two-dimensional and three-dimensional {sup 1}HNMR. It is necessary to label the protein with the stable isotopes {sup 15}N and {sup 13}C and employ heteronuclear three-dimensional NMR in order to resolve and interpret the spectral information required for three-dimensional structure determination. This work has been undertaken with both human LIF and a mouse-human chimaera that binds to the human LIF receptor with the same affinity as the human protein and yet expresses in E. coli at much higher levels. Sequence-specific resonance assignments and secondary structure elements for these proteins will be presented and progress towards determination of their three-dimensional structures described.

  16. Curved Nanotube Structures under Mechanical Loading

    Directory of Open Access Journals (Sweden)

    Hamidreza Yazdani Sarvestani

    2015-01-01

    Full Text Available Configuration of carbon nanotube (CNT has been the subject of research to perform theoretical development for analyzing nanocomposites. A new theoretical solution is developed to study curved nanotube structures subjected to mechanical loadings. A curved nanotube structure is considered. A nonlocal displacement-based solution is proposed by using a displacement approach of Toroidal Elasticity based on Eringen’s theory of nonlocal continuum mechanics. The governing equations of curved nanotube structures are developed in toroidal coordinate system. The method of successive approximation is used to discretize the displacement-based governing equations and find the general solution subjected to bending moment. The numerical results show that all displacement components increase with increasing the nonlocal parameter. The present theoretical study highlights the significance of the geometry and nonlocal parameter effects on mechanical behavior of nanotube structures.

  17. Rheology and Structure of Quenched Binary Mixtures Under Oscillatory Shear

    Institute of Scientific and Technical Information of China (English)

    XU Ai-Guo

    2003-01-01

    We applied the D2Q9 BGK lattice Boltzmann method to study the rheology and structure of the phaseseparating binary fluids under oscillatory shear in the diffusive regime. The method is suitable for simulating systemswhose dynamicsis described by the Navier-Stokes equation and convection-diffusion equation. The shear oscillationinduces different rheological patterns from those under steady shear. With the increasing of the frequency of the shearthe system shows more isotropic behavior, while with the decreasing of the frequency we find more configurations similarto those under steady shear. By decreasing the frequency of the shear, the period of the applied flow becomes thesame order of the relaxation time of the shear velocity profile, which is inversely proportional to the viscosity, and moreanisotropic effects become observable. The structure factor and the velocity profile contribute to the understanding ofthe configurations and the kinetic process. Oscillatory shear induces nonlinear pattern of the horizontal velocity profile.Therefore, configurations are found where lamellar order close to the wall coexists with isotropic domains in the middleof the system. For very slow frequencies, the morphology of the domains is characterized by lamellar order everywherethat resembles what happens in the case of steady shear.

  18. The structure of musical preferences: a five-factor model.

    Science.gov (United States)

    Rentfrow, Peter J; Goldberg, Lewis R; Levitin, Daniel J

    2011-06-01

    Music is a cross-cultural universal, a ubiquitous activity found in every known human culture. Individuals demonstrate manifestly different preferences in music, and yet relatively little is known about the underlying structure of those preferences. Here, we introduce a model of musical preferences based on listeners' affective reactions to excerpts of music from a wide variety of musical genres. The findings from 3 independent studies converged to suggest that there exists a latent 5-factor structure underlying music preferences that is genre free and reflects primarily emotional/affective responses to music. We have interpreted and labeled these factors as (a) a Mellow factor comprising smooth and relaxing styles; (b) an Unpretentious factor comprising a variety of different styles of sincere and rootsy music such as is often found in country and singer-songwriter genres; (c) a Sophisticated factor that includes classical, operatic, world, and jazz; (d) an Intense factor defined by loud, forceful, and energetic music; and (e) a Contemporary factor defined largely by rhythmic and percussive music, such as is found in rap, funk, and acid jazz. The findings from a fourth study suggest that preferences for the MUSIC factors are affected by both the social and the auditory characteristics of the music.

  19. Factor Structure and Reliability of the Revised Conflict Tactics Scales' (CTS2) 10-Factor Model in a Community-Based Female Sample

    Science.gov (United States)

    Yun, Sung Hyun

    2011-01-01

    The present study investigated the factor structure and reliability of the revised Conflict Tactics Scales' (CTS2) 10-factor model in a community-based female sample (N = 261). The underlying factor structure of the 10-factor model was tested by the confirmatory multiple group factor analysis, which demonstrated complex factor cross-loadings…

  20. Detonation Structure Under Chain Branching Kinetics

    Science.gov (United States)

    Liang, Z.; Bauwens, L.

    2006-07-01

    Hydrogen-oxygen chemistry is characterized by a chain branching mechanism that yields three explosion limits. While a detailed kinetic scheme appropriate for hydrogen-oxygen should produce correct results, in many circumstances, a simpler yet reasonably realistic model will be warranted. In particular, it is easier to develop a clear understanding of the reaction zone structure using a simpler model, that includes only the key mechanisms. To that effect, we consider a four-step chain branching scheme that exhibits an explosion behavior with three limits, which behaves at least qualitatively like hydrogen chemistry. We focus in particular on the structure of the initiation and chain branching zones, using a combination between numerical simulation and analysis. Numerical simulations using this chemical model show distinctive keystone figures in the flow field, close to observations in hydrogen-oxygen detonation experiments. The structure of the chain branching zone is resolved using a perturbation analysis, which clarifies the differences between explosion and no-explosion regions and allows for an evaluation of the induction length in the steady wave. The analysis assumes both high activation energy and a slow initiation. Three cases are identified, respectively, with pressure and temperature located within the explosion region, close to the explosion limit and within the no-explosion region. The induction length is shorter and the reaction rate is faster by several orders of magnitude in the explosion region.

  1. Robustness Assessment of Building Structures under Explosion

    Directory of Open Access Journals (Sweden)

    Mark Waggoner

    2012-12-01

    Full Text Available Over the past decade, much research has focused on the behaviour of structures following the failure of a key structural component. Particular attention has been given to sudden column loss, though questions remain as to whether this event-independent scenario is relevant to actual extreme events such as explosion. Few studies have been conducted to assess the performance of floor slabs above a failed column, and the computational tools used have not been validated against experimental results. The research program presented in this paper investigates the adequacy of sudden column loss as an idealisation of local damage caused by realistic explosion events, and extends prior work by combining the development of accurate computational models with large-scale testing of a typical floor system in a prototypical steel-framed structure. The floor system consists of corrugated decking topped by a lightly reinforced concrete slab that is connected to the floor beams through shear studs. The design is consistent with typical building practices in the US. The first test has been completed, and subsequent tests are currently being planned. This paper addresses the importance of robustness design for localized damage and includes a detailed description regarding how the research program advances the current state of knowledge for assessing robustness of compositely constructed steel-framed buildings.

  2. Improving the Factor Structure of Psychological Scales

    Science.gov (United States)

    Zhang, Xijuan; Savalei, Victoria

    2015-01-01

    Many psychological scales written in the Likert format include reverse worded (RW) items in order to control acquiescence bias. However, studies have shown that RW items often contaminate the factor structure of the scale by creating one or more method factors. The present study examines an alternative scale format, called the Expanded format, which replaces each response option in the Likert scale with a full sentence. We hypothesized that this format would result in a cleaner factor structure as compared with the Likert format. We tested this hypothesis on three popular psychological scales: the Rosenberg Self-Esteem scale, the Conscientiousness subscale of the Big Five Inventory, and the Beck Depression Inventory II. Scales in both formats showed comparable reliabilities. However, scales in the Expanded format had better (i.e., lower and more theoretically defensible) dimensionalities than scales in the Likert format, as assessed by both exploratory factor analyses and confirmatory factor analyses. We encourage further study and wider use of the Expanded format, particularly when a scale’s dimensionality is of theoretical interest. PMID:27182074

  3. Materials and structures under shock and impact

    CERN Document Server

    Bailly, Patrice

    2013-01-01

    In risk studies, engineers often have to consider the consequences of an accident leading to a shock on a construction. This can concern the impact of a ground vehicle or aircraft, or the effects of an explosion on an industrial site.This book presents a didactic approach starting with the theoretical elements of the mechanics of materials and structures, in order to develop their applications in the cases of shocks and impacts. The latter are studied on a local scale at first. They lead to stresses and strains in the form of waves propagating through the material, this movement then extending

  4. Donation to disaster relief campaigns: underlying social cognitive factors exposed

    NARCIS (Netherlands)

    Oosterhof, Liesbeth; Heuvelman, Ard; Peters, Oscar

    2009-01-01

    number of very serious natural disasters have put an enormous pressure on relief organizations in the last few years. The present study exposes underlying social cognitive factors for donation to relief campaigns. A causal model was constructed, based on social cognitive theory, research on attitude

  5. Factors Underlying Second Language Reading Motivation of Adult EAP Students

    Science.gov (United States)

    Komiyama, Reiko

    2013-01-01

    Characteristics of English for Academic Purposes students' second language (L2) motivation were examined by identifying underlying motivational factors. Using the motivation constructs created by first language reading researchers, a survey was developed and administered to 2,018 students from 53 English language programs in the U.S. Survey…

  6. Factors Underlying Second Language Reading Motivation of Adult EAP Students

    Science.gov (United States)

    Komiyama, Reiko

    2013-01-01

    Characteristics of English for Academic Purposes students' second language (L2) motivation were examined by identifying underlying motivational factors. Using the motivation constructs created by first language reading researchers, a survey was developed and administered to 2,018 students from 53 English language programs in the U.S. Survey…

  7. Factors underlying male and female use of violent video games

    NARCIS (Netherlands)

    Hartmann, T.; Möller, I.; Krause, C.

    2015-01-01

    Research has consistently shown that males play violent video games more frequently than females, but factors underlying this gender gap have not been examined to date. This approach examines the assumption that males play violent video games more because they anticipate more enjoyment and less

  8. Factors underlying male and female use of violent video games

    NARCIS (Netherlands)

    Hartmann, T.; Möller, I.; Krause, C.

    2015-01-01

    Research has consistently shown that males play violent video games more frequently than females, but factors underlying this gender gap have not been examined to date. This approach examines the assumption that males play violent video games more because they anticipate more enjoyment and less guil

  9. Factors Underlying Second Language Reading Motivation of Adult EAP Students

    Science.gov (United States)

    Komiyama, Reiko

    2013-01-01

    Characteristics of English for Academic Purposes students' second language (L2) motivation were examined by identifying underlying motivational factors. Using the motivation constructs created by first language reading researchers, a survey was developed and administered to 2,018 students from 53 English language programs in the U.S. Survey…

  10. Donation to disaster relief campaigns: underlying social cognitive factors exposed

    NARCIS (Netherlands)

    Oosterhof, Liesbeth; Heuvelman, A.; Peters, O.

    2009-01-01

    number of very serious natural disasters have put an enormous pressure on relief organizations in the last few years. The present study exposes underlying social cognitive factors for donation to relief campaigns. A causal model was constructed, based on social cognitive theory, research on attitude

  11. Structural Factors Affecting Health Examination Behavioral Intention.

    Science.gov (United States)

    Huang, Hui-Ting; Kuo, Yu-Ming; Wang, Shiang-Ru; Wang, Chia-Fen; Tsai, Chung-Hung

    2016-04-01

    Disease screening instruments used for secondary prevention can facilitate early determination and treatment of pathogenic factors, effectively reducing disease incidence, mortality rates, and health complications. Therefore, people should be encouraged to receive health examinations for discovering potential pathogenic factors before symptoms occur. Here, we used the health belief model as a foundation and integrated social psychological factors and investigated the factors influencing health examination behavioral intention among the public in Taiwan. In total, 388 effective questionnaires were analyzed through structural model analysis. Consequently, this study yielded four crucial findings: (1) The established extended health belief model could effectively predict health examination behavioral intention; (2) Self-efficacy was the factor that most strongly influenced health examination behavioral intention, followed by health knowledge; (3) Self-efficacy substantially influenced perceived benefits and perceived barriers; (4) Health knowledge and social support indirectly influenced health examination behavioral intention. The preceding results can effectively increase the acceptance and use of health examination services among the public, thereby facilitating early diagnosis and treatment and ultimately reducing disease and mortality rates.

  12. Aircraft passenger comfort experience: underlying factors and differentiation from discomfort.

    Science.gov (United States)

    Ahmadpour, Naseem; Robert, Jean-Marc; Lindgaard, Gitte

    2016-01-01

    Previous studies defined passengers' comfort based on their concerns during the flight and a set of eight experiential factors such as 'peace of mind', 'physical wellbeing', 'pleasure', etc. One Objective of this paper was to determine whether the factors underlying the passengers' experience of comfort differ from those of discomfort. Another objective was to cross-validate those factors. In the first study, respondents provided written reports of flight comfort and discomfort experiences separately and gave ratings on the impact of the eight factors on each experience. Follow up interviews were also conducted. Significant difference was found between comfort and discomfort ratings for two factors of 'pleasure', denoted by one's concern for stimulation, ambience and exceeded expectations, and 'physical wellbeing' characterized in terms of bodily support and energy. However, there were no significant differences between the comfort and discomfort ratings on the other six factors. The evidence does not support the proposition that passenger comfort and discomfort are underline by different sets of factors. It is therefore suggested that the evaluation of overall passenger comfort experience, as a whole, employ one spectrum ranging from extreme comfort to discomfort. In study two, a pool of comfort descriptors was collected. Those that were less relevant to passenger comfort were eliminated in a number of steps. Factor analysis was used to classify the remaining descriptors, using respondents' ratings on their potential impact on passenger comfort. Seven factors corresponded to the pre-determined passenger comfort factors from previous research, validating those with an exception of 'proxemics' (concerning one's privacy and control over their situation) but it was argued that this is due to the nature of the factor itself, which is context dependent and generally perceived unconsciously.

  13. Empirical Analysis of Farm Credit Risk under the Structure Model

    Science.gov (United States)

    Yan, Yan

    2009-01-01

    The study measures farm credit risk by using farm records collected by Farm Business Farm Management (FBFM) during the period 1995-2004. The study addresses the following questions: (1) whether farm's financial position is fully described by the structure model, (2) what are the determinants of farm capital structure under the structure model, (3)…

  14. Empirical Analysis of Farm Credit Risk under the Structure Model

    Science.gov (United States)

    Yan, Yan

    2009-01-01

    The study measures farm credit risk by using farm records collected by Farm Business Farm Management (FBFM) during the period 1995-2004. The study addresses the following questions: (1) whether farm's financial position is fully described by the structure model, (2) what are the determinants of farm capital structure under the structure model, (3)…

  15. Study about the Competing Channel Structure under Bargaining Power

    Institute of Scientific and Technical Information of China (English)

    AI Xing-zheng; ZHANG Chi

    2005-01-01

    From the bargaining process, competing channel structure models are presented. The evolving process of channel structure under different bargaining power is analyzed. The important role of different bargaining power is discussed and the equilibrium result is found. Also the theoretical evidences for competing channel structure choice are given.

  16. Latent factor structure of a behavioral economic marijuana demand curve.

    Science.gov (United States)

    Aston, Elizabeth R; Farris, Samantha G; MacKillop, James; Metrik, Jane

    2017-08-01

    Drug demand, or relative value, can be assessed via analysis of behavioral economic purchase task performance. Five demand indices are typically obtained from drug purchase tasks. The goal of this research was to determine whether metrics of marijuana reinforcement from a marijuana purchase task (MPT) exhibit a latent factor structure that efficiently characterizes marijuana demand. Participants were regular marijuana users (n = 99; 37.4% female, 71.5% marijuana use days [5 days/week], 15.2% cannabis dependent) who completed study assessments, including the MPT, during a baseline session. Principal component analysis was used to examine the latent structure underlying MPT indices. Concurrent validity was assessed via examination of relationships between latent factors and marijuana use, past quit attempts, and marijuana expectancies. A two-factor solution was confirmed as the best fitting structure, accounting for 88.5% of the overall variance. Factor 1 (65.8% variance) reflected "Persistence," indicating sensitivity to escalating marijuana price, which comprised four MPT indices (elasticity, O max, P max, and breakpoint). Factor 2 (22.7% variance) reflected "Amplitude," indicating the amount consumed at unrestricted price (intensity). Persistence factor scores were associated with fewer past marijuana quit attempts and lower expectancies of negative use outcomes. Amplitude factor scores were associated with more frequent use, dependence symptoms, craving severity, and positive marijuana outcome expectancies. Consistent with research on alcohol and cigarette purchase tasks, the MPT can be characterized with a latent two-factor structure. Thus, demand for marijuana appears to encompass distinct dimensions of price sensitivity and volumetric consumption, with differential relations to other aspects of marijuana motivation.

  17. Impacts on Power Factor of AC Voltage Controllers Under Non-Sinusoidal Conditions

    Directory of Open Access Journals (Sweden)

    Mukhtiar Ahmed Mahar

    2012-04-01

    Full Text Available AC-AC conversion is obtained with the help of Cyclo-converters, DC Link converters and AC Voltage Controllers. AC voltage controllers are also referred to as voltage regulators. Main issue concerned to these converters is that they generate harmonics due to periodic variable structure system. The generated harmonics create disturbances and degrade the performance of converter. The power factor of supply side is affected due to these harmonics. This paper focuses on source side power factor of ac voltage controllers under nonsinusoidal conditions. In order to observe the power factor, measurement tool of power factor and simulation model of ac voltage controller is also developed in MATLAB software.

  18. The factor structure of six salutogenic constructs

    Directory of Open Access Journals (Sweden)

    Marita Breed

    2006-01-01

    Full Text Available The aim of this research was to investigate the factor structure of six salutogenic constructs, namely sense of coherence, hardiness, learned resourcefulness, potency, internal locus of control and self-efficacy. Measurement with a sample of 935 part-time students did not fit the conceptualisation of salutogenesis. A different factor structure for Whites versus Others occurred. For Whites, all six constructs more or less contributed towards the general salutogenic factor and for Others all but learned resourcefulness contributed. For Whites, salutogenesis consisted of two clear dimensions (a global positive orientation; specific behavioural skills and for Others one dimension (an optimistic life view. Confirmatory factor analysis performed on the data for both groups, indicated a weak fit. It was recommended that salutogenesis be further explored within an overall personality theory. Opsomming Die doel van hierdie navorsing was om die faktorstruktuur van ses salutogeniese konstrukte te ondersoek, naamlik sin vir koherensie, gehardheid, aangeleerde vindingrykheid, potensie, interne lokus van beheer en selfgenoegsaamheid. Meting met ‘n steekproef van 935 deeltydse studente het nie ‘n passing getoon met die konseptualisering van salutogenese nie. ‘n Eiesoortige faktorstruktuur vir Wit studente versus Ander studente het voorgekom. Vir Wittes, het al ses die konstrukte meer of minder bygedra tot die algemene salutugeniese faktor en vir Andere het almal behalwe aangeleerde vindingrykheid bygedra. Vir Wittes bestaan salutogenese uit twee duidelike dimensies (‘n globale positiewe lewensorientasie; spesifieke gedrags vaardighede en vir Andere uit een dimensie (‘n optimistiese lewensbeskouing. Bevestigende faktor ontleding uitgevoer op die data van beide groepe, het ‘n swak passing getoon. Daar is aanbeveel dat salutogenese verder ondersoek word binne ‘n oorkoepelende persoonlikheidsteorie.

  19. Recovery of weak factor loadings when adding the mean structure in confirmatory factor analysis: A simulation study

    Directory of Open Access Journals (Sweden)

    Carmen eXiménez

    2016-01-01

    Full Text Available This article extends previous research on the recovery of weak factor loadings in confirmatory factor analysis by exploring the effects of adding the mean structure. This issue has not been examined in previous research. This study is based on the framework of Yung and Bentler (1999 and aims to examine the conditions that affect the recovery of weak factor loadings when the model includes the mean structure, compared to analyzing the covariance structure alone. A simulation study was conducted in which several constraints were defined for one-, two-, and three-factor models. Results show that adding the mean structure improves the recovery of weak factor loadings and reduces the asymptotic variances for the factor loadings, particularly for the models with a smaller number of factors and a small sample size. Therefore, under certain circumstances, modeling the means should be seriously considered for covariance models containing weak factor loadings.

  20. The Causal Factor Underlying the Correlation between Psychometric "g" and Scholastic Performance.

    Science.gov (United States)

    Luo, Dasen; Thompson, Lee A.; Detterman, Douglas K.

    2003-01-01

    Fitted structural equation models to covariances among 9 cognitive abilities Test variables, 11 intelligence test variables, and 3 achievement test scaled scores of 532 primary school children in a twin studies project. Results suggest that individual differences in mental speed are a main causal factor underlying correlation between general…

  1. Factors underlying male and female use of violent video games

    OpenAIRE

    Hartmann, T.; Möller, I.; Krause, C.

    2015-01-01

    Research has consistently shown that males play violent video games more frequently than females, but factors underlying this gender gap have not been examined to date. This approach examines the assumption that males play violent video games more because they anticipate more enjoyment and less guilt from engaging in virtual violence than females. This may be because males are less empathetic, tend to morally justify physical violence more and have a greater need for sensation and aggression ...

  2. A common genetic factor underlies hypertension and other cardiovascular disorders

    Directory of Open Access Journals (Sweden)

    Spector Tim D

    2004-11-01

    Full Text Available Abstract Background Certain conditions characterised by blood vessel occlusion or vascular spasm have been found to cluster together in epidemiological studies. However the biological causes for these associations remain controversial. This study used a classical twin design to examine whether these conditions are linked through shared environmental exposures or by a common underlying genetic propensity to vasospasm. Methods We investigated the association between hypertension, migraine, Raynaud's phenomenon and coronary artery disease in twins from a national register. Phenotype status was determined using a questionnaire and the genetic and environmental association between phenotypes was estimated through variance components analysis. Results Responses were obtained from 2,204 individuals comprising 525 monozygotic and 577 dizygotic pairs. There was a significant genetic contribution to all four traits with heritabilities ranging from 0.34 to 0.64. Multivariate model-fitting demonstrated that a single common genetic factor underlies the four conditions. Conclusions We have confirmed an association between hypertension, migraine, Raynaud's phenomenon and coronary artery disease, and shown that a single genetic factor underlies them. The demonstration of a shared genetic factor explains the association between them and adds weight to the theory of an inherited predisposition to vasospasm.

  3. Relativistic Effects on X-ray Structure Factors

    CERN Document Server

    Batke, Kilian

    2015-01-01

    X-ray structure factors from four-component molecular wave functions have been calculated for the model systems $M$(C$_2$H$_2$) ($M$= Ni, Pd, Pt). Relativistic effects on the structure factors are investigated by the comparison to results obtained from a non-relativistic reference and in order to systematically analyse the effect of different quasi-relativistic approximations, we also included the DKH2 and the ZORA Hamiltonian in our study. We show, that the overall effects of relativity on the structure factors on average amount to 0.47, 0.80 and 1.27% for the three model systems under investigation, but that for individual reflections or reflection series the effects can be orders of magnitude larger. Employing the DKH2 or ZORA Hamiltonian takes these effects into account to a large extend, reducing the according differences by one order of magnitude. In order to determine the experimental significance of the results, the magnitude of the relativistic effects on the structure factors is compared to the acco...

  4. Donation to disaster relief campaigns: underlying social cognitive factors exposed.

    Science.gov (United States)

    Oosterhof, Liesbeth; Heuvelman, Ard; Peters, Oscar

    2009-05-01

    A number of very serious natural disasters have put an enormous pressure on relief organizations in the last few years. The present study exposes underlying social cognitive factors for donation to relief campaigns. A causal model was constructed, based on social cognitive theory, research on attitudes, and the impact of media exposure. The aim was to expand and improve an already existing model by Cheung and Chan [Cheung, C. K., & Chan, C. M. (2000). Social-cognitive factors of donating money to charity, with special attention to an international relief organisation. Evaluation and Program Planning, 23, 241-253]. The expanded model showed a better fit. Furthermore, the expanded model explained two-thirds of the variance of the intention to donate to a disaster relief campaign. The greatest predictor of the intention to donate proved to be "Past donation to disaster relief campaigns." The factor "News exposure" was indicated to be a valuable additional factor, as it had a significant direct effect on "Awareness of a disaster relief campaign" and was the only factor that had a total effect on all other factors, including "Intention to donate to a disaster relief campaign."

  5. Effects of fundamental structure parameters on dynamic responses of submerged floating tunnel under hydrodynamic loads

    Institute of Scientific and Technical Information of China (English)

    Xu Long; Fei Ge; Lei Wang; Youshi Hong

    2009-01-01

    This paper investigates the effects of structure parameters on dynamic responses of submerged floating tunnel (SFT) under hydrodynamic loads. The structure parameters includes buoyancy-weight ratio (BWR), stiffness coefficients of the cable systems, tunnel net buoyancy and tunnel length. First, the importance of structural damp in relation to the dynamic responses of SFT is demonstrated and the mechanism of structural damp effect is discussed. Thereafter, the fundamental structure parameters are investi-gated through the analysis of SFT dynamic responses under hydrodynamic loads. The results indicate that the BWR of SFT is a key structure parameter. When BWR is 1.2, there is a remarkable trend change in the vertical dynamic response of SFT under hydrodynamic loads. The results also indicate that the ratio of the tunnel net buoyancy to the cable stiffness coefficient is not a characteristic factor affecting the dynamic responses of SFT under hydrodynamic loads.

  6. An empirical examination of the factor structure of compassion

    Science.gov (United States)

    Gu, Jenny; Cavanagh, Kate; Baer, Ruth

    2017-01-01

    Compassion has long been regarded as a core part of our humanity by contemplative traditions, and in recent years, it has received growing research interest. Following a recent review of existing conceptualisations, compassion has been defined as consisting of the following five elements: 1) recognising suffering, 2) understanding the universality of suffering in human experience, 3) feeling moved by the person suffering and emotionally connecting with their distress, 4) tolerating uncomfortable feelings aroused (e.g., fear, distress) so that we remain open to and accepting of the person suffering, and 5) acting or being motivated to act to alleviate suffering. As a prerequisite to developing a high quality compassion measure and furthering research in this field, the current study empirically investigated the factor structure of the five-element definition using a combination of existing and newly generated self-report items. This study consisted of three stages: a systematic consultation with experts to review items from existing self-report measures of compassion and generate additional items (Stage 1), exploratory factor analysis of items gathered from Stage 1 to identify the underlying structure of compassion (Stage 2), and confirmatory factor analysis to validate the identified factor structure (Stage 3). Findings showed preliminary empirical support for a five-factor structure of compassion consistent with the five-element definition. However, findings indicated that the ‘tolerating’ factor may be problematic and not a core aspect of compassion. This possibility requires further empirical testing. Limitations with items from included measures lead us to recommend against using these items collectively to assess compassion. Instead, we call for the development of a new self-report measure of compassion, using the five-element definition to guide item generation. We recommend including newly generated ‘tolerating’ items in the initial item pool, to

  7. Structural health management of aerospace hotspots under fatigue loading

    Science.gov (United States)

    Soni, Sunilkumar

    Sustainability and life-cycle assessments of aerospace systems, such as aircraft structures and propulsion systems, represent growing challenges in engineering. Hence, there has been an increasing demand in using structural health monitoring (SHM) techniques for continuous monitoring of these systems in an effort to improve safety and reduce maintenance costs. The current research is part of an ongoing multidisciplinary effort to develop a robust SHM framework resulting in improved models for damage-state awareness and life prediction, and enhancing capability of future aircraft systems. Lug joints, a typical structural hotspot, were chosen as the test article for the current study. The thesis focuses on integrated SHM techniques for damage detection and characterization in lug joints. Piezoelectric wafer sensors (PZTs) are used to generate guided Lamb waves as they can be easily used for onboard applications. Sensor placement in certain regions of a structural component is not feasible due to the inaccessibility of the area to be monitored. Therefore, a virtual sensing concept is introduced to acquire sensor data from finite element (FE) models. A full three dimensional FE analysis of lug joints with piezoelectric transducers, accounting for piezoelectrical-mechanical coupling, was performed in Abaqus and the sensor signals were simulated. These modeled sensors are called virtual sensors. A combination of real data from PZTs and virtual sensing data from FE analysis is used to monitor and detect fatigue damage in aluminum lug joints. Experiments were conducted on lug joints under fatigue loads and sensor signals collected were used to validate the simulated sensor response. An optimal sensor placement methodology for lug joints is developed based on a detection theory framework to maximize the detection rate and minimize the false alarm rate. The placement technique is such that the sensor features can be directly correlated to damage. The technique accounts for a

  8. Evidence for a heritable unidimensional symptom factor underlying obsessionality.

    Science.gov (United States)

    Mathews, Carol A; Greenwood, Tiffany; Wessel, Jennifer; Azzam, Amin; Garrido, Helena; Chavira, Denise A; Chandavarkar, Uma; Bagnarello, Monica; Stein, Murray; Schork, Nicholas J

    2008-09-05

    The division of obsessive-compulsive symptoms (OCS) into specific factors is now widely accepted. However, the utility of these categories for genetic studies remains unclear, as studies examining their heritability have been inconsistent. Less attention has been paid to the possibility that clinically significant obsessionality is primarily determined by a "core" group of OCS that crosses the boundaries between symptom subgroups. The aim of this study is to determine whether such a core group exists, and to compare its heritability to that of the more traditionally derived symptom factors. We examined the properties and heritability of obsessive-compulsive symptoms in college students, medical students, and obsessive-compulsive disorder (OCD) families using the Leyton Obsessional Inventory. In each of the three samples, we identified a core group of symptoms that comprised a single unique construct and accounted for over 90% of the variation of the four more traditional symptom factors. This core construct was highly correlated with OCD in our families and had a heritability estimate of 0.19 when OCD was not included as a covariate and 0.49 when OCD was included as a covariate. In contrast, the four symptom factors were not heritable. There appears to be an underlying unidimensional component to obsessionality, both in non-clinical and clinical samples. This component, which is heritable, accounts for the majority of the variation of the more traditionally derived symptom factors in our sample, and is composed of OCS that are not specific to any of the symptom subgroups.

  9. Seismic force modification factor for ductile structures

    Institute of Scientific and Technical Information of China (English)

    TONG Gen-shu; HUANG Jin-qiao

    2005-01-01

    The earthquake forces used in design codes of buildings should be theoretically determinable. This work examines the seismic force modification factor R based on elastic-plastic time-history earthquake analysis of SDOF systems, wherein the hysteresis models are elastic-perfectly-plastic (EPP), elastic-linearly-hardening (ELH), shear-slipped and bilinear-elastic. The latter two models are analysed for separating the effect of the ductility and the energy-dissipating capacity. Three-hundred eighty-eight earthquake records from different site conditions are used in analysis. The ductility is taken to be 2, 3, 4, 5 and 6, with the damping ratio being 0.02, 0.035 and 0.05 respectively. The post-yield stiffness ratios 0.0, 0.1 and 0.2 are used in the analysis. The R spectra are standardized by the characteristic period of the earthquake records, which leads to a much smaller scatter in averaged numerical results. It was found that the most important factor determining R is the ductility. R increases more than linearly with ductility. The energy-dissipating capacity, damping and the post-yield stiffness are the less important factors. The energy dissipating capacity is important only for structures with short period and moderate period (0.3≤T/Tg<5.0). For EPP and ELH models, R for 0.05 damping is 10% to 15% smaller than for 0.02 damping. For EPP and ELH models, greater post-yield stiffness leads to greater R, but the influence of post-yield stiffness is obvious only when the post-yield stiffness is less than 10% of the initial stiffness. By means of statistical regression analysis the relation of the seismic force modification factor R with the natural period of the system and ductility for EPP and ELH models were established for each site and soil condition.

  10. Liquid Water Structure from Anomalous Density under Ambient Condition

    Institute of Scientific and Technical Information of China (English)

    SUN Qiang; ZHENG Hai-Fei

    2006-01-01

    @@ From discussion of the structure of liquid water, we deduce that water under ambient condition is mainly composed of ice Ih-like molecular clusters and clathrate-like molecular clusters. The water molecular clusters remain in a state of chemical equilibrium (reversible clustering reactions). This structural model can be demonstrated by quantitative study on anomalous density with increasing temperature at ambient pressure.

  11. Personality factors underlying suicidal behavior among military youth.

    Science.gov (United States)

    Soltaninejad, Abdollah; Fathi-Ashtiani, Ali; Ahmadi, Khodabakhsh; Mirsharafoddini, Hediye Sadat; Nikmorad, Alireza; Pilevarzadeh, Motahare

    2014-04-01

    Suicidal behavior is one the most significant mental health problems in the military. Militaries are closed systems that operate in particular situations. Military service is associated with certain stressful conditions. On this basis, there is likely of trauma in the military environment. Measures of suicidal behavior are pathologically complex. A range of biological, psychological, social, and institutional factors are involved in the incidence and prevalence of these behaviors. One of the underlying factors in suicidal behavior is individuals' personality. The study population comprised of the Iranian Armed Forces. To recruit the sample of the research, 1659 soldiers were selected by multistage sampling. Data were collected using the Beck Scale for Suicide Ideation (BSSI) and NEO-Five Factor Inventory. There was a significant positive correlation (r = 0.323) between neuroticism and suicide ideation; however, significant negative correlations existed between three other personality traits --extraversion [r = -0.306], agreeableness [r = -0.227], and conscientiousness [r = -0.271] and suicidal ideation. Unlike neuroticism, extraversion and conscientiousness personality factors could reduce significantly (as much 14% as are predicted) levels of suicidal ideation. Based on these results, neuroticism might increase suicide, but extraversion and conscientiousness personality traits are associated with a reduced risk of suicide.

  12. Personality Factors Underlying Suicidal Behavior Among Military Youth

    Science.gov (United States)

    Soltaninejad, Abdollah; Fathi-Ashtiani, Ali; Ahmadi, Khodabakhsh; Mirsharafoddini, Hediye Sadat; Nikmorad, Alireza; Pilevarzadeh, Motahare

    2014-01-01

    Background: Suicidal behavior is one the most significant mental health problems in the military. Militaries are closed systems that operate in particular situations. Military service is associated with certain stressful conditions. On this basis, there is likely of trauma in the military environment. Measures of suicidal behavior are pathologically complex. A range of biological, psychological, social, and institutional factors are involved in the incidence and prevalence of these behaviors. Objectives: One of the underlying factors in suicidal behavior is individuals' personality. Patients and Methods: The study population comprised of the Iranian Armed Forces. To recruit the sample of the research, 1659 soldiers were selected by multistage sampling. Data were collected using the Beck Scale for Suicide Ideation (BSSI) and NEO-Five Factor Inventory. Results: There was a significant positive correlation (r = 0.323) between neuroticism and suicide ideation; however, significant negative correlations existed between three other personality traits --extraversion [r = -0.306], agreeableness [r = -0.227], and conscientiousness [r = -0.271] and suicidal ideation. Unlike neuroticism, extraversion and conscientiousness personality factors could reduce significantly (as much 14% as are predicted) levels of suicidal ideation. Conclusions: Based on these results, neuroticism might increase suicide, but extraversion and conscientiousness personality traits are associated with a reduced risk of suicide. PMID:24910793

  13. Transcription factors expressed in soybean roots under drought stress.

    Science.gov (United States)

    Pereira, S S; Guimarães, F C M; Carvalho, J F C; Stolf-Moreira, R; Oliveira, M C N; Rolla, A A P; Farias, J R B; Neumaier, N; Nepomuceno, A L

    2011-10-21

    To gain insight into stress-responsive gene regulation in soybean plants, we identified consensus sequences that could categorize the transcription factors MYBJ7, BZIP50, C2H2, and NAC2 as members of the gene families myb, bzip, c2h2, and nac, respectively. We also investigated the evolutionary relationship of these transcription factors and analyzed their expression levels under drought stress. The NCBI software was used to find the predicted amino acid sequences of the transcription factors, and the Clustal X software was used to align soybean and other plant species sequences. Phylogenetic trees were built using the Mega 4.1 software by neighbor joining and the degree of confidence test by Bootstrap. Expression level studies were carried out using hydroponic culture; the experiments were designed in completely randomized blocks with three repetitions. The blocks consisted of two genotypes, MG/BR46 Conquista (drought-tolerant) and BR16 (drought-sensitive) and the treatments consisted of increasingly long dehydration periods (0, 25, 50, 75, and 100 min). The transcription factors presented domains and/or conserved regions that characterized them as belonging to the bzip, c2h2, myb, and nac families. Based on the phylogenetic trees, it was found that the myb, bzip and nac genes are closely related to myb78, bzip48 and nac2 of soybean and that c2h2 is closely related to c2h2 of Brassica napus. Expression of all genes was in general increased under drought stress in both genotypes. Major differences between genotypes were due to the lowering of the expression of the mybj7 and c2h2 genes in the drought-tolerant variety at some times. Over-expression or silencing of some of these genes has the potential to increase stress tolerance.

  14. Why are you draining your brain? Factors underlying decisions of graduating Lebanese medical students to migrate.

    Science.gov (United States)

    Akl, Elie A; Maroun, Nancy; Major, Stella; Afif, Claude; Chahoud, Bechara; Choucair, Jacques; Sakr, Mazen; Schünemann, Holger J

    2007-03-01

    In the context of a worldwide physician brain drain phenomenon, Lebanon has the highest emigration factor in the Middle East and North Africa. In this manuscript we aim to identify and develop a conceptual framework for the factors underlying the decisions of graduating Lebanese medical students to train abroad. We conducted two focus groups and seven semi-structured individual interviews with 23 students. In the deductive analysis (based on the push-pull theory), students reported push factors in Lebanon and pull factors abroad related to five dimensions. They focused predominantly on how training abroad provides them with a competitive advantage in an oversaturated Lebanese job market. An inductive analysis revealed the following emerging concepts: repel factors abroad and retain factors locally; societal expectations that students should train abroad; marketing of abroad training; and an established culture of migration. The marketing of abroad training and the culture of migration are prevalent in the academic institutions.

  15. Local zeta factors and geometries under Spec Z

    Science.gov (United States)

    Manin, Yu I.

    2016-08-01

    The first part of this note shows that the odd-period polynomial of each Hecke cusp eigenform for the full modular group produces via the Rodriguez-Villegas transform ([1]) a polynomial satisfying the functional equation of zeta type and having non-trivial zeros only in the middle line of its critical strip. The second part discusses the Chebyshev lambda-structure of the polynomial ring as Borger's descent data to \\mathbf{F}_1 and suggests its role in a possible relation of the Γ\\mathbf{R}-factor to 'real geometry over \\mathbf{F}_1' (cf. [2]).

  16. How social structure changes in Chinese global cities: Synthesizing globalization, migration and institutional factors in Beijing

    NARCIS (Netherlands)

    Shi, Q.; Liu, T.; Musterd, S.; Cao, G.

    2017-01-01

    Recent studies on the social structural change in global cities have recognized globalization, migration, and institutional factors as three main forces underlying this process. However, effects of these factors have rarely been synthetically examined and the social structure of emerging Chinese

  17. Condition assessment of structures under unknown support excitation

    Institute of Scientific and Technical Information of China (English)

    Zhang Kun; S. S. Law; Duan Zhongdong

    2009-01-01

    A new method is proposed to assess the condition of structures under unknown support excitation by simultaneously detecting local damage and identifying the support excitation from several structural dynamic responses. The support excitation acting on a structure is modeled by orthogonal polynomial approximations, and the sensitivities of structural dynamic response with respect to its physical parameters and orthogonal coefficients are derived. The identification equation is based on Taylor's first order approximation, and is solved with the damped least-squares method in an iterative procedure. A fifteen-story shear building model and a five-story three-dimensional steel frame structure are studied to validate the proposed method. Numerical simulations with noisy measured accelerations show that the proposed method can accurately detect local damage and identify unknown support excitation from only several responses of the structure. This method provides a new approach for detecting structural damage and updating models with unknown input and incomplete measured output information.

  18. Providing stability of properties of filled polymers under the joint effect of exploitation factors

    Science.gov (United States)

    Minakova, N. N.; Ushakov, V. Ya.

    2016-11-01

    The present work is devoted to a search for the structural parameter that can be used to adjust the structure of a resistive polymer composite material stable against the action of exploitation factors. The objects of research are polymers filled with technical carbon. Various approaches have been developed for them to control the stability of their properties: application of polymers of different chemical compositions and electroconductive filler with different concentrations, grades, and surface modifications. The following main problems have been formulated: based on an analysis of physical structurization processes, to reveal geometrical parameters determining the stability of properties under the joint effect of the exploitation factors; to adjust the structural parameter that responds to these factors; to check its efficiency; to estimate the importance of factors that influence the stability of the properties; and to propose an approach to the adjustment of the main material components to provide the stability of properties under the effect of the exploitation factors. The structural parameter was adjusted based on the physical principles developed earlier by the authors of the present report and other authors, whose publications are given in the References. It has been established that the stability of properties to the joint influence of the exploitation factors can be determined by the structural parameter that responds to branching of the electroconductive grid in a comparative analysis of the known material and the material being synthesized. Its application allows the problem of adjusting the material components to be also solved in the case in which identical values of the specific volume electrical resistances are formed for different elemental compositions.

  19. CO2 ice structure and density under Martian atmospheric conditions

    Science.gov (United States)

    Mangan, T. P.; Salzmann, C. G.; Plane, J. M. C.; Murray, B. J.

    2017-09-01

    Clouds composed of CO2 ice form throughout the Martian atmosphere. In the mesosphere, CO2 ice clouds are thought to form via heterogeneous ice nucleation on nanoparticles of meteoric origin at temperatures often below 100 K. Lower altitude CO2 ice clouds in the wintertime polar regions form up to around 145 K and lead to the build-up of the polar ice caps. However, the crystal structure and related fundamental properties of CO2 ice under Martian conditions are poorly characterised. Here we present X-ray diffraction (XRD) measurements of CO2 ice, grown via deposition from the vapour phase under temperature and pressure conditions analogous to the Martian mesosphere. A crystalline cubic structure was determined, consistent with the low-pressure polymorph (CO2-I, space group Pa-3 (No. 205)). CO2 deposited at temperatures of 80-130 K and pressures of 0.01-1 mbar was consistent with dry ice and previous literature measurements, thus removing the possibility of a more complicated phase diagram for CO2 in this region. At 80 K, a lattice parameter of 5.578 ± 0.002 Å, cell volume of 173.554 ± 0.19 Å3 and density of 1.684 ± 0.002 g cm-3 was determined. Using these measurements, we determined the thermal expansion of CO2 across 80-130 K that allowed for a fit of CO2 ice density measurements across a larger temperature range (80-195 K) when combined with literature data (CO2 density = 1.72391 - 2.53 × 10-4T - 2.87 × 10-6 T2). Temperature-dependent CO2 density values are used to estimate sedimentation velocities and heterogeneous ice nucleation rates, showing an increase in nucleation rate of up to a factor of 1000 when compared to commonly used literature values. This temperature-dependent equation of state is therefore suggested for use in future studies of Martian mesospheric CO2 clouds. Finally, we discuss the possible shapes of crystals of CO2 ice in the Martian atmosphere and show that a range of shapes including cubes and octahedra as well as a combination of the

  20. Algorithms for Determining Physical Responses of Structures Under Load

    Science.gov (United States)

    Richards, W. Lance; Ko, William L.

    2012-01-01

    Ultra-efficient real-time structural monitoring algorithms have been developed to provide extensive information about the physical response of structures under load. These algorithms are driven by actual strain data to measure accurately local strains at multiple locations on the surface of a structure. Through a single point load calibration test, these structural strains are then used to calculate key physical properties of the structure at each measurement location. Such properties include the structure s flexural rigidity (the product of the structure's modulus of elasticity, and its moment of inertia) and the section modulus (the moment of inertia divided by the structure s half-depth). The resulting structural properties at each location can be used to determine the structure s bending moment, shear, and structural loads in real time while the structure is in service. The amount of structural information can be maximized through the use of highly multiplexed fiber Bragg grating technology using optical time domain reflectometry and optical frequency domain reflectometry, which can provide a local strain measurement every 10 mm on a single hair-sized optical fiber. Since local strain is used as input to the algorithms, this system serves multiple purposes of measuring strains and displacements, as well as determining structural bending moment, shear, and loads for assessing real-time structural health. The first step is to install a series of strain sensors on the structure s surface in such a way as to measure bending strains at desired locations. The next step is to perform a simple ground test calibration. For a beam of length l (see example), discretized into n sections and subjected to a tip load of P that places the beam in bending, the flexural rigidity of the beam can be experimentally determined at each measurement location x. The bending moment at each station can then be determined for any general set of loads applied during operation.

  1. Numerical Analysis of Vibrations of Structures under Moving Inertial Load

    CERN Document Server

    Bajer, Czeslaw I

    2012-01-01

    Moving inertial loads are applied to structures in civil engineering, robotics, and mechanical engineering. Some fundamental books exist, as well as thousands of research papers. Well known is the book by L. Frýba, Vibrations of Solids and Structures Under Moving Loads, which describes almost all problems concerning non-inertial loads. This book presents broad description of numerical tools successfully applied to structural dynamic analysis. Physically we deal with non-conservative systems. The discrete approach formulated with the use of the classical finite element method results in elemental matrices, which can be directly added to global structure matrices. A more general approach is carried out with the space-time finite element method. In such a case, a trajectory of the moving concentrated parameter in space and time can be simply defined. We consider structures described by pure hyperbolic differential equations such as strings and structures described by hyperbolic-parabolic differential equations ...

  2. Gravitational form factors and nucleon spin structure

    Science.gov (United States)

    Teryaev, O. V.

    2016-10-01

    Nucleon scattering by the classical gravitational field is described by the gravitational (energy-momentum tensor) form factors (GFFs), which also control the partition of nucleon spin between the total angular momenta of quarks and gluons. The equivalence principle (EP) for spin dynamics results in the identically zero anomalous gravitomagnetic moment, which is the straightforward analog of its electromagnetic counterpart. The extended EP (ExEP) describes its (approximate) validity separately for quarks and gluons and, in turn, results in equal partition of the momentum and total angular momentum. It is violated in quantum electrodynamics and perturbative quantum chromodynamics (QCD), but may be restored in nonperturbative QCD because of confinement and spontaneous chiral symmetry breaking, which is supported by models and lattice QCD calculations. It may, in principle, be checked by extracting the generalized parton distributions from hard exclusive processes. The EP for spin-1 hadrons is also manifested in inclusive processes (deep inelastic scattering and the Drell-Yan process) in sum rules for tensor structure functions and parton distributions. The ExEP may originate in either gravity-proof confinement or in the closeness of the GFF to its asymptotic values in relation to the mediocrity principle. The GFFs in time-like regions reveal some similarity between inflation and annihilation.

  3. Structural integration in hypoxia-inducible factors

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dalei; Potluri, Nalini; Lu, Jingping; Kim, Youngchang; Rastinejad, Fraydoon

    2015-08-20

    The hypoxia-inducible factors (HIFs) coordinate cellular adaptations to low oxygen stress by regulating transcriptional programs in erythropoiesis, angiogenesis and metabolism. These programs promote the growth and progression of many tumours, making HIFs attractive anticancer targets. Transcriptionally active HIFs consist of HIF-alpha and ARNT (also called HIF-1 beta) subunits. Here we describe crystal structures for each of mouse HIF-2 alpha-ARNT and HIF-1 alpha-ARNT heterodimers in states that include bound small molecules and their hypoxia response element. A highly integrated quaternary architecture is shared by HIF-2 alpha-ARNT and HIF-1 alpha-ARNT, wherein ARNT spirals around the outside of each HIF-alpha subunit. Five distinct pockets are observed that permit small-molecule binding, including PAS domain encapsulated sites and an interfacial cavity formed through subunit heterodimerization. The DNA-reading head rotates, extends and cooperates with a distal PAS domain to bind hypoxia response elements. HIF-alpha mutations linked to human cancers map to sensitive sites that establish DNA binding and the stability of PAS domains and pockets.

  4. A PRELIMINARY STUDY OF EXPERT SYSTEM FOR MINING UNDER STRUCTURES

    Institute of Scientific and Technical Information of China (English)

    吴侃; 何国清; 曹立明

    1991-01-01

    The expert system MUST (Mining Under Structures) shown in this paper and established by the authors is a preliminary expert system to solve the policy-making problems formining under structures by means of computers instead of humanbeing. Based on the experience of relative experts,the authors established a knowledge base about the minings under structures ,researched into reasonable method to simulate thinking processes of human experts when they are solvin8 the problems, established the network of an expert system and named it'MUST system'MUST system uses the method of the structural system analysis approach. A kind of methods of Turbo Prolog and Fortran 77 language alternations is designed to meet the needs of exchange information within the MUST system. Based on this kind of methods MUST system has been constructed and realised on IBM-PC computer. For verifying the correctness. suitability and reliablity of MUST system,some practical examples of minings under structures were tentatively solved using MUST system ,whose results are satisfactory.

  5. Fibroblast Growth Factors and Vascular Endothelial Growth Factor Promote Cardiac Reprogramming under Defined Conditions

    Directory of Open Access Journals (Sweden)

    Hiroyuki Yamakawa

    2015-12-01

    Full Text Available Fibroblasts can be directly reprogrammed into cardiomyocyte-like cells (iCMs by overexpression of cardiac transcription factors, including Gata4, Mef2c, and Tbx5; however, this process is inefficient under serum-based culture conditions, in which conversion of partially reprogrammed cells into fully reprogrammed functional iCMs has been a major hurdle. Here, we report that a combination of fibroblast growth factor (FGF 2, FGF10, and vascular endothelial growth factor (VEGF, termed FFV, promoted cardiac reprogramming under defined serum-free conditions, increasing spontaneously beating iCMs by 100-fold compared with those under conventional serum-based conditions. Mechanistically, FFV activated multiple cardiac transcriptional regulators and converted partially reprogrammed cells into functional iCMs through the p38 mitogen-activated protein kinase and phosphoinositol 3-kinase/AKT pathways. Moreover, FFV enabled cardiac reprogramming with only Mef2c and Tbx5 through the induction of cardiac reprogramming factors, including Gata4. Thus, defined culture conditions promoted the quality of cardiac reprogramming, and this finding provides new insight into the mechanism of cardiac reprogramming.

  6. Structural Factors Affecting Health Examination Behavioral Intention

    National Research Council Canada - National Science Library

    Huang, Hui-Ting; Kuo, Yu-Ming; Wang, Shiang-Ru; Wang, Chia-Fen; Tsai, Chung-Hung

    2016-01-01

    .... Here, we used the health belief model as a foundation and integrated social psychological factors and investigated the factors influencing health examination behavioral intention among the public in Taiwan...

  7. Characterizing Thematized Derivative Schema by the Underlying Emergent Structures

    Science.gov (United States)

    Garcia, Mercedes; Llinares, Salvador; Sanchez-Matamoros, Gloria

    2011-01-01

    This paper reports on different underlying structures of the derivative schema of three undergraduate students that were considered to be at the trans level of development of the derivative schema (action-process-object-schema). The derivative schema is characterized in terms of the students' ability to explicitly transfer the relationship between…

  8. Swimming and asthma: factors underlying respiratory symptoms in competitive swimmers.

    Science.gov (United States)

    Päivinen, Marja Kristiina; Keskinen, Kari Lasse; Tikkanen, Heikki Olavi

    2010-04-01

    Swimming is recommended for asthmatics. However, many competitive swimmers report asthmatic symptoms. While some studies identify the swimming environment as a trigger for allergy and asthmatic symptoms, even more studies suggest swimming to be suitable for people with allergies and asthma. The factors behind the symptoms were studied first by determining the prevalence of asthma, allergy and self-reported asthmatic symptoms in experienced Finnish swimmers and then by examining the relationships between the reported symptoms and the main triggering factors: medical history, environment and exercise intensity. Top swimmers (n = 332) of the Finnish Swimming Association registry (N = 4578) were asked to complete a structured questionnaire on their medical history, swimming background, swimming environment and symptoms in different swimming intensities. Two hundred experienced swimmers, 107 females and 93 males, with an average age of 18.5 [standard deviation (SD) = 3.0] years and a swimming training history of 9 (SD = 3.8) years completed the questionnaire. Physician-diagnosed asthma was reported by 32 swimmers (16%), including 24 (12%) with exercise-induced asthma. Physician-diagnosed allergy was reported by 81 (41%) swimmers. Asthmatic symptoms during swimming were described by 84 subjects (42%). Most symptoms occurred when swimming exceeded speeds corresponding to the lactic/anaerobic threshold. Family history of asthma was significant and the most important risk factor for asthmatic symptoms. The prevalence of asthma in swimmers was higher than in the general population but not different from that in other endurance athletes. Family history of asthma and increased swimming intensity had the strongest associations with the reported asthmatic symptoms.

  9. Structural phase transitions in boron carbide under stress

    Science.gov (United States)

    Korotaev, P.; Pokatashkin, P.; Yanilkin, A.

    2016-01-01

    Structural transitions in boron carbide B4C under stress were studied by means of first-principles molecular dynamics in the framework of density functional theory. The behavior depends strongly on degree of non-hydrostatic stress. Under hydrostatic stress continuous bending of the three-atom C-B-C chain was observed up to 70 GPa. The presence of non-hydrostatic stress activates abrupt reversible chain bending, which is displacement of the central boron atom in the chain with the formation of weak bonds between this atom and atoms in the nearby icosahedra. Such structural change can describe a possible reversible phase transition in dynamical loading experiments. High non-hydrostatic stress achieved in uniaxial loading leads to disordering of the initial structure. The formation of carbon chains is observed as one possible transition route.

  10. INVESTIGATING THE FACTOR STRUCTURE OF THE BLOG ATTITUDE SCALE

    Directory of Open Access Journals (Sweden)

    Zahra SHAHSAVAR

    2010-10-01

    Full Text Available Due to the wide application of advanced technology in education, many attitude scales have been developed to evaluate learners’ attitudes toward educational tools. However, with the rapid development of emerging technologies, using blogs as one of the Web 2.0 tools is still in its infancy and few blog attitude scales have been developed yet. In view of this need, a lot of researchers like to design a new scale based on their conceptual and theoretical framework of their own study rather than using available scales. The present study reports the design and development of a blog attitude scale (BAS. The researchers developed a pool of items to capture the complexity of the blog attitude trait, selected 29 items in the content analysis, and assigned the scale comprising 29 items to 216 undergraduate students to explore the underlying structure of the BAS. In exploratory factor analysis, three factors were discovered: blog anxiety, blog desirability, and blog self-efficacy; 14 items were excluded. The extracted items were subjected to a confirmatory factor analysis which lent further support to the BAS underpinning structure.

  11. Comparing the factor structure of the Wisconsin Schizotypy Scales and the Schizotypal Personality Questionnaire.

    Science.gov (United States)

    Gross, Georgina M; Mellin, Juliann; Silvia, Paul J; Barrantes-Vidal, Neus; Kwapil, Thomas R

    2014-10-01

    Schizotypy is a multidimensional construct that captures the expression of schizophrenic symptoms and impairment from subclinical levels to full-blown psychosis. The present study examined the comparability of the factor structure of 2 leading psychometric measures of schizotypy: the Wisconsin Schizotypy Scales (WSS) and the Schizotypal Personality Questionnaire (SPQ). Both the SPQ and WSS purportedly capture the multidimensional structure of schizotypy; however, whether they are measuring comparable factors has not been empirically demonstrated. This study provided support for a 2-factor model with positive and negative factors underlying the WSS; however, contrary to previous findings, the best fit for the SPQ was for a 4-factor model using confirmatory factor analysis, and a 2-factor model using exploratory factor analysis. The WSS factors were relatively distinct, whereas those underlying the SPQ showed high overlap. The WSS positive and SPQ cognitive-perceptual factors appeared to tap comparable constructs. However, the WSS negative and SPQ interpersonal factors appeared to tap somewhat different constructs based on their correlation and their patterns of associations with other schizotypy dimensions and the Five-Factor Model-suggesting that the SPQ interpersonal factor may not adequately tap negative or deficit schizotypy. Although the SPQ offers the advantage over the WSS of having a disorganization factor, it is not clear that this SPQ factor is actually distinct from positive schizotypy. Existing measures should be used with caution and new measures based on a priori theories are necessary to further understand the factor structure of schizotypy.

  12. Employee motivation in Ghana: A factor structure and measurement tool

    Directory of Open Access Journals (Sweden)

    B. B. Puplampu

    2007-12-01

    Full Text Available Purpose: This paper reports research on the factor structure of employee motivation as well as provides a tool for measuring the level of employee motivation in Ghanaian organisations. Methodology: The study was designed as exploratory, comparative and cross-sectional. 260 respondents drawn from across the gender, status and job grade hierarchy of 19 organisations participated. The organisations were matched in terms of tenure (over 5years, number of employees (50 or more and geographic location (headquartered in Accra. A 41-item questionnaire on the Level of Motivation (LoM; Characteristics of Employee Motivation (CEM; aspects of Organisational Citizenship Behaviour (OCB; Managerial Assumptions about employee behaviour (MA; Contextual Institutional Analysis (IAN and Organisational Leadership Issues (Le was developed and used. The instrument combined fixed response format on a 3-point scale with open-ended responses. Findings: Exploratory Factor Analyses (Varimax Rotation, converging in 26 iterations yielded 6 factors, which account for 60% of the variance. Thematic analyses of both interview and open-ended questionnaire data support the emergent factor structure, providing some tentative indication that employee motivation in the Ghanaian (or indeed African context should be looked at more in an integrated manner rather than in terms of the limiting confines of any one theory of motivation. The 3 items hypothesised to constitute the measure of level of employee motivation loaded neatly onto Factor 6. One-way ANOVA demonstrated no differences in the level of motivation across the organisational samples; this was confirmed by the interview data. Implications/Originality/Value: The implications and value of this research are: that motivation research in Africa does need to focus more on developing an integrated model of employee motivation; also, a simple 3-item but novel tool for measuring the level of employee motivation as well as its

  13. Study on the Characteristic Energy Factor of the Deep Rock Mass Under Weak Disturbance

    Science.gov (United States)

    Wang, Mingyang; Li, Jie; Ma, Linjian; Huang, Houxu

    2016-08-01

    This study aims to investigate the characteristic energy factor of the deep rock mass deformation subjected to the disturbance induced by excavation or explosion. Based on the well-known rock hierarchical structure, the equivalent average kinetic energy of the deep rock mass under weak disturbance is first introduced. The characteristic energy factor that reflects the instable deformation of the deep rock mass is derived using the principle of variation. The relationship between the characteristic energy factor and the energy hierarchical sequence of the deep rock mass deformation and failure has also been illustrated. We believe that the characteristic energy factor is closely related to the characteristic scientific phenomena of deep rock mass in essence, which can provide a new approach for the study of deep rock mass in the fields of nonlinear mechanics, statistic physical mechanics, and mechanics of explosion and geophysics.

  14. Structure formation of surfactant membranes under shear flow

    Science.gov (United States)

    Shiba, Hayato; Noguchi, Hiroshi; Gompper, Gerhard

    2013-07-01

    Shear-flow-induced structure formation in surfactant-water mixtures is investigated numerically using a meshless-membrane model in combination with a particle-based hydrodynamics simulation approach for the solvent. At low shear rates, uni-lamellar vesicles and planar lamellae structures are formed at small and large membrane volume fractions, respectively. At high shear rates, lamellar states exhibit an undulation instability, leading to rolled or cylindrical membrane shapes oriented in the flow direction. The spatial symmetry and structure factor of this rolled state agree with those of intermediate states during lamellar-to-onion transition measured by time-resolved scatting experiments. Structural evolution in time exhibits a moderate dependence on the initial condition.

  15. The Fatigue Behavior of Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    2009-01-01

    of the investigation, fatigue test series with a total of 540 fatigue tests have been carried through on various types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel or high-strength steel. The fatigue tests......Fatigue damage accumulation in steel structures under random loading has been studied in a number of investigations at the Technical University of Denmark. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part...... and the fracture mechanics analyses have been carried out using load histories, which are realistic in relation to the types of structures studied, i.e. primarily bridges, offshore structures and chimneys. In general, the test series carried through show a significant difference between constant amplitude...

  16. The Fatigue Behavior of Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    2008-01-01

    of the investigation, fatigue test series with a total of 540 fatigue tests have been carried through on various types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel or high-strength steel. The fatigue tests......Fatigue damage accumulation in steel structures under random loading has been studied in a number of investigations at the Technical University of Denmark. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part...... and the fracture mechanics analyses have been carried out using load histories, which are realistic in relation to the types of structures studied, i.e. primarily bridges, offshore structures and chimneys. In general, the test series carried through show a significant difference between constant amplitude...

  17. Interferometric correlator for acoustic radiation and underlying structural vibration

    Science.gov (United States)

    Apostol, Adela; Kilpatrick, James; Markov, Vladimir; Bendiksen, Oddvar O.

    2016-12-01

    In this paper we discuss the background and principles of an optical non-contact sensor fusion concept, the Interferometric Correlator for Acoustic Radiation and Underlying Structural Vibration (ICARUSV) and give practical example of its capabilities, focusing on its ability to simultaneously capture, visualize and quantitatively characterize full-field non-stationary structural dynamics and unsteady radiated sound fields or transient flow fields around the structure of interest. The ICARUSV's multi-sensor design is based on a parallel architecture and therefore the data capture is fast and inherently support a wide variety of spatio-temporal or spatio-spectral analysis methods which characterize the structural or acoustic/flow field dynamics as it occurs in real time, including short-lived transient events. No other technology available today offers this level of multi-parameter multi-dimensional data1.

  18. Factor structure of social fears: The Liebowitz Social Anxiety Scale.

    Science.gov (United States)

    Safren, S A; Heimberg, R G; Horner, K J; Juster, H R; Schneier, F R; Liebowitz, M R

    1999-01-01

    In the assessment of social anxiety, investigators often differentiate between social interactional anxiety and performance anxiety. The Liebowitz Social Anxiety Scale (LSAS), a clinician-administered measure of social anxiety and avoidance, was originally developed with separate subscales for the assessment of fear and avoidance of situations involving social interaction and performance/observation by others. Separate confirmatory factor analyses of the LSAS fear and avoidance ratings demonstrated that this two-factor model did not provide an adequate fit to the data, suggesting the need to further investigate the underlying structure of the LSAS. Separate exploratory common factor analyses of the fear and avoidance ratings yielded four similar factors for each: (1) social interaction, (2) public speaking, (3) observation by others, and (4) eating and drinking in public, which demonstrated convergent and discriminant validity with other measures of social anxiety. These findings suggest that there are four global categories of social fear assessed by the LSAS, and that while social interaction anxiety appears to be unifactorial, fear of performance/observation situations may be multifactorial.

  19. Factor Structure of the Exercise Self-Efficacy Scale

    Science.gov (United States)

    Cornick, Jessica E.

    2015-01-01

    The current study utilized exercise self-efficacy ratings from undergraduate students to assess the factor structure of the Self-Efficacy to Regulate Exercise Scale (Bandura, 1997, 2006). An exploratory factor analysis (n = 759) indicated a two-factor model solution and three separate confirmatory factor analyses (n = 1,798) supported this…

  20. Generalized Minimum Variance Control for MDOF Structures under Earthquake Excitation

    Directory of Open Access Journals (Sweden)

    Lakhdar Guenfaf

    2016-01-01

    Full Text Available Control of a multi-degree-of-freedom structural system under earthquake excitation is investigated in this paper. The control approach based on the Generalized Minimum Variance (GMV algorithm is developed and presented. Our approach is a generalization to multivariable systems of the GMV strategy designed initially for single-input-single-output (SISO systems. Kanai-Tajimi and Clough-Penzien models are used to generate the seismic excitations. Those models are calculated using the specific soil parameters. Simulation tests using a 3DOF structure are performed and show the effectiveness of the control method.

  1. Volatility transmission among Latin American stock markets under structural breaks

    Science.gov (United States)

    Güloğlu, Bülent; Kaya, Pınar; Aydemir, Resul

    2016-11-01

    The paper investigates the volatility spillovers among five major Latin American (LA) stock markets under the presence of the structural breaks in variance. We employ a multivariate dynamic conditional correlation (DCC GARCH) model allowing for structural breaks in variance. The dynamic correlations show that volatility spillover effects among the markets are not strong. Causality in mean tests indicate one way causality from BOVESPA to all markets, whereas causality in variance tests indicate one way causality only from BOVESPA to IPSA. These findings suggest that while the markets in the sample are interdependent, there is not enough statistical evidence to infer the contagion effects among the markets.

  2. Examining the factor structure of the Multiple Sclerosis Impact Scale.

    Science.gov (United States)

    Fitzgerald, Shawn M; Li, Jian; Rumrill, Phillip D; Merchant, William; Bishop, Malachy

    2014-01-01

    The purpose of this study was to investigate the factor structure of the Multiple Sclerosis Impact Scale (MSIS-29) to assess its suitability for modeling the impact of MS on a nation-wide sample of individuals from the United States. Investigators completed a Confirmatory Factor Analysis (CFA) to examine the two-factor structure proposed by Hobart et al. [17]. Although the original MSIS-29 factor structure did not fit the data exactly, the hypothesized two-factor model was partially supported in the current data. Implications for future instrument development and rehabilitation practice are discussed.

  3. Investigating the Underlying Factors of Corruption in the Public Construction Sector: Evidence from China.

    Science.gov (United States)

    Shan, Ming; Le, Yun; Yiu, Kenneth T W; Chan, Albert P C; Hu, Yi

    2016-12-30

    Over recent years, the issue of corruption in the public construction sector has attracted increasing attention from both practitioners and researchers worldwide. However, limited efforts are available for investigating the underlying factors of corruption in this sector. Thus, this study attempted to bridge this knowledge gap by exploring the underlying factors of corruption in the public construction sector of China. To achieve this goal, a total of 14 structured interviews were first carried out, and a questionnaire survey was then administered to 188 professionals in China. Two iterations of multivariate analysis approaches, namely, stepwise multiple regression analysis and partial least squares structural equation modeling were successively utilized to analyze the collected data. In addition, a case study was also conducted to triangulate the findings obtained from the statistical analysis. The results generated from these three research methods achieve the same conclusion: the most influential underlying factor leading to corruption was immorality, followed by opacity, unfairness, procedural violation, and contractual violation. This study has contributed to the body of knowledge by exploring the properties of corruption in the public construction sector. The findings from this study are also valuable to the construction authorities as they can assist in developing more effective anti-corruption strategies.

  4. Three-dimensional vortex structures under breaking waves

    OpenAIRE

    WATANABE Yasunori; Saeki, Hiroshi; Hosking, Roger J.

    2005-01-01

    The large-scale vortex structures under spilling and plunging breakers are investigated, using a fully three-dimensional large-eddy simulation (LES). When an overturning jet projecting from the crest in a breaking wave rebounds from the water surface ahead, the vorticity becomes unstable in a saddle region of strain between the rebounding jet and a primary spanwise vortex, resulting in spanwise undulations of the vorticity. The undulations are amplified on a braid in this saddle region, leadi...

  5. Elasticity, structure, and relaxation of extended proteins under force

    OpenAIRE

    2013-01-01

    Force spectroscopies have emerged as a powerful and unprecedented tool to study and manipulate biomolecules directly at a molecular level. Usually, protein and DNA behavior under force is described within the framework of the worm-like chain (WLC) model for polymer elasticity. Although it has been surprisingly successful for the interpretation of experimental data, especially at high forces, the WLC model lacks structural and dynamical molecular details associated with protein relaxation unde...

  6. Structure characteristics of electrical treeing in XLPE insulation under high frequencies

    Science.gov (United States)

    Bao, Minghui; Yin, Xiaogen; He, Junjia

    2011-07-01

    Electrical tree structure is one of the most important influencing factors for electrical treeing characteristics in polymers. In this paper, we focused on the structure characteristics of electrical treeing in cross-linked polyethylene (XLPE) insulation under high-frequency voltages. The tree structure characteristics include structure distribution characteristics and structure conversion characteristics. The influences of voltage, frequency, and pin-plane spacing on tree structure characteristics were analyzed based on the experimental results. It can be concluded that tree structures regularly change with the local electric field and frequency. The electric field in a very small zone near the needle tip is an important influencing factor for the formation of bush-like trees, and the lowest frequencies for the observed pure-vine-like trees increased with voltage. For double-structure trees, the local electric field at the transition location of the two structures remained almost unchanged with voltage and pin-plane spacing, but obviously increased with frequency. In order to investigate the relations of the growth rate and fractal dimension with tree structure characteristics, a new parameter, the energy threshold Wt, has been introduced and calculated for different tree structures.

  7. Negative Mood and Obsessive-Compulsive Related Clinical Constructs: An Examination of Underlying Factors

    Directory of Open Access Journals (Sweden)

    Gary I. Britton

    2017-09-01

    Full Text Available Emerging evidence suggests that many of the clinical constructs used to help understand and explain obsessive-compulsive (OC symptoms, and negative mood, may be causally interrelated. One approach to understanding this interrelatedness is a motivational systems approach. This approach suggests that rather than considering clinical constructs and negative affect as separable entities, they are all features of an integrated threat management system, and as such are highly coordinated and interdependent. The aim of the present study was to examine if clinical constructs related to OC symptoms and negative mood are best treated as separable or, alternatively, if these clinical constructs and negative mood are best seen as indicators of an underlying superordinate variable, as would be predicted by a motivational systems approach. A sample of 370 student participants completed measures of mood and the clinical constructs of inflated responsibility, intolerance of uncertainty, not just right experiences, and checking stop rules. An exploratory factor analysis suggested two plausible factor structures, one where all construct items and negative mood items loaded onto one underlying superordinate variable, and a second structure comprising of five factors, where each item loaded onto a factor representative of what the item was originally intended to measure. A confirmatory factor analysis showed that the five factor model was preferential to the one factor model, suggesting the four constructs and negative mood are best conceptualized as separate variables. Given the predictions of a motivational systems approach were not supported in the current study, other possible explanations for the causal interrelatedness between clinical constructs and negative mood are discussed.

  8. Structural first failure times under non-Gaussian stochastic behavior

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An analytical moment-based method for calculating structural first failure times under non-Gaussian stochastic behavior is proposed. In the method, a power series that constants can be obtained from response moments (skewness, kurtosis, etc.) is used firstly to map a non-Gaussian structural response into a standard Gaussian process, then mean up-crossing rates, mean clump size and the initial passage probability of a critical barrier level by the original structural response are estimated, and finally, the formula for calculating first failure times is established on the assumption that corrected up-crossing rates are independent. An analysis of a nonlinear single-degree-of-freedom dynamical system excited by a Gaussian model of load not only demonstrates the usage of the proposed method but also shows the accuracy and efficiency of the proposed method by comparisons between the present method and other methods such as Monte Carlo simulation and the traditional Gaussian model.

  9. Structural and electronic properties of carbon nanotubes under hydrostatic pressures

    Institute of Scientific and Technical Information of China (English)

    Zhang Ying; Cao Jue-Xian; Yang Wei

    2008-01-01

    We studied the structural and electronic properties of carbon nanotubes under hydrostatic pressures based on molecular dynamics simulations and first principles band structure calculations.It is found that carbon nanotubes experience a hard-to-soft transition as external pressure increases.The bulk modulus of soft phase is two orders of magnitude smaller than that of hard phase.The band structure calculations show that band gap of (10,0) nanotube increases with the increase of pressure at low pressures. Above a critical pressure (5.70GPa),band gap of (10,0) nanotube drops rapidly and becomes zero at 6.62GPa. Moreover,the calculated charge density shows that a large pressure can induce an sp2-to-sp3 bonding transition,which is confirmed by recent experiments on deformed carbon nanotubes.

  10. NAC transcription factors: structurally distinct, functionally diverse

    DEFF Research Database (Denmark)

    Olsen, Addie Nina; Ernst, Heidi A; Leggio, Leila Lo;

    2005-01-01

    NAC proteins constitute one of the largest families of plant-specific transcription factors, and the family is present in a wide range of land plants. Here, we summarize the biological and molecular functions of the NAC family, paying particular attention to the intricate regulation of NAC protei...

  11. A Study of Quasicrystal Structure Factors by Using Quantitative CBED

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The procedure of simulating convergent beam electron diffraction (CBED) pattern of quasicrystals by dynamical theory is described. The simulated patterns are generally coincide with the experimental patterns. The variations of intensity distribution in CBED pattern with the amplitude and phase of the structure factor of quasicrystai are caiculated with dynamical theory. The sensitivity of intensity distribution to the structure factor is investigated.

  12. Crystalline structures of poly(L-lactide) formed under pressure and structure transitions with heating

    DEFF Research Database (Denmark)

    Huang, Shaoyong; Li, Hongfei; Yu, Donghong;

    2013-01-01

    The isothermally crystallized poly(L-lactide) (PLLA) samples were obtained at 135 °C under pressures (Pc) ranging from 1 bar to 2.5 kbar. The crystalline structures, the structure transition, and thermal properties of the prepared samples were investigated by wide-angle X-ray diffraction (WAXD...... on the peculiarities of crystalline structure and crystallization behaviors, low and high pressure regions were revealed: disordered α crystal was formed in the high pressure region (>1 kbar). A layer located intermediate between crystalline and melt-like regions was observed, which finally took on crystalline order....... Reformation, disorder to order transformation, and recrystallization during heating completely changed the previous crystalline and stacking structure, a more stable crystalline structure was newly formed. The melting behaviors of samples indicate the crystalline and stacking structure formed under high...

  13. Crystalline structures of poly(L-lactide) formed under pressure and structure transitions with heating

    DEFF Research Database (Denmark)

    Huang, Shaoyong; Li, Hongfei; Yu, Donghong

    2013-01-01

    . Reformation, disorder to order transformation, and recrystallization during heating completely changed the previous crystalline and stacking structure, a more stable crystalline structure was newly formed. The melting behaviors of samples indicate the crystalline and stacking structure formed under high......The isothermally crystallized poly(L-lactide) (PLLA) samples were obtained at 135 °C under pressures (Pc) ranging from 1 bar to 2.5 kbar. The crystalline structures, the structure transition, and thermal properties of the prepared samples were investigated by wide-angle X-ray diffraction (WAXD......), real time synchrotron small-angle X-ray scattering (SR-SAXS) and differential scanning calorimetry (DSC) during this process. The structural parameters, such as the size of crystallites, the inverse spacing, the long periods and lamellae thicknesses decrease with pressure increasing. Based...

  14. Structural Genomics of Bacterial Virulence Factors

    Science.gov (United States)

    2006-05-01

    structure of pXO1-118 shown in its 2fo-fc electron density map. Arginine 74 and the two visible conformations of Phenylalanine 19 are shown. B...the methane monooxygenase hydroxylase from Methylococcus capsulatus (Bath): implications for substrate gating and component interac- tions. Proteins

  15. Factors influencing protein tyrosine nitration--structure-based predictive models.

    Science.gov (United States)

    Bayden, Alexander S; Yakovlev, Vasily A; Graves, Paul R; Mikkelsen, Ross B; Kellogg, Glen E

    2011-03-15

    Models for exploring tyrosine nitration in proteins have been created based on 3D structural features of 20 proteins for which high-resolution X-ray crystallographic or NMR data are available and for which nitration of 35 total tyrosines has been experimentally proven under oxidative stress. Factors suggested in previous work to enhance nitration were examined with quantitative structural descriptors. The role of neighboring acidic and basic residues is complex: for the majority of tyrosines that are nitrated the distance to the heteroatom of the closest charged side chain corresponds to the distance needed for suspected nitrating species to form hydrogen bond bridges between the tyrosine and that charged amino acid. This suggests that such bridges play a very important role in tyrosine nitration. Nitration is generally hindered for tyrosines that are buried and for those tyrosines for which there is insufficient space for the nitro group. For in vitro nitration, closed environments with nearby heteroatoms or unsaturated centers that can stabilize radicals are somewhat favored. Four quantitative structure-based models, depending on the conditions of nitration, have been developed for predicting site-specific tyrosine nitration. The best model, relevant for both in vitro and in vivo cases, predicts 30 of 35 tyrosine nitrations (positive predictive value) and has a sensitivity of 60/71 (11 false positives). Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Demographic Correlates and Factor Structure of the Family Environment Scale.

    Science.gov (United States)

    Boake, Corwin; Salmon, Paul G.

    1983-01-01

    Factor analyzed the Family Environment Scale (FES) subscale scores of 204 families and correlated them with family demographic characteristics. The obtained factor structure showed two major factors similar to "control" and "acceptance-rejection" dimensions in previous research. Results support the FES as part of multimethod…

  17. Factor Structure of the TOEFL Internet-Based Test

    Science.gov (United States)

    Sawaki, Yasuyo; Stricker, Lawrence J.; Oranje, Andreas H.

    2009-01-01

    This construct validation study investigated the factor structure of the Test of English as a Foreign Language[TM] Internet-based test (TOEFL[R] iBT). An item-level confirmatory factor analysis was conducted for a test form completed by participants in a field study. A higher-order factor model was identified, with a higher-order general factor…

  18. Path-integral and Ornstein-Zernike computations of quantum fluid structures under strong fluctuations

    Directory of Open Access Journals (Sweden)

    Luis M. Sesé

    2017-02-01

    Full Text Available This work deals with the computation of the structure factors of quantum fluids under complex conditions involving substantial density fluctuations and/or large particle delocalization effects. The method is based on the combination of path-integral Monte Carlo (PIMC simulations and the pair Ornstein-Zernike framework (OZ2. PIMC provides the radial correlation functions (centroid, instantaneous, and thermalized-continuous total linear response, which are used as data input to the OZ2 calculations that lead to their associated structure factors. To undertake this project normal liquid 4He and supercritical 3He are selected, studying conditions in the range (T = 4.2 K; 0.01886 <ρN/Å-3 < 0.02687. Full inter-comparison between the structure factors determined via both OZ2 and direct PIMC calculations is made. In addition, comparison with experimental data, including thermodynamic properties, is made wherever possible. The results establish that, even under severe thermodynamic and/or quantum fluctuation conditions, OZ2 remains in the quantum domain as a highly reliable and cost-effective framework to determine accurate structure factors, also allowing one to understand the related isotopic shifts in fluid He.

  19. Unascertained Factor Method of Dynamic Characteristic Analysis for Antenna Structures

    Institute of Scientific and Technical Information of China (English)

    ZHU Zeng-qing; LIANG Zhen-tao; CHEN Jian-jun

    2008-01-01

    The dynamic characteristic analysis model of antenna structures is built, in which the structural physical parameters and geometrical dimensions are all considered as unascertained variables, And a structure dynamic characteristic analysis method based on the unascertained factor method is given. The computational expression of structural characteristic is developed by the mathematics expression of unascertained factor and the principles of unascertained rational numbers arithmetic. An example is given, in which the possible values and confidence degrees of the unascertained structure characteristics are obtained. The calculated results show that the method is feasible and effective.

  20. Dynamic Trade Policy Game under Imperfect Factor Mobility

    OpenAIRE

    Kwan-Ho Kim

    2003-01-01

    This paper considers a dynamic strategic trade policy game when the sectoral movement of production factors is sluggish. A differential game between a domestic and foreign government is presented. The result of this dynamic game singles out two factors to determine the relative positions of the domestic firm and foreign firm at the steady state.

  1. Community structure benefits the fixation of cooperation under strong selection

    CERN Document Server

    Wu, Zhi-Xi; Yang, Han-Xin

    2014-01-01

    Recent empirical studies suggest that heavy-tailed distributions of human activities are universal in real social dynamics [Muchnik, \\emph{et al.}, Sci. Rep. \\textbf{3}, 1783 (2013)]. On the other hand, community structure is ubiquitous in biological and social networks [M.~E.~J. Newman, Nat. Phys. \\textbf{8}, 25 (2012)]. Motivated by these facts, we here consider the evolutionary Prisoner's dilemma game taking place on top of a real social network to investigate how the community structure and the heterogeneity in activity of individuals affect the evolution of cooperation. In particular, we account for a variation of the birth-death process (which can also be regarded as a proportional imitation rule from social point of view) for the strategy updating under both weak- and strong-selection (meaning the payoffs harvested from games contribute either slightly or heavily to the individuals' performance). By implementing comparative studies, where the players are selected either randomly or in terms of their ac...

  2. CARIBBEAN OFFSHORE CORPORATE STRUCTURES UNDER A SWOT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Ana-Maria GEAMÃNU

    2015-04-01

    Full Text Available Tax havens have long been under the attention of numerous Governments and International Organizations which triggered the concern of an uneven playing field in the taxation area. As a result numerous amendments have been made to both their commercial and tax legislations in order to be in line with the internationally agreed tax standards. The aim of this article is to conduct a SWOT analysis on the offshore corporate structures found in the Caribbean landscape. Based on a selection process of the most commonly recognized tax havens in the Caribbean region and an analysis of their offshore companies at the level of incorporation, administration, activities conducted and costs, a set of frequently met characteristics have been identified which stand at the basis of the SWOT analysis. The results stand to present a comprehensive four dimension framework of the offshore corporate structures in regards to their strengths, weaknesses, opportunities and threats.

  3. Airborne Transducer Integrity under Operational Environment for Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Mohammad Saleh Salmanpour

    2016-12-01

    Full Text Available This paper investigates the robustness of permanently mounted transducers used in airborne structural health monitoring systems, when exposed to the operational environment. Typical airliners operate in a range of conditions, hence, structural health monitoring (SHM transducer robustness and integrity must be demonstrated for these environments. A set of extreme temperature, altitude and vibration environment test profiles are developed using the existing Radio Technical Commission for Aeronautics (RTCA/DO-160 test methods. Commercially available transducers and manufactured versions bonded to carbon fibre reinforced polymer (CFRP composite materials are tested. It was found that the DuraAct transducer is robust to environmental conditions tested, while the other transducer types degrade under the same conditions.

  4. CARIBBEAN OFFSHORE CORPORATE STRUCTURES UNDER A SWOT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Ana-Maria GEAMÃNU

    2015-04-01

    Full Text Available Tax havens have long been under the attention of numerous Governments and International Organizations which triggered the concern of an uneven playing field in the taxation area. As a result numerous amendments have been made to both their commercial and tax legislations in order to be in line with the internationally agreed tax standards. The aim of this article is to conduct a SWOT analysis on the offshore corporate structures found in the Caribbean landscape. Based on a selection process of the most commonly recognized tax havens in the Caribbean region and an analysis of their offshore companies at the level of incorporation, administration, activities conducted and costs, a set of frequently met characteristics have been identified which stand at the basis of the SWOT analysis. The results stand to present a comprehensive four dimension framework of the offshore corporate structures in regards to their strengths, weaknesses, opportunities and threats.

  5. Capital Structure Arbitrage under a Risk-Neutral Calibration

    Directory of Open Access Journals (Sweden)

    Peter J. Zeitsch

    2017-01-01

    Full Text Available By reinterpreting the calibration of structural models, a reassessment of the importance of the input variables is undertaken. The analysis shows that volatility is the key parameter to any calibration exercise, by several orders of magnitude. To maximize the sensitivity to volatility, a simple formulation of Merton’s model is proposed that employs deep out-of-the-money option implied volatilities. The methodology also eliminates the use of historic data to specify the default barrier, thereby leading to a full risk-neutral calibration. Subsequently, a new technique for identifying and hedging capital structure arbitrage opportunities is illustrated. The approach seeks to hedge the volatility risk, or vega, as opposed to the exposure from the underlying equity itself, or delta. The results question the efficacy of the common arbitrage strategy of only executing the delta hedge.

  6. Electronic band structure of calcium selenide under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Louail, L. [Faculty of Sciences, Department of Physics, University of Setif, Setif (Algeria)], E-mail: llouail@yahoo.fr; Haddadi, K.; Maouche, D.; Ali Sahraoui, F.; Hachemi, A. [Faculty of Sciences, Department of Physics, University of Setif, Setif (Algeria)

    2008-09-01

    Energy band structures under pressure of calcium selenide (CaSe) were calculated using the plane-wave pseudopotential code CASTEP. The results show a progressive transition from a direct to an indirect gap semiconductor at a pressure of about 2 GPa, in the B1 phase. An insulator-conductor change was also observed at 70 GPa, in the B2 phase. Concerning CaSe, these two results could not be evidenced in previous literature. Hence, our work is a first attempt in this direction.

  7. Structural characterization of lipidic systems under nonequilibrium conditions

    DEFF Research Database (Denmark)

    Yaghmur, Anan; Rappolt, Michael

    2012-01-01

    manipulation techniques including, for instance, stop-flow mixing or rapid temperature-jump perturbation is given. Second, our recent synchrotron SAXS findings on the dynamic structural response of gold nanoparticle-loaded vesicles upon exposure to an ultraviolet light source, the impact of rapidly mixing...... and the possible formation of intermediate states in the millisecond to second range. The need for investigating self-assembled systems, mainly stimuli-responsive drug nanocarriers, under nonequilibrium conditions is discussed. For pharmaceutically relevant applications, it is essential to combine...

  8. Topological spin-singlet superconductors with underlying sublattice structure

    Science.gov (United States)

    Dutreix, C.

    2017-07-01

    Majorana boundary quasiparticles may naturally emerge in a spin-singlet superconductor with Rashba spin-orbit interactions when a Zeeman magnetic field breaks time-reversal symmetry. Their existence and robustness against adiabatic changes is deeply related, via a bulk-edge correspondence, to topological properties of the band structure. The present paper shows that the spin-orbit may be responsible for topological transitions when the superconducting system has an underlying sublattice structure, as it appears in a dimerized Peierls chain, graphene, and phosphorene. These systems, which belong to the Bogoliubov-de Gennes class D, are found to have an extra symmetry that plays the role of the parity. It enables the characterization of the topology of the particle-hole symmetric band structure in terms of band inversions. The topological phase diagrams this leads to are then obtained analytically and exactly. They reveal that, because of the underlying sublattice structure, the existence of topological superconducting phases requires a minimum doping fixed by the strength of the Rashba spin orbit. Majorana boundary quasiparticles are finally predicted to emerge when the Fermi level lies in the vicinity of the bottom (top) of the conduction (valence) band in semiconductors such as the dimerized Peierls chain and phosphorene. In a two-dimensional topological superconductor based on (stretched) graphene, which is semimetallic, Majorana quasiparticles cannot emerge at zero and low doping, that is, when the Fermi level is close to the Dirac points. Nevertheless, they are likely to appear in the vicinity of the van Hove singularities.

  9. On structural design optimization under uncertainty and risk

    Science.gov (United States)

    Teófilo Beck, André; José de Santana Gomes, Wellison

    2010-06-01

    In this paper, the effects of uncertainty and risk on structural design optimization are investigated, by comparing results of Deterministic Design Optimization (DDO), Reliability-based Design Optimization (RBDO) and Reliability-based Risk Optimization (RBRO). DDO yields a structural topology (or shape) which is optimum in terms of mechanics, but does not explicitly address parameter uncertainties and their effects on structural safety. RBDO properly models safety-under-uncertainty, allowing the optimum structure to maintain an acceptable level of safety. Results, however, are dependent on the failure probability used as constraint. Risk optimization (RBRO) increases the scope of the problem, by addressing the compromising goals of economy and safety. This is accomplished by quantifying the costs associated to construction, operation and maintenance, as well as the monetary consequences of failure. RBRO yields the optimum topology and the optimum point of balance between economy and safety. Results are compared for some example problems. The broader RBRO solution is found first, and optimum results are used as constraints in DDO and RBDO. Results show that even when the optimum safety coefficients are used as constraint in DDO, the formulation leads to optimum configurations which respect these design constraints, reduce manufacturing costs but increase total expected costs (including expected cost of failure). If the (optimum) system failure probability is used as constraint in RBDO, the optimum solution reduces manufacturing costs, but by increasing total expected costs. This happens when the costs associated to different failure modes are distinct.

  10. Active stabilization of thin-wall structures under compressive loading

    Science.gov (United States)

    Welham, Jared; Calius, Emilio P.; Chase, J. Geoffrey

    2003-08-01

    The active suppression of elastic buckling instability has the potential to significantly increase the effective strength of thin-wall structures. Despite all the interest in smart structures, the active suppression of buckling has received comparatively little attention. This paper addresses the effects of embedded actuation on the compression buckling strength of laminated composite plates through analysis and simulation. Numerical models are formulated that include the influence of essential features such as sensor uncertainty and noise, actuator saturation and control architecture on the buckling process. Silicon-based strain sensors and diffuse laser distance sensors are both considered for use in the detection of incipient buckling behavior due to their increased sensitivity. Actuation is provided by paired distributions of piezo-electric material incorporated into both sides of the laminate. Optimal controllers are designed to command the structure to deform in ways that interfere with the development of buckling mode shapes. Commercial software packages are used to solve the resulting non-linear equations, and some of the tradeoffs are enumerated. Overall, the results show that active buckling control can considerably enhance resistance to instability under compressive loads. These buckling load predictions demonstrate the viability of optimal control and piezo-electric actuation for implementing active buckling control. Due to the importance of early detection, the relative effectiveness of active buckling control is shown to be strongly dependent on the performance of the sensing scheme, as well as on the characteristics of the structure.

  11. Structural analysis of red blood cell aggregates under shear flow.

    Science.gov (United States)

    Chesnutt, J K W; Marshall, J S

    2010-03-01

    A set of measures of red blood cell (RBC) aggregates are developed and applied to examine the aggregate structure under plane shear and channel flows. Some of these measures are based on averages over the set of red blood cells which are in contact with each other at a given time. Other measures are developed by first fitting an ellipse to the planar projection of the aggregate, and then examining the area and aspect ratio of the fit ellipse as well as the orientations of constituent RBCs with respect to the fit ellipse axes. The aggregate structural measures are illustrated using a new mesoscale computational model for blood cell transport, collision and adhesion. The sensitivity of this model to change in adhesive surface energy density and shear rate on the aggregate structure is examined. It is found that the mesoscale model predictions exhibit reasonable agreement with experimental and theoretical data for blood flow in plane shear and channel flows. The new structural measures are used to examine the differences between predictions of two- and three-dimensional computations of the aggregate formation, showing that two-dimensional computations retain some of the important aspects of three-dimensional computations.

  12. Two cross-linguistic factors underlying tongue shapes for vowels

    Energy Technology Data Exchange (ETDEWEB)

    Nix, D.A.; Papcun, G.; Hogden, J.; Zlokarnik, I. [Los Alamos National Lab., NM (United States)

    1996-06-01

    Desirable characteristics of a vocal-tract parametrization include accuracy, low dimensionality, and generalizability across speakers and languages. A low-dimensional, speaker-independent linear parametrization of vowel tongue shapes can be obtained using the PARAFAC three-mode factor analysis procedure. Harshman et al. applied PARAFAC to midsagittal x-ray vowel data from five English speakers, reporting that two speaker-independent factors are required to accurately represent the tongue shape measured along anatomically normalized vocal-tract diameter grid lines. Subsequently, the cross-linguistic generality of this parametrization was brought into question by the application of PARAFAC to Icelandic vowel data, where three nonorthogonal factors were reported. This solution is shown to be degenerate; a reanalysis of Jackson`s Icelandic data produces two factors that match Harshman et al.`s factors for English vowels, contradicting Jackson`s distinction between English and Icelandic language-specific `articulatory primes.` To obtain vowel factors not constrained by artificial measurement grid lines, x-ray tongue shape traces of six English speakers were marked with 13 equally spaced points. PARAFAC analysis of this unconstranied (x,y) coordinate data results in two factors that are clearly interpretable in terms of the traditional vowel quality dimensions front/back, high/low. 14 refs., 8 figs., 2 tabs.

  13. Looking under the Bonnet: Factors Affecting Student Adoption of E-Learning Systems in Jordan

    Directory of Open Access Journals (Sweden)

    Muneer Mahmood Abbad, David Morris, Carmel de Nahlik

    2009-04-01

    Full Text Available The primary questions addressed in this paper are the following: what are the factors that affect students’ adoption of an e-learning system and what are the relationships among these factors?This paper investigates and identifies some of the major factors affecting students’ adoption of an e-learning system in a university in Jordan. E-learning adoption is approached from the information systems acceptance point of view. This suggests that a prior condition for learning effectively using e-learning systems is that students must actually use them. Thus, a greater knowledge of the factors that affect IT adoption and their interrelationships is a pre-cursor to a better understanding of student acceptance of e-learning systems. In turn, this will help and guide those who develop, implement, and deliver e-learning systems.In this study, an extended version of the Technology Acceptance Model (TAM was developed to investigate the underlying factors that influence students’ decisions to use an e-learning system. The TAM was populated using data gathered from a survey of 486 undergraduate students using the Moodle based e-learning system at the Arab Open University. The model was estimated using Structural Equation Modelling (SEM. A path model was developed to analyze the relationships between the factors to explain students’ adoption of the e-learning system. Whilst findings support existing literature about prior experience affecting perceptions, they also point to surprising group effects, which may merit future exploration.

  14. Cooperation under Incomplete Information on the Discount Factors

    CERN Document Server

    Maor, C

    2010-01-01

    In the repeated Prisoner's Dilemma, when every player has a different discount factor, the grim-trigger strategy is an equilibrium if and only if the discount factor of each player is higher than some threshold. What happens if the players have incomplete information regarding the discount factors? In this work we look at repeated games in which each player has incomplete information regarding the other player's discount factor, and ask when a pair of grim-trigger strategies is an equilibrium. We provide necessary and sufficient conditions for such strategies to be an equilibrium. We characterize the states of the world in which the strategies are not triggered, i.e., the players cooperate, in such equilibria (or $\\epsilon$-equilibria), and ask whether these "cooperation events" are close to those in the complete information case, when the information is "almost" complete, in several senses.

  15. [Dynamic changes of soil ecological factors in Ziwuling secondary forest area under human disturbance].

    Science.gov (United States)

    Zhou, Zhengchao; Shangguan, Zhouping

    2005-09-01

    As a widespread natural phenomenon, disturbance is considered as a discrete event occurred in natural ecosystems at various spatial and temporal scales. The occurrence of disturbance directly affects the structure, function and dynamics of ecosystems. Forest logging and forestland assart, the common human disturbances in forest area, have caused the dynamic changes of forest soil ecological factors in a relatively consistent environment. A study on the dynamics of soil bulk density, soil organic matter, soil microbes and other soil ecological factors under different human disturbance (logging and assart, logging but without assart, control) were conducted in the Ziwuling secondary forest area. The results indicated that human disturbance had a deep impact on the soil ecological factors, with soil physical and chemical properties become bad, soil organic matter decreased from 2.2% to 0.8%, and soil stable aggregates dropped more than 30%. The quantity of soil microbes decreased sharply with enhanced human disturbance. Soil organic matter and soil microbes decreased more than 50% and 90%, respectively, and soil bulk density increased from 0.9 to 1.21 g x cm(-3) with increasing soil depth. Ditch edge level also affected the dynamics of soil factors under the same disturbance, with a better soil ecological condition at low-than at high ditch edge level.

  16. Structure and bonding in crystalline cesium uranyl tetrachloride under pressure.

    Science.gov (United States)

    Osman, Hussien H; Pertierra, Pilar; Salvadó, Miguel A; Izquierdo-Ruiz, F; Recio, J M

    2016-07-21

    A thorough investigation of pressure effects on the structural properties of crystalline cesium uranyl chloride was performed by means of first-principles calculations within the density functional theory framework. Total energies, equilibrium geometries and vibrational frequencies were computed at selected pressures up to 50 GPa. Zero pressure results present good agreement with available experimental and theoretical data. Our calculated equation of state parameters reveal that Cs2UO2Cl4 is a high compressible material, similar to other ionic compounds with cesium cations, and displays a structural anisotropic behavior guided by the uranyl moiety. An unexpected variation of the U-O bond length, dUO, is detected as pressure is applied. It leads to a dUO-stretching frequency relationship that cannot be described by the traditional Badger's rule. Interestingly enough, it can be explained in terms of a change in the main factor controlling dUO. At low pressure, the charge transferred to the uranyl cation induces an increase of the bond length and a red shift of the stretching frequencies, whereas it is the mechanical effect of the applied pressure above 10 GPa that is the dominant factor that leads to a shortening of dUO and a blue shift of the stretching frequencies.

  17. Structure evolution of HoMnO3 under pressure

    Science.gov (United States)

    Liu, Z.; Dera, P. K.; Yang, W.; Liu, H.

    2012-12-01

    Hexagonal manganites belong to a special group called ferroelectromagnets, in which frustrated antiferromagnetic and ferroelectric orders coexist. These materials attract much attention for the potential applications on transducers, magnetic field sensors, as well as the information storage industry. Hexagonal manganites can be converted to orthorhombic structure at 1000 °C, 4 GPa conditions. The transition can also be realized under high pressure at room temperature, as observed in TmMnO3, YMnO3, LuMnO3, etc. The structure stability of hexagonal manganites is therefore of both fundamental and applied interests. In this paper, X-ray diffraction was performed on HoMnO3 single crystal under pressure up to 43 GPa by using helium as pressure medium. At 35.6 GPa, HoMnO3 converts to another hexagonal phase, whose lattice parameter along c axis reduces to half. The P-V data can be well fitted by 3-order Birch-Murnaghan equation with K0 = 154 GPa and K0' = 4.6.

  18. Structural Health Monitoring under Nonlinear Environmental or Operational Influences

    Directory of Open Access Journals (Sweden)

    Jyrki Kullaa

    2014-01-01

    Full Text Available Vibration-based structural health monitoring is based on detecting changes in the dynamic characteristics of the structure. It is well known that environmental or operational variations can also have an influence on the vibration properties. If these effects are not taken into account, they can result in false indications of damage. If the environmental or operational variations cause nonlinear effects, they can be compensated using a Gaussian mixture model (GMM without the measurement of the underlying variables. The number of Gaussian components can also be estimated. For the local linear components, minimum mean square error (MMSE estimation is applied to eliminate the environmental or operational influences. Damage is detected from the residuals after applying principal component analysis (PCA. Control charts are used for novelty detection. The proposed approach is validated using simulated data and the identified lowest natural frequencies of the Z24 Bridge under temperature variation. Nonlinear models are most effective if the data dimensionality is low. On the other hand, linear models often outperform nonlinear models for high-dimensional data.

  19. Fine structure behaviour of VVER-1000 RPV materials under irradiation

    Science.gov (United States)

    Gurovich, B. A.; Kuleshova, E. A.; Shtrombakh, Ya. I.; Erak, D. Yu.; Chernobaeva, A. A.; Zabusov, O. O.

    2009-06-01

    Changes in the fine structure and mechanical properties of the base metal (BM) and weld metal (WM) of VVER-1000 pressure vessels during accumulation of neutron dose in the range of fluences ˜(3.2-15) × 10 23 m -2 ( E > 0.5 MeV) at 290 °C are studied using methods of transmission electron microscopy, fractographic analysis, and Auger electron spectroscopy. A correlation was found between the changes of mechanical properties and the micro- and nano-structures of the studied steels. Accumulation of neutron dose considerably raises the strength characteristics and transition temperature of VVER-1000 pressure vessel steels. The rate of changes in the mechanical properties of the weld metal is significantly higher than that of the base metal. The slower growth of strength characteristics and transition temperature shift of the base metal under irradiation as compared with the weld metal is due to the slower growth of the density of radiation defects and radiation-induced precipitates. The level of intergranular embrittlement under irradiation in the weld metal is not higher then in the base metal in spite of the higher content of nickel.

  20. Revisiting the Leadership Scale for Sport: Examining Factor Structure Through Exploratory Structural Equation Modeling.

    Science.gov (United States)

    Chiu, Weisheng; Rodriguez, Fernando M; Won, Doyeon

    2016-10-01

    This study examines the factor structure of the shortened version of the Leadership Scale for Sport, through a survey of 201 collegiate swimmers at National Collegiate Athletic Association Division II and III institutions, using both exploratory structural equation modeling and confirmatory factor analysis. Both exploratory structural equation modeling and confirmatory factor analysis showed that a five-factor solution fit the data adequately. The sizes of factor loadings on target factors substantially differed between the confirmatory factor analysis and exploratory structural equation modeling solutions. In addition, the inter-correlations between factors of the Leadership Scale for Sport and the correlations with athletes' satisfaction were found to be inflated in the confirmatory factor analysis solution. Overall, the findings provide evidence of the factorial validity of the shortened Leadership Scale for Sport.

  1. Lesion Mapping the Four-Factor Structure of Emotional Intelligence

    Directory of Open Access Journals (Sweden)

    Joachim Thomas Operskalski

    2015-12-01

    Full Text Available Emotional intelligence refers to an individual’s ability to process and respond to emotions, including recognizing the expression of emotions in others, using emotions to enhance thought and decision making, and regulating emotions to drive effective behaviors. Despite their importance for goal-directed social behavior, little is known about the neural mechanisms underlying specific facets of emotional intelligence. Here, we report findings from a study investigating the neural bases of these specific components for emotional intelligence in a sample of 130 combat veterans with penetrating traumatic brain injury. We examined the neural mechanisms underlying experiential (perceiving and using emotional information and strategic (understanding and managing emotions facets of emotional intelligence. Factor scores were submitted to voxel-based lesion symptom mapping to elucidate their neural substrates. The results indicate that two facets of emotional intelligence (perceiving and managing emotions engage common and distinctive neural systems, with shared dependence on the social knowledge network, and selective engagement of the orbitofrontal and parietal cortex for strategic aspects of emotional information processing. The observed pattern of findings suggests that sub-facets of experiential and strategic emotional intelligence can be characterized as separable but related processes that depend upon a core network of brain structures within frontal, temporal and parietal cortex.

  2. Lesion Mapping the Four-Factor Structure of Emotional Intelligence

    Science.gov (United States)

    Operskalski, Joachim T.; Paul, Erick J.; Colom, Roberto; Barbey, Aron K.; Grafman, Jordan

    2015-01-01

    Emotional intelligence (EI) refers to an individual’s ability to process and respond to emotions, including recognizing the expression of emotions in others, using emotions to enhance thought and decision making, and regulating emotions to drive effective behaviors. Despite their importance for goal-directed social behavior, little is known about the neural mechanisms underlying specific facets of EI. Here, we report findings from a study investigating the neural bases of these specific components for EI in a sample of 130 combat veterans with penetrating traumatic brain injury. We examined the neural mechanisms underlying experiential (perceiving and using emotional information) and strategic (understanding and managing emotions) facets of EI. Factor scores were submitted to voxel-based lesion symptom mapping to elucidate their neural substrates. The results indicate that two facets of EI (perceiving and managing emotions) engage common and distinctive neural systems, with shared dependence on the social knowledge network, and selective engagement of the orbitofrontal and parietal cortex for strategic aspects of emotional information processing. The observed pattern of findings suggests that sub-facets of experiential and strategic EI can be characterized as separable but related processes that depend upon a core network of brain structures within frontal, temporal and parietal cortex. PMID:26858627

  3. Lesion Mapping the Four-Factor Structure of Emotional Intelligence.

    Science.gov (United States)

    Operskalski, Joachim T; Paul, Erick J; Colom, Roberto; Barbey, Aron K; Grafman, Jordan

    2015-01-01

    Emotional intelligence (EI) refers to an individual's ability to process and respond to emotions, including recognizing the expression of emotions in others, using emotions to enhance thought and decision making, and regulating emotions to drive effective behaviors. Despite their importance for goal-directed social behavior, little is known about the neural mechanisms underlying specific facets of EI. Here, we report findings from a study investigating the neural bases of these specific components for EI in a sample of 130 combat veterans with penetrating traumatic brain injury. We examined the neural mechanisms underlying experiential (perceiving and using emotional information) and strategic (understanding and managing emotions) facets of EI. Factor scores were submitted to voxel-based lesion symptom mapping to elucidate their neural substrates. The results indicate that two facets of EI (perceiving and managing emotions) engage common and distinctive neural systems, with shared dependence on the social knowledge network, and selective engagement of the orbitofrontal and parietal cortex for strategic aspects of emotional information processing. The observed pattern of findings suggests that sub-facets of experiential and strategic EI can be characterized as separable but related processes that depend upon a core network of brain structures within frontal, temporal and parietal cortex.

  4. Elasticity, structure, and relaxation of extended proteins under force

    Science.gov (United States)

    Stirnemann, Guillaume; Giganti, David; Fernandez, Julio M.; Berne, B. J.

    2013-01-01

    Force spectroscopies have emerged as a powerful and unprecedented tool to study and manipulate biomolecules directly at a molecular level. Usually, protein and DNA behavior under force is described within the framework of the worm-like chain (WLC) model for polymer elasticity. Although it has been surprisingly successful for the interpretation of experimental data, especially at high forces, the WLC model lacks structural and dynamical molecular details associated with protein relaxation under force that are key to the understanding of how force affects protein flexibility and reactivity. We use molecular dynamics simulations of ubiquitin to provide a deeper understanding of protein relaxation under force. We find that the WLC model successfully describes the simulations of ubiquitin, especially at higher forces, and we show how protein flexibility and persistence length, probed in the force regime of the experiments, are related to how specific classes of backbone dihedral angles respond to applied force. Although the WLC model is an average, backbone model, we show how the protein side chains affect the persistence length. Finally, we find that the diffusion coefficient of the protein’s end-to-end distance is on the order of 108 nm2/s, is position and side-chain dependent, but is independent of the length and independent of the applied force, in contrast with other descriptions. PMID:23407163

  5. Auction-based resource allocation game under a hierarchical structure

    Science.gov (United States)

    Cui, Yingying; Zou, Suli; Ma, Zhongjing

    2016-01-01

    This paper studies a class of auction-based resource allocation games under a hierarchical structure, such that each supplier is assigned a certain amount of resource from a single provider and allocates it to its buyers with auction mechanisms. To implement the efficient allocations for the underlying hierarchical system, we first design an auction mechanism, for each local system composed of a supplier and its buyers, which inherits the advantages of the progressive second price mechanism. By employing a dynamic algorithm, each local system converges to its own efficient Nash equilibrium, at which the efficient resource allocation is achieved and the bidding prices of all the buyers in this local system are identical with each other. After the local systems reach their own equilibria respectively, the resources assigned to suppliers are readjusted via a dynamic hierarchical algorithm with respect to the bidding prices associated with the implemented equilibria of local systems. By applying the proposed hierarchical process, the formulated hierarchical system can converge to the efficient allocation under certain mild conditions. The developed results in this work are demonstrated with simulations.

  6. Size-dependent structure of silver nanoparticles under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Koski, Kristie Jo [Univ. of California, Berkeley, CA (United States)

    2008-12-31

    Silver noble metal nanoparticles that are<10 nm often possess multiply twinned grains allowing them to adopt shapes and atomic structures not observed in bulk materials. The properties exhibited by particles with multiply twinned polycrystalline structures are often far different from those of single-crystalline particles and from the bulk. I will present experimental evidence that silver nanoparticles<10 nm undergo a reversible structural transformation under hydrostatic pressures up to 10 GPa. Results for nanoparticles in the intermediate size range of 5 to 10 nm suggest a reversible linear pressure-dependent rhombohedral distortion which has not been previously observed in bulk silver. I propose a mechanism for this transitiion that considers the bond-length distribution in idealized multiply twinned icosahedral particles. Results for nanoparticles of 3.9 nm suggest a reversible linear pressure-dependent orthorhombic distortion. This distortion is interpreted in the context of idealized decahedral particles. In addition, given these size-dependent measurements of silver nanoparticle compression with pressure, we have constructed a pressure calibration curve. Encapsulating these silver nanoparticles in hollow metal oxide nanospheres then allows us to measure the pressure inside a nanoshell using x-ray diffraction. We demonstrate the measurement of pressure gradients across nanoshells and show that these nanoshells have maximum resolved shear strengths on the order of 500 MPa to IGPa.

  7. Structure of a financial cross-correlation matrix under attack

    Science.gov (United States)

    Lim, Gyuchang; Kim, SooYong; Kim, Junghwan; Kim, Pyungsoo; Kang, Yoonjong; Park, Sanghoon; Park, Inho; Park, Sang-Bum; Kim, Kyungsik

    2009-09-01

    We investigate the structure of a perturbed stock market in terms of correlation matrices. For the purpose of perturbing a stock market, two distinct methods are used, namely local and global perturbation. The former involves replacing a correlation coefficient of the cross-correlation matrix with one calculated from two Gaussian-distributed time series while the latter reconstructs the cross-correlation matrix just after replacing the original return series with Gaussian-distributed time series. Concerning the local case, it is a technical study only and there is no attempt to model reality. The term ‘global’ means the overall effect of the replacement on other untouched returns. Through statistical analyses such as random matrix theory (RMT), network theory, and the correlation coefficient distributions, we show that the global structure of a stock market is vulnerable to perturbation. However, apart from in the analysis of inverse participation ratios (IPRs), the vulnerability becomes dull under a small-scale perturbation. This means that these analysis tools are inappropriate for monitoring the whole stock market due to the low sensitivity of a stock market to a small-scale perturbation. In contrast, when going down to the structure of business sectors, we confirm that correlation-based business sectors are regrouped in terms of IPRs. This result gives a clue about monitoring the effect of hidden intentions, which are revealed via portfolios taken mostly by large investors.

  8. Adjoint Techniques for Topology Optimization of Structures Under Damage Conditions

    Science.gov (United States)

    Akgun, Mehmet A.; Haftka, Raphael T.

    2000-01-01

    The objective of this cooperative agreement was to seek computationally efficient ways to optimize aerospace structures subject to damage tolerance criteria. Optimization was to involve sizing as well as topology optimization. The work was done in collaboration with Steve Scotti, Chauncey Wu and Joanne Walsh at the NASA Langley Research Center. Computation of constraint sensitivity is normally the most time-consuming step of an optimization procedure. The cooperative work first focused on this issue and implemented the adjoint method of sensitivity computation (Haftka and Gurdal, 1992) in an optimization code (runstream) written in Engineering Analysis Language (EAL). The method was implemented both for bar and plate elements including buckling sensitivity for the latter. Lumping of constraints was investigated as a means to reduce the computational cost. Adjoint sensitivity computation was developed and implemented for lumped stress and buckling constraints. Cost of the direct method and the adjoint method was compared for various structures with and without lumping. The results were reported in two papers (Akgun et al., 1998a and 1999). It is desirable to optimize topology of an aerospace structure subject to a large number of damage scenarios so that a damage tolerant structure is obtained. Including damage scenarios in the design procedure is critical in order to avoid large mass penalties at later stages (Haftka et al., 1983). A common method for topology optimization is that of compliance minimization (Bendsoe, 1995) which has not been used for damage tolerant design. In the present work, topology optimization is treated as a conventional problem aiming to minimize the weight subject to stress constraints. Multiple damage configurations (scenarios) are considered. Each configuration has its own structural stiffness matrix and, normally, requires factoring of the matrix and solution of the system of equations. Damage that is expected to be tolerated is local

  9. Activity of recombinant factor VIIa under different conditions in vitro

    DEFF Research Database (Denmark)

    Bladbjerg, Else-Marie; Jespersen, Jørgen

    2008-01-01

    , but no effects on clotting time indicating that haemodilution does not affect clot formation, but the clot formed at high haemodilution may not be so firm. In conclusion, the activity of recombinant activated factor VII was affected in vitro by pH, temperature, and haemodilution. Additional studies are necessary...... investigated the in-vitro effects of pH, temperature, and haemodilution on the activity of recombinant activated factor VII. Samples from eight healthy volunteers were spiked with recombinant activated factor VII (final concentration 1.7 microg/ml) and adjusted to pH 6.0, 6.5, 7.0, and 7.4 or analysed at 30...... activity in plasma. Significant effects of pH were observed for clotting time, clot formation time, maximum clot firmness, and factor VII coagulant activity in the direction of longer clot formation times and less firm clots with decreasing pH. Temperature had significant effects on clotting time, clot...

  10. Factors Underlying the Public's Credibility Perceptions in Educational Evaluations

    Science.gov (United States)

    Jacobson, Miriam R.

    2016-01-01

    Understanding how evaluation audiences perceive credibility can help evaluators design evaluations and reports that support appropriate use. While researchers have studied credibility assessment among various educational stakeholders, little research has been conducted with the broader public. This study explored potential factors affecting the…

  11. Factors Underlying the Public's Credibility Perceptions in Educational Evaluations

    Science.gov (United States)

    Jacobson, Miriam R.

    2016-01-01

    Understanding how evaluation audiences perceive credibility can help evaluators design evaluations and reports that support appropriate use. While researchers have studied credibility assessment among various educational stakeholders, little research has been conducted with the broader public. This study explored potential factors affecting the…

  12. Risk Factors for Mortality of Pediatric Patients Without Underlying Diseases

    Directory of Open Access Journals (Sweden)

    Ling-Sai Chang

    2011-02-01

    Conclusion: Results from this study suggest that mortality in pediatric patients without underlying diseases is most frequently found in younger children with CNS and cardiovascular infections, consciousness change, and high liver enzyme levels at admission. Results from this analysis will provide information for the awareness of fatal outcomes in previously healthy children.

  13. 'Mum never loved me.' How structural factors influence adolescent ...

    African Journals Online (AJOL)

    How structural factors influence adolescent sexual and reproductive health ... Research in high income countries shows parent–child connectedness to be ... to young people's low self-esteem and risky sexual behaviour while unplanned ...

  14. Maximum Likelihood Factor Structure of the Family Environment Scale.

    Science.gov (United States)

    Fowler, Patrick C.

    1981-01-01

    Presents the maximum likelihood factor structure of the Family Environment Scale. The first bipolar dimension, "cohesion v conflict," measures relationship-centered concerns, while the second unipolar dimension is an index of "organizational and control" activities. (Author)

  15. Matrix factorization method for the Hamiltonian structure of integrable systems

    Indian Academy of Sciences (India)

    S Ghosh; B Talukdar; S Chakraborti

    2003-07-01

    We demonstrate that the process of matrix factorization provides a systematic mathematical method to investigate the Hamiltonian structure of non-linear evolution equations characterized by hereditary operators with Nijenhuis property.

  16. Assessment of Available Transfer Capability (ATC Using Linear Sensitivity Factors under Deregulated Environment

    Directory of Open Access Journals (Sweden)

    K. Indhumathy

    2013-06-01

    Full Text Available Electric supply industry throughout the world have been restructured to introduce competition among the market participants and bring several competitive opportunities. The structure of power industry is moving towards deregulatory environment from the regulatory environment. Under this deregulatory, there are many technical issues need to be addressed. In this paper, one such technical issue handled carefully is the Available Transfer Capability (ATC. ATC is the amount of maximum additional power transfer between two control areas (source and sink that is available without violating thermal overloads. Here ATC is estimated for normal and contingency modes using linear sensitivity factors according to the security and reliability requirements. Simultaneous bilateral transactions havebeen done on IEEE-30 bus standard system for the assessment of ATC under MATLAB environment. From the results, it is computed that ATC is determined with less computation burden and this study willbe useful for the present open access electricity market.

  17. Bacterial Sigma Factors and Anti-Sigma Factors: Structure, Function and Distribution

    OpenAIRE

    Paget, Mark S.

    2015-01-01

    Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play critical roles in transcription initiation, including the recognition and opening of promoters as well as the initial steps in RNA synthesis. This review focuses on the structure and function of the major sigma-70 class that includes the housekeeping sigma factor (Group 1) that directs the bulk of transcription during active growth, and structurally-related alternative sigma factors (Groups 2–4) that control ...

  18. Structure factor determination of amorphous materials by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Cuello, Gabriel J [Institut Laue Langevin, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble Cedex 9 (France)], E-mail: cuello@ill.eu

    2008-06-18

    An introduction is given to structure factor determination by means of neutron diffraction. The method of isotopic substitution, which allows us to separate the partial correlation functions, is also presented. Suitable instruments, the experimental procedures, and corrections are described. Other less-conventional techniques such as isomorphic substitution and anomalous dispersion are also discussed. Finally, examples of the structure factor determination in chalcogenide, molecular, telluride and phosphate glasses are discussed in order to illustrate the usefulness of the neutron diffraction technique.

  19. Brain mineralocorticoid receptors as resilience factor under adverse life conditions?

    NARCIS (Netherlands)

    Kanatsou, S.

    2016-01-01

    Studies in human cohorts have underlined the importance of gene-environment interactions for brain structure and function during development and in adulthood. Such interactions can make the difference between staying healthy or succumbing to disease, e.g. depression or posttraumatic stress disorder.

  20. Brain mineralocorticoid receptors as resilience factor under adverse life conditions?

    NARCIS (Netherlands)

    Kanatsou, S.

    2016-01-01

    Studies in human cohorts have underlined the importance of gene-environment interactions for brain structure and function during development and in adulthood. Such interactions can make the difference between staying healthy or succumbing to disease, e.g. depression or posttraumatic stress disorder.

  1. Structure and regulatory function of plant transcription factors

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The expression of inducible genes in plants is regulated byspecific transcription factors at the transcriptional level. A typical transcription factor usually contains a DNA-binding domain, a transcription regulation domain, a dimerization site and a nuclear localization domain. These functional domains define the characteristic, localization and regulatory role of a transcription factor. Transcription factors recognize and bind to specific cis-acting elements or interact with other proteins, and then activate or repress the transcription of target genes by their functional domains. In recent years, elucidation on the structure and function of transcription factors has become an important subject in plant molecular biology.

  2. Self-Structuring of Granular material under Capillary Bulldozing

    Science.gov (United States)

    Dumazer, Guillaume; Sandnes, Bjørnar; Ayaz, Monem; Måløy, Knut Jørgen; Flekkøy, Eirik

    2017-06-01

    An experimental observation of the structuring of a granular suspension under the progress of a gas/liquid meniscus in a narrow tube is reported here. The granular material is moved and compactifies as a growing accumulation front. The frictional interaction with the confining walls increases until the pore capillary entry pressure is reached. The gas then penetrates the clogged granular packing and a further accumulation front is formed at the far side of the plug. This cyclic process continues until the gas/liquid interface reaches the tube's outlet, leaving a trail of plugs in the tube. Such 1D pattern formation belongs to a larger family of patterning dynamics observed in 2D Hele-Shaw geometry. The cylindrical geometry considered here provides an ideal case for a theoretical modelling for forced granular matter oscillating between a long frictional phase and a sudden viscous fluidization.

  3. Directed networks with underlying time structures from multivariate time series

    CERN Document Server

    Tanizawa, Toshihiro; Taya, Fumihiko

    2014-01-01

    In this paper we propose a method of constructing directed networks of time-dependent phenomena from multivariate time series. As the construction method is based on the linear model, the network fully reflects dynamical features of the system such as time structures of periodicities. Furthermore, this method can construct networks even if these time series show no similarity: situations in which common methods fail. We explicitly introduce a case where common methods do not work. This fact indicates the importance of constructing networks based on dynamical perspective, when we consider time-dependent phenomena. We apply the method to multichannel electroencephalography~(EEG) data and the result reveals underlying interdependency among the components in the brain system.

  4. Correction factors for assessing immersion suits under harsh conditions.

    Science.gov (United States)

    Power, Jonathan; Tikuisis, Peter; Ré, António Simões; Barwood, Martin; Tipton, Michael

    2016-03-01

    Many immersion suit standards require testing of thermal protective properties in calm, circulating water while these suits are typically used in harsher environments where they often underperform. Yet it can be expensive and logistically challenging to test immersion suits in realistic conditions. The goal of this work was to develop a set of correction factors that would allow suits to be tested in calm water yet ensure they will offer sufficient protection in harsher conditions. Two immersion studies, one dry and the other with 500 mL of water within the suit, were conducted in wind and waves to measure the change in suit insulation. In both studies, wind and waves resulted in a significantly lower immersed insulation value compared to calm water. The minimum required thermal insulation for maintaining heat balance can be calculated for a given mean skin temperature, metabolic heat production, and water temperature. Combining the physiological limits of sustainable cold water immersion and actual suit insulation, correction factors can be deduced for harsh conditions compared to calm. The minimum in-situ suit insulation to maintain thermal balance is 1.553-0.0624·TW + 0.00018·TW(2) for a dry calm condition. Multiplicative correction factors to the above equation are 1.37, 1.25, and 1.72 for wind + waves, 500 mL suit wetness, and both combined, respectively. Calm water certification tests of suit insulation should meet or exceed the minimum in-situ requirements to maintain thermal balance, and correction factors should be applied for a more realistic determination of minimum insulation for harsh conditions. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  5. Personality Factors Underlying Suicidal Behavior Among Military Youth

    OpenAIRE

    Soltaninejad, Abdollah; Fathi-Ashtiani, Ali; Ahmadi, Khodabakhsh; Mirsharafoddini, Hediye Sadat; Nikmorad, Alireza; Pilevarzadeh, Motahare

    2014-01-01

    Background: Suicidal behavior is one the most significant mental health problems in the military. Militaries are closed systems that operate in particular situations. Military service is associated with certain stressful conditions. On this basis, there is likely of trauma in the military environment. Measures of suicidal behavior are pathologically complex. A range of biological, psychological, social, and institutional factors are involved in the incidence and prevalence of these behaviors....

  6. Personality Factors Underlying Suicidal Behavior Among Military Youth

    OpenAIRE

    Soltaninejad, Abdollah; Fathi-Ashtiani, Ali; Ahmadi, Khodabakhsh; Mirsharafoddini, Hediye Sadat; Nikmorad, Alireza; Pilevarzadeh, Motahare

    2014-01-01

    Background: Suicidal behavior is one the most significant mental health problems in the military. Militaries are closed systems that operate in particular situations. Military service is associated with certain stressful conditions. On this basis, there is likely of trauma in the military environment. Measures of suicidal behavior are pathologically complex. A range of biological, psychological, social, and institutional factors are involved in the incidence and prevalence of these behaviors....

  7. RISK FACTORS FOR PANCREATIC CANCER: UNDERLYING MECHANISMS AND POTENTIAL TARGETS

    Directory of Open Access Journals (Sweden)

    Thomas eKolodecik

    2014-01-01

    Full Text Available Purpose of the review:Pancreatic cancer is extremely aggressive, forming highly chemo-resistant tumors, and has one of the worst prognoses. The evolution of this cancer is multi-factorial. Repeated acute pancreatic injury and inflammation are important contributing factors in the development of pancreatic cancer. This article attempts to understand the common pathways linking pancreatitis to pancreatic cancer.Recent Findings:Intracellular activation of both pancreatic enzymes and the transcription factor NF-kB are important mechanisms that induce acute pancreatitis. Recurrent pancreatic injury due to genetic susceptibility, environmental factors such as smoking, alcohol intake, and conditions such as obesity lead to increases in oxidative stress, impaired autophagy and constitutive activation of inflammatory pathways. These processes can stimulate pancreatic stellate cells, thereby increasing fibrosis and encouraging chronic disease development. Activation of oncogneic Kras mutations through inflammation, coupled with altered levels of tumor suppressor proteins (p53 and p16 can ultimately lead to development of pancreatic cancer. Summary:Although our understanding of pancreatitis and pancreatic cancer has tremendously increased over many years, much remains to be elucidated in terms of common pathways linking these conditions.

  8. Risk factors for pancreatic cancer: underlying mechanisms and potential targets

    Science.gov (United States)

    Kolodecik, Thomas; Shugrue, Christine; Ashat, Munish; Thrower, Edwin C.

    2014-01-01

    Purpose of the review: Pancreatic cancer is extremely aggressive, forming highly chemo-resistant tumors, and has one of the worst prognoses. The evolution of this cancer is multi-factorial. Repeated acute pancreatic injury and inflammation are important contributing factors in the development of pancreatic cancer. This article attempts to understand the common pathways linking pancreatitis to pancreatic cancer. Recent findings: Intracellular activation of both pancreatic enzymes and the transcription factor NF-κB are important mechanisms that induce acute pancreatitis (AP). Recurrent pancreatic injury due to genetic susceptibility, environmental factors such as smoking, alcohol intake, and conditions such as obesity lead to increases in oxidative stress, impaired autophagy and constitutive activation of inflammatory pathways. These processes can stimulate pancreatic stellate cells, thereby increasing fibrosis and encouraging chronic disease development. Activation of oncogenic Kras mutations through inflammation, coupled with altered levels of tumor suppressor proteins (p53 and p16) can ultimately lead to development of pancreatic cancer. Summary: Although our understanding of pancreatitis and pancreatic cancer has tremendously increased over many years, much remains to be elucidated in terms of common pathways linking these conditions. PMID:24474939

  9. Factor Structure of Japanese Versions of Two Emotional Intelligence Scales

    Science.gov (United States)

    Fukuda, Eriko; Saklofske, Donald H.; Tamaoka, Katsuo; Fung, Tak Shing; Miyaoka, Yayoi; Kiyama, Sachiko

    2011-01-01

    This article reports the psychometric properties of two emotional intelligence measures translated into Japanese. Confirmatory factor analysis (CFA) was conducted to examine the factor structure of a Japanese version of the Wong and Law Emotional Intelligence Scale (WLEIS) completed by 310 Japanese university students. A second study employed CFA…

  10. Experimental Study For Pizometric Head Distribution Under Hydraulic Structures

    Directory of Open Access Journals (Sweden)

    Dr. Najm Obaid Salim Alghazali

    2015-04-01

    Full Text Available Abstract In this research the experimental method by using Hydraulic modeling used to determination the flow net in order to analyses seepage flow through single- layer soil foundation underneath hydraulic structure. as well as steady the consequence of the cut-off inclination angle on exit gradient factor of safety uplift pressure and quantity of seepage by using seepage tank were designed in the laboratory with proper dimensions with two cutoffs . The physical model seepage tank was designed in two downstream cutoff angles which are 90 and 120 and upstream cutoff angles 90 45 120. After steady state flow the flow line is constructed by dye injection in the soil from the upstream side in front view of the seepage tank and the equipotentials line can be constructed by pizometer fixed to measure the total head. From the result It is concluded that using downstream cut-off inclined towards the downstream side with amp1256 equal 120 that given value of redaction 25 is beneficial in increasing the safety factor against the piping phenomenon. using upstream cut-off inclined towards the downstream side with amp1256 equal 45 that given value of redaction 52 is beneficial in decreasing uplift pressure and quantity of seepage.

  11. On the compression of aluminium foam structures under shock

    Science.gov (United States)

    Townsend, D.; Parry, S.; Bourne, N. K.; Withers, P. J.; Wood, D. C.; Appleby-Thomas, G. J.; Hameed, A.

    2017-01-01

    Foam-based materials have an important role as both blast and impact mitigators, with their extended sub-surface structures providing multiple redundant routes for load management and distribution in the event of failure. In order to further elucidate underlying stress management mechanisms at high strain-rates, here, open cell and closed cell Aluminium were investigated via the plate-impact technique. These experiments allowed the material to be loaded under a macroscale one-dimensional state of strain. The nature of pore collapse was monitored via manganin stress gauges at the target rear surface, with resultant data related back to changes in microstructure via microstructural analysis of both un-impacted and recovered target material. Results indicated crushing of the open cell foam occurred without retarding the flyer plate and the observed shock pressures suggested the degree of compaction increased with impact velocity. The higher density closed cell foam caused significant deceleration of the flyer plate during passage through the specimen and significantly lower shock pressures were observed at the anvil compared to the open cell material.

  12. Structural evolution of zirconium carbide under ion irradiation

    Science.gov (United States)

    Gosset, D.; Dollé, M.; Simeone, D.; Baldinozzi, G.; Thomé, L.

    2008-02-01

    Zirconium carbide is one of the candidate materials to be used for some fuel components of the high temperature nuclear reactors planned in the frame of the Gen-IV project. Few data exist regarding its behaviour under irradiation. We have irradiated ZrC samples at room temperature with slow heavy ions (4 MeV Au, fluence from 10 11 to 5 × 10 15 cm -2) in order to simulate neutron irradiations. Grazing incidence X-Ray diffraction (GIXRD) and transmission electron microscopy (TEM) analysis have been performed in order to study the microstructural evolution of the material versus ion fluence. A high sensitivity to oxidation is observed with the formation of zirconia precipitates during the ion irradiations. Three damage stages are observed. At low fluence (high micro-strains appear together with small faulted dislocation loops. At the highest fluence (>10 14 cm -2), the micro-strains saturate and the loops coalesce to form a dense dislocation network. No other structural modification is observed. The material shows a moderate cell parameter increase, corresponding to a 0.6 vol.% swelling, which saturates around 10 14 ions/cm 2, i.e., a few Zr dpa. As a result, in spite of a strong covalent bonding component, ZrC seems to have a behaviour under irradiation close to cubic metals.

  13. Composite failure prediction of π-joint structures under bending

    Institute of Scientific and Technical Information of China (English)

    HUANG Hong-me; YUAN Shen-fang

    2012-01-01

    In this article,the composite π-joint is investigated under bending loads.The "L" preform is the critical component regarding composite π-joint failure.The study is presented in the failure detection of a carbon fiber composite π-joint structure under bending loads using fiber Bragg grating (FBG) sensor.Firstly,based on the general finite element method (FEM)software,the 3-D finite element (FE) model of composite π-joint is established,and the failure process and every lamina failure load of composite π-joint are investigated by maximum stress criteria.Then,strain distributions along the length of FBG are extracted,and the reflection spectra of FBG are calculated according to the strain distribution.Finally,to verify the numerical results,a test scheme is performed and the experimental spectra of FBG are recorded.The experimental results indicate that the failure sequence and the corresponding critical loads of failure are consistent with the numerical predictions,and the computational error of failure load is less than 6.4%.Furthermore,it also verifies the feasibility of the damage detection system.

  14. Exploring the factor structure of the Food Cravings Questionnaire-Trait in Cuban adults.

    Science.gov (United States)

    Rodríguez-Martín, Boris C; Molerio-Pérez, Osana

    2014-01-01

    Food cravings refer to an intense desire to eat specific foods. The Food Cravings Questionnaire-Trait (FCQ-T) is the most commonly used instrument to assess food cravings as a multidimensional construct. Its 39 items have an underlying nine-factor structure for both the original English and Spanish version; but subsequent studies yielded fewer factors. As a result, a 15-item version of the FCQ-T with one-factor structure has been proposed (FCQ-T-reduced; see this Research Topic). The current study aimed to explore the factor structure of the Spanish version for both the FCQ-T and FCQ-T-reduced in a sample of 1241 Cuban adults. Results showed a four-factor structure for the FCQ-T, which explained 55% of the variance. Factors were highly correlated. Using the items of the FCQ-T-reduced only showed a one-factor structure, which explained 52% of the variance. Both versions of the FCQ-T were positively correlated with body mass index (BMI), scores on the Food Thoughts Suppression Inventory and weight cycling. In addition, women had higher scores than men and restrained eaters had higher scores than unrestrained eaters. To summarize, results showed that (1) the FCQ-T factor structure was significantly reduced in Cuban adults and (2) the FCQ-T-reduced may represent a good alternative to efficiently assess food craving on a trait level.

  15. Exploring the factor structure of the Food Cravings Questionnaire-Trait in Cuban adults

    Directory of Open Access Journals (Sweden)

    Boris C. Rodríguez-Martín

    2014-03-01

    Full Text Available Food cravings refer to an intense desire to eat specific foods. The Food Cravings Questionnaire-Trait (FCQ-T is the most commonly used instrument to assess food cravings as a multidimensional construct. Its 39 items have an underlying nine-factor structure for both the original English and Spanish version; but subsequent studies yielded fewer factors. As a result, a 15-item version of the FCQ-T with one-factor structure has been proposed (FCQ-T-reduced; see this Research Topic. The current study aimed to explore the factor structure of the Spanish version for both the FCQ-T and FCQ-T-reduced in a sample of 1241 Cuban adults. Results showed a four-factor structure for the FCQ-T, which explained 55 % of the variance. Factors were highly correlated. Using the items of the FCQ-T-reduced only showed a one-factor structure, which explained 52% of the variance. Both versions of the FCQ-T were positively correlated with body mass index, scores on the Food Thoughts Suppression Inventory and weight cycling. In addition, women had higher scores than men and restrained eaters had higher scores than unrestrained eaters. To summarize, results showed that 1 the FCQ-T factor structure was significantly reduced in Cuban adults and 2 the FCQ-T-reduced may represent a good alternative to efficiently assess food craving on a trait level.

  16. Target and structural materials under dual-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Camus, E.; Wanderka, N.; Wollenberger, H. [Hahn-Meitner-Institut Berlin GmbH (Germany)

    1995-11-01

    The European Spallation Source (ESS) is planned to have a beam power of 5 MW (3.75 mA of 1.334 GeV protons). This is by a factor 30 higher than the available most powerful spallation source ISIS at Rutherford-Appleton Lab. (RAL) in Great-Britain. This causes a damage rate of approx. 10 dpa (displacements per atom) per month in target materials (W or Ta) or structural materials. The problem of radiation damage by high energy protons in different alloys has been recently reviewed. At HMI, simulation irradiation using heavy ions and helium or hydrogen ions at the dual-beam facility are being out. Here, we report on some preliminary results obtained on tantalum as target material and on ferritic/martensitic steels (HT9 type steels or comparable steels), which are proposed to be used as structural materials. Goal of these investigations is to correlate the results with those obtained at spallation irradiated specimens and to investigate the unexplored field of simultaneous production of damage, helium and hydrogen at high levels. (author) 4 figs., 1 tab., 9 refs.

  17. Analysis of Dynamic Properties of Piezoelectric Structure under Impact Load

    Directory of Open Access Journals (Sweden)

    Taotao Zhang

    2015-10-01

    Full Text Available An analytical model of the dynamic properties is established for a piezoelectric structure under impact load, without considering noise and perturbations in this paper. Based on the general theory of piezo-elasticity and impact mechanics, the theoretical solutions of the mechanical and electrical fields of the smart structure are obtained with the standing and traveling wave methods, respectively. The comparisons between the two methods have shown that the standing wave method is better for studying long-time response after an impact load. In addition, good agreements are found between the theoretical and the numerical results. To simulate the impact load, both triangle and step pulse loads are used and comparisons are given. Furthermore, the influence of several parameters is discussed so as to provide some advices for practical use. It can be seen that the proposed analytical model would benefit, to some extent, the design and application (especially the airport runway of the related smart devices by taking into account their impact load performance.

  18. Exploring the factor structure of the Food Cravings Questionnaire-Trait in Cuban adults

    OpenAIRE

    Rodríguez-Martín, Boris C.; Molerio-Pérez, Osana

    2014-01-01

    Food cravings refer to an intense desire to eat specific foods. The Food Cravings Questionnaire-Trait (FCQ-T) is the most commonly used instrument to assess food cravings as a multidimensional construct. Its 39 items have an underlying nine-factor structure for both the original English and Spanish version; but subsequent studies yielded fewer factors. As a result, a 15-item version of the FCQ-T with one-factor structure has been proposed (FCQ-T-reduced; see this Research Topic). The current ...

  19. Influence of environmental factors on corrosion damage of aircraft structure

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Corrosion is one of the important structural integrity concerns of aging aircraft, and it is estimated that a significant portion of airframe maintenance budgets is directed towards corrosion-related problems for both military and commercial aircraft. In order to better understand how environmental factors influence the corrosion damage initiation and propagation on aircraft structure and to predict pre-corrosion test pieces of fatigue life and structural integrity of an effective approach, this paper uses ...

  20. Factor structure of functional state of primary school age children

    Directory of Open Access Journals (Sweden)

    Davidenko O.V.

    2011-02-01

    Full Text Available The examination of primary school children to determine the ranking of significant factors that determine the structure of their functional state depending on the level of physical health. It is shown that the main factor in the structure of the functional state of younger schoolchildren in low-and lower-middle level of physical fitness is selected morpho-functional status, which characterizes the functions of the body at rest. For children with average or above average level of physical fitness is a leading factor in physical fitness of schoolchildren.

  1. Biology, Genetics, and Environment: Underlying Factors Influencing Alcohol Metabolism.

    Science.gov (United States)

    Wall, Tamara L; Luczak, Susan E; Hiller-Sturmhöfel, Susanne

    2016-01-01

    Gene variants encoding several of the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), are among the largest genetic associations with risk for alcohol dependence. Certain genetic variants (i.e., alleles)--particularly the ADH1B*2, ADH1B*3, ADH1C*1, and ALDH2*2 alleles--have been associated with lower rates of alcohol dependence. These alleles may lead to an accumulation of acetaldehyde during alcohol metabolism, which can result in heightened subjective and objective effects. The prevalence of these alleles differs among ethnic groups; ADH1B*2 is found frequently in northeast Asians and occasionally Caucasians, ADH1B*3 is found predominantly in people of African ancestry, ADH1C*1 varies substantially across populations, and ALDH2*2 is found almost exclusively in northeast Asians. Differences in the prevalence of these alleles may account at least in part for ethnic differences in alcohol consumption and alcohol use disorder (AUD). However, these alleles do not act in isolation to influence the risk of AUD. For example, the gene effects of ALDH2*2 and ADH1B*2 seem to interact. Moreover, other factors have been found to influence the extent to which these alleles affect a person's alcohol involvement, including developmental stage, individual characteristics (e.g., ethnicity, antisocial behavior, and behavioral undercontrol), and environmental factors (e.g., culture, religion, family environment, and childhood adversity).

  2. Molecular and structural advances in tissue factor-dependent coagulation.

    Science.gov (United States)

    Kirchhofer, D; Banner, D W

    1997-11-01

    The tissue factor:factor VIIa (TF-F.VIIa) complex is considered the physiological initiator of blood coagulation. Besides its role in normal hemostasis, this enzyme complex has been found to play an important role in various thrombotic disorders and thus has become an attractive target for the development of new anticoagulants. Recently, significant progress has been made in regard to structural and molecular aspects of TF-VIIa-initiated coagulation. A rather complete picture on how tissue factor binds to factor VIIa has emerged and is discussed in detail in this review. Also, the combined data of the TF-F.VIIa crystal structure, of naturally occurring F.VII variants, and of mutagenesis studies provide a framework to discuss molecular aspects of the tissue factor-mediated enhancement of F.VIIa catalytic efficiency and the recognition of macromolecular substrates. F.VIIa as a member of the serine protease family has an active site homologous to other coagulation factors. The release of the coordinates of the crystal structures of F.X and F.IX, together with the earlier determined thrombin structure, now allows a detailed comparison of these active centers with respect to the development of specific and potent active site inhibitors. This structural and molecular information about the TF-F.VIIa complex and other coagulation enzymes adds to our understanding of blood coagulation and should further the development of new classes of anticoagulants. (Trends Cardiovasc Med 1997;7:316-324). © 1997, Elsevier Science Inc.

  3. Factor Structure in Commodity Futures Return and Volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Lunde, Asger; Olesen, Kasper Vinther

    Using data on more than 750 million futures trades during 2004-2013, we analyze eight stylized facts of commodity price and volatility dynamics in the post financialization period. We pay particular attention to the factor structure in returns and volatility and to commodity market integration...... with the equity market. We find evidence of a factor structure in daily commodity futures returns. However, the factor structure in daily commodity futures volatility is even stronger than in returns. When computing model-free realized commodity betas with the stock market we find that they were high during 2008......-2010 but have since returned to the pre-crisis level close to zero. The common factor in commodity volatility is nevertheless clearly related to stock market volatility. We conclude that, while commodity markets appear to again be segmented from the equity market when only returns are considered, commodity...

  4. The asymptotic convergence factor for a polygon under a perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Li, X. [Georgia Southern Univ., Statesboro, GA (United States)

    1994-12-31

    Let Ax = b be a large system of linear equations, where A {element_of} C{sup NxN}, nonsingular and b {element_of} C{sup N}. A few iterative methods for solving have recently been presented in the case where A is nonsymmetric. Many of their algorithms consist of two phases: Phase I: estimate the extreme eigenvalues of A; Phase II: construct and apply an iterative method based on the estimates. For convenience, it is rewritten as an equivalent fixed-point form, x = Tx + c. Let {Omega} be a compact set excluding 1 in the complex plane, and let its complement in the extended complex plane be simply connected. The asymptotic convergence factor (ACF) for {Omega}, denoted by {kappa}({Omega}), measures the rate of convergence for the asymptotically optimal semiiterative methods for solving, where {sigma}(T) {contained_in} {Omega}.

  5. Factors affecting survivability of local Rohilkhand goats under organized farm

    Directory of Open Access Journals (Sweden)

    D. Upadhyay

    2015-10-01

    Full Text Available Aim: To study the pattern of mortality as affected by age, season and various diseases in local goats of Rohilkhand region maintained at the Indian Veterinary Research Institute, Bareilly. Materials and Methods: Post-mortem records of 12 years (2000-01 to 2011-12 were used, and total 243 mortality data were collected and analyzed. The causes of mortality were classified into seven major classes viz. digestive disorders, respiratory disorders, cardiovascular disorders, musculoskeletal disorder, parasitic disorders, mixed disorders (combination of digestive, respiratory, parasitic, and cardiovascular disorders and miscellaneous disorders (cold, hypoglycemia, emaciation, endometritis, traumatic injury, etc.. Results: The average mortality was 10.93%. The overall mortality was more during rainy season followed by winter and summer season. The mortality in 4-6 months of age was high (2.52% followed by 0-1 month (2.34% and 2-3 months (1.35%. The average mortality among adult age groups (>12 months was 3.42%. The mortality showed declining trend with the advancement of age up to 3 months and then again increased in 4-6 months age group. The digestive diseases (3.51% followed by respiratory diseases (1.89% and parasitic diseases (1.48% contributed major share to the total mortality occurred and the remaining disorders were of lesser significance in causing death in goats. There is significant (p<0.01; χ2=55.62 association between year with season and age with the season (p<0.05, χ2=16.083 found in the present study. Conclusion: This study confirms that overall mortality rate averaged 10.93% (ranged between 1.10% and 25.56% over 12 years under semi-intensive farm condition. It was generally higher in rainy season. The mortality remains higher in kids particularly under 1 month of age. The digestive diseases contributed major share to overall mortality.

  6. The importance of building construction materials relative to other factors affecting structure survival during wildfire

    Science.gov (United States)

    Syphard, Alexandra D.; Brennan, Teresa J.; Keeley, Jon E.

    2017-01-01

    Structure loss to wildfire is a serious problem in wildland-urban interface areas across the world. Laboratory experiments suggest that fire-resistant building construction and design could be important for reducing structure destruction, but these need to be evaluated under real wildfire conditions, especially relative to other factors. Using empirical data from destroyed and surviving structures from large wildfires in southern California, we evaluated the relative importance of building construction and structure age compared to other local and landscape-scale variables associated with structure survival. The local-scale analysis showed that window preparation was especially important but, in general, creating defensible space adjacent to the home was as important as building construction. At the landscape scale, structure density and structure age were the two most important factors affecting structure survival, but there was a significant interaction between them. That is, young structure age was most important in higher-density areas where structure survival overall was more likely. On the other hand, newer-construction structures were less likely to survive wildfires at lower density. Here, appropriate defensible space near the structure and accessibility to major roads were important factors. In conclusion, community safety is a multivariate problem that will require a comprehensive solution involving land use planning, fire-safe construction, and property maintenance.

  7. A New Look at the Big Five Factor Structure through Exploratory Structural Equation Modeling

    Science.gov (United States)

    Marsh, Herbert W.; Ludtke, Oliver; Muthen, Bengt; Asparouhov, Tihomir; Morin, Alexandre J. S.; Trautwein, Ulrich; Nagengast, Benjamin

    2010-01-01

    NEO instruments are widely used to assess Big Five personality factors, but confirmatory factor analyses (CFAs) conducted at the item level do not support their a priori structure due, in part, to the overly restrictive CFA assumptions. We demonstrate that exploratory structural equation modeling (ESEM), an integration of CFA and exploratory…

  8. Comparative study of factor structure of Raven's Coloured Progressive Matrices.

    Science.gov (United States)

    Schmidtke, A; Schaller, S

    1980-12-01

    The Raven Coloured Progressive Matrices were administered on group or individual bases to children ranging in age from 4 yr. 9 mo. to 11 yr. 0 mo. (N = 728). Factor analysis yielded three factors: 1. Perceptual closure involving complex figures and patterns with heterogeneous inner structures, 2. Concrete and abstract reasoning, 3. Completion of homogeneous patterns and recognition of given elements. Factor matrix comparisons across age groups resulted in a mean similarity coefficient of .75. Comparisons of data with earlier analyses also resulted in high similarity. This supports the hypothesis of a three-factor structure rather than a four-factor solution or a simple dual classification into items which can be solved by perceptual processes and those which require conceptual solutions.

  9. Factors underlying restricted crossover localization in barley meiosis.

    Science.gov (United States)

    Higgins, James D; Osman, Kim; Jones, Gareth H; Franklin, F Chris H

    2014-01-01

    Meiotic recombination results in the formation of cytological structures known as chiasmata at the sites of genetic crossovers (COs). The formation of at least one chiasma/CO between homologous chromosome pairs is essential for accurate chromosome segregation at the first meiotic division as well as for generating genetic variation. Although DNA double-strand breaks, which initiate recombination, are widely distributed along the chromosomes, this is not necessarily reflected in the chiasma distribution. In many species there is a tendency for chiasmata to be distributed in favored regions along the chromosomes, whereas in others, such as barley and some other grasses, chiasma localization is extremely pronounced. Localization of chiasma to the distal regions of barley chromosomes restricts the genetic variation available to breeders. Studies reviewed herein are beginning to provide an explanation for chiasma localization in barley. Moreover, they suggest a potential route to manipulating chiasma distribution that could be of value to plant breeders.

  10. Bacterial Sigma Factors and Anti-Sigma Factors: Structure, Function and Distribution.

    Science.gov (United States)

    Paget, Mark S

    2015-06-26

    Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play critical roles in transcription initiation, including the recognition and opening of promoters as well as the initial steps in RNA synthesis. This review focuses on the structure and function of the major sigma-70 class that includes the housekeeping sigma factor (Group 1) that directs the bulk of transcription during active growth, and structurally-related alternative sigma factors (Groups 2-4) that control a wide variety of adaptive responses such as morphological development and the management of stress. A recurring theme in sigma factor control is their sequestration by anti-sigma factors that occlude their RNAP-binding determinants. Sigma factors are then released through a wide variety of mechanisms, often involving branched signal transduction pathways that allow the integration of distinct signals. Three major strategies for sigma release are discussed: regulated proteolysis, partner-switching, and direct sensing by the anti-sigma factor.

  11. Reliability prediction for structures under cyclic loads and recurring inspections

    Directory of Open Access Journals (Sweden)

    Alberto W. S. Mello Jr

    2009-06-01

    Full Text Available This work presents a methodology for determining the reliability of fracture control plans for structures subjected to cyclic loads. It considers the variability of the parameters involved in the problem, such as initial flaw and crack growth curve. The probability of detection (POD curve of the field non-destructive inspection method and the condition/environment are used as important factors for structural confidence. According to classical damage tolerance analysis (DTA, inspection intervals are based on detectable crack size and crack growth rate. However, all variables have uncertainties, which makes the final result totally stochastic. The material properties, flight loads, engineering tools and even the reliability of inspection methods are subject to uncertainties which can affect significantly the final maintenance schedule. The present methodology incorporates all the uncertainties in a simulation process, such as Monte Carlo, and establishes a relationship between the reliability of the overall maintenance program and the proposed inspection interval, forming a “cascade” chart. Due to the scatter, it also defines the confidence level of the “acceptable” risk. As an example, the damage tolerance analysis (DTA results are presented for the upper cockpit longeron splice bolt of the BAF upgraded F-5EM. In this case, two possibilities of inspection intervals were found: one that can be characterized as remote risk, with a probability of failure (integrity nonsuccess of 1 in 10 million, per flight hour; and other as extremely improbable, with a probability of nonsuccess of 1 in 1 billion, per flight hour, according to aviation standards. These two results are compared with the classical military airplane damage tolerance requirements.

  12. Unraveling the Molecular Mechanisms Underlying the Nasopharyngeal Bacterial Community Structure

    Directory of Open Access Journals (Sweden)

    Wouter A. A. de Steenhuijsen Piters

    2016-03-01

    Full Text Available The upper respiratory tract is colonized by a diverse array of commensal bacteria that harbor potential pathogens, such as Streptococcus pneumoniae. As long as the local microbial ecosystem—also called “microbiome”—is in balance, these potentially pathogenic bacterial residents cause no harm to the host. However, similar to macrobiological ecosystems, when the bacterial community structure gets perturbed, potential pathogens can overtake the niche and cause mild to severe infections. Recent studies using next-generation sequencing show that S. pneumoniae, as well as other potential pathogens, might be kept at bay by certain commensal bacteria, including Corynebacterium and Dolosigranulum spp. Bomar and colleagues are the first to explore a specific biological mechanism contributing to the antagonistic interaction between Corynebacterium accolens and S. pneumoniae in vitro [L. Bomar, S. D. Brugger, B. H. Yost, S. S. Davies, K. P. Lemon, mBio 7(1:e01725-15, 2016, doi:10.1128/mBio.01725-15]. The authors comprehensively show that C. accolens is capable of hydrolyzing host triacylglycerols into free fatty acids, which display antipneumococcal properties, suggesting that these bacteria might contribute to the containment of pneumococcus. This work exemplifies how molecular epidemiological findings can lay the foundation for mechanistic studies to elucidate the host-microbe and microbial interspecies interactions underlying the bacterial community structure. Next, translation of these results to an in vivo setting seems necessary to unveil the magnitude and importance of the observed effect in its natural, polymicrobial setting.

  13. Pricing Decision under Dual-Channel Structure considering Fairness and Free-Riding Behavior

    Directory of Open Access Journals (Sweden)

    Yongmei Liu

    2014-01-01

    Full Text Available Under dual-channel structure, the free-riding behavior based on different service levels between online channel and offline channel cannot be avoided, which would lead to channel unfairness. This study implies that the dual-channel supply chain is built up by online channel controlled by manufacturer and traditional channel controlled by retailer, respectively. Under this channel structure, we rebuild the linear demand function considering free-riding behavior and modify the pricing model based on channel fairness. Then the influences of fair factor and free-riding behavior on manufacturer and retailer pricing and performance are discussed. Finally, we propose some numerical analysis to provide some valuable recommendations for manufacturer and retailer improving channel management performance.

  14. Cognitive and Ocular Factors Jointly Determine Pupil Responses under Equiluminance.

    Directory of Open Access Journals (Sweden)

    Tomas Knapen

    Full Text Available Changes in pupil diameter can reflect high-level cognitive signals that depend on central neuromodulatory mechanisms. However, brain mechanisms that adjust pupil size are also exquisitely sensitive to changes in luminance and other events that would be considered a nuisance in cognitive experiments recording pupil size. We implemented a simple auditory experiment involving no changes in visual stimulation. Using finite impulse-response fitting we found pupil responses triggered by different types of events. Among these are pupil responses to auditory events and associated surprise: cognitive effects. However, these cognitive responses were overshadowed by pupil responses associated with blinks and eye movements, both inevitable nuisance factors that lead to changes in effective luminance. Of note, these latter pupil responses were not recording artifacts caused by blinks and eye movements, but endogenous pupil responses that occurred in the wake of these events. Furthermore, we identified slow (tonic changes in pupil size that differentially influenced faster (phasic pupil responses. Fitting all pupil responses using gamma functions, we provide accurate characterisations of cognitive and non-cognitive response shapes, and quantify each response's dependence on tonic pupil size. These results allow us to create a set of recommendations for pupil size analysis in cognitive neuroscience, which we have implemented in freely available software.

  15. Generating functions for Wilf equivalence under generalized factor order

    CERN Document Server

    Langley, Thomas; Remmel, Jeffrey

    2010-01-01

    Kitaev, Liese, Remmel, and Sagan recently defined generalized factor order on words comprised of letters from a partially ordered set $(P, \\leq_P)$ by setting $u \\leq_P w$ if there is a subword $v$ of $w$ of the same length as $u$ such that the $i$-th character of $v$ is greater than or equal to the $i$-th character of $u$ for all $i$. This subword $v$ is called an embedding of $u$ into $w$. For the case where $P$ is the positive integers with the usual ordering, they defined the weight of a word $w = w_1\\ldots w_n$ to be $\\text{wt}(w) = x^{\\sum_{i=1}^n w_i} t^{n}$, and the corresponding weight generating function $F(u;t,x) = \\sum_{w \\geq_P u} \\text{wt}(w)$. They then defined two words $u$ and $v$ to be Wilf equivalent, denoted $u \\backsim v$, if and only if $F(u;t,x) = F(v;t,x)$. They also defined the related generating function $S(u;t,x) = \\sum_{w \\in \\mathcal{S}(u)} \\text{wt}(w)$ where $\\mathcal{S}(u)$ is the set of all words $w$ such that the only embedding of $u$ into $w$ is a suffix of $w$, and showed t...

  16. Underlying causal factors associated with construction worker fatalities involving stepladders

    Directory of Open Access Journals (Sweden)

    Aneurin Thomas James Grant

    2013-03-01

    Full Text Available Stepladders are frequently utilized on construction projects as a means of access to elevation. Stepladder heights commonly range from 4 feet (1.2 m to 14 feet (4.3 m. Since these heights are not extreme, there is a common misperception that stepladder use presents a low risk. On the contrary, extreme care must be exercised to ensure that work on stepladders is performed safely, as described in the conspicuously located recommendations and brightly-colored warnings that adorn virtually all newly-purchased equipment. Despite this, accidents involving stepladders occur on a regular basis.  This study was conducted to better understand the underlying causes of these accidents. The narrative descriptions of 180 stepladder-related fatalities were obtained from the U.S. Occupational Safety and Health Administration and were analyzed to identify the at-risk behaviors that preceded the fatality incidents. The results showed that most of the incidents should have been anticipated and could have been avoided. Unsafe practices such as improper lockout-tagout of electrical equipment, loss of balance, working on a folded stepladder, over-reaching, straddling the ladder, “walking” the ladder, poor footing, and unstable/shifting ladders, among others were identified. Virtually all of these fatalities could have been avoided by adhering to the guidelines posted on the stepladders and by complying with basic safe construction practices.

  17. Underlying causal factors associated with construction worker fatalities involving stepladders

    Directory of Open Access Journals (Sweden)

    Aneurin Thomas James Grant

    2013-03-01

    Full Text Available Stepladders are frequently utilized on construction projects as a means of access to elevation. Stepladder heights commonly range from 4 feet (1.2 m to 14 feet (4.3 m. Since these heights are not extreme, there is a common misperception that stepladder use presents a low risk. On the contrary, extreme care must be exercised to ensure that work on stepladders is performed safely, as described in the conspicuously located recommendations and brightly-colored warnings that adorn virtually all newly-purchased equipment. Despite this, accidents involving stepladders occur on a regular basis.  This study was conducted to better understand the underlying causes of these accidents. The narrative descriptions of 180 stepladder-related fatalities were obtained from the U.S. Occupational Safety and Health Administration and were analyzed to identify the at-risk behaviors that preceded the fatality incidents. The results showed that most of the incidents should have been anticipated and could have been avoided. Unsafe practices such as improper lockout-tagout of electrical equipment, loss of balance, working on a folded stepladder, over-reaching, straddling the ladder, “walking” the ladder, poor footing, and unstable/shifting ladders, among others were identified. Virtually all of these fatalities could have been avoided by adhering to the guidelines posted on the stepladders and by complying with basic safe construction practices. 

  18. Factor structure of intelligence test battery KOG9

    Directory of Open Access Journals (Sweden)

    Lazarević Ljiljana B.

    2008-01-01

    Full Text Available Authors of Cybernetic model of cognitive functioning designed a battery of tests (KOG9, based on the model in order to assess cognitive efficiency. Authors assert that scale's factor structure comprises the three factors: perceptive, serial and parallel processing. Results of the previous research as well as the logical analysis of the origin and content of the tests suggested the possibility that more parsimonious two-factor solution can explain the structure of the correlations among them equally well. KOG9 battery was administered to 1116 students of Faculty of sport and physical education and students from Department of Psychology in order to study its latent structure. In spite of the fact that factor congruence analyses suggested higher robustness (cross-sample stability of the two-factor solution, results of both EFA and CFA spoke in favor of the three-factor solution. The problem of the lack of stability of the three-factor solution was located in not particularly well targeted choice of the markers of the efficacy of perceptual processing. The suggestion is to preserve the calculation of all three group scores, with some corrections. First of all, tests CF2 and/or GT7 should be replaced by some other perceptual test/tests of lower cognitive complexity. Some of the tests tapping parallel processing should be replaced by those more in line with the logic of the model.

  19. Structural stability of high entropy alloys under pressure and temperature

    DEFF Research Database (Denmark)

    Ahmad, Azkar S.; Su, Y.; Liu, S. Y.

    2017-01-01

    The stability of high-entropy alloys (HEAs) is a key issue before their selection for industrial applications. In this study, in-situ high-pressure and high-temperature synchrotron radiation X-ray diffraction experiments have been performed on three typical HEAs Ni20Co20Fe20Mn20Cr20, Hf25Nb25Zr25Ti......25, and Re25Ru25Co25Fe25 (at. %), having face-centered cubic (fcc), body-centered cubic (bcc), and hexagonal close-packed (hcp) crystal structures, respectively, up to the pressure of ∼80 GPa and temperature of ∼1262 K. Under the extreme conditions of the pressure and temperature, all three studied...... HEAs remain stable up to the maximum pressure and temperatures achieved. For these three types of studied HEAs, the pressure-dependence of the volume can be well described with the third order Birch-Murnaghan equation of state. The bulk modulus and its pressure derivative are found to be 88.3 GPa and 4...

  20. Structure activity relationships to assess new chemicals under TSCA

    Energy Technology Data Exchange (ETDEWEB)

    Auletta, A.E. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    Under Section 5 of the Toxic Substances Control Act (TSCA), manufacturers must notify the US Environmental Protection Agency (EPA) 90 days before manufacturing, processing, or importing a new chemical substance. This is referred to as a premanufacture notice (PMN). The PMN must contain certain information including chemical identity, production volume, proposed uses, estimates of exposure and release, and any health or environmental test data that are available to the submitter. Because there is no explicit statutory authority that requires testing of new chemicals prior to their entry into the market, most PMNs are submitted with little or no data. As a result, EPA has developed special techniques for hazard assessment of PMN chemicals. These include (1) evaluation of available data on the chemical itself, (2) evaluation of data on analogues of the PMN, or evaluation of data on metabolites or analogues of metabolites of the PMN, (3) use of quantitative structure activity relationships (QSARs), and (4) knowledge and judgement of scientific assessors in the interpretation and integration of the information developed in the course of the assessment. This approach to evaluating potential hazards of new chemicals is used to identify those that are most in need of addition review of further testing. It should not be viewed as a replacement for testing. 4 tabs.

  1. Sub-fragmentation of structural reactive material casings under explosion

    Science.gov (United States)

    Zhang, Fan; Gauthier, Maxime; Cojocaru, Cristian

    2017-01-01

    A concept of reactive hot spots intruded in a thick, structural reactive material casing was investigated to generate fine fragments for efficient energy release from casing material under explosive loading. This was achieved through distributing micro MoO3 particles into a granular Al casing, made by hot isostatic pressing, in a fuel-rich ratio of 10Al+MoO3. Reaction of Al and MoO3 during casing primary or secondary fragmentation creates heat and gas products to form micro-scale hot spots, whose expansion initiates local fractures leading to fine fragments of the rest of Al. Explosion experiments, using a 4.4 cm diameter cased charge with a casing-to-explosive mass ratio of 1.78 in a 2.1 m3 cylindrical chamber, demonstrated the presence of fine fragments and more efficient fragment combustion to augment air blast, as compared to a baseline pure Al-cased charge, thus indicating the feasibility of the concept.

  2. Crystal structure under pressure of geometrically frustrated pyrochlores

    Energy Technology Data Exchange (ETDEWEB)

    Apetrei, A [Laboratoire Leon Brillouin, CEA-CNRS, CE-Saclay, 91191 Gif-sur-Yvette (France); Mirebeau, I [Laboratoire Leon Brillouin, CEA-CNRS, CE-Saclay, 91191 Gif-sur-Yvette (France); Goncharenko, I [Laboratoire Leon Brillouin, CEA-CNRS, CE-Saclay, 91191 Gif-sur-Yvette (France); Crichton, W A [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France)

    2007-09-19

    We have studied by x-ray synchrotron diffraction under high pressure five pyrochlore compounds: Tb{sub 2}Ti{sub 2}O{sub 7} (up to 42 GPa), Tb{sub 2}Sn{sub 2}O{sub 7} and Tb{sub 2}Mo{sub 2}O{sub 7} (up to 35 GPa), Gd{sub 2}Mo{sub 2}O{sub 7} and (Tb{sub 0.8}La{sub 0.2}){sub 2}Mo{sub 2}O{sub 7} (up to 10 GPa). At ambient pressure all compounds crystallize in the cubic Fd3-barm symmetry group. This structure is stable for all compounds in the investigated pressure range. All three compounds having Mo as transition metal are described by the same equation of state, with the same bulk modulus B{sub 0} = 149. The bulk modulus is smaller in the Mo pyrochlores than in the Ti and Sn ones, in contrast with a priori expectations.

  3. Risk factors for ischemic stroke and transient ischemic attack in patients under age 50

    NARCIS (Netherlands)

    Janssen, A.W.M.; Leeuw, F.E. de; Janssen, M.C.H.

    2011-01-01

    To analyze risk factors for ischemic stroke and transient ischemic attack (TIA) in young adults under the age of 50. To make recommendations for additional research and practical consequences. From 97 patients with ischemic stroke or TIA under the age of 50, classical cardiovascular risk factors, co

  4. Investigating the influence of social desirability on personality factor structure.

    Science.gov (United States)

    Ellingson, J E; Smith, D B; Sackett, P R

    2001-02-01

    This study provides a comprehensive investigation into whether social desirability alters the factor structure of personality measures. The study brought together 4 large data sets wherein different organizational samples responded to different personality measures. This facilitated conducting 4 separate yet parallel investigations. Within each data set, individuals identified through a social desirability scale as responding in an honest manner were grouped together, and individuals identified as responding in a highly socially desirable manner were grouped together. Using various analyses, the fit of higher order factor structure models was compared across the 2 groups. Results were the same for each data set. Social desirability had little influence on the higher order factor structures that characterized the relationships among the scales of the personality measures.

  5. Using Multilevel Factor Analysis with Clustered Data: Investigating the Factor Structure of the Positive Values Scale

    Science.gov (United States)

    Huang, Francis L.; Cornell, Dewey G.

    2016-01-01

    Advances in multilevel modeling techniques now make it possible to investigate the psychometric properties of instruments using clustered data. Factor models that overlook the clustering effect can lead to underestimated standard errors, incorrect parameter estimates, and model fit indices. In addition, factor structures may differ depending on…

  6. Tissue factor activates allosteric networks in factor VIIa through structural and dynamic changes

    DEFF Research Database (Denmark)

    Madsen, Jesper Jonasson; Persson, E.; Olsen, O. H.

    2015-01-01

    Background: Tissue factor (TF) promotes colocalization of enzyme (factorVIIa) and substrate (FX or FIX), and stabilizes the active conformation of FVIIa. Details on how TF induces structural and dynamic changes in the catalytic domain of FVIIa to enhance its efficiency remain elusive. Objective...

  7. Structural Fingerprints of Transcription Factor Binding Site Regions

    Directory of Open Access Journals (Sweden)

    Peter Willett

    2009-03-01

    Full Text Available Fourier transforms are a powerful tool in the prediction of DNA sequence properties, such as the presence/absence of codons. We have previously compiled a database of the structural properties of all 32,896 unique DNA octamers. In this work we apply Fourier techniques to the analysis of the structural properties of human chromosomes 21 and 22 and also to three sets of transcription factor binding sites within these chromosomes. We find that, for a given structural property, the structural property power spectra of chromosomes 21 and 22 are strikingly similar. We find common peaks in their power spectra for both Sp1 and p53 transcription factor binding sites. We use the power spectra as a structural fingerprint and perform similarity searching in order to find transcription factor binding site regions. This approach provides a new strategy for searching the genome data for information. Although it is difficult to understand the relationship between specific functional properties and the set of structural parameters in our database, our structural fingerprints nevertheless provide a useful tool for searching for function information in sequence data. The power spectrum fingerprints provide a simple, fast method for comparing a set of functional sequences, in this case transcription factor binding site regions, with the sequences of whole chromosomes. On its own, the power spectrum fingerprint does not find all transcription factor binding sites in a chromosome, but the results presented here show that in combination with other approaches, this technique will improve the chances of identifying functional sequences hidden in genomic data.

  8. Factor-structure of economic growth in E-commerce

    Institute of Scientific and Technical Information of China (English)

    吴隽; 刘洪久; 栾天行

    2003-01-01

    In order to analyze the factors having effect on economic growth of E-commerce, the economic growthprocess of E-commerce is divided into three stages; growth stage, stabilization stage and re-growth stage. Thesethree different stages are analysed using several economic growth theories, a set of factor-structure is proposedfor each stage of the economic growth process of E-commerce.

  9. Structure of Plasmodium falciparum ADP-ribosylation factor 1

    Energy Technology Data Exchange (ETDEWEB)

    Cook, William J.; Smith, Craig D.; Senkovich, Olga; Holder, Anthony A.; Chattopadhyay, Debasish (UAB); (NIMR)

    2011-09-26

    Vesicular trafficking may play a crucial role in the pathogenesis and survival of the malaria parasite. ADP-ribosylation factors (ARFs) are among the major components of vesicular trafficking pathways in eukaryotes. The crystal structure of ARF1 GTPase from Plasmodium falciparum has been determined in the GDP-bound conformation at 2.5 {angstrom} resolution and is compared with the structures of mammalian ARF1s.

  10. [Structure and function of the factor VIII/von Willebrand factor complex].

    Science.gov (United States)

    Müller, G

    1990-03-01

    In the blood plasma factor VIII is bound to the von Willebrand factor. The primary structure of the two proteins were clarified by gene clonation. Factor VIII descends from a precursor protein with 2,351 amino acids by splitting of 19 amino acid residues and is activated by partial proteolysis. In the blood coagulation factor VIII acts as co-factor for the activation of factor X by factor IX in the presence of phospholipids and Ca++ within the intrinsic coagulation system. The formation of the von Willebrand factor takes place by splitting of 22 and 741 amino acid residues, respectively, from pre-pro-von Willebrand factor via pro-von Willebrand factor. The subunits of the von Willebrand factor consist od 2,050 amino acid residues. In the blood plasma the von Willebrand factor is existing as a mixture of multimeres. Receptors of the von Willebrand factor on the thrombocytic membrane are the glycoproteins GPIb and GPIIb/GPIIIa, by means of which the adhesion of thrombocytes at the subendoethelium of the vascular wall and the aggregation of thrombocytes are mediated.

  11. The structure of the nucleon: Elastic electromagnetic form factors

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, V. [Norfolk State University, Norfolk, VA (United States); Perdrisat, C.F.; Carlson, C.E. [The College of William and Mary, Williamsburg, VA (United States); Jones, M.K. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Brash, E.J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Christopher Newport University, Newport News, VA (United States)

    2015-07-15

    Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of the nucleon form factors are a test-bed for understanding how the nucleon's static properties and dynamical behavior emerge from QCD, the theory of the strong interactions between quarks. There has been enormous theoretical progress, since the publication of the Jefferson Lab proton form factor ratio data, aiming at reevaluating the picture of the nucleon. We will review the experimental and theoretical developments in this field and discuss the outlook for the future. (orig.)

  12. Structural Response Analysis under Dependent Variables Based on Probability Boxes

    National Research Council Canada - National Science Library

    Xiao, Z; Yang, G

    2015-01-01

      This paper considers structural response analysis when structural uncertainty parameters distribution cannot be specified precisely due to lack of information and there are complex dependencies in the variables...

  13. Interface stability of granular filter structures under currents

    NARCIS (Netherlands)

    Verheij, H.J.; Hoffmans, G.; Dorst, K.; Van de Sande, S.

    2012-01-01

    Granular filters are used for protection of structures against scour and erosion. For a proper functioning it is necessary that the interfaces between the filter structure, the subsoil and the water flowing above the filter structure are stable. Stability means that there is no transport of subsoil

  14. Interface stability of granular filter structures under currents

    NARCIS (Netherlands)

    Verheij, H.J.; Hoffmans, G.; Dorst, K.; Van de Sande, S.

    2012-01-01

    Granular filters are used for protection of structures against scour and erosion. For a proper functioning it is necessary that the interfaces between the filter structure, the subsoil and the water flowing above the filter structure are stable. Stability means that there is no transport of subsoil

  15. Latent Factor Structure of DSM-5 Posttraumatic Stress Disorder

    Science.gov (United States)

    Gentes, Emily; Dennis, Paul A.; Kimbrel, Nathan A.; Kirby, Angela C.; Hair, Lauren P.; Beckham, Jean C.; Calhoun, Patrick S.

    2015-01-01

    The current study examined the latent factor structure of posttraumatic stress disorder (PTSD) based on DSM-5 criteria in a sample of participants (N = 374) recruited for studies on trauma and health. Confirmatory factor analyses (CFA) were used to compare the fit of the previous 3-factor DSM-IV model of PTSD to the 4-factor model specified in DSM-5 as well as to a competing 4-factor “dysphoria” model (Simms, Watson, & Doebbeling, 2002) and a 5-factor (Elhai et al., 2011) model of PTSD. Results indicated that the Elhai 5-factor model (re-experiencing, active avoidance, emotional numbing, dysphoric arousal, anxious arousal) provided the best fit to the data, although substantial support was demonstrated for the DSM-5 4-factor model. Low factor loadings were noted for two of the symptoms in the DSM-5 model (psychogenic amnesia and reckless/self-destructive behavior), which raises questions regarding the adequacy of fit of these symptoms with other core features of the disorder. Overall, the findings from the present research suggest the DSM-5 model of PTSD is a significant improvement over the previous DSM-IV model of PTSD. PMID:26366290

  16. Latent Factor Structure of DSM-5 Posttraumatic Stress Disorder.

    Science.gov (United States)

    Gentes, Emily; Dennis, Paul A; Kimbrel, Nathan A; Kirby, Angela C; Hair, Lauren P; Beckham, Jean C; Calhoun, Patrick S

    The current study examined the latent factor structure of posttraumatic stress disorder (PTSD) based on DSM-5 criteria in a sample of participants (N = 374) recruited for studies on trauma and health. Confirmatory factor analyses (CFA) were used to compare the fit of the previous 3-factor DSM-IV model of PTSD to the 4-factor model specified in DSM-5 as well as to a competing 4-factor "dysphoria" model (Simms, Watson, & Doebbeling, 2002) and a 5-factor (Elhai et al., 2011) model of PTSD. Results indicated that the Elhai 5-factor model (re-experiencing, active avoidance, emotional numbing, dysphoric arousal, anxious arousal) provided the best fit to the data, although substantial support was demonstrated for the DSM-5 4-factor model. Low factor loadings were noted for two of the symptoms in the DSM-5 model (psychogenic amnesia and reckless/self-destructive behavior), which raises questions regarding the adequacy of fit of these symptoms with other core features of the disorder. Overall, the findings from the present research suggest the DSM-5 model of PTSD is a significant improvement over the previous DSM-IV model of PTSD.

  17. Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, J.C.; Huang, M.; Roth, D.A.; Furie, B.C.; Furie, B. (Wyeth); (MBL)

    2008-06-03

    Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca{sup 2+} and two Cu{sup 2+} ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

  18. Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

    Energy Technology Data Exchange (ETDEWEB)

    Chi Ki Ngo,J.; Huang, M.; Roth, D.; Furie, B.; Furie, B.

    2008-01-01

    Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca(2+) and two Cu(2+) ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

  19. Macro factors and the Term Structure of Interest Rates

    NARCIS (Netherlands)

    H.D.R. Dewachter (Hans); M. Lyrio (Marco)

    2003-01-01

    textabstractThis paper presents an essentially affine model of the term structure of interest rates making use of macroeconomic factors and their long-run expectations. The model extends the approach pioneered by Kozicki and Tinsley (2001) by modeling consistently long-run inflation expectations

  20. Factor Structure in Commodity Futures Return and Volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Lunde, Asger; Olesen, Kasper Vinther

    Using data on more than 750 million futures trades during 2004-2013, we analyze eight stylized facts of commodity price and volatility dynamics in the post financialization period. We pay particular attention to the factor structure in returns and volatility and to commodity market integration...... volatility indicates a nontrivial degree of market integration....

  1. Corporate financial structure, misallocation and total factor productivity

    NARCIS (Netherlands)

    Uras, R.B.

    2014-01-01

    This paper studies the quantitative relevance of the cross-sectional dispersion of corporate financial structure in explaining the intra-industry allocation efficiency of productive factors. I solve a heterogeneous firms model with financial constraints and distortions to the marginal rental-rate of

  2. Structural uncertainty in air mass factor calculation for NO

    NARCIS (Netherlands)

    Lorente Delgado, Alba; Folkert Boersma, K.; Yu, Huan; Dörner, Steffen; Hilboll, Andreas; Richter, Andreas; Liu, Mengyao; Lamsal, Lok N.; Barkley, Michael; Smedt, De Isabelle; Roozendael, Van Michel; Wang, Yang; Wagner, Thomas; Beirle, Steffen; Lin, Jin Tai; Krotkov, Nickolay; Stammes, Piet; Wang, Ping; Eskes, Henk J.; Krol, Maarten

    2017-01-01

    Air mass factor (AMF) calculation is the largest source of uncertainty in NO2 and HCHO satellite retrievals in situations with enhanced trace gas concentrations in the lower troposphere. Structural uncertainty arises when different retrieval methodologies are applied within the scientific community

  3. Structural and Discriminant Validity of the Career Factors Inventory

    Science.gov (United States)

    Dickinson, Josephine; Tokar, David M.

    2004-01-01

    Using a sample of 350 college students, this study examined the structural and discriminant validity of the Career Factors Inventory (CFI; Chartrand, Robbins, Morrill, & Boggs, 1990), a multidimensional measure of career indecision intended to be scored for two informational indecision components (Need for Career Information and Need for…

  4. Impact factors of fractal analysis of porous structure

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Characterization of pore structure is one of the key problems for fabrication and application research on porous materials. But, complexity of pore structure makes it difficult to characterize pore structure by Euclidean geometry and traditional experimental methods. Fractal theory has been proved effective to characterize the complex pore structure. The box dimension method based on fractal theory was applied to characterizing the pore structure of fiber porous materials by analyzing the electronic scanning microscope (SEM) images of the porous materials in this paper. The influences of image resolution, threshold value, and image magnification on fractal analysis were investigated. The results indicate that such factors greatly affect fractal analysis process and results. The appropriate magnification threshold and fractal analysis are necessary for fractal analysis.

  5. Factor analysis models for structuring covariance matrices of additive genetic effects: a Bayesian implementation

    Directory of Open Access Journals (Sweden)

    Gianola Daniel

    2007-09-01

    Full Text Available Abstract Multivariate linear models are increasingly important in quantitative genetics. In high dimensional specifications, factor analysis (FA may provide an avenue for structuring (covariance matrices, thus reducing the number of parameters needed for describing (codispersion. We describe how FA can be used to model genetic effects in the context of a multivariate linear mixed model. An orthogonal common factor structure is used to model genetic effects under Gaussian assumption, so that the marginal likelihood is multivariate normal with a structured genetic (covariance matrix. Under standard prior assumptions, all fully conditional distributions have closed form, and samples from the joint posterior distribution can be obtained via Gibbs sampling. The model and the algorithm developed for its Bayesian implementation were used to describe five repeated records of milk yield in dairy cattle, and a one common FA model was compared with a standard multiple trait model. The Bayesian Information Criterion favored the FA model.

  6. Factor Structure of the Conflict Tactics Scale 1

    Directory of Open Access Journals (Sweden)

    Kaori Baba

    2017-07-01

    Full Text Available Background: The Conflict Tactics Scale 1 (CTS1 is a widely used self-report measure of abusive attitudes of parents towards children. The factor structure of the CTS1 still remains to be clarified. The aim of this study was to examine the factor structure of the Japanese version of the CTS1 for postpartum women in community settings. Method: The data in this study came from the Okayama and Kumamoto’s study. These were part of a larger survey using longitudinal questionnaire studies conducted in Japan from 2001 to 2002 and in 2011, respectively. In both study sites, the participant mothers were asked to fill in the CTS1 one month after delivery when they attended for check-up at the out-patient clinic. Results: A total of 1,150 questionnaires were collected, excluding the participants with missing values in the CTS1. Finally, 1,078 were included in the statistical analyses. Data of 1,078 women were divided into two parts. In the first halved sample (n=578, an exploratory factor analysis was conducted for the CTS1 items after exluding nine items with extremely low prevalence. It revealed 2-factor or 3-factor models. Then, we conducted a model comparison with the second halved sample (n=500, using confirmatory factor analysis. In terms of goodness-of-fit indeces, the 2-factor model was superior. Its subscales were Reasoning and Psycholosical Aggression. Conclusion: The 2-factor model of the CTS1 consisting of Reasoning and Psychological Aggression was superior to the 3-factor model. This is not inconsistent with the original authors’ theoretical model.

  7. Factor Structure of Subjective Well-Being in Iran.

    Science.gov (United States)

    Joshanloo, Mohsen

    2016-01-01

    Subjective well-being is predominantly conceived as having 3 components: life satisfaction, positive affect, and negative affect. This article reports 2 studies that seek to investigate the factor structure of subjective well-being in Iran. One-, two-, and three-factor models of subjective well-being were evaluated using confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM). The results of Study 1 (N = 2,197) and Study 2 (N = 207) show that whereas the 1- and 2-factor models do not fit the data well, the 3-factor model provides an adequate fit. These results indicate that the 3 components of subjective well-being constitute 3 interrelated, yet distinct, factors. The analyses demonstrate how traditional CFA and ESEM can be combined to obtain a clear picture of the measurement model of subjective well-being and generate new insights about individual items and cross-loadings needed to derive more parsimonious measures. Nuances relating to the assessment of subjective well-being in more collectivist and Muslim countries are discussed.

  8. DYNAMIC ANALYSIS OF UNDERGROUND COMPOSITE STRUCTURES UNDER EXPLOSION LOADING

    Institute of Scientific and Technical Information of China (English)

    赵晓兵; 薛大为; 赵玉祥

    2004-01-01

    In selecting rational types of underground structures resisting explosion, in order to improve stress states of the structural section and make full use of material strength of each part of the section, the research method of composite structures is presented. Adopting the analysis method of micro-section free body, equilibrium equations, constraint equations and deformation coordination equations are given. Making use of the concept of generalized work and directly introducing Lagrange multiplier specific in physical meaning, the validity of the constructed generalized functional is proved by using variation method. The rational rigidity matching relationship of composite structure section is presented through example calculations.

  9. Factor selection and structural identification in the interaction ANOVA model.

    Science.gov (United States)

    Post, Justin B; Bondell, Howard D

    2013-03-01

    When faced with categorical predictors and a continuous response, the objective of an analysis often consists of two tasks: finding which factors are important and determining which levels of the factors differ significantly from one another. Often times, these tasks are done separately using Analysis of Variance (ANOVA) followed by a post hoc hypothesis testing procedure such as Tukey's Honestly Significant Difference test. When interactions between factors are included in the model the collapsing of levels of a factor becomes a more difficult problem. When testing for differences between two levels of a factor, claiming no difference would refer not only to equality of main effects, but also to equality of each interaction involving those levels. This structure between the main effects and interactions in a model is similar to the idea of heredity used in regression models. This article introduces a new method for accomplishing both of the common analysis tasks simultaneously in an interaction model while also adhering to the heredity-type constraint on the model. An appropriate penalization is constructed that encourages levels of factors to collapse and entire factors to be set to zero. It is shown that the procedure has the oracle property implying that asymptotically it performs as well as if the exact structure were known beforehand. We also discuss the application to estimating interactions in the unreplicated case. Simulation studies show the procedure outperforms post hoc hypothesis testing procedures as well as similar methods that do not include a structural constraint. The method is also illustrated using a real data example.

  10. Factor Selection and Structural Identification in the Interaction ANOVA Model

    Science.gov (United States)

    Post, Justin B.; Bondell, Howard D.

    2013-01-01

    Summary When faced with categorical predictors and a continuous response, the objective of analysis often consists of two tasks: finding which factors are important and determining which levels of the factors differ significantly from one another. Often times these tasks are done separately using Analysis of Variance (ANOVA) followed by a post-hoc hypothesis testing procedure such as Tukey’s Honestly Significant Difference test. When interactions between factors are included in the model the collapsing of levels of a factor becomes a more difficult problem. When testing for differences between two levels of a factor, claiming no difference would refer not only to equality of main effects, but also equality of each interaction involving those levels. This structure between the main effects and interactions in a model is similar to the idea of heredity used in regression models. This paper introduces a new method for accomplishing both of the common analysis tasks simultaneously in an interaction model while also adhering to the heredity-type constraint on the model. An appropriate penalization is constructed that encourages levels of factors to collapse and entire factors to be set to zero. It is shown that the procedure has the oracle property implying that asymptotically it performs as well as if the exact structure were known beforehand. We also discuss the application to estimating interactions in the unreplicated case. Simulation studies show the procedure outperforms post hoc hypothesis testing procedures as well as similar methods that do not include a structural constraint. The method is also illustrated using a real data example. PMID:23323643

  11. Further insights on the French WISC-IV factor structure through Bayesian structural equation modeling.

    Science.gov (United States)

    Golay, Philippe; Reverte, Isabelle; Rossier, Jérôme; Favez, Nicolas; Lecerf, Thierry

    2013-06-01

    The interpretation of the Wechsler Intelligence Scale for Children--Fourth Edition (WISC-IV) is based on a 4-factor model, which is only partially compatible with the mainstream Cattell-Horn-Carroll (CHC) model of intelligence measurement. The structure of cognitive batteries is frequently analyzed via exploratory factor analysis and/or confirmatory factor analysis. With classical confirmatory factor analysis, almost all cross-loadings between latent variables and measures are fixed to zero in order to allow the model to be identified. However, inappropriate zero cross-loadings can contribute to poor model fit, distorted factors, and biased factor correlations; most important, they do not necessarily faithfully reflect theory. To deal with these methodological and theoretical limitations, we used a new statistical approach, Bayesian structural equation modeling (BSEM), among a sample of 249 French-speaking Swiss children (8-12 years). With BSEM, zero-fixed cross-loadings between latent variables and measures are replaced by approximate zeros, based on informative, small-variance priors. Results indicated that a direct hierarchical CHC-based model with 5 factors plus a general intelligence factor better represented the structure of the WISC-IV than did the 4-factor structure and the higher order models. Because a direct hierarchical CHC model was more adequate, it was concluded that the general factor should be considered as a breadth rather than a superordinate factor. Because it was possible for us to estimate the influence of each of the latent variables on the 15 subtest scores, BSEM allowed improvement of the understanding of the structure of intelligence tests and the clinical interpretation of the subtest scores. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  12. Peak earthquake response of structures under multi-component excitations

    Institute of Scientific and Technical Information of China (English)

    Jianwei Song; Zach Liang; Yi-Lun Chu; George C.Lee

    2007-01-01

    Accurate estimation of the peak seismic responses of structures is important in earthquake resistant design.The internal force distributions and the seismic responses of structures are quite complex,since ground motions are multidirectional.One key issue is the uncertainty of the incident angle between the directions of ground motion and the reference axes of the structure.Different assumed seismic incidences can result in difierent peak values within the scope of design spectrum analysis for a given structure and earthquake ground motion record combination.Using time history analysis to determine the maximum structural responses excited by a given earthquake record requires repetitive calculations to determine the critical incident angle.This paper presents a transformation approach for relatively accurate and rapid determination of the maximum peak responses of a linear structure subjected to three-dimensional excitations within all possible seismic incident angles.The responses can be deformations,internal forces,strains and so on.An irregular building structure model is established using SAP2000 program.Several typical earthquake records and an artificial white noise are applied to the structure model to illustrate the variation of the maximum structural responses for different incident angles.Numerical results show that for many structural parameters,the variation can be greater than 100%.This method can be directly applied to time history analysis of structures using existing computer software to determine the peak responses without carrying out the analyses for all possible incident angles.It can also be used to verify and/or modify aseismic designs by using response spectrum analysis.

  13. The Factor Structure for Mental Rotations of Three-Dimensional Structures Represented in Diagrams.

    Science.gov (United States)

    Seddon, G. M.; And Others

    1985-01-01

    Determined the factor structure of tasks which require students to visualize how diagrams should be drawn to represent effects of rotating three-dimensional structures about the three Cartesian axes. Results obtained from 149 English and 231 Singapore students show that visualization about X-, Y-, and Z-axes are factorially distinct. (DH)

  14. Psychometric Structure of a Comprehensive Objective Structured Clinical Examination: A Factor Analytic Approach

    Science.gov (United States)

    Volkan, Kevin; Simon, Steven R.; Baker, Harley; Todres, I. David

    2004-01-01

    Problem Statement and Background: While the psychometric properties of Objective Structured Clinical Examinations (OSCEs) have been studied, their latent structures have not been well characterized. This study examines a factor analytic model of a comprehensive OSCE and addresses implications for measurement of clinical performance. Methods: An…

  15. Modeling solidification structure evolution and microsegregation under pressure condition

    Institute of Scientific and Technical Information of China (English)

    Qiang Li; Qiaoyi Guo; Rongde Li

    2006-01-01

    Solidification microstructure and microsegregation were simulated under a constant pressure condition using the cellular automaton method. First, a single dendrite evolution was simulated and compared under pressure condition and under normal condition,respectively. The solidification microstructure and microsegregation were then simulated. Through simulation, it may be concluded that if the growth direction of the dendrite is parallel to the pressure direction, dendrite growth will be hindered. On the other hand,pressure has no influence on the dendrite evolution. However, when two dendrites grow in close contact, solute enrichment occurs in the dendrites, which hinders the growth of the dendrites. In addition, the solute is preferentially enriched along the pressure direction.

  16. Structure factors in granular experiments with homogeneous fluidization.

    Science.gov (United States)

    Puglisi, Andrea; Gnoli, Andrea; Gradenigo, Giacomo; Sarracino, Alessandro; Villamaina, Dario

    2012-01-07

    Velocity and density structure factors are measured over a hydrodynamic range of scales in a horizontal quasi-2D fluidized granular experiment, with packing fractions φ ∈ [10%, 40%]. The fluidization is realized by vertically vibrating a rough plate, on top of which particles perform a Brownian-like horizontal motion in addition to inelastic collisions. On one hand, the density structure factor is equal to that of elastic hard spheres, except in the limit of large length-scales, as it occurs in the presence of an effective interaction. On the other hand, the velocity field shows a more complex structure which is a genuine expression of a non-equilibrium steady state and which can be compared to a recent fluctuating hydrodynamic theory with non-equilibrium noise. The temporal decay of velocity modes autocorrelations is compatible with linear hydrodynamic equations with rates dictated by viscous momentum diffusion, corrected by a typical interaction time with the thermostat. Equal-time velocity structure factors display a peculiar shape with a plateau at large length-scales and another one at small scales, marking two different temperatures: the "bath" temperature T(b), depending on shaking parameters, and the "granular" temperature T(g) < T(b), which is affected by collisions. The two ranges of scales are separated by a correlation length which grows with φ, after proper rescaling with the mean free path.

  17. Modeling Image Structure with Factorized Phase-Coupled Boltzmann Machines

    CERN Document Server

    Cadieu, Charles F

    2010-01-01

    We describe a model for capturing the statistical structure of local amplitude and local spatial phase in natural images. The model is based on a recently developed, factorized third-order Boltzmann machine that was shown to be effective at capturing higher-order structure in images by modeling dependencies among squared filter outputs (Ranzato and Hinton, 2010). Here, we extend this model to $L_p$-spherically symmetric subspaces. In order to model local amplitude and phase structure in images, we focus on the case of two dimensional subspaces, and the $L_2$-norm. When trained on natural images the model learns subspaces resembling quadrature-pair Gabor filters. We then introduce an additional set of hidden units that model the dependencies among subspace phases. These hidden units form a combinatorial mixture of phase coupling distributions, concentrated in the sum and difference of phase pairs. When adapted to natural images, these distributions capture local spatial phase structure in natural images.

  18. Performance based investigations of structural systems under fire

    DEFF Research Database (Denmark)

    Gentili, Filippo; Crosti, Chiara; Giuliani, Luisa

    2010-01-01

    Prescriptive measures and procedures developed over the past here are mostly aimed at preventing structural failures of single elements for the time required for the evacuation. The response to fire and fire effects of the structural system as a whole remains often unknown and the survival...... of the construction after this time cannot always be granted. This is even more true in case of unaccounted events like human errors or rare but severe occurrence like a fire after explosion, which cannot be contemplated in the usual design. Even if a structure could be hardly designed to resist fully integer all...... these kinds of events, the mitigation of possible collapse induced by fire should be achieved. In this respect, a performance-based investigation of the structure aimed at highlight fire effects and fire-induced collapse mechanisms becomes of interest. In the paper collapse mechanisms of some simple...

  19. VIABILITY SOLUTIONS TO STRUCTURED HAMILTON-JACOBI EQUATIONS UNDER CONSTRAINTS

    OpenAIRE

    2011-01-01

    International audience; Structured Hamilton-Jacobi partial differential equations are Hamilton-Jacobi equations where the time variable is replaced by a vector-valued variable "structuring" the system. It could be the time-age pair (Hamilton-Jacobi-McKendrick equations) or candidates for initial or terminal conditions (Hamilton-Jacobi-Cournot equations) among a manifold of examples. Here, we define the concept of "viability solution" which always exists and can be computed by viability algori...

  20. Commercial Mortgage Prepayments Under Heterogeneous Prepayment Penalty Structures

    OpenAIRE

    Qiang Fu; Michael LaCour-Little; Kerry D. Vandell

    2003-01-01

    Much of the literature on pricing commercial mortgages and commercial mortgage-backed securities has assumed homogeneity in prepayment penalty structure. In this paper, we provide evidence that such an assumption is inappropriate and examine the effect of penalty structures observed in actual contracts. After conducting preliminary simulations, we present hazard models estimated from data on 1,165 multifamily mortgage loans to show how empirical prepayment rates vary with alternative penalty ...

  1. Turing patterns and solitary structures under global control

    CERN Document Server

    Pismen, L M

    1994-01-01

    Striped Turing patterns and solitary band and disk structures are constructed using a three-variable multiscale model with cubic nonlinearity and global control. The existence and stability conditions of regular structures are analysed using the equation of motion of curved boundaries between alternative states of the short-range component. The combined picture of transitions between striped and spotted patterns with changing level of global control is in qualitative agreement with the results of the computer experiment by Middya and Luss

  2. Damage detection in composite structures using vibration response under stochastic excitation

    Science.gov (United States)

    Yang, Zhichun; Wang, Le; Wang, Hui; Ding, Yan; Dang, Xiaojuan

    2009-09-01

    The investigations in damage detection methods based on vibration response are reviewed according to two categories, i.e. model-based damage detection method (MBDDM) and non-model-based damage detection method (NMBDDM). Then a new concept of inner product vector (IPV) is introduced using the cross correlation function of the measured vibration responses of the structure, and the corresponding damage detection method is proposed based on this vector. It is theoretically proved that the elements in IPV of a structure is the inner product of the time domain vibration responses of corresponding measurement points, and this vector can be directly calculated using the measured time domain vibration responses. Under white noise excitation the IPV of a structure is a weighted summation of mode shapes of the structure, and the weighted factors of the summation only depend on modal parameters of the structure. The effect of measurement noise on IPV is also considered, and the effect can be eliminated by the definition of IPV and an interpolation technique. The difference of IPVs between the intact and damaged structure is adopted as the damage index, and damage location is determined by the abrupt change in the difference of IPV. In order to distinguish the abrupt change caused by structural damage and measurement noise, two thresholds are proposed to classify the damaged and intact structures. Numerical simulation results of damage detection of single-location and multi-location delamination in a composite laminate beam demonstrate the effectiveness and veracity of the proposed method, even though measurement noise is considered in the vibration responses.

  3. Seismic Analysis of Structures under Different Soil Conditions

    Directory of Open Access Journals (Sweden)

    Ranu R. Akulwar

    2015-01-01

    Full Text Available In India, multi-storied buildings are usually constructed due to high cost and scarcity of land. In order to utilize maximum land area, builders and architects generally propose asymmetrical plan configurations. These asymmetrical plan buildings, which are constructed in seismic prone areas, are likely to be damaged during earthquake. Earthquake is a natural phenomenon which can generate the most destructive forces on structures. Buildings should be made safe for lives by proper design and detailing of structural members in order to have a ductile form of failure. The concept of earthquake resistant design is that the building should be designed to resist the forces, which arises due to Design Basis Earthquake, with only minor damages and the forces, which arises due to Maximum Considered Earthquake, with some accepted structural damages but no collapse. This project report comprises of seismic analysis and design of an five-storied R.C. building with asymmetrical plan in different soil conditions. The building is modelled as a 3D space frame with six degrees of freedom at each node using the software SAP2000 v 14. Building is analyzed using Response Spectrum method. The Response Spectra as per IS 1893 (Part 1: 2002 for rocky or hard soil and soft soil is used. Dynamic response of a structure resting on soft soils in particular, may differ substantially in amplitude and frequency content from the response of an identical structure supported on a very stiff soil or rock. However, data on many failure examples of rigid structures resting on flexible soils and intensive analytical studies in recent years have made considerable advances in the field of soil-structure interaction and analytical techniques are now available. This interaction phenomenon is principally affected by the mechanism of energy exchanged between soil and the structure. Considering the soil – structure interaction effect which is mainly due to the fact that buildings with

  4. Bacterial Sigma Factors and Anti-Sigma Factors: Structure, Function and Distribution

    Directory of Open Access Journals (Sweden)

    Mark S. Paget

    2015-06-01

    Full Text Available Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP that play critical roles in transcription initiation, including the recognition and opening of promoters as well as the initial steps in RNA synthesis. This review focuses on the structure and function of the major sigma-70 class that includes the housekeeping sigma factor (Group 1 that directs the bulk of transcription during active growth, and structurally-related alternative sigma factors (Groups 2–4 that control a wide variety of adaptive responses such as morphological development and the management of stress. A recurring theme in sigma factor control is their sequestration by anti-sigma factors that occlude their RNAP-binding determinants. Sigma factors are then released through a wide variety of mechanisms, often involving branched signal transduction pathways that allow the integration of distinct signals. Three major strategies for sigma release are discussed: regulated proteolysis, partner-switching, and direct sensing by the anti-sigma factor.

  5. The Journal Impact Factor is under attack - use the CAPCI factor instead.

    Science.gov (United States)

    Diamandis, Eleftherios P

    2017-01-16

    The uses and misuses of the Journal Impact Factor (JIF) have been thoroughly discussed in the literature. A few years ago, I predicted that JIF would soon be replaced, while another colleague argued the opposite. Over the past few months, attacks on JIF have intensified, with some publishing organizations gradually removing the indicator from their journals' websites. Here, I argue that most, if not all of the misuses of JIF are related to its name. The word "impact" should be removed, since it implies an influential attribute, either for the journals, their published papers, or their authors. I propose instead the use of a new name, the "CAPCI factor", standing for Citation Average Per Citable Item, which accurately describes what is represented by this measure.

  6. Structural convergence of maize and wheat straw during two-year decomposition under different climate conditions.

    Science.gov (United States)

    Wang, Xiaoyue; Sun, Bo; Mao, Jingdong; Sui, Yueyu; Cao, Xiaoyan

    2012-07-03

    Straw decomposition plays an important role in soil carbon sequestration. Litter quality and climate condition are considered to be key factors that regulate straw decomposition. This study investigated the decomposition characteristics of wheat and maize straw under cold temperate, warm temperate, and midsubtropic climate conditions, and examined whether the chemical structures of straw residues became similar during decomposition under different climate conditions. Straws were put in 0.074-mm-mesh size litter bags to exclude soil fauna and buried in black soil plots at three experimental stations located in the aforementioned climate regions to rule out the impact of soil type. The decomposition rate constants of wheat straw and maize straw increased linearly with temperature, and the former was more sensitive to temperature. Climate conditions and straw quality had marked effects on the residual material structure in the first half year of decomposition, but then decreased. Wheat and maize straw showed common decomposition characteristics with a decrease of O/N-alkyl carbons and di-O-alkyls, and a simultaneous increase of alkyl carbons, aromatic carbons, aromatic C-O groups, and COO/N-C ═ O groups. Overall, the results indicated that the chemical compositions of the two types of straw became similar after 2-year decomposition under different climate conditions.

  7. SEISMIC RANDOM VIBRATION ANALYSIS OF STOCHASTIC STRUCTURES USING RANDOM FACTOR METHOD

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Seismic random vibration analysis of stochastic truss structures is presented. A new method called random factor method is used for dynamic analysis of structures with uncertain parameters, due to variability in their material properties and geometry. Using the random factor method, the natural frequencies and modeshapes of a stochastic structure can be respectively described by the product of two parts, corresponding to the random factors of the structural parameters with uncertainty, and deterministic values of the natural frequencies and modeshapes obtained by conventional finite element analysis. The stochastic truss structure is subjected to stationary or non-stationary random earthquake excitation. Computational expressions for the mean and standard deviation of the mean square displacement and mean square stress are developed by means of the random variable's functional moment method and the algebra synthesis method. An antenna and a truss bridge are used as practical engineering examples to illustrate the application of the random factor method in the seismic response analysis of random structures under stationary or non-stationary random earthquake excitation.

  8. Educational achievement, personality, and behavior: assessment, factor structure and implications for theory and practice.

    Science.gov (United States)

    Gaffney, Tim W; Perryman, Cassandra

    2012-01-01

    The purposes of this research were to first examine the evidence regarding the factor structure of educational achievement tests in the context of two theoretical models of cognitive ability (psychometric g and mutualism) that have been proposed to explain this structure as well as the underlying processes that may be responsible for its emergence in dimensionality studies. Then, the factor structure underlying a sample of the standardized educational achievement tests used by California in its statewide school accountability program was compared to those emerging from a selection of behavioral and personality assessments. As expected, the educational achievement tests exhibited a strong and uniformly positive manifold resulting in greater unidimensionality as evidenced by a dominant general factor in bi-factor analysis then either the personality or behavioral assessments. The implications of these structural differences are discussed with respect to the two theoretical perspective as well as in the context of formative and summative educational inferences in particular, and the school accountability and reform movement in general.

  9. Structure Under the Bushveld Complex, South Africa from Receiver Functions

    Science.gov (United States)

    Castillo, B. A.

    2015-12-01

    The Bushveld Igneous Complex (BIC) is the largest layered mafic intrusion on Earth and formed within Transvaal Basin in South Africa. The hypothesis that the limbs of the Rustenburg layer of the BIC are connected at depth is tested using teleseimic events of Mw > 5.5 to provide data under a seismic station (receiver) in the western limb of the BIC. Receiver functions have been computed from the data in order to image the layering under the Bushveld Complex. The receiver functions show discrete arrivals from the mafic layers, the Transvaal sediments under the BIC, and the Mohorovicic discontinuity at the base of the crust.. An interactive forward modeling method has been used to model the receiver functions in order to estimate the thickness of the BIC and the crust. Results show a BIC that is about 5-8 km thick and a Moho at ~40 km depth.

  10. Asymmetric flexural behavior from bamboo's functionally graded hierarchical structure: underlying mechanisms.

    Science.gov (United States)

    Habibi, Meisam K; Samaei, Arash T; Gheshlaghi, Behnam; Lu, Jian; Lu, Yang

    2015-04-01

    As one of the most renewable resources on Earth, bamboo has recently attracted increasing interest for its promising applications in sustainable structural purposes. Its superior mechanical properties arising from the unique functionally-graded (FG) hierarchical structure also make bamboo an excellent candidate for bio-mimicking purposes in advanced material design. However, despite its well-documented, impressive mechanical characteristics, the intriguing asymmetry in flexural behavior of bamboo, alongside its underlying mechanisms, has not yet been fully understood. Here, we used multi-scale mechanical characterizations assisted with advanced environmental scanning electron microscopy (ESEM) to investigate the asymmetric flexural responses of natural bamboo (Phyllostachys edulis) strips under different loading configurations, during "elastic bending" and "fracture failure" stages, with their respective deformation mechanisms at microstructural level. Results showed that the gradient distribution of the vascular bundles along the thickness direction is mainly responsible for the exhibited asymmetry, whereas the hierarchical fiber/parenchyma cellular structure plays a critical role in alternating the dominant factors for determining the distinctly different failure mechanisms. A numerical model has been likewise adopted to validate the effective flexural moduli of bamboo strips as a function of their FG parameters, while additional experiments on uniaxial loading of bamboo specimens were performed to assess the tension-compression asymmetry, for further understanding of the microstructure evolution of bamboo's outer and innermost layers under different bending states. This work could provide insights to help the processing of novel bamboo-based composites and enable the bio-inspired design of advanced structural materials with desired flexural behavior.

  11. Factor structure of the SOCRATES questionnaire in hospitalized medical patients.

    Science.gov (United States)

    Bertholet, Nicolas; Dukes, Kim; Horton, Nicholas J; Palfai, Tibor P; Pedley, Alison; Saitz, Richard

    2009-01-01

    The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES), a 19-item instrument developed to assess readiness to change alcohol use among individuals presenting for specialized alcohol treatment, has been used in various populations and settings. Its factor structure and concurrent validity has been described for specialized alcohol treatment settings and primary care. The purpose of this study was to determine the factor structure and concurrent validity of the SOCRATES among medical inpatients with unhealthy alcohol use not seeking help for specialized alcohol treatment. The subjects were 337 medical inpatients with unhealthy alcohol use, identified during their hospital stay. Most of them had alcohol dependence (76%). We performed an Alpha Factor Analysis (AFA) and Principal Component Analysis (PCA) of the 19 SOCRATES items, and forced 3 factors and 2 components, in order to replicate findings from Miller and Tonigan (Miller, W. R., & Tonigan, J. S., (1996). Assessing drinkers' motivations for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). Psychology of Addictive Behavior, 10, 81-89.) and Maisto et al. (Maisto, S. A., Conigliaro, J., McNeil, M., Kraemer, K., O'Connor, M., & Kelley, M. E., (1999). Factor structure of the SOCRATES in a sample of primary care patients. Addictive Behavior, 24(6), 879-892.). Our analysis supported the view that the 2 component solution proposed by Maisto et al. (Maisto, S.A., Conigliaro, J., McNeil, M., Kraemer, K., O'Connor, M., & Kelley, M.E., (1999). Factor structure of the SOCRATES in a sample of primary care patients. Addictive Behavior, 24(6), 879-892.) is more appropriate for our data than the 3 factor solution proposed by Miller and Tonigan (Miller, W. R., & Tonigan, J. S., (1996). Assessing drinkers' motivations for change: The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). Psychology of Addictive Behavior, 10, 81-89.). The first component measured

  12. 上海未婚青少年性相关行为影响因素结构方程模型分析%Analysis on Factors Influencing Adolescent Sex-related Behaviors in Shanghai City under the Structural Equation Model

    Institute of Scientific and Technical Information of China (English)

    张鹏; 楼超华; Laurie; 高尔生

    2011-01-01

    Objective To explore the direct and indirect effect of influencing factors on adolescent sex-related behaviors under the structural equation model based on KAB model. Methods A Computer-assisted Self Interview (CASI) questionnaire survey was conducted to collect sexrelated information about knowledge,attitude and behaviors from 6 299 unmarried adolescents aged 15 to 24 in Shanghai city. The structural equation model was based on data. And the final model was determined in terms of parameter test and necessary modification. Results Knowledge score of reproduction and contraception was relatively low, and the pass rate was 28. 6%. About 75% of male and about 55% of female accepted the premarital sexual behavior. The goodness of fit for the structural equation mode1 was satisfying. The knowledge of sex and production has direct effect (0.2) and indirect effect(0. 1176) on the sex-related behaviors of adolescents. The total effect of knowledge was 0. 3176. Permissive sexual attitude (0. 28 ) was the promoting factor for adolescent sex-related behaviors.Conclusion We should strengthen comprehensive and formal sex education such as sexual health,reproduction and contraception for adolescents,and promote them to change their sexual attitude and decrease the risk of sex-related behaviors.%目的 在健康促进知信行理论的基础上构建青少年性相关行为影响因素的结构方程模型,探讨其影响因素的直接作用和间接作用.方法 用计算机辅助调查6 299名15~24岁未婚青少年性与生殖健康知识、性相关态度和性相关行为,对调查数据进行结构方程模型拟合,再根据模型参数检验,通过评价修正确定最终模型.结果 青少年生殖避孕知识得分较低,及格率为28.6%.大约75%的男性和55%的女性接受婚前性行为.结构方程模型拟合较好,性与生殖健康知识对性相关行为的直接作用为0.2,间接作用为0.1176,总作用为0.3176.开放的性相关态度对

  13. Factors associated with asthma among under-fives in Mulago hospital, Kampala Uganda

    DEFF Research Database (Denmark)

    Nantanda, Rebecca; Ostergaard, Marianne S; Ndeezi, Grace

    2013-01-01

    Asthma is the most common chronic childhood illness, with rapidly increasing prevalence in low-income countries. Among young children, asthma is often under-diagnosed.We investigated the factors associated with asthma among under-fives presenting with acute respiratory symptoms at Mulago hospital...

  14. Harvesting Energy from Vibrations of the Underlying Structure

    DEFF Research Database (Denmark)

    Han, Bo; Vssilaras, S; Papadias, C.B.

    2013-01-01

    on the type of power supply. No matter how energy efficient the operation of a battery operated sensor is, the energy of the battery will be exhausted at some point. In order to achieve a virtually unlimited lifetime, the sensor node should be able to recharge its battery in an easy way. Energy harvesting...... emerges as a technique that can harvest energy from the surrounding environment. Among all possible energy harvesting solutions, kinetic energy harvesting seems to be the most convenient, especially for sensors placed on structures that experience regular vibrations. Such micro-vibrations can be harmful...... to the long-term structural health of a building or bridge, but at the same time they can be exploited as a power source to power the wireless sensors that are monitoring this structural health. This paper presents a new energy harvesting method based on a vibration driven electromagnetic harvester. By using...

  15. Modeling of fracture of protective concrete structures under impact loads

    Energy Technology Data Exchange (ETDEWEB)

    Radchenko, P. A., E-mail: radchenko@live.ru; Batuev, S. P.; Radchenko, A. V.; Plevkov, V. S. [Tomsk State University of Architecture and Building, Tomsk, 634003 (Russian Federation)

    2015-10-27

    This paper presents results of numerical simulation of interaction between a Boeing 747-400 aircraft and the protective shell of a nuclear power plant. The shell is presented as a complex multilayered cellular structure consisting of layers of concrete and fiber concrete bonded with steel trusses. Numerical simulation was performed three-dimensionally using the original algorithm and software taking into account algorithms for building grids of complex geometric objects and parallel computations. Dynamics of the stress-strain state and fracture of the structure were studied. Destruction is described using a two-stage model that allows taking into account anisotropy of elastic and strength properties of concrete and fiber concrete. It is shown that wave processes initiate destruction of the cellular shell structure; cells start to destruct in an unloading wave originating after the compression wave arrival at free cell surfaces.

  16. Soil Structure Interaction between Two Adjacent Buildings under Earthquake Load

    Directory of Open Access Journals (Sweden)

    Mahmoud Yahyai

    2008-01-01

    Full Text Available In some cases, tall buildings are located in geotechnically unsuitable places, due to their high ratio of height to width; there is risk of uplift and other effects such as overturning and reduction structure serviceability during earthquake. This research is aimed to evaluate the effect of Soil-Structure Interaction (SSI on seismic behavior of two adjacent 32 story buildings such as time period, base shear and displacements. The interaction effects are investigated for variable distance between the two buildings. Three types of soil such as soft clay, sandy gravel and compacted sandy gravel are considered for this study. The result obtained that the interaction effect increases time period of both buildings base shear and lateral displacement of the structures increases.

  17. Tuned mass absorbers on damped structures under random load

    DEFF Research Database (Denmark)

    Krenk, Steen; Høgsberg, Jan Becker

    2008-01-01

    A substantial literature exists on the optimal choice of parameters of a tuned mass absorber on a structure excited by a force or by ground acceleration with random characteristics in the form of white noise. In the absence of structural damping the optimal frequency tuning is determined from...... the mass ratio alone, and the damping can be determined subsequently. Only approximate results are available for the influence of damping in the original structure, typically in the form of series expansions. In the present paper it is demonstrated that for typical mass ratios in the order of a few percent...... the classic stochastic frequency tuning gives the same standard deviation of the response amplitude within a margin of 0.001 as when using the classic frequency tuning for harmonic load variation, and then optimizing the damping separately. Simple approximate, but very accurate, expressions are obtained...

  18. Deformation of wrinkled membrane inflatable structures under concentrated loads

    Institute of Scientific and Technical Information of China (English)

    WANG Chang-guo; DU Xing-wen; WAN Zhi-min; HE Xiao-dong

    2008-01-01

    The axisymmetric deformation of a paraboloidal membrane inflatable structure subjected to a concentrated load at its apex and a uniform intemal pressure was analyzed.The wrinkle angle was obtained according to the membrane theory when wrinkles appeared and determined the wrinkle region.The wrinkled deformation was obtained based on the relaxed energy function.The effects of inflation pressure and concentrated loads on the wrinkle ansle were analyzed and the deformation Was obtained at the apex of structure.According to the numerical analysis,the shape of deformed meridians with wrinkles Was obtained.

  19. Harvesting Energy from Vibrations of the Underlying Structure

    DEFF Research Database (Denmark)

    Han, Bo; Vssilaras, S; Papadias, C.B.

    2013-01-01

    The use of wireless sensors for structural health monitoring offers several advantages such as small size, easy installation and minimal intervention on existing structures. However the most significant concern about such wireless sensors is the lifetime of the system, which depends heavily...... on the type of power supply. No matter how energy efficient the operation of a battery operated sensor is, the energy of the battery will be exhausted at some point. In order to achieve a virtually unlimited lifetime, the sensor node should be able to recharge its battery in an easy way. Energy harvesting...

  20. AFM Structural Characterization of Drinking Water Biofilm under Physiological Conditions

    Science.gov (United States)

    Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air...

  1. AFM Structural Characterization of Drinking Water Biofilm under Physiological Conditions

    Science.gov (United States)

    Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air...

  2. Monitoring and restabilizing structures under external excitations through detection and prediction of changes in structural properties

    Science.gov (United States)

    Sebastijanovic, Nebojsa

    The primary goal of this dissertation is the development of methods for prediction and detection of damage in structures under external excitations through the use of sensors and actuators. The first example involves developing an active flutter suppression algorithm for a flat panel in flight and space vehicles using embedded piezoceramic actuators. A basic eigenvector orientation approach is used to evaluate the possibility of controlling the onset of panel flutter. Eigenvectors for two consecutive modes are usually orthogonal and the onset of flutter condition can be observed earlier as they start to lose their orthogonality. Piezoelectric layers are assumed to be bonded to the top and bottom surfaces of the panel in order to provide counter-bending moments at joints between elements. The controllers are designed to modify the stiffness of the structure and re-stabilize the system; as a result, flutter occurrence can be offset to a higher flutter speed. To illustrate the applicability and effectiveness of the developed method, several simple wide beam examples using piezoelectric layers as actuators are studied and presented. Controllers based on different control objectives are considered and the effects of control moment locations are studied. Potential applications of this basic method may be straightforwardly applied to plate and shell structures of laminated composites. The second example includes developing a method for detecting, locating, and quantifying structural damage using acceleration measurements as feedback. This method directly uses time domain structural vibration measurements and the effects of different damages are decoupled in the controller design. The effectiveness of the proposed method is evaluated with illustrative examples of a three and an eight-story model as well as a single story steel frame model with changes in joint flexibility. Finally, the progress on developing a hybrid structural health monitoring system is presented through

  3. Performance based investigations of structural systems under fire

    DEFF Research Database (Denmark)

    Gentili, Filippo; Crosti, Chiara; Giuliani, Luisa

    2010-01-01

    of the construction after this time cannot always be granted. This is even more true in case of unaccounted events like human errors or rare but severe occurrence like a fire after explosion, which cannot be contemplated in the usual design. Even if a structure could be hardly designed to resist fully integer all...

  4. Structures of water molecules in carbon nanotubes under electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Winarto,; Takaiwa, Daisuke; Yamamoto, Eiji; Yasuoka, Kenji, E-mail: yasuoka@mech.keio.ac.jp [Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2015-03-28

    Carbon nanotubes (CNTs) are promising for water transport through membranes and for use as nano-pumps. The development of CNT-based nanofluidic devices, however, requires a better understanding of the properties of water molecules in CNTs because they can be very different from those in the bulk. Using all-atom molecular dynamics simulations, we investigate the effect of axial electric fields on the structure of water molecules in CNTs having diameters ranging from (7,7) to (10,10). The water dipole moments were aligned parallel to the electric field, which increases the density of water inside the CNTs and forms ordered ice-like structures. The electric field induces the transition from liquid to ice nanotubes in a wide range of CNT diameters. Moreover, we found an increase in the lifetime of hydrogen bonds for water structures in the CNTs. Fast librational motion breaks some hydrogen bonds, but the molecular pairs do not separate and the hydrogen bonds reform. Thus, hydrogen bonds maintain the water structure in the CNTs, and the water molecules move collectively, decreasing the axial diffusion coefficient and permeation rate.

  5. Term Structure of Credit Spreads of A Firm When Its Underlying Assets are Discontinuous

    Directory of Open Access Journals (Sweden)

    Budhi Arta Surya

    2012-01-01

    Full Text Available We revisit the previous works of Leland [12], Leland and Toft [11] andHilberink and Rogers [7] on optimal capital structure and show that thecredit spreads of short-maturity corporate bonds can have nonzero valueswhen the underlying of the firm’s assets value has downward jumps. We givean analytical treatment of this fact under a general Levy process and discusssome numerical examples under pure jump processes.Keywords: Optimal capital structure, credit risk, term structure of creditspread

  6. Structural studies of lamellar surfactant systems under shear

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Recent experimental studies on concentrated surfactant systems are reviewed. Particular attention is focused on the transformation from planar lamellar sheets to multilamellar vesicles. It is discussed whether both of these states are thermodynamic stable, or if the MLV is an artifact of shear...... induced factors. Recent studies includes the dependence on shear, and dependence on salt and cosurfactants, and thereby related lamellar defects. The review include moreover the demonstration that polymeric amphiphiles dramatically enhance the quality of classical surfactants. (C) 2001 Elsevier Science...

  7. Dynamic response analysis of structure under time-variant interval process model

    Science.gov (United States)

    Xia, Baizhan; Qin, Yuan; Yu, Dejie; Jiang, Chao

    2016-10-01

    Due to the aggressiveness of the environmental factor, the variation of the dynamic load, the degeneration of the material property and the wear of the machine surface, parameters related with the structure are distinctly time-variant. Typical model for time-variant uncertainties is the random process model which is constructed on the basis of a large number of samples. In this work, we propose a time-variant interval process model which can be effectively used to deal with time-variant uncertainties with limit information. And then two methods are presented for the dynamic response analysis of the structure under the time-variant interval process model. The first one is the direct Monte Carlo method (DMCM) whose computational burden is relative high. The second one is the Monte Carlo method based on the Chebyshev polynomial expansion (MCM-CPE) whose computational efficiency is high. In MCM-CPE, the dynamic response of the structure is approximated by the Chebyshev polynomials which can be efficiently calculated, and then the variational range of the dynamic response is estimated according to the samples yielded by the Monte Carlo method. To solve the dependency phenomenon of the interval operation, the affine arithmetic is integrated into the Chebyshev polynomial expansion. The computational effectiveness and efficiency of MCM-CPE is verified by two numerical examples, including a spring-mass-damper system and a shell structure.

  8. Statistical Structures Underlying Quantum Mechanics and Social Science

    CERN Document Server

    Wright, R

    2003-01-01

    Common observations of the unpredictability of human behavior and the influence of one question on the answer to another suggest social science experiments are probabilistic and may be mutually incompatible with one another, characteristics attributed to quantum mechanics (as distinguished from classical mechanics). This paper examines this superficial similarity in depth using the Foulis-Randall Operational Statistics language. In contradistinction to physics, social science deals with complex, open systems for which the set of possible experiments is unknowable and outcome interference is a graded phenomenon resulting from the ways the human brain processes information. It is concluded that social science is, in some ways, "less classical" than quantum mechanics, but that generalized "quantum" structures may provide appropriate descriptions of social science experiments. Specific challenges to extending "quantum" structures to social science are identified.

  9. Modelling of composites materials and structures under hydrodynamic ram loading

    OpenAIRE

    Deletombe, E.

    2013-01-01

    The impact of high speed/high energy projectiles - possibly ballistic ones - and the occurrence of an hydraulic ram (HRAM) event in fuel tanks, constitutes a threat which is often legitimized if not always compulsory to consider for aircraft safety. To prevent from such an eventuality, the impact hardening through armouring the structure is an ultimate solution which is hardly acceptable in aeronautics for obvious mass penalty reasons. The reduction of fuel tanks vulnerability then turns to b...

  10. UHPC SANDWICH STRUCTURES WITH COMPOSITE COATING UNDER COMPRESSIVE LOAD

    Directory of Open Access Journals (Sweden)

    Jan Markowski

    2016-12-01

    Full Text Available Ultra-high-performance concrete (UHPC sandwich structures with composite coating serve as multipurpose load-bearing elements. The UHPC’s extraordinary compressive strength is used in a multi-material construction element, while issues regarding the concrete’s brittle failure behaviour are properly addressed. A hollow section concrete core is covered by two steel tubes. The outer steel tube is wrapped in a composite material. By this design, UHPC is used in a material- and shape-optimised way with a low dead weight ratio[1] concerning the load-bearing capacity and stability[2]. The cross-section’s hollow shape optimises the construction’s buckling stability while saving self-weight. The composite coating on the column’s outside functions both as a layer increasing the construction’s durability and as a structural component increasing the the maximum and the residual load capacity. Investigations on the construction’s structural behaviour were performed.

  11. Acoustic emissions in granular structures under gravitational destabilization

    Science.gov (United States)

    Thirot, J.-L.; Le Gonidec, Y.; Kergosien, B.

    2012-05-01

    In this work, we perform experiments in an acoustic tank to record acoustic emissions (AEs) occurring when a granular medium is submitted to a gravitational destabilization. The granular medium is composed of monodisperse glass beads filling a box which can be inclined from α=0° up to the avalanche threshold angle α0=28°. To respect quasi-static conditions, the angle increases by steps less than 3°/mn. An omnidirectional hydrophone records the continuous acoustic field in the bead structure until the avalanche occurs. We compare the results for different experimental configurations, in particular for dry and water saturated granular media, but also for different bead diameters (d=8, 3 and 0.3 mm) in order to span the viscosity range of the granular structure. We show that the AE signatures strongly depend on the viscosity parameter, which can be related to the Stokes number and the fluid/solid density ratio. The transition from a viscous to an inertial dynamic of the granular structure is discussed, based on these experimental results.

  12. Defect Physics of Structural Materials under Extreme Conditions

    Science.gov (United States)

    Stocks, G. Malcolm

    2010-03-01

    ``Crystals are like people: it is the defects in them that make them interesting.'' This oft quoted quip of Sir Charles Frank speaks to the heart of structural alloys. Indeed, the extent to which the collective effects of defects can be manipulated and controlled determines the combination of structural materials properties that underpins modern energy and transportation technologies. Furthermore, the bounds on performance of current structural materials generally result from limitations in our understanding of defects, rather than insurmountable physical principles. I will describe research in the Center for Defect PhysicsfootnotetextThe CDP is an Energy Frontier Research Center (EFRC), DOE Office of Basic Energy Sciences. in three thrust areas: *Fundamental Physics of Defect Formation and Evolution during Irradiation *Fundamental Physics of Defect Interactions during Deformation *Quantum Theory of Defects and Interactions Specifically, I will described ongoing and planned research that is based on the realization that we are on the verge of a new era of ``quantitative measurement'' and ``direct quantum simulation'' of defects and their interactions enabled by major national facilities (APS, SNS, and LCLS) and the PFlop/s computing (NCCS and NERSC).

  13. Loss Factor of Tapered Structures for Short Bunches

    Energy Technology Data Exchange (ETDEWEB)

    Blednykh, A.

    2011-03-28

    Using the electromagnetic simulation code ECHO, we have found a simple phenomenological formula that accurately describes the loss factor for short bunches traversing an axisymmetric tapered collimator. In this paper, we consider tapered collimators with rectangular cross-section and use the GdfidL code to calculate the loss factor dependence on the geometric parameters for short bunches. The results for both axisymmetric and rectangular collimators are discussed. The behaviour of the impedance of tapered structures for very short bunches in the optical regime has been determined in refs. [10,11]. Here, for the loss factors for two particular geometries, we have studied the departure from the optical regime behaviour as bunch length is increased. In both cases, the ratio of the loss factor for the tapered collimator to the loss factor in the optical regime is a function only of the scaling parameter {sigma}L/d{sup 2}. The fact that the bunch length a and the taper length L appear as a product is consistent with the recent scaling derived by Stupakov in ref. [12], since there is only a weak dependence on g. One noteworthy fact that is not a priori expected is that only the larger radius or vertical half-aperture d appears. The reduction factor is independent of b. Moreover, it is striking that the specific form involving the arctan given in Eq. (5) holds for both geometries, with only the coefficient {mu} differing by a factor of {approx}2 for flat vs round. This suggests that there may be a useful phenomenological form for more general geometries which may follow from natural extensions of Eq. (5). This possibility is presently being investigated.

  14. Metacognition Assessment Interview: Instrument description and factor structure

    Directory of Open Access Journals (Sweden)

    Giovanni Pellecchia

    2015-12-01

    Full Text Available Objective: Metacognition is a multi-component psychological construct, characterised by the ability to identify and describe one’s own mental states and those of others. Evidence has been found for an association between deficits in metacognitive abilities and poor social functioning, low quality of life, psychopathology, and symptoms in Personality Disorders (PDs. However, to date, there are few psychometrically validated instruments available for assessing the different components of metacognition. A semi-structured interview, the Metacognition Assessment Interview (MAI, has been developed to evaluate different domains of metacognition. In the present study, we investigated the psychometric properties of the MAI in an outpatient clinical sample. Method: The MAI was administered to a clinical population of 306 outpatients attending a private clinical centre. Exploratory factor analysis, confirmatory factor analysis and correlation with instruments assessing alexithymia and interpersonal problems were carried out to examine the dimensionality and validity of the MAI. Result: Explorative and confirmatory factor analyses revealed a good fit for both a two-factor model and a four-factor model of metacognition. The two-factor model yielded two main dimensions, which we named: Self domain, defined as self-reflection, and Other domain, defined as critical distancing from one’s own mental state and that of others. The four-factor solution is composed of four sub-domains: monitoring, integration, differentiation and decentration. Moreover, the MAI showed good convergent validity, with significant correlations with both alexithymia and interpersonal problems. Conclusions: These results confirm that the MAI is a reliable instrument for measuring metacognition and its different sub-domains. In particular, the MAI represents a useful and flexible instrument for the assessment of metacognition impairments in different psychopathologies and it can provide

  15. Analysis of structural response under blast loads using the coupled SPH-FEM approach

    Institute of Scientific and Technical Information of China (English)

    Jun-xiang XU; Xi-la LIU

    2008-01-01

    A numerical model using the coupled smoothed particle hydrodynamics-finite element method(SPH-FEM)approach is presented for analysis of structures under blast loads.The analyses on two numerical cases,one for free field explosive and the other for structural response under blast loads,are performed to model the whole processes from the propagation of the pressure wave to the response of structures.Based on the simulation,it is concluded that this model can be used for reasonably accurte explosive analysis of structures.The resulting information would be valuable for protecting structures under blast loads.

  16. Pore Pressure Under A Gravity Based Structure Under The Influence Of Waves

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Carstensen, Stefan; Madsen, Mikael Thyge

    2017-01-01

    The total wave load on a gravity based foundation for offshore wind turbines is influenced by the pore pressure from beneath the structure. The pore pressure is induced by the wave–structure-seabed interaction. Often the uplift force is included in a simplified way in the design of the gravity ba...... analyses, it was possible to investigate the effect of air content in the pores, which turned out to have an effect on the distribution of the pore pressure.......The total wave load on a gravity based foundation for offshore wind turbines is influenced by the pore pressure from beneath the structure. The pore pressure is induced by the wave–structure-seabed interaction. Often the uplift force is included in a simplified way in the design of the gravity...... based foundation. This leads typically to very conservative designs in order to accommodate the uncertainties in the procedure. The experiments shall lead to better prediction models based on for instance CFD model’s with the direct calculation of pressure variations in the seabed and any erosion...

  17. Feelings about culture scales: development, factor structure, reliability, and validity.

    Science.gov (United States)

    Maffini, Cara S; Wong, Y Joel

    2015-04-01

    Although measures of cultural identity, values, and behavior exist in the multicultural psychological literature, there is currently no measure that explicitly assesses ethnic minority individuals' positive and negative affect toward culture. Therefore, we developed 2 new measures called the Feelings About Culture Scale--Ethnic Culture and Feelings About Culture Scale--Mainstream American Culture and tested their psychometric properties. In 6 studies, we piloted the measures, conducted factor analyses to clarify their factor structure, and examined reliability and validity. The factor structure revealed 2 dimensions reflecting positive and negative affect for each measure. Results provided evidence for convergent, discriminant, criterion-related, and incremental validity as well as the reliability of the scales. The Feelings About Culture Scales are the first known measures to examine both positive and negative affect toward an individual's ethnic culture and mainstream American culture. The focus on affect captures dimensions of psychological experiences that differ from cognitive and behavioral constructs often used to measure cultural orientation. These measures can serve as a valuable contribution to both research and counseling by providing insight into the nuanced affective experiences ethnic minority individuals have toward culture.

  18. Residual strength evaluation of concrete structural components under fatigue loading

    Indian Academy of Sciences (India)

    A Rama Chandra Murthy; G S Palani; Nagesh R Iyer; Smitha Gopinath; B K Raghu Prasad

    2012-02-01

    This paper presents methodologies for residual strength evaluation of concrete structural components using linear elastic and nonlinear fracture mechanics principles. The effect of cohesive forces due to aggregate bridging has been represented mathematically by employing tension softening models. Various tension softening models such as linear, bilinear, trilinear, exponential and power curve have been described with appropriate expressions. These models have been validated by predicting the remaining life of concrete structural components and comparing with the corresponding experimental values available in the literature. It is observed that the predicted remaining life by using power model and modified bi-linear model is in good agreement with the corresponding experimental values. Residual strength has also been predicted using these tension softening models and observed that the predicted residual strength is in good agreement with the corresponding analytical values in the literature. In general, it is observed that the variation of predicted residual moment with the chosen tension softening model follows the similar trend as in the case of remaining life. Linear model predicts large residual moments followed by trilinear, bilinear and power models.

  19. Left temporal lobe structural and functional abnormality underlying auditory hallucinations

    Directory of Open Access Journals (Sweden)

    Kenneth Hugdahl

    2009-05-01

    Full Text Available In this article, we review recent findings from our laboratory that auditory hallucinations in schizophrenia are internally generated speech mis-representations lateralized to the left superior temporal gyrus and sulcus. Such experiences are, moreover, not cognitively suppressed due to enhanced attention to the voices and failure of fronto-parietal executive control functions. An overview of diagnostic questionnaires for scoring of symptoms is presented, together with a review of behavioural, structural and functional MRI data. Functional imaging data have either shown increased or decreased activation depending on whether patients have been presented an external stimulus or not during scanning. Structural imaging data have shown reduction of grey matter density and volume in the same areas in the temporal lobe. The behavioral and neuroimaging findings are moreover hypothesized to be related to glutamate hypofunction in schizophrenia. We propose a model for the understanding of auditory hallucinations that trace the origin of auditory hallucinations to uncontrolled neuronal firing in the speech areas in the left temporal lobe, which is not suppressed by volitional cognitive control processes, due to dysfunctional fronto-parietal executive cortical networks.

  20. Evolutionary principles underlying structure and response dynamics of cellular networks.

    Science.gov (United States)

    Steinacher, Arno; Soyer, Orkun S

    2012-01-01

    The network view in systems biology, in conjunction with the continuing development of experimental technologies, is providing us with the key structural and dynamical features of both cell-wide and pathway-level regulatory, signaling and metabolic systems. These include for example modularity and presence of hub proteins at the structural level and ultrasensitivity and feedback control at the level of dynamics. The uncovering of such features, and the seeming commonality of some of them, makes many systems biologists believe that these could represent design principles that underpin cellular systems across organisms. Here, we argue that such claims on any observed feature requires an understanding of how it has emerged in evolution and how it can shape subsequent evolution. We review recent and past studies that aim to achieve such evolutionary understanding for observed features of cellular networks. We argue that this evolutionary framework could lead to deciphering evolutionary origin and relevance of proposed design principles, thereby allowing to predict their presence or absence in an organism based on its environment and biochemistry and their effect on its future evolution.

  1. Analytical Solution for Stress Field and Intensity Factor in CSTBD under Mixed Mode Conditions

    Directory of Open Access Journals (Sweden)

    Najaf Ali Ghavidel

    2014-06-01

    Full Text Available Considering the fact that rocks fail faster under tensile stress, rock tensile strength is of greatimportance in applications such as blasting, rock fragmentation, slope stability, hydraulic fracturing,caprock integrity, and geothermal energy extraction. There are two direct and indirect methods tomeasure tensile strength. Since direct methods always encompass difficulties in test setup, indirectmethods, specifically the Brazilian test, have often been employed for tensile strength measurement.Tensile failure is technically attributed to crack propagation in rock. Fracture mechanics hassignificant potential for the determination of crack behaviour as well as propagation pattern. To applyBrazilian tests, cracked disc geometry has been suggested by the International Society for RockMechanics ISRM. Accordingly, a comprehensive study is necessary to evaluate stress field and stressintensity factor (SIF around the crack in the centre of the specimen. In this paper, superpositionprinciple is employed to solve the problem of cracked straight-through Brazilian disc (CSTBD, usingtwo methods of dislocation and complex stress function. Stress field and SIF in the vicinity of thecrack tip are then calculated. With the proposed method, the magnitude of critical load for crackinitiation in structures can be predicted. This method is valid for any crack of any arbitrary length andangle. In addition, numerical modelling has been carried out for the Brazilian disc. Finally, theanalytical solution has been compared with numerical modelling results showing the same outcomefor both methods.

  2. Pentachlorophenol (PCP) degradation microorganism community structure under microaeration condition

    Institute of Scientific and Technical Information of China (English)

    Chen Yuancai; Hao Yuan; Fu Shiyu; Zhan Huaiyu

    2007-01-01

    The comparison of pentachlorophenol (PCP)degradation was conducted under micro-aeration and anaerobic condition with three series of batch experiment,results of which indicated that during micro-aeration condition co-immobilized of anaerobic granular sludge and isolated aerobic bacterial species could enhance the efficiency of PCP reduction through the synergism of aerobes and anaerobes reductive dechlorination and exchange of metabolites within the co-immobilized granular sludge.While during anaerobic condition,there was no great difference in the three series.The specific activities experiment further confirmed that strict anaerobes were not affected over the presence of micro aeration environment.Microorganism community construction of co-immobilized anaerobic granular sludge and the mixed isolated aerobic community was also deduced.By the efficient cooperation of aerobes and anaerobes,the high efficiency removal rate of PCP was implemented.

  3. Proceedings of the 1. international workshop on performance protection, and strengthening of structures under extreme loading

    Energy Technology Data Exchange (ETDEWEB)

    Banthia, N.; Mindess, S. [British Columbia Univ., Vancouver, BC (Canada); Fujikake, K. [National Defense Academy, Hashirimizu (Japan)] (eds.)

    2007-07-01

    This workshop was held to bring together experts from diverse engineering backgrounds to discuss recent developments in the performance, protection, and strengthening of structures exposed to extreme events. The aim of the workshop was to create a multidisciplinary forum to enhance the understanding of complex issues related to structures under extreme loading. Papers presented at the workshop examined designs and collapse mechanisms, and explored cost-effective strengthening and protection measures. Innovative and effective strategies related to civil engineering and project management were discussed along with new technologies and construction materials. New approaches to computer modelling were also discussed. The structural performance of measuring tools were also reviewed. The workshop was divided into the following 4 themes: (1) structures under impact and shock; (2) structures under blast and fire; (3) structures under seismic loads and vibrations; and (4) structural performance and strengthening. The workshop featured 108 presentations, of which 5 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  4. Phase Transitions in Sampling Algorithms and the Underlying Random Structures

    Science.gov (United States)

    Randall, Dana

    Sampling algorithms based on Markov chains arise in many areas of computing, engineering and science. The idea is to perform a random walk among the elements of a large state space so that samples chosen from the stationary distribution are useful for the application. In order to get reliable results, we require the chain to be rapidly mixing, or quickly converging to equilibrium. For example, to sample independent sets in a given graph G, the so-called hard-core lattice gas model, we can start at any independent set and repeatedly add or remove a single vertex (if allowed). By defining the transition probabilities of these moves appropriately, we can ensure that the chain will converge to a use- ful distribution over the state space Ω. For instance, the Gibbs (or Boltzmann) distribution, parameterized by Λ> 0, is defined so that p(Λ) = π(I) = Λ|I| /Z, where Z = sum_{J in Ω} Λ^{|J|} is the normalizing constant known as the partition function. An interesting phenomenon occurs as Λ is varied. For small values of Λ, local Markov chains converge quickly to stationarity, while for large values, they are prohibitively slow. To see why, imagine the underlying graph G is a region of the Cartesian lattice. Large independent sets will dominate the stationary distribution π when Λ is sufficiently large, and yet it will take a very long time to move from an independent set lying mostly on the odd sublattice to one that is mostly even. This phenomenon is well known in the statistical physics community, and characterizes by a phase transition in the underlying model.

  5. UCLA Loneliness Scale (Version 3): reliability, validity, and factor structure.

    Science.gov (United States)

    Russell, D W

    1996-02-01

    In this article I evaluated the psychometric properties of the UCLA Loneliness Scale (Version 3). Using data from prior studies of college students, nurses, teachers, and the elderly, analyses of the reliability, validity, and factor structure of this new version of the UCLA Loneliness Scale were conducted. Results indicated that the measure was highly reliable, both in terms of internal consistency (coefficient alpha ranging from .89 to .94) and test-retest reliability over a 1-year period (r = .73). Convergent validity for the scale was indicated by significant correlations with other measures of loneliness. Construct validity was supported by significant relations with measures of the adequacy of the individual's interpersonal relationships, and by correlations between loneliness and measures of health and well-being. Confirmatory factor analyses indicated that a model incorporating a global bipolar loneliness factor along with two method factor reflecting direction of item wording provided a very good fit to the data across samples. Implications of these results for future measurement research on loneliness are discussed.

  6. Structural attributes of stand overstory and light under the canopy

    Directory of Open Access Journals (Sweden)

    Alice Angelini

    2015-02-01

    Full Text Available  This paper reviews the literature relating to the relationship between light availability in the understory and the main qualitative and quantitative attributes of stand overstory usually considered in forest management and planning (species composition, density, tree sizes, etc. as well as their changes as consequences of harvesting. The paper is divided in two sections: the first one reviews studies which investigated the influence of species composition on understory light conditions; the second part examines research on the relationships among stand parameters determined from dendrometric field data and the radiation on understory layer. The objective was to highlight which are the most significant stand traits and management features to build more practical models for predicting light regimes in any forest stand and, in more general terms, to support forest managers in planning and designing silvicultural treatments that retain structure in different way in order to meet different objectives.

  7. Soil compaction and structural morphology under tractor wheelings

    Science.gov (United States)

    Shanahan, Peter; Quinton, John; Binley, Andrew; Silgram, Martyn

    2010-05-01

    Compaction of cultivated soils is a major problem for agriculture in terms of yield decline and sustainable soil resource management. Tramline wheelings exacerbate runoff and increase erosion from arable land. The UK Department for Environment, Food and Rural Affairs (Defra) LINK Project - a joint venture between agri-business, land managers and research groups - is currently evaluating a number of methods for alleviating compaction in tractor wheelings across a range of soil types in England. Using innovative applications of agri-geophysics (e.g. ground penetrating radar, electrical resistivity, acoustics and x-ray tomography), this current project aims to determine relationships between properties derived from geophysical methods (e.g. soil moisture, porosity), soil compaction and structural morphology. Such relationships are important for a clearer understanding of hydrological and biogeochemical processes in compacted soils, to address land management practices and develop cost-effective mitigation measures. Our poster will present some early results of this study.

  8. Optimal Design of Composite Structures Under Manufacturing Constraints

    DEFF Research Database (Denmark)

    Marmaras, Konstantinos

    mixed integer 0–1 programming problems. The manufacturing constraints have been treated by developing explicit models with favorable properties. In this thesis we have developed and implemented special purpose global optimization methods and heuristic techniques for solving this class of problems......This thesis considers discrete multi material and thickness optimization of laminated composite structures including local failure criteria and manufacturing constraints. Our models closely follow an immediate extension of the Discrete Material Optimization scheme, which allows simultaneous....... The continuous relaxation of the mixed integer programming problems is being solved by an implementation of a primal–dual interior point method for nonlinear programming that updates the barrier parameter adaptively. The method is chosen for its excellent convergence properties and the ability of the method...

  9. Optimal Design of Composite Structures Under Manufacturing Constraints

    DEFF Research Database (Denmark)

    Marmaras, Konstantinos

    mixed integer 0–1 programming problems. The manufacturing constraints have been treated by developing explicit models with favorable properties. In this thesis we have developed and implemented special purpose global optimization methods and heuristic techniques for solving this class of problems....... The continuous relaxation of the mixed integer programming problems is being solved by an implementation of a primal–dual interior point method for nonlinear programming that updates the barrier parameter adaptively. The method is chosen for its excellent convergence properties and the ability of the method...... determination of the appropriate laminate thickness and the material choice in the structure. The optimal design problems that arise are stated as nonconvex mixed integer programming problems. We resort to different reformulation techniques to state the optimization problems as either linear or nonlinear convex...

  10. Bacterial sigma factors: a historical, structural, and genomic perspective.

    Science.gov (United States)

    Feklístov, Andrey; Sharon, Brian D; Darst, Seth A; Gross, Carol A

    2014-01-01

    Transcription initiation is the crucial focal point of gene expression in prokaryotes. The key players in this process, sigma factors (σs), associate with the catalytic core RNA polymerase to guide it through the essential steps of initiation: promoter recognition and opening, and synthesis of the first few nucleotides of the transcript. Here we recount the key advances in σ biology, from their discovery 45 years ago to the most recent progress in understanding their structure and function at the atomic level. Recent data provide important structural insights into the mechanisms whereby σs initiate promoter opening. We discuss both the housekeeping σs, which govern transcription of the majority of cellular genes, and the alternative σs, which direct RNA polymerase to specialized operons in response to environmental and physiological cues. The review concludes with a genome-scale view of the extracytoplasmic function σs, the most abundant group of alternative σs.

  11. Crystal Structure of the Pseudomonas aeruginosa Virulence Factor Regulator

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, Timothy J.; Worzalla, Gregory A.; Ginster, Aaron M.; Forest, Katrina T. (UW)

    2012-09-07

    Virulence factor regulator (Vfr) enhances Pseudomonas aeruginosa pathogenicity through its role as a global transcriptional regulator. The crystal structure of Vfr shows that it is a winged-helix DNA-binding protein like its homologue cyclic AMP receptor protein (CRP). In addition to an expected primary cyclic AMP-binding site, a second ligand-binding site is nestled between the N-terminal domain and the C-terminal helix-turn-helix domain. Unlike CRP, Vfr is a symmetric dimer in the absence of DNA. Removal of seven disordered N-terminal residues of Vfr prvents the growth of P. aeruginosa.

  12. Partial structure factors in star polymer/colloid mixtures

    CERN Document Server

    Stellbrink, J; Richter, D; Moussaid, A; Schofield, A B; Poon, W C K; Pusey, P N; Lindner, P; Dzubiella, J; Likos, C N; Löwen, H

    2002-01-01

    Addition of polymer to colloidal suspensions induces an attractive part to the colloid pair potential, which is of purely entropic origin (''depletion interaction''). We investigated the influence of polymer branching on depletion forces by studying mixtures of hard sphere colloids and star polymers with increasing arm number f=2-32, but constant R sub g approx 500 A. We found a pronounced effect of branching on the position of the gas/liquid demixing transition. Using small angle neutron scattering (SANS) we were able to measure partial structure factors in star polymer/colloid mixtures. The relative distance to the demixing transition is reflected in our scattering data. (orig.)

  13. Dynamical Structure Factors of quasi-one-dimensional antiferromagnets

    Science.gov (United States)

    Hagemans, Rob; Caux, Jean-Sébastien; Maillet, Jean Michel

    2007-03-01

    For a long time it has been impossible to accurately calculate the dynamical structure factors (spin-spin correlators as a function of momentum and energy) of quasi-one-dimensional antiferromagnets. For integrable Heisenberg chains, the recently developed ABACUS method (a first-principles computational approach based on the Bethe Ansatz) now yields highly accurate (over 99% of the sum rule) results for the DSF for finite chains, allowing for a very precise description of neutron-scattering data over the full momentum and energy range. We show remarkable agreement between results obtained with ABACUS and experiment.

  14. Variable structure motifs for transcription factor binding sites.

    Science.gov (United States)

    Reid, John E; Evans, Kenneth J; Dyer, Nigel; Wernisch, Lorenz; Ott, Sascha

    2010-01-14

    Classically, models of DNA-transcription factor binding sites (TFBSs) have been based on relatively few known instances and have treated them as sites of fixed length using position weight matrices (PWMs). Various extensions to this model have been proposed, most of which take account of dependencies between the bases in the binding sites. However, some transcription factors are known to exhibit some flexibility and bind to DNA in more than one possible physical configuration. In some cases this variation is known to affect the function of binding sites. With the increasing volume of ChIP-seq data available it is now possible to investigate models that incorporate this flexibility. Previous work on variable length models has been constrained by: a focus on specific zinc finger proteins in yeast using restrictive models; a reliance on hand-crafted models for just one transcription factor at a time; and a lack of evaluation on realistically sized data sets. We re-analysed binding sites from the TRANSFAC database and found motivating examples where our new variable length model provides a better fit. We analysed several ChIP-seq data sets with a novel motif search algorithm and compared the results to one of the best standard PWM finders and a recently developed alternative method for finding motifs of variable structure. All the methods performed comparably in held-out cross validation tests. Known motifs of variable structure were recovered for p53, Stat5a and Stat5b. In addition our method recovered a novel generalised version of an existing PWM for Sp1 that allows for variable length binding. This motif improved classification performance. We have presented a new gapped PWM model for variable length DNA binding sites that is not too restrictive nor over-parameterised. Our comparison with existing tools shows that on average it does not have better predictive accuracy than existing methods. However, it does provide more interpretable models of motifs of variable

  15. Variable structure motifs for transcription factor binding sites

    Directory of Open Access Journals (Sweden)

    Wernisch Lorenz

    2010-01-01

    Full Text Available Abstract Background Classically, models of DNA-transcription factor binding sites (TFBSs have been based on relatively few known instances and have treated them as sites of fixed length using position weight matrices (PWMs. Various extensions to this model have been proposed, most of which take account of dependencies between the bases in the binding sites. However, some transcription factors are known to exhibit some flexibility and bind to DNA in more than one possible physical configuration. In some cases this variation is known to affect the function of binding sites. With the increasing volume of ChIP-seq data available it is now possible to investigate models that incorporate this flexibility. Previous work on variable length models has been constrained by: a focus on specific zinc finger proteins in yeast using restrictive models; a reliance on hand-crafted models for just one transcription factor at a time; and a lack of evaluation on realistically sized data sets. Results We re-analysed binding sites from the TRANSFAC database and found motivating examples where our new variable length model provides a better fit. We analysed several ChIP-seq data sets with a novel motif search algorithm and compared the results to one of the best standard PWM finders and a recently developed alternative method for finding motifs of variable structure. All the methods performed comparably in held-out cross validation tests. Known motifs of variable structure were recovered for p53, Stat5a and Stat5b. In addition our method recovered a novel generalised version of an existing PWM for Sp1 that allows for variable length binding. This motif improved classification performance. Conclusions We have presented a new gapped PWM model for variable length DNA binding sites that is not too restrictive nor over-parameterised. Our comparison with existing tools shows that on average it does not have better predictive accuracy than existing methods. However, it does

  16. Functional Factor Analysis In Sesame Under Water - Limiting Stress: New Concept On An Old Method

    Directory of Open Access Journals (Sweden)

    Mansouri Sadollah

    2014-12-01

    Full Text Available Multivariate statistical analysis, through their ability to extract hidden relationship between various traits, has a wide application in breeding programs. Having physiological concept on the multivariate analysis, factor analysis was used to extract differential relationships between different components involving in assimilate partitioning in sesame under regular irrigation regime and limited irrigation. The analysis revealed that under regular irrigation regime, the stored and/or currently produced assimilates are allocated to the filling seeds. However, incidence of water shortage in the beginning of flowering time make shifts in assimilate partitioning from formation of new seeds or capsules to the not-matured pre-formed seeds, which results in seeds with more nutrient storage. This indicates the requirement for change in breeding strategies under sub-optimal condition. The possible common language between factor concept in multivariate analysis, QTLs in genetics, and transcription factors in molecular biology is indicated.

  17. 低碳经济目标下一次能源消费结构影响因素分析%Analysis of the Influence Factors of the Primary Energy Consumption Structure under the Target of Low-Carbon Economy

    Institute of Scientific and Technical Information of China (English)

    范德成; 王韶华; 张伟

    2012-01-01

    低碳经济实现的重点在于能源结构的优化。本文通过文献回顾的方式提炼了一次能源消费结构的主要影响因素,并通过路径分析测算各影响因素对能源消费结构的总影响、直接影响和间接影响,明确了影响机理。其中,能耗量约束和GDP增长对能源消费结构的优化起直接推动作用;但在碳强度和能耗强度保持不变的条件下,碳排放约束和能耗量约束总影响上对能源消费结构的优化起抑制作用。在此基础上,通过岭回归方法消除各因素的多重共线性,构建了一次能源消费结构的预测模型,并据此得出,为实现2020年低碳经济目标,煤炭消费比重应降至65.99%~66.72%,在增加GDP的同时,降低能源消耗和碳排放。%In contrast to high-carbon economy, low-carbon economy is characterized by low consumption, low emissions and low pollution, so it is the most sustainable economic development model, the essence of which is changing energy use, improving energy efficiency and optimizing the energy structure through technological progress and institutional innovation. Optimization of energy structure is the key to low-carbon economy. In this paper, we summarized the main influence factors of primary energy consumption structure by reviewing the document records. The factors include energy consumption constraint, carbon emissions constraint, total population, industrial structure and GDP. At the same time, we calculated the total, direct as well as indirect impacts of each influence factor on the energy consumption structure by path analysis and then got the influence mechanism. The results indicate that energy consumption constraint and GDP growth are the main driving factors for the optimization of energy structure. However, with the extensive economic growth, low-level production technology, strong dependence on energy consumption, the carbon emissions constraint and GDP growth have inhibition effect on the

  18. Factor Structure of the Student-Teacher Relationship Scale for Norwegian School-Age Children Explored with Confirmatory Factor Analysis

    Science.gov (United States)

    Drugli, May Britt; Hjemdal, Odin

    2013-01-01

    The validity of the Student-Teacher Relationship Scale (STRS) was examined in a national sample of 863 Norwegian schoolchildren in grades 1-7 (aged 6-13). The original factor structure of the STRS was tested by confirmatory factor analysis (CFA). The CFA results did not support the original three-factor structure of the STRS. Subsequent CFA of the…

  19. Resonances in nonlinear structure vibrations under multifrequency excitations

    Energy Technology Data Exchange (ETDEWEB)

    El-Bassiouny, A F [Faculty of Science, Mathematics Department, Benha University, Benha 1358 (Egypt); El-Latif, G M Abd [Faculty of Science, Mathematics Department, Sohag University, Sohag (Egypt)

    2006-10-15

    The response of a single-degree-of-freedom system with quadratic, cubic and quartic nonlinearities subjected to a sinusoidal excitation that involves multiple frequencies is considered. The method of multiple scales is used to construct a first order uniform expansion yielding two first-order nonlinear ordinary differential equations that are derived for the evolution of the amplitude and phase. These oscillations involve a subharmonic oscillation of order one-fourth and superharmonic oscillation of order two. Steady state responses and their stability are computed for selected values of the system parameters. The effects of these (quadratic, cubic, and quartic) nonlinearities on these oscillations are specifically investigated. With this study, it has been verified that the qualitative effects of these nonlinearities are different. Regions of hardening (softening) behaviour of the system exist for the case of subharmonic resonance. The response curve is not affected by decreasing the damping factor for the case of superharmonic resonance. It is shown that the response curve contracts or expands as the parameters vary. The multivalued region increases or decreases when some parameters vary.

  20. Dynamics of the Human Structural Connectome Underlying Working Memory Training

    Science.gov (United States)

    Metzler-Baddeley, Claudia; Foley, Sonya; Jones, Derek K.

    2016-01-01

    Brain region-specific changes have been demonstrated with a variety of cognitive training interventions. The effect of cognitive training on brain subnetworks in humans, however, remains largely unknown, with studies limited to functional networks. Here, we used a well-established working memory training program and state-of-the art neuroimaging methods in 40 healthy adults (21 females, mean age 26.5 years). Near and far-transfer training effects were assessed using computerized working memory and executive function tasks. Adaptive working memory training led to improvement on (non)trained working memory tasks and generalization to tasks of reasoning and inhibition. Graph theoretical analysis of the structural (white matter) network connectivity (“connectome”) revealed increased global integration within a frontoparietal attention network following adaptive working memory training compared with the nonadaptive group. Furthermore, the impact on the outcome of graph theoretical analyses of different white matter metrics to infer “connection strength” was evaluated. Increased efficiency of the frontoparietal network was best captured when using connection strengths derived from MR metrics that are thought to be more sensitive to differences in myelination (putatively indexed by the [quantitative] longitudinal relaxation rate, R1) than previously used diffusion MRI metrics (fractional anisotropy or fiber-tracking recovered streamlines). Our findings emphasize the critical role of specific microstructural markers in providing important hints toward the mechanisms underpinning training-induced plasticity that may drive working memory improvement in clinical populations. SIGNIFICANCE STATEMENT This is the first study to explore training-induced changes in the structural connectome using a well-controlled design to examine cognitive training with up-to-date neuroimaging methods. We found changes in global integration based on white matter connectivity within a

  1. Counterparty risk analysis using Merton's structural model under Solvency II

    Directory of Open Access Journals (Sweden)

    Luis Otero González

    2014-12-01

    Full Text Available The new solvency regulation in the European insurance sector, denominated Solvency II, will completely transform the system of capital requirements estimation. Recently it has introduced the latest quantitative impact study (QIS5, which provides the calculation method in the internal model for the determination of capital requirements. The aim of this paper is to analyze the adequacy of the calibration of the counterparty credit risk by the models proposed in recent quantitative impact reports (fourth and fifth. To do this we compare capital requirements obtained by the two alternatives, against which that results from applying a simulation model based on the structural approach. The results shows that the use of probabilities based on the methodology of Merton, which can be used in an internal model, compared to those based on ratings (standard model result in substantially higher capital requirements. In addition, the model proposed in QIS4 based on Vasicek distribution is not appropriate when the number of counterparties is reduced, a common situation in the European insurance sector. Moreover, the new proposal (QIS5 or Ter Berg model is more versatile and suitable than its predecessor but requires further research in order to improve the calibration hypothesis and, thus, to better approximate estimates to the risk actually assumed.

  2. Structural modification of bacterial cellulose fibrils under ultrasonic irradiation.

    Science.gov (United States)

    Paximada, Paraskevi; Dimitrakopoulou, Eleni Alkmini; Tsouko, Erminda; Koutinas, Apostolos A; Fasseas, C; Mandala, Ioanna G

    2016-10-05

    Ιn the present study we investigated ultrasounds as a pretreatment process for bacterial cellulose (BC) aqueous suspensions. BC suspensions (0.1-1% wt) subjected to an ultrasonic treatment for different time intervals. Untreated BC presented an extensively entangled fibril network. When a sonication time of 1min was applied BC fibrils appeared less bundled and dropped in width from 110nm to 60nm. For a longer treatment (3-5min) the width of the fibrils increased again to 100nm attributed to an entanglement of their structure. The water holding capacity (WHC) and ζ-potnential of the suspensions was proportional to the sonication time. Their viscosity and stability were also affected; an increase could be seen at short treatments, while a decrease was obvious at longer ones. Concluding, a long ultrasonic irradiation led to similar BC characteristics as the untreated, but a short treatment may be a pre-handling method for improving BC properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Statistical structure of intrinsic climate variability under global warming

    Science.gov (United States)

    Zhu, Xiuhua; Bye, John; Fraedrich, Klaus

    2017-04-01

    Climate variability is often studied in terms of fluctuations with respect to the mean state, whereas the dependence between the mean and variability is rarely discussed. We propose a new climate metric to measure the relationship between means and standard deviations of annual surface temperature computed over non-overlapping 100-year segments. This metric is analyzed based on equilibrium simulations of the Max Planck Institute-Earth System Model (MPI-ESM): the last millennium climate (800-1799), the future climate projection following the A1B scenario (2100-2199), and the 3100-year unforced control simulation. A linear relationship is globally observed in the control simulation and thus termed intrinsic climate variability, which is most pronounced in the tropical region with negative regression slopes over the Pacific warm pool and positive slopes in the eastern tropical Pacific. It relates to asymmetric changes in temperature extremes and associates fluctuating climate means with increase or decrease in intensity and occurrence of both El Niño and La Niña events. In the future scenario period, the linear regression slopes largely retain their spatial structure with appreciable changes in intensity and geographical locations. Since intrinsic climate variability describes the internal rhythm of the climate system, it may serve as guidance for interpreting climate variability and climate change signals in the past and the future.

  4. Examining Factor Structure of the Chinese Version of the PIRLS 2011 Home Questionnaire

    Directory of Open Access Journals (Sweden)

    Wai Ming Cheung

    2016-01-01

    Full Text Available The home questionnaire of the Progress in International Reading Literacy Study (PIRLS-HQ 2011 was designed to gather information from parents or primary caregivers of fourth-grade pupils on their reading literacy development related to aspects of pupils’ home lives across countries/districts. The questionnaire was translated into different languages for international comparison and research purposes. This study aims to assess the psychometric properties of the Chinese version of the PIRLS 2011 home questionnaire (PIRLS-HQCV 2011 and identify the underlying factor structure using exploratory factor analysis (EFA and confirmatory factor analysis (CFA among Chinese fourth-grade pupils in Hong Kong. A 7-factor structure model has been identified by EFA and confirmed to resemble much to the original PIRLS structure by CFA. Additional conceptually important domains have been identified which add further insights into the inconclusive results in the literature regarding the relationship between home factors and reading achievement. Implications for further studies are discussed.

  5. A Reexamination of the Factor Structure of the Center for Epidemiologic Studies Depression Scale: Is a One-Factor Model Plausible?

    Science.gov (United States)

    Edwards, Michael C.; Cheavens, Jennifer S.; Heiy, Jane E.; Cukrowicz, Kelly C.

    2010-01-01

    The Center for Epidemiologic Studies Depression Scale (CES-D) is one of the most widely used measures of depressive symptoms in research today. The original psychometric work in support of the CES-D (Radloff, 1977) described a 4-factor model underlying the 20 items on the scale. Despite a long history of evidence supporting this structure,…

  6. Parallel structural evolution of auxin response factors in the angiosperms.

    Science.gov (United States)

    Finet, Cédric; Fourquin, Chloé; Vinauger, Marion; Berne-Dedieu, Annick; Chambrier, Pierre; Paindavoine, Sandrine; Scutt, Charles P

    2010-09-01

    Here we analyze the structural evolution of the paralogous transcription factors ETTIN (ETT/ARF3) and AUXIN RESPONSE FACTOR 4 (ARF4), which control the development of floral organs and leaves in the model angiosperm Arabidopsis. ETT is truncated at its C terminus, and consequently lacks two regulatory domains present in most other ARFs, including ARF4. Our analysis indicates ETT and ARF4 to have been generated by the duplication of a non-truncated ARF gene prior to the radiation of the extant angiosperms. We furthermore show that either ETT or ARF4 orthologs have become modified to encode truncated ARF proteins, lacking C-terminal regulatory domains, in representatives of three groups that separated early in angiosperm evolution: Amborellales, Nymphaeales and the remaining angiosperm clade. Interestingly, the production of truncated ARF4 transcripts in Amborellales occurs through an alternative splicing mechanism, rather than through a permanent truncation, as in the other groups studied. To gain insight into the potential functional significance of truncations to ETT and ARF4, we tested the capacity of native, truncated and chimeric coding sequences of these genes to restore a wild-type phenotype to Arabidopsis ett mutants. We discuss the results of this analysis in the context of the structural evolution of ARF genes in the angiosperms. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

  7. DSM-5 posttraumatic stress disorder: factor structure and rates of diagnosis.

    Science.gov (United States)

    Gentes, Emily L; Dennis, Paul A; Kimbrel, Nathan A; Rissling, Michelle B; Beckham, Jean C; Calhoun, Patrick S

    2014-12-01

    Posttraumatic stress disorder (PTSD) is a significant problem among Iraq/Afghanistan-era veterans. To date, however, there has been only limited research on how the recent changes in DSM-5 influence the prevalence and factor structure of PTSD. To address this key issue, the present research used a modified version of a gold-standard clinical interview to assess PTSD among a large sample of Iraq/Afghanistan-era veterans (N = 414). Thirty-seven percent of the sample met DSM-5 criteria for PTSD compared to a rate of 38% when DSM-IV diagnostic criteria were used. Differences in rates of diagnosis between DSM-IV and DSM-5 were primarily attributable to changes to Criterion A and the separation of the "avoidance" and "numbing" symptoms into separate clusters. Confirmatory factor analysis (CFA) was used to compare the fit of the previous 3-factor DSM-IV model of PTSD to the 4-factor model specified in DSM-5, a 4-factor "dysphoria" model, and a 5-factor model. CFA demonstrated that the 5-factor model (re-experiencing, active avoidance, emotional numbing, dysphoric arousal, anxious arousal) provided the best overall fit to the data, although substantial support was also found for the 4-factor DSM-5 model. Low factor loadings were noted for two of the symptoms in the DSM-5 model (psychogenic amnesia and reckless/self-destructive behavior), raising questions regarding the adequacy of fit between these symptoms and the other core features of PTSD. Overall, findings suggest the DSM-5 model of PTSD is an improvement over the previous DSM-IV model of PTSD, but still may not represent the true underlying factor structure of PTSD.

  8. [Factors influencing the spatial variability in soil respiration under different land use regimes].

    Science.gov (United States)

    Chen, Shu-Tao; Liu, Qiao-Hui; Hu, Zheng-Hua; Liu, Yan; Ren, Jing-Quan; Xie, Wei

    2013-03-01

    In order to investigate the factors influencing the spatial variability in soil respiration under different land use regimes, field experiments were performed. Soil respiration and relevant environment, vegetation and soil factors were measured. The spatial variability in soil respiration and the relationship between soil respiration and these measured factors were investigated. Results indicated that land use regimes had significant effects on soil respiration. Soil respiration varied significantly (P DBH) of trees can be explained by a natural logarithmic function. A model composed of soil organic carbon (C, %), available phosphorous (AP, g x kg(-1)) and diameter at breast height (DBH, cm) explained 92.8% spatial variability in soil respiration for forest ecosystems.

  9. The influence of the crust layer on RPV structural failure under severe accident condition

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Jianfeng, E-mail: jianfeng-mao@163.com [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Li, Xiangqing [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Bao, Shiyi [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Luo, Lijia [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Gao, Zengliang [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China)

    2017-05-15

    Highlights: • The crust layer greatly affects the RPV structural behavior. • The RPV failure is investigated in depth under severe accident. • The creep and plastic damage mainly contribute to RPV failure. • An elastic core in RPV wall is essential for ensuring RPV integrity. • The multiaxial state of stress accelerates the total damage evolution. - Abstract: The so called ‘in-vessel retention (IVR)’ is regarded as a severe accident (SA) mitigation strategy, which is widely used in most of advanced nuclear power plants. The effectiveness of IVR strategy is to employ the external water flooding to cool the reactor pressure vessel (RPV). The RPV integrity has to be maintained within a required period during the IVR period. The degraded melting core is assumed to be arrested in the lower head (LH) to form the melting pool that is bounded by upper, side and lower crusts. Consequently, the existence of the crust layer greatly affects the RPV structural behavior as well as failure process. In order to disclose this influence caused by the crust layer, a detailed investigation is conducted by using numerical simulation on the two RPVs with and without crust layer respectively. Taking the RPV without crust layer as a basis for the comparison, the present study assesses the likelihood and potential failure location, time and mode of the LH under the loadings of the critical heat flux (CHF) and slight internal pressure. Due to the high temperature melt on the inside and nucleate boiling on the outside, the RPV integrity is found to be compromised by melt-through, creep, elasticity, plasticity as well as thermal expansion. Through in-depth investigation, it is found that the creep and plasticity are of vital importance to the final structural failure, and the introduction of crust layer results in a significant change on field parameters in terms of temperature, deformation, stress(strain), triaxiality factor and total damage.

  10. Influencing factors on elastic-plastic deformation of multi-layered surfaces under sliding contact

    Institute of Scientific and Technical Information of China (English)

    YAN Li; PAN Xin-xiang; XU Jiu-jun; CHENG Dong

    2004-01-01

    Stress distribution in the gradient multi-layered surface under a sliding contact was investigated using finite element method(FEM). The main structure parameters of layered surface discussed are total layer thickness,layer number and elastic modulus ratio of layer to the substrate. A model of multi-layered surface contact with rough slider was studied. The effect of the surface structure parameters on the elastic-plastic deformation was analyzed.

  11. Pathophysiological domains underlying the metabolic syndrome: an alternative factor analytic strategy.

    Science.gov (United States)

    Peeters, Carel F W; Dziura, James; van Wesel, Floryt

    2014-10-01

    Factor analysis (FA) has become part and parcel in metabolic syndrome (MBS) research. Both exploration- and confirmation-driven factor analyzes are rampant. However, factor analytic results on MBS differ widely. A situation that is at least in part attributable to misapplication of FA. Here, our purpose was (i) to review factor analytic efforts in the study of MBS with emphasis on misusage of the FA model and (ii) to propose an alternative factor analytic strategy. The proposed factor analytic strategy consists of four steps and confronts weaknesses in application of the FA model. At its heart lies the explicit separation of dimensionality and pattern selection and the direct evaluation of competing inequality-constrained loading patterns. A high-profile MBS data set with anthropometric measurements on overweight children and adolescents is reanalyzed using this strategy. The reanalysis implied a more parsimonious constellation of pathophysiological domains underlying phenotypic expressions of MBS than the original analysis (and many other analyses). The results emphasize correlated factors of impaired glucose metabolism and impaired lipid metabolism. Pathophysiological domains underlying phenotypic expressions of MBS included in the analysis are driven by multiple interrelated metabolic impairments. These findings indirectly point to the possible existence of a multifactorial etiology. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. A METHOD FOR TOPOLOGICAL OPTIMIZATION OF STRUCTURES WITH DISCRETE VARIABLES UNDER DYNAMIC STRESS AND DISPLACEMENT CONSTRAINTS

    Institute of Scientific and Technical Information of China (English)

    石连栓; 孙焕纯; 冯恩民

    2001-01-01

    A method for topological optimization of structures with discrete variables subjected to dynamic stress and displacement constraints is presented. By using the quasistatic method, the structure optimization problem under dynamic stress and displacement constraints is converted into one subjected to static stress and displacement constraints. The comprehensive algorithm for topological optimization of structures with discrete variables is used to find the optimum solution.

  13. A Cyclodissipativity Condition for Power Factor Improvement under Nonsinusoidal Source with Significant Impedance

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2010-01-01

    The main contribution of this paper is an extension of a recent result that reformulates and solves the power factor compensation for nonlinear loads under nonsinusoidal regime in terms of cyclodissipativity. In the aforementioned result the generator was assumed to be ideal, that is, with negligibl

  14. Relative Damage Stress: Dominant Mechanical Factor for the Failure of Soldered Joints under Temperature Cycling

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By temperature normalization of the concept of equivalent damage stress proposed by Lemaitre,a new concept of relative damage stress has been put forward as the dominant mechanical factor for the failure of soldered joints under temperature cycling. Finite element numerical simulation results showed that the highest value of relative damage stress occurred at the high temperaturehold time during temperature cycling history.

  15. Overland flow under rainfall: some aspects related to modelling and conditioning factors.

    NARCIS (Netherlands)

    Lima, de J.L.M.P.

    1989-01-01

    This study concerns the theory and some practical aspects of overland flow under rainfall. Of the conditioning factors and processes which govern the generation of overland flow, the following were studied: depression storage, infiltration, morphology and wind. Special attention was paid to wind-dri

  16. Demographic factors and genetic variation influence population persistence under environmental change.

    Science.gov (United States)

    Willi, Yvonne; Hoffmann, Ary A

    2009-01-01

    Population persistence has been studied in a conservation context to predict the fate of small or declining populations. Persistence models have explored effects on extinction of random demographic and environmental fluctuations, but in the face of directional environmental change they should also integrate factors affecting whether a population can adapt. Here, we examine the population-size dependence of demographic and genetic factors and their likely contributions to extinction time under scenarios of environmental change. Parameter estimates were derived from experimental populations of the rainforest species, Drosophila birchii, held in the lab for 10 generations at census sizes of 20, 100 and 1000, and later exposed to five generations of heat-knockdown selection. Under a model of directional change in the thermal environment, rapid extinction of populations of size 20 was caused by a combination of low growth rate (r) and high stochasticity in r. Populations of 100 had significantly higher reproductive output, lower stochasticity in r and more additive genetic variance (V(A)) than populations of 20, but they were predicted to persist less well than the largest size class. Even populations of 1000 persisted only a few hundred generations under realistic estimates of environmental change because of low V(A) for heat-knockdown resistance. The experimental results document population-size dependence of demographic and adaptability factors. The simulations illustrate a threshold influence of demographic factors on population persistence, while genetic variance has a more elastic impact on persistence under environmental change.

  17. Nucleon Structure and Hyperon Form Factors from Lattice QCD.

    Energy Technology Data Exchange (ETDEWEB)

    Lin,H.W.

    2007-06-11

    In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5), consistent with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(2G), consistent with the Adelaide-JLab Collaboration's result. The hyperon {Sigma} and {Xi} axial coupling constants are also performed for the first time in a lattice calculation, g{sub {Sigma}{Sigma}} = 0.441(14) and g{sub {Xi}{Xi}} = -0.277(11).

  18. Nucleon Structure and hyperon form factors from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Huey-Wen

    2007-06-11

    In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point to be 1.23(5), consistant with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(26), consistent with the Adelaide-JLab Collaboration's result. The hyperon Sigma and Xi axial coupling constants are also performed for the first time in a lattice calculation, g_SigmaSigma = 0.441(14) and g_XiXi = -0.277(11).

  19. Expression and subcellular localization of mechano-growth factor in osteoblasts under mechanical stretch

    Institute of Scientific and Technical Information of China (English)

    ZHANG BingBing; XIAN ChengYu; LUO YanFeng; WANG YuanLiang

    2009-01-01

    Mechano-growth factor (MGF) is a stretch sensitive factor in myocytes, and it might also be produced by other mechanocytes under mechanical stimulation. In this study, both the mRNA and protein expression of MGF were detected in stretched osteoblasts. Quantitative analysis showed that a cyclic stretching stimulation caused a quick and sharp increase of MGF mRNA and protein expression from a low basal level under no stretch; the mRNA and protein levels respectively peaked in 6 and 12 h to 5 and 5.2 fold over the basal level and returned to normal by 24 h. The subcellular distribution of MGF protein was revealed by immunofluorescence analysis to be restricted to the nucleus. We concluded that cyclic stretching stimulation could induce MGF expression in osteoblasts in a pulsing fashion; and the nuclear distribution of MGF suggested that MGF might act in mechanocytes as an autocrine growth factor.

  20. The Plant Heat Stress Transcription Factors (HSFs): Structure, Regulation, and Function in Response to Abiotic Stresses.

    Science.gov (United States)

    Guo, Meng; Liu, Jin-Hong; Ma, Xiao; Luo, De-Xu; Gong, Zhen-Hui; Lu, Ming-Hui

    2016-01-01

    Abiotic stresses such as high temperature, salinity, and drought adversely affect the survival, growth, and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological, and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs), including heat stress transcription factors (HSFs). HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps). In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  1. The plant heat stress transcription factors (HSFs: structure, regulation and function in response to abiotic stresses

    Directory of Open Access Journals (Sweden)

    Meng eGuo

    2016-02-01

    Full Text Available Abiotic stresses such as high temperature, salinity and drought adversely affect the survival, growth and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs, including heat stress transcription factors (HSFs. HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps. In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  2. Hypoxia inducible factor 1α promotes survival of mesenchymal stem cells under hypoxia

    Science.gov (United States)

    Lv, Bingke; Li, Feng; Fang, Jie; Xu, Limin; Sun, Chengmei; Han, Jianbang; Hua, Tian; Zhang, Zhongfei; Feng, Zhiming; Jiang, Xiaodan

    2017-01-01

    Mesenchymal stem cells (MSCs) are ideal materials for cell therapy. Research has indicated that hypoxia benefits MSC survival, but little is known about the underlying mechanism. This study aims to uncover potential mechanisms involving hypoxia inducible factor 1α (HIF1A) to explain the promoted MSC survival under hypoxia. MSCs were obtained from Sprague-Dawley rats and cultured under normoxia or hypoxia condition. The overexpression vector or small interfering RNA of Hif1a gene was transfected to MSCs, after which cell viability, apoptosis and expression of HIF1A were analyzed by MTT assay, flow cytometry, qRT-PCR and Western blot. Factors in p53 pathway were detected to reveal the related mechanisms. Results showed that hypoxia elevated MSCs viability and up-regulated HIF1A (P cell CLL/lymphoma 2 (BCL2) expression had the opposite pattern (P cell therapy.

  3. The Transport Properties of Concrete under the Simultaneous Coupling of Fatigue Load and Environment Factors

    Institute of Scientific and Technical Information of China (English)

    WANG Caihui; SUN Wei; JING Jinyang; HAN Jiande; RONG Hui

    2012-01-01

    A set of coupling experimental instrument was designed to study the transport properties of chloride ion in concrete under simultaneous coupling action of fatigue load and environmental factors.Firstly the water-saturated performance of modern concrete was investigated,then diffusion performance of chloride ion under different stress levels and different temperature were studied respectively; meanwhile,the timedependent behavior of the chloride ion diffusion in concrete was also researched.The results showed that the saturation degree of concrete can reach as high as 99%.Besides,diffusion coefficient of chloride ion increased with increasing of the stress level and temperature,and when the stress level and temperature are at 0.6 and 60 ℃ respectively,the diffusion coefficient is 6.3 × 10 14 m2/s,moreover the diffusion coefficient of chloride ion in concrete decreased with time under the simultaneous coupling action of fatigue load and environment factors.

  4. Verrucomicrobial community structure and abundance as indicators for changes in chemical factors linked to soil fertility.

    Science.gov (United States)

    Navarrete, Acacio Aparecido; Soares, Tielle; Rossetto, Raffaella; van Veen, Johannes Antonie; Tsai, Siu Mui; Kuramae, Eiko Eurya

    2015-09-01

    Here we show that verrucomicrobial community structure and abundance are extremely sensitive to changes in chemical factors linked to soil fertility. Terminal restriction fragment length polymorphism fingerprint and real-time quantitative PCR assay were used to analyze changes in verrucomicrobial communities associated with contrasting soil nutrient conditions in tropical regions. In case study Model I ("Slash-and-burn deforestation") the verrucomicrobial community structures revealed disparate patterns in nutrient-enriched soils after slash-and-burn deforestation and natural nutrient-poor soils under an adjacent primary forest in the Amazonia (R = 0.819, P = 0.002). The relative proportion of Verrucomicrobia declined in response to increased soil fertility after slash-and-burn deforestation, accounting on average, for 4 and 2 % of the total bacterial signal, in natural nutrient-poor forest soils and nutrient-enriched deforested soils, respectively. In case study Model II ("Management practices for sugarcane") disparate patterns were revealed in sugarcane rhizosphere sampled on optimal and deficient soil fertility for sugarcane (R = 0.786, P = 0.002). Verrucomicrobial community abundance in sugarcane rhizosphere was negatively correlated with soil fertility, accounting for 2 and 5 % of the total bacterial signal, under optimal and deficient soil fertility conditions for sugarcane, respectively. In nutrient-enriched soils, verrucomicrobial community structures were related to soil factors linked to soil fertility, such as total nitrogen, phosphorus, potassium and sum of bases, i.e., the sum of calcium, magnesium and potassium contents. We conclude that community structure and abundance represent important ecological aspects in soil verrucomicrobial communities for tracking the changes in chemical factors linked to soil fertility under tropical environmental conditions.

  5. An efficient block variant of robust structured multifrontal factorization method

    Institute of Scientific and Technical Information of China (English)

    Zuo Xian-Yu; Mo Ze-Yao; Gu Tong-Xiang

    2013-01-01

    Based on the two-dimensional three-temperature (2D3T) radiation diffusion equations and its discrete system,using the block diagonal structure of the three-temperature matrix,the reordering and symbolic decomposition parts of the RSMF method are replaced with corresponding block operation in order to improve the solution efficiency.We call this block form method block RSMF (in brief,BRSMF) method.The new BRSMF method not only makes the reordering and symbolic decomposition become more effective,but also keeps the cost of numerical factorization from increasing and ensures the precision of solution very well.The theoretical analysis of the computation complexity about the new BRSMF method shows that the solution efficiency about the BRSMF method is higher than the original RSMF method.The numerical experiments also show that the new BRSMF method is more effective than the original RSMF method.

  6. Wettability, soil organic matter and structure-properties of typical chernozems under the forest and under the arable land

    Science.gov (United States)

    Bykova, Galina; Umarova, Aminat; Tyugai, Zemfira; Milanovskiy, Evgeny; Shein, Evgeny

    2017-04-01

    Intensive tillage affects the properties of soil: decrease in content of soil organic matter and in hydrophobicity of the soil's solid phase, the reduction of amount of water stable aggregates - all this leads to deterioration of the structure of the soil and affects the process of movement of moisture in the soil profile. One of the hypotheses of soil's structure formation ascribes the formation of water stable aggregates with the presence of hydrophobic organic substances on the surface of the soil's solid phase. The aim of this work is to study the effect of tillage on properties of typical chernozems (pachic Voronic Chernozems, Haplic Chernozems) (Russia, Kursk region), located under the forest and under the arable land. The determination of soil-water contact angle was performed by a Drop Shape Analyzer DSA100 (Krüss GmbH, Germany) by the static sessile drop method. For all samples the content of total and organic carbon by dry combustion in oxygen flow and the particle size distribution by the laser diffraction method on the device Analysette 22 comfort, FRITCH, Germany were determined. The estimation of aggregate composition was performed by dry sieving (AS 200, Retsch, Germany), the content of water stable aggregates was estimated by the Savvinov method. There was a positive correlation between the content of organic matter and soil's wettability in studied soils, a growth of contact angle with the increasing the content of organic matter. Under the forest the content of soil organic matter was changed from 6,41% on the surface up to 1,9% at the depth of 100 cm. In the Chernozem under the arable land the organic carbon content in arable horizon is almost two times less. The maximum of hydrophobicity (78.1o) was observed at the depth of 5 cm under the forest. In the profile under the arable land the contact angle value at the same depth was 50o. The results of the structure analysis has shown a decrease in the content of agronomically valuable and water

  7. Portuguese validation of the Short Health Anxiety Inventory: Factor structure, reliability, and factor invariance.

    Science.gov (United States)

    Morales, Alexandra; Reis, Sibília; Espada, José P; Orgilés, Mireia

    2016-09-01

    The Short Health Anxiety Inventory is a brief instrument to assess health anxiety widely used across countries; however, no validated version is available for Portuguese-speaking population. Factorial structure, reliability, and equivalency factor with the Spanish version were analyzed with Portuguese adolescents aged 14-18 years. A Portuguese adolescent cohort ( N = 629) and a comparative Spanish adolescent cohort ( N = 1502) were evaluated. The original two-factor version was the best fitting model for the Portuguese version. The reliability was excellent. Complete measurement invariance across both countries was supported. The Portuguese version of the Short Health Anxiety Inventory is a valid screening inventory to assess health anxiety in adolescents.

  8. The p Factor: One General Psychopathology Factor in the Structure of Psychiatric Disorders?

    Science.gov (United States)

    Caspi, Avshalom; Houts, Renate M.; Belsky, Daniel W.; Goldman-Mellor, Sidra J.; Harrington, HonaLee; Israel, Salomon; Meier, Madeline H.; Ramrakha, Sandhya; Shalev, Idan; Poulton, Richie; Moffitt, Terrie E.

    2013-01-01

    Mental disorders traditionally have been viewed as distinct, episodic, and categorical conditions. This view has been challenged by evidence that many disorders are sequentially comorbid, recurrent/chronic, and exist on a continuum. Using the Dunedin Multidisciplinary Health and Development Study, we examined the structure of psychopathology, taking into account dimensionality, persistence, co-occurrence, and sequential comorbidity of mental disorders across 20 years, from adolescence to midlife. Psychiatric disorders were initially explained by three higher-order factors (Internalizing, Externalizing, and Thought Disorder) but explained even better with one General Psychopathology dimension. We have called this dimension the p factor because it conceptually parallels a familiar dimension in psychological science: the g factor of general intelligence. Higher p scores are associated with more life impairment, greater familiality, worse developmental histories, and more compromised early-life brain function. The p factor explains why it is challenging to find causes, consequences, biomarkers, and treatments with specificity to individual mental disorders. Transdiagnostic approaches may improve research. PMID:25360393

  9. Response Analysis for Steel Reinforced Concrete Frame Structures under Earthquake Load

    OpenAIRE

    Hua Wei; Jiye Zhang; Haijun Wang

    2013-01-01

    In order to understand the whole process of the steel reinforced concrete frame structure from elastic to elasto-plastic cracking gradually, damage until the collapse, the elasto-plastic finite element analysis theory and ETABS structural analysis software were used, then the spatial three-dimensional truss system model of frame structures was established. Based on the analysis of the elasto-plastic response for the frame structure under one-dimensional and two-dimensional earthquake load, th...

  10. Changes of structure and crystallographic texture of cladding tubes from austenitic steel under thermal creep testing

    Science.gov (United States)

    Perlovich, Yu; Isaenkova, M.; Fesenko, V.; Dobrokhotov, P.; Tselishchev, A.

    2016-04-01

    The process of changes in structure and crystallographic texture of cladding tubes from austenitic steel ChS68 under thermal creep testing were studied. Testing of tubes was conducted at the temperature 700 oC in the air by their stretching in axial direction under the stress 160 MPa until rupture. By data of phase and texture analysis a number of processes, accompanying plastic deformation of tubes during thermal creep tests at elevated temperature, were identified. The main texture components of original tube, as well as texture components of different parts of the tested tube are {110} and {112}. In the rupture zone the component of the texture of tension with axis along the tube axis becomes stronger. This effect is connected with activation of dislocation slip in the deformed area of tested tube near the new-formed neck. At the same time the character of texture changes in the zone of tube rupture indicates to development of the dynamic recrystallization, conditioned by the total influence of all factors, which control the passage in the tube of thermal creep. In addition, it was revealed the activation of martensitic transformations in the zone of maximal deformation of tube as a result of its creep tests.

  11. DYNAMIC CHARACTERISTIC ANALYSIS OF FUZZY- STOCHASTIC TRUSS STRUCTURES BASED ON FUZZY FACTOR METHOD AND RANDOM FACTOR METHOD

    Institute of Scientific and Technical Information of China (English)

    MA Juan; CHEN Jian-jun; XU Ya-lan; JIANG Tao

    2006-01-01

    A new fuzzy stochastic finite element method based on the fuzzy factor method and random factor method is given and the analysis of structural dynamic characteristic for fuzzy stochastic truss structures is presented. Considering the fuzzy randomness of the structural physical parameters and geometric dimensions simultaneously, the structural stiffness and mass matrices are constructed based on the fuzzy factor method and random factor method; from the Rayleigh's quotient of structural vibration, the structural fuzzy random dynamic characteristic is obtained by means of the interval arithmetic;the fuzzy numeric characteristics of dynamic characteristic are then derived by using the random variable's moment function method and algebra synthesis method. Two examples are used to illustrate the validity and rationality of the method given. The advantage of this method is that the effect of the fuzzy randomness of one of the structural parameters on the fuzzy randomness of the dynamic characteristic can be reflected expediently and objectively.

  12. Simulation of the Crashing of Sandwich Structures under Impact Loads by Movable Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    HUANG De-wu; HUANG Hai; SONG Yi; A I Dmitriev; E V Shilko; S G Psakhie

    2005-01-01

    Movable cellular automata (MCA) method is applied in the analysis of dynamic characters of ceramic armor composite structures under impact loading. As a new approach, MCA is different from the traditional numerical methods such as the finite element method and boundary element method. Based on the theory of particle mechanics, MCA is applied as a powerful tool in solving specific structural analysis of materials loss and penetrating damages. In this paper the method is used to study responses of multi-layered ceramic plates as a base of armor structures under impact loading, thus assisting further investigations in the crashing process and to improve ceramic armor structures.

  13. Detection of the support damage of spatial steel structures under earthquakes based on shaking table test

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    There are always some local damages in spatial steel structures induced by strong earthquakes, such as welding cracks of steel nodes,anchor loose of supports etc.If these local damages of spatial steel structures occur,there will be serious dangers to the structural safety.In order to detect the position of local damage under earthquake quickly and accurately,the method of support damage diagnosis of spatial steel structures under earthquakes is studied by using wavelet packet decomposition,data fusion a...

  14. Structural Analysis of the Factors Influencing the Financing of Forestry Enterprises Based on Interpretive Structural Modeling(ISM)

    Institute of Scientific and Technical Information of China (English)

    Zhen; WANG; Weiping; LIU; Xiaomin; JIANG

    2015-01-01

    Through the collection of related literature,we point out the six major factors influencing China’s forestry enterprises’ financing: insufficient national support; regulations and institutional environmental factors; narrow channels of financing; inappropriate existing mortgagebacked approach; forestry production characteristics; forestry enterprises’ defects. Then,we use interpretive structural modeling( ISM) from System Engineering to analyze the structure of the six factors and set up ladder-type structure. We put three factors including forestry production characteristics,shortcomings of forestry enterprises and regulatory,institutional and environmental factors as basic factors and put other three factors as important factors. From the perspective of the government and enterprises,we put forward some personal advices and ideas based on the basic factors and important factors to ease the financing difficulties of forestry enterprises.

  15. Structure and properties of loaded silica contacts during pressure solution: impedance spectroscopy measurements under hydrothermal conditions

    NARCIS (Netherlands)

    Noort, R. van; Spiers, C.J.; Peach, C.J.

    2011-01-01

    In order to investigate directly the structure and properties of grain boundaries in silicatematerials undergoing pressure solution, in situmeasurements of these properties are required. We report electrical impedance spectroscopy measurements, performed, under hydrothermal conditions,

  16. Factorial Structure of the Career Decision Scale: Incremental Validity of the Five-Factor Domains

    Science.gov (United States)

    Feldt, Ronald C.; Ferry, Ashley; Bullock, Melinda; Camarotti-Carvalho, Ana; Collingwood, Melinda; Eilers, Scott; Meyer, Luke; Nurre, Emily; Woelfel, Cheryl

    2010-01-01

    For comparison of one-, three-, and four-factor structures of the Indecision scale of the Career Decision Scale, results of confirmatory factor analysis (N = 686) indicated the best fit for the three-factor structure. Multiple regression analysis results indicated incremental validity of the five-factor model for predicting dimensions of career…

  17. Factorial Structure of the Career Decision Scale: Incremental Validity of the Five-Factor Domains

    Science.gov (United States)

    Feldt, Ronald C.; Ferry, Ashley; Bullock, Melinda; Camarotti-Carvalho, Ana; Collingwood, Melinda; Eilers, Scott; Meyer, Luke; Nurre, Emily; Woelfel, Cheryl

    2010-01-01

    For comparison of one-, three-, and four-factor structures of the Indecision scale of the Career Decision Scale, results of confirmatory factor analysis (N = 686) indicated the best fit for the three-factor structure. Multiple regression analysis results indicated incremental validity of the five-factor model for predicting dimensions of career…

  18. EVALUATION OF STRESS-STRAIN STATE OF CONSTRUCTION STRUCTURES UNDER SEISMIC LOADS EXPOSURE

    Directory of Open Access Journals (Sweden)

    Maryenkov M.G.

    2015-12-01

    Full Text Available The results of spatial interaction evaluation of the elements in the "basis - foundation - structure" system under seismic loads exposure were presented in this paper. The oscillation damping processes in the ground and engineering constructions were taken into account. Calculations of the structure on pile foundation and comparison of the results from the first form of natural vibrations were conducted. The comparison of the oscillation amplitudes of the construction under elastic and non-linear deformations was made.

  19. Factor structure of the human gamma band oscillatory response to visual (contrast) stimulation.

    Science.gov (United States)

    Carozzo, Simone; De Carli, Fabrizio; Beelke, Manolo; Saturno, Moreno; Garbarino, Sergio; Martello, Cristina; Sannita, Walter G

    2004-07-01

    Visual contrast stimulation evokes in man an oscillatory mass response at approximately 20.0-35.0 Hz, consistent with stimulus-dependent synchronous oscillations in multiunit animal recordings from visual cortex, but shorter in duration and phase-locked to stimulus. A factor analysis was applied to characterize the signal structure under stimulus conditions inducing an oscillatory response and to identify possible subcomponents in normal volunteers. Contrast stimuli were gratings with a sinusoidal luminance profile (9.0 degrees; 5.0 cycle/degree; 80% contrast; reversal 1.06 Hz). The amplitude spectrum of the signal was computed by Discrete Fourier Transform (DFT) and the oscillatory response was separated from the corresponding visually evoked potential (VEP) by DFT high-pass filter at 19.0 Hz. Nine consecutive waves were identified in all subjects (60 volunteers), with amplitudes/latencies consistent with normative studies. A factor analysis was computed 1- in the frequency domain, on the amplitude values of the signal components (2 Hz resolution), and 2- in the time domain, on the latencies/amplitudes of the averaged VEP and oscillatory responses. (1) Two non-overlapping factors accounted for the approximately 2-20.0 and approximately 20.0-40.0 Hz signal components, with separation of the approximately 20.0-35.0 Hz oscillatory response from low frequency VEPs. (2) Two factors on latencies and one factor on amplitudes (independent of each other and from those of VEPs) accounted for the average approximately 20.0-35.0 Hz oscillatory response. The factor structure further indicates an oscillatory structure and some independence from conventional VEPs of the human oscillatory response to contrast, with a separation between the oscillatory response early and late waves possibly reflecting functional differences.

  20. A combined model of human erythropoiesis and granulopoiesis under growth factor and chemotherapy treatment.

    Science.gov (United States)

    Schirm, Sibylle; Engel, Christoph; Loeffler, Markus; Scholz, Markus

    2014-05-26

    Haematotoxicity of conventional chemotherapies often results in delays of treatment or reduction of chemotherapy dose. To ameliorate these side-effects, patients are routinely treated with blood transfusions or haematopoietic growth factors such as erythropoietin (EPO) or granulocyte colony-stimulating factor (G-CSF). For the latter ones, pharmaceutical derivatives are available, which differ in absorption kinetics, pharmacokinetic and -dynamic properties. Due to the complex interaction of cytotoxic effects of chemotherapy and the stimulating effects of different growth factor derivatives, optimal treatment is a non-trivial task. In the past, we developed mathematical models of thrombopoiesis, granulopoiesis and erythropoiesis under chemotherapy and growth-factor applications which can be used to perform clinically relevant predictions regarding the feasibility of chemotherapy schedules and cytopenia prophylaxis with haematopoietic growth factors. However, interactions of lineages and growth-factors were ignored so far. To close this gap, we constructed a hybrid model of human granulopoiesis and erythropoiesis under conventional chemotherapy, G-CSF and EPO applications. This was achieved by combining our single lineage models of human erythropoiesis and granulopoiesis with a common stem cell model. G-CSF effects on erythropoiesis were also implemented. Pharmacodynamic models are based on ordinary differential equations describing proliferation and maturation of haematopoietic cells. The system is regulated by feedback loops partly mediated by endogenous and exogenous EPO and G-CSF. Chemotherapy is modelled by depletion of cells. Unknown model parameters were determined by fitting the model predictions to time series data of blood counts and cytokine profiles. Data were extracted from literature or received from cooperating clinical study groups. Our model explains dynamics of mature blood cells and cytokines after growth-factor applications in healthy volunteers

  1. The Evolution of Protein Structures and Structural Ensembles Under Functional Constraint

    Directory of Open Access Journals (Sweden)

    David A. Liberles

    2011-10-01

    Full Text Available Protein sequence, structure, and function are inherently linked through evolution and population genetics. Our knowledge of protein structure comes from solved structures in the Protein Data Bank (PDB, our knowledge of sequence through sequences found in the NCBI sequence databases (http://www.ncbi.nlm.nih.gov/, and our knowledge of function through a limited set of in-vitro biochemical studies. How these intersect through evolution is described in the first part of the review. In the second part, our understanding of a series of questions is addressed. This includes how sequences evolve within structures, how evolutionary processes enable structural transitions, how the folding process can change through evolution and what the fitness impacts of this might be. Moving beyond static structures, the evolution of protein kinetics (including normal modes is discussed, as is the evolution of conformational ensembles and structurally disordered proteins. This ties back to a question of the role of neostructuralization and how it relates to selection on sequences for functions. The relationship between metastability, the fitness landscape, sequence divergence, and organismal effective population size is explored. Lastly, a brief discussion of modeling the evolution of sequences of ordered and disordered proteins is entertained.

  2. Examining the Factor Structure of Anxiety and Depression Symptom Items Among Adolescents in Santiago, Chile.

    Science.gov (United States)

    Bares, Cristina B; Andrade, Fernando; Delva, Jorge; Grogan-Kaylor, Andrew

    2011-01-01

    The co-occurrence of emotional disorders among adolescents has received considerable empirical attention. This study aims to contribute to the understanding of co-occurring anxiety and depression by examining the factor structure of the Youth Self-Report used with a sample of low-income adolescents from Santiago, Chile. Data from two independent, randomly selected subsamples were analyzed using exploratory and confirmatory factor analyses. Results indicate the best fit for the data is a two-factor model of anxiety and depression symptoms, which factors anxiety and depression into separate latent constructs. Because the findings show that anxiety and depression are not measured by the same factor in this international sample, the results imply that a valid and useful distinction exists between these constructs. That these constructs are found to be separate factors suggests that anxiety and depression may have separate etiologies and consequences, which might be best addressed by separate intervention components. These findings are consistent with the viewpoint that anxiety and depression constructs have similar emotional features and, despite sharing a common underlying internalizing disorder, distinct items capture aspects of each construct.

  3. Stress state of thin – walled member of the structure with operation damages under nonuniform loading

    Directory of Open Access Journals (Sweden)

    В.В. Астанін

    2004-01-01

    Full Text Available  The publication is dedicated to determining of stress state in particular the stress concentration factors for thin – walled members of the structures subject to nonuniform tension. A structure member has obtained the operation damage generation by corrosion and other causes.

  4. Structural Evolution of Human Recombinant alfaB-Crystallin under UV Irradiation

    DEFF Research Database (Denmark)

    Sugiyama, Masaaki; Fujii, Noriko; Morimoto, Yukio;

    2008-01-01

    External stresses cause certain proteins to lose their regular structure and aggregate. In order to clarify this abnormal aggregation process, a structural evolution of human recombinant aB-crystallin under UV irradiation was observed with in situ small-angle neutron scattering. The abnormal...

  5. The network structure of human personality according to the NEO-PI-R: matching network community structure to factor structure.

    Directory of Open Access Journals (Sweden)

    Rutger Goekoop

    Full Text Available INTRODUCTION: Human personality is described preferentially in terms of factors (dimensions found using factor analysis. An alternative and highly related method is network analysis, which may have several advantages over factor analytic methods. AIM: To directly compare the ability of network community detection (NCD and principal component factor analysis (PCA to examine modularity in multidimensional datasets such as the neuroticism-extraversion-openness personality inventory revised (NEO-PI-R. METHODS: 434 healthy subjects were tested on the NEO-PI-R. PCA was performed to extract factor structures (FS of the current dataset using both item scores and facet scores. Correlational network graphs were constructed from univariate correlation matrices of interactions between both items and facets. These networks were pruned in a link-by-link fashion while calculating the network community structure (NCS of each resulting network using the Wakita Tsurumi clustering algorithm. NCSs were matched against FS and networks of best matches were kept for further analysis. RESULTS: At facet level, NCS showed a best match (96.2% with a 'confirmatory' 5-FS. At item level, NCS showed a best match (80% with the standard 5-FS and involved a total of 6 network clusters. Lesser matches were found with 'confirmatory' 5-FS and 'exploratory' 6-FS of the current dataset. Network analysis did not identify facets as a separate level of organization in between items and clusters. A small-world network structure was found in both item- and facet level networks. CONCLUSION: We present the first optimized network graph of personality traits according to the NEO-PI-R: a 'Personality Web'. Such a web may represent the possible routes that subjects can take during personality development. NCD outperforms PCA by producing plausible modularity at item level in non-standard datasets, and can identify the key roles of individual items and clusters in the network.

  6. Response Analysis for Steel Reinforced Concrete Frame Structures under Earthquake Load

    Directory of Open Access Journals (Sweden)

    Hua Wei

    2013-07-01

    Full Text Available In order to understand the whole process of the steel reinforced concrete frame structure from elastic to elasto-plastic cracking gradually, damage until the collapse, the elasto-plastic finite element analysis theory and ETABS structural analysis software were used, then the spatial three-dimensional truss system model of frame structures was established. Based on the analysis of the elasto-plastic response for the frame structure under one-dimensional and two-dimensional earthquake load, the interbedded displacement angle-time curve and horizontal displacement-time curve were obtained. Through the analysis of the model, the sequence of appearance of plastic hinges in the frame structure under earthquake load was cleared and the weak location of the frame structure was detected.

  7. Are familial factors underlying the association between socioeconomic position and prescription medicine?

    DEFF Research Database (Denmark)

    Madsen, Mia; Andersen, Per Kragh; Gerster, Mette;

    2013-01-01

    OBJECTIVES: Although well established, the association between socioeconomic position and health and health behaviour is not clearly understood, and it has been speculated that familial factors, for example, dispositional factors or exposures in the rearing environment, may be underlying...... analyses were compared. RESULTS: An inverse social gradient in filling of prescriptions for all-purpose and system-specific drugs was observed in the unpaired analyses. In the intrapair analyses, associations were attenuated some in DZSS and more in MZ twins. Filling of drugs targeting the nervous system...... was still strongly associated with income in the intrapair analyses. CONCLUSIONS: Familial factors seem to account for part of the observed social inequality in filling of prescription medicine....

  8. Are the educational differences in incidence of cardiovascular disease explained by underlying familial factors?

    DEFF Research Database (Denmark)

    Madsen, Mia; Andersen, Per Kragh; Gerster, Mette;

    2014-01-01

    To isolate the effect of education from the influence of potential underlying factors, we investigated the association of education with the risk of cardiovascular disease (CVD) and ischemic heart disease (IHD) using twin data to adjust for familial factors shared within twins, including genetic...... make-up and childhood environment. The study was based on data from the Danish Twin Registry linked to administrative and heath registers in Statistics Denmark. A total of 11,968 monozygotic and 20,464 dizygotic same sexed twins were followed from 1980 to 2009, including more than 8000 events of CVD....... Unpaired and intra-pair analyses were compared. In the unpaired analyses, an inverse educational gradient in CVD- and IHD risk was observed. This association was not replicated in the intra-pair analyses that control for shared familial factors exploiting that twins share their intrauterine- and childhood...

  9. [Dietary factors and their relation to appetite in children under two years with mild malnutrition].

    Science.gov (United States)

    Quijada, Mariana Martínez; Gutiérrez, María Luisa Alvarez

    2012-06-01

    Malnutrition is conditioned by a series of factors, among them the dietary factors, which include appetite, eating behaviors and habits. In order to assess these factors, the following objective was pursued: describe the dietary factors and their relation to appetite in children under two years of age with mild malnutrition. A correlational study was conducted. The sample consisted of all children under two years of age (n = 168) diagnosed with primary (mild) malnutrition, who attended consultation at the Centro de Atención Nutricional Infantil Antímano, CANIA, during the period 2000-2008. The results showed intake of energy and macronutrients was lower than the individual requirement; iron intake children showed rebellious behavior and caregivers were permissive. Protein adequacy, vegetable and whole milk consumption frequency, preparation type, identification of refusals and preferences, place and duration of meals, and child-caregiver interaction at mealtimes were significantly associated with appetite; if we consider this last one as a guide and we try to modify inadequate eating behaviors and habits, we will generate an impact over the child appetite that could improve the food consumption and prevent malnutrition.

  10. Biology of Bone Tissue: Structure, Function, and Factors That Influence Bone Cells.

    Science.gov (United States)

    Florencio-Silva, Rinaldo; Sasso, Gisela Rodrigues da Silva; Sasso-Cerri, Estela; Simões, Manuel Jesus; Cerri, Paulo Sérgio

    2015-01-01

    Bone tissue is continuously remodeled through the concerted actions of bone cells, which include bone resorption by osteoclasts and bone formation by osteoblasts, whereas osteocytes act as mechanosensors and orchestrators of the bone remodeling process. This process is under the control of local (e.g., growth factors and cytokines) and systemic (e.g., calcitonin and estrogens) factors that all together contribute for bone homeostasis. An imbalance between bone resorption and formation can result in bone diseases including osteoporosis. Recently, it has been recognized that, during bone remodeling, there are an intricate communication among bone cells. For instance, the coupling from bone resorption to bone formation is achieved by interaction between osteoclasts and osteoblasts. Moreover, osteocytes produce factors that influence osteoblast and osteoclast activities, whereas osteocyte apoptosis is followed by osteoclastic bone resorption. The increasing knowledge about the structure and functions of bone cells contributed to a better understanding of bone biology. It has been suggested that there is a complex communication between bone cells and other organs, indicating the dynamic nature of bone tissue. In this review, we discuss the current data about the structure and functions of bone cells and the factors that influence bone remodeling.

  11. Parametric Equation of Stress Concentration Factor for Circular X-Joints Under Axial Loads

    Institute of Scientific and Technical Information of China (English)

    QU Shu-ying; ZHANG Guo-dong; ZHANG Bao-feng; WANG Xin-jian

    2007-01-01

    In engineering practice,tubular X-joints have been widely used in offshore structures.The fatigue failure of tubular X-joints in offshore engineering is mainly caused by axial tensile stress.In this study,the stress concentration factor distribution along the weld toe in the hot spot stress region for tubular X-joints subject to axial loads have been analyzed by use of finite element method.Through numerical analysis,it has been found that the peak stress concentration factor is located at the saddle position.Thereafter,80 models have been analyzed,and the effect of the geometric parameters of a tubular X-joint on the stress concentration factor has been investigated.Based on the experimental values of the numerical stress concentration factor,a parametric equation to calculate the stress concentration factor of tubular X-joints has been proposed.The accuracy of this equation has been verified against the requirement of the Fatigue Guidance Review Panel,and the proposed equation is found capable of producing reasonably accurate stress concentration factor values for tubular X-joints subject to axial loads.

  12. Structure and physical properties of magneto-rheological slurries under perturbation

    OpenAIRE

    De la Calleja, E. M.; J.L. Carrillo; Donado, F.

    2012-01-01

    Dispersions of micrometric magnetic particles in inert liquids acquire a complex multifractal structure when they are exposed to a static magnetic field. If in addition to the static field it is applied on the dispersion an oscillatory magnetic perturbation, the structure formed by the particles, and consequently, some of the physical properties of the system, can be strongly affected. Under certain conditions, by the influence of the perturbation, the structure in the dispersion can be recon...

  13. Hypothalamic corticotropin-releasing factor is centrally involved in learning under moderate stress.

    Science.gov (United States)

    Lucas, Morgan; Chen, Alon; Richter-Levin, Gal

    2013-08-01

    The corticotropin-releasing factor (CRF) neuropeptide is found to have a pivotal role in the regulation of the behavioral and neuroendocrine responses to stressful challenges. Here, we studied the involvement of the hypothalamic CRF in learning under stressful conditions. We have used a site-specific viral approach to knockdown (KD) CRF expression in the paraventricular nucleus of the hypothalamus (PVN). The two-way shuttle avoidance (TWSA) task was chosen to assess learning and memory under stressful conditions. Control animals learned to shuttle from one side to the other to avoid electrical foot shock by responding to a tone. Novel object and social recognition tasks were used to assess memory under less stressful conditions. KD of PVN-CRF expression decreased the number of avoidance responses in a TWSA session under moderate (0.8 mA), but not strong (1.5 mA), stimulus intensity compared to control rats. On the other hand, KD of PVN-CRF had no effect on memory performance in the less stressful novel object or social recognition tasks. Interestingly, basal or stress-induced corticosterone levels in CRF KD rats were not significantly different from controls. Taken together, the data suggest that the observed impairment was not a result of alteration in HPA axis activity, but rather due to reduced PVN-CRF activity on other brain areas. We propose that hypothalamic CRF is centrally involved in learning under moderate stressful challenge. Under 'basal' (less stressful) conditions or when the intensity of the stress is more demanding, central CRF ceases to be the determinant factor, as was indicated by performances in the TWSA with higher stimulus intensity or in the less stressful tasks of object and social recognition.

  14. Dynamic-structure-factor measurements on a model Lorentz gas

    Science.gov (United States)

    Egelstaff, P. A.; Eder, O. J.; Glaser, W.; Polo, J.; Renker, B.; Soper, A. K.

    1990-02-01

    A model system for the Lorentz gas can be made [Eder, Chen, and Egelstaff, Proc. Phys. Soc. London 89, 833 (1966); McPherson and Egelstaff, Can. J. Phys. 58, 289 (1980)] by mixing small quantities of hydrogen with an argon host. For neutron-scattering experiments the large H-to-Ar cross section ratio (~200) makes the argon relatively invisible. Dynamic-structure-factor [S(Q,ω) for H2] measurements at room temperature have been made on this system using the IN4 spectrometer at the Institute Laue Langevin, Grenoble, France. Argon densities between 1.9 and 10.5 atoms/nm3 were used for 0.4

  15. Surface layer structure and average contact temperature of copper-containing materials under dry sliding with high electric current density

    Science.gov (United States)

    Fadin, V. V.; Aleutdinova, M. I.; Rubtsov, V. Ye.; Aleutdinov, K. A.

    2016-11-01

    Dry sliding of copper and powder composites of Cu-Fe and Cu-Fe-graphite compositions against 1045 steel under electric current of contact density higher than 250 A/cm2 has been studied, which demonstrated the change in surface layer structure and formation of tribolayer consisting of iron, copper and FeO oxide. Signs of quasi-viscous flow of worn surface were observed. It was noted that the thin contact layer containing about 40 at % of oxygen and 40% of Fe was the main factor decreasing the adhesion interaction. It was affirmed that the introduction of graphite into the primary structure of the composite leads to rather low content of FeO oxide and to the increased tendency of surface layer to catastrophic deterioration under sliding with contact current density of about 300 A/cm2. The temperature of contact did not exceed 400°C.

  16. [Analysis on risk factors of endotracheal cuff under inflation in mechanically ventilated patients].

    Science.gov (United States)

    Fu, You; Xi, Xiuming

    2014-12-01

    To investigate the prevalent condition of endotracheal cuff pressure and risk factors for under inflation. A prospective cohort study was conducted. Patients admitted to the Department of Critical Care Medicine of Fuxing Hospital Affiliated to Capital Medical University, who were intubated with a high-volume low-pressure endotracheal tube, and had undergone mechanical ventilation for at least 48 hours, were enrolled. The endotracheal cuff pressure was determined every 8 hours by a manual manometer connected to the distal edge of the valve cuff at 07 : 00, 15 : 00, and 23 : 00. Measurement of the endotracheal cuff pressure was continued until the extubation of endotracheal or tracheostomy tube, or death of the patient. According to the incidence of under inflation of endotracheal cuff, patients were divided into the incidence of under inflation lower than 25% group (lower low cuff pressure group) and higher than 25% group (higher low cuff pressure group). The possible influencing factors were evaluated in the two groups, including body mass index (BMI), size of endotracheal tube, duration of intubation, use of sedative or analgesic, number of leaving from intensive care unit (ICU), the number of turning over the patients, and aspiration of sputum. Logistic regression analysis was used to determine risk factors for under-inflation of the endotracheal cuff. During the study period, 53 patients were enrolled. There were 812 measurements, and 46.3% of them was abnormal, and 204 times (25.1%) of under inflation of endotracheal cuff were found. There were 24 patients (45.3%) in whom the incidence of under inflation rate was higher than 25%. The average of under inflation was 7 (4, 10) times. Compared with the group with lower rate of low cuff pressure, a longer time for intubation was found in group with higher rate of low cuff pressure [hours: 162 (113, 225) vs. 118 (97, 168), Z=-2.034, P=0.042]. There were no differences between the two groups in other factors

  17. Risk Factors of Diarrhea in Children Under Five Years in Urban Slums

    Directory of Open Access Journals (Sweden)

    Balakrishna Kalakheti

    2016-12-01

    Full Text Available Introduction: Diarrhea is a leading cause of mortality in children in developing countries and the condition is worse in slums. In order to provide effective preventive and management strategies, it is important to identify factors associated with the disease. This study was carried out to investigate the risk factors of diarrhea in  children under five years of age in urban slums.   Methods: Parents of all children under five years from the urban slums of Tansen municipality, Palpa, Nepal were interviewed using a standardized pretested questionnaire and proforma. Parental variables, environmental factors, and presence of diarrhea in those children in past three months were collected by trained enumerators and the data were analyzed with statistical software SPSS-10.   Results: A total of 450 under five years children were enrolled in the study. There were 216 (48% male and 234 (52% female children with F:M ratio of 1.08:1. Occurrence of diarrhea was lower if the children were breast-fed for more than six months, well-nourished, used fountain water for drinking, or used boiled or treated water. Similarly, diarrhea prevalence was lower if father had a regular job, daily income in the family was more than one US dollar, there was a toilet in the house, practice of hand washing was followed before feeding or preparing food, or there was no child suffering from diarrhea in the neighborhood.   Conclusion: There are a few variables that are significantly related to diarrhea in children under five years of age. In order to decrease the diarrheal episodes in children in the slums of the developing countries, priority could be given in the improvement of those variables.

  18. The latent structure of loneliness: testing competing factor models of the UCLA Loneliness Scale in a large adolescent sample.

    Science.gov (United States)

    Shevlin, Mark; Murphy, Siobhan; Murphy, Jamie

    2015-04-01

    This study assessed the dimensional structure of the UCLA Loneliness Scale ([UCLA-LS], UCLA-3). Data from the Northern Ireland Young Life and Times Survey (2011), a survey of 1,434 16-year-olds, was used to examine the underlying factor structure of the scale. Confirmatory factor analysis was employed to compare alternative factor analytical models that can inform the scoring of the measure and determine the degree to which different factors provided unique predictive utility. Fit statistics indicated that the best fitting model comprised three correlated factors: Isolation, Related Connectedness, and Collective Connectedness. These findings were consistent with previous findings that identified the multidimensional nature of the UCLA-LS. The study also found evidence that the subscales were differentially associated with psychiatric morbidity as measured by the General Health Questionnaire (GHQ-12) and provides a more reliable and comprehensive framework to assess the clinical significance of loneliness.

  19. Inherent structure features of beryllium and their influence on the performance polycrystalline metal under different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Khomutov, A.M.; Mikhailov, V.S.; Pronin, V.N.; Pakhomov, Ya.D. [State Scientific Center of Russian Federation `A.A. Bochvar All-Russia Research Inst. of Inorganic Materials (VNIINM)`, Moscow (Russian Federation)

    1998-01-01

    The anisotropy of physical properties of beryllium single crystals resulting from covalent bonds in crystal lattice leads to significant residual thermal microstresses (RTM) in the polycrystalline metal. It is demonstrated experimentally that there is a simple linear dependence between the magnitude of RTM and the ultimate tensile strength. The factors controlling RTM are analysed and in the framework of powder metallurgy process the technological methods of producing beryllium with the needed properties are recommended. Primarily it is necessary to control the quantity and extent of dispersity of intergranular oxide inclusions and mean grain size in combination with the high degree of macro- and microhomogenity of the structure. The requirements to beryllium microstructure for different operating conditions including neutron fluxes and transient temperature fields are formulated. In the framework of the concept under development one can explain formerly not fully understandable effects, which are characteristic of polycrystalline beryllium such as unexpected Petch-Stro curve, the role of twinning etc., and predict new ones. In particular, it can be possible to expect the growth of ductility of high strength beryllium grades as neutron irradiated. (author)

  20. First-principles calculations of structural stability and mechanical properties of tungsten carbide under high pressure

    Science.gov (United States)

    Li, Xinting; Zhang, Xinyu; Qin, Jiaqian; Zhang, Suhong; Ning, Jinliang; Jing, Ran; Ma, Mingzhen; Liu, Riping

    2014-11-01

    The structural stability and mechanical properties of WC in WC-, MoC- and NaCl-type structures under high pressure are investigated systematically by first-principles calculations. The calculated equilibrium lattice constants at zero pressure agree well with available experimental and theoretical results. The formation enthalpy indicates that the most stable WC is in WC-type, then MoC-type finally NaCl-type. By the elastic stability criteria, it is predicted that the three structures are all mechanically stable. The elastic constants Cij, bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio ν of the three structures are studied in the pressure range from 0 to 100 GPa. Furthermore, by analyzing the B/G ratio, the brittle/ductile behavior under high pressure is assessed. Moreover, the elastic anisotropy of the three structures up to 100 GPa is also discussed in detail.

  1. NEURAL NETWORKS PREDICTION FOR SEISMIC RESPONSE OF STRUCTURE UNDER THE LEVENBERG-MARQUARDT ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    徐赵东; 沈亚鹏; 李爱群

    2003-01-01

    Objective To investigate the prediction effect of neural networks for seismic response of structure under the Levenberg-Marquardt(LM) algorithm. Results Based on identification and prediction ability of neural networks for nonlinear systems, and combined with LM algorithm, a multi-layer forward networks is adopted to predict the seismic responses of structure. The networks is trained in batch by the shaking table test data of three-floor reinforced concrete structure firstly, then the seismic responses of structure are predicted under the unused excitation data, and the predict responses are compared with the experiment responses. The error curves between the prediction and the experimental results show the efficiency of the method. Conclusion LM algorithm has very good convergence rate, and the neural networks can predict the seismic response of the structure well.

  2. The Crystal Structure and Behavior of Fenamic Acid-Acridine Complex Under High Pressure.

    Science.gov (United States)

    Jerzykiewicz, Lucjan; Sroka, Adam; Majerz, Irena

    2016-12-01

    The crystal structure of fenamic acid-acridine complex is determined by X-ray diffraction. The strong OHN hydrogen bond linking the complex components and other interactions responsible for packing of the molecules into a crystal are investigated within the Quantum Theory of Atom in Molecule theory. The crystal structure is compared with the structure optimized at B3LYP/6-311++G** level and with the theoretical structures optimized under systematically changed pressure. Analysis of the lattice constants, hydrogen bond lengths, and angles of the inter- and intramolecular hydrogen bond under compression is performed. The structural transformation observed at 5 GPa is connected with a change in the intermolecular OHN hydrogen bond. The proton shifts to acceptor and a new interaction in the crystal appears.

  3. Influence of the membrane structure plan shape on the displacements under point load

    Directory of Open Access Journals (Sweden)

    Milošević Vuk S.

    2016-01-01

    Full Text Available Deformations of membrane structures under external loads are much more prominent compared to other structures and structural materials. External area loads cause large displacements and redistribution of internal tension forces. Point loads have a less significant impact on changes of internal forces, but a more significant role in creation of local deformations. Previous researches have shown the influence of position and intensity of point loads on the deformations of membrane structures. The aim of this research is to investigate the influence of plan shape of the membrane structure on the displacements under point load. The influence of rhombic shaped plans with different diagonal lengths and ratios is explored. The research is conducted on numerical models in the specialized software Sofistik. Models are loaded with point loads in the point where diagonals intersect and the results are compared.

  4. Finding Imaging Patterns of Structural Covariance via Non-Negative Matrix Factorization

    Science.gov (United States)

    Sotiras, Aristeidis; Resnick, Susan M.; Davatzikos, Christos

    2015-01-01

    In this paper, we investigate the use of Non-Negative Matrix Factorization (NNMF) for the analysis of structural neuroimaging data. The goal is to identify the brain regions that co-vary across individuals in a consistent way, hence potentially being part of underlying brain networks or otherwise influenced by underlying common mechanisms such as genetics and pathologies. NNMF offers a directly data-driven way of extracting relatively localized co-varying structural regions, thereby transcending limitations of Principal Component Analysis (PCA), Independent Component Analysis (ICA) and other related methods that tend to produce dispersed components of positive and negative loadings. In particular, leveraging upon the well known ability of NNMF to produce parts-based representations of image data, we derive decompositions that partition the brain into regions that vary in consistent ways across individuals. Importantly, these decompositions achieve dimensionality reduction via highly interpretable ways and generalize well to new data as shown via split-sample experiments. We empirically validate NNMF in two data sets: i) a Diffusion Tensor (DT) mouse brain development study, and ii) a structural Magnetic Resonance (sMR) study of human brain aging. We demonstrate the ability of NNMF to produce sparse parts-based representations of the data at various resolutions. These representations seem to follow what we know about the underlying functional organization of the brain and also capture some pathological processes. Moreover, we show that these low dimensional representations favorably compare to descriptions obtained with more commonly used matrix factorization methods like PCA and ICA. PMID:25497684

  5. Vibrating barrier: a novel device for the passive control of structures under ground motion.

    Science.gov (United States)

    Cacciola, P; Tombari, A

    2015-07-08

    A novel device, called vibrating barrier (ViBa), that aims to reduce the vibrations of adjacent structures subjected to ground motion waves is proposed. The ViBa is a structure buried in the soil and detached from surrounding buildings that is able to absorb a significant portion of the dynamic energy arising from the ground motion. The working principle exploits the dynamic interaction among vibrating structures due to the propagation of waves through the soil, namely the structure-soil-structure interaction. The underlying theoretical aspects of the novel control strategy are scrutinized along with its numerical modelling. Closed-form solutions are also derived to design the ViBa in the case of harmonic excitation. Numerical and experimental analyses are performed in order to investigate the efficiency of the device in mitigating the effects of ground motion waves on the structural response. A significant reduction in the maximum structural acceleration of 87% has been achieved experimentally.

  6. The role of psychological and physiological factors in decision making under risk and in a dilemma

    Directory of Open Access Journals (Sweden)

    Jonas eFooken

    2016-01-01

    Full Text Available Different methods to elicit risk attitudes of individuals often provide differing results despite a common theory. Reasons for such inconsistencies may be the different influence of underlying factors in risk-taking decisions. In order to evaluate this conjecture, a better understanding of underlying factors across methods and decision contexts is desirable. In this paper we study the difference in result of two different risk elicitation methods by linking estimates of risk attitudes to gender, age and personality traits, which have been shown to be related. We also investigate the role of these factors during decision-making in a dilemma situation. For these two decision contexts we also investigate the decision-maker's physiological state during the decision, measured by heart rate variability (HRV, which we use as an indicator of emotional involvement. We found that the two elicitation methods provide different individual risk attitude measures which is partly reflected in a different gender effect between the methods. Personality traits explain only relatively little in terms of driving risk attitudes and the difference between methods. We also found that risk taking and the physiological state are related for one of the methods, suggesting that more emotionally involved individuals are more risk averse in the experiment. Finally, we found evidence that personality traits are connected to whether individuals made a decision in the dilemma situation, but risk attitudes and the physiological state were not indicative for the ability to decide in this decision context.

  7. Modelling agricultural suitability along soil transects under current conditions and improved scenario of soil factors

    Science.gov (United States)

    Abd-Elmabod, Sameh K.; Jordán, Antonio; Fleskens, Luuk; van der Ploeg, Martine; Muñoz-Rojas, Miriam; Anaya-Romero, María; van der Salm, Renée J.; De la Rosa, Diego

    2015-04-01

    limiting factor in lowlands. The decrease in the severity of soil limiting factors in the improved scenario leads to an increase of soil suitability for the twelve crops along TA and TB transects, except in segments with shallow soils and very coarse texture. In the hypothetical scenario with no limiting factors, the highest improvement on suitability is observed under perennial crops in the TA transect. Land evaluation has proved to be a good way to distinguish the best soil suitability by addressing limitations and is an essential tool for land use and climate-change adaptation planning. Keywords: Digital Elevation Model, Toposequence, MicroLEIS DSS, Almagra model, Soil quality.

  8. Reliability Analysis of Piezoelectric Truss Structures Under Joint Action of Electric and Mechanical Loading

    Institute of Scientific and Technical Information of China (English)

    YANG Duo-he; AN Wei-guang; ZHU Rong-rong; MIAO Han

    2006-01-01

    Based on the finite element method(FEM) for the dynamical analysis of piezoelectric truss structures, the expressions of safety margins of strength fracture and damage electric field in the structure element are given considering electromechanical coupling effect under the joint action of electric and mechanical load. By importing the stochastic FEM,reliability of piezoelectric truss structures is analyzed by solving for partial derivative in the process of solving dynamical response of structure system with mode-superposition method. The influence of electromechanical coupling effect to reliability index is then analyzed through an example.

  9. Response of Box-Type Structures Under Internal-Blast Loading

    Institute of Scientific and Technical Information of China (English)

    WANG Zhongqi; WU Jianguo; BAI Chunhua; LU Yong

    2006-01-01

    The tests of box-type structures under internal-blast loading are carried out.Then a numerical analysis of the test structures is done using a fully coupled numerical finite element model.The break-up process of the structure is simulated.The failure modes of the simulated structure agree well with the experimental results.The effects of the size of the reinforcing bars and the detailing of connections among the rebars in the concrete on the throw velocity of the fragments are discussed.

  10. Non-stationary random vibration analysis of structures under multiple correlated normal random excitations

    Science.gov (United States)

    Li, Yanbin; Mulani, Sameer B.; Kapania, Rakesh K.; Fei, Qingguo; Wu, Shaoqing

    2017-07-01

    An algorithm that integrates Karhunen-Loeve expansion (KLE) and the finite element method (FEM) is proposed to perform non-stationary random vibration analysis of structures under excitations, represented by multiple random processes that are correlated in both time and spatial domains. In KLE, the auto-covariance functions of random excitations are discretized using orthogonal basis functions. The KLE for multiple correlated random excitations relies on expansions in terms of correlated sets of random variables reflecting the cross-covariance of the random processes. During the response calculations, the eigenfunctions of KLE used to represent excitations are applied as forcing functions to the structure. The proposed algorithm is applied to a 2DOF system, a 2D cantilever beam and a 3D aircraft wing under both stationary and non-stationary correlated random excitations. Two methods are adopted to obtain the structural responses: a) the modal method and b) the direct method. Both the methods provide the statistics of the dynamic response with sufficient accuracy. The structural responses under the same type of correlated random excitations are bounded by the response obtained by perfectly correlated and uncorrelated random excitations. The structural response increases with a decrease in the correlation length and with an increase in the correlation magnitude. The proposed methodology can be applied for the analysis of any complex structure under any type of random excitation.

  11. Research on the influencing factors of reverse logistics carbon footprint under sustainable development.

    Science.gov (United States)

    Sun, Qiang

    2016-12-09

    With the concerns of ecological and circular economy along with sustainable development, reverse logistics has attracted the attention of enterprise. How to achieve sustainable development of reverse logistics has important practical significance of enhancing low carbon competitiveness. In this paper, the system boundary of reverse logistics carbon footprint is presented. Following the measurement of reverse logistics carbon footprint and reverse logistics carbon capacity is provided. The influencing factors of reverse logistics carbon footprint are classified into five parts such as intensity of reverse logistics, energy structure, energy efficiency, reverse logistics output, and product remanufacturing rate. The quantitative research methodology using ADF test, Johansen co-integration test, and impulse response is utilized to interpret the relationship between reverse logistics carbon footprint and the influencing factors more accurately. This research finds that energy efficiency, energy structure, and product remanufacturing rate are more capable of inhibiting reverse logistics carbon footprint. The statistical approaches will help practitioners in this field to structure their reverse logistics activities and also help academics in developing better decision models to reduce reverse logistics carbon footprint.

  12. Examining the Factor Structure and Hierarchical Nature of the Quality of Life Construct

    Science.gov (United States)

    Wang, Mian; Schalock, Robert L.; Verdugo, Miguel A.; Jenaro, Christina

    2010-01-01

    There is considerable debate in the area of individual quality of life research regarding the factor structure and hierarchical nature of the quality of life construct. Our purpose in this study was to test via structural equation modeling an a priori quality of life model consisting of eight first-order factors and one second-order factor. Data…

  13. Evaluating WAIS-IV structure through a different psychometric lens: structural causal model discovery as an alternative to confirmatory factor analysis.

    Science.gov (United States)

    van Dijk, Marjolein J A M; Claassen, Tom; Suwartono, Christiany; van der Veld, William M; van der Heijden, Paul T; Hendriks, Marc P H

    2017-07-20

    Since the publication of the WAIS-IV in the U.S. in 2008, efforts have been made to explore the structural validity by applying factor analysis to various samples. This study aims to achieve a more fine-grained understanding of the structure of the Dutch language version of the WAIS-IV (WAIS-IV-NL) by applying an alternative analysis based on causal modeling in addition to confirmatory factor analysis (CFA). The Bayesian Constraint-based Causal Discovery (BCCD) algorithm learns underlying network structures directly from data and assesses more complex structures than is possible with factor analysis. WAIS-IV-NL profiles of two clinical samples of 202 patients (i.e. patients with temporal lobe epilepsy and a mixed psychiatric outpatient group) were analyzed and contrasted with a matched control group (N = 202) selected from the Dutch standardization sample of the WAIS-IV-NL to investigate internal structure by means of CFA and BCCD. With CFA, the four-factor structure as proposed by Wechsler demonstrates acceptable fit in all three subsamples. However, BCCD revealed three consistent clusters (verbal comprehension, visual processing, and processing speed) in all three subsamples. The combination of Arithmetic and Digit Span as a coherent working memory factor could not be verified, and Matrix Reasoning appeared to be isolated. With BCCD, some discrepancies from the proposed four-factor structure are exemplified. Furthermore, these results fit CHC theory of intelligence more clearly. Consistent clustering patterns indicate these results are robust. The structural causal discovery approach may be helpful in better interpreting existing tests, the development of new tests, and aid in diagnostic instruments.

  14. Hydrogen segregation and its roles in structural stability and metallization: silane under pressure

    Science.gov (United States)

    Cui, Wenwen; Shi, Jingming; Liu, Hanyu; Yao, Yansun; Wang, Hui; Iitaka, Toshiaki; Ma, Yanming

    2015-08-01

    We present results from first-principles calculations on silane (SiH4) under pressure. We find that a three dimensional P-3 structure becomes the most stable phase above 241 GPa. A prominent structural feature, which separates the P-3 structure from previously observed/predicted SiH4 structures, is that a fraction of hydrogen leaves the Si-H bonding environment and forms segregated H2 units. The H2 units are sparsely populated in the system and intercalated with a polymeric Si-H framework. Calculations of enthalpy of formation suggest that the P-3 structure is against the decomposition into Si-H binaries and/or the elemental crystals. Structural stability of the P-3 structure is attributed to the electron-deficient multicenter Si-H-Si interactions when neighboring silicon atoms are linked together through a common hydrogen atom. Within the multicenter bonds, electrons are delocalized and this leads to a metallic state, possibly also a superconducting state, for SiH4. An interesting outcome of the present study is that the enthalpy sum of SiH4 (P-3 structure) and Si (fcc structure) appears to be lower than the enthalpy of disilane (Si2H6) between 200 and 300 GPa (for all previously predicted crystalline forms of Si2H6), which calls for a revisit of the stability of Si2H6 under high pressure.

  15. Experimental Adiabatic Quantum Factorization under Ambient Conditions Based on a Solid-State Single Spin System.

    Science.gov (United States)

    Xu, Kebiao; Xie, Tianyu; Li, Zhaokai; Xu, Xiangkun; Wang, Mengqi; Ye, Xiangyu; Kong, Fei; Geng, Jianpei; Duan, Changkui; Shi, Fazhan; Du, Jiangfeng

    2017-03-31

    The adiabatic quantum computation is a universal and robust method of quantum computing. In this architecture, the problem can be solved by adiabatically evolving the quantum processor from the ground state of a simple initial Hamiltonian to that of a final one, which encodes the solution of the problem. Adiabatic quantum computation has been proved to be a compatible candidate for scalable quantum computation. In this Letter, we report on the experimental realization of an adiabatic quantum algorithm on a single solid spin system under ambient conditions. All elements of adiabatic quantum computation, including initial state preparation, adiabatic evolution (simulated by optimal control), and final state read-out, are realized experimentally. As an example, we found the ground state of the problem Hamiltonian S_{z}I_{z} on our adiabatic quantum processor, which can be mapped to the factorization of 35 into its prime factors 5 and 7.

  16. Notch Sensitivity Factor Determination With Artificial Neural Network For Shafts Under The Bending Stress

    Directory of Open Access Journals (Sweden)

    Murat Tolga Özkan

    2013-01-01

    Full Text Available Notch, hole, tap and a variety of geometric shapes such as curves or discontinuities can be found with various reasons in the design of Machine Element. Stress is caused by sudden changes in section aggregating. Stress concentration can occur with the reason of material features of size or direction of forces application. This type of stress concentration in the material brings out the effect of notch. Notch impact can lead to distortions and breakage of materials. In this study, the notch sensitivity factor values have been modelled Artificial Neural Networks (ANN for shafts that is under the influence of bending stress, and the accuracy of the model has been verified by using Statistica software. The model has been developed using Pythia. With this software, the user can be obtained the accurate value by inputing shaft dimension and the applied force without the need for notch sensitivity factor tables and any calculations.

  17. Assessing adherence factors in patients under topical treatment: development of the Topical Therapy Adherence Questionnaire (TTAQ).

    Science.gov (United States)

    Zschocke, Ina; Mrowietz, Ulrich; Lotzin, Annett; Karakasili, Eleni; Reich, Kristian

    2014-04-01

    Medication adherence rates strongly depend on favorable disease outcomes. It is known that medication adherence rates are lower for topical treatment than for systemic treatment. However, to date no validated instrument for the assessment of adherence factors in topical treatment is available. The aim of this study was to develop a new questionnaire to assess adherence risk factors in topical treatment. The development of the Topical Therapy Adherence Questionnaire (TTAQ) and Patient Preference Questionnaire (PPQ) was based on a systematic literature review, and qualitative patient focus interviews and expert focus groups' input. The psychometric properties and comprehensibility of the TTAQ and PPQ were assessed in a feasibility study with 59 psoriasis patients. Our first preliminary results indicate that the TTAQ and PPQ are psychometrically sound and reliable measures for the assessment of factors influencing topical treatment adherence. The questionnaires are currently being further developed and various parameters (e.g., time point of assessment) are currently being tested in an exploratory pilot study with ca. 2,000 psoriasis patients receiving topical treatment in a European clinical trial. The use of the final versions of TTAQ and PPQ in clinical practice may facilitate the early identification of specific non-adherence factors in patients under topical treatment, which could enable designing and applying adherence-enhancing interventions according to the patient's individual needs.

  18. The effects of posterior cruciate ligament deficiency on posterolateral corner structures under gait- and squat-loading conditions

    Science.gov (United States)

    Kang, K-T.; Koh, Y-G.; Jung, M.; Nam, J-H.; Son, J.; Lee, Y.H.

    2017-01-01

    Objectives The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions. Methods A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered. Results Comparison of predicted passive flexion, posterior drawer kinematics and muscle activation with experimental measurements showed good agreement. Forces of the posterolateral corner structure, and TF and PF contact forces increased with PCL deficiency under gait- and squat-loading conditions. The rate of increase in PF contact force was the greatest during the squat-loading condition. The TF contact forces increased on both medial and lateral compartments during gait-loading conditions. However, during the squat-loading condition, the medial TF contact force tended to increase, while the lateral TF contact forces decreased. The posterolateral corner structure, which showed the greatest increase in force with deficiency of PCL under both gait- and squat-loading conditions, was the popliteus tendon (PT). Conclusion PCL deficiency is a factor affecting the variability of force on the PT in dynamic-loading conditions, and it could lead to degeneration of the PF joint. Cite this article: K-T. Kang, Y-G. Koh, M. Jung, J-H. Nam, J. Son, Y.H. Lee, S-J. Kim, S-H. Kim. The effects of posterior cruciate ligament deficiency on posterolateral corner structures under gait- and squat-loading conditions: A computational knee model. Bone Joint Res 2017;6:31–42. DOI: 10.1302/2046-3758.61.BJR-2016-0184.R1

  19. The deterministic structural integrity assessment of reactor pressure vessels under pressurized thermal shock loading

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mingya, E-mail: chenmingya@cgnpc.com.cn; Lu, Feng; Wang, Rongshan; Huang, Ping; Liu, Xiangbin; Zhang, Guodong; Xu, Chaoliang

    2015-07-15

    Highlights: • The conservative and non-conservative assumptions in the codes were shown. • The influence of different loads on the SM was given. • The unloading effect of the cladding was studied. • A concentrated reflection of the safety was shown based on 3-D FE analyses. - Abstract: The deterministic structural integrity of a reactor pressure vessel (RPV) related to pressurized thermal shocks (PTSs) has been extensively studied. While the nil-ductility-transition temperature (RT{sub NDT}) parameter is widely used, the influence of fluence and temperature distributions along the thickness of the base metal wall cannot be reflected in the comparative analysis. This paper introduces the method using a structure safety margin (SM) parameter which is based on a comparison between the material toughness (the fracture initiation toughness K{sub IC} or fracture arrest toughness K{sub Ia}) and the stress intensity factor (SIF) along the crack front for the integrity analysis of a RPV subjected to PTS transients. A 3-D finite element model is used to perform fracture mechanics analyses considering both crack initiation assessment and arrest assessment. The results show that the critical part along the crack front is always the clad-base metal interface point (IP) rather than the deepest point (DP) for either crack initiation assessment or crack arrest assessment under the thermal load. It is shown that the requirement in Regulatory Guide 1.154 that ‘axial flaws with depths less than 20% of the wall thickness and all circumferential flaws should be modeled in infinite length’ may be non-conservative. As the assessment result is often poor universal for a given material, crack and transient, caution is recommended in the safety assessment, especially for the IP. The SIF reduces under the thermal or pressure load if the map cracking (MC) effect is considered. Therefore, the assumption in the ASME and RCCM codes that the cladding should be taken into account in

  20. Factors impacting same-day cancellation of outpatient pediatric magnetic resonance imaging under anesthesia

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Andrea S. [University of Toronto, Department of Paediatrics, Division of Developmental Paediatrics, Holland Bloorview Kids Rehabilitation Hospital, Toronto (Canada); Matlow, Anne [University of Toronto, Strategic Initiatives, Postgraduate Medical Education, Toronto (Canada); Shroff, Manohar [University of Toronto, Department of Diagnostic Imaging, Division of Neuroradiology, Hospital for Sick Children, Toronto (Canada); Cohen, Eyal [University of Toronto, Division of Paediatric Medicine and Child Health Evaluative Sciences, Hospital for Sick Children, Department of Paediatrics and Institute of Health Policy, Management and Evaluation, Toronto (Canada)

    2014-07-24

    Studies of elective surgical procedures indicate that cancellation is common and preventable. Little is known about cancellation of anesthesia-supported elective diagnostic imaging. To describe the reasons for same-day cancellation of MRI studies performed under sedation or anesthesia and identify patient characteristics associated with cancellations. This case-control study was carried out in a university-affiliated tertiary care children's hospital. Cases were defined as elective outpatient MRI studies booked under anesthesia that were cancelled after the patient had arrived in the radiology department in 2009. Matched controls were identified by selecting the same day and time 1 week before or after the cancelled case. Main outcome measures included demographics, MRI study characteristics, and social and medical factors. There were 111 outpatient anesthesia-supported MRI studies cancelled on the same day as the assessment (cancellation rate: 4.5%), of which 74.6% were related to family and patient factors, while 22% were related to system factors. Cancelled cases involved patients who lived in lower median income quintile neighborhoods compared to controls (2 vs. 3; P = 0.0007; odds ratio [OR] 3.81; 95% confidence interval [CI] 1.18-12.34). Those who traveled a greater median distance (in kilometers) were less likely to be cancelled (18.8 vs. 27.1, P = 0.0035). Although cancelled patients had a lower mean number of total medical services (2.5 vs. 3.0; P = 0.03; OR = 0.78; 95% CI 0.62-0.98), current medical factors (past 12 months) did not impact cancellations. Same-day cancellations of anesthesia-supported MRI studies are not uncommon, and the main predictor of cancellation seems to be socioeconomic rather than medical. (orig.)

  1. Primary yield and multitranche structure in securitization issues: Explicative factors. A review

    Directory of Open Access Journals (Sweden)

    Miguel Á. Peña-Cerezo

    2016-09-01

    Full Text Available The reasons for the strong rise in the securitization phenomenon up until the start of the “subprime crisis” need to be analysed. According to many authors, they mainly stem from its offering the possibility of generating fixed yield securities with the highest rating and a low risk premium, thanks to the issues being structured in differentiated bond series, so that certain series absorb most of the risk, thus facilitating the safer or “senior” tranches having a higher rating. Accordingly, this paper reviews the literature on the factors underlying the generation of differentiated tranches in this type of issues and regarding the determining factors of the yield offered by securitization issues. It concludes that the search for more complete markets, along with the reducing of problems associated to the moral hazard, are the main reasons for the multi-tranche structuring. And given the strong influence of the number of tranches on the yield offered by the issues, the paper likewise concludes that the multitranche structures has been an efficient tool to place securitization issues with more competitive yields.

  2. PRIMARY YIELD AND MULTITRANCHE STRUCTURE IN SECURITIZATION ISSUES:EXPLICATIVE FACTORS. A REVIEW

    Directory of Open Access Journals (Sweden)

    Peña-Cerezo, Miguel A.

    2016-09-01

    Full Text Available The reasons for the strong rise in the securitization phenomenon up until the start of the subprime crisis need to be analysed. According to many authors, they mainly stem from its offering the possibility of generating fixed yield securities with the highest rating and a low risk premium, thanks to the issues being structured in differentiated bond series, so that certain series absorb most of the risk, thus facilitating the safer or senior tranches having a higher rating. Accordingly, this paper reviews the literature on the factors underlying the generation of differentiated tranches in this type of issues and regarding the determining factors ofthe yield offered by securitization issues. It concludes thatthe search for more complete markets, along with the reducing of problems associated to the moral hazard, are the main reasons for the multi-tranche structuring. And given the strong influence of the number of tranches on the yield offered by the issues, the paper likewise concludes that the multitranche structures has been an efficient tool to place securitization issues with more competitive yields.

  3. FACTORS INFLUENCING THERMAL STRUCTURE IN A TRIBUTARYBAY OF THREE GORGES RESERVOIR

    Institute of Scientific and Technical Information of China (English)

    YU Zhen-zhen; WANG Ling-ling

    2011-01-01

    To better understand the factors influencing the thermal structure of tributaries in the Three Gorges Reservoir(TGR),a well validated three-dimensional hydrodynamic and water temperature model was proposed to simulate the water temperature distribution in the Xiangxi Bay,a representative tributary of TGR.The numerical results show that water temperature stratification seasonally occurred in the Xiangxi Bay,with stable vertical temperature profiles.It is found from the numerical experiments that three key factors are responsible for the formation of water temperature structure:(1)very often,the locations of thermocline are mainly determined by wind speeds,and the higher the wind speed is,the deeper the thermocline is located beneath the water surface,which could be expressed by a fitted exponential function,(2)the thermal structure is affected by static stability of water column,and the thermocline becomes closer to the water surface and its thickness increases with the increase of temperature,(3)due to the effect of the thermal density inflow,the water temperature of the hypolimnion tends to be uniform,however,even under the condition of larger inflow discharge,the influence of the inflow on the epilimnion and the thermocline is not significant.

  4. Spatial heterogeneity and risk factors for stunting among children under age five in Ethiopia: A Bayesian geo-statistical model

    Science.gov (United States)

    Hagos, Seifu; Hailemariam, Damen; WoldeHanna, Tasew; Lindtjørn, Bernt

    2017-01-01

    Background Understanding the spatial distribution of stunting and underlying factors operating at meso-scale is of paramount importance for intervention designing and implementations. Yet, little is known about the spatial distribution of stunting and some discrepancies are documented on the relative importance of reported risk factors. Therefore, the present study aims at exploring the spatial distribution of stunting at meso- (district) scale, and evaluates the effect of spatial dependency on the identification of risk factors and their relative contribution to the occurrence of stunting and severe stunting in a rural area of Ethiopia. Methods A community based cross sectional study was conducted to measure the occurrence of stunting and severe stunting among children aged 0–59 months. Additionally, we collected relevant information on anthropometric measures, dietary habits, parent and child-related demographic and socio-economic status. Latitude and longitude of surveyed households were also recorded. Local Anselin Moran's I was calculated to investigate the spatial variation of stunting prevalence and identify potential local pockets (hotspots) of high prevalence. Finally, we employed a Bayesian geo-statistical model, which accounted for spatial dependency structure in the data, to identify potential risk factors for stunting in the study area. Results Overall, the prevalence of stunting and severe stunting in the district was 43.7% [95%CI: 40.9, 46.4] and 21.3% [95%CI: 19.5, 23.3] respectively. We identified statistically significant clusters of high prevalence of stunting (hotspots) in the eastern part of the district and clusters of low prevalence (cold spots) in the western. We found out that the inclusion of spatial structure of the data into the Bayesian model has shown to improve the fit for stunting model. The Bayesian geo-statistical model indicated that the risk of stunting increased as the child’s age increased (OR 4.74; 95% Bayesian credible

  5. Reliability-based service life prediction of existing concrete structures under marine environment

    Institute of Scientific and Technical Information of China (English)

    吴灵杰; 周拥军; 寇新建; 蒋萌

    2015-01-01

    Chloride-induced corrosion of the reinforcement is considered as one of the major mechanisms resulting in the reduction of structural resistance of reinforced concrete structural elements located in marine and other aggressive environments. A study of reinforced concrete structures located at the Fangcheng dock in the Beibu Gulf port, China, was present. The result from field survey indicates that the concrete cover depth and chloride diffusion coefficient fit best normal distribution and lognormal distribution, respectively. The service life of structure is about 55 a, while initiation time is 45 a. Sensitivity analysis indicates that the most influential factor of the structure service life prediction is concrete cover, followed by diffusion coefficient, diffusion decay index, critical chloride concentration, surface chloride concentration, current density and localized pitting corrosion. Finally, the effects of diffusion decay index and critical chloride concentration on structure service life prediction are discussed.

  6. First-principles study of structural stabilities of AlH3 under high pressure

    Science.gov (United States)

    Feng, Wenxia; Cui, Shouxin; Feng, Min

    2014-07-01

    The structural stabilities and electronic properties of AlH3 under high pressure are investigated by using the plane-wave pseudopotential method. Our results demonstrate that the sequence of the pressure-induced phase transition is Fd 3 bar m(β) → cmcm(α ') → R 3 bar c(α) → Pnma(hp 1) → Pm 3 bar n(hp 2), and the transition pressures are 0.49, 0.91, 47, and 70 GPa, respectively. Im 3 bar m , Pnnm(γ) and P63/m structures are not stable in the 0-100 GPa. β, α ', α, and hp1 structures of AlH3 are nonmetals, while Pm 3 bar n structure of AlH3 is metallic, and the pressure-induced metallization is ascribed to phase transition under higher compression.

  7. Risk factors for hearing loss in infants under universal hearing screening program in Northern Thailand

    Directory of Open Access Journals (Sweden)

    Poonual W

    2015-12-01

    Full Text Available Watcharapol Poonual,1 Niramon Navacharoen,2 Jaran Kangsanarak,2 Sirianong Namwongprom3 1Clinical Epidemiology Program, 2Department of Otolaryngology, 3Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand Objective: To define the risk factors for hearing loss in infants (aged 3 months under universal hearing screening program. Materials and methods: A total of 3,120 infants (aged 3 months who underwent hearing screening using a universal hearing screening program using automated otoacoustic emission test between November 1, 2010 and May 31, 2012 in Uttaradit Hospital, Buddhachinaraj Hospital, and Sawanpracharuk Hospital (tertiary hospitals located in Northern Thailand were included in this prospective cohort study. Results: Of the 3,120 infants, 135 (4.3% were confirmed to have hearing loss with the conventional otoacoustic emission test. Five of these 135 infants (3.7% with hearing loss showed test results consistent with auditory brainstem responses. From the univariable analysis, there were eleven potential risk factors associated with hearing deterioration. On multivariable analysis, the risk factors independently associated with hearing loss at 3 months were birth weight 1,500–2,500 g (risk ratio [RR] 1.6, 95% confidence interval [CI] 1.1–2.6, APGAR score <6 at 5 minutes (RR 2.2, 95% CI 1.1–4.4, craniofacial anomalies (RR 2.5, 95% CI 1.6–4.2, sepsis (RR 1.8, 95% CI 1.0–3.2, and ototoxic exposure (RR 4.1, 95% CI 1.9–8.6. Conclusion: This study concluded that low birth weight, APGAR score <6 at 5 minutes, craniofacial anomalies, sepsis, and ototoxic exposure are the risk factors for bilateral hearing loss in infants (aged 3 months and proper tests should be performed to identify these risk factors. As an outcome, under the present circumstances, it is suggested that infirmary/physicians/general practitioners/health action centers/polyclinics should carry out universal hearing screening in all

  8. Experimental study of critical heat flux enhancement with hypervapotron structure under natural circulation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Fangxin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); Chang, Huajian [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Zhao, Yufeng, E-mail: zhaoyufeng@snptc.com.cn [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Zhang, Ming; Gao, Tianfang [State Nuclear Power Technology R& D Center (Beijing), Beijing (China); Chen, Peipei [State Power Investment Corporation, Beijing (China)

    2017-05-15

    Highlights: • Natural circulation tests are performed to study the effect of hypervapotron on CHF. • Hypervapotron structure improves CHF under natural circulation conditions. • Visualization data illustrate vapor blanket behavior under subcooled flow conditions. - Abstract: The enhancement of critical heat flux with a hypervapotron structure under natural circulation conditions is investigated in this study. Subcooled flow boiling CHF experiments are performed using smooth and hypervapotron surfaces at different inclination angles under natural circulation conditions. The experimental facility, TESEC (Test of External Vessel Surface with Enhanced Cooling), is designed to conduct CHF experiments in a 30 mm by 61 mm rectangular flow channel with a 200 mm long heated surface along the flow direction. The two-phase flow of subcooled flow boiling on both smooth and hypervapotron heating plates is observed and analyzed by the high-speed visualization technology. The results show that both smooth surface and hypervapotron surface CHF data exhibit a similar trend against inclination angles compared with the CHF results under forced flow condition on the same facility in earlier studies. However, the CHF enhancement of the hypervapotron structure is evidently more significant than the one under forced flow conditions. The experiments also indicate that the natural flow rates are higher with hypervapotron structure. The initiation of CHF is analyzed under transient subcooling and flow rate conditions for both smooth and hypervapotron heating surfaces. An explanation is given for the significant enhancement effect caused by the hypervapotron surface under natural circulation conditions. The visualization data are exhibited to demonstrate the behavior of the vapor blanket at various inclination angles and on different surfaces. The geometric data of the vapor blanket are quantified by an image post-processing method. It is found that the thickness of the vapor blanket

  9. Probing the local, electronic and magnetic structure of matter under extreme conditions of temperature and pressure

    DEFF Research Database (Denmark)

    Torchio, R.; Boccato, S.; Cerantola, V.;

    2016-01-01

    In this paper we present recent achievements in the field of investigation of the local, electronic and magnetic structure of the matter under extreme conditions of pressure and temperature. These results were obtained thanks to the coupling of a compact laser heating system to the energy......-dispersive XAS technique available on the ID24 beamline at the ESRF synchrotron. The examples chosen concern the melting and the liquid structure of 3d metals and alloys under high pressures (HPs) and the observation of temperature-induced spin crossover in FeCO3 at HP....

  10. Structural Rearrangement of Au-Pd Nanoparticles under Reaction Conditions: An ab Initio Molecular Dynamics Study.

    Science.gov (United States)

    Xu, Cong-Qiao; Lee, Mal-Soon; Wang, Yang-Gang; Cantu, David C; Li, Jun; Glezakou, Vassiliki-Alexandra; Rousseau, Roger

    2017-02-28

    The structure, composition, and atomic distribution of nanoalloys under operating conditions are of significant importance for their catalytic activity. In the present work, we use ab initio molecular dynamics simulations to understand the structural behavior of Au-Pd nanoalloys supported on rutile TiO2 under different conditions. We find that the Au-Pd structure is strongly dependent on the redox properties of the support, originating from strong metal-support interactions. Under reducing conditions, Pd atoms are inclined to move toward the metal/oxide interface, as indicated by a significant increase of Pd-Ti bonds. This could be attributed to the charge localization at the interface that leads to Coulomb attractions to positively charged Pd atoms. In contrast, under oxidizing conditions, Pd atoms would rather stay inside or on the exterior of the nanoparticle. Moreover, Pd atoms on the alloy surface can be stabilized by hydrogen adsorption, forming Pd-H bonds, which are stronger than Au-H bonds. Our work offers critical insights into the structure and redox properties of Au-Pd nanoalloy catalysts under working conditions.

  11. Phase stability and structural distortion of NiO under high pressure

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-bing; HU Yu-lin; TANG Bi-yu

    2006-01-01

    The phase stability and structural distortion of NiO under high pressure were investigated using first-principles calculations based on density-functional theory. Different forms of exchange-correlation functional including LDA,GGA and GGA+U were used in the present calculations. All of the three methods predict NiO to be AFM II ordering with the cell slightly compressed along [111] direction and also indicate that there is no structural phase transition of NiO under pressure up to 140 GPa,which are in agreement with the experiment. However,both LDA and GGA incorrectly predict the structural distortion under pressure especially above 60 GPa. Only when strong correlations are included in form of GGA+U,structural distortion under high pressure can qualitatively agree with the experiment. The related mechanism was also analyzed and discussed. These results suggest that the strong electronic correlations still play a very important role in the properties of NiO under high pressure.

  12. Higher order factor structure of the WISC-IV in a clinical neuropsychological sample.

    Science.gov (United States)

    Bodin, Doug; Pardini, Dustin A; Burns, Thomas G; Stevens, Abigail B

    2009-09-01

    A confirmatory factor analysis was conducted examining the higher order factor structure of the WISC-IV scores for 344 children who participated in neuropsychological evaluations at a large children's hospital. The WISC-IV factor structure mirrored that of the standardization sample. The second order general intelligence factor (g) accounted for the largest proportion of variance in the first-order latent factors and in the individual subtests, especially for the working memory index. The first-order processing speed factor exhibited the most unique variance beyond the influence of g. The results suggest that clinicians should not ignore the contribution of g when interpreting the first-order factors.

  13. Structural changes and degradation of Red Latosols under different management systems for 20 years

    Directory of Open Access Journals (Sweden)

    João Tavares Filho

    2014-08-01

    Full Text Available Soils are the foundation of terrestrial ecosystems and their role in food production is fundamental, although physical degradation has been observed in recent years, caused by different cultural practices that modify structures and consequently the functioning of soils. The objective of this study was to evaluate possible structural changes and degradation in an Oxisol under different managements for 20 years: no-tillage cultivation with and without crop rotation, perennial crop and conventional tillage, plus a forested area (reference. Initially, the crop profile was described and subsequently, 10 samples per management system and forest soil were collected to quantify soil organic matter, flocculation degree, bulk density, and macroporosity. The results indicated structural changes down to a soil depth of 50 cm, with predominance of structural units ∆μ (intermediate compaction level under perennial crop and no-tillage crop rotation, and of structural units ∆ (compacted under conventional tillage and no-tillage. The soil was increasingly degraded in the increasing order: forest => no-tillage crop rotation => perennial crop => no-tillage without crop rotation => conventional tillage. In all managements, the values of organic matter and macroporosity were always below and bulk density always above those of the reference area (forest and, under no-tillage crop rotation and perennial crop, the flocculation degree was proportionally equal to that of the reference area.

  14. Risk factors for under-5 mortality: evidence from Bangladesh Demographic and Health Survey, 2004-2011.

    Science.gov (United States)

    Abir, Tanvir; Agho, Kingsley Emwinyore; Page, Andrew Nicolas; Milton, Abul Hasnat; Dibley, Michael John

    2015-08-21

    The aim of this study was to identify factors associated with mortality in children under 5 years of age using a nationally representative sample of singleton births for the period of 2004-2011. Pooled 2004, 2007 and 2011 cross-sectional data sets of the Bangladesh Demographic and Health Surveys were analysed. The surveys used a stratified two-stage cluster sample of 16,722 singleton live-born infants of the most recent birth of a mother within a 3-year period. Outcome measures were neonatal mortality (0-30 days), postneonatal mortality (1-11 months), infant mortality (0-11 months), child mortality (1-4 years) and under-5 mortality (0-4 years). Survival information for 16,722 singleton live-born infants and 522 deaths of children child deaths and 522 under-5 deaths. Multiple variable analysis showed that, over a 7-year period, mortality reduced significantly by 48% for postneonatal deaths, 33% for infant deaths and 29% for under-5 deaths, but there was no significant reduction in neonatal deaths (adjusted OR (AOR) = 0.79, 95% CI 0.59 to 1.06) or child deaths (AOR = 1.00, 95% CI 0.51 to 1.94). The odds of neonatal, postneonatal, infant, child and under-5 deaths decreased significantly among mothers who used contraceptive and mothers who had other children aged 3 years or older. The risk of neonatal, postneonatal, infant, child and under-5 deaths was significantly higher in mothers who reported a previous death of a sibling. Our study suggests that family planning is needed to further reduce the overall rate of under-5 deaths in Bangladesh. To reduce childhood mortality, public health interventions that focus on child spacing and contraceptive use by mothers may be most effective. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. 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

    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...

  16. A Two-step Approach to Progressive Collapse Analysis of Building Structures under Blast Loading

    Institute of Scientific and Technical Information of China (English)

    XU Jun-xian; LIU Xi-la

    2009-01-01

    Structural collapse under blast loads is a very complex process. For several decades, the engineering profession has considered some approaches to analyze the essential physics of collapse phenomena. Recently, the interest in this topic has risen to an apex since the collapse of the World Trade Center towers. A two-step analysis approach to capture the characteristics of structural collapse during explosions is proposed. A numerical example is presented to illustrate the performance of the presented approach.

  17. Crystal structure of the DNA-binding domain of Myelin-gene Regulatory Factor.

    Science.gov (United States)

    Zhen, Xiangkai; Li, Bowen; Hu, Fen; Yan, Shufeng; Meloni, Gabriele; Li, Huiliang; Shi, Ning

    2017-06-16

    Myelin-gene Regulatory Factor (MyRF) is one of the master transcription factors controlling myelin formation and development in oligodendrocytes which is crucial for the powerful brain functions. The N-terminal of MyRF, which contains a proline-rich region and a DNA binding domain (DBD), is auto-cleaved from the ER membrane, and then enters the nucleus to participate in transcription regulation of the myelin genes. Here we report the crystal structure of MyRF DBD. It shows an Ig-fold like architecture which consists of two antiparallel β-sheets with 7 main strands, packing against each other, forming a β-sandwich. Compared to its homolog, Ndt80, MyRF has a smaller and less complex DBD lacking the helices and the big loops outside the core. Structural alignment reveals that MyRF DBD possess less interaction sites with DNA than Ndt80 and may bind only at the major groove of DNA. Moreover, the structure reveals a trimeric assembly, agreeing with the previous report that MyRF DBD functions as a trimer. The mutant that we designed based on the structure disturbed trimer formation, but didn't affect the auto-cleavage reaction. It demonstrates that the activation of self-cleavage reaction of MyRF is independent of the presence of its N-terminal DBD homotrimer. The structure reported here will help to understand the molecular mechanism underlying the important roles of MyRF in myelin formation and development.

  18. Factor structure of the Private Self-Consciousness Scale.

    Science.gov (United States)

    Anderson, E M; Bohon, L M; Berrigan, L P

    1996-02-01

    Several issues concerning the factors of the Private Self-Consciousness Scale (PRSC) of Fenigstein et al. (1975) are examined, including possible artifactuality and appropriate conceptualization. Findings confirm the existence of the 2 factors reported in previous research (Burnkrant & Page, 1984; Lennox, Welch, Wolfe, Zimmerman, & Dixon, 1987; Mittal & Balasubramanian, 1987; Piliavin & Charng, 1988) and suggest that these factors are substantive, not artifactual, in nature. One factor was found to be associated with mild levels of psychopathology, whereas the other was not. In addition to providing a clearer conception of the nature of these factors, our results may help to resolve apparently contradictory findings in the PRSC literature. Implications for research on self-focused attention are also discussed.

  19. Factors limiting endurance of armor, artillery, and infantry units under simulated NBC conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, T.M.; Tharion, W.J.; Banderet, L.E.; Lussier, A.R.

    1986-03-13

    The war of the future will require 72-hour operations in environments contaminated with nuclear/biological/chemical (NBC) agents. The 1985 P2NBC2 (Physiological and Psychological Effects of NBC and Extended Operations on Combined Arms Crews) Program assessed soldier endurance and performance under simulated NBC conditions. A total of 175 soldiers were observed during four tests differing in design, site, climatic conditions, and performance demands. In all but one of the iterations where the full chemical-protective ensemble (MOPP 4) was used without cooling, soldier endurance fell far short of the projected requirement. Psychological data were analyzed to determine which factors were associated with the incidence of casualties. The findings showed that perceived intensity of symptoms resembling the hyperventilation syndrome was significantly greater in soldiers classified as Casualties. Five of these symptoms (painful breathing, difficulty breathing, shortness of breath, headache, and nausea) showed Casualty-Survivor differences in all tests. Symptom intensity was attributed to two factors. (1) External conditions. Thermal stress exacerbated the five basic symptoms, induced others (tetany and paresthesia), and decreased endurance. Periodic relief from respirator use attenuated these symptoms and enhanced endurance. (2) Individual differences. Significant Casualty-Survivor differences in anxiety, depression, and cognitive strategy scores indicated that perception of hyperventilation symptoms and endurance were related to personality variables. Hyperventilation symptoms could incapacitate the soldier or induce removal of the protective mask under actual chemical attack.

  20. Oxygen Consumption by Postfermentation Wine Yeast Lees: Factors Affecting Its Rate and Extent under Oenological Conditions

    Directory of Open Access Journals (Sweden)

    Jonas Müller

    2016-01-01

    Full Text Available Postfermentation wine yeast lees show antioxidant properties based on their ability to consume dissolved oxygen. The oxygen consumption capacity of suspended yeast lees obtained after fermentations with six commercial active dry yeast strains was investigated in model, white and red wines using fluorescence-based oxygen sensors operating in a nondestructive way. In model solution, the oxygen consumption rate of yeast lees was shown to depend on their amount, yeast strain, sulfur dioxide and temperature. It is slightly lower in red than in white wines. It is strongly decreased by current levels of free sulfur dioxide, thus excluding the complementary use of both as antioxidants in wine. However, in 25 randomly sampled white wines produced under commercial conditions, the rate and extent of oxygen consumption during the first six months of postfermentation had no significant correlation with any of these interacting factors, making it difficult to predict the actual antioxidant effect of yeast lees. In these wines, yeast lees consumed 0 to 47 % of the dissolved oxygen. Although total oxygen consumption capacity of yeast lees is not a limiting factor under commercial winemaking conditions, their oxygen consumption proceeds at a limited rate that reduces but cannot totally prevent concomitant chemical oxidation of the wine.

  1. Oxygen Consumption by Postfermentation Wine Yeast Lees: Factors Affecting Its Rate and Extent under Oenological Conditions

    Science.gov (United States)

    Müller, Jonas; Schmidt, Dominik

    2016-01-01

    Summary Postfermentation wine yeast lees show antioxidant properties based on their ability to consume dissolved oxygen. The oxygen consumption capacity of suspended yeast lees obtained after fermentations with six commercial active dry yeast strains was investigated in model, white and red wines using fluorescence-based oxygen sensors operating in a nondestructive way. In model solution, the oxygen consumption rate of yeast lees was shown to depend on their amount, yeast strain, sulfur dioxide and temperature. It is slightly lower in red than in white wines. It is strongly decreased by current levels of free sulfur dioxide, thus excluding the complementary use of both as antioxidants in wine. However, in 25 randomly sampled white wines produced under commercial conditions, the rate and extent of oxygen consumption during the first six months of postfermentation had no significant correlation with any of these interacting factors, making it difficult to predict the actual antioxidant effect of yeast lees. In these wines, yeast lees consumed 0 to 47% of the dissolved oxygen. Although total oxygen consumption capacity of yeast lees is not a limiting factor under commercial winemaking conditions, their oxygen consumption proceeds at a limited rate that reduces but cannot totally prevent concomitant chemical oxidation of the wine. PMID:28115896

  2. Dimensions Underlying Measures of Disability, Personal Factors, and Health Status in Cervical Radiculopathy

    Science.gov (United States)

    Halvorsen, Marie; Kierkegaard, Marie; Harms-Ringdahl, Karin; Peolsson, Anneli; Dedering, Åsa

    2015-01-01

    Abstract This cross-sectional study sought to identify dimensions underlying measures of impairment, disability, personal factors, and health status in patients with cervical radiculopathy. One hundred twenty-four patients with magnetic resonance imaging-verified cervical radiculopathy, attending a neurosurgery clinic in Sweden, participated. Data from clinical tests and questionnaires on disability, personal factors, and health status were used in a principal-component analysis (PCA) with oblique rotation. The PCA supported a 3-component model including 14 variables from clinical tests and questionnaires, accounting for 73% of the cumulative percentage. The first component, pain and disability, explained 56%. The second component, health, fear-avoidance beliefs, kinesiophobia, and self-efficacy, explained 9.2%. The third component including anxiety, depression, and catastrophizing explained 7.6%. The strongest-loading variables of each dimension were “present neck pain intensity,” “fear avoidance,” and “anxiety.” The three underlying dimensions identified and labeled Pain and functioning, Health, beliefs, and kinesiophobia, and Mood state and catastrophizing captured aspects of importance for cervical radiculopathy. Since the variables “present neck pain intensity,” “fear avoidance,” and “anxiety” had the strongest loading in each of the three dimensions; it may be important to include them in a reduced multidimensional measurement set in cervical radiculopathy. PMID:26091482

  3. Factors influencing mothers' role in convulsion treatment among under-five children in Ibadan, Nigeria.

    Science.gov (United States)

    Nwokocha, Ezenwa E; Awomoyi, Aanuoluwayomi O

    2009-01-01

    Convulsion among children between six months and five years is a major contributor to childhood mortality in less-developed societies, especially in sub-Saharan Africa. Most studies on under-five deaths have ignored the influence of socio-demographic and environmental factors as they relate to causes of the thematic health condition and available therapies. This study investigated mothers' perception of convulsion causation, relevant signs and symptoms, and the influence of socio-economic status on mothers' choice of remedies. The research was conducted in Ibadan, southwest Nigeria, which is densely populated with mainly Yoruba-speaking people. The study population comprised mothers who, at the time of fieldwork for the present analysis, had at least one under-five child. Five hundred questionnaire respondents were selected through a multistage sampling technique, and 14 in-depth interviews (IDIs) were conducted among different categories of women identified through the snowball technique. Voluntary Social Action Theory and the Health Belief Model were used in explaining the relationship between the dependent and independent variables. The findings show that the remedies mothers chose were strongly influenced by socio-demographic factors such as marriage type, religion, level of education, occupation and place of residence. It is strongly suggested that interventions, health policies and programs should focus on how best to empower women to effectively utilize medical information that will enable them recognize symptoms of this common health condition and/or undertake preliminary therapies that contribute positively to convulsion prevention or treatment.

  4. Time-dependent confidence factor for structures with degradation caused by fatigue

    Directory of Open Access Journals (Sweden)

    Ruiz-Gómez Sonia E.

    2014-07-01

    Full Text Available An approach to evaluate the confidence factor for structures at the end of an interval of time is proposed. The confidence factor indicates the adequacy of the performance level of a structure subjected to external loads. The factor considers the uncertainties implicit in the structural capacity and in the structural demand. The formulation is made in accordance with the Demand and Capacity Factor Design Format. Four scenarios are compared: a structural capacity deteriorates over a time interval, while structural demand remains constant, b only structural demand (for a given intensity varies in time, c both structural capacity and structural demand vary simultaneously in time, and d the effect of structural deterioration is neglected. The approach is applied to an offshore jacket platform. Deterioration is taken into account by analyzing the growth of fatigue cracks in both ends of several critical structural elements. It is concluded that for the evaluation of the confidence factor over an interval of interest, for the case analyzed, it is more significant to consider the variation in time of the structural capacity rather than that of the structural demand; however, it is recommended to consider both (structural capacity and structural demand in the analysis.

  5. Simultaneous Bayesian estimation of alignment and phylogeny under a joint model of protein sequence and structure.

    Science.gov (United States)

    Herman, Joseph L; Challis, Christopher J; Novák, Ádám; Hein, Jotun; Schmidler, Scott C

    2014-09-01

    For sequences that are highly divergent, there is often insufficient information to infer accurate alignments, and phylogenetic uncertainty may be high. One way to address this issue is to make use of protein structural information, since structures generally diverge more slowly than sequences. In this work, we extend a recently developed stochastic model of pairwise structural evolution to multiple structures on a tree, analytically integrating over ancestral structures to permit efficient likelihood computations under the resulting joint sequence-structure model. We observe that the inclusion of structural information significantly reduces alignment and topology uncertainty, and reduces the number of topology and alignment errors in cases where the true trees and alignments are known. In some cases, the inclusion of structure results in changes to the consensus topology, indicating that structure may contain additional information beyond that which can be obtained from sequences. We use the model to investigate the order of divergence of cytoglobins, myoglobins, and hemoglobins and observe a stabilization of phylogenetic inference: although a sequence-based inference assigns significant posterior probability to several different topologies, the structural model strongly favors one of these over the others and is more robust to the choice of data set.

  6. Factors related to the capital structure of small new ventures

    NARCIS (Netherlands)

    Harms, Rainer; Breitenecker, R.; Schwartz, E.J.; Wdowiak, M.A.

    2012-01-01

    In the literature, there exists evidence on the capital structure determinants for small ventures, but empirical research for new ventures is limited. We seek to address this gap by presenting a confirmatory analysis of determinants of capital structure of a sample of small new ventures in Austria.

  7. Further evidence of psychological factors underlying choice of elective cesarean delivery (ECD) by primigravidae.

    Science.gov (United States)

    Matinnia, Nasrin; Haghighi, Mohammad; Jahangard, Leila; Ibrahim, Faisal B; Rahman, Hejar A; Ghaleiha, Ali; Holsboer-Trachsler, Edith; Brand, Serge

    2017-06-12

    Requests for elective cesarean delivery (ECD) have increased in Iran. While some sociodemographic and fear-related factors have been linked with this choice, psychological factors such as self-esteem, stress, and health beliefs are under-researched. A total of 342 primigravidae (mean age = 25 years) completed questionnaires covering psychological dimensions such as self-esteem, perceived stress, marital relationship quality, perceived social support, and relevant health-related beliefs. Of the sample, 214 (62.6%) chose to undergo ECD rather than vaginal delivery (VD). This choice was associated with lower self-esteem, greater perceived stress, belief in higher susceptibility to problematic birth and barriers to an easy birth, along with lower perceived severity of ECD, fewer perceived benefits from VD, lower self-efficacy and a lower feeling of preparedness. No differences were found for marital relationship quality or perceived social support. The pattern suggests that various psychological factors such as self-esteem, self-efficacy, and perceived stress underpin the decision by primigravidae to have an ECD.

  8. You Want Me to Use THAT Robot? Identifying Underlying Factors Affecting Robot Use

    Science.gov (United States)

    Yagoda, Rosemarie Elaine

    Building on traditional technology acceptance and human-robot interaction (HRI) research, this research sought to investigate operational HRI factors affecting robot use within the context of a high-risk environment. Technology acceptance models have previously focused on perceived usefulness and ease of use, but have tended to ignore barriers or external factors associated with technology adoption. The present studies investigate the role of barriers such as operational risk and lack of HRI trust in determining acceptance of robots. Experiment 1 empirically refined the experimental methodology used in Experiment 2 to investigate factors affecting robot use. Overall, the results highlighted the influence of HRI trust and operational risk on the likelihood of robot use; in addition, they shed light on the importance of the configuration of the robot capabilities needed for task completion. With the proposition that these relationships were moderated by the robot configuration, HRI trust was shown to increase the overall likelihood of robot use and only slight variations were attributed to increased operational risk. HRI trust was shown to have both a positive and negative influence in terms of the operational risks associated with on robot use. In fact, instances when HRI trust is high may lead to using a robot that is not even properly configured for the high-risk task. Therefore, it is beneficial to understand the underlying mechanisms that influence the perception (right or wrong) surrounding unmanned systems. The findings from this research can be used to enhance the utility and acceptance of new or existing unmanned systems.

  9. Acoustic and Vibration Control for an Underwater Structure under Mechanical Excitation

    Directory of Open Access Journals (Sweden)

    Shi-Jian Zhu

    2014-01-01

    Full Text Available Acoustic and vibration control for an underwater structure under mechanical excitation has been investigated by using negative feedback control algorithm. The underwater structure is modeled with cylindrical shells, conical shells, and circular bulkheads, of which the motion equations are built with the variational approach, respectively. Acoustic property is analyzed by the Helmholtz integration formulation with boundary element method. Based on negative feedback control algorithm, a control loop with a coupling use of piezoelectric sensor and actuator is built, and accordingly some numerical examples are carried out on active control of structural vibration and acoustic response. Effects of geometrical and material parameters on acoustic and vibration properties are investigated and discussed.

  10. Formation and evolution of tweed structures on high-purity aluminum polycrystalline foils under cyclic tension

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, P. V., E-mail: kpv@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Vlasov, I. V. [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Sklyarova, E. A.; Smekalina, T. V. [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2015-10-27

    Peculiarities of formation and evolution of tweed structures on the surface of high-purity aluminum polycrystalline foils under cyclic tension were studied using an atom force microscope and a white light interferometer. Tweed structures of micron and submicron sizes were found on the foils at different number of cycles. In the range of 42,000 < N < 95,000 cycles destruction of tweed patterns is observed, which leads to their disappearance from the surface of the foils. Formation of tweed structures of various scales is discussed in terms of the Grinfeld instability.

  11. Formation and evolution of tweed structures on high-purity aluminum polycrystalline foils under cyclic tension

    Science.gov (United States)

    Kuznetsov, P. V.; Vlasov, I. V.; Sklyarova, E. A.; Smekalina, T. V.

    2015-10-01

    Peculiarities of formation and evolution of tweed structures on the surface of high-purity aluminum polycrystalline foils under cyclic tension were studied using an atom force microscope and a white light interferometer. Tweed structures of micron and submicron sizes were found on the foils at different number of cycles. In the range of 42,000 < N < 95,000 cycles destruction of tweed patterns is observed, which leads to their disappearance from the surface of the foils. Formation of tweed structures of various scales is discussed in terms of the Grinfeld instability.

  12. Structural Changes of International Trade Flows under the Impact of Globalization

    Directory of Open Access Journals (Sweden)

    Anca Dachin

    2006-08-01

    Full Text Available Structural changes of international trade flows indicate modifications in competitiveness of countries, in terms of production, technological upgrading and exports under the pressure of globalization. The paper aims to point out sources of competitive advantages especially in manufacturing exports of different groups of countries. The focus is on the shifts in the structure of manufacturing in the European Union and their effects on international rankings in export performances. An important issue refers to the opportunities given by the enlargement of the European Union and their impact on EU trade structures.

  13. Atomic-Scale Observations of Catalyst Structures under Reaction Conditions and during Catalysis.

    Science.gov (United States)

    Tao, Franklin Feng; Crozier, Peter A

    2016-03-23

    Heterogeneous catalysis is a chemical process performed at a solid-gas or solid-liquid interface. Direct participation of catalyst atoms in this chemical process determines the significance of the surface structure of a catalyst in a fundamental understanding of such a chemical process at a molecular level. High-pressure scanning tunneling microscopy (HP-STM) and environmental transmission electron microscopy (ETEM) have been used to observe catalyst structure in the last few decades. In this review, instrumentation for the two in situ/operando techniques and scientific findings on catalyst structures under reaction conditions and during catalysis are discussed with the following objectives: (1) to present the fundamental aspects of in situ/operando studies of catalysts; (2) to interpret the observed restructurings of catalyst and evolution of catalyst structures; (3) to explore how HP-STM and ETEM can be synergistically used to reveal structural details under reaction conditions and during catalysis; and (4) to discuss the future challenges and prospects of atomic-scale observation of catalysts in understanding of heterogeneous catalysis. This Review focuses on the development of HP-STM and ETEM, the in situ/operando characterizations of catalyst structures with them, and the integration of the two structural analytical techniques for fundamentally understanding catalysis.

  14. Study on Influencing Factors of Capital Structure of Energy Listed Companies

    Institute of Scientific and Technical Information of China (English)

    HUANG Guo-liang; LI Qiang

    2005-01-01

    Based on the determinative factors school of capital structure theory, this paper uses the data of 35 Chinese energy listed companies from 2000 to 2003, and adopts multi-variable regression method to make an empirical study of the influencing factors of their capital structure. The results indicate that the factors of size, income volatility, and the concentration of owner's equity have positive relation with the capital structure, while the relation between profitability and capital structure is negative. It is also found that the influencing of growth and secured asset on the capital structure are relatively insignificant.

  15. Seismic Responses of Asymmetric Base-Isolated Structures under Near-Fault Ground Motion

    Institute of Scientific and Technical Information of China (English)

    YE Kun; LI Li; FANG Qin-han

    2008-01-01

    An inter-story shear model of asymmetric base-isolated structures incorporating deformation of each isolation bearing was built, and a method to simultaneously simulate bi-directional near-fault and far-field ground motions was proposed. A comparative study on the dynamic responses of asymmetric base-isolated structures under near-fault and far-field ground motions were conducted to investigate the effects of eccentricity in the isolation system and in the superstructures, the ratio of the uncoupled torsional to lateral frequency of the superstructure and the pulse period of near-fault ground motions on the nonlinear seismic response of asymmetric base-isolated structures. Numerical results show that eccentricity in the isolation system makes asymmetric base-isolated structure more sensitive to near-fault ground motions, and the pulse period of near-fault ground motions plays an import role in governing the seismic responses of asymmetric base-isolated structures.

  16. Optimal Shakedown of the Thin-Wall Metal Structures Under Strength and Stiffness Constraints

    Directory of Open Access Journals (Sweden)

    Alawdin Piotr

    2017-06-01

    Full Text Available Classical optimization problems of metal structures confined mainly with 1st class cross-sections. But in practice it is common to use the cross-sections of higher classes. In this paper, a new mathematical model for described shakedown optimization problem for metal structures, which elements are designed from 1st to 4th class cross-sections, under variable quasi-static loads is presented. The features of limited plastic redistribution of forces in the structure with thin-walled elements there are taken into account. Authors assume the elastic-plastic flexural buckling in one plane without lateral torsional buckling behavior of members. Design formulae for Methods 1 and 2 for members are analyzed. Structures stiffness constrains are also incorporated in order to satisfy the limit serviceability state requirements. With the help of mathematical programming theory and extreme principles the structure optimization algorithm is developed and justified with the numerical experiment for the metal plane frames.

  17. Empirical study on structural properties in temporal networks under different time scales

    Science.gov (United States)

    Chen, Duanbing

    2015-12-01

    Many network analyzing methods are usually based on static networks. However, temporal networks should be considered so as to investigate real complex systems deeply since some dynamics on these systems cannot be described by static networks accurately. In this paper, four structural properties in temporal networks are empirically studied, including degree, clustering coefficient, adjacent correlation, and connected component. Three real temporal networks with different time scales are analyzed in this paper, including short message, telephone, and router networks. Moreover, structural properties of these temporal networks are compared with that of corresponding static aggregation networks in the whole time window. Some essential differences of structural properties between temporal and static networks are achieved through empirical analysis. Finally, the effect of structural properties on spreading dynamics under different time scales is investigated. Some interesting results such as turning point of structure evolving time scale corresponding to certain spreading dynamics time scale from the point of view of infected scale are achieved.

  18. Overstated Optimism: Arizona's Structured English Immersion Program under "Horne v. Flores"

    Science.gov (United States)

    Mora, Jill Kerper

    2010-01-01

    This article is an analysis of the educational implications of the Supreme Court (USSC) decision in "Horne v. Flores" (2009). The USSC remanded the Arizona case to the lower court, requiring a rehearing of petitioners' request for relief from the court's oversight of AZ's "structured English immersion" (SEI) program mandated under HB2064. The…

  19. Local structures of ionic liquids in the presence of gold under high pressures

    Directory of Open Access Journals (Sweden)

    Hai-Chou Chang

    2013-03-01

    Full Text Available The interactions between ionic liquid ([EMI][TFS] and gold surfaces have been investigated via the application of pressures up to ca. 2 GPa. Comparing the spectral features of [EMI][TFS]/gold with those of pure [EMI][TFS], no appreciable changes of C-H bands in the presence of gold powders were observed under ambient pressure. Nevertheless, the imidazolium C-H bands display red shifts in frequency as the [EMI][TFS] / Au mixture was compressed to the pressure above 1.4 GPa and a new alkyl C-H band at ca. 3016 cm−1 was also revealed. These spectral changes, being related to the addition of gold powders and pressure elevation, should be attributed to the local structural changes of C-H groups caused by pressure-enhanced interfacial interactions between [EMI][TFS] and Au. Gold powders tend to induce the changes in hydrogen bonding structures of imidazolium C2-H group under high pressures. The pressure-dependent spectral features in the asymmetric SO3 stretching region display band-narrowing and minor local structural changes induced by the presence of gold particles under high pressures. These observations suggest that Au powders perturb structural equilibrium of C-H groups of cations under high pressures.

  20. Latent factor structure of a behavioral economic cigarette demand curve in adolescent smokers.

    Science.gov (United States)

    Bidwell, L Cinnamon; MacKillop, James; Murphy, James G; Tidey, Jennifer W; Colby, Suzanne M

    2012-11-01

    Behavioral economic demand curves, or quantitative representations of drug consumption across a range of prices, have been used to assess motivation for a variety of drugs. Such curves generate multiple measures of drug demand that are associated with cigarette consumption and nicotine dependence. However, little is known about the relationships among these facets of demand. The aim of the study was to quantify these relationships in adolescent smokers by using exploratory factor analysis to examine the underlying structure of the facets of nicotine incentive value generated from a demand curve measure. Participants were 138 adolescent smokers who completed a hypothetical cigarette purchase task, which assessed estimated cigarette consumption at escalating levels of price/cigarette. Demand curves and five facets of demand were generated from the measure: Elasticity (i.e., 1/α or proportionate price sensitivity); Intensity (i.e., consumption at zero price); O(max) (i.e., maximum financial expenditure on cigarettes); P(max) (i.e., price at which expenditure is maximized); and Breakpoint (i.e., the price that suppresses consumption to zero). Principal components analysis was used to examine the latent structure among the variables. The results revealed a two-factor solution, which were interpreted as "Persistence," reflecting insensitivity to escalating price, and "Amplitude," reflecting the absolute levels of consumption and price. These findings suggest a two factor structure of nicotine incentive value as measured via a demand curve. If supported, these findings have implications for understanding the relationships among individual demand indices in future behavioral economic studies and may further contribute to understanding of the nature of cigarette reinforcement.

  1. Structure and thermoelectric properties of Al-doped ZnO films prepared by thermal oxidization under high magnetic field

    Science.gov (United States)

    Liu, Shiying; Peng, Sunjuan; Ma, Jun; Li, Guojian; Qin, Xuesi; Li, Mengmeng; Wang, Qiang

    2017-04-01

    This paper studies the effects of high magnetic field (HMF) on the structure, optical and thermoelectric properties of the doped ZnO thin films. The results show that both Al dopant and application of HMF can affect the crystal structure, surface morphology, elemental distribution and so on. The particles of the thin films become small and regular by doping Al. The ZnO films oxidized from the Au/Zn bilayer have needle structure. The ZnO films oxidized from the Au/Zn-Al bilayer transform to spherical from hexagonal due to the application of HMF. The transmittance decreases with doping Al because of the opaque of Al element and decreases with the application of HMF due to the dense structure obtained under HMF. Electrical resistivity (ρ) of the ZnO films without Al decreases with increasing measurement temperature (T) and is about 1.5 × 10-3 Ω·m at 210 °C. However, the ρ of the Al-doped ZnO films is less than 10-5 Ω·m. The Seebeck coefficient (S) of the films oxidized from the Au/Zn-Al films reduces with increasing T. The S values oxidized under 0 T and 12 T conditions are 2.439 μV/K and -3.415 μV/K at 210 °C, respectively. Power factor reaches the maximum value (3.198 × 10-4 W/m·K2) at 210 °C for the film oxidized under 12 T condition. These results indicate that the Al dopant and the application of HMF can be used to control structure and thermoelectric properties of doped ZnO films.

  2. Reliability and construct validity of factors underlying the emotional intelligence of Iranian EFL teachers

    Directory of Open Access Journals (Sweden)

    Ebrahim Khodadady

    2013-06-01

    Full Text Available Home Journal Archive V1N3A8Reliability and construct validity of factors underlying the emotional intelligence of Iranian EFL teachers   Ebrahim Khodadady Ferdowsi University of Mashhad Saaber Andargani TabrizFerdowsi University of MashhadInternational Branch, Mashhad, Iran    ABSTRACT The 133-item Emotional Quotient Inventory (EQ-i designed by Bar-On (1997 and translated by Dehshiry (2003 was revised and modified by removing the response validity items, changing reverse indicators into positively worded statements and revising the remaining 117 Persian indicators on the basis of schema theory. It was administered to 669 instructors most of whom were teaching English as a foreign language (EFL in national branches of Iran Language Institute in 15 cities. The application of the Principal Axis Factoring to the data and rotating the extracted factors via Varimax with Kaiser Normalization yielded 15 latent variables (LVs called Humanistic, Self-Satisfying, Self-Confident, Self-Aware, Self-Controlled, Research-Oriented, Content, Sociable, Empathetic, Tolerant, Flexible, Realistic, Independent, Emotional and Happy in this study. Not only did the modified Persian EQ-I proved to be more reliable than its original version, but also its thirteen LVs reached very high and acceptable levels of reliability. With the exception of the last, all the LVs also correlated significantly with each other and thus established the EI as a multifactorial construct whose constituting LVs are closely related to each other. The findings question correlating the so-called competences of EI and offer employing the factorially valid LVs as the best factors to explore the relationship between EI and variables involved in teaching and learning EFL.

  3. Solidification Structure of Continuous Casting Large Round Billets under Mold Electromagnetic Stirring

    Institute of Scientific and Technical Information of China (English)

    Tao SUN; Feng YUE; Hua-jie WU; Chun GUO; Ying LI; Zhong-cun MA

    2016-01-01

    The solidification structure of a continuous casting large round billet was analyzed by a cellular-automaton-finite-element coupling model using the ProCAST software.The actual and simulated solidification structures were compared under mold electromagnetic stirring (MEMS)conditions (current of 300 A and frequency of 3 Hz).There-after,the solidification structures of the large round billet were investigated under different superheats,casting speeds,and secondary cooling intensities.Finally,the effect of the MEMS current on the solidification structures was obtained under fixed superheat,casting speed,secondary cooling intensity,and MEMS frequency.The model accurately simulated the actual solidification structures of any steel,regardless of its size and the parameters used in the continuous casting process.The ratio of the central equiaxed grain zone was found to increase with decreasing su-perheat,increasing casting speed,decreasing secondary cooling intensity,and increasing MEMS current.The grain size obviously decreased with decreasing superheat and increasing MEMS current but was less sensitive to the casting speed and secondary cooling intensity.

  4. Factors mediating the restoration of structurally degraded soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Schjønning, Per;

    with the ability of soils to perform these functions. The present study examines the roles of clay mineralogy, native organic matter, and exogenous organic material on the restoration of structurally degraded soils. Totally seven soils from Denmark and Ghana - five soils dominated by illites, one kaolinitic soil......Soil structure is essential for sustained provision of ecosystem services such as water filtering and storage, waste disposal, carbon sequestration and many more. Structural degradation/disaggregation of soils emanating from human activities such as mining, grading and filling interferes...... and lowest for the smectitic soil. Among the illitic soils, aggregate workability increased with native organic matter content. Addition of exogenous organic material showed little effect on soil physical properties. Results points to the possibility of regenerating the structure of physically degraded soils...

  5. Ordered quasi-two-dimensional structure of nanoparticles in semiflexible ring polymer brushes under compression

    Science.gov (United States)

    Hua, Yunfeng; Deng, Zhenyu; Jiang, Yangwei; Zhang, Linxi

    2017-06-01

    Molecular dynamics simulations of a coarse-grained bead-spring model of ring polymer brushes under compression are presented. Flexible polymer brushes are always disordered during compression, whereas semiflexible polymer brushes tend to be ordered under sufficiently strong compression. Further, the polymer monomer density of the semiflexible polymer brush is very high near the brush surface, inducing a peak value of the free energy near the surface. Therefore, when nanoparticles are compressed in semiflexible ring polymer brushes, they tend to exhibit a closely packed single-layer structure between the brush surface and the impenetrable wall, and a quasi-two-dimensional ordered structure near the brush surface is formed under strong compression. These findings provide a new approach to designing responsive applications.

  6. Identification of Modal Parameters with Linear Structure under Non-stationary Ambient Excitation

    Institute of Scientific and Technical Information of China (English)

    续秀忠; 华宏星; 李中付; 陈兆能

    2004-01-01

    Empirical mode decomposition (EMD) is proposed to identify linear structure under non-stationary excitation,and non-white noise coefficient is introduced under the assumption of random signals consisting of white noise and non-white noise signals. The cross-correlation function of response signal is decomposed into mode functions and residue by EMD method. The identification technique of the modal parameters of single freedom degree is applied to each mode function to obtain natural frequencies, damping ratios and mode shapes. The results of identification of the five-degree freedom linear system demonstrate that the proposed method is effective in identifying the parameters of linear structures under non-stationary ambient excitation.

  7. Numerical Simulation for the Soil-Pile-Structure Interaction under Seismic Loading

    Directory of Open Access Journals (Sweden)

    Lifeng Luan

    2015-01-01

    Full Text Available Piles are widely used as reinforcement structures in geotechnical engineering designs. If the settlement of the soil is greater than the pile, the pile is pulled down by the soil, and negative friction force is produced. Previous studies have mainly focused on the interaction of pile-soil under static condition. However, many pile projects are located in earthquake-prone areas, which indicate the importance of determining the response of the pile-soil structure under seismic load. In this paper, the nonlinear, explicit, and finite difference program FLAC3D, which considers the mechanical behavior of soil-pile interaction, is used to establish an underconsolidated soil-pile mode. The response processes of the pile side friction force, the pile axial force, and the soil response under seismic load are also analyzed.

  8. Factors Affecting the Biomass and Lipid Production from Chlorella sp. TISTR 8990 under Mixotrophic Culture

    Directory of Open Access Journals (Sweden)

    Mohammad Ariful HAQUE

    2012-12-01

    Full Text Available Effects of media compositions on biomass and lipid accumulation of the isolate Chlorella sp. TISTR 8990 were investigated under a Plackett-Burman experimental design with mixotrophic cultivation conditions. Under this experimental design there were 15 different runs with ten factors-yeast extract, KH2PO4, MgSO4, FeSO4, MnCl2, CuSO4, Na2MoO4, H3BO3, ZnSO4 and pH. Cultures were grown mixotrophically under 16 h light and 8 h dark regime at 30 ºC for a period of 7 days. During the light regime, the light intensity at the surface of the vessels and agitation speed were set to 67.5 µmol photons m-2s-1 and 150 rpm, respectively. Initial cell concentration was set to an absorbance (A540 of 0.5. For high biomass production (2.2 g/L, run no. 6, the most effective and significant factors were yeast extract, KH2PO4, FeSO4 and ZnSO4 at concentrations 0.3 g/L, 0.3 g/L, 3 mg/L and 0.3 mg/L, respectively. Whereas for high lipid accumulation (19.59 %DCW, run no. 2, these were KH2PO4, pH and yeast extract, at a level of 1.7 g/L, 6.0 and 0.1 g/L, respectively. No significant factors were obtained for higher lipid content. The best treatment for biomass and lipid content was run no. 6, whose medium formula consisted of 0.3 g/L yeast extract, 1.7 g/L KH2PO4, 1.7 g/L MgSO4, 1 mg/L FeSO4, 0.9 mg/L MnCl2, and pH 7.0, together with fixed concentrations of glucose, NaHCO3 and KNO3 at 5 g/L, 0.05 g/L and 0.5 g/L, respectively.

  9. Structural Analysis of Cuban Typical Model of Telecommunication Self-Supporting Towers under Seismic Load

    Directory of Open Access Journals (Sweden)

    Patricia Martín Rodríguez

    2012-07-01

    Full Text Available Self-supporting lattice towers are slender structures with low damping and high flexibility. They are sensitive to dynamic loads such as wind and earthquake. In the West of Cuba, structures should be analyzed under extreme winds and seismic effects, which raised their frequency during 2010 year. Self-supporting towers do not have the same dynamic behavior as buildings under seismic loads. Their specific structure features are not developed at design seismic codes, for that reason it is necessary to study methods of seismic analysis for self-supporting towers. The methods selected in this research are Modal Analysis Method proposed by Cuban Seismic Code (NC-46:1999 and modal superposition lineal dynamic analysis named Time History. It was selected for the study two self-supporting towers designed in Cuba, Versalles Model (3-legged and Najasa Model (4-legged. Comparative analysis between both methods is realized with extreme values of internal forces at element towers.

  10. Energy Structure and Energy Security under Climate Mitigation Scenarios in China.

    Science.gov (United States)

    Matsumoto, Ken'ichi

    2015-01-01

    This study investigates how energy structure and energy security in China will change in the future under climate mitigation policy scenarios using Representative Concentration Pathways in a computable general equilibrium model. The findings suggest that to reduce greenhouse gas emissions, China needs to shift its energy structure from fossil fuel dominance to renewables and nuclear. The lower the allowable emissions, the larger the shifts required. Among fossil fuels, coal use particularly must significantly decrease. Such structural shifts will improve energy self-sufficiency, thus enhancing energy security. Under the policy scenarios, energy-source diversity as measured by the Herfindahl Index improves until 2050, after which diversity declines because of high dependence on a specific energy source (nuclear and biomass). Overall, however, it is revealed that energy security improves along with progress in climate mitigation. These improvements will also contribute to the economy by reducing energy procurement risks.

  11. Energy Structure and Energy Security under Climate Mitigation Scenarios in China.

    Directory of Open Access Journals (Sweden)

    Ken'ichi Matsumoto

    Full Text Available This study investigates how energy structure and energy security in China will change in the future under climate mitigation policy scenarios using Representative Concentration Pathways in a computable general equilibrium model. The findings suggest that to reduce greenhouse gas emissions, China needs to shift its energy structure from fossil fuel dominance to renewables and nuclear. The lower the allowable emissions, the larger the shifts required. Among fossil fuels, coal use particularly must significantly decrease. Such structural shifts will improve energy self-sufficiency, thus enhancing energy security. Under the policy scenarios, energy-source diversity as measured by the Herfindahl Index improves until 2050, after which diversity declines because of high dependence on a specific energy source (nuclear and biomass. Overall, however, it is revealed that energy security improves along with progress in climate mitigation. These improvements will also contribute to the economy by reducing energy procurement risks.

  12. Structural and elastic properties of Ce2O3 under pressure from LDA+ U method

    Science.gov (United States)

    Qi, Yuan-Yuan; Niu, Zhen-Wei; Cheng, Cai; Cheng, Yan

    2013-08-01

    We investigate the structural and elastic properties of hexagonal Ce2O3 under pressure using LDA+ U scheme in the frame of density functional theory (DFT). The obtained lattice constants and bulk modulus agree well with the available experimental and other theoretical data. The pressure dependences of normalized lattice parameters a/a 0 and c/c 0, ratio c/a, and normalized primitive volume V/V 0 of Ce2O3 are obtained. Moreover, the pressure dependences of elastic properties and three anisotropies of elastic waves of Ce2O3 are investigated for the first time. We find that the negative value of C 44 is indicative of the structural instability of the hexagonal structure Ce2O3 at zero temperature and 30 GPa. Finally, the density of states (DOS) of Ce2O3 under pressure is investigated.

  13. Factor structure of the Disability and Impact Profile in patients with multiple sclerosis

    DEFF Research Database (Denmark)

    Cohen, J. L.; Pouwer, F; Pfennings, L E

    1999-01-01

    and their complementary weighted scores share common variance? What is the factor structure of the weighted scores? To what extent do disease-related information and information from psychological questionnaires offer concurrent validity for the factors? Correlations between impairment ratings and the weighted item...... to sensory-cognitive intactness and a psychological well-being factor. A two-factor solution provides a first factor identical to that of the three-factor solution and a second factor representing psychological well-being. The two factors correlate well with instruments measuring disability...

  14. Structured plant metabolomics for the simultaneous exploration of multiple factors

    Science.gov (United States)

    Vasilev, Nikolay; Boccard, Julien; Lang, Gerhard; Grömping, Ulrike; Fischer, Rainer; Goepfert, Simon; Rudaz, Serge; Schillberg, Stefan

    2016-01-01

    Multiple factors act simultaneously on plants to establish complex interaction networks involving nutrients, elicitors and metabolites. Metabolomics offers a better understanding of complex biological systems, but evaluating the simultaneous impact of different parameters on metabolic pathways that have many components is a challenging task. We therefore developed a novel approach that combines experimental design, untargeted metabolic profiling based on multiple chromatography systems and ionization modes, and multiblock data analysis, facilitating the systematic analysis of metabolic changes in plants caused by different factors acting at the same time. Using this method, target geraniol compounds produced in transgenic tobacco cell cultures were grouped into clusters based on their response to different factors. We hypothesized that our novel approach may provide more robust data for process optimization in plant cell cultures producing any target secondary metabolite, based on the simultaneous exploration of multiple factors rather than varying one factor each time. The suitability of our approach was verified by confirming several previously reported examples of elicitor–metabolite crosstalk. However, unravelling all factor–metabolite networks remains challenging because it requires the identification of all biochemically significant metabolites in the metabolomics dataset. PMID:27853298

  15. Atomic and electronic structure transformations of silver nanoparticles under rapid cooling conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, I; Rojas, J [Instituto Peruano de EnergIa Nuclear, Avenida Canada 1470, Lima 41 (Peru); Landauro, C V; Torres, J [Facultad de Ciencias Fisicas, Universidad Nacional Mayor de San Marcos, P.O. box 14-0149, Lima 14 (Peru)], E-mail: jrojast@unmsm.edu.pe

    2009-02-04

    The structural evolution and dynamics of silver nanodrops Ag{sub 2869} (4.4 nm in diameter) under rapid cooling conditions have been studied by means of molecular dynamics simulations and electronic density of state calculations. The interaction of silver atoms is modelled by a tight-binding semiempirical interatomic potential proposed by Cleri and Rosato. The pair correlation functions and the pair analysis technique are used to reveal the structural transition in the process of solidification. It is shown that Ag nanoparticles evolve into different nanostructures under different cooling processes. At a cooling rate of 1.5625 x 10{sup 13} K s{sup -1} the nanoparticles preserve an amorphous-like structure containing a large amount of 1551 and 1541 pairs which correspond to icosahedral symmetry. For a lower cooling rate (1.5625 x 10{sup 12} K s{sup -1}), the nanoparticles transform into a crystal-like structure consisting mainly of 1421 and 1422 pairs which correspond to the face centred cubic and hexagonal close packed structures, respectively. The variations of the electronic density of states for the differently cooled nanoparticles are small, but in correspondence with the structural changes.

  16. Atomic and electronic structure transformations of silver nanoparticles under rapid cooling conditions

    Science.gov (United States)

    Lobato, I.; Rojas, J.; Landauro, C. V.; Torres, J.

    2009-02-01

    The structural evolution and dynamics of silver nanodrops Ag2869 (4.4 nm in diameter) under rapid cooling conditions have been studied by means of molecular dynamics simulations and electronic density of state calculations. The interaction of silver atoms is modelled by a tight-binding semiempirical interatomic potential proposed by Cleri and Rosato. The pair correlation functions and the pair analysis technique are used to reveal the structural transition in the process of solidification. It is shown that Ag nanoparticles evolve into different nanostructures under different cooling processes. At a cooling rate of 1.5625 × 1013 K s-1 the nanoparticles preserve an amorphous-like structure containing a large amount of 1551 and 1541 pairs which correspond to icosahedral symmetry. For a lower cooling rate (1.5625 × 1012 K s-1), the nanoparticles transform into a crystal-like structure consisting mainly of 1421 and 1422 pairs which correspond to the face centred cubic and hexagonal close packed structures, respectively. The variations of the electronic density of states for the differently cooled nanoparticles are small, but in correspondence with the structural changes.

  17. Evaluation of Stress Intensity Factors for Multiple Cracked Circular Disks Under Crack Surface Tractions with SBFEM

    Institute of Scientific and Technical Information of China (English)

    LIU Jun-yu; LIN Gao; LI Xiao-chuan; XU Feng-lin

    2013-01-01

    Stress intensity factors (SIFs) for the cracked circular disks under different distributing surface tractions are evaluated with the scaled boundary finite element method (SBFEM).In the SBFEM,the analytical advantage of the solution in the radial direction allows SIFs to be directly determined from its definition,therefore no special crack-tip treatment is necessary.Furthermore anisotropic material behavior can be treated easily.Different distributions of surface tractions are considered for the center and double-edge-cracked disks.The benchmark examples are modeled and an excellent agreement between the results in the present study and those in published literature is found.It shows that SBFEM is effective and possesses high accuracy.The SIFs of the cracked orthotropic material circular disks subjected to different surface tractions are also evaluated.The technique of substructure is applied to handle the multiple cracks problem.

  18. [Shifts in metabolism and its regulation under the effect of spaceflight factors].

    Science.gov (United States)

    Larina, I M; Nichiporuk, I A; Veselova, O M; Vasilieva, G Yu; Popova, I A

    2013-01-01

    The review deals with the results of studying the adaptive changes in metabolism and its neuroendocrine regulation in humans and animals under the effect of spaceflight factors and ground-based simulation of the gravitational unloading. The majority of the investigations were concerned with the water-electrolyte and mineral turnover, as well as protein, lipid and carbohydrates metabolism. Biochemical measurements of the body liquids (blood, urine and saliva) before, in and after space flight or in ground simulation experiments were used as indictors of the status of sympathoadrenal, hypothalamo-pituitary-adrenal and other systems involved in systemic regulation of metabolism, and also strength of stress-reaction to adversities. The authors generalized data on the interrelation and interaction of the neuroendocrine and psychophysiological status both in the real and simulated conditions of space flight.

  19. Numerical modeling of nonlinear deformation and buckling of composite plate-shell structures under pulsed loading

    Science.gov (United States)

    Abrosimov, N. A.

    1999-11-01

    Nonlinear three-dimensional problems of dynamic deformation, buckling, and posteritical behavior of composite shell structures under pulsed loads are analyzed. The structure is assumed to be made of rigidly joined plates and shells of revolution along the lines coinciding with the coordinate directions of the joined elements. Individual structural elements can be made of both composite and conventional isotropic materials. The kinematic model of deformation of the structural elements is based on Timoshenko-type hypotheses. This approach is oriented to the calculation of nonstationary deformation processes in composite structures under small deformations but large displacements and rotation angles, and is implemented in the context of a simplified version of the geometrically nonlinear theory of shells. The physical relations in the composite structural elements are based on the theory of effective moduli for individual layers or for the package as a whole, whereas in the metallic elements this is done in the framework of the theory of plastic flow. The equations of motion of a composite shell structure are derived based on the principle of virtual displacements with some additional conditions allowing for the joint operation of structural elements. To solve the initial boundary-value problem formulated, an efficient numerical method is developed based on the finite-difference discretization of variational equations of motion in space variables and an explicit second-order time-integration scheme. The permissible time-integration step is determined using Neumann's spectral criterion. The above method is especially efficient in calculating thin-walled shells, as well as in the case of local loads acting on the structural element, when the discretization grid has to be condensed in the zones of rapidly changing solutions in space variables. The results of analyzing the nonstationary deformation processes and critical loads are presented for composite and isotropic

  20. Isolation, subunit structure, and proteolytic modification of bovine factor VIII.

    Science.gov (United States)

    Legaz, M E; Weinstein, M J; Heldebrant, C M; Davie, E W

    1975-01-20

    A new method has been described for the isolation of factor VIII. The method results in a high yield of factor VIII that is homogeneous by several different criteria. The purified protein is very stable and is not dissociated in the presence of 1 M NaCl or 0.25 M CaCl2. The highly purified protein is readily activated and inactivated by various proteolytic enzymes, such as thrombin, plasmin, and trypsin. The molecular events that lead to the activation reaction, however, have not been established.

  1. Specifics of heat and mass transfer in spherical dimples under the effect of external factors

    Science.gov (United States)

    Shchukin, A. V.; Il'inkov, A. V.; Takmovtsev, V. V.; Khabibullin, I. I.

    2017-06-01

    The specifics are examined of heat transfer enhancement with spherical dimples under the effect of factors important for practice and characteristic of cooling systems of gas-turbine engines and power units. This experimental investigation deals with the effect of the following factors on the flow in a channel with hemispherical dimples: continuous air swirl in an annulus with dimples on its concave wall, dimples on the convex or concave wall of a curved rectangular channel, imposition of regular velocity fluctuations on the external flow in a straight rectangular channel, and adverse or favorable pressure gradient along the flow direction. The flow is turbulent. Reynolds numbers based on the channel hydraulic diameter are on the order of 104. Results of the investigation of a model of a two-cavity diffuser dimple proposed by the authors are presented. It has been found that results for channels with spherical dimples and for smooth channels differ not only quantitatively but also qualitatively. Thus, if the effect of centrifugal mass forces on convex and concave surfaces with hemispherical dimples and in a smooth channel is almost the same (quantitative and qualitative indicators are identical), the pressure gradient in the flow direction brings about the drastically opposite results. At the same time, the quantitative contribution to a change in heat transfer in hemispherical dimples is different and depends on the impact type. The results are discussed with the use of physical models created on the basis of the results of flow visualization studies and data on the turbulence intensity, pressure coefficient, etc. Results of the investigations suggest that application of spherical dimples under nonstandard conditions requires the calculated heat transfer to be corrected to account for one or another effect.

  2. Structural and functional characterization of human complement factor P

    DEFF Research Database (Denmark)

    Pedersen, Dennis

    2016-01-01

    The complement system is of great importance for the innate immune response, which can lead to opsonization and removal of invading pathogens, as well as immune complexes and damaged self-cells. Factor P (FP), also known as properdin, acts as a positive regulator of the alternative pathway...

  3. Conceptualizing schizotypal ambivalence: factor structure and its relationships.

    Science.gov (United States)

    MacAulay, Rebecca K; Brown, Laura S; Minor, Kyle S; Cohen, Alex S

    2014-11-01

    Ambivalence is an important facet of pathology that has received limited attention despite its importance in understanding negative emotionality within schizophrenia spectrum disorders. Central to understanding the role of ambivalence in schizophrenia is characterizing its manifestation within schizotypal individuals-those with the purported genetic liability for schizophrenia. The present study used the Schizotypal Ambivalence Scale (SAS) to examine the nature of ambivalence. An exploratory factor analysis of SAS scores revealed three factors: interpersonal, indecision, and contradictory feelings of ambivalence. Group differences in SAS scores were found such that psychometrically defined schizotypal individuals reported higher levels of ambivalence than controls, and different schizotypy traits exhibited different relationships with SAS factors and quality of life. The inclusion of implicit and explicit measures of positive and negative attitudes revealed that individuals with schizotypy might lack insight into their affective experiences as suggested by the incongruence between our explicit and implicit measures of social attitudes. As hypothesized, the Schizotypal Personality Questionnaire trait dimensions associated with greater SAS ambivalence and the different trait dimensions of schizotypy showed both common and disparate relationships with the ambivalence factors. The current results support the notion that schizotypal ambivalence is a multifaceted construct that not only is affective but also reflects broader processes that dynamically interact with one another to influence functional outcomes.

  4. Epidemiological characteristics and underlying risk factors for mortality during the autumn 2009 pandemic wave in Mexico.

    Directory of Open Access Journals (Sweden)

    Gerardo Chowell

    Full Text Available BACKGROUND: Elucidating the role of the underlying risk factors for severe outcomes of the 2009 A/H1N1 influenza pandemic could be crucial to define priority risk groups in resource-limited settings in future pandemics. METHODS: We use individual-level clinical data on a large series of ARI (acute respiratory infection hospitalizations from a prospective surveillance system of the Mexican Social Security medical system to analyze clinical features at presentation, admission delays, selected comorbidities and receipt of seasonal vaccine on the risk of A/H1N1-related death. We considered ARI hospitalizations and inpatient-deaths, and recorded demographic, geographic, and medical information on individual patients during August-December, 2009. RESULTS: Seasonal influenza vaccination was associated with a reduced risk of death among A/H1N1 inpatients (OR = 0.43 (95% CI: 0.25, 0.74 after adjustment for age, gender, geography, antiviral treatment, admission delays, comorbidities and medical conditions. However, this result should be interpreted with caution as it could have been affected by factors not directly measured in our study. Moreover, the effect of antiviral treatment against A/H1N1 inpatient death did not reach statistical significance (OR = 0.56 (95% CI: 0.29, 1.10 probably because only 8.9% of A/H1N1 inpatients received antiviral treatment. Moreover, diabetes (OR = 1.6 and immune suppression (OR = 2.3 were statistically significant risk factors for death whereas asthmatic persons (OR = 0.3 or pregnant women (OR = 0.4 experienced a reduced fatality rate among A/H1N1 inpatients. We also observed an increased risk of death among A/H1N1 inpatients with admission delays >2 days after symptom onset (OR = 2.7. Similar associations were also observed for A/H1N1-negative inpatients. CONCLUSIONS: Geographical variation in identified medical risk factors including prevalence of diabetes and immune suppression may in part

  5. Guide to Three Dimensional Structure and Motion Factorization

    CERN Document Server

    Wang, Guanghui

    2011-01-01

    The problem of structure and motion recovery from image sequences is an important theme in computer vision. Considerable progress has been made in this field during the past two decades, resulting in successful applications in robot navigation, augmented reality, industrial inspection, medical image analysis, and digital entertainment, among other areas. However, many of these methods work only for rigid objects and static scenes. The study of non-rigid structure from motion is not only of academic significance, but also has important practical applications in real-world, nonrigid or dynamic s

  6. Honorary Authorship Practices in Environmental Science Teams: Structural and Cultural Factors and Solutions.

    Science.gov (United States)

    Elliott, Kevin C; Settles, Isis H; Montgomery, Georgina M; Brassel, Sheila T; Cheruvelil, Kendra Spence; Soranno, Patricia A

    2017-01-01

    Overinclusive authorship practices such as honorary or guest authorship have been widely reported, and they appear to be exacerbated by the rise of large interdisciplinary collaborations that make authorship decisions particularly complex. Although many studies have reported on the frequency of honorary authorship and potential solutions to it, few have probed how the underlying dynamics of large interdisciplinary teams contribute to the problem. This article reports on a qualitative study of the authorship standards and practices of six National Science Foundation-funded interdisciplinary environmental science teams. Using interviews of the lead principal investigator and an early-career member on each team, our study explores the nature of honorary authorship practices as well as some of the motivating factors that may contribute to these practices. These factors include both structural elements (policies and procedures) and cultural elements (values and norms) that cross organizational boundaries. Therefore, we provide recommendations that address the intersection of these factors and that can be applied at multiple organizational levels.

  7. Association between maternal socioeconomic factors and nutritional outcomes in children under 5 years of age,

    Directory of Open Access Journals (Sweden)

    Tatiane Géa-Horta

    Full Text Available Abstract Objective: To estimate the association between maternal socioeconomic factors and the occurrence of nutritional outcomes in children under five years of age in a representative sample of the Brazilian population. Methods: This was a cross-sectional study that evaluated data from the latest National Survey of Children and Women's Demographics and Health, carried out in Brazil in 2006-2007. Maternal employment and maternal level of schooling were the main exposures. The following nutritional outcomes in children were considered: height/age 2SD for overweight. Generalized estimating equations (GEE were utilized as the regression method. Results: After adjustments, it was observed that children whose mothers had low level of schooling had a higher chance of having short stature (OR = 3.97, 95% CI, 1.23-12.80 and children whose mothers worked outside the home were more likely to have excess weight (OR = 1.57, 95% CI, 1.02-2.42. Maternal employment was not associated with short stature in children (OR = 1.09, 95% CI, 0.67-1.77. Conclusion: Maternal level of schooling was associated with short stature in children and maternal employment with overweight, indicating the need to take into account the socioeconomic factors when proposing programs and strategies aimed at health and nutrition improvement of children, considering inter-sectoral interventions.

  8. Hygiene and sanitation risk factors of diarrhoeal disease among under-five children in Ibadan, Nigeria.

    Science.gov (United States)

    Oloruntoba, Elizabeth Omoladun; Folarin, Taiwo Bukola; Ayede, Adejumoke Idowu

    2014-12-01

    Diarrhoea diseases are among the leading causes of morbidity and mortality in under-five-children (U-5C) in Nigeria. Inadequate safe water, sanitation, and hygiene account for the disease burden. Cases of diarrhoea still occur in high proportion in the study area despite government-oriented interventions. To determine the hygiene and sanitation risk factors predisposing U-5C to diarrhoea in Ibadan, Nigeria. Two hundred and twenty pairs of children, matched on age, were recruited as cases and controls over a period of 5 months in Ibadan. Questionnaire and observation checklist were used to obtain information on hygiene practices from caregivers/mothers and sanitation conditions in the households of 30% of the consenting mothers/caregivers. Data were analysed using descriptive and inferential statistics. Caregivers/mothers' mean ages were 31.3 ±7.5 (cases) and 30.6 ±6.0(controls) years. The risk of diarrhoea was significantly higher among children whose mothers did not wash hands with soap before food preparation (OR=3.0, pHygiene and sanitation conditions within households were risk factors for diarrhoea. This study revealed the feasibility of developing and implementing an adequate model to establish intervention priorities in sanitation in Ibadan, Nigeria.

  9. Factors affecting potassium fixation in seven soils under 15-year long-term fertilization

    Institute of Scientific and Technical Information of China (English)

    ZHANG HuiMin; XU MingGang; ZHANG WenJu; HE XinHua

    2009-01-01

    Potassium (K) fixation by seven soils, including black soil, fluvo-aquic soil, grey desert soil, loess soil, paddy soil, red soil and purple soil, was determined by laboratory simulation under a fifteen-year-pe-riod of long-term fertilization. Factors affecting soil K fixation were then discussed by factor analysis and stepwise regression. Magnitude of soil K fixation rate was as follows: the black soil > the purple soil > the loess soil > the fluvo-aquic soil > the paddy soil > the grey desert soil > the red soil. Our re-sulta showed that soil K fixation capacity was significantly affected by the clay mineral types in the soils. Potassium fixation capacity of soils, whose 2:1 layer silicates were dominant minerals, was af-fected by two components extracted by the method of principal component analysis: the first including soil available K, slow available K and K+ saturation, and the second including cation exchange capacity (CEC), soil organic matter (SOM) and <0.002 mm clay contents. Potassium fixation rate was mainly af-fected by K+ saturation and CEC with lower added K concentration (from 0.4 to 1.6 g/L), and by K+ saturation and <0.002 mm clay content with higher added K concentration (from 2.4 to 4.0 g/L).

  10. Horse impoundments under Control of Horses legislation in the Munster region of Ireland: factors affecting euthanasia.

    Science.gov (United States)

    Cullinane, M; O'Sullivan, E; Collins, D M; Byrne, A W; More, S J

    2015-01-24

    Recently, considerable international attention has been paid to the problem of unwanted horses. In Ireland, stray horses, particularly in urban areas, are a further problem. The Control of Horses Act 1996 was enacted in response to an ongoing problem of uncontrolled horses in public places. As yet, no research work has been conducted focusing on stray horses in Ireland. This paper describes horses impounded under the Act in the Munster region of Ireland during 2005-2012 and the factors influencing decisions regarding their disposal. A logistic regression model was developed to investigate factors influencing the probability that a horse was euthanised during impoundment. In total, 3625 seizure events were recorded, most towards the end of the study period. Predictors for euthanasia during 2010-2012 included seizure location, sex, age, colour, body condition score and year. This study highlights the problem of stray horses in Ireland, particularly in urban areas. There is a need for rigorous enforcement of newly enacted horse identification legislation, allowing a fully integrated traceability system. More is required to manage the long-established societal problems of stray horses in urban settings, with a uniform approach by all Local Authorities being long overdue.

  11. Apoptosis: an underlying factor for accelerated periodontal disease associated with diabetes in rats.

    Science.gov (United States)

    Tunalı, Mustafa; Ataoğlu, Tamer; Celik, Ilhami

    2014-09-01

    Diabetes mellitus (DM) is well-established risk factor for periodontal disease. DM can also lead to changes in the number of apoptotic cells in periodontal tissues. The goal of this study was to evaluate apoptosis, depending on DM, in healthy and diseased periodontal soft tissues. A total of 43 adult male Sprague-Dawley rats were used in this study. Experimental periodontitis was created by placing silk ligatures around the cervices of the first mandibular molars. Experimental diabetes was induced by intraperitoneal injection of the diabetogenic agent streptozotocin (STZ). Following the induction of both experimental diseases, the animals were divided into four groups: (1) The healthy group (H) (n = 10); (2) The diabetes group (D) (n = 10); (3) The periodontitis group (P) (n = 11); and (4) The diabetes and periodontitis group (DP) (n = 12). Apoptotic cells were determined by immunohistochemistry, and the frequency of apoptotic cells was evaluated by apoptotic index score. It was observed that there was less apoptosis in both the epithelial and gingival connective tissue cells of healthy diabetic tissues than in healthy tissues without diabetes. When periodontal disease existed, apoptosis increased in both the epithelial and gingival connective tissues of diabetic and non-diabetic animals. There may be differences in the apoptotic mechanisms in the periodontal soft tissues of diabetic and non-diabetic animals. Apoptosis may be one of the underlying factors in increased risk for periodontal disease that is associated with diabetes.

  12. Association between maternal socioeconomic factors and nutritional outcomes in children under 5 years of age.

    Science.gov (United States)

    Géa-Horta, Tatiane; Felisbino-Mendes, Mariana Santos; Ortiz, Renzo Joel Flores; Velasquez-Melendez, Gustavo

    To estimate the association between maternal socioeconomic factors and the occurrence of nutritional outcomes in children under five years of age in a representative sample of the Brazilian population. This was a cross-sectional study that evaluated data from the latest National Survey of Children and Women's Demographics and Health, carried out in Brazil in 2006-2007. Maternal employment and maternal level of schooling were the main exposures. The following nutritional outcomes in children were considered: height/age 2SD for overweight. Generalized estimating equations (GEE) were utilized as the regression method. After adjustments, it was observed that children whose mothers had low level of schooling had a higher chance of having short stature (OR=3.97, 95% CI, 1.23-12.80) and children whose mothers worked outside the home were more likely to have excess weight (OR=1.57, 95% CI, 1.02-2.42). Maternal employment was not associated with short stature in children (OR=1.09, 95% CI, 0.67-1.77). Maternal level of schooling was associated with short stature in children and maternal employment with overweight, indicating the need to take into account the socioeconomic factors when proposing programs and strategies aimed at health and nutrition improvement of children, considering inter-sectoral interventions. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  13. Interrelationships of metal transfer factor under wastewater reuse and soil pollution.

    Science.gov (United States)

    Papaioannou, D; Kalavrouziotis, I K; Koukoulakis, P H; Papadopoulos, F; Psoma, P

    2017-04-20

    The transfer of heavy metals under soil pollution wastewater reuse was studied in a Greenhouse experiment using a randomized block design, including 6 treatments of heavy metals mixtures composed of Zn, Mn, Cd, Co, Cu, Cr, Ni, and Pb, where each metal was taking part in the mixture with 0, 10, 20, 30, 40, 50 mg/kg respectively, in four replications. The Beta vulgaris L (beet) was used as a test plant. It was found that the metal transfer factors were statistically significantly related to the: (i) DTPA extractable soil metals, (ii) the soil pollution level as assessed by the pollution indices, (iii) the soil pH, (iv) the beet dry matter yield and (v) the interactions between the heavy metals in the soil. It was concluded that the Transfer Factor is subjected to multifactor effects and its real nature is complex, and there is a strong need for further study for the understanding of its role in metal-plant relationships. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Characterization of factors underlying the metabolic shifts in developing kernels of colored maize

    Science.gov (United States)

    Hu, Chaoyang; Li, Quanlin; Shen, Xuefang; Quan, Sheng; Lin, Hong; Duan, Lei; Wang, Yifa; Luo, Qian; Qu, Guorun; Han, Qing; Lu, Yuan; Zhang, Dabing; Yuan, Zheng; Shi, Jianxin

    2016-01-01

    Elucidation of the metabolic pathways determining pigmentation and their underlying regulatory mechanisms in maize kernels is of high importance in attempts to improve the nutritional composition of our food. In this study, we compared dynamics in the transcriptome and metabolome between colored SW93 and white SW48 by integrating RNA-Seq and non-targeted metabolomics. Our data revealed that expression of enzyme coding genes and levels of primary metabolites decreased gradually from 11 to 21 DAP, corresponding well with the physiological change of developing maize kernels from differentiation through reserve accumulation to maturation, which was cultivar independent. A remarkable up-regulation of anthocyanin and phlobaphene pathway distinguished SW93 from SW48, in which anthocyanin regulating transcriptional factors (R1 and C1), enzyme encoding genes involved in both pathways and corresponding metabolic intermediates were up-regulated concurrently in SW93 but not in SW48. The shift from the shikimate pathway of primary metabolism to the flavonoid pathway of secondary metabolism, however, appears to be under posttranscriptional regulation. This study revealed the link between primary metabolism and kernel coloration, which facilitate further study to explore fundamental questions regarding the evolution of seed metabolic capabilities as well as their potential applications in maize improvement regarding both staple and functional foods. PMID:27739524

  15. Factor Structure and Psychometric Properties of the Injection Phobia Scale-Anxiety

    Science.gov (United States)

    Olatunji, Bunmi O.; Sawchuk, Craig N.; Moretz, Melanie W.; David, Bieke; Armstrong, Thomas; Ciesielski, Bethany G.

    2010-01-01

    The present investigation examined the factor structure and psychometric properties of the Injection Phobia Scale-Anxiety (IPS-Anx). Principal components analysis of IPS-Anx items in Study 1 (n = 498) revealed a 2-factor structure consisting of Distal Fear and Contact Fear. However, CFA results in Study 2 (n = 567) suggest that a 1-factor…

  16. Determination of pair-structure factor of scattering potential of a collection of particles.

    Science.gov (United States)

    Wang, Tao; Zhao, Daomu

    2010-02-01

    The method of determination of the pair-structure factor of a collection of particles has been discussed. It is shown that the pair-structure factor of scattering potential of the collection of particles can be determined from the cross-spectral density function of the scattered field.

  17. Four-Factor Structure of Obsessive-Compulsive Disorder Symptoms in Children, Adolescents, and Adults

    Science.gov (United States)

    Stewart, S. Evelyn; Rosario, Maria C.; Baer, Lee; Carter, Alice S.; Brown, Timothy A.; Scharf, Jeremiah M.; Illmann, Cornelia; Leckman, James F.; Sukhodolsky, Denis; Katsovich, Lilya; Rasmussen, Steven; Goodman, Wayne; Delorme, Richard; Leboyer, Marion; Chabane, Nadia; Jenike, Michael A.; Geller, Daniel A.; Pauls, David L.

    2008-01-01

    A study was conducted to establish the efficacy of four-factor obsessive-compulsive disorder (OCD) symptom structure for use in child, adolescent and adult groups. Results indicated that the four-factor OCD structure is inadequate for use in children, adolescent and adult age groups.

  18. Factor Structure and Psychometric Properties of the Injection Phobia Scale-Anxiety

    Science.gov (United States)

    Olatunji, Bunmi O.; Sawchuk, Craig N.; Moretz, Melanie W.; David, Bieke; Armstrong, Thomas; Ciesielski, Bethany G.

    2010-01-01

    The present investigation examined the factor structure and psychometric properties of the Injection Phobia Scale-Anxiety (IPS-Anx). Principal components analysis of IPS-Anx items in Study 1 (n = 498) revealed a 2-factor structure consisting of Distal Fear and Contact Fear. However, CFA results in Study 2 (n = 567) suggest that a 1-factor…

  19. Confirming the Factor Structure of the Cognitive Test Anxiety Scale: Comparing the Utility of Three Solutions

    Science.gov (United States)

    Cassady, Jerrell C.; Finch, W. Holmes

    2014-01-01

    This study validated the factor structure of a popular assessment of learner's cognitive test anxiety. Following recent findings in a study with Argentinean students' use of the Spanish version of the Cognitive Test Anxiety Scale (CTAS), this study tested the factor structure using data from 742 students who completed the original English version…

  20. Structure Factors of Berly for the Use in Dynamical Diffraction Studies with X-rays

    OpenAIRE

    Yoshimura, Junichi; Okamura, Mitsuru; Taki, Sadao

    1985-01-01

    For the use in dynamical diffraction works with X-rays, structure factors corresponding to the real and imaginary parts, respectively, of atomic scattering factors were calculated for beryl (Be_3Al_2Si_6O_) from previously reported structural data.

  1. A note on the long rate in factor models of the term structure

    NARCIS (Netherlands)

    de Kort, Jan

    2017-01-01

    In this paper, we consider factor models of the term structure based on a Brownian filtration. We show that the existence of a nondeterministic long rate in a factor model of the term structure implies, as a consequence of the Dybvig–Ingersoll–Ross theorem, that the model has an equivalent

  2. The cooling effect of crushed rock structures on permafrost under an embankment

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the analysis and comparison of soil temperature, thermal regime and permafrost table under the experimental embankment of crushed rock structures in Beiluhe, results show that crushed rock structures provide an extensive cooling effect, which produces a rising permafrost table and decreasing soil temperatures. The rise of the permafrost table under the embankment ranges from an increase of 1.08 m to 1.67 m, with an average of 1.27 m from 2004 to 2007. Mean annual soil temperatures under the crushed rock layer embankment decreased significantly from 2005 to 2007, with average decreases of ?1.03 °C at the depth of 0.5 m, ?1.14 °C at the depth of 1.5 m, and ?0.5 °C at the depth of 5 m. During this period, mean annual soil temperatures under the crushed rock cover embankment showed a slight decrease at shallow depths, with an average decrease of ?0.2 °C at the depth of 0.5 m and 1.5 m, but a slight rise at the depth of 5 m. After the crushed rock structures were closed or crammed with sand, the cooling effect of the crushed rock layer embankment was greatly reduced and that of the crushed rock cover embankment was just slightly reduced.

  3. Changes in the Structure of a Nigerian Soil under Different Land Management Practices

    Directory of Open Access Journals (Sweden)

    Joshua Olalekan Ogunwole

    2015-06-01

    Full Text Available Quantification of soil physical quality (SPQ and pore size distribution (PSD can assist understanding of how changes in land management practices influence dynamics of soil structure, and this understanding could greatly improve the predictability of soil physical behavior and crop yield. The objectives of this study were to measure the SPQ index under two different land management practices (the continuous arable cropping system and natural bush fallow system, and contrast the effects of these practices on the structure of PSD using soil water retention data. Soil water retention curves obtained from a pressure chamber were fitted to van Genuchten’s equation, setting m (= 1-1/n. Although values for soil bulk density were high, soils under the continuous arable cropping system had good SPQ, and maintained the capacity to support root development. However, soils under the natural bush fallow system had a worse structure than the continuous arable system, with restrictions in available water capacity. These two management systems had different PSDs. Results showed the inferiority of the natural bush fallow system with no traffic restriction (which is the common practice in relation to the continuous arable cropping system in regard to physical quality and structure.

  4. Biophysical and sociocultural factors underlying spatial trade-offs of ecosystem services in semiarid watersheds

    Directory of Open Access Journals (Sweden)

    Marina García-Llorente

    2015-09-01

    Full Text Available Biophysical and social systems are linked to form social-ecological systems whose sustainability depends on their capacity to absorb uncertainty and cope with disturbances. In this study, we explored the key biophysical and socio-cultural factors underlying ecosystem service supply in two semiarid watersheds of southern Spain. These included variables associated with the role that freshwater flows and biodiversity play in securing the system's capacity to sustain essential ecosystem services and their relationship with social demand for services, local water governance, and land-use intensification. Our results reveal the importance of considering the invisible dimensions of water and biodiversity, i.e. green freshwater flows and trait-based indicators, because of their relevance to the supply of ecosystem services. Furthermore, they uncover the importance of traditional irrigation canals, a local water governance system, in maintaining the ecosystems' capacity to supply services. The study also highlights the complex trade-offs that occur because of the spatial mismatch between ecosystem service supply (upstream and ecosystem service demand (downstream in watersheds. Finally, we found that land-use intensification generally resulted in losses of the biophysical factors that underpin the supply of some ecosystem services, increases in social demand for less diversified services, and the abandonment of local governance practices. Attempts to manage social-ecological systems toward sustainability at the local scale should identify the key biophysical and socio-cultural factors that are essential for maintaining ecosystem services and should recognize existing interrelationships between them. Land-use management should also take into account ecosystem service trade-offs and the consequences resulting from land-use intensification.

  5. [Mechanisms underlying physiological functions of food factors via non-specific interactions with biological proteins].

    Science.gov (United States)

    Murakami, Akira

    2015-01-01

      We previously reported that zerumbone, a sesquiterpene found in Zingiber zerumbet SMITH, showed notable cancer preventive effects in various organs of experimental rodents. This agent up-regulated nuclear factor-E2-related factor (Nrf2)-dependent expressions of anti-oxidative and xenobiotics-metabolizing enzymes, leading to an increased self-defense capacity. On the other hand, zerumbone markedly suppressed the expression of cyclooxygenase-2, an inducible pro-inflammatory enzyme, by disrupting mRNA stabilizing processes. Binding experiments using a biotin derivative of zerumbone demonstrated that Keap1, an Nrf2 repressive protein, is one of its major binding proteins that promotes their dissociation for inducing Nrf2 transactivation. We then generated a specific antibody against zerumbone-modified proteins and found that zerumbone modified numerous cellular proteins in a non-specific manner, with global distribution of the modified proteins seen not only in cytoplasm but also the nucleus. Based on those observations, zerumbone was speculated to cause proteo-stress, a notion supported by previous findings that it increased the C-terminus of Hsc70 interacting protein-dependent protein ubiquitination and also promoted aggresome formation. Interestingly, zerumbone counteracted proteo-stress and heat stress via up-regulation of the protein quality control systems (PQCs), e.g., heat shock proteins (HSPs), ubiquitin-proteasome, and autophagy. Meanwhile, several phytochemicals, including ursolic acid and curcumin, were identified as marked HSP70 inducers, whereas most nutrients tested were scarcely active. Recent studies have revealed that PQCs play important roles in the prevention of many lifestyle related diseases, such as cancer, thus non-specific binding of phytochemicals to cellular proteins may be a novel and unique mechanism underlying their physiological activities.

  6. Cellular Automata-based Chloride Ion Diffusion Simulation of Concrete Bridges under Multi-factor Coupling Actions

    Institute of Scientific and Technical Information of China (English)

    ZHU Jinsong; HE Likun

    2012-01-01

    Abstract In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time,a cellular automata (CA)-based model is proposed.The process of chloride ion diffusion is analyzed by the CA-based method and a nonlinear solution of the Fick's second law is obtained.Considering the impact of various factors such as stress states,temporal and spatial variability of diffusion parameters and water-cement ratio on the process of chloride ion diffusion,the model of chloride ion diffusion under multi-factor coupling actions is presented.A chloride ion penetrating experiment reported in the literature is used to prove the effectiveness and reasonability of the present method,and a T-type beam is taken as an illustrative example to analyze the process of chloride ion diffusion in practical application.The results indicate that CA-based method can simulate the diffusion of chloride ion in the concrete structures with acceptable precision.

  7. Evaluating the efficacy of distributed detention structures to reduce downstream flooding under variable rainfall, antecedent soil, and structural storage conditions

    Science.gov (United States)

    Thomas, Nicholas W.; Arenas Amado, Antonio; Schilling, Keith E.; Weber, Larry J.

    2016-10-01

    This research systematically analyzed the influence of antecedent soil wetness, rainfall depth, and the subsequent impact on peak flows in a 45 km2 watershed. Peak flows increased with increasing antecedent wetness and rainfall depth, with the highest peak flows occurring under intense precipitation on wet soils. Flood mitigation structures were included and investigated under full and empty initial storage conditions. Peak flows were reduced at the outlet of the watershed by 3-17%. The highest peak flow reductions occurred in scenarios with dry soil, empty project storage, and low rainfall depths. These analyses showed that with increased rainfall depth, antecedent moisture conditions became increasingly less impactful. Scaling invariance of peak discharges were shown to hold true within this basin and were fit through ordinary least squares regression for each design scenario. Scale-invariance relationships were extrapolated beyond the outlet of the analyzed basin to the point of intersection of with and without structure scenarios. In each scenario extrapolated peak discharge benefits depreciated at a drainage area of approximately 100 km2. The associated drainage area translated to roughly 2 km downstream of the Beaver Creek watershed outlet. This work provides an example of internal watershed benefits of structural flood mitigation efforts, and the impact the may exert outside of the basin. Additionally, the influence of 1.8 million in flood reduction tools was not sufficient to routinely address downstream flood concerns, shedding light on the additional investment required to alter peak flows in large basins.

  8. PATH INTEGRAL SOLUTION OF NONLINEAR DYNAMIC BEHAVIOR OF STRUCTURE UNDER WIND EXCITATION

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A numerical scheme for the nonlinear behavior of structure under wind excitation is investigated. With the white noise filter of turbulent-wind fluctuations, the nonlinear motion equation of structures subjected to wind load was modeled as the Ito' s stochastic differential equation. The state vector associated with such a model is a diffusion process. A continuous linearization strategy in the time-domain was adopted.Based on the solution series of its stochastic linearization equations, the formal probabilistic density of the structure response was developed by the path integral technique. It is shown by the numerical example of a guyed mast that compared with the frequency-domain method and the time-domain nonlinear analysis, the proposed approach is highlighted by high accuracy and effectiveness. The influence of the structure non-linearity on the dynamic reliability assessment is also analyzed in the example.

  9. First Passage Probability of Structures under Non-Gaussian Stochastic Behavior

    Institute of Scientific and Technical Information of China (English)

    HE Jun; ZHOU Rong-Jun; KOU Xin-Jian

    2008-01-01

    An analytical moment-based method was proposed for calculating first passage probability of structures under non-Ganssian stochastic behaviour. In the method, the third-moment standardization that constants can be obtained from first three-order response moments was used to map a non-Ganssian structural response into a standard Gaussian process; then the mean up-crossing rates, the mean clump size and the initial passage probability of some critical barrier level by the original structural response were estimated. Finally, the formula for calculating first passage probability was established on the assumption that the corrected up-crossing rates are independent. By a nonlinear single-degree-of-freedom system excited by a stationary Gaussian load,it is demonstrated how the procedure can be used for the type of structures considered. Further, comparisons between the results from the present procedure and those from Monte-Carlo simulation are performed.

  10. Luminaries-level structure improvement of LEDs for heat dissipation enhancement under natural convection

    Indian Academy of Sciences (India)

    Ke Wu; Le Wang; Yi-Bo Yu; Zhi-Yi Huang; Pei Liang

    2013-12-01

    Heat dissipation enhancement of LED luminaries is of great significance to the large-scale application of LED. Luminaries-level structure improvement by the method of boring through-hole is adopted to intensify heat dissipation. Furthermore, the natural convection heat transfer process of LED luminaries is simulated by computational fluid dynamics (CFD) model before and after the structural modification. As shown by computational results, boring through-hole is beneficial to develop bottomto-top natural convection, eliminate local circumfluence, and finally form better flow pattern. Analysis based on field synergy principle shows that boring through-hole across LED luminaries improves the synergy between flow field and temperature field, and effectively decreases the thermal resistance of luminaries-level heat dissipation structure. Under the same computational conditions, by luminaries-level structure improvement the highest temperature of heat sink is decreased by about 8° C and the average heat transfer coefficient is increased by 45.8%.

  11. Spatial variability and temporal stability of throughfall deposition under beech (Fagus sylvatica L.) in relationship to canopy structure

    Energy Technology Data Exchange (ETDEWEB)

    Staelens, Jeroen [Ghent University, Laboratory of Forestry, Geraardsbergsesteenweg 267, 9090 Gontrode (Belgium)]. E-mail: jeroen_staelens@yahoo.com; De Schrijver, An [Ghent University, Laboratory of Forestry, Geraardsbergsesteenweg 267, 9090 Gontrode (Belgium); Verheyen, Kris [Ghent University, Laboratory of Forestry, Geraardsbergsesteenweg 267, 9090 Gontrode (Belgium); Verhoest, Niko E.C. [Ghent University, Laboratory of Hydrology and Water Management, Coupure links 653, 9000 Gent (Belgium)

    2006-07-15

    Although the spatial variability of throughfall (TF) in forest ecosystems can have important ecological implications, little is known about the driving factors of within-stand TF variability, particularly in deciduous forests. While the spatial variability of TF water amount and H{sup +} deposition under a dominant beech (Fagus sylvatica L.) tree was significantly higher in the leafed period than in the leafless period, the spatial TF deposition patterns of most major ions were similar in both periods. The semiannual TF depositions of all ions other than H{sup +} were significantly positively correlated (r = 0.68-0.90, p < 0.05) with canopy structure above sample locations throughout the entire year. The amounts of TF water and H{sup +} deposition during the leafed period were negatively correlated with branch cover. We conclude that the spatial heterogeneity of ion deposition under beech was significantly affected by leaves in the growing period and by branches in non-foliated conditions. - Ion deposition under a deciduous beech tree was strongly affected by the canopy structure throughout the entire year.

  12. Safety factors for structural design-history and developments

    NARCIS (Netherlands)

    Straalen, IJ.J. van

    2000-01-01

    The design of structures is concemed with the generation of solutions and the verification of the reliability. potential design solutions are a result of a process of problem formulation, definition of objeciive functions, conceptual design and optimization. To control this process, many strategies

  13. Molecular Processes Underlying the Structure and Assembly of Thin Films and Nanoparticles at Complex interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Richmond, Geraldine [Univ. of Oregon, Eugene, OR (United States)

    2016-06-03

    carboxylic acid-containing polyelectrolytes at the carbon tetrachloride–water interface, a model system for an oil–water interface. Using VSFS and interfacial tension techniques, these unique set of studies identify the factors that dictate whether or not polyelectrolytes will adsorb to the oil–water interface and also describe the specifics of the adsorption process that depend upon factors such as polymer size, charge density, hydrophobicity, conformation, and the effect of metal ion electrostatics and bonding. The systems studied include polyelectrolytes polyacrylic acid (PAA) and polymethylacrylic acid (PMA) of different polymer sizes and under different aqueous solution conditions. The studies are the first to show the highly ordered nature of the adsorption of the first monolayer with subsequent monolayers disordered. The second set of studies have examined how peptoid nanosheets assemble at the oil/water interface. Peptoid nanosheets are a recently discovered class of two-dimensional (2D) nanomaterial, which form from the self-assembly of a sequence-specific peptoid polymer at an air-water interface. Nanosheet formation occurs first through the assembly of a peptoid monolayer and subsequent compression into a bilayer structure. In these highly successful studies we have shown that the oil-water interface provides another opportunity for growth of these unique and highly ordered peptoid sheets. The monolayer formed at this interface are found through surface spectroscopic measurements to be highly ordered and electrostatic interactions between the charged moieties, namely carboxylate and ammonium residues, of the peptoid are essential in the ability of these peptoids to form ordered nanosheets at the oil-water interface.

  14. Variability of photosynthetic parameters of Pinus sibirica Du Tour needles under changing climatic factors

    Directory of Open Access Journals (Sweden)

    A.P. Zotikova

    2013-12-01

    Full Text Available The air temperature and relative humidity and the intensity of photosynthetically active radiation are the basic ecological factors determining geographical distribution of a species. Wood plant adaptation depends on the intensity of physiological and biochemicalprocesses of plants as a response to changing environmental factors. Investigations to reveal (detect the variability of modification andgenetic components of the photosynthetic parameters in needles of the Siberian cedar (Pinus sibirica Du Tour mountain ecotypes, distributed in central part of the Altai Mountains, were carried out. Also, the survey was extended to some experiments with these ecotypes introduced to mild climate and flat regions from south-western of Siberia. The length and thickness of needles, the size of chloroplasts, content of the photosynthetic pigments, and the functional activity of chloroplastsat the level of photo system II were the evaluated traits. Growing under mountainous conditions (at about 2000m elevation, the two-year-old needles were shorter and thicker and contained very large in size chloroplasts while the content of chlorophylls and carotinoids was twice lower than that in the local ecotype growing in the lowlands. On the other hand, more green and yellow pigments were found in needles of mountain ecotypes planted in the lowlands compared to the local lowland ectype trees. A decrease in pool of the photosynthetic pigments in the highlands ecotypes is probably due to decreased biosynthesis andincreased photo-destruction caused by severe light and temperature conditions. These parameters are likely to be associated withmodifications due to intense insolation, low temperature, ozone concentration, UV radiation, and other negative factors that are morepronounced at high elevation. Despite the large pool of accumulated photosynthetic pigments, the functional activity of chloroplasts in themountain ecotype at the level

  15. Variability of photosynthetic parameters of Pinus sibirica Du Tour needles under changing climatic factors

    Directory of Open Access Journals (Sweden)

    A.P. Zotikova

    2013-12-01

    Full Text Available The air temperature and relative humidity and the intensity of photosynthetically active radiation are the basic ecological factors determining geographical distribution of a species. Wood plant adaptation depends on the intensity of physiological and biochemicalprocesses of plants as a response to changing environmental factors. Investigations to reveal (detect the variability of modification andgenetic components of the photosynthetic parameters in needles of the Siberian cedar (Pinus sibirica Du Tour mountain ecotypes, distributed in central part of the Altai Mountains, were carried out. Also, the survey was extended to some experiments with these ecotypes introduced to mild climate and flat regions from south-western of Siberia. The length and thickness of needles, the size of chloroplasts, content of the photosynthetic pigments, and the functional activity of chloroplastsat the level of photo system II were the evaluated traits. Growing under mountainous conditions (at about 2000m elevation, the two-year-old needles were shorter and thicker and contained very large in size chloroplasts while the content of chlorophylls and carotinoids was twice lower than that in the local ecotype growing in the lowlands. On the other hand, more green and yellow pigments were found in needles of mountain ecotypes planted in the lowlands compared to the local lowland ectype trees. A decrease in pool of the photosynthetic pigments in the highlands ecotypes is probably due to decreased biosynthesis andincreased photo-destruction caused by severe light and temperature conditions. These parameters are likely to be associated withmodifications due to intense insolation, low temperature, ozone concentration, UV radiation, and other negative factors that are morepronounced at high elevation. Despite the large pool of accumulated photosynthetic pigments, the functional activity of chloroplasts in themountain ecotype at the level

  16. Application of LMS-Based NN Structure for Power Quality Enhancement in a Distribution Network Under Abnormal Conditions.

    Science.gov (United States)

    Agarwal, Rahul Kumar; Hussain, Ikhlaq; Singh, Bhim

    2017-03-16

    This paper proposes an application of a least mean-square (LMS)-based neural network (NN) structure for the power quality improvement of a three-phase power distribution network under abnormal conditions. It uses a single-layer neuron structure for the control in a distribution static compensator (DSTATCOM) to attenuate the harmonics such as noise, bias, notches, dc offset, and distortion, injected in the grid current due to connection of several nonlinear loads. This admittance LMS-based NN structure has a simple architecture which reduces the computational complexity and burden which makes it easy to implement. A DSTATCOM is a custom power device which performs various functionalities such as harmonics attenuation, reactive power compensation, load balancing, zero voltage regulation, and power factor correction. Other main contribution of this paper involves operation of the system under abnormal conditions of distribution network which means noise and distortion in voltage and imbalance in three-phase voltages at the point of interconnection. For substantiating and demonstrating the performance of proposed control approach, simulations are carried on MATLAB/Simulink software and corresponding experimental tests are conducted on a developed prototype in the laboratory.

  17. Factors influencing protein tyrosine nitration – structure-based predictive models

    Science.gov (United States)

    Bayden, Alexander S.; Yakovlev, Vasily A.; Graves, Paul R.; Mikkelsen, Ross B.; Kellogg, Glen E.

    2010-01-01

    Models for exploring tyrosine nitration in proteins have been created based on 3D structural features of 20 proteins for which high resolution X-ray crystallographic or NMR data are available and for which nitration of 35 total tyrosines has been experimentally proven under oxidative stress. Factors suggested in previous work to enhance nitration were examined with quantitative structural descriptors. The role of neighboring acidic and basic residues is complex: for the majority of tyrosines that are nitrated the distance to the heteroatom of the closest charged sidechain corresponds to the distance needed for suspected nitrating species to form hydrogen bond bridges between the tyrosine and that charged amino acid. This suggests that such bridges play a very important role in tyrosine nitration. Nitration is generally hindered for tyrosines that are buried and for those tyrosines where there is insufficient space for the nitro group. For in vitro nitration, closed environments with nearby heteroatoms or unsaturated centers that can stabilize radicals are somewhat favored. Four quantitative structure-based models, depending on the conditions of nitration, have been developed for predicting site-specific tyrosine nitration. The best model, relevant for both in vitro and in vivo cases predicts 30 of 35 tyrosine nitrations (positive predictive value) and has a sensitivity of 60/71 (11 false positives). PMID:21172423

  18. The role of non-structural carbohydrate reserves in trees under climatic stress

    Science.gov (United States)

    Hoch, G.; Koerner, C.

    2012-12-01

    The storage of non-structural carbon (C) reserves is an indispensable process for all plants. Diverting parts of their photoassimilates into storage pools (e.g. starch and storage lipids) ensures plants to survive periods when the requirement for C (i.e. the sum of all C-sink activities) exceeds their photosynthetic capacity (C-source activity). Over the last decade, research delivered clear evidence that under the current atmospheric CO2 concentrations, tree growth is generally limited by the availability of resources other than C (e.g. soil nutrients) under most conditions. Whether climatic stresses, like cold temperature or drought, can induce C-limitation in trees is currently vividly debated. We will thus address the following questions: 1) do low temperatures at alpine treelines or drought lead to situations where photosynthesis is limiting growth, and 2) what is the role of non-structural C reserves under such conditions? Trees at the alpine treeline as well as under hydraulic constraints accumulate, rather than use up their non-structural carbohydrate reserves with increasing stress. We propose that this observed increase of C stores results from a stress related decline in growth (C-sink activity) relative to C-supply. Hence, the higher C reserve concentrations found in trees under cold and dry conditions are very likely a direct physiological response to the environmental stress (diversion to storage), reflecting relatively higher availability of photoassimilates compared to sink demand. Previous experiments with trees and crops showed that in cold and dry environments, meristematic growth is generally limited more severely and at an earlier stage than photosynthesis. While cell division and differentiation are close to zero at about 5 °C even in cold adapted species, rates of photosynthesis are still reaching up to 80 % of maximum rates. Similarly, structural growth generally ceases at much less negative water potentials than does photosynthesis, which

  19. Family Structure, Psychosocial Factors, and Cardiovascular Risk Factors in the NHLBI CARDIA Study

    Science.gov (United States)

    2013-11-21

    24) found that for men, having preschool aged children negatively impacted health while having a preschool aged child had protective functions for...2   Psychosocial Factors in the Development of CAD and...177 billion in 2011 (1). Therefore, the study of the contributing factors involved in the development of CAD may ultimately lead to development of

  20. Thermal calculation of ground contact structures: Correction factors of environment- and structure-dependent effects on the heat transfer coefficient

    OpenAIRE

    Nagy, Balázs

    2015-01-01

    The heat loss at ground contact structures is taken into consideration in building heat loss calculations. However, the heat loss through the ground depends not only the soil and the building structure, but the environment as well. New calculation methods based on parametrized transient finite element thermal modelling are introduced in the preceding research article [3]. This paper is the further demonstration of the methods’ environment- or structure-depending correction factors which descr...