WorldWideScience

Sample records for significant structural relationship

  1. The significance of relationships

    Science.gov (United States)

    Burningham, Kate

    2017-12-01

    Understanding individual energy use can inform interventions for energy conservation. A longitudinal qualitative interview study shows that energy use behaviour is not simply a matter of individual choice, but rather is influenced by unique personal circumstances and familial and social relationships, which change over time.

  2. Significant relationship between soil bacterial community structure and incidence of bacterial wilt disease under continuous cropping system.

    Science.gov (United States)

    She, Siyuan; Niu, Jiaojiao; Zhang, Chao; Xiao, Yunhua; Chen, Wu; Dai, Linjian; Liu, Xueduan; Yin, Huaqun

    2017-03-01

    Soil bacteria are very important in biogeochemical cycles and play significant role in soil-borne disease suppression. Although continuous cropping is responsible for soil-borne disease enrichment, its effect on tobacco plant health and how soil bacterial communities change are yet to be elucidated. In this study, soil bacterial communities across tobacco continuous cropping time-series fields were investigated through high-throughput sequencing of 16S ribosomal RNA genes. The results showed that long-term continuous cropping could significantly alter soil microbial communities. Bacterial diversity indices and evenness indices decreased over the monoculture span and obvious variations for community structures across the three time-scale tobacco fields were detected. Compared with the first year, the abundances of Arthrobacter and Lysobacter showed a significant decrease. Besides, the abundance of the pathogen Ralstonia spp. accumulated over the monoculture span and was significantly correlated with tobacco bacterial wilt disease rate. Moreover, Pearson's correlation demonstrated that the abundance of Arthrobacter and Lysobacter, which are considered to be beneficial bacteria had significant negative correlation with tobacco bacterial wilt disease. Therefore, after long-term continuous cropping, tobacco bacterial wilt disease could be ascribed to the alteration of the composition as well as the structure of the soil microbial community.

  3. THE SIGNIFICANCE OF STRUCTURAL AND GEOLOGICAL RELATIONSHIP ASSESSMENT IN THE CONSTRUCTION OF THE OMBLA UNDERGROUND HYDROELECTRIC POWER PLANT

    Directory of Open Access Journals (Sweden)

    Renato Buljan

    1997-12-01

    Full Text Available The construction design of the underground hydroelectric plant Ombla required geological and structural investigations to he carried out. Due to past earthquakes in the area permanent tectonic movements were inferred. Therefore, in the wider and adjacent surroundings of the Ombla spring it was necessary to analyze the structural fabric and the geodynamic characteristics of the area. The most active zone encountered is the front part of a thrust fault belonging to the Dinaricum regional structural unit. The compressive regime is maintained as a response to the regional stress of an approximately S-N orientation. Different displacements of various parts of the Dinaricum unit are present. Along the rim of the structural blocks, the Hum-Om-bla fault zone extends, accompanied by left transcurrent faults, Through this zone the main groundwater drainage occurs supplying the Ombla spring. In the local Ombla spring area this zone is characterized by three sub-blocks and three major faults. The most important fault for the vital facilities of the Ombla hydroelectric power plant is the Pločice fault which divides the structural sub-blocks. Along this fault zone there are four mutually connected. The lowest two arc active groundwater draining systems supplying the Ombla spring. The data on local stress implies the following deformation of sub-blocks: sub-blocks 2c and 2f are displaced along normal faults from 20° to 30° to the left, downwards, while the sub-block 2 d is displaced along the Pločice thrust fault of 100° to 130° to the left, upwards. The structural data confirmed that the building of an underground dam with a height from 100 to 130 m was feasible. The connection between the caverns and the fault zone was determined. The unfavorable position of the active Pločice fault zone imposes the construction of vital Ombla power plant facilities underground.

  4. Changing relationships with significant others: Reflections of ...

    African Journals Online (AJOL)

    Symbolic interactionism provides the framework for analysing the building of relationships between elite athletes and their significant others. In-depth interviews were conducted with elite throwers and decathlon athletes. The sample included current (n=15) and retired (n=5) student-athletes, parents (n=5), coaches (n=2) ...

  5. The therapeutic relationship: historical development and contemporary significance.

    Science.gov (United States)

    O'Brien, A J

    2001-04-01

    The therapeutic relationship is a concept held by many to be fundamental to the identity of mental health nurses. While the therapeutic relationship was given formal expression in nursing theory in the middle of the last century, its origins can be traced to attendants' interpersonal practices in the asylum era. The dominance of medical understandings of mental distress, and the working-class status of asylum attendants, prevented the development of an account of mental health nursing based on attendants' relationships with asylum inmates. It was left to Peplau and other nursing theorists to describe mental health nursing as a therapeutic relationship in the 1940s and later. Some distinctive features of colonial life in New Zealand suggest that the ideal of the attendant as the embodiment of bourgeoisie values seems particularly unlikely to have been realized in the New Zealand context. However, New Zealand literature from the 20th century shows that the therapeutic relationship, as part of a general development of a therapeutic discourse, came to assume a central place in conceptualizations of mental health nursing. While the therapeutic relationship is not by itself a sufficient basis for professional continuity, it continues to play a fundamental role in mental health nurses' professional identity. The way in which the therapeutic relationship is articulated in the future will determine the meaning of the therapeutic relationship for future generations of mental health nurses.

  6. Structural mode significance using INCA. [Interactive Controls Analysis computer program

    Science.gov (United States)

    Bauer, Frank H.; Downing, John P.; Thorpe, Christopher J.

    1990-01-01

    Structural finite element models are often too large to be used in the design and analysis of control systems. Model reduction techniques must be applied to reduce the structural model to manageable size. In the past, engineers either performed the model order reduction by hand or used distinct computer programs to retrieve the data, to perform the significance analysis and to reduce the order of the model. To expedite this process, the latest version of INCA has been expanded to include an interactive graphical structural mode significance and model order reduction capability.

  7. Relationship between pore structure and compressive strength

    Indian Academy of Sciences (India)

    Properties of concrete are strongly dependent on its pore structure features, porosity being an important one among them. This study deals with developing an understanding of the pore structure-compressive strength relationship in concrete. Several concrete mixtures with different pore structures are proportioned and ...

  8. Prognostic significance of delayed structural recovery after macular hole surgery

    DEFF Research Database (Denmark)

    Christensen, Ulrik C; Krøyer, Kristian; Sander, Birgit

    2009-01-01

    was used; however, secondary macular hole surgery had a significant influence on diameter of photoreceptor layer discontinuity at 3 months. CONCLUSIONS: Structural recovery in the form of photoreceptor layer discontinuity with a diameter of more than approximately 1500 microm 3 months after macular hole...

  9. On the Question of Methodological Support of Research on Relationships of Interpersonal Significance in Kindergarten Groups

    Directory of Open Access Journals (Sweden)

    Iliyn V.A.

    2016-03-01

    Full Text Available The paper focuses on the importance of in-depth research (in particular, employing an algorithm developed by M.Yu. Kondratyev for defining integral status of an individual on child-child interpersonal relationship in kindergarten groups. Although relationships with significant adults are by all means essential for preschool children, interpersonal relation- ships on the child-child level to a great extent shape the content of the social situation of development in general. Still, when it comes to revealing status and role position of the child in the structure of interpersonal relationships within the kindergarten group, there’s the challenge of defining informal intragroup structure of power in contact community (due to the age specifics. The paper suggests how this challenge may be addressed and provides a version of the technique suitable for preschoolers that helps overcome age restrictions implied by the original technique. Also, the paper reports on the outcomes of approbation of this version which proved its heuristic nature. For instance, the outcomes show a high degree of correlation between the results of kindergarten group members ranking in accordance with their influence upon peers carried out by teachers working in these groups.

  10. Structure-function relationships of human meniscus.

    Science.gov (United States)

    Danso, Elvis K; Oinas, Joonas M T; Saarakkala, Simo; Mikkonen, Santtu; Töyräs, Juha; Korhonen, Rami K

    2017-03-01

    Biomechanical properties of human meniscus have been shown to be site-specific. However, it is not known which meniscus constituents at different depths and locations contribute to biomechanical properties obtained from indentation testing. Therefore, we investigated the composition and structure of human meniscus in a site- and depth-dependent manner and their relationships with tissue site-specific biomechanical properties. Elastic and poroelastic properties were analyzed from experimental stress-relaxation and sinusoidal indentation measurements with fibril reinforced poroelastic finite element modeling. Proteoglycan (PG) and collagen contents, as well as the collagen orientation angle, were determined as a function of tissue depth using microscopic and spectroscopic methods, and they were compared with biomechanical properties. For all the measurement sites (anterior, middle and posterior) of lateral and medial menisci (n=26), PG content and collagen orientation angle increased as a function of tissue depth while the collagen content had an initial sharp increase followed by a decrease across tissue depth. The highest values (pmeniscus. This location had also higher (pmeniscus, higher (pmeniscus) significantly higher (pmeniscus modulus and/or nonlinear permeability. This study suggests that nonlinear biomechanical properties of meniscus, caused by the collagen network and fluid, may be strongly influenced by tissue osmotic swelling from the deep meniscus caused by the increased PG content, leading to increased collagen fibril tension. These nonlinear biomechanical properties are suggested to be further amplified by higher collagen content at all tissue depths and superficial collagen fibril orientation. However, these structure-function relationships are suggested to be highly site-specific. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Family structure and its relationship to travel

    Science.gov (United States)

    Christine Cornell McCreedy; Joseph T. O' Leary; Daniel Fesenmaier

    1992-01-01

    This paper examines the relationship between family structure and travel to further understand what differences exist between family groups. Results indicate that the absence of a husband delays travel for single mothers and that they are not as well-off as their married counterparts. We examine other travel and leisure studies to make comparisons with these data,...

  12. Physiological significance, structure and isolation of α-lactalbumin

    Directory of Open Access Journals (Sweden)

    Katarina Lisak Jakopović

    2016-01-01

    Full Text Available Along with the constant increase in the cheese milk production, the world whey production is increasing constantly too (>2 % per year. The excellent nutritional properties attributed to whey are mainly conditioned by the presence of highly valuable proteins with wide range of biological and functional properties. The main whey proteins are β-lactoglobulin (β-Lg and α-lactalbumin (α-La which are extensively used in functional foods and beverages, infant formulas, sport diets, but are a very good source of bioactive peptides too. Along with casein, β-Lg is most commonly made responsible for causing food allergies, especially in infants whose digestion system isn’t completely developed. Hence, there is a great interest for removing β-Lg prior to whey utilization in certain products. At the same time α-La was recognized as the nutritionally most valuable protein and might be regarded as an ideal ingredient for infant formulas. Thus, the aim of the present paper was to give an overview of the currently available methods for α-La isolation, and to highlight their advantages and disadvantages as well. Also, this paper reviews the most recent insights related to the structure and physiological significance of α-La.

  13. Structure and Structure-activity Relationship of Functional Organic Molecules

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Research theme The group is made up of junior scientists from the State Key Laboratory of Elemento-organic Chemistry, Nankai University.The scientists focus their studis on the structure and structure-activity relationship of functional organic molecules not only because it has been the basis of their research, but also because the functional study of organic compounds is now a major scientific issue for organic chemists around the world.

  14. Significance tests for functional data with complex dependence structure

    KAUST Repository

    Staicu, Ana-Maria; Lahiri, Soumen N.; Carroll, Raymond J.

    2015-01-01

    We propose an L (2)-norm based global testing procedure for the null hypothesis that multiple group mean functions are equal, for functional data with complex dependence structure. Specifically, we consider the setting of functional data with a

  15. Structural and functional significance of water permeation through cotransporters

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; Gorraitz, Edurne; Her, Ka

    2016-01-01

    Membrane transporters, in addition to their major role as specific carriers for ions and small molecules, can also behave as water channels. However, neither the location of the water pathway in the protein nor their functional importance is known. Here, we map the pathway for water and urea...... through the intestinal sodium/glucose cotransporter SGLT1. Molecular dynamics simulations using the atomic structure of the bacterial transporter vSGLT suggest that water permeates the same path as Na+ and sugar. On a structural model of SGLT1, based on the homology structure of vSGLT, we identified...... to be due to alterations in steric hindrance to water and urea, and/or changes in protein folding caused by mismatching of side chains in the water pathway. Water permeation through SGLT1 and other transporters bears directly on the structural mechanism for the transport of polar solutes through...

  16. The phylogenetic significance of fruit structures in ranunculaceae of china

    International Nuclear Information System (INIS)

    Cheng, X.Y.; Liu, M.; Shi, C.Q.; Ru, J.

    2015-01-01

    The external and internal structures of fruits from 95 taxa representing 27 Ranunculaceae genera of China were studied. The results show that Ranunculaceae could be divided into 4 groups based on the fruit types, epidermal surface, vascular bundle, mesocarp cell, and endocarp cell structures: Group 1: follicle or achene, branching or branching and anastomosing vascular bundles, mesocarp parenchyma, and endocarp with one layer of lignified cells (including Aconitum and other genera); Group 2: achene, vascular bundle branching, mesocarp lignified, endocarp with one layer of irregular and partly lignified cells (Thalictrum only); Group 3: achene, endocarp with multilayered thick-walled cells (including Adonis, Batrachium and Ranunculus); Group 4: achene, two non-branching vascular bundles, and endocarp with one layer of fibers (including Anemone, Clematis and Pulsatilla). This study show that the fruit structures of Ranunculaceae could provide morphological and anatomical evidences for molecular phylogeny. (author)

  17. Significance tests for functional data with complex dependence structure.

    Science.gov (United States)

    Staicu, Ana-Maria; Lahiri, Soumen N; Carroll, Raymond J

    2015-01-01

    We propose an L 2 -norm based global testing procedure for the null hypothesis that multiple group mean functions are equal, for functional data with complex dependence structure. Specifically, we consider the setting of functional data with a multilevel structure of the form groups-clusters or subjects-units, where the unit-level profiles are spatially correlated within the cluster, and the cluster-level data are independent. Orthogonal series expansions are used to approximate the group mean functions and the test statistic is estimated using the basis coefficients. The asymptotic null distribution of the test statistic is developed, under mild regularity conditions. To our knowledge this is the first work that studies hypothesis testing, when data have such complex multilevel functional and spatial structure. Two small-sample alternatives, including a novel block bootstrap for functional data, are proposed, and their performance is examined in simulation studies. The paper concludes with an illustration of a motivating experiment.

  18. Significance tests for functional data with complex dependence structure

    KAUST Repository

    Staicu, Ana-Maria

    2015-01-01

    We propose an L (2)-norm based global testing procedure for the null hypothesis that multiple group mean functions are equal, for functional data with complex dependence structure. Specifically, we consider the setting of functional data with a multilevel structure of the form groups-clusters or subjects-units, where the unit-level profiles are spatially correlated within the cluster, and the cluster-level data are independent. Orthogonal series expansions are used to approximate the group mean functions and the test statistic is estimated using the basis coefficients. The asymptotic null distribution of the test statistic is developed, under mild regularity conditions. To our knowledge this is the first work that studies hypothesis testing, when data have such complex multilevel functional and spatial structure. Two small-sample alternatives, including a novel block bootstrap for functional data, are proposed, and their performance is examined in simulation studies. The paper concludes with an illustration of a motivating experiment.

  19. The significance of structural power in Strategic Environmental Assessment

    International Nuclear Information System (INIS)

    Hansen, Anne Merrild; Kørnøv, Lone; Cashmore, Matthew; Richardson, Tim

    2013-01-01

    This article presents a study of how power dynamics enables and constrains the influence of actors upon decision-making and Strategic Environmental Assessment (SEA). Based on structuration theory, a model for studying power dynamics in strategic decision-making processes is developed. The model is used to map and analyse key decision arenas in the decision process of aluminium production in Greenland. The analysis shows that communication lines are an important resource through which actors exercise power and influence decision-making on the location of the aluminium production. The SEA process involved not only reproduction of formal communication and decision competence but also production of alternative informal communication structures in which the SEA had capability to influence. It is concluded, that actors influence strategic decision making, and attention needs to be on not only the formal interactions between SEA process and strategic decision-making process but also on informal interaction and communication between actors as the informal structures, which can be crucial to the outcome of the decision-making process. This article is meant as a supplement to the understanding of power dynamics influence in IA processes and as a contribution to the IA research field with a method to analyse power dynamics in strategic decision-making processes. The article also brings reflections of strengths and weaknesses of using the structuration theory as an approach to power analysis. - Highlights: ► Informal interaction influenced process despite the presence of formalised rules. ► Interdependence of actors influenced SEA effectiveness. ► SEA practitioners successfully exercised power to influence decision-making. ► Power dynamics are properties of actors' interactions in decision-making. ► Power structures can be enabling and not solely limiting.

  20. Structural relationships and vasorelaxant activity of monoterpenes

    Directory of Open Access Journals (Sweden)

    Cardoso Lima Tamires

    2012-09-01

    Full Text Available Abstract Background and purpose of the study The hypotensive activity of the essential oil of Mentha x villosa and its main constituent, the monoterpene rotundifolone, have been reported. Therefore, our objective was to evaluate the vasorelaxant effect of monoterpenes found in medicinal plants and establish the structure-activity relationship of rotundifolone and its structural analogues on the rat superior mesenteric artery. Methods Contractions of the vessels were induced with 10 μM of phenylephine (Phe in rings with endothelium. During the tonic phase of the contraction, the monoterpenes (10-8 - 10-3, cumulatively were added to the organ bath. The extent of relaxation was expressed as the percentage of Phe-induced contraction. Results The results from the present study showed that both oxygenated terpenes (rotundifolone, (+-limonene epoxide, pulegone epoxide, carvone epoxide, and (+-pulegone and non-oxygenated terpene ((+-limonene exhibit relaxation activity. The absence of an oxygenated molecular structure was not a critical requirement for the molecule to be bioactive. Also it was found that the position of ketone and epoxide groups in the monoterpene structures influence the vasorelaxant potency and efficacy. Major conclusion The results suggest that the presence of functional groups in the chemical structure of rotundifolone is not essential for its vasorelaxant activity.

  1. The significance of structural power in Strategic Environmental Assessment

    DEFF Research Database (Denmark)

    Hansen, Anne Merrild; Kørnøv, Lone; Cashmore, Matthew Asa

    2013-01-01

    , that actors influence both outcome and frames for strategic decision making and attention needs to be on not only the formal interactions between SEA process and strategic decision-making process but also on informal interaction and communication between actors. The informal structures shows crucial...... to the outcome of the decision-making process. The article is meant as a supplement to the understanding of power dynamics influence in IA processes emphasising the capacity of agents to mobilise and create change. Despite epistemological challenges of using ST theory as an approach to power analysis, this meta......This article presents a study of how power dynamics enables and constrains the influence of actors upon decision-making and Strategic Environmental Assessment (SEA). Based on Anthony Giddens structuration theory (ST), a model for studying power dynamics in strategic decision-making processes...

  2. Neglect Of Parameter Estimation Uncertainty Can Significantly Overestimate Structural Reliability

    Directory of Open Access Journals (Sweden)

    Rózsás Árpád

    2015-12-01

    Full Text Available Parameter estimation uncertainty is often neglected in reliability studies, i.e. point estimates of distribution parameters are used for representative fractiles, and in probabilistic models. A numerical example examines the effect of this uncertainty on structural reliability using Bayesian statistics. The study reveals that the neglect of parameter estimation uncertainty might lead to an order of magnitude underestimation of failure probability.

  3. Structure-cytotoxicity relationships for dietary flavonoids

    DEFF Research Database (Denmark)

    Breinholt, V.; Dragsted, L.O.

    1998-01-01

    The cytotoxicity of a large series of dietary flavonoids was tested in a non-tumorigenic mouse and two human cancer cell lines, using the neutral red dye exclusion assay. All compounds tested exhibited a concentration-dependent cytotoxic action in the employed cell lines. The relative cytotoxicity...... of the flavonoids, however, Tvas found to vary greatly among the different cell Lines. With a few exceptions, the investigated flavonoids were more cytotoxic to the human cancer cell lines, than the mouse cell line. The differences in cytotoxicity were accounted for in part by differences in cellular uptake...... and metabolic capacity among the different cell types. In 3T3 cells fairly consistent structure-cytotoxicity relationships were found. The most cytotoxic structures tested in 3T3 cells were flavonoids with adjacent 3',4' hydroxy groups on the B-ring, such as luteolin, quercetin, myricetin, fisetin, eriodictyol...

  4. Trichothecenes: structure-toxic activity relationships.

    Science.gov (United States)

    Wu, Qinghua; Dohnal, Vlastimil; Kuca, Kamil; Yuan, Zonghui

    2013-07-01

    Trichothecenes comprise a large family of structurally related toxins mainly produced by fungi belonging to the genus Fusarium. Among trichothecenes, type A and type B are of the most concern due to their broad and highly toxic nature. In order to address structure-activity relationships (SAR) of trichothecenes, relationships between structural features and biological effects of trichothecene mycotoxins in mammalian systems are summarized in this paper. The double bond between C-9-C-10 and the 12,13-epoxide ring are essential structural features for trichothecene toxicity. Removal of these groups results in a complete loss of toxicity. A hydroxyl group at C-3 enhances trichothecene toxicity, while this activity decreases gradually when C-3 is substituted with either hydrogen or an acetoxy group. The presence of a hydroxyl group at C-4 promotes slightly lower toxicity than an acetoxy group at the same position. The toxicity for type B trichothecenes decreases if the substituent at C-4 is changed from acetoxy to hydroxyl or hydrogen at C-4 position. The presence of hydroxyl and hydrogen groups on C-15 decreases the trichothecene toxicity in comparison with an acetoxy group attached to this carbon. Trichothecenes toxicity increases when a macrocyclic ring exists between the C-4 and C-15. At C-8 position, an oxygenated substitution at C-8 is essential for trichothecene toxicity, indicating a decrease in the toxicity if substituent change from isovaleryloxy through hydrogen to the hydroxyl group. The presence of a second epoxy ring at C-7-C-8 reduces the toxicity, whereas epoxidation at C-9-C-10 of some macrocyclic trichothecenes increases the activity. Conjugated trichothecenes could release their toxic precursors after hydrolysis in animals, and present an additional potential risk. The SAR study of trichothecenes should provide some crucial information for a better understanding of trichothecene chemical and biological properties in food contamination.

  5. Familial identification: population structure and relationship distinguishability.

    Science.gov (United States)

    Rohlfs, Rori V; Fullerton, Stephanie Malia; Weir, Bruce S

    2012-02-01

    With the expansion of offender/arrestee DNA profile databases, genetic forensic identification has become commonplace in the United States criminal justice system. Implementation of familial searching has been proposed to extend forensic identification to family members of individuals with profiles in offender/arrestee DNA databases. In familial searching, a partial genetic profile match between a database entrant and a crime scene sample is used to implicate genetic relatives of the database entrant as potential sources of the crime scene sample. In addition to concerns regarding civil liberties, familial searching poses unanswered statistical questions. In this study, we define confidence intervals on estimated likelihood ratios for familial identification. Using these confidence intervals, we consider familial searching in a structured population. We show that relatives and unrelated individuals from population samples with lower gene diversity over the loci considered are less distinguishable. We also consider cases where the most appropriate population sample for individuals considered is unknown. We find that as a less appropriate population sample, and thus allele frequency distribution, is assumed, relatives and unrelated individuals become more difficult to distinguish. In addition, we show that relationship distinguishability increases with the number of markers considered, but decreases for more distant genetic familial relationships. All of these results indicate that caution is warranted in the application of familial searching in structured populations, such as in the United States.

  6. Familial identification: population structure and relationship distinguishability.

    Directory of Open Access Journals (Sweden)

    Rori V Rohlfs

    2012-02-01

    Full Text Available With the expansion of offender/arrestee DNA profile databases, genetic forensic identification has become commonplace in the United States criminal justice system. Implementation of familial searching has been proposed to extend forensic identification to family members of individuals with profiles in offender/arrestee DNA databases. In familial searching, a partial genetic profile match between a database entrant and a crime scene sample is used to implicate genetic relatives of the database entrant as potential sources of the crime scene sample. In addition to concerns regarding civil liberties, familial searching poses unanswered statistical questions. In this study, we define confidence intervals on estimated likelihood ratios for familial identification. Using these confidence intervals, we consider familial searching in a structured population. We show that relatives and unrelated individuals from population samples with lower gene diversity over the loci considered are less distinguishable. We also consider cases where the most appropriate population sample for individuals considered is unknown. We find that as a less appropriate population sample, and thus allele frequency distribution, is assumed, relatives and unrelated individuals become more difficult to distinguish. In addition, we show that relationship distinguishability increases with the number of markers considered, but decreases for more distant genetic familial relationships. All of these results indicate that caution is warranted in the application of familial searching in structured populations, such as in the United States.

  7. Modeling cell-in-cell structure into its biological significance

    OpenAIRE

    He, M-f; Wang, S; Wang, Y; Wang, X-n

    2013-01-01

    Although cell-in-cell structure was noted 100 years ago, the molecular mechanisms of ?entering' and the destination of cell-in-cell remain largely unclear. It takes place among the same type of cells (homotypic cell-in-cell) or different types of cells (heterotypic cell-in-cell). Cell-in-cell formation affects both effector cells and their host cells in multiple aspects, while cell-in-cell death is under more intensive investigation. Given that cell-in-cell has an important role in maintainin...

  8. The relationship between Prostate CAncer gene 3 (PCA3) and prostate cancer significance

    NARCIS (Netherlands)

    van Poppel, Hein; Haese, Alexander; Graefen, Markus; de la Taille, Alexandre; Irani, Jacques; de Reijke, Theo; Remzi, Mesut; Marberger, Michael

    2012-01-01

    OBJECTIVE To evaluate the relationship between Prostate CAncer gene 3 (PCA3) and prostate cancer significance. PATIENTS AND METHODS Clinical data from two multi-centre European open-label, prospective studies evaluating the clinical utility of the PCA3 assay in guiding initial and repeat biopsy

  9. The epidermis in Passerina/ (Thymelaeaceae: structure, function and taxonomic significance

    Directory of Open Access Journals (Sweden)

    C. L. Bredenkamp

    2000-02-01

    Full Text Available Epidermal features were studied in all 17 species of Passerina, a genus endemic to southern Africa. Leaves in Passerina are inversely ericoid, the adaxial surface concave and the abaxial surface convex. Leaves are inversely dorsiventral and epistomatic. The adaxial epidermis is villous, with unicellular, uniseriate trichomes and relatively small thin-walled cells, promoting flexibility of leaf margins owing to turgor changes. In common with many other Thymelaeaceae, abaxial epidermal cells are large and tanniniferous with mucilaginous cell walls. The cuticle is adaxially thin, but abaxially well devel­oped, probably enabling the leaf to restrict water loss and to tolerate high light intensity and UV-B radiation. Epicuticular waxes, present in all species, comprise both soft and plate waxes. Epidermal structure proves to be taxonomically impor­tant at family, genus and species levels. Interspecific differences include arrangement of stomata and presence or absence of abaxial epidermal hair. Other diagnostic characters of the abaxial epidermal cells are arrangement,size and shape, cutic- ular ornamentation and presence or absence of wax platelets. Two groups of species on the basis of abaxial epidermal cell orientation are recognised. Many leaf epidermal features in Passerina are interpreted as structural adaptations to the Mediterranean climate of the Cape.

  10. Vegetation composition and structure significantly influence green roof performance

    Energy Technology Data Exchange (ETDEWEB)

    Dunnett, N.; Nagase, A.; Booth, R.; Grime, P. [Sheffield Univ., Sheffield (United Kingdom). Dept. of Landscape Architecture

    2005-07-01

    The majority of published literature on green roofs contains little specific information on the contribution of plants to the various functions and properties of green roofs. This paper reviewed previously published material in an attempt to shed light on the role of vegetation composition in green roof systems, with specific reference to hydrology and biodiversity support. Two ongoing experiments at the University of Sheffield were then considered: (1) a comparison of quality and quantity of runoff from different types of vegetation; and (2) a comparison of flowering seasons and biodiversity support of different vegetation. Results of the studies showed that there was no general pattern of variation in runoff that could be related to vegetation complexity or taxonomic composition of the communities. During the winter months, high precipitation quickly saturated the soil and percolate losses were similar for all treatments. In the summer, throughflow losses differed between treatments in relation to the structure of the plant canopy. Differing mechanisms resulted in variations in the volume of percolate that was collected. Lower volumes of percolate were observed in herb-only monocultures of Leontdon hispidus, a species with a high water content. Tap-rooted species were seen to more effectively absorb soil moisture. The biodiversity support study focused on the study of Sedum species and Labiatae species, which suggested that mixed vegetation containing these species had a far greater likelihood of attracting wild bees to support pollination. Results of the studies indicated that green roof vegetation with greater structural and species diversity may provide different benefits than sedum-dominated roots. Further studies are needed to investigate the trade-offs between vegetation types, and green roof functions and performance in order to justify calls for a wider diversity of green roof types. 8 refs., 2 tabs., 1 fig.

  11. Structural relationships in high temperature superconductors

    International Nuclear Information System (INIS)

    Schuller, I.K.; Segre, C.U.; Hinks, D.G.; Jorgensen, J.D.; Soderholm, L.; Beno, M.; Zhang, K.

    1987-09-01

    The recent discovery of two types of metallic copper oxide compounds which are superconducting to above 90 0 K has renewed interest in the search for new high temperature superconducting materials. It is significant that both classes of compounds, La/sub 2-x/Sr/sub x/CuO/sub 4-y/ and YBa 2 Cu 3 O/sub 7-δ/ are intimately related to the extensively studied perovskite family. Both compounds contain highly oxidized, covalently bonded Cu-O sublattices, however, they differ in geometry. In this paper we discuss the relationship of these features to the superconducting properties. 30 refs., 6 figs

  12. The significance of classical structures in quantum theories

    International Nuclear Information System (INIS)

    Lowe, M.J.

    1978-09-01

    The implications for the quantum theory of the presence of non-linear classical solutions of the equations of motion are investigated in various model systems under the headings: (1) Canonical quantisation of the soliton in lambdaphi 4 theory in two dimensions. (2) Bound for soliton masses in two dimensional field theories. (3) The canonical quantisation of a soliton like solution in the non-linear schrodinger equation. (4) The significance of the instanton classical solution in a quantum mechanical system. (U.K.)

  13. Molecular structures and functional relationships in clostridial neurotoxins.

    Science.gov (United States)

    Swaminathan, Subramanyam

    2011-12-01

    The seven serotypes of Clostridium botulinum neurotoxins (A-G) are the deadliest poison known to humans. They share significant sequence homology and hence possess similar structure-function relationships. Botulinum neurotoxins (BoNT) act via a four-step mechanism, viz., binding and internalization to neuronal cells, translocation of the catalytic domain into the cytosol and finally cleavage of one of the three soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) causing blockage of neurotransmitter release leading to flaccid paralysis. Crystal structures of three holotoxins, BoNT/A, B and E, are available to date. Although the individual domains are remarkably similar, their domain organization is different. These structures have helped in correlating the structural and functional domains. This has led to the determination of structures of individual domains and combinations of them. Crystal structures of catalytic domains of all serotypes and several binding domains are now available. The catalytic domains are zinc endopeptidases and share significant sequence and structural homology. The active site architecture and the catalytic mechanism are similar although the binding mode of individual substrates may be different, dictating substrate specificity and peptide cleavage selectivity. Crystal structures of catalytic domains with substrate peptides provide clues to specificity and selectivity unique to BoNTs. Crystal structures of the receptor domain in complex with ganglioside or the protein receptor have provided information about the binding of botulinum neurotoxin to the neuronal cell. An overview of the structure-function relationship correlating the 3D structures with biochemical and biophysical data and how they can be used for structure-based drug discovery is presented here. Journal compilation © 2011 FEBS. No claim to original US government works.

  14. The structure and significance of enterobacterial common antigen (ECA

    Directory of Open Access Journals (Sweden)

    Tomasz Kasper Goździewicz

    2015-09-01

    Full Text Available The enterobacterial common antigen (ECA is a carbohydrate-derived cell surface antigen present in all Gram-negative bacteria belonging to Enterobacteriaceae family. Biosynthetic pathways shared by ECA and LPS (endotoxin suggest close connections between these antigens. ECA occurs in three different forms: a phosphatidyl-linked linear polysaccharide anchored on the cell surface (ECAPG, a cyclic form built of 4-6 repeating units localized in the periplasm (ECACYC and as a linear polysaccharide covalently linked to LPS core oligosaccharide (ECALPS. Regardless of ECA form, poly- and oligosaccharides of ECA consist of the biological trisaccharide repeating units: →3-α-d-Fucp4NAc-(1→4-β-d-ManpNAcA-(1→4-α-d-GlcpNAc-(1→, where Fucp4NAc refers to 4-acetamido-2,4-dideoxygalactose, ManpNAcA to N-acetyl-mannosaminuronic acid and GlcpNAc to N-acetylglucosamine. ECAPG and ECALPS consisting of one unit with Fucp4NAc as a terminal sugar were also identified. The number of the studies shows its occurrence in all members of enteric bacteria with a few exceptions such as Erwinia chrysanthemi. The presence of ECA was also shown for such genera as Plesiomonas [4] and Yersinia [36], previously belonging to the Vibrionaceae and Pasteurellaceae families, respectively. It was one of the reasons to include these two taxa in the Enterobacteriaceae family. The function of ECA is not fully understood, but it was reported that its occurrence is important in resistance of bacterial cells to environmental conditions, such as bile salts in the human digestive tract. The immunogenicity of ECA seems very interesting in the fact that only sparse rough Gram-negative strains, such as Shigella sonnei phase II, Escherichia coli R1, R2, R4, K-12, and Yersinia enterocolitica O:3 are able to induce the production of specific anti-ECA antibodies. It is the effect of the ECALPS, and the evidence for the existence of such covalent linkage was provided by structural analysis of S

  15. The significance of interfamilial relationships on birth preparedness and complication readiness in Pakistan.

    Science.gov (United States)

    Ghani, Usman; Crowther, Susan; Kamal, Yasir; Wahab, Muhammad

    2018-03-29

    In the interests of improving maternal health care and survival, the issue of birth preparedness and complication readiness has been much debated and has remained a priority for the international health community. The provision of birth preparedness and complications readiness is determined by a range of different factors. The main aim of this study is to identify and measure the influence of husbands and other family relationships on birth preparedness and complications readiness in the Khyber Pakhtunkhwa province of Pakistan. This study is a cross-sectional exploratory study. Data was collected through a survey questionnaire. Logistic regression and descriptive analysis was used. Analysis indicated that the mother-in-law's role, men's and women's level of education and interfamilial relationships are still the most significant factors influencing birth preparedness and complications readiness. Of the respondents, 86% were receiving antenatal care and 76.5% were planning for the birth to take place in state-run hospitals or private obstetric and gynae clinics. The tendency to take up antenatal care in Khyber Pakhtunkhwa can mainly be credited to a mutual understanding between husband and wife and a good relationship between the woman and her mother-in-law. Highlighting the significance of these relationships has implications for ensuring birth preparedness and complications readiness. Copyright © 2018 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  16. BLAT2DOLite: An Online System for Identifying Significant Relationships between Genetic Sequences and Diseases.

    Directory of Open Access Journals (Sweden)

    Liang Cheng

    Full Text Available The significantly related diseases of sequences could play an important role in understanding the functions of these sequences. In this paper, we introduced BLAT2DOLite, an online system for annotating human genes and diseases and identifying the significant relationships between sequences and diseases. Currently, BLAT2DOLite integrates Entrez Gene database and Disease Ontology Lite (DOLite, which contain loci of gene and relationships between genes and diseases. It utilizes hypergeometric test to calculate P-values between genes and diseases of DOLite. The system can be accessed from: http://123.59.132.21:8080/BLAT2DOLite. The corresponding web service is described in: http://123.59.132.21:8080/BLAT2DOLite/BLAT2DOLiteIDMappingPort?wsdl.

  17. [Relationships between microscope structure and thermodynamic properties

    International Nuclear Information System (INIS)

    Wu, R.S.; Lee, L.L.; Cochran, D.

    1990-01-01

    This paper exhibits on the molecular level, the relationships between the microscopic structure and thermodynamic properties of dilute supercritical solutions by application of the integral equation theories for molecular distribution functions. To solve the integral equations, the authors use Baxter's Wiener-Hopf factorization of the Ornstein-Zernike equations and then apply this method to binary Lennard-Jones mixtures. A number of closure relations have been used: such as the Percus-Yevick (PY), the reference hypernetted chain (RHNC), the hybrid mean spherical approximation (HMSA), and the reference interaction-site (RISM) methods. The authors examine the microstructures of several important classes of supercritical mixtures, including the usual attractive-type and the less known repulsive-type solutions. The clustering of solvent molecules for solvent-solute structures in the attractive mixtures and, correspondingly, the solvent cavitation in the repulsive mixtures are clearly demonstrated. These are shown to be responsible for the large negative growth of the solute partial molar volumes in the attractive case and the positive growth in the repulsive case

  18. Relationship between electronic structure and radioprotective activity of some indazoles

    International Nuclear Information System (INIS)

    Sokolov, Yu.A.

    2000-01-01

    The quantum-chemical study of electronic structure of 29 indasoles with complete optimization of geometry and search of quantitative link between the established characteristics and radioprotective activity (RPA) was carried out through the MNDO method with application of multiple linear and nonlinear regression analysis and the basic component method. The equations of correlation relationship between the RPA and electronic characteristics are presented. 10 indasole structures, the forecasted RPA values whereof (survival rate, %) equal 50% and above, are selected. The statistic significance of the obtained correlation equations and their regression coefficients make it possible to conclude, that the established relationships are not accidental and are prospective for forecasting RPA of other close compounds of the indasole series [ru

  19. Relationship and significance of gait deviations associated with limb length discrepancy: A systematic review.

    Science.gov (United States)

    Khamis, Sam; Carmeli, Eli

    2017-09-01

    Controversy still exists as to the clinical significance of leg length discrepancy (LLD) in spite of the fact that further evidence has been emerging regarding the relationship between several clinical conditions and LLD. The objectives of our study were to review the available research with regard to LLD as a cause of clinically significant gait deviations, to determine if there is a relationship between the magnitude of LLD and the presence of gait deviations and to identify the most common gait deviations associated with LLD. In line with the PRISMA guidelines, a literature search was carried out throughout the Medline, CINAHL and EMBASE databases. Twelve articles met the predetermined inclusion criteria and were included in the review. Quality assessment using the Methodological Index for Non-Randomized Studies (MINORS) scale was completed for all included studies. Two main methodologies were found in 4 studies evaluating gait asymmetry in patients or healthy participants with anatomic LLD and 8 studies evaluating gait deviations while simulating LLD by employing artificial lifts of 1-5cm on healthy subjects. A significant relationship was found between anatomic LLD and gait deviation. Evidence suggests that gait deviations may occur with discrepancies of >1cm, with greater impact seen as the discrepancy increases. Compensatory strategies were found to occur in both the shorter and longer limb, throughout the lower limb. As the discrepancy increases, more compensatory strategies occur. Sagittal plane deviations seem to be the most effective deviations, although, frontal plane compensations also occur in the pelvis, hip and foot. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Perceptions of self, significant others, and teacher-child relationships in indiscriminately friendly children.

    Science.gov (United States)

    Vervoort, Eleonora; Bosmans, Guy; Doumen, Sarah; Minnis, Helen; Verschueren, Karine

    2014-11-01

    Despite increasing research on indiscriminate friendliness in children, almost no research exists on social-cognitive deficits that are supposed to underlie indiscriminately friendly behavior. In this study, we compared indiscriminately friendly children with controls regarding their perceptions of self, reliability trust in significant others, and perceptions of the teacher-child relationship. Children's perceptions were compared in two samples: a sample of 33 likely cases for disinhibited reactive attachment disorder (RAD) from special education for children with emotional and behavioral disorders (75.76% boys, Mage=8.52, 96.9% Caucasian, 33.3% and 45.5% of their mothers completed primary or secondary education, respectively) was matched on sex, age, and socio-economic status with a sample of 33 controls from general education. Children participated individually in several interviews assessing global and social self-concept, reliability trust in significant others, teacher-child relationship perceptions, and vocabulary. Parents and teachers completed a screening questionnaire for RAD and the Strengths and Difficulties Questionnaire. Likely disinhibited RAD-cases showed more indiscriminate friendliness and more problem behavior in general according to their parents and teachers than controls. Furthermore, likely RAD-cases reported a more positive global self-concept, more reliability trust in significant others, and more dependency in the teacher-child relationship than controls. The results are in line with clinical observations of indiscriminately friendly children and findings in clinical samples of maltreated or attachment disrupted children but contrast hypotheses from developmental attachment research. Further research is needed to explain the more positive perceptions of indiscriminately friendly children. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The relationship between energy consumption structure, economic structure and energy intensity in China

    International Nuclear Information System (INIS)

    Feng Taiwen; Sun Linyan; Zhang Ying

    2009-01-01

    This paper investigates the long-run equilibrium relationships, temporal dynamic relationships and causal relationships between energy consumption structure, economic structure and energy intensity in China. Time series variables over the periods from 1980 to 2006 are employed in empirical tests. Cointegration tests suggest that these three variables tend to move together in the long-run. In addition, Granger causality tests indicate that there is a unidirectional causality running from energy intensity to economic structure but not vice versa. Impulse response analysis provides reasonable evidences that one shock of the three variables will cause the periods of destabilized that followed. However, the impact of the energy consumption structure shock on energy intensity and the impact of the economic structure shock on energy consumption structure seem to be rather marginal. The findings have significant implications from the point of view of energy conservation and economic development. In order to decrease energy intensity, Chinese government must continue to reduce the proportion of coal in energy consumption, increase the utilization efficiency of coal and promote the upgrade of economic structure. Furthermore, a full analysis of factors that may relate to energy intensity (e.g. energy consumption structure, economic structure) should be conducted before making energy policies.

  2. Stress Exposure in Significant Relationships Is Associated with Lymph Node Status in Breast Cancer.

    Directory of Open Access Journals (Sweden)

    Chiara Renzi

    Full Text Available Life stress exposure may impact on health and disease. Previous literature showed that stressful life events are associated with cancer incidence, survival and mortality. In animal models, patterns of maternal care have been shown to critically affect stress sensitivity and immunity trajectories later in life, by modifying DNA methylation during critical periods early in life. However, the role of parental care in breast cancer progression and survival has only limitedly been explored. Here, we investigated whether these factors may be linked to biological prognostic variables.One hundred twenty-three women hospitalized for surgery of primary breast cancer completed a questionnaire assessing parental bonding. Stressful events throughout the life span were also assessed.We found that the absence of optimal parental relationships is significantly associated with an increased risk of lymph node involvement, adjusting for confounders, while cumulative stress in the area of sentimental relationships is borderline significantly associated with the same prognostic factor.Our results suggest that parental bonding and sentimental relations may have a role in breast cancer progression. These variables represent an important evolutionary aspect which may modulate cancer progression through psycho-physiological stress pathways and influence the immune system.

  3. Significant relationship between lifetime alcohol use disorders and suicide attempts in an Australian schizophrenia sample.

    Science.gov (United States)

    McLean, Duncan; Gladman, Beverley; Mowry, Bryan

    2012-02-01

    Suicide and attempted suicide are common in individuals with schizophrenia, and evidence exists for a link between substance use disorders and suicidality in this disorder. However, alcohol has not been consistently implicated. We examined the relationship between substance use disorders and suicide attempts in schizophrenia. We recruited a schizophrenia sample in Australia (n = 821) for genetic analyses. We analysed demographic and clinical variables, including substance use disorders, and their relationship to suicide attempts using generalised equation modelling. A significant association was identified between lifetime alcohol abuse/dependence and suicide attempts (OR = 1.66; 95% CI, 1.23 to 2.24; p = 0.001) after adjustment for potential confounders, but not between cannabis abuse/dependence and suicide attempts, nor between other illicit drug abuse/dependence and suicide attempts. Polysubstance abuse/dependence was also not implicated. These results suggest that the presence of alcohol abuse/dependence may be a risk factor for suicide attempts in individuals with schizophrenia, independent of comorbid substance abuse/dependence.

  4. Factors correlating with significant differences between X-ray structures of myoglobin

    International Nuclear Information System (INIS)

    Rashin, Alexander A.; Domagalski, Marcin J.; Zimmermann, Michael T.; Minor, Wladek; Chruszcz, Maksymilian; Jernigan, Robert L.

    2014-01-01

    Conformational differences between myoglobin structures are studied. Most structural differences in whale myoglobin beyond the uncertainty threshold can be correlated with a few specific structural factors. There are always exceptions and a search for additional factors is needed. The results might have serious implications for biological insights from conformational differences. Validation of general ideas about the origins of conformational differences in proteins is critical in order to arrive at meaningful functional insights. Here, principal component analysis (PCA) and distance difference matrices are used to validate some such ideas about the conformational differences between 291 myoglobin structures from sperm whale, horse and pig. Almost all of the horse and pig structures form compact PCA clusters with only minor coordinate differences and outliers that are easily explained. The 222 whale structures form a few dense clusters with multiple outliers. A few whale outliers with a prominent distortion of the GH loop are very similar to the cluster of horse structures, which all have a similar GH-loop distortion apparently owing to intermolecular crystal lattice hydrogen bonds to the GH loop from residues near the distal histidine His64. The variations of the GH-loop coordinates in the whale structures are likely to be owing to the observed alternative intermolecular crystal lattice bond, with the change to the GH loop distorting bonds correlated with the binding of specific ‘unusual’ ligands. Such an alternative intermolecular bond is not observed in horse myoglobins, obliterating any correlation with the ligands. Intermolecular bonds do not usually cause significant coordinate differences and cannot be validated as their universal cause. Most of the native-like whale myoglobin structure outliers can be correlated with a few specific factors. However, these factors do not always lead to coordinate differences beyond the previously determined uncertainty

  5. Factors correlating with significant differences between X-ray structures of myoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Rashin, Alexander A., E-mail: alexander-rashin@hotmail.com [BioChemComp Inc., 543 Sagamore Avenue, Teaneck, NJ 07666 (United States); Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); Domagalski, Marcin J. [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); Zimmermann, Michael T. [Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); Minor, Wladek [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); Chruszcz, Maksymilian [University of Virginia, 1340 Jefferson Park Avenue, Jordan Hall, Room 4223, Charlottesville, VA 22908 (United States); University of South Carolina, 631 Sumter Street, Columbia, SC 29208 (United States); Jernigan, Robert L. [Iowa State University, 112 Office and Lab Bldg, Ames, IA 50011-3020 (United States); BioChemComp Inc., 543 Sagamore Avenue, Teaneck, NJ 07666 (United States)

    2014-02-01

    Conformational differences between myoglobin structures are studied. Most structural differences in whale myoglobin beyond the uncertainty threshold can be correlated with a few specific structural factors. There are always exceptions and a search for additional factors is needed. The results might have serious implications for biological insights from conformational differences. Validation of general ideas about the origins of conformational differences in proteins is critical in order to arrive at meaningful functional insights. Here, principal component analysis (PCA) and distance difference matrices are used to validate some such ideas about the conformational differences between 291 myoglobin structures from sperm whale, horse and pig. Almost all of the horse and pig structures form compact PCA clusters with only minor coordinate differences and outliers that are easily explained. The 222 whale structures form a few dense clusters with multiple outliers. A few whale outliers with a prominent distortion of the GH loop are very similar to the cluster of horse structures, which all have a similar GH-loop distortion apparently owing to intermolecular crystal lattice hydrogen bonds to the GH loop from residues near the distal histidine His64. The variations of the GH-loop coordinates in the whale structures are likely to be owing to the observed alternative intermolecular crystal lattice bond, with the change to the GH loop distorting bonds correlated with the binding of specific ‘unusual’ ligands. Such an alternative intermolecular bond is not observed in horse myoglobins, obliterating any correlation with the ligands. Intermolecular bonds do not usually cause significant coordinate differences and cannot be validated as their universal cause. Most of the native-like whale myoglobin structure outliers can be correlated with a few specific factors. However, these factors do not always lead to coordinate differences beyond the previously determined uncertainty

  6. Structure Property Relationships in Organic Conjugated Systems

    OpenAIRE

    O'Neill, Luke; Lynch, Patrick; McNamara, Mary

    2005-01-01

    A series of π conjugated oligomers were studied by absorption and photoluminescence spectroscopy. A linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Sto...

  7. Structure Property Relationships in Organic Conjugated Systems

    OpenAIRE

    O'Neill, Luke

    2008-01-01

    A series of pi(п) conjugated oligomers containing 1 to 6 monomer units were studied by absorption and photoluminescence spectroscopies. The results are discussed and examined with regard to the variation of the optical properties with the increase of effective conjugation length. It was found that there was a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length. The relationships are in good agreement with the si...

  8. Significance of structure–soil–structure interaction for closely spaced structures

    International Nuclear Information System (INIS)

    Roy, Christine; Bolourchi, Said; Eggers, Daniel

    2015-01-01

    Nuclear facilities typically consist of many closely spaced structures with different sizes and depths of embedment. Seismic response of each structure could be influenced by dynamic structure–soil–structure interaction (SSSI) behavior of adjacent closely spaced structures. This paper examines the impact of SSSI on the in-structure response spectra (ISRS) and peak accelerations of a light structure adjacent to a heavy structure and of a heavy structure adjacent to a similar heavy structure for several soil cases, foundation embedment depths, and separation distances. The impacts of a heavy surface or embedded structure on adjacent ground motions were studied. The analyses demonstrated the adjacent ground motions are sensitive to foundation embedment, soil profile, response frequency, and distance from the structure. Seismic responses of a light structure located near a heavy structure are calculated either by modeling both structures subjected to free field motions, or performing a cascade analysis by considering the light structure model subjected to modified ground motions due to the heavy structure. Cascade SSSI analyses are shown to adequately account for the effect of the heavy structure on the light structure without explicitly modeling both structures together in a single analysis. To further study the influence of SSSI behavior, this paper examines dynamic response of two adjacent heavy structures and compares this response to response of a single heavy structure neglecting adjacent structures. The SSSI responses of the two heavy structures are evaluated for varying soil conditions and structure separation distances using three-dimensional linear SSI analyses and considering anti-symmetry boundary conditions. The analyses demonstrate that the SSSI response of a light or a heavy structure can be influenced by the presence of a nearby heavy structure. Although this study considers linear analysis methodology, the conclusion of SSSI influences on dynamic

  9. Evolutionary significance of seed structure in Alpinioideae (Zingiberaceae): Seed Structure in Alpinioideae

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, John C. [Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor MI (United States); Smith, Selena Y. [Department of Earth & Environmental Sciences, University of Michigan, Ann Arbor MI (United States); Museum of Paleontology, University of Michigan, Ann Arbor MI (United States); Collinson, Margaret E. [Department of Earth Sciences, Royal Holloway, University of London (United Kingdom); Leong-Škorničková, Jana [Herbarium, Singapore Botanic Gardens, National Parks Board (Singapore); Specht, Chelsea D. [Department of Plant and Microbial Biology & University and Jepson Herbaria, University of California, Berkeley CA (United States); Fife, Julie L. [Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Marone, Federica [Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Xiao, Xianghui [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Parkinson, Dilworth Y. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)

    2015-03-09

    Alpinioideae is the largest of the four subfamilies of Zingiberaceae and is widely distributed throughout the New and Old World tropics. Recent molecular studies have shown that, although Alpinioideae is a strongly supported monophyletic subfamily with two distinct tribes (Alpinieae and Riedelieae), large genera, such as Alpinia and Amomum, are polyphyletic and are in need of revision. Alpinia and Amomum have been shown to form seven and three distinct clades, respectively, but, for many of these clades, traditional vegetative and floral synapomorphies have not been found. A broad survey of seeds in Alpinioideae using light microscopy and synchrotron-based X-ray tomographic microscopy has shown that many clades have distinctive seed structures that serve as distinctive apomorphies. Tribes Riedelieae and Alpinieae can be distinguished on the basis of operculum structure, with the exception of three taxa analysed. The most significant seed characters were found to be various modifications of the micropylar and chalazal ends, the cell shape of the endotesta and exotesta, and the location of an endotestal gap. A chalazal chamber and hilar rim are reported for the first time in Zingiberaceae. In addition to characterizing clades of extant lineages, these data offer insights into the taxonomic placement of many fossil zingiberalean seeds that are critical to understanding the origin and evolution of Alpinioideae and Zingiberales as a whole.(c) 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178, 441-466..

  10. The prognostic significance and relationship with body composition of CCR7-positive cells in colorectal cancer.

    Science.gov (United States)

    Malietzis, George; Lee, Gui Han; Bernardo, David; Blakemore, Alexandra I F; Knight, Stella C; Moorghen, Morgan; Al-Hassi, Hafid O; Jenkins, John T

    2015-07-01

    The host local immune response (LIR) to cancer is a determinant of cancer outcome. Regulation of this local response is largely achieved through chemokine synthesis from the tumor microenvironment such as C-Chemokine-Receptor-7 (CCR7). We examined the LIR measured as CCR7 expression, in colorectal cancers (CRC) and explored relationships with body composition (BC) and survival. A study of paraffin-embedded tissue specimens was carried out in 116 patients with non-metastatic CRC. CCR7 expression was determined by immunohistochemistry. Analysis of computer tomography scans was used to calculate BC parameters. Survival analyses and multivariate regression models were used. High CCR7(+) cell density within the tumor stroma and at the margin was significantly associated with increased age, the presence of lymphovascular invasion, higher tumor stage, lymph node metastasis, high Klintrup-Makinen immune score, and myosteatosis. High CCR7(+) cell density in the tumor margin was significantly associated with shorter disease-free (DFS) and overall survival (OS) (P < 0.001). This was also significantly associated with shorter survival in multivariate analysis (HR = 8.87; 95%CI [2.51-31.3]; P < 0.01 for OS and HR = 4.72; 95%CI (1.24-12.9); P = 0.02 for DFS). Our results suggest that a specific immune microenvironment may be associated with altered host's BC and tumor behavior, and that CCR7 may serve as a novel prognostic biomarker. © 2015 Wiley Periodicals, Inc.

  11. CASS Ferrite and Grain Structure Relationship

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, Clayton O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Meyer, Ryan M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Diaz, Aaron A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, Michael T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-07-13

    This document summarizes the results of research conducted at Pacific Northwest National Laboratory (PNNL) to determine whether, based on experimental measurements, a correlation existed between grain structure in cast austenitic stainless steel (CASS) piping and ferrite content of the casting alloy. The motivation for this research lies in the fact that ultrasonic testing (UT) is strongly influenced by CASS grain structure; knowledge of this grain structure may help improve the ability to interpret UT responses, thereby improving the overall reliability of UT inspections of CASS components.

  12. Evolutionary Relationships Based on Cellular Structure.

    Science.gov (United States)

    Van Winkle, Lon J.

    1979-01-01

    This laboratory exercise integrates the topics of cell structure, classification of living organisms, and evolution. It is suitable for secondary or college biology courses and was used in an interdisciplinary science course for nonscience majors. (BB)

  13. Bonds or Bargains: Relationship Paradigms and Their Significance for Marital Therapy.

    Science.gov (United States)

    Johnson, Sue

    1986-01-01

    Discusses contrasting conceptual paradigms describing the nature of intimate relationships. Relationships may be viewed in terms of a rational bargain or as an emotional bond. The implications of each paradigm for the process of marital therapy and the role of bonding and attachment in adult intimacy are prescribed. Implications for marital…

  14. Family Structures, Relationships, and Housing Recovery Decisions after Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Ali Nejat

    2016-04-01

    Full Text Available Understanding of the recovery phase of a disaster cycle is still in its infancy. Recent major disasters such as Hurricane Sandy have revealed the inability of existing policies and planning to promptly restore infrastructure, residential properties, and commercial activities in affected communities. In this setting, a thorough grasp of housing recovery decisions can lead to effective post-disaster planning by policyholders and public officials. The objective of this research is to integrate vignette and survey design to study how family bonds affected rebuilding/relocating decisions after Hurricane Sandy. Multinomial logistic regression was used to investigate respondents’ family structures before Sandy and explore whether their relationships with family members changed after Sandy. The study also explores the effect of the aforementioned relationship and its changes on households’ plans to either rebuild/repair their homes or relocate. These results were compared to another multinomial logistic regression which was applied to examine the impact of familial bonds on respondents’ suggestions to a vignette family concerning rebuilding and relocating after a hurricane similar to Sandy. Results indicate that respondents who lived with family members before Sandy were less likely to plan for relocating than those who lived alone. A more detailed examination shows that this effect was driven by those who improved their relationships with family members; those who did not improve their family relationships were not significantly different from those who lived alone, when it came to rebuilding/relocation planning. Those who improved their relationships with family members were also less likely to suggest that the vignette family relocate. This study supports the general hypothesis that family bonds reduce the desire to relocate, and provides empirical evidence that family mechanisms are important for the rebuilding/relocating decision

  15. Microstructure mechanical properties relationship in bainitic structures

    International Nuclear Information System (INIS)

    Altuna, M. A.; Gutierrez, I.

    2005-01-01

    In the present work, the microstructures and their mechanical properties have been studies in different bainitic structures. therefore, different bainitic morphologies have been produced by isothermal treatments carried out at different temperatures. For these steels, 400-450 degree centigree is the optimum range of temperatures in order to obtain bainitic structures. If the Temperature is higher, perlite is also formed and if it is lower, martensite is obtained during quenching. SEM and EBSD/OIM techniques were applied in order to study the microstructure. Tensile tests were carried out for mechanical characterization. (Author) 20 refs

  16. Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures.

    Science.gov (United States)

    Dickson, E D; Hamby, D M

    2014-03-01

    The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building's radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology.

  17. Experimental shielding evaluation of the radiation protection provided by the structurally significant components of residential structures

    International Nuclear Information System (INIS)

    Dickson, E D; Hamby, D M

    2014-01-01

    The human health and environmental effects following a postulated accidental release of radioactive material to the environment have been a public and regulatory concern since the early development of nuclear technology. These postulated releases have been researched extensively to better understand the potential risks for accident mitigation and emergency planning purposes. The objective of this investigation is to provide an updated technical basis for contemporary building shielding factors for the US housing stock. Building shielding factors quantify the protection from ionising radiation provided by a certain building type. Much of the current data used to determine the quality of shielding around nuclear facilities and urban environments is based on simplistic point-kernel calculations for 1950s era suburbia and is no longer applicable to the densely populated urban environments realised today. To analyse a building’s radiation shielding properties, the ideal approach would be to subject a variety of building types to various radioactive sources and measure the radiation levels in and around the building. While this is not entirely practicable, this research analyses the shielding effectiveness of ten structurally significant US housing-stock models (walls and roofs) important for shielding against ionising radiation. The experimental data are used to benchmark computational models to calculate the shielding effectiveness of various building configurations under investigation from two types of realistic environmental source terms. Various combinations of these ten shielding models can be used to develop full-scale computational housing-unit models for building shielding factor calculations representing 69.6 million housing units (61.3%) in the United States. Results produced in this investigation provide a comparison between theory and experiment behind building shielding factor methodology. (paper)

  18. Relationship between Static Stiffness and Modal Stiffness of Structures

    Directory of Open Access Journals (Sweden)

    Tianjian Ji Tianjian Ji

    2010-02-01

    Full Text Available This paper derives the relationship between the static stiffness and modal stiffness of a structure. The static stiffness and modal stiffness are two important concepts in both structural statics and dynamics. Although both stiffnesses indicate the capacity of the structure to resist deformation, they are obtained using different methods. The former is calculated by solving the equations of equilibrium and the latter can be obtained by solving an eigenvalue problem. A mathematical relationship between the two stiffnesses was derived based on the definitions of two stiffnesses. This relationship was applicable to a linear system and the derivation of relationships does not reveal any other limitations. Verification of the relationship was given by using several examples. The relationship between the two stiffnesses demonstrated that the modal stiffness of the fundamental mode was always larger than the static stiffness of a structure if the critical point and the maximum mode value are at the same node, i.e. for simply supported beam and seven storeys building are 1.5% and 15% respectively. The relationship could be applied into real structures, where the greater the number of modes being considered, the smaller the difference between the modal stiffness and the static stiffness of a structure.

  19. Structure-activity relationships of bumetanide derivatives

    DEFF Research Database (Denmark)

    Pedersen, Kasper Lykke; Töllner, Kathrin; Römermann, Kerstin

    2015-01-01

    of diuretics such as bumetanide. Bumetanide was discovered by screening ∼5000 3-amino-5-sulfamoylbenzoic acid derivatives, long before NKCC2 was identified in the kidney. Therefore, structure-activity studies on effects of bumetanide derivatives on NKCC2 are not available. EXPERIMENTAL APPROACH: In this study......, the effect of a series of diuretically active bumetanide derivatives was investigated on human NKCC2 variant A (hNKCC2A) expressed in Xenopus laevis oocytes. KEY RESULTS: Bumetanide blocked hNKCC2A transport with an IC50 of 4 μM. There was good correlation between the diuretic potency of bumetanide and its...... of the structural requirements that determine relative potency of loop diuretics on human NKCC2 splice variants, and may lead to the discovery of novel high-ceiling diuretics....

  20. The Relationship Communication Structure - Uncertainty Avoidance

    Directory of Open Access Journals (Sweden)

    Doru Alexandru Pleşea

    2011-11-01

    Full Text Available As today’s society heads towards digitalization, the virtual environment gains a growing importance. Shaping the e-environment in accordance to the real environment in order to favour the activities and processes going to take place there requires a thorough design. However, cultural attributes of reflected inherently by design play a core part in how the information displayed on websites is perceived. The present paper aims to bring a perspective about transposing the proper communication structure into the website design, from the cultural point of view and from genders point of view, as it resulted from a research of Romanian students from Bucharest Academy of Economic Studies

  1. Quantitative Structure-Activity Relationship Analysis of the ...

    African Journals Online (AJOL)

    Erah

    Quantitative Structure-Activity Relationship Analysis of the Anticonvulsant ... Two types of molecular descriptors, including the 2D autocorrelation ..... It is based on the simulation of natural .... clustering anticonvulsant, antidepressant, and.

  2. The Ghosts of Acetylcholine : structure-activity relationships of ...

    African Journals Online (AJOL)

    The Ghosts of Acetylcholine : structure-activity relationships of muscle relaxants : registrar communication. ... AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

  3. Comparative genomics of the relationship between gene structure and expression

    NARCIS (Netherlands)

    Ren, X.

    2006-01-01

    The relationship between the structure of genes and their expression is a relatively new aspect of genome organization and regulation. With more genome sequences and expression data becoming available, bioinformatics approaches can help the further elucidation of the relationships between gene

  4. Structure-Property Relationships in Polycyanurate / Graphene Networks

    Science.gov (United States)

    2015-12-12

    Briefing Charts 3. DATES COVERED (From - To) 17 Nov 2015 – 12 Dec 2015 4. TITLE AND SUBTITLE Structure-Property Relationships in Polycyanurate...ANSI Std. 239.18 1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Structure-Property Relationships in...the attractive processing characteristics of LECy are retained in graphene oxide / LECy mixtures. Impurities, such as aryl phenols and transition metals

  5. Structure-Function Relationships of Ferroelectric Polymers.

    Science.gov (United States)

    Pavlopoulou, Eleni; Maiz, Jon; Spampinato, Nicoletta; Maglione, Mario; Hadziioannou, Georges

    Poly(vinylidene fluoride), PVDF, and its copolymers with trifluoroethylene, P(VDF-co-TrFE) have been long appreciated for their excellent ferroelectric properties. Although they have been mainly studied in the 80s and 90s, understanding their performance is still lacking. Yet the increasing use of P(VDF-co-TrFE) thin films in organic electronic devices during the last ten years revives the need for apprehending the function of these materials. In this work we investigate the structure of P(VDF-co-TrFE) films and correlate it to their ferroelectric properties. Our results show that ferroelectric performance is solely driven by the fraction of polymer that has been crystallized in the ferroelectric phases of PVDF. The relations between remnant polarization, coercive field and dipole switching rate of P(VDF-co-TrFE) with the ferroelectric crystallinity are demonstrated. The French Research Agency (ANR), the Aquitaine Region, Arkema and STMicroelectronics are kindly acknowledged for financial support.

  6. Relationship between obesity and the risk of clinically significant depression: Mendelian randomisation study.

    LENUS (Irish Health Repository)

    Hung, Chi-Fa

    2014-07-01

    Obesity has been shown to be associated with depression and it has been suggested that higher body mass index (BMI) increases the risk of depression and other common mental disorders. However, the causal relationship remains unclear and Mendelian randomisation, a form of instrumental variable analysis, has recently been employed to attempt to resolve this issue.

  7. Integrative Genomics: Quantifying significance of phenotype-genotype relationships from multiple sources of high-throughput data

    Directory of Open Access Journals (Sweden)

    Eric eGamazon

    2013-05-01

    Full Text Available Given recent advances in the generation of high-throughput data such as whole genome genetic variation and transcriptome expression, it is critical to come up with novel methods to integrate these heterogeneous datasets and to assess the significance of identified phenotype-genotype relationships. Recent studies show that genome-wide association findings are likely to fall in loci with gene regulatory effects such as expression quantitative trait loci (eQTLs, demonstrating the utility of such integrative approaches. When genotype and gene expression data are available on the same individuals, we developed methods wherein top phenotype-associated genetic variants are prioritized if they are associated, as eQTLs, with gene expression traits that are themselves associated with the phenotype. Yet there has been no method to determine an overall p-value for the findings that arise specifically from the integrative nature of the approach. We propose a computationally feasible permutation method that accounts for the assimilative nature of the method and the correlation structure among gene expression traits and among genotypes. We apply the method to data from a study of cellular sensitivity to etoposide, one of the most widely used chemotherapeutic drugs. To our knowledge, this study is the first statistically sound quantification of the significance of the genotype-phenotype relationships resulting from applying an integrative approach. This method can be easily extended to cases in which gene expression data are replaced by other molecular phenotypes of interest, e.g., microRNA or proteomic data. This study has important implications for studies seeking to expand on genetic association studies by the use of omics data. Finally, we provide an R code to compute the empirical FDR when p-values for the observed and simulated phenotypes are available.

  8. Significance of Operating Environment in Condition Monitoring of Large Civil Structures

    OpenAIRE

    Alampalli, Sreenivas

    1999-01-01

    Success of remote long-term condition monitoring of large civil structures and developing calibrated analytical models for damage detection, depend significantly on establishing accurate baseline signatures and their sensitivity. Most studies reported in the literature concentrated on the effect of structural damage on modal parameters without emphasis on reliability of modal parameters. Thus, a field bridge structure was studied for the significance of operating conditions in relation to bas...

  9. Research on structure-alteration zone related to uranium mineralization and its exploration significance

    International Nuclear Information System (INIS)

    Huang Xianfang; Liu Dechang; Ye Fawang; Dong Xiuzhen; Yang Xu Zhang Hongguang

    2008-01-01

    The paper is focused on recommending geological characteristics of structure-alteration zone which is found from image interpretation in Bashibulake District, north of Tarim Basin, expounding remote sensing information enhancement and extraction technique, analyzing image feature, genetic mechanism and discussing the relationship between uranium mineralization and structure-alteration zone. A new discovery is raised through applying remote sensing information analysis and geologic analysis, that is, the uranium deposits in Bashibulake District are controlled by structure-alteration zone. The new understanding provides a new view point for reconsidering main controlling factors and uranium mineralization distribution in the area. It is helpful for further reconnaissance and exploration in the area. (authors)

  10. Significant others and contingencies of self-worth: activation and consequences of relationship-specific contingencies of self-worth.

    Science.gov (United States)

    Horberg, E J; Chen, Serena

    2010-01-01

    Three studies tested the activation and consequences of contingencies of self-worth associated with specific significant others, that is, relationship-specific contingencies of self-worth. The results showed that activating the mental representation of a significant other with whom one strongly desires closeness led participants to stake their self-esteem in domains in which the significant other wanted them to excel. This was shown in terms of self-reported contingencies of self-worth (Study 1), in terms of self-worth after receiving feedback on a successful or unsatisfactory performance in a relationship-specific contingency domain (Study 2), and in terms of feelings of reduced self-worth after thinking about a failure in a relationship-specific contingency domain (Study 3). Across studies, a variety of contingency domains were examined. Furthermore, Study 3 showed that failing in an activated relationship-specific contingency domain had negative implications for current feelings of closeness and acceptance in the significant-other relationship. Overall, the findings suggest that people's contingencies of self-worth depend on the social situation and that performance in relationship-specific contingency domains can influence people's perceptions of their relationships.

  11. Tools to Understand Structural Property Relationships for Wood Cell Walls

    Science.gov (United States)

    Joseph E. Jakes; Daniel J. Yelle; Charles R. Frihart

    2011-01-01

    Understanding structure-property relationships for wood cell walls has been hindered by the complex polymeric structures comprising these cell walls and the difficulty in assessing meaningful mechanical property measurements of individual cell walls. To help overcome these hindrances, we have developed two experimental methods: 1) two-dimensional solution state nuclear...

  12. Syntheses and absorption-structure relationships of some new ...

    Indian Academy of Sciences (India)

    New biheterocyclic compound was synthesized as starting material to prepare new photosensitizers mono-, tri-, substituted tri-, azadimethine and mixed cyanine dyes. Absorption-structure relationship of the synthesized cyanine dyes were determined by studying their electronic spectral behaviour in ethanol. The structure of ...

  13. Significance of Operating Environment in Condition Monitoring of Large Civil Structures

    Directory of Open Access Journals (Sweden)

    Sreenivas Alampalli

    1999-01-01

    Full Text Available Success of remote long-term condition monitoring of large civil structures and developing calibrated analytical models for damage detection, depend significantly on establishing accurate baseline signatures and their sensitivity. Most studies reported in the literature concentrated on the effect of structural damage on modal parameters without emphasis on reliability of modal parameters. Thus, a field bridge structure was studied for the significance of operating conditions in relation to baseline signatures. Results indicate that in practice, civil structures should be monitored for at least one full cycle of in-service environmental changes before establishing baselines for condition monitoring or calibrating finite-element models. Boundary conditions deserve special attention.

  14. Polonium-210 and lead-210 in marine organisms: allometric relationships and their significance

    International Nuclear Information System (INIS)

    Cherry, R.D.; Heyraud, M.

    1991-01-01

    Allometric relationships which indicate that Po-210 concentrations in marine organisms decrease with increasing organism mass have been reported previously in a few taxa. We report here the results of a study of nearly 400 data covering nine taxa of marine organisms. The data for each taxon are fitted to the allometric equation log Q = log a + b log M, where Q is the Po-210 concentration (mBq/g dry mass) and M is the dry mass per individual (g). The weighted mean of the nine Po-210 slopes is -0.24 ± 0.05, and of the eight Pb-210 slopes is -0.22 ± 0.05. These values are close to the slope of -0.25 frequently found in mass-specific allometric relationships in biology; an association between radionuclide concentration and food ingestion rate is indicated. The intertaxon variations in the intercept log a are large, nearly two orders of magnitude for Po-210, a fact which almost certainly reflects intertaxon differences in diet and/or assimilation. Within taxa, sub-groupings of the Po-210 data are found; these are discussed and an attempt is made to classify them statistically for the data as a whole. (Author)

  15. Political significance of the CTBT (History, status, relationship with the Pelindaba Treaty, etc.)

    International Nuclear Information System (INIS)

    Onanga-Anyanga, P.

    1999-01-01

    This presentation deals with historical overview, negotiations on CTBT and its adoption, status and verification system of the Treaty, political significance of CTBT and its significance for States signatories in Africa. Separate chapters are devoted to the African region, CTBT Pelindaba Treaty and cooperative prospects and relevance of the CTBT for Africa

  16. [Cryptogenic stroke - patent foramen ovale - migraine with aura: incidental triad or significant relationship? Part II].

    Science.gov (United States)

    Łukasik, Maria; Kozubski, Wojciech

    2012-01-01

    In the second part of the paper, we discuss the relationship between migraine with aura and either patent foramen ovale (PFO) or stroke. The results of the studies suggest that PFO with right-to-left shunt is more prevalent among patients suffering from migraine with aura. Moreover, migraine with aura is a risk factor for ischaemic stroke in women and the risk increases when they have additional vascular risk factors such as taking oral contraception and smoking. However, the pathophysiology of these phenomena remains hypothetical. The most frequently reported theory suggests paradoxical embolism as a mechanism of the above-mentioned pathologies. In this paper we compare the pros and cons of the general theories. We discuss the percutaneous closure of PFO in patients with migraine, regarding the benefit/risk ratio.

  17. A Historical Analysis of the Relationship of Faith and Science and its Significance within Education

    Science.gov (United States)

    Yegge, John G.

    Science curriculum and pedagogy are at the center of a centuries-long debate concerning the appropriate relationship of faith and science. The difficulties that science educators face seem to be based in misinformation about the historical roots of this conflict. To address that conflict, the goals of this research were to separate myth from reality and to provide a necessary context to the current tensions that are disrupting science pedagogy and curriculum content within American public schools. Working within a theoretical framework of historical literacy, this qualitative, historical analysis was a comprehensive examination of the relationship of faith and science from ancient times through the Renascence to the emergence and development of Darwinism. The historical approach methodology was utilized as a means to document the systematic examination of past events, in order to illuminate and interpret the meaning of those events. The historical record revealed that science and religion are not necessarily incompatible and that the early Christian religion provided a fertile environment in which modern science could emerge. Also noted were many instances where the record was inconsistent with what educators have commonly taught as historical fact. Finally, the complex sources of tension between modern fundamentalist Christianity and Darwinism, which has appeared as a flashpoint in public discourse within science education, were examined in depth. Based on this analysis, the study includes recommendations for educators in their approach to addressing these challenges and teaching science. This analysis can produce positive social change for educators and their students, as this information is advanced as a means to enhance historical literacy among educators and their students.

  18. V-amylose structural characteristics, methods of preparation, significance, and potential applications

    CSIR Research Space (South Africa)

    Obiro, WC

    2012-02-01

    Full Text Available , and postprandial hyperglycaemia in diabetics. Various aspects of V-amylose structure, methods of preparation, factors that affect its formation, and the significance and potential applications of the V-amylose complexes are reviewed....

  19. The Relationship between Motivational Structure, Mental Health and Attitude to Opiate Substances in University Students

    Directory of Open Access Journals (Sweden)

    Ali akbar Soliemanian

    2012-02-01

    Full Text Available Introduction: This study was carried out with the aim of evaluating the relationship between motivational structure, mental health and attitude to opiate substances in a sample of North-Khorasan's university students. Method: In a descriptive cross-sectional study, 400 participants (200 males and 200 females were selected by stratified random sampling of three universities of north khorasan. All participants completed the SCL-90-R, Personal Concerns Inventory and Attitude to Opiate Substances questionnaire. Findings: The results revealed that there was a significant difference between participants with maladaptive motivational structure and adaptive motivational structure on GSI and subscales of SCL-90-R. In addition, the comparison of two groups showed that participants with maladaptive motivational structure had significant more positive attitude to opiate Substances than participants with adaptive motivational structure. Conclusion: There is a significant relationship between motivational structure, mental health and attitude to opiate substances.

  20. Performance evaluation recommendations of nuclear power plants outdoor significant civil structures earthquake resistance. Performance evaluation examples

    International Nuclear Information System (INIS)

    2005-06-01

    The Japan Society of Civil Engineers has updated performance evaluation recommendations of nuclear power plants outdoor significant civil structures earthquake resistance in June 2005. Based on experimental and analytical considerations, analytical seismic models of soils for underground structures, effects of vertical motions on time-history dynamic analysis and shear fracture of reinforced concretes by cyclic loadings have been incorporated in new recommendations. This document shows outdoor civil structures earthquake resistance and endurance performance evaluation examples based on revised recommendations. (T. Tanaka)

  1. Evidence for the functional significance of diazotroph community structure in soil.

    Science.gov (United States)

    Hsu, Shi-Fang; Buckley, Daniel H

    2009-01-01

    Microbial ecologists continue to seek a greater understanding of the factors that govern the ecological significance of microbial community structure. Changes in community structure have been shown to have functional significance for processes that are mediated by a narrow spectrum of organisms, such as nitrification and denitrification, but in some cases, functional redundancy in the community seems to buffer microbial ecosystem processes. The functional significance of microbial community structure is frequently obscured by environmental variation and is hard to detect in short-term experiments. We examine the functional significance of free-living diazotrophs in a replicated long-term tillage experiment in which extraneous variation is minimized and N-fixation rates can be related to soil characteristics and diazotroph community structure. Soil characteristics were found to be primarily impacted by tillage management, whereas N-fixation rates and diazotroph community structure were impacted by both biomass management practices and interactions between tillage and biomass management. The data suggest that the variation in diazotroph community structure has a greater impact on N-fixation rates than do soil characteristics at the site. N-fixation rates displayed a saturating response to increases in diazotroph community diversity. These results show that the changes in the community structure of free-living diazotrophs in soils can have ecological significance and suggest that this response is related to a change in community diversity.

  2. [The significance of psychodynamic relationship factors for psychopathogenesis in childhood Nazi persecution].

    Science.gov (United States)

    Bunk, D; Eggers, C

    1993-02-01

    This study focuses on psychiatric disorders following extreme traumatisation experienced by children born during the Holocaust in World War II. According to numerous epidemiological investigations and case studies on survivors who lived through the Holocaust as children or in adulthood, these traumatic experiences are associated with a higher risk for various psychiatric disturbances during the entire life span. Besides the extreme psychological and physical distress during persecution and following traumatisation (parent-child-separation, discrimination while living in other countries) the coping with the trauma and the development of autonomy and ego-strength is additionally impaired by the specific psychodynamics of families with psychologically altered and disturbed parents. What sort of psychodynamic parent-child relationships developed during traumatisation and after the war in subjects currently suffering from chronic impairment of mental health? Retrospective analysis of 22 cases with applications for pensions of invalids evaluated by diagnostic categories. The implicit pressure on the children to be sensitive to the needs of their deprived parents places a sense of guilt on their attempts to develop autonomy. The parents were experienced as restrictive or overprotective on the one hand or liable to be rejected or to be intolerant on the other. The suffering and trauma continues to be perceived in family communication to the extent that coping with loss of relatives and the development of independence are impaired. The results are discussed critically in terms of current procedures for expertise on pension applications.

  3. Mediational Significance of PTSD in the Relationship of Sexual Trauma and Eating Disorders

    Science.gov (United States)

    Holzer, Sarah R.; Uppala, Saritha; Wonderlich, Stephen A.; Crosby, Ross D.; Simonich, Heather

    2008-01-01

    Objective: To examine the mediational significance of posttraumatic stress disorder (PTSD) and the development of eating disorder symptomatology following sexually traumatic experiences. Method: Seventy-one victims of sexual trauma and 25 control subjects completed interviews and questionnaires assessing eating disorder psychopathology and…

  4. Functional significance and structure–activity relationship of food-derived α-glucosidase inhibitors

    NARCIS (Netherlands)

    Stefano, Di Elisa; Oliviero, Teresa; Udenigwe, Chibuike C.

    2018-01-01

    The ageing population, together with unhealthy diets, physical inactivity and obesity are the main drivers of the increased prevalence of Type 2 diabetes mellitus (T2DM). Apart from pharmacological treatments, the food industries can play a significant role in the management of T2DM. One of the main

  5. Food structure: Its formation and relationships with other properties.

    Science.gov (United States)

    Joardder, Mohammad U H; Kumar, Chandan; Karim, M A

    2017-04-13

    Food materials are complex in nature as it has heterogeneous, amorphous, hygroscopic and porous properties. During processing, microstructure of food materials changes which significantly affects other properties of food. An appropriate understanding of the microstructure of the raw food material and its evolution during processing is critical in order to understand and accurately describe dehydration processes and quality anticipation. This review critically assesses the factors that influence the modification of microstructure in the course of drying of fruits and vegetables. The effect of simultaneous heat and mass transfer on microstructure in various drying methods is investigated. Effects of changes in microstructure on other functional properties of dried foods are discussed. After an extensive review of the literature, it is found that development of food structure significantly depends on fresh food properties and process parameters. Also, modification of microstructure influences the other properties of final product. An enhanced understanding of the relationships between food microstructure, drying process parameters and final product quality will facilitate the energy efficient optimum design of the food processor in order to achieve high-quality food.

  6. Significant positive relationship between serum magnesium and muscle quality in maintenance hemodialysis patients.

    Science.gov (United States)

    Okazaki, Hisanori; Ishimura, Eiji; Okuno, Senji; Norimine, Kyoko; Yamakawa, Kenjiro; Yamakawa, Tomoyuki; Shoji, Shigeichi; Nishizawa, Yoshiki; Inaba, Masaaki

    2013-01-01

    Serum magnesium (Mg) levels have been associated with muscle performance in the general population. We hypothesized that serum Mg would be associated with muscle quality in hemodialysis patients. A total of 310 patients were examined (age: 58 ± 12 years, hemodialysis duration: 6.4 ± 6.0 years, 60.6% men, and 36.1% diabetics). Arm lean mass was measured by dual energy X-ray absorptiometry (DXA) on the dominant side. Arm muscle quality was defined as the ratio of the handgrip strength to the arm lean mass of the same side (kg/kg). Serum Mg was 1.15 ± 0.16 mmol/L (2.8 ± 0.4 mg/dL), being higher than the reference range of normal subjects. There was a significant negative correlation between muscle quality and age (r = -0.326, p<0.0001) and duration of hemodialysis (r = -0.253, p<0.0001). The muscle quality of the diabetics was significantly lower than that of the non-diabetics (p<0.001). There was a significant, positive correlation between muscle quality and serum Mg (r = 0.118, p<0.05), but not serum calcium or phosphate. In multiple regression analysis, age, gender, hemodialysis duration, diabetes, and serum Mg (β = 0.129, p<0.05) were significantly and independently associated with muscle quality (R(2) = 0.298, p<0.0001). These results demonstrated that a lower serum Mg concentration was significantly associated with poor muscle quality in hemodialysis patients. Further studies are needed to explore the mechanism by which lower serum Mg affects muscle quality.

  7. The significant relationships between hormonal growth pattern parameters in children with chronic liver disease

    International Nuclear Information System (INIS)

    Ayad, S.K.

    2009-01-01

    Present study was undertaken to investigate the disturbance in GH. IGF-I and IGFBP-3 axis by evaluating their levels in serum of children with chronic liver disease. twenty-two under normal growth children suffering from cholestasis and chronic viral hepatitis B or C (3-7 years) with mean value (5.05± 1.18 years) compared with twenty healthy children with mean age value (5.07+ 1.37 years) served as control. the malnourished children were classified into 2 groups (l) included 8 cholestatic children and ll: included 14 children with chronic viral hepatitis (HBV or HCV).the biochemical analysis for lover disease as serum alanine aminotransferase (ALT),aspartate aminotransferase (ASTt), alkaline phosphatase (ALP), γ-glutamyl transferase ( γ-GT), total bilirubin, total protein (P), total albumin (A), and prothrombin concentration were performed by colorimetric technique. serum growth hormone (GH), insulin -like growth factor-l (IGF-l) and insulin -like growth factor binding protein- 3 (IGFBP-3) were estimated by radioisotope technique as marker for growth. the biochemical results showed highly significant increases (P< 0.01) in ALT, AST, ALP, γ-GT and total bilirubin respectively in both malnourished groups with chronic liver disease when matched to that of control . total protein , total albumin and prothrombin concentration recorded highly significant decreases (P<0.001) particularly in GR.ll when compared with healthy children . total protein showed non-significant difference in gr.l when compared to control. GH level showed highly significant increases (P<0.01), while IGF-l and IGFBP-3 reported highly significant reduction (P<0.001) in both manourished groups when compared to the normal growth children . the elevation of GH level and reduction of both IGF-l and IGFBP-3 levels were more prominent in children with chronic viral hepatitis than cholestatic children

  8. Combining Theoretical Perspectives on the Organizational Structure-Performance Relationship

    Directory of Open Access Journals (Sweden)

    Starling David Hunter

    2015-08-01

    Full Text Available Much of the literature linking organization structure to performance falls into two broad research streams. One stream concerns formal structure – the hierarchy of authority or reporting relationships as well as the degree of standardization, formalization, specialization, etc. The impact of formal structure and other elements of organization design on performance is typically contingent on factors such as strategic orientation, task characteristics, and environmental conditions. The other research stream focuses on informal structure – a network of interpersonal and intra-organizational relationships. Properties of informal structure are typically shown to have a more direct (less contingent impact on organizational performance. Despite these pronounced differences in the conceptualization of organization structure, considerable overlap and complementarity exist between the two research streams. In this article, I compare and contrast a pair of exemplars from each stream – the information processing perspective and the social network perspective – with respect to their conceptualizations of organization structure and its relationship to performance. Several recommendations for future research that combines the two approaches are offered.

  9. Intrapartum caesarean rates differ significantly between ethnic groups--relationship to induction.

    LENUS (Irish Health Repository)

    Ismail, Khadijah I

    2012-01-31

    OBJECTIVE: Given international variation in obstetric practices and outcomes, comparison of labour outcomes in different ethnic groups could provide important information regarding the underlying reasons for rising caesarean delivery rates. Increasing numbers of women from Eastern European countries are now delivering in Irish maternity hospitals. We compared labour outcomes between Irish and Eastern European (EE) women in a large tertiary referral center. STUDY DESIGN: This was a prospective consecutive cohort study encompassing a single calendar year. The cohort comprised 5550 Irish and 867 EE women delivered in a single institution in 2009. Women who had multiple pregnancies, breech presentation, and elective or pre-labour caesarean sections (CS) were excluded. Data obtained from birth registers included maternal age, nationality, parity, gestation, onset of labour, mode of delivery and birth weight. RESULTS: The overall intrapartum CS rate was 11.4% and was significantly higher in Irish compared to EE women (11.8% vs. 8.8%; p=0.008). The proportion of primiparas was lower in Irish compared to EE women (44.8% vs. 63.6%; p<0.0001). The intrapartum CS rate was almost doubled in Irish compared to EE primiparas (20.7% vs. 11.0%; p<0.0001). Analysis of primiparas according to labour onset revealed a higher intrapartum CS rate in Irish primiparas in both spontaneous (13.5% vs. 7.2%; p<0.0001) and induced labour (29.5% vs. 19.3%; p=0.005). Irish women were older with 19.7% of primiparas aged more than 35, compared to 1.6% of EE women (p<0.0001). The primigravid CS rate in Irish women was significantly higher in women aged 35 years or older compared women aged less than 35 (30.6% vs. 18.3%; p<0.0001) consistent in both spontaneous and induced labour. The primiparous induction rate was 45.4% in Irish women compared to 32% in EE women, and more Irish women were induced before 41 weeks gestation. CONCLUSION: The results highlight that primigravid intrapartum CS rates were

  10. Structural Diversity and Close Interracial Relationships in College

    Science.gov (United States)

    Bowman, Nicholas A.

    2012-01-01

    Recent legal and political actions have challenged the use of race-conscious college admissions policies. Earlier research offers mixed evidence about the link between an institution's racial/ethnic composition (i.e., structural diversity) and the formation of close interracial relationships, so the present study examines this topic directly for…

  11. Relationships between structural complexity, coral traits, and reef fish assemblages

    Science.gov (United States)

    Darling, Emily S.; Graham, Nicholas A. J.; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.; Pratchett, Morgan S.; Wilson, Shaun K.

    2017-06-01

    With the ongoing loss of coral cover and the associated flattening of reef architecture, understanding the links between coral habitat and reef fishes is of critical importance. Here, we investigate whether considering coral traits and functional diversity provides new insights into the relationship between structural complexity and reef fish communities, and whether coral traits and community composition can predict structural complexity. Across 157 sites in Seychelles, Maldives, the Chagos Archipelago, and Australia's Great Barrier Reef, we find that structural complexity and reef zone are the strongest and most consistent predictors of reef fish abundance, biomass, species richness, and trophic structure. However, coral traits, diversity, and life histories provided additional predictive power for models of reef fish assemblages, and were key drivers of structural complexity. Our findings highlight that reef complexity relies on living corals—with different traits and life histories—continuing to build carbonate skeletons, and that these nuanced relationships between coral assemblages and habitat complexity can affect the structure of reef fish assemblages. Seascape-level estimates of structural complexity are rapid and cost effective with important implications for the structure and function of fish assemblages, and should be incorporated into monitoring programs.

  12. Croatian banking sector research: relationship between ownership structure, concentration, owners’ type and bank performance

    Directory of Open Access Journals (Sweden)

    Igor Tomičić

    2012-12-01

    Full Text Available Banks are important financial intermediaries of any national economy, and corporate governance has an important role in banking sector; especially due to processes of the globalization and the internationalization, and also because of the sensitivity of the activities between the interest groups. The objective of this paper is to examine the relationship between ownership structure, concentration, owners’ type and bank performance. The authors made a research of banks' ownership structure using publicly available data. Using statistical tools authors discovered relationships between bank ownership structure and bank performance indicators (average asset, total asset, average equity, profit (loss before taxes, profit (loss after taxes, ROAA, ROAE. Further they discuss the relationships between ownership structure and a number of consequences for the bank performance. The authors discovered significant correlation between bank ownership structure and performance indicators variables that are described in the paper.

  13. Performance evaluation recommendations and manuals of nuclear power plants outdoor significant civil structures earthquake resistance

    International Nuclear Information System (INIS)

    2005-06-01

    Performance evaluation recommendations and manuals of nuclear power plants outdoor significant civil structures earthquake resistance have been updated in June 2005 by the Japan Society of Civil Engineers. Based on experimental and analytical considerations on the recommendations of May 2002, analytical seismic models of soils for underground structures, effects of vertical motions on time-history dynamic analysis and shear fracture of reinforced concretes by cyclic loadings have been evaluated and incorporated in new recommendations. (T. Tanaka)

  14. Performance evaluation recommendations of nuclear power plants outdoor significant civil structures earthquake resistance. Technical documentation

    International Nuclear Information System (INIS)

    2005-06-01

    The Japan Society of Civil Engineers has updated performance evaluation recommendations of nuclear power plants outdoor significant civil structures earthquake resistance in June 2005. Experimental and analytical considerations on the seismic effects evaluation criteria, such as analytical seismic models of soils for underground structures, effects of vertical motions on time-history dynamic analysis and shear fracture of reinforced concretes by cyclic loadings, were shown in this document and incorporated in new recommendations. (T. Tanaka)

  15. Structure-activity relationship studies of citalopram derivatives

    DEFF Research Database (Denmark)

    Larsen, M Andreas B; Plenge, Per; Andersen, Jacob

    2016-01-01

    towards the S2 site. EXPERIMENTAL APPROACH: We performed a systematic structure-activity relationship study based on the scaffold of citalopram and the structurally closely related congener, talopram, that shows low-affinity S1 binding in SERT. The role of the four chemical substituents, which distinguish...... citalopram from talopram in conferring selectivity towards the S1 and S2 site, respectively, was assessed by determining the binding of 14 citalopram/talopram analogous to the S1 and S2 binding sites in SERT using membranes of COS7 cells transiently expressing SERT. KEY RESULTS: The structure-activity...

  16. Uncovering the structure-function relationship in spider silk

    Science.gov (United States)

    Yarger, Jeffery L.; Cherry, Brian R.; van der Vaart, Arjan

    2018-03-01

    All spiders produce protein-based biopolymer fibres that we call silk. The most studied of these silks is spider dragline silk, which is very tough and relatively abundant compared with other types of spider silks. Considerable research has been devoted to understanding the relationship between the molecular structure and mechanical properties of spider dragline silks. In this Review, we overview experimental and computational studies that have provided a wealth of detail at the molecular level on the highly conserved repetitive core and terminal regions of spider dragline silk. We also discuss the role of the nanocrystalline β-sheets and amorphous regions in determining the properties of spider silk fibres, endowing them with strength and elasticity. Additionally, we outline imaging techniques and modelling studies that elucidate the importance of the hierarchical structure of silk fibres at the molecular level. These insights into structure-function relationships can guide the reverse engineering of spider silk to enable the production of superior synthetic fibres.

  17. Finding the most significant common sequence and structure motifs in a set of RNA sequences

    DEFF Research Database (Denmark)

    Gorodkin, Jan; Heyer, L.J.; Stormo, G.D.

    1997-01-01

    We present a computational scheme to locally align a collection of RNA sequences using sequence and structure constraints, In addition, the method searches for the resulting alignments with the most significant common motifs, among all possible collections, The first part utilizes a simplified...

  18. [Volunteer satisfaction: Internal structure and relationship with permanence in organizations].

    Science.gov (United States)

    Vecina Jiménez, M L; Chacón Fuertes, Fernando; Sueiro Abad, Manuel J

    2009-02-01

    Volunteer satisfaction: Internal structure and relationship with permanence in organizations. The concept of satisfaction is considered theoretically relevant in practically all the studies that have investigated the factors that influence the permanence of volunteer participation in organizations. However, the practical results are not conclusive, perhaps due to the wide range of ways in which the concept is understood and measured. The object of this study is: to analyse the internal structure of satisfaction and to verify its relationship with volunteer duration in organizations. The results of the factor analysis yield a three-factor structure: Satisfaction with the management of the organization, Satisfaction with the tasks, Satisfaction of motivations. The three factors allow us to differentiate between individuals who remain in the organization for a period of 12 consecutive months, and those who leave earlier. The results of structural equation model analysis show that the relationship between satisfaction and the length of time that volunteers stay with the organization is affected by the intention to remain.

  19. Bank Image Structure: The Relationship to Consumer Behaviour

    Directory of Open Access Journals (Sweden)

    Lukasova Ruzena

    2014-03-01

    Full Text Available This paper presents the results of a study of the relationship between the bank image, its structure as a reflection in the minds of individuals and behavioural tendencies in relation to banks. Attitudinal scales were used to identify the contents of the particular banks’ image. The structure of the image was identified by means of factor analysis. The study found that the respondents’ behavioural tendencies, i.e. their willingness to be a client of or to recommend a particular bank, are related to different content components of particular banks and mainly to respondents’ needs. Based on the results, the study identifies the danger that the results of the bank image analysis can be misinterpreted if the respondents’ relationship to the bank is underestimated.

  20. Structuring strategy and relationships in North American gas markets

    International Nuclear Information System (INIS)

    Fisher, J.

    1998-01-01

    Duke Energy's experience in strategy development and structuring relationships with other companies were described. Included was a description of their partnership with PanEnergy and Mobil and a merger between PanEnergy and Duke. In developing their growth strategy, Duke Energy was guided by the following considerations: (1) an assessment of the market, (2) the identification of opportunities, (3) a self-assessment, (4) the establishment of goals, and (5) determining strategic alternatives. The advantages and disadvantages of different structuring relationships were reviewed. Duke Energy's approach to Ontario's residential market and their agreement with Alliance Gas Management were also discussed. The goal of the Alliance Gas management agreement was to simplify Alliance's wholesale gas supply management needs and to allow Alliance access to diverse gas supplies. figs

  1. Super-resolution structure of DNA significantly differs in buccal cells of controls and Alzheimer's patients.

    Science.gov (United States)

    Garcia, Angeles; Huang, David; Righolt, Amanda; Righolt, Christiaan; Kalaw, Maria Carmela; Mathur, Shubha; McAvoy, Elizabeth; Anderson, James; Luedke, Angela; Itorralba, Justine; Mai, Sabine

    2017-09-01

    The advent of super-resolution microscopy allowed for new insights into cellular and physiological processes of normal and diseased cells. In this study, we report for the first time on the super-resolved DNA structure of buccal cells from patients with Alzheimer's disease (AD) versus age- and gender-matched healthy, non-caregiver controls. In this super-resolution study cohort of 74 participants, buccal cells were collected and their spatial DNA organization in the nucleus examined by 3D Structured Illumination Microscopy (3D-SIM). Quantitation of the super-resolution DNA structure revealed that the nuclear super-resolution DNA structure of individuals with AD significantly differs from that of their controls (p structure of AD significantly differs in mild, moderate, and severe disease with respect to the DNA-containing and DNA-free/poor spaces. We conclude that whole genome remodeling is a feature of buccal cells in AD. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

  2. Significance of Shear Wall in Multi-Storey Structure With Seismic Analysis

    Science.gov (United States)

    Bongilwar, Rajat; Harne, V. R.; Chopade, Aditya

    2018-03-01

    In past decades, shear walls are one of the most appropriate and important structural component in multi-storied building. Therefore, it would be very interesting to study the structural response and their systems in multi-storied structure. Shear walls contribute the stiffness and strength during earthquakes which are often neglected during design of structure and construction. This study shows the effect of shear walls which significantly affect the vulnerability of structures. In order to test this hypothesis, G+8 storey building was considered with and without shear walls and analyzed for various parameters like base shear, storey drift ratio, lateral displacement, bending moment and shear force. Significance of shear wall has been studied with the help of two models. First model is without shear wall i.e. bare frame and other another model is with shear wall considering opening also in it. For modeling and analysis of both the models, FEM based software ETABS 2016 were used. The analysis of all models was done using Equivalent static method. The comparison of results has been done based on same parameters like base shear, storey drift ratio, lateral displacement, bending moment and shear force.

  3. Structure/property relationships in non-linear optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J M [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); [Durham Univ. (United Kingdom); Howard, J A.K. [Durham Univ. (United Kingdom); McIntyre, G J [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    The application of neutrons to the study of structure/property relationships in organic non-linear optical materials (NLOs) is described. In particular, charge-transfer effects and intermolecular interactions are investigated. Charge-transfer effects are studied by charge-density analysis and an example of one such investigation is given. The study of intermolecular interactions concentrates on the effects of hydrogen-bonding and an example is given of two structurally similar molecules with very disparate NLO properties, as a result of different types of hydrogen-bonding. (author). 3 refs.

  4. Composition-Structure-Property Relationships in Boroaluminosilicate Glasses

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Potuzak, M.; Mauro, J.C.

    2012-01-01

    boroaluminosilicate glasses from peralkaline to peraluminous compositions by substituting Al2O3 for SiO2. Our results reveal a pronounced change in all the measured physical properties (density, elastic moduli, hardness, glass transition temperature, and liquid fragility) around [Al2O3]–[Na2O]=0. The structural......The complicated structural speciation in boroaluminosilicate glasses leads to a mixed network former effect yielding nonlinear variation in many macroscopic properties as a function of chemical composition. Here we study the composition–structure–property relationships in a series of sodium...

  5. 3-alkyl fentanyl analogues: Structure-activity-relationship study

    OpenAIRE

    Vučković, Sonja; Savić-Vujović, Katarina; Srebro, Dragana; Ivanović, Milovan; Došen-Mićović, Ljiljana; Stojanović, Radan; Prostran, Milica

    2012-01-01

    Introduction. Fentanyl belongs to 4-anilidopiperidine class of synthetic opioid analgesics. It is characterized by high potency, rapid onset and short duration of action. A large number of fentanyl analogues have been synthesized so far, both to establish the structure-activity-relationship (SAR) and to find novel, clinically useful analgesic drugs. Objective. In this study, newly synthesized 3-alkyl fentanyl analogues were examined for analgesic activity and compared with fentanyl. Methods. ...

  6. Structure-activity relationship of crustacean peptide hormones.

    Science.gov (United States)

    Katayama, Hidekazu

    2016-01-01

    In crustaceans, various physiological events, such as molting, vitellogenesis, and sex differentiation, are regulated by peptide hormones. To understanding the functional sites of these hormones, many structure-activity relationship (SAR) studies have been published. In this review, the author focuses the SAR of crustacean hyperglycemic hormone-family peptides and androgenic gland hormone and describes the detailed results of our and other research groups. The future perspectives will be also discussed.

  7. [Eyeball structure changes in high myopic patients and their significance for forensic assessment].

    Science.gov (United States)

    Liu, Yi-Chang; Xia, Wen-Tao; Zhou, Xing-Tao; Liu, Rui-Jue; Bian, Shi-Zhong; Ying, Chong-Liang; Zhu, Guang-You

    2008-10-01

    There are irreversible eyeball structural changes in high myopic patients. These changes include axial length, corneal radius, anterior chamber depth, fundus degeneration, macula thickness, etc. There is a close relationship between the damage degree of visual function and these changes. The incidence of complications, such as vitreous opacity, posterior vitreous detachment, cataract, glaucoma, posterior staphyloma and retina detachment, is also highly related to the myopia diopter. More and more researches have indicated that the myopia diopter and the level of visual function are affected by multiple factors. It is promising to detect all of these changes by different kinds of methods, and to assess visual function through these changes. By clarifying these changes, it is also useful to distinguish traumatic damage from disease to provide evidence for forensic assessment of eye injuries.

  8. Structure-property relationships of multiferroic materials: A nano perspective

    Science.gov (United States)

    Bai, Feiming

    The integration of sensors, actuators, and control systems is an ongoing process in a wide range of applications covering automotive, medical, military, and consumer electronic markets. Four major families of ceramic and metallic actuators are under development: piezoelectrics, electrostrictors, magnetostrictors, and shape-memory alloys. All of these materials undergo at least two phase transformations with coupled thermodynamic order parameters. These transformations lead to complex domain wall behaviors, which are driven by electric fields (ferroelectrics), magnetic fields (ferromagnetics), or mechanical stress (ferroelastics) as they transform from nonferroic to ferroic states, contributing to the sensing and actuating capabilities. This research focuses on two multiferroic crystals, Pb(Mg1/3Nb 2/3)O3-PbTiO3 and Fe-Ga, which are characterized by the co-existence and coupling of ferroelectric polarization and ferroelastic strain, or ferro-magnetization and ferroelastic strain. These materials break the conventional boundary between piezoelectric and electrostrictors, or magnetostrictors and shape-memory alloys. Upon applying field or in a poled condition, they yield not only a large strain but also a large strain over field ratio, which is desired and much benefits for advanced actuator and sensor applications. In this thesis, particular attention has been given to understand the structure-property relationships of these two types of materials from atomic to the nano/macro scale. X-ray and neutron diffraction were used to obtain the lattice structure and phase transformation characteristics. Piezoresponse and magnetic force microscopy were performed to establish the dependence of domain configurations on composition, thermal history and applied fields. It has been found that polar nano regions (PNRs) make significant contributions to the enhanced electromechanical properties of PMN-x%PT crystals via assisting intermediate phase transformation. With increasing PT

  9. A structural nonparametric reappraisal of the CO2 emissions-income relationship

    NARCIS (Netherlands)

    Azomahou, T.T.; Goedhuys - Degelin, Micheline; Nguyen-Van, P.

    Relying on a structural nonparametric estimation, we show that co2 emissions clearly increase with income at low income levels. For higher income levels, we observe a decreasing relationship, though not significant. We also find thatco2 emissions monotonically increases with energy use at a

  10. Impact of functional and structural social relationships on two year depression outcomes: A multivariate analysis.

    Science.gov (United States)

    Davidson, Sandra K; Dowrick, Christopher F; Gunn, Jane M

    2016-03-15

    High rates of persistent depression highlight the need to identify the risk factors associated with poor depression outcomes and to provide targeted interventions to people at high risk. Although social relationships have been implicated in depression course, interventions targeting social relationships have been disappointing. Possibly, interventions have targeted the wrong elements of relationships. Alternatively, the statistical association between relationships and depression course is not causal, but due to shared variance with other factors. We investigated whether elements of social relationships predict major depressive episode (MDE) when multiple relevant variables are considered. Data is from a longitudinal study of primary care patients with depressive symptoms. 494 participants completed questionnaires at baseline and a depression measure (PHQ-9) two years later. Baseline measures included functional (i.e. quality) and structural (i.e. quantity) social relationships, depression, neuroticism, chronic illness, alcohol abuse, childhood abuse, partner violence and sociodemographic characteristics. Logistic regression with generalised estimating equations was used to estimate the association between social relationships and MDE. Both functional and structural social relationships predicted MDE in univariate analysis. Only functional social relationships remained significant in multivariate analysis (OR: 0.87; 95%CI: 0.79-0.97; p=0.01). Other unique predictors of MDE were baseline depression severity, neuroticism, childhood sexual abuse and intimate partner violence. We did not assess how a person's position in their depression trajectory influenced the association between social relationships and depression. Interventions targeting relationship quality may be part of a personalised treatment plan for people at high risk due of persistent depression due to poor social relationships. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Structure-activity relationship studies of the aromatic positions in cyclopentapeptide CXCR4 antagonists

    DEFF Research Database (Denmark)

    Mungalpara, Jignesh; Zachariassen, Zack G; Thiele, Stefanie

    2013-01-01

    , and autoimmune diseases. While the structure-activity relationships for Arg(1), Arg(2), and Gly(4) are well established, less is understood about the roles of the aromatic residues 2-Nal(3) and D-Tyr(5). Here we report further structure-activity relationship studies of these two positions, which showed that (i......) the distal aromatic ring of the 2-Nal(3) side chain is required in order to maintain high potency and (ii) replacement of D-Tyr(5) with conformationally constrained analogues results in significantly reduced activity. However, a simplified analogue that contained Gly instead of D-Tyr(5) was only 13-fold less...

  12. Brain structure and the relationship with neurocognitive functioning in schizophrenia and bipolar disorder : MRI studies

    OpenAIRE

    Hartberg, Cecilie Bhandari

    2011-01-01

    Brain structural abnormalities as well as neurocognitive dysfunction, are found in schizophrenia and in bipolar disorder. Based on the fact that both brain structure and neurocognitive functioning are significantly heritable and affected in both schizophrenia and bipolar disorder, relationships between them are expected. However, previous studies report inconsistent findings. Also, schizophrenia and bipolar disorder are classified as separate disease entities, but demonstrate overlap with reg...

  13. The Relationship between Racial Identity and Perceived Significance of the Election of President Barack Obama among African American Mothers.

    Science.gov (United States)

    Franco, Marisa; Smith-Bynum, Mia

    2016-01-01

    African American women's racial identity is a major determinant for how they interpret the world around them, yet there is little research examining how specific aspects of racial identity are linked with attitudes about an event that has been highly significant for African-Americans: the election of President Barack Obama. The current study examined the relationship between African American mothers' racial identity and their perceived significance of the election of President Barack Obama as an indicator of reduced systemic and actual racism for African Americans, using a sample of 110 African American mothers residing in a Northeastern metropolitan area. Results revealed that racial centrality and assimilation positively predicted perceived significance of President Obama's election for diminishing racism. Implications and future directions are discussed.

  14. Structure-rheology relationship in a sheared lamellar fluid.

    Science.gov (United States)

    Jaju, S J; Kumaran, V

    2016-03-01

    The structure-rheology relationship in the shear alignment of a lamellar fluid is studied using a mesoscale model which provides access to the lamellar configurations and the rheology. Based on the equations and free energy functional, the complete set of dimensionless groups that characterize the system are the Reynolds number (ργL(2)/μ), the Schmidt number (μ/ρD), the Ericksen number (μγ/B), the interface sharpness parameter r, the ratio of the viscosities of the hydrophilic and hydrophobic parts μ(r), and the ratio of the system size and layer spacing (L/λ). Here, ρ and μ are the fluid density and average viscosity, γ is the applied strain rate, D is the coefficient of diffusion, B is the compression modulus, μ(r) is the maximum difference in the viscosity of the hydrophilic and hydrophobic parts divided by the average viscosity, and L is the system size in the cross-stream direction. The lattice Boltzmann method is used to solve the concentration and momentum equations for a two dimensional system of moderate size (L/λ=32) and for a low Reynolds number, and the other parameters are systematically varied to examine the qualitative features of the structure and viscosity evolution in different regimes. At low Schmidt numbers where mass diffusion is faster than momentum diffusion, there is fast local formation of randomly aligned domains with "grain boundaries," which are rotated by the shear flow to align along the extensional axis as time increases. This configuration offers a high resistance to flow, and the layers do not align in the flow direction even after 1000 strain units, resulting in a viscosity higher than that for an aligned lamellar phase. At high Schmidt numbers where momentum diffusion is fast, the shear flow disrupts layers before they are fully formed by diffusion, and alignment takes place by the breakage and reformation of layers by shear, resulting in defects (edge dislocations) embedded in a background of nearly aligned layers

  15. Significance of fluid-structure interaction phenomena for containment response to ex-vessel steam explosions

    Energy Technology Data Exchange (ETDEWEB)

    Almstroem, H.; Sundel, T. [National Defence Research Establishment, Stockholm (Sweden); Frid, W.; Engelbrektson, A.

    1998-01-01

    When studying the structural response of a containment building to ex-vessel steam explosion loads, a two-step procedure is often used. In the first step of this procedure the structures are treated as rigid and the pressure-time history generated by the explosion at the rigid wall is calculated. In the second step the calculated pressure is applied to the structures. The obvious weakness of the two-step procedure is that it does not correspond to the real dynamic behaviour of the fluid-structure system. The purpose of this paper is to identify and evaluate the relevant fluid-structure interaction phenomena. This is achieved through direct treatment of the explosion process and the structural response. The predictions of a direct and two-step treatment are compared for a BWR Mark II containment design, consisting of two concentric walls interacting with water masses in the central and annular pools. It is shown that the two-step approach leads to unrealistic energy transfer in the containment system studied, and to significant overestimation of the deflection of the containment wall. As regards the pedestal wall, the direct method analysis shows that the flexibility of this wall affects the pressure-time history considerably. Three load types have been identified for this wall namely shock load, water blow as a result of water cavitation, and hydrodynamic load. Reloading impulse due to cavitation phenomena plays an important role as it amounts to about 40% of the total impulse load. Investigation of the generality of the cavitation phenomena in the context of ex-vessel steam explosion loads was outside the scope of this work. (author)

  16. Significance of fluid-structure interaction phenomena for containment response to ex-vessel steam explosions

    Energy Technology Data Exchange (ETDEWEB)

    Almstroem, H.; Sundel, T. (Nat. Defence Res. Establ., Tumba (Sweden)); Frid, W. (Swedish Nuclear Power Inspectorate, SE-10658, Stockholm (Sweden)); Engelbrektson, A. (VBB/SWECO, Box 34044, SE-10026, Stockholm (Sweden))

    1999-05-01

    When studying the structural response of a containment building to ex-vessel steam explosion loads, a two-step procedure is often used. In the first step of this procedure the structures are treated as rigid and the pressure-time history generated by the explosion, at the rigid wall, is calculated. In the second step the calculated pressure is applied to the structures. The obvious weakness of the two-step procedure is that it does not correspond to the real dynamic behaviour of the fluid-structure system. The purpose of this paper is to identify and evaluate the relevant fluid-structure interaction phenomena. This is achieved through direct treatment of the explosion process and the structural response. The predictions of a direct and two-step treatment are compared for a BWR Mark II containment design, consisting of two concentric walls interacting with water masses in the central and annular pools. It is shown that the two-step approach leads to unrealistic energy transfer in the containment system studied and to significant overestimation of the deflection of the containment wall. As regards the pedestal wall, the direct method analysis shows that the flexibility of this wall affects the pressure-time history considerably. Three load types have been identified for this wall namely shock load, water blow as a result of water cavitation, and hydrodynamic load. Reloading impulse due to cavitation phenomena plays an important role as it amounts to [approx]40% of the total impulse load. Investigation of the generality of the cavitation phenomena in the context of ex-vessel steam explosion loads was outside the scope of this work. (orig.) 5 refs.

  17. Significance of fluid-structure interaction phenomena for containment response to ex-vessel steam explosions

    International Nuclear Information System (INIS)

    Almstroem, H.; Sundel, T.; Frid, W.; Engelbrektson, A.

    1999-01-01

    When studying the structural response of a containment building to ex-vessel steam explosion loads, a two-step procedure is often used. In the first step of this procedure the structures are treated as rigid and the pressure-time history generated by the explosion, at the rigid wall, is calculated. In the second step the calculated pressure is applied to the structures. The obvious weakness of the two-step procedure is that it does not correspond to the real dynamic behaviour of the fluid-structure system. The purpose of this paper is to identify and evaluate the relevant fluid-structure interaction phenomena. This is achieved through direct treatment of the explosion process and the structural response. The predictions of a direct and two-step treatment are compared for a BWR Mark II containment design, consisting of two concentric walls interacting with water masses in the central and annular pools. It is shown that the two-step approach leads to unrealistic energy transfer in the containment system studied and to significant overestimation of the deflection of the containment wall. As regards the pedestal wall, the direct method analysis shows that the flexibility of this wall affects the pressure-time history considerably. Three load types have been identified for this wall namely shock load, water blow as a result of water cavitation, and hydrodynamic load. Reloading impulse due to cavitation phenomena plays an important role as it amounts to ∼40% of the total impulse load. Investigation of the generality of the cavitation phenomena in the context of ex-vessel steam explosion loads was outside the scope of this work. (orig.)

  18. Modeling process-structure-property relationships for additive manufacturing

    Science.gov (United States)

    Yan, Wentao; Lin, Stephen; Kafka, Orion L.; Yu, Cheng; Liu, Zeliang; Lian, Yanping; Wolff, Sarah; Cao, Jian; Wagner, Gregory J.; Liu, Wing Kam

    2018-02-01

    This paper presents our latest work on comprehensive modeling of process-structure-property relationships for additive manufacturing (AM) materials, including using data-mining techniques to close the cycle of design-predict-optimize. To illustrate the processstructure relationship, the multi-scale multi-physics process modeling starts from the micro-scale to establish a mechanistic heat source model, to the meso-scale models of individual powder particle evolution, and finally to the macro-scale model to simulate the fabrication process of a complex product. To link structure and properties, a highefficiency mechanistic model, self-consistent clustering analyses, is developed to capture a variety of material response. The model incorporates factors such as voids, phase composition, inclusions, and grain structures, which are the differentiating features of AM metals. Furthermore, we propose data-mining as an effective solution for novel rapid design and optimization, which is motivated by the numerous influencing factors in the AM process. We believe this paper will provide a roadmap to advance AM fundamental understanding and guide the monitoring and advanced diagnostics of AM processing.

  19. Ownership structures of principal petroleum companies in Canada: company profiles - significant events - takeovers and acquisitions

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    This reference document on ownership structures of principal petroleum companies identifies 'who owns whom' in the Canadian petroleum industry. The publication consists of three chapters. Chapter one, entitled 'Corporate Structures' includes the equity linkages between the energy enterprise and its parents and subsidiaries, names of directors and officers of the company and their ownership of voting shares. Chapter two under the title of 'Significant Events', provides company incorporation and listing data, outlining information on address of the company's head office, the nature of its business, number of employees in Canada, and stock exchanges on which the company equity is listed, stock symbol, high, low and closing prices as of December 31, 1996. Chapter three, entitled 'Takeovers and Acquisitions 1976-1997, provides a list of purchases, mergers and acquisitions and the estimated value of each, where applicable. All information included is provided by the companies themselves

  20. Structural design significance of tension-tension fatigue data on composites

    Science.gov (United States)

    Grimes, G. C.

    1977-01-01

    Constant cycle tension-tension fatigue and related static tension data have been generated on six single composite material/orientation combinations and twenty-one hybrid composite material/orientation combinations. Anomalies are related to the temperature rise and stopped interval creep, whereas endurance limit stresses (runouts) are associated with static proportional limit values, when they occur, and internal damage. The significance of these room temperature-dry data on the design allowables and weight of aerodynamic structueres is discussed. Such structures are helicopter rotor blades and wing and horizontal stabilizer lower surfaces. Typical criteria for turning these data into preliminary allowables are shown, as are examples of such allowables developed from the data. These values are then compared to those that might be used if the structures were made of metal.

  1. Significance of agricultural row structure on the microwave emissivity of soils

    Science.gov (United States)

    Promes, P. M.; Jackson, T. J.; O'Neill, P. E.

    1987-01-01

    A series of field experiments was carried out to extend the data base available for verifying agricultural row effect models of emissivity. The row effects model was used to simulate a data base from which an algorithm could be developed to account for row effects when the scene dielectric constant and small-scale roughness are unknown. One objective of the study was to quantify the significance of row structure and to develop a practical procedure for removing the effects of periodic row structure on the microwave emissivity of a soil in order to use the emissivity values to estimate the soil moisture. A second objective was to expand the data set available for model verification through field observations using a truck-mounted 1.4-GHz microwave radiometer.

  2. Phylogeographic analysis reveals significant spatial genetic structure of Incarvillea sinensis as a product of mountain building

    Directory of Open Access Journals (Sweden)

    Chen Shaotian

    2012-04-01

    Full Text Available Abstract Background Incarvillea sinensis is widely distributed from Southwest China to Northeast China and in the Russian Far East. The distribution of this species was thought to be influenced by the uplift of the Qinghai-Tibet Plateau and Quaternary glaciation. To reveal the imprints of geological events on the spatial genetic structure of Incarvillea sinensis, we examined two cpDNA segments ( trnH- psbA and trnS- trnfM in 705 individuals from 47 localities. Results A total of 16 haplotypes was identified, and significant genetic differentiation was revealed (GST =0.843, NST = 0.975, P  Conclusions The results revealed that the uplift of the Qinghai-Tibet Plateau likely resulted in the significant divergence between the lineage in the eastern Qinghai-Tibet Plateau and the other one outside this area. The diverse niches in the eastern Qinghai-Tibet Plateau created a wide spectrum of habitats to accumulate and accommodate new mutations. The features of genetic diversity of populations outside the eastern Qinghai-Tibet Plateau seemed to reveal the imprints of extinction during the Glacial and the interglacial and postglacial recolonization. Our study is a typical case of the significance of the uplift of the Qinghai-Tibet Plateau and the Quaternary Glacial in spatial genetic structure of eastern Asian plants, and sheds new light on the evolution of biodiversity in the Qinghai-Tibet Plateau at the intraspecies level.

  3. Statistical significance of theoretical predictions: A new dimension in nuclear structure theories (I)

    International Nuclear Information System (INIS)

    DUDEK, J; SZPAK, B; FORNAL, B; PORQUET, M-G

    2011-01-01

    In this and the follow-up article we briefly discuss what we believe represents one of the most serious problems in contemporary nuclear structure: the question of statistical significance of parametrizations of nuclear microscopic Hamiltonians and the implied predictive power of the underlying theories. In the present Part I, we introduce the main lines of reasoning of the so-called Inverse Problem Theory, an important sub-field in the contemporary Applied Mathematics, here illustrated on the example of the Nuclear Mean-Field Approach.

  4. Relationship and significance of serum leptin with blood insulin and lipid in 6-13 years old obese children

    International Nuclear Information System (INIS)

    Sheng Chunyong; Wang Chunlan; Zhang Linong

    2005-01-01

    To explore relationship and significance of Serum Leptin with BMI, Insulin, triglyceride (TG) and total cholesterol (TC) in obese children aged 6-13 years. Serum Leptin of school-age children 118 (64 male, 54 female; normal non-obese 56 and obese 62) were deter- mined and compared with BMI, Insulin, TG and TC. The results showed that: (1) Each index of obese children was remarkably higher than that of non-obese children (P 0.05). (3) Leptin was poritinely corelation with BMI, insulin, TG and TC(P=0.001). Leptin level in serum may varied according to sex, BMI or blood lipid level. It is of great significance in prevention and treatment of obesity to use drug which may improve Leptin receptor effect. (authors)

  5. Striving to be known by significant others: automatic activation of self-verification goals in relationship contexts.

    Science.gov (United States)

    Kraus, Michael W; Chen, Serena

    2009-07-01

    Extending research on the automatic activation of goals associated with significant others, the authors hypothesized that self-verification goals typically pursued with significant others are automatically elicited when a significant-other representation is activated. Supporting this hypothesis, the activation of a significant-other representation through priming (Experiments 1 and 3) or through a transference encounter (Experiment 2) led participants to seek feedback that verifies their preexisting self-views. Specifically, significant-other primed participants desired self-verifying feedback, in general (Experiment 1), from an upcoming interaction partner (Experiment 2), and relative to acquaintance-primed participants and favorable feedback (Experiment 3). Finally, self-verification goals were activated, especially for relational self-views deemed high in importance to participants' self-concepts (Experiment 2) and held with high certainty (Experiment 3). Implications for research on self-evaluative goals, the relational self, and the automatic goal activation literature are discussed, as are consequences for close relationships. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

  6. Adolescent Executive Dysfunction in Daily Life: Relationships to Risks, Brain Structure and Substance Use

    Directory of Open Access Journals (Sweden)

    Duncan B. Clark

    2017-11-01

    Full Text Available During adolescence, problems reflecting cognitive, behavioral and affective dysregulation, such as inattention and emotional dyscontrol, have been observed to be associated with substance use disorder (SUD risks and outcomes. Prior studies have typically been with small samples, and have typically not included comprehensive measurement of executive dysfunction domains. The relationships of executive dysfunction in daily life with performance based testing of cognitive skills and structural brain characteristics, thought to be the basis for executive functioning, have not been definitively determined. The aims of this study were to determine the relationships between executive dysfunction in daily life, measured by the Behavior Rating Inventory of Executive Function (BRIEF, cognitive skills and structural brain characteristics, and SUD risks, including a global SUD risk indicator, sleep quality, and risky alcohol and cannabis use. In addition to bivariate relationships, multivariate models were tested. The subjects (n = 817; ages 12 through 21 were participants in the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA study. The results indicated that executive dysfunction was significantly related to SUD risks, poor sleep quality, risky alcohol use and cannabis use, and was not significantly related to cognitive skills or structural brain characteristics. In multivariate models, the relationship between poor sleep quality and risky substance use was mediated by executive dysfunction. While these cross-sectional relationships need to be further examined in longitudinal analyses, the results suggest that poor sleep quality and executive dysfunction may be viable preventive intervention targets to reduce adolescent substance use.

  7. Structure-Property Relationship in High Tg Thermosetting Polyimides

    Science.gov (United States)

    Chuang, Kathy C.; Meador, Mary Ann B.; HardyGreen, DeNise

    2000-01-01

    This viewgraph presentation gives an overview of the structure-property relationship in high glass transition temperatures (T(sub g)) thermosetting polyimides. The objectives of this work are to replace MDA in PMR-15 with 2,2-substituted benzidine and to evaluate the thermo-oxidative stability and mechanical properties of DMBZ-15 against PMR-15. Details are given on the T(sub g) of polyimide resins, the x-ray crystal structure of 2,2-Bis(trifluoro)benzidine (BFBZ), the isothermal aging of polyimide resins at 288 C under 1 atm of circulating air, the compressive strength of polyimide composites, and a gas evaluation profile of DMBZ-15 polyimide resins.

  8. Structure/property relationships in multipass GMA welding of beryllium.

    Energy Technology Data Exchange (ETDEWEB)

    Hochanadel, P. W. (Patrick W.); Hults, W. L. (William L.); Thoma, D. J. (Dan J.); Dave, V. R. (Vivek R.); Kelly, A. M. (Anna Marie); Pappin, P. A. (Pallas A.); Cola, M. J. (Mark J.); Burgardt, P. (Paul)

    2001-01-01

    Beryllium is an interesting metal that has a strength to weight ratio six times that of steel. Because of its unique mechanical properties, beryllium is used in aerospace applications such as satellites. In addition, beryllium is also used in x-ray windows because it is nearly transparent to x-rays. Joining of beryllium has been studied for decades (Ref.l). Typically joining processes include braze-welding (either with gas tungsten arc or gas metal arc), soldering, brazing, and electron beam welding. Cracking which resulted from electron beam welding was recently studied to provide structure/property relationships in autogenous welds (Ref. 2). Braze-welding utilizes a welding arc to melt filler, and only a small amount of base metal is melted and incorporated into the weld pool. Very little has been done to characterize the braze-weld in terms of the structure/property relationships, especially with reference to multipass welding. Thus, this investigation was undertaken to evaluate the effects of multiple passes on microstructure, weld metal composition, and resulting material properties for beryllium welded with aluminum-silicon filler metal.

  9. The relationship between cerebral infarction on MR and angiographic findings in moyamoya disease: significance of the posterior circulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ja; Song, Soon Young [College of Medicine, Kwangdong Univ., Koyang (Korea, Republic of); Yu, Won Jong; Jung, So Lyung; Chung, Bong Gak; Kag, Si Won [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Man Deuk [College of Medicine, Pochon CHA Univ., Pochon (Korea, Republic of)

    2002-06-01

    To investigate the relationship between changes in the posterior and anterior circulation, as seen at angiography, and the frequency and extent of cerebral infarction revealed by MR imaging in moyamoya disease. This study involved 34 patients (22 females and 12 males, aged 2-52 years) in whom cerebral angiography revealed the presence of moyamoya disease (bilateral; unilateral= 24:10; total hemispheres=58) and who also underwent brain MR imaging. To evaluate the angiographic findings, we applied each angiographic staging system to the anterior and posterior circulation. Leptomeningeal collateral circulation from the cortical branches of the posterior cerebral artery (PCA) was also assigned one of four grades. At MR imaging, areas of cerebral cortical or subcortical infarction in the hemisphere were divided into six zones. White matter and basal ganglionic infarction, ventricular dilatation, cortical atrophy, and hemorrhagic lesions were also evaluated. To demonstrate the statistical significance of the relationship between the angiographic and the MR findings, both the Mantel-Haenszel chi-square test for trend and the chi-square test were used. The degree of steno-occlusive PCA change correlated significantly with the internal carotid artery (ICA) stage (p<0.0001). As PCA stages advanced, the degree of leptomeningeal collaterals from the PCA decreased significantly (P<0.0001), but ICA stages were not significant (p>0.05). The prevalence of infarction showed significant correlation with the degree of steno-occlusive change in both the ICA and PCA. The degree of cerebral ischemia in moyamoya patients increased proportionally with the severity of PCA stenosis rather than with that of steno-occlusive lesins of the anterior circulation. Infarctions tended to be distributed in the anterior part of the hemisphere at PCA state I or II, while in more advanced PCA lesions, they were also found posteriorly, especially in the territories of the posterior middle cerebral artery

  10. Improving the precision of the structure-function relationship by considering phylogenetic context.

    Directory of Open Access Journals (Sweden)

    2005-06-01

    Full Text Available Understanding the relationship between protein structure and function is one of the foremost challenges in post-genomic biology. Higher conservation of structure could, in principle, allow researchers to extend current limitations of annotation. However, despite significant research in the area, a precise and quantitative relationship between biochemical function and protein structure has been elusive. Attempts to draw an unambiguous link have often been complicated by pleiotropy, variable transcriptional control, and adaptations to genomic context, all of which adversely affect simple definitions of function. In this paper, I report that integrating genomic information can be used to clarify the link between protein structure and function. First, I present a novel measure of functional proximity between protein structures (F-score. Then, using F-score and other entirely automatic methods measuring structure and phylogenetic similarity, I present a three-dimensional landscape describing their inter-relationship. The result is a "well-shaped" landscape that demonstrates the added value of considering genomic context in inferring function from structural homology. A generalization of methodology presented in this paper can be used to improve the precision of annotation of genes in current and newly sequenced genomes.

  11. Statistically significant dependence of the Xaa-Pro peptide bond conformation on secondary structure and amino acid sequence

    Directory of Open Access Journals (Sweden)

    Leitner Dietmar

    2005-04-01

    Full Text Available Abstract Background A reliable prediction of the Xaa-Pro peptide bond conformation would be a useful tool for many protein structure calculation methods. We have analyzed the Protein Data Bank and show that the combined use of sequential and structural information has a predictive value for the assessment of the cis versus trans peptide bond conformation of Xaa-Pro within proteins. For the analysis of the data sets different statistical methods such as the calculation of the Chou-Fasman parameters and occurrence matrices were used. Furthermore we analyzed the relationship between the relative solvent accessibility and the relative occurrence of prolines in the cis and in the trans conformation. Results One of the main results of the statistical investigations is the ranking of the secondary structure and sequence information with respect to the prediction of the Xaa-Pro peptide bond conformation. We observed a significant impact of secondary structure information on the occurrence of the Xaa-Pro peptide bond conformation, while the sequence information of amino acids neighboring proline is of little predictive value for the conformation of this bond. Conclusion In this work, we present an extensive analysis of the occurrence of the cis and trans proline conformation in proteins. Based on the data set, we derived patterns and rules for a possible prediction of the proline conformation. Upon adoption of the Chou-Fasman parameters, we are able to derive statistically relevant correlations between the secondary structure of amino acid fragments and the Xaa-Pro peptide bond conformation.

  12. Independent component analysis reveals new and biologically significant structures in micro array data

    Directory of Open Access Journals (Sweden)

    Veerla Srinivas

    2006-06-01

    Full Text Available Abstract Background An alternative to standard approaches to uncover biologically meaningful structures in micro array data is to treat the data as a blind source separation (BSS problem. BSS attempts to separate a mixture of signals into their different sources and refers to the problem of recovering signals from several observed linear mixtures. In the context of micro array data, "sources" may correspond to specific cellular responses or to co-regulated genes. Results We applied independent component analysis (ICA to three different microarray data sets; two tumor data sets and one time series experiment. To obtain reliable components we used iterated ICA to estimate component centrotypes. We found that many of the low ranking components indeed may show a strong biological coherence and hence be of biological significance. Generally ICA achieved a higher resolution when compared with results based on correlated expression and a larger number of gene clusters with significantly enriched for gene ontology (GO categories. In addition, components characteristic for molecular subtypes and for tumors with specific chromosomal translocations were identified. ICA also identified more than one gene clusters significant for the same GO categories and hence disclosed a higher level of biological heterogeneity, even within coherent groups of genes. Conclusion Although the ICA approach primarily detects hidden variables, these surfaced as highly correlated genes in time series data and in one instance in the tumor data. This further strengthens the biological relevance of latent variables detected by ICA.

  13. The Relationship of Clinical Nurses' Perceptions of Structural and Psychological Empowerment and Engagement on Their Unit.

    Science.gov (United States)

    DiNapoli, Jean Marie; O'Flaherty, Deirdre; Musil, Carol; Clavelle, Joanne T; Fitzpatrick, Joyce J

    2016-02-01

    The purpose of this study was to describe relationships between structural empowerment, psychological empowerment, and engagement among clinical nurses. Empowerment and engagement are key drivers of retention and quality in healthcare. Creating an empowering culture and an engaged staff supports initiatives that are essential for positive work environments. A survey of 280 nurses in a national conference was conducted using the Conditions of Work Effectiveness, Psychological Empowerment Instrument, and the Utrecht Work Engagement Scale. Pearson correlation coefficients and multiple regression analysis were used to determine relationships between demographic data and study variables. Overall, nurses had high perceptions of structural empowerment and psychological empowerment and were moderately engaged. Also, significant positive relationships were found between the key study variables. Results show positive correlations between empowerment and perceived engagement among clinical nurses.

  14. Relationship Structure, Relationship Texture: Case Studies in Non/Monogamies Research

    Directory of Open Access Journals (Sweden)

    Jessica Joan Kean

    2017-05-01

    Full Text Available This article develops case studies from qualitative interviews with people in negotiated non-monogamous relationships to ask what discursive or practical factors besides non/monogamy might play a role in assessments of a relationship’s structure or worth. Beginning with an auto-ethnographic reflection on the way the ‘significance’ was recognised and misrecognised in one polyamorous ‘thrupple’, I introduce three case studies of people in negotiated non-monogamous relationships in order to bring a cultural studies method of the particular to the study of intimacy. For the individuals in these case studies, the practice and experience of non/monogamy is inextricably linked to the ideas and practices surrounding gender, sexuality, sex work, friendship, HIV status and ability. Sketching a middle path between the romantic’s dream of love as a state of exception or exemption from the social and the theorist’s map of the patterned effects of hetero- and mono-normativities, this article attends to the contingency, flexibility and incoherence which so often underpins the sense we make of relationships, even as that sense is shaped by the practices, ideals and institutions of intimacy, love and friendship.

  15. Changing structure of income indoor air pollution relationship in India

    International Nuclear Information System (INIS)

    Kavi Kumar, K.S.; Viswanathan, Brinda

    2007-01-01

    Bio fuels are still a major source for cooking by many households in developing countries such as India causing significant disease burden due to indoor air pollution. While household income influences the choice of fuel the policies that affect accessibility and price of fuels also have an important role in determining the fuel choice. This study analyzes the pollution-income relationship for the period 1983-2000, separately across rural and urban households in India based on unit record data on fuel consumption obtained through National Sample Surveys. While a non-monotonic relationship is observed in rural India in both the decades, in urban India a similar relationship is observed only for the initial period indicating faster transition towards 'cleaner' fuels mainly enabled by policies that have been pro-urban. The study also finds that the impact of household size and composition on bio fuels is more negative than for clean fuels and is increasingly negative over time possibly due to greater awareness about the ill effects of such fuels

  16. The structure and economic significance of government guarantees in Croatia and the European Union

    Directory of Open Access Journals (Sweden)

    Marko Primorac

    2016-03-01

    Full Text Available In the aftermath of the financial crisis, when countries are facing difficulties in raising the amounts of revenue needed to cover the expenditure side of the budget, fiscal risks can pose a significant threat to the sustainability of public finance. This became particularly evident in the case of public enterprises and their liabilities, which often increased public debt because of difficulties in meeting their financial obligations. The aim of this paper is to evaluate fiscal risks from government guarantees in Croatia and the European Union in general. Moreover, the paper aims to analyse the dynamics of the value and structure of government guarantees in Croatia in the period from 2009 to first half of 2015. Particular emphasis is placed on the impact of government guarantees on direct public debt in the context of methodological changes in the registration of public debt.

  17. Structure and design on menus in hospitality in Serbia as a significant sales tool in tourism

    Directory of Open Access Journals (Sweden)

    Kalenjuk Bojana

    2016-01-01

    Full Text Available Written offers represent the image of the operations of each hospitality facility, including a la carte menus that have the most important role. Proper structuring, number of meals, information about food and design, to a large extent, influence the choice of guests - tourists and their satisfaction. The implementation of appropriate scientific methodologies comprehend that the following parameters are important for the proper structuring and design of menus and the actual sale of foods, namely: guidance items and balance, diversity and composition of the offer, a description of the truth about food and information, the size and design of cover and paper, printing and color. The survey was conducted by direct and indirect collection of menus from a corresponding number of a la carte restaurants. The obtained data were subjected to analysis and synthesis, statistically processed and graphically presented in the paper. The results represent a picture of the situation in the hospitality industry in the Republic of Serbia, in terms of significant sales resources in tourism.

  18. Significance of Alkali-Silica reaction in nuclear safety-related concrete structures

    International Nuclear Information System (INIS)

    Le Pape, Y.; Field, K.G.; Mattus, C.H.; Naus, D.J.; Busby, J.T.; Saouma, V.; Ma, Z.J.; Cabage, J.V.; Guimaraes, M.

    2015-01-01

    Nuclear Power Plant license renewal up to 60 years and possible life extension beyond has established a renewed focus on long-term aging of nuclear generating stations materials, and particularly, on concrete. Large irreplaceable sections of most nuclear generating stations include concrete components. The Expanded Materials Degradation Analysis, jointly performed by the Department of Energy, the U.S. Nuclear Regulatory Commission, the Academia and the Power Generation Industry, identified the need to develop a consistent knowledge base of alkali-silica reaction (ASR) within concrete as an urgent priority (Graves et al., 2014). ASR results in an expansion of Concrete produced by the reaction between alkali (generally from cement), reactive aggregate (like amorphous silica) and water absorption. ASR causes expansion, cracking and loss of mechanical properties. Considering that US commercial reactors in operation enter the age when ASR distress can be potentially observed and that numerous non-nuclear infrastructures (transportation, energy production) in a majority of the States have already experienced ASR-related concrete degradation, the susceptibility and significance of ASR for nuclear concrete structures must be addressed. This paper outlines an on-going research program including the investigation of the possibility of ASR in nuclear power plants, and the assessment of the residual shear bearing capacity of ASR-subjected nuclear structures. (authors)

  19. Chemical and Biological Significance of Oenothein B and Related Ellagitannin Oligomers with Macrocyclic Structure

    Directory of Open Access Journals (Sweden)

    Takashi Yoshida

    2018-03-01

    Full Text Available In 1990, Okuda et al. reported the first isolation and characterization of oenothein B, a unique ellagitannin dimer with a macrocyclic structure, from the Oenothera erythrosepala leaves. Since then, a variety of macrocyclic analogs, including trimeric–heptameric oligomers have been isolated from various medicinal plants belonging to Onagraceae, Lythraceae, and Myrtaceae. Among notable in vitro and in vivo biological activities reported for oenothein B are antioxidant, anti-inflammatory, enzyme inhibitory, antitumor, antimicrobial, and immunomodulatory activities. Oenothein B and related oligomers, and/or plant extracts containing them have thus attracted increasing interest as promising targets for the development of chemopreventive agents of life-related diseases associated with oxygen stress in human health. In order to better understand the significance of this type of ellagitannin in medicinal plants, this review summarizes (1 the structural characteristics of oenothein B and related dimers; (2 the oxidative metabolites of oenothein B up to heptameric oligomers; (3 the distribution of oenotheins and other macrocyclic analogs in the plant kingdom; and (4 the pharmacological activities hitherto documented for oenothein B, including those recently found by our laboratory.

  20. Structure-Property Relationships in Amorphous Transparent Conducting Oxides

    Science.gov (United States)

    Moffitt, Stephanie Lucille

    Over the last 20 years a new field of amorphous transparent conducting oxides (a-TCOs) has developed. The amorphous nature of these films makes them well suited for large area applications. In addition, a-TCOs can be made at low temperatures and through solution processing methods. These assets provide promising opportunities to improve applications such as solar cells and back-lit displays where traditional crystalline TCOs are used. In addition, it opens the door for new technological applications including the possibility for transparent, flexible electronics. Despite the recent growth in this field, fundamental understanding of the true nature of conductivity and the amorphous structure in this materials system is still progressing. To develop a greater understanding of a-TCOs, structure-property relationships were developed in the a-IGO and a-IZO systems. From the combination of element-specific local structure studies and liquid quench molecular dynamics simulations it is clear that a degree of structure remains in a-TCOs. By understanding this structure, the effect of gallium on thermal stability, carrier concentration and carrier mobility is understood. The source of charge carriers in a-IZO is identified as oxygen vacancies through the application of in situ Brouwer analysis. The continued development of the Brouwer analysis technique for use in amorphous oxides adds to the available methods for studying defects in amorphous systems. Finally, the foundational knowledge gained from the in-depth study of a-IGO was extended to understand the role of combustion processing and pulsed laser deposition as growth methods for transistors based on a-IGO.

  1. Structure-Energy Relationships of Halogen Bonds in Proteins.

    Science.gov (United States)

    Scholfield, Matthew R; Ford, Melissa Coates; Carlsson, Anna-Carin C; Butta, Hawera; Mehl, Ryan A; Ho, P Shing

    2017-06-06

    The structures and stabilities of proteins are defined by a series of weak noncovalent electrostatic, van der Waals, and hydrogen bond (HB) interactions. In this study, we have designed and engineered halogen bonds (XBs) site-specifically to study their structure-energy relationship in a model protein, T4 lysozyme. The evidence for XBs is the displacement of the aromatic side chain toward an oxygen acceptor, at distances that are equal to or less than the sums of their respective van der Waals radii, when the hydroxyl substituent of the wild-type tyrosine is replaced by a halogen. In addition, thermal melting studies show that the iodine XB rescues the stabilization energy from an otherwise destabilizing substitution (at an equivalent noninteracting site), indicating that the interaction is also present in solution. Quantum chemical calculations show that the XB complements an HB at this site and that solvent structure must also be considered in trying to design molecular interactions such as XBs into biological systems. A bromine substitution also shows displacement of the side chain, but the distances and geometries do not indicate formation of an XB. Thus, we have dissected the contributions from various noncovalent interactions of halogens introduced into proteins, to drive the application of XBs, particularly in biomolecular design.

  2. Redox properties of structural Fe in clay minerals: 3. Relationships between smectite redox and structural properties.

    Science.gov (United States)

    Gorski, Christopher A; Klüpfel, Laura E; Voegelin, Andreas; Sander, Michael; Hofstetter, Thomas B

    2013-01-01

    Structural Fe in clay minerals is an important redox-active species in many pristine and contaminated environments as well as in engineered systems. Understanding the extent and kinetics of redox reactions involving Fe-bearing clay minerals has been challenging due to the inability to relate structural Fe(2+)/Fe(total) fractions to fundamental redox properties, such as reduction potentials (EH). Here, we overcame this challenge by using mediated electrochemical reduction (MER) and oxidation (MEO) to characterize the fraction of redox-active structural Fe (Fe(2+)/Fe(total)) in smectites over a wide range of applied EH-values (-0.6 V to +0.6 V). We examined Fe(2+)/Fe(total )- EH relationships of four natural Fe-bearing smectites (SWy-2, SWa-1, NAu-1, NAu-2) in their native, reduced, and reoxidized states and compared our measurements with spectroscopic observations and a suite of mineralogical properties. All smectites exhibited unique Fe(2+)/Fe(total) - EH relationships, were redox active over wide EH ranges, and underwent irreversible electron transfer induced structural changes that were observable with X-ray absorption spectroscopy. Variations among the smectite Fe(2+)/Fe(total) - EH relationships correlated well with both bulk and molecular-scale properties, including Fe(total) content, layer charge, and quadrupole splitting values, suggesting that multiple structural parameters determined the redox properties of smectites. The Fe(2+)/Fe(total) - EH relationships developed for these four commonly studied clay minerals may be applied to future studies interested in relating the extent of structural Fe reduction or oxidation to EH-values.

  3. The NMR structure of human obestatin in membrane-like environments: insights into the structure-bioactivity relationship of obestatin.

    Science.gov (United States)

    Alén, Begoña O; Nieto, Lidia; Gurriarán-Rodríguez, Uxía; Mosteiro, Carlos S; Álvarez-Pérez, Juan C; Otero-Alén, María; Camiña, Jesús P; Gallego, Rosalía; García-Caballero, Tomás; Martín-Pastor, Manuel; Casanueva, Felipe F; Jiménez-Barbero, Jesús; Pazos, Yolanda

    2012-01-01

    The quest for therapeutic applications of obestatin involves, as a first step, the determination of its 3D solution structure and the relationship between this structure and the biological activity of obestatin. On this basis, we have employed a combination of circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy, and modeling techniques to determine the solution structure of human obestatin (1). Other analogues, including human non-amidated obestatin (2) and the fragment peptides (6-23)-obestatin (3), (11-23)-obestatin (4), and (16-23)-obestatin (5) have also been scrutinized. These studies have been performed in a micellar environment to mimic the cell membrane (sodium dodecyl sulfate, SDS). Furthermore, structural-activity relationship studies have been performed by assessing the in vitro proliferative capabilities of these peptides in the human retinal pigmented epithelial cell line ARPE-19 (ERK1/2 and Akt phosphorylation, Ki67 expression, and cellular proliferation). Our findings emphasize the importance of both the primary structure (composition and size) and particular segments of the obestatin molecule that posses significant α-helical characteristics. Additionally, details of a species-specific role for obestatin have also been hypothesized by comparing human and mouse obestatins (1 and 6, respectively) at both the structural and bioactivity levels.

  4. The NMR structure of human obestatin in membrane-like environments: insights into the structure-bioactivity relationship of obestatin.

    Directory of Open Access Journals (Sweden)

    Begoña O Alén

    Full Text Available The quest for therapeutic applications of obestatin involves, as a first step, the determination of its 3D solution structure and the relationship between this structure and the biological activity of obestatin. On this basis, we have employed a combination of circular dichroism (CD, nuclear magnetic resonance (NMR spectroscopy, and modeling techniques to determine the solution structure of human obestatin (1. Other analogues, including human non-amidated obestatin (2 and the fragment peptides (6-23-obestatin (3, (11-23-obestatin (4, and (16-23-obestatin (5 have also been scrutinized. These studies have been performed in a micellar environment to mimic the cell membrane (sodium dodecyl sulfate, SDS. Furthermore, structural-activity relationship studies have been performed by assessing the in vitro proliferative capabilities of these peptides in the human retinal pigmented epithelial cell line ARPE-19 (ERK1/2 and Akt phosphorylation, Ki67 expression, and cellular proliferation. Our findings emphasize the importance of both the primary structure (composition and size and particular segments of the obestatin molecule that posses significant α-helical characteristics. Additionally, details of a species-specific role for obestatin have also been hypothesized by comparing human and mouse obestatins (1 and 6, respectively at both the structural and bioactivity levels.

  5. Atomic-level structure and structure-property relationship in metallic glass

    Science.gov (United States)

    Cheng, Yongqiang

    One of the key tasks in material science is to understand the structure and structure-property relationship. The recently emerging bulk metallic glasses (BMGs) have demonstrated unique properties, especially intriguing mechanical properties such as their high strength and high propensity to localize deformation in shear bands. However, a comprehensive understanding of the structure of BMGs has been hindered by the complexity of these amorphous materials. Even more challenging is the structure-property correlation, which has been well established in crystals but has been seriously lacking for BMGs. This thesis presents a systematic study of the atomic-level structures of two representative BMGs, Cu-Zr and Cu-Zr-Al. The interpenetrating Cu-centered icosahedral clusters have been identified to be the primary structural feature. The fraction of icosahedra increases with increasing Cu or Al contents, and with decreasing cooling rate. The effect of Al in improving the icosahedral order is two-fold: the geometric effect due to the atomic-size mismatch and the chemical effect originated from the Cu-Al bond shortening. The resolved structure is used to study the structure-property relationship. The full icosahedra are found to be responsible for the dynamical slowdown of the supercooled liquid, which underlies the non-Arrhenius behavior, and explains the composition dependence of glass transition temperature, glass forming ability, and the room temperature strength. By simulated deformation, the initiation of plasticity and tendency for strain localization are also investigated. The full icosahedra are found to be the most rigid and resistant cluster with solid-like character, while the unstable clusters with liquid-like character serve as the fertile sites for initiating shear transformations. In addition, the elastic moduli are calculated and analyzed, and the origins of the different configurational dependence of shear modulus (G) and bulk modulus ( B) are explained. The

  6. Polylactide based nanocomposites: Processing, structure and performance relationship

    Science.gov (United States)

    Karami, Shahir

    The application of biodegradable polymers has been offered to the packing industry wishing to overcome the environmental consequence of employing the petroleum-based polymers. Furthermore, the unstable oil market urged the industry to look for the substitution of the renewable resources. Polylactide is known as the most popular biodegradable polymer developed on a large scale. Nevertheless, the growing contribution of polylactide to packing industry is somewhat restricted owing to its inherent brittleness and weak barrier properties. Therefore, the main objective of this thesis was defined to build a fundamental relationship between processing parameters and solid-state microstructure to improve the performance of polylactide. Polylactide nanocomposites were prepared through a multi-step melt compounding process. Dispersion of organically modified layered nanoparticles was detected by the WAXS and TEM characterizations, demonstrating the formation of intercalated nanocomposites. Relaxation spectrum exhibited the restricted dynamics of fraction of amorphous phase confined in polymer-particle interphase through dynamic rheological measurements. The fraction of rigid amorphous chains was estimated using TMDSC and DMA. This increased with nanoparticle content, levelling off upon the aggregation of nanoparticles. The annealing-induced molecular ordering was detected by FR-IR, increasing the rigid amorphous fraction. Cold crystallization was investigated during non-isothermal process using TMDSC. Crystallization kinetic was studied through the evaluation of Avrami parameters in isothermal process at the temperature range of Tg+30°C to Tg+70°C. The crystallization rate depressed with the nanoparticle content due to the enhanced fraction of rigid amorphous chains, as well as, the topological constraints derived from the formation of network structure. Nevertheless, the nanoparticles acted as heterogeneous nucleating sites upon devitrification of the rigid amorphous

  7. Chemistry and Structure-Activity Relationships of Psychedelics.

    Science.gov (United States)

    Nichols, David E

    2018-01-01

    This chapter will summarize structure-activity relationships (SAR) that are known for the classic serotonergic hallucinogens (aka psychedelics), focusing on the three chemical types: tryptamines, ergolines, and phenethylamines. In the brain, the serotonin 5-HT 2A receptor plays a key role in regulation of cortical function and cognition, and also appears to be the principal target for hallucinogenic/psychedelic drugs such as LSD. It is one of the most extensively studied of the 14 known types of serotonin receptors. Important structural features will be identified for activity and, where possible, those that the psychedelics have in common will be discussed. Because activation of the 5-HT 2A receptor is the principal mechanism of action for psychedelics, compounds with 5-HT 2A agonist activity generally are quickly discarded by the pharmaceutical industry. Thus, most of the research on psychedelics can be related to activation of 5-HT 2A receptors. Therefore, much of the discussion will include not only clinical or anecdotal studies, but also will consider data from animal models as well as a certain amount of molecular pharmacology where it is known.

  8. Quantitative structure-cytotoxicity relationship of piperic acid amides.

    Science.gov (United States)

    Shimada, Chiyako; Uesawa, Yoshihiro; Ishihara, Mariko; Kagaya, Hajime; Kanamoto, Taisei; Terakubo, Shigemi; Nakashima, Hideki; Takao, Koichi; Miyashiro, Takaki; Sugita, Yoshiaki; Sakagami, Hiroshi

    2014-09-01

    A total of 12 piperic acid amides, including piperine, were subjected to quantitative structure-activity relationship (QSAR) analysis, based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to find new biological activities. Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and three human oral normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor selectivity was evaluated by the ratio of the mean 50% cytotoxic concentration (CC50) against normal oral cells to that against OSCC cell lines. Anti-HIV activity was evaluated by the ratio of the CC50 to 50% HIV infection-cytoprotective concentration (EC50). Physicochemical, structural, and quantum-chemical parameters were calculated based on the conformations optimized by LowModeMD method followed by density functional theory method. All compounds showed low-to-moderate tumor selectivity, but no anti-HIV activity. N-Piperoyldopamine ( 8: ) which has a catechol moiety, showed the highest tumor selectivity, possibly due to its unique molecular shape and electrostatic interaction, especially its largest partial equalization of orbital electronegativities and vsurf descriptors. The present study suggests that molecular shape and ability for electrostatic interaction are useful parameters for estimating the tumor selectivity of piperic acid amides. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  9. Testing statistical significance scores of sequence comparison methods with structure similarity

    Directory of Open Access Journals (Sweden)

    Leunissen Jack AM

    2006-10-01

    Full Text Available Abstract Background In the past years the Smith-Waterman sequence comparison algorithm has gained popularity due to improved implementations and rapidly increasing computing power. However, the quality and sensitivity of a database search is not only determined by the algorithm but also by the statistical significance testing for an alignment. The e-value is the most commonly used statistical validation method for sequence database searching. The CluSTr database and the Protein World database have been created using an alternative statistical significance test: a Z-score based on Monte-Carlo statistics. Several papers have described the superiority of the Z-score as compared to the e-value, using simulated data. We were interested if this could be validated when applied to existing, evolutionary related protein sequences. Results All experiments are performed on the ASTRAL SCOP database. The Smith-Waterman sequence comparison algorithm with both e-value and Z-score statistics is evaluated, using ROC, CVE and AP measures. The BLAST and FASTA algorithms are used as reference. We find that two out of three Smith-Waterman implementations with e-value are better at predicting structural similarities between proteins than the Smith-Waterman implementation with Z-score. SSEARCH especially has very high scores. Conclusion The compute intensive Z-score does not have a clear advantage over the e-value. The Smith-Waterman implementations give generally better results than their heuristic counterparts. We recommend using the SSEARCH algorithm combined with e-values for pairwise sequence comparisons.

  10. Meniscofibular Ligament: Morphology and Functional Significance of a Relatively Unknown Anatomical Structure

    Directory of Open Access Journals (Sweden)

    K. Natsis

    2012-01-01

    Full Text Available Purpose. A relatively unknown ligamentous structure of the posterolateral corner of the knee joint, the so-called meniscofibular ligament (MFL, was investigated as regards its macroscopic morphology, its histological features, and its reaction to knee movements. Material and Methods. MFL was exposed on 21 fresh-frozen unpaired knee joints. Its microscopic morphology was examined utilizing for comparison the fibular collateral and the popliteofibular ligament. Results. MFL was encountered in 100% of the specimens as a thin striplike fibrous band extending between the lower border of the lateral meniscus and the head of the fibula. MFL was tense during knee extension and external rotation of the tibia, whereas its histological features were similar to those of fibular collateral and popliteofibular ligament. Discussion. Its precise histological nature is studied as well as its tension alterations during knee movements. The potential functional significance of the MFL with respect to its role in avoidance of lateral meniscus and lateral coronary ligament tears is discussed. Conclusions. MFL presumably provides an additional protection to the lateral meniscus during the last stages of knee extension, as well as to the lateral coronary ligament reducing the possibility of a potential rupture.

  11. Critical zone structure controls concentration-discharge relationships and solute generation in forested tropical montane watersheds

    Science.gov (United States)

    Wymore, Adam S.; Brereton, Richard L.; Ibarra, Daniel E.; Maher, Kate; McDowell, William H.

    2017-07-01

    Concentration-discharge (C-Q) relationships are poorly known for tropical watersheds, even though the tropics contribute a disproportionate amount of solutes to the global ocean. The Luquillo Mountains in Puerto Rico offer an ideal environment to examine C-Q relationships across a heterogeneous tropical landscape. We use 10-30 years of weekly stream chemistry data across 10 watersheds to examine C-Q relationships for weathering products (SiO2(aq), Ca2+, Mg2+, and Na+) and biologically controlled solutes (dissolved organic carbon [DOC], dissolved organic nitrogen [DON], NH4+, NO3-, PO43-, K+, and SO42-). We analyze C-Q relationships using power law equations and a solute production model and use principal component analysis to test hypotheses regarding how the structure of the critical zone controls solute generation. Volcaniclastic watersheds had higher concentrations of weathering solutes and smaller tributaries were approximately threefold more efficient at generating these solutes than larger rivers. Lithology and vegetation explained a significant amount of variation in the theoretical maximum concentrations of weathering solutes (r2 = 0.43-0.48) and in the C-Q relationships of PO43- (r2 = 0.63) and SiO2(aq) (r2 = 0.47). However, the direction and magnitude of these relationships varied. Across watersheds, various forms of N and P displayed variable C-Q relationships, while DOC was consistently enriched with increasing discharge. Results suggest that PO43- may be a useful indicator of watershed function. Relationships between C-Q and landscape characteristics indicate the extent to which the structure and function of the Critical zone controls watershed solute fluxes.

  12. Structure-function relationships in highly modified shoots of cactaceae.

    Science.gov (United States)

    Mauseth, James D

    2006-11-01

    Cacti are extremely diverse structurally and ecologically, and so modified as to be intimidating to many biologists. Yet all have the same organization as most dicots, none differs fundamentally from Arabidopsis or other model plants. This review explains cactus shoot structure, discusses relationships between structure, ecology, development and evolution, and indicates areas where research on cacti is necessary to test general theories of morphogenesis. Cactus leaves are diverse; all cacti have foliage leaves; many intermediate stages in evolutionary reduction of leaves are still present; floral shoots often have large, complex leaves whereas vegetative shoots have microscopic leaves. Spines are modified bud scales, some secrete sugar as extra-floral nectaries. Many cacti have juvenile/adult phases in which the flowering adult phase (a cephalium) differs greatly from the juvenile; in some, one side of a shoot becomes adult, all other sides continue to grow as the juvenile phase. Flowers are inverted: the exterior of a cactus 'flower' is a hollow vegetative shoot with internodes, nodes, leaves and spines, whereas floral organs occur inside, with petals physically above stamens. Many cacti have cortical bundles vascularizing the cortex, however broad it evolves to be, thus keeping surface tissues alive. Great width results in great weight of weak parenchymatous shoots, correlated with reduced branching. Reduced numbers of shoot apices is compensated by great increases in number of meristematic cells within individual SAMs. Ribs and tubercles allow shoots to swell without tearing during wet seasons. Shoot epidermis and cortex cells live and function for decades then convert to cork cambium. Many modifications permit water storage within cactus wood itself, adjacent to vessels.

  13. Relationship between serum levels of oxidation and inflammatory factors in type 2 diabetic patients with retinopathy and its clinical significance

    Directory of Open Access Journals (Sweden)

    Fang Xu

    2018-02-01

    Full Text Available AIM: To investigate the relationship between serum levels of oxidation and inflammatory factors in type 2 diabetic patients with retinopathy and its clinical significance. METHODS: Totally 54 cases of patients with diabetic retinopathy was selected as subjects, including 31 patients with diabetes and non-proliferative retinopathy(NPDR groupand 23 patients with diabetes and proliferative retinopathy(PDR group. Another 30 cases of diabetes patients without DR(DM groupand 30 normal people(NC groupwas selected as control. The level of fasting blood glucose(FPG, 2h postprandial blood glucose(2hPG, glycosylated hemoglobin(HbA1c, serum malondialdehyde(MDAand heme oxygenase -1(HO-1, tumor necrosis factor α(TNF-αand interleukin-6(IL-6and C reactive protein(CRPwas detected, and variance test detect the difference between 4 groups, and SNK-Q was used to multiple comparison. Pearson correlation analysis was used to compare the correlation between oxidation markers(MDA and Ho-1and the level of inflammatory factors(TNF-α, IL-6 and CRP. COX multivariate analysis was used to investigate the risk and protective factors of diabetic retinopathy. RESULTS: The levels of FPG, 2hPG, HbA1c, MDA, TNF-α, IL-6 and CRP in DM group, PDR group and NPDR group were significantly higher than that in NC group(PPPPPPPPCONCLUSION: Oxidative stress is closely related to the expression of inflammatory factors in serum of patients with diabetes mellitus, and is an important risk factor of DR, and related indicators can be used as markers for DR diagnosis.

  14. Functional relationships between plasmids and their significance for metabolism and symbiotic performance of Rhizobium leguminosarum bv. trifolii.

    Science.gov (United States)

    Stasiak, Grażyna; Mazur, Andrzej; Wielbo, Jerzy; Marczak, Małgorzata; Zebracki, Kamil; Koper, Piotr; Skorupska, Anna

    2014-11-01

    Rhizobium leguminosarum bv. trifolii TA1 (RtTA1) is a soil bacterium establishing a highly specific symbiotic relationship with clover, which is based on the exchange of molecular signals between the host plant and the microsymbiont. The RtTA1 genome is large and multipartite, composed of a chromosome and four plasmids, which comprise approximately 65 % and 35 % of the total genome, respectively. Extrachromosomal replicons were previously shown to confer significant metabolic versatility to bacteria, which is important for their adaptation in the soil and nodulation competitiveness. To investigate the contribution of individual RtTA1 plasmids to the overall cell phenotype, metabolic properties and symbiotic performance, a transposon-based elimination strategy was employed. RtTA1 derivatives cured of pRleTA1b or pRleTA1d and deleted in pRleTA1a were obtained. In contrast to the in silico predictions of pRleTA1b and pRleTA1d, which were described as chromid-like replicons, both appeared to be completely curable. On the other hand, for pRleTA1a (symbiotic plasmid) and pRleTA1c, which were proposed to be unessential for RtTA1 viability, it was not possible to eliminate them at all (pRleTA1c) or entirely (pRleTA1a). Analyses of the phenotypic traits of the RtTA1 derivatives obtained revealed the functional significance of individual plasmids and their indispensability for growth, certain metabolic pathways, production of surface polysaccharides, autoaggregation, biofilm formation, motility and symbiotic performance. Moreover, the results allow us to suggest broad functional cooperation among the plasmids in shaping the phenotypic properties and symbiotic capabilities of rhizobia.

  15. Application of Bioorganic Fertilizer Significantly Increased Apple Yields and Shaped Bacterial Community Structure in Orchard Soil.

    Science.gov (United States)

    Wang, Lei; Li, Jing; Yang, Fang; E, Yaoyao; Raza, Waseem; Huang, Qiwei; Shen, Qirong

    2017-02-01

    Application of bioorganic fertilizers has been reported to improve crop yields and change soil bacterial community structure; however, little work has been done in apple orchard soils where the biological properties of the soils are being degraded due to long-term application of chemical fertilizers. In this study, we used Illumina-based sequencing approach to characterize the bacterial community in the 0-60-cm soil profile under different fertilizer regimes in the Loess Plateau. The experiment includes three treatments: (1) control without fertilization (CK); (2) application of chemical fertilizer (CF); and (3) application of bioorganic fertilizer and organic-inorganic mixed fertilizer (BOF). The results showed that the treatment BOF increased the apple yields by 114 and 67 % compared to the CK and CF treatments, respectively. The treatment BOF also increased the soil organic matter (SOM) by 22 and 16 % compared to the CK and CF treatments, respectively. The Illumina-based sequencing showed that Acidobacteria and Proteobacteria were the predominant phyla and Alphaproteobacteria and Gammaproteobacteria were the most abundant classes in the soil profile. The bacterial richness for ACE was increased after the addition of BOF. Compared to CK and CF treatments, BOF-treated soil revealed higher abundance of Proteobacteria, Alphaproteobacteria and Gammaproteobacteria, Rhizobiales, and Xanthomonadales while Acidobacteria, Gp7, Gp17, and Sphaerobacter were found in lower abundance throughout the soil profile. Bacterial community structure varied with soil depth under different fertilizer treatments, e.g., the bacterial richness, diversity, and the relative abundance of Verruccomicrobia, Candidatus Brocadiales, and Skermanella were decreased with the soil depth in all three treatments. Permutational multivariate analysis showed that the fertilizer regime was the major factor than soil depth in the variations of the bacterial community composition. Two groups, Lysobacter

  16. Structure-activity relationship of surfactant for preparing DMFC anodic catalyst

    International Nuclear Information System (INIS)

    Su Yi; Xue Xinzhong; Xu Weilin; Liu Changpeng; Xing Wei; Zhou Xiaochun; Tian Tian; Lu Tianhong

    2006-01-01

    Three kinds of surfactants as stabilizer were applied to the preparation of electrocatalysts for direct methanol fuel cell (DMFC). The catalysts have been characterized by examining their catalytic activities, morphologies and particle sizes by means of cyclic voltammetry, chronoamperometry, X-ray diffraction and transmission electron microscopy (TEM). It is found that the surfactants with different structures have a significantly influence on the catalyst shape and activity. The catalysts prepared with non-ionic surfactants as the stabilizer show higher activity for direct oxidation of methanol. The structure-activity relationship (SAR) analysis has been explored and the effect of hydrophile-lipophile balance (HLB value) has also been discussed

  17. The Relationship between Corporate Performance and Ownership Structure: Evidence from Turkey

    Directory of Open Access Journals (Sweden)

    Hicabi Ersoy

    2015-11-01

    Full Text Available This study investigates the effects of ownership structure on the performance of the listed companies in Borsa Istanbul Stock Exchange 30 Firms (BIST 30. The main hypothesis of our study is that there is a significant relationship between companies' performances and their ownership structures.The statistical population includes 19 non-financial companies in the period of years between 2008 and 2013. The results show that the concentration of the large shares of companies one or a few share holders has a negative effect on related firm’s performance.

  18. Investigating the Structure-Activity Relationship of the Insecticidal Natural Product Rocaglamide.

    Science.gov (United States)

    Hall, Roger G; Bruce, Ian; Cooke, Nigel G; Diorazio, Louis J; Cederbaum, Fredrik; Dobler, Markus R; Irving, Ed

    2017-12-01

    The natural product Rocaglamide (1), isolated from the tree Aglaia elliptifolia, is a compelling but also challenging lead structure for crop protection. In laboratory assays, the natural product shows highly interesting insecticidal activity against chewing pests and beetles, but also phytotoxicity on some crop plants. Multi-step syntheses with control of stereochemistry were required to probe the structure-activity relationship (SAR), and seek simplified analogues. After a significant research effort, just two areas of the molecule were identified which allow modification whilst maintaining activity, as will be highlighted in this paper.

  19. Scientific habits of mind: A reform of structure and relationships

    Science.gov (United States)

    Mooney, Linda Beth

    This research was designed to broaden current elementary science reform efforts by including the voices of our young scientists. Ten high school students who were defined as possessing both coherent science knowledge and scientific habits of mind were selected for the study. Through a three-part series of in-depth, phenomenological interviews, these students revealed early childhood experiences from birth through age ten to which they attributed their development of science knowledge and scientific habits of mind. Educational connoisseurship and criticism provided the framework through which the experiences were analyzed. The research revealed the overwhelming role of scientific habits of mind in the current success of these young scientists. Scientific habits of mind were developed through the structures and relationships in the home. Parents of the participants provided a non-authoritarian, fun, playful, tolerant atmosphere in which messes and experimentation were the norm. Large blocks of uninterrupted, unstructured time and space that "belonged" to the child allowed these children to follow where curiosity led. Frequently, the parent modeled scientific habits of mind. Good discipline in the minds of these families had nothing to do with punishments, rewards, or rules. The parents gave the children responsibilities, "free rein," and their trust, and the children blossomed in that trust and mutual respect. Parents recognized and supported the uniqueness, autonomy, interests, and emotions of the child. Above all, the young scientists valued the time, freedom, patience, and emotional support provided by their parents. For girls, construction toys, hot wheels, sand boxes, and outdoor experiences were particularly important. Art classes, free access to art media, sewing, music, and physical activity facilitated observational skills and spatial relationship development. The girls knew that doing traditionally masculine and feminine activities were acceptable and

  20. Structural Characteristics of Paleozoic and Geological Significance of Oil and Gas of Dongpu Depression

    Institute of Scientific and Technical Information of China (English)

    杨世刚

    2003-01-01

    The Dongpu depression has experienced a complicated evolution of structure since Mesozoic. The Paleozoic carbonate rock has been strongly reformed and the buried hills with different characteristics of structure are developed in the depression. There exist lots of groups of fault structures with strikes of NNE(or NE),NW, near NS and EW etc., of which the faults with strikes of NNE and NW play an important controlling role on present-day structural framework of the depression. The faults with near NS-striking and EW-striking deeply affect the establishment of structural framework of basement of the depression. Although most of the fractures are filled by calcite and other minerals, under the action of later structural stress, the earlier fractures could change their features into tensional ones. Therefore, much attention should be paid to the exploration and exploitation of Paleozoic oil and gas in Dongpu depression.

  1. Establishing collaborative structures and relationships: Teacher leaders' experiences

    Science.gov (United States)

    Canizo, Thea Lynne

    2002-04-01

    The purpose of this study was to explore teacher leaders' experiences as they attempted to establish collaborative structures and relationships resulting in improved science instruction at their schools. Teacher leaders were middle school science facilitators, full-time classroom teachers who acted as liaisons between the science teachers at their schools and a change initiative funded by the National Science Foundation. This was a qualitative study, using interviews to create a case study. The researcher used a three-part interview design developed by Seidman (1991). Six research questions served as a framework for the data analysis. Participants identified the following as factors which contributed to their success: support from the principal, other science teachers, central staff personnel, and the district-wide group of science facilitators; professional development; and the successful completion of a scope and sequence for science instruction. Factors identified as hindering their success were: lack of support or conflict with the principal; resistance to change; time constraints; a district policy which limited meeting time; teacher and administrator turnover; tension between the middle school and junior high school models; and personal doubts. From descriptions of their understanding and exercising of leadership, the researcher concluded that teacher leaders had become empowered. The school culture was seen to have a great effect on teacher leaders. The contrasts between a school with a positive culture and another school in disarray were presented. Structures such as summer institutes and release time during the school day were identified as critical for giving teachers the time needed to establish more collaborative working relationships. Once greater trust and understanding were present, teachers were better able to examine their teaching practices more critically. Participants identified mentoring of new members, a continuing role for science

  2. Using structural equation modeling to investigate relationships among ecological variables

    Science.gov (United States)

    Malaeb, Z.A.; Kevin, Summers J.; Pugesek, B.H.

    2000-01-01

    Structural equation modeling is an advanced multivariate statistical process with which a researcher can construct theoretical concepts, test their measurement reliability, hypothesize and test a theory about their relationships, take into account measurement errors, and consider both direct and indirect effects of variables on one another. Latent variables are theoretical concepts that unite phenomena under a single term, e.g., ecosystem health, environmental condition, and pollution (Bollen, 1989). Latent variables are not measured directly but can be expressed in terms of one or more directly measurable variables called indicators. For some researchers, defining, constructing, and examining the validity of latent variables may be the end task of itself. For others, testing hypothesized relationships of latent variables may be of interest. We analyzed the correlation matrix of eleven environmental variables from the U.S. Environmental Protection Agency's (USEPA) Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) using methods of structural equation modeling. We hypothesized and tested a conceptual model to characterize the interdependencies between four latent variables-sediment contamination, natural variability, biodiversity, and growth potential. In particular, we were interested in measuring the direct, indirect, and total effects of sediment contamination and natural variability on biodiversity and growth potential. The model fit the data well and accounted for 81% of the variability in biodiversity and 69% of the variability in growth potential. It revealed a positive total effect of natural variability on growth potential that otherwise would have been judged negative had we not considered indirect effects. That is, natural variability had a negative direct effect on growth potential of magnitude -0.3251 and a positive indirect effect mediated through biodiversity of magnitude 0.4509, yielding a net positive total effect of 0

  3. Sustainable Corporate Social Media Marketing Based on Message Structural Features: Firm Size Plays a Significant Role as a Moderator

    OpenAIRE

    Moon Young Kang; Byungho Park

    2018-01-01

    Social media has been receiving attention as a cost-effective tool to build corporate brand image and to enrich customer relationships. This phenomenon calls for more attention to developing a model that measures the impact of structural features, used in corporate social media messages. Based on communication science, this study proposes a model to measure the impact of three essential message structural features (interactivity, formality, and immediacy) in corporate social media on customer...

  4. Equation of state for sub-stoichiometric urania using significant structures theory

    International Nuclear Information System (INIS)

    Fischer, E.A.

    1979-01-01

    The Significant Structures Theory (SST) by Eyring was successfully used to predict the equation of state in the liquid range for a variety of materials, including UO 2 . However, all these applications assumed that the liquid evaporates congruently i.e. the composition of the vapor phase is identical to that of the condensed phase. In this paper, an attempt is made to apply SST to non-congruently evaporating materials, using hypo-stoichiometric urania as an example. To this end, additional hypotheses to those of the original SST must be made. In the SST, it is assumed that the partition function of the liquid can be expressed by suitably combining that of 'solidlike molecules', and of 'gaslike molecules'. In the present work, starting from the fact that non-stoichiometry of solid urania is connected with lattice defects (e.g. oxygen interstitials or oxygen vacancies), it is assumed that a simple oxygen defect model can be extrapolated into the liquid state. Thus, the solidlike partition function includes a defect term, which determines the O/U; the defect concentration depends on the absolute activity of oxygen. The gaslike partition function allows for UO(g) and UO 2 (g), the ratio depending also on the oxygen activity. The parameters of the theory are selected such as to obtain agreement with experimental data at the melting point. The physical requirement that the difference between liquid and gas disappears at the critical temperature necessitates an adjustment of the solidlike partition function at high temperatures. (orig.) [de

  5. The significance of crystalline/chrysalis structures in the diagnosis of melanocytic and nonmelanocytic lesions.

    Science.gov (United States)

    Balagula, Yevgeniy; Braun, Ralph P; Rabinovitz, Harold S; Dusza, Stephen W; Scope, Alon; Liebman, Tracey N; Mordente, Ines; Siamas, Katherine; Marghoob, Ashfaq A

    2012-08-01

    Crystalline/chrysalis structures (CS) are white shiny streaks that can only be seen with polarized dermatoscopy. We sought to estimate the prevalence and assess the clinical significance of CS in melanocytic and nonmelanocytic lesions. This was a prospective observational study in which dermatoscopic assessment of lesions was recorded in consecutive patients examined during a 6-month period. In addition, a data set of biopsy-proven melanomas was retrospectively analyzed. In all, 11,225 lesions in 881 patients were prospectively examined. Retrospectively, 229 melanomas imaged with polarized dermatoscopy were analyzed. In the prospective data set, a median of 12.7 lesions (range, 1-54) were evaluated per patient. None of clinically diagnosed Clark nevi (n = 9750, 86.8%) demonstrated CS. Overall, CS were observed in 206 (1.8%) lesions, most commonly dermatofibromas and scars among nonbiopsied lesions. A total of 265 (2.4%) lesions were biopsied, including 20 melanomas and 36 nevi. Among biopsied malignant lesions, CS were most commonly observed in basal cell carcinoma (47.6%) and invasive melanomas (84.6%). Melanomas were more likely to have CS than biopsied nevi (odds ratio = 9.7, 95% confidence interval 2.7-34.1). In the retrospective data set, CS were more commonly observed among invasive melanomas (41%) compared with in situ melanomas (17%) (odds ratio = 3.4, 95% confidence interval 1.9-6.3, P < .001). The prevalence of CS correlated with increased melanoma thickness (P = .001). Biopsied lesions represent a small percentage of the total number of lesions evaluated. Among biopsied malignant lesions, CS are most commonly observed in basal cell carcinoma and invasive melanomas and rarely seen in nevi. In melanoma, CS may reflect increased tumor thickness and progression. Copyright © 2011 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  6. Structure-function relationships during segregated and integrated network states of human brain functional connectivity.

    Science.gov (United States)

    Fukushima, Makoto; Betzel, Richard F; He, Ye; van den Heuvel, Martijn P; Zuo, Xi-Nian; Sporns, Olaf

    2018-04-01

    Structural white matter connections are thought to facilitate integration of neural information across functionally segregated systems. Recent studies have demonstrated that changes in the balance between segregation and integration in brain networks can be tracked by time-resolved functional connectivity derived from resting-state functional magnetic resonance imaging (rs-fMRI) data and that fluctuations between segregated and integrated network states are related to human behavior. However, how these network states relate to structural connectivity is largely unknown. To obtain a better understanding of structural substrates for these network states, we investigated how the relationship between structural connectivity, derived from diffusion tractography, and functional connectivity, as measured by rs-fMRI, changes with fluctuations between segregated and integrated states in the human brain. We found that the similarity of edge weights between structural and functional connectivity was greater in the integrated state, especially at edges connecting the default mode and the dorsal attention networks. We also demonstrated that the similarity of network partitions, evaluated between structural and functional connectivity, increased and the density of direct structural connections within modules in functional networks was elevated during the integrated state. These results suggest that, when functional connectivity exhibited an integrated network topology, structural connectivity and functional connectivity were more closely linked to each other and direct structural connections mediated a larger proportion of neural communication within functional modules. Our findings point out the possibility of significant contributions of structural connections to integrative neural processes underlying human behavior.

  7. Structural protein relationships among eastern equine encephalitis viruses.

    Science.gov (United States)

    Strizki, J M; Repik, P M

    1994-11-01

    We have re-evaluated the relationships among the polypeptides of eastern equine encephalitis (EEE) viruses using SDS-PAGE and peptide mapping of individual virion proteins. Four to five distinct polypeptide bands were detected upon SDS-PAGE analysis of viruses: the E1, E2 and C proteins normally associated with alphavirus virions, as well as an additional more rapidly-migrating E2-associated protein and a high M(r) (HMW) protein. In contrast with previous findings by others, the electrophoretic profiles of the virion proteins of EEE viruses displayed a marked correlation with serotype. The protein profiles of the 33 North American (NA)-serotype viruses examined were remarkably homogeneous, with variation detected only in the E1 protein of two isolates. In contrast, considerable heterogeneity was observed in the migration profiles of both the E1 and E2 glycoproteins of the 13 South American (SA)-type viruses examined. Peptide mapping of individual virion proteins using limited proteolysis with Staphylococcus aureus V8 protease confirmed that, in addition to the homogeneity evident among NA-type viruses and relative heterogeneity among SA-type viruses, the E1 and E2 proteins of NA- and SA-serotype viruses exhibited serotype-specific structural variation. The C protein was highly conserved among isolates of both virus serotypes. Endoglycosidase analyses of intact virions did not reveal substantial glycosylation differences between the glycoproteins of NA- and SA-serotype viruses. Both the HMW protein and the E2 protein (doublet) of EEE virus appeared to contain, at least in part, high-mannose type N-linked oligosaccharides. No evidence of O-linked glycans was found on either the E1 or the E2 glycoprotein. Despite the observed structural differences between proteins of NA- and SA-type viruses, Western blot analyses utilizing polyclonal antibodies indicated that immunoreactive epitopes appeared to be conserved.

  8. Quantitative structure-cytotoxicity relationship of phenylpropanoid amides.

    Science.gov (United States)

    Shimada, Chiyako; Uesawa, Yoshihiro; Ishihara, Mariko; Kagaya, Hajime; Kanamoto, Taisei; Terakubo, Shigemi; Nakashima, Hideki; Takao, Koichi; Saito, Takayuki; Sugita, Yoshiaki; Sakagami, Hiroshi

    2014-07-01

    A total of 12 phenylpropanoid amides were subjected to quantitative structure-activity relationship (QSAR) analysis, based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to investigate on their biological activities. Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and three human oral normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor selectivity was evaluated by the ratio of the mean CC50 (50% cytotoxic concentration) against normal oral cells to that against OSCC cell lines. Anti-HIV activity was evaluated by the ratio of CC50 to EC50 (50% cytoprotective concentration from HIV infection). Physicochemical, structural, and quantum-chemical parameters were calculated based on the conformations optimized by the LowModeMD method followed by density functional theory (DFT) method. Twelve phenylpropanoid amides showed moderate cytotoxicity against both normal and OSCC cell lines. N-Caffeoyl derivatives coupled with vanillylamine and tyramine exhibited relatively higher tumor selectivity. Cytotoxicity against normal cells was correlated with descriptors related to electrostatic interaction such as polar surface area and chemical hardness, whereas cytotoxicity against tumor cells correlated with free energy, surface area and ellipticity. The tumor-selective cytotoxicity correlated with molecular size (surface area) and electrostatic interaction (the maximum electrostatic potential). The molecular size, shape and ability for electrostatic interaction are useful parameters for estimating the tumor selectivity of phenylpropanoid amides. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  9. Quantitative structure-toxicity relationship study of some natural and synthetic coumarins using retention parameters

    Directory of Open Access Journals (Sweden)

    Rabtti El Hadi M.A.

    2012-01-01

    Full Text Available Four lipophilicity descriptors (RM0, b, C0, PC1 for twelve coumarine derivatives were determined by reversed-phase thin-layer chromatography in order to analyze which descriptor best describes the lipophilicity of coumarines investigated. Moreover, possible chemical toxicity of coumarins, expressed as the probability of a compound to cause organ-specific health effects, was calculated using ACD/Tox Suite program. The quantitative relationships between toxicity and molecular descriptors, including experimentally determined lipophilicity descriptors obtained in current study, were investigated using partial least square regression. The best models were obtained for kidney and liver health effects. Quantitative structure-toxicity relationship models revealed the importance of electric polarization descriptors, size descriptors and lipophilicity descriptors. Obtained models were used for the selection of the structural features of the compounds that are significantly affecting their absorption, distribution, metabolism, excretion, and toxicity. [Acknowledgements. This work has been supported by the Ministry of Education and Science of Serbia, Grant 172017.

  10. Designing a Quantitative Structure-Activity Relationship for the ...

    Science.gov (United States)

    Toxicokinetic models serve a vital role in risk assessment by bridging the gap between chemical exposure and potentially toxic endpoints. While intrinsic metabolic clearance rates have a strong impact on toxicokinetics, limited data is available for environmentally relevant chemicals including nearly 8000 chemicals tested for in vitro bioactivity in the Tox21 program. To address this gap, a quantitative structure-activity relationship (QSAR) for intrinsic metabolic clearance rate was developed to offer reliable in silico predictions for a diverse array of chemicals. Models were constructed with curated in vitro assay data for both pharmaceutical-like chemicals (ChEMBL database) and environmentally relevant chemicals (ToxCast screening) from human liver microsomes (2176 from ChEMBL) and human hepatocytes (757 from ChEMBL and 332 from ToxCast). Due to variability in the experimental data, a binned approach was utilized to classify metabolic rates. Machine learning algorithms, such as random forest and k-nearest neighbor, were coupled with open source molecular descriptors and fingerprints to provide reasonable estimates of intrinsic metabolic clearance rates. Applicability domains defined the optimal chemical space for predictions, which covered environmental chemicals well. A reduced set of informative descriptors (including relative charge and lipophilicity) and a mixed training set of pharmaceuticals and environmentally relevant chemicals provided the best intr

  11. 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.

  12. Structure-function relationship of skeletal muscle provides inspiration for design of new artificial muscle

    Science.gov (United States)

    Gao, Yingxin; Zhang, Chi

    2015-03-01

    A variety of actuator technologies have been developed to mimic biological skeletal muscle that generates force in a controlled manner. Force generation process of skeletal muscle involves complicated biophysical and biochemical mechanisms; therefore, it is impossible to replace biological muscle. In biological skeletal muscle tissue, the force generation of a muscle depends not only on the force generation capacity of the muscle fiber, but also on many other important factors, including muscle fiber type, motor unit recruitment, architecture, structure and morphology of skeletal muscle, all of which have significant impact on the force generation of the whole muscle or force transmission from muscle fibers to the tendon. Such factors have often been overlooked, but can be incorporated in artificial muscle design, especially with the discovery of new smart materials and the development of innovative fabrication and manufacturing technologies. A better understanding of the physiology and structure-function relationship of skeletal muscle will therefore benefit the artificial muscle design. In this paper, factors that affect muscle force generation are reviewed. Mathematical models used to model the structure-function relationship of skeletal muscle are reviewed and discussed. We hope the review will provide inspiration for the design of a new generation of artificial muscle by incorporating the structure-function relationship of skeletal muscle into the design of artificial muscle.

  13. Quantitative Structure ‒ Antiprotozoal Activity Relationships of Sesquiterpene Lactones

    Directory of Open Access Journals (Sweden)

    Reto Brun

    2009-06-01

    Full Text Available Prompted by results of our previous studies where we found high activity of some sesquiterpene lactones (STLs against Trypanosoma brucei rhodesiense (which causes East African sleeping sickness, we have now conducted a structure-(in-vitro-activity study on a set of 40 STLs against T. brucei rhodesiense, T. cruzi, Leishmania donovani and Plasmodium falciparum. Furthermore, cytotoxic activity against L6 rat skeletal myoblast cells was assessed. Some of the compounds possess high activity, especially against T. brucei (e.g. helenalin and some of its esters with IC50-values of 0.05-0.1 µM, which is about 10 times lower than their cytotoxic activity. It was found that all investigated antiprotozoal activities are significantly correlated with cytotoxicity and the major determinants for activity are a,b-unsaturated structural elements, also known to be essential for other biological activities of STLs. It was observed, however, that certain compounds are considerably more toxic against protozoa than against mammalian cells while others are more cytotoxic than active against the protozoa. A comparative QSAR analysis was therefore undertaken, in order to discern the antiparasitic activity of STLs against T. brucei and cytotoxicity. Both activities were found to depend to a large extent on the same structural elements and molecular properties. The observed variance in the biological data can be explained in terms of subtle variations in the relative influences of various molecular descriptors.

  14. Investigation of the relationship between structural empowerment and organizational commitment of nurses in Zanjan hospitals.

    Science.gov (United States)

    Eskandari, Fereidoun; Siahkali, Soheila Rabie; Shoghli, Alireza; Pazargadi, Mehrnoosh; Tafreshi, Mansoreh Zaghari

    2017-03-01

    The demanding nature of nursing work environments signals longstanding and growing concerns about nurses' health and job satisfaction and the provision of quality care. Specifically in health care settings, nurse leaders play an essential role in creating supportive work environments to avert these negative trends and increase nurse job satisfaction. The purpose of this study was to examine the relationship between structural empowerment and organizational commitment of nurses. 491 nurses working in Zanjan hospitals participated in this descriptive-correlational study in 2010. Tools for data collection were Meyer and Allen's organizational commitment questionnaire and "Conditions for Work Effectiveness Questionnaire-II" (CWEQ-II). Data was analyzed by SPSS16. The statistical tests such as variance analysis, t-test, pearson correlation coefficient and linear regression were used for data analysis. According to the findings, the perception of nurses working in hospitals on "Structural Empowerment" was moderate (15.98±3.29). Nurses believed "opportunity" as the most important element in structural empowerment with the score of 3.18 ±0.79. Nurses working in non-academic hospitals and in non-teaching hospitals had higher organizational commitment than others. There was a significant relationship between structural empowerment and organizational commitment. Generally, structural empowerment (relatively strong) correlates with nurses' organizational commitment. We concluded that a high structural empowerment increases the organizational commitment of nurses.

  15. Internal architecture, permeability structure, and hydrologic significance of contrasting fault-zone types

    Science.gov (United States)

    Rawling, Geoffrey C.; Goodwin, Laurel B.; Wilson, John L.

    2001-01-01

    The Sand Hill fault is a steeply dipping, large-displacement normal fault that cuts poorly lithified Tertiary sediments of the Albuquerque basin, New Mexico, United States. The fault zone does not contain macroscopic fractures; the basic structural element is the deformation band. The fault core is composed of foliated clay flanked by structurally and lithologically heterogeneous mixed zones, in turn flanked by damage zones. Structures present within these fault-zone architectural elements are different from those in brittle faults formed in lithified sedimentary and crystalline rocks that do contain fractures. These differences are reflected in the permeability structure of the Sand Hill fault. Equivalent permeability calculations indicate that large-displacement faults in poorly lithified sediments have little potential to act as vertical-flow conduits and have a much greater effect on horizontal flow than faults with fractures.

  16. Refinement of the Fe4Al13 structure and its relationship to the quasihomological homeotypical structures

    International Nuclear Information System (INIS)

    Grin, J.; Burkhardt, U.; Ellner, M.; Peters, K.

    1994-01-01

    The crystal structure of Fe 4 Al 13 was refined using single crystal diffractometer data: pearson symbol mC102, space group C2/m; a=15.492(2) A, b=8.078(2) A, c=12.471(1) A, β=107.69(1) ; R F =0.053, R F (w)=0.044 for 1127 reflections and 137 refined parameters. The coordination numbers of atoms are 9, 10, 11 for iron and 10, 12, 13, 14 for aluminium. The shortest interatomic distances are: Fe-Fe - 2.902 A, Fe-Al - 2.374 A, Al-Al - 2.533 A. A preferred occupation of pentagonal prismatic coordinated positions by aluminium was found. The structural relationship between the Fe 4 Al 13 structure and chemically homologous and homeotypical structures of aluminium and gallium containing systems with the 3d transition metals is discussed. The greatest similarity was found concerning the coordination polyhedra, especially that of transition metal atoms. The main common feature of these homeotypical structures is the presence of pentagonal ''channels'', which is strongly dependent on the chemical composition. With increasing atomic number of the 3d transition metal, the stability range of these structures shifts to the transition metal-rich concentration. It is concluded that there is a connection between the occurrence of aluminium and gallium-containing decagonal and icosahedral phases and the existence of the infinite one-dimensional pentagonal channels in the intermetallic compounds showing a similar chemical composition. (orig.)

  17. [Structural features of the pulp ground substance and its significance for acute and chronic pulpitis].

    Science.gov (United States)

    Davarashvili, Capital Ka Cyrillich; Dgebuadze, M; Melikadze, E; Zhvitiashvili, T; Jandieri, K

    2012-12-01

    The goal of the research study is an analysis of amorphous material, fibers and cellular elements of the dental pulp and evaluation of their interactions with a variety of fibrouse structures in the norm and inflammation. To solve this problem used dental pulp tissue bioptats (10 cases) of patients with acute and chronic pulpitis and 10 control specimens (orthodontic operations). The material was studied by histological and electron microscopic methods of research. It was determined that in acute pulpitis develope changes promoting dissociation of fibrouse and cellular structures of pulp components, and thus, loss the cementing binding role of the ground substance. Acute pulpitis characterized by the recruitment of mast cells. ; The reorganization and remodeling of ground substance associated with neoangiogenesis, especially capillaries, and the replacement of collagen fibers by the fibrouse structures are major points in chronic pulpitis.

  18. Quantitative structure carcinogenicity relationship for detecting structural alerts in nitroso-compounds

    International Nuclear Information System (INIS)

    Helguera, Aliuska Morales; Cordeiro, M. Natalia D.S.; Perez, Miguel Angel Cabrera; Combes, Robert D.; Gonzalez, Maykel Perez

    2008-01-01

    In this work, Quantitative Structure-Activity Relationship (QSAR) modelling was used as a tool for predicting the carcinogenic potency of a set of 39 nitroso-compounds, which have been bioassayed in male rats by using the oral route of administration. The optimum QSAR model provided evidence of good fit and performance of predicitivity from training set. It was able to account for about 84% of the variance in the experimental activity and exhibited high values of the determination coefficients of cross validations, leave one out and bootstrapping (q 2 LOO = 78.53 and q 2 Boot = 74.97). Such a model was based on spectral moments weighted with Gasteiger-Marsilli atomic charges, polarizability and hydrophobicity, as well as with Abraham indexes, specifically the summation solute hydrogen bond basicity and the combined dipolarity/polarizability. This is the first study to have explored the possibility of combining Abraham solute descriptors with spectral moments. A reasonable interpretation of these molecular descriptors from a toxicological point of view was achieved by means of taking into account bond contributions. The set of relationships so derived revealed the importance of the length of the alkyl chains for determining carcinogenic potential of the chemicals analysed, and were able to explain the difference between mono-substituted and di-substituted nitrosoureas as well as to discriminate between isomeric structures with hydroxyl-alkyl and alkyl substituents in different positions. Moreover, they allowed the recognition of structural alerts in classical structures of two potent nitrosamines, consistent with their biotransformation. These results indicate that this new approach has the potential for improving carcinogenicity predictions based on the identification of structural alerts

  19. The significance of the neurovascular structures passing through the spinoglenoid notch

    International Nuclear Information System (INIS)

    Atekin, Mustafa; Demiryiirek, Deniz; Bayramoglu, Alp; Tuccar, Eray

    2003-01-01

    To define the detailed anatomy of the neurovascular bundle at the spinoglenoid notch and to report the dimensions of these structures in cadavers. In the present study, the external diameters of suprascapular artery, vein and nerve were measured at the spinoglenoid region in 18 formalin fixed cadavers (36 soulders) by using a caliper. The study was carried out in the dissection laboratory of Anatomy Department of Hacettepe University ,Ankara University, Ankara and Mersin University ,Mersin,Turkey, between2002 and 2003.The average external diameter for suprascapular vein was 2.6 mmand nerve was 2.2 mm. The spinoglenoid notch was roofed by the spinoglenoid ligament and appeared as a fibroosseous foramen in all cadavers. We found that vascular structures (suprascapular artery and vein )occupied 68.5% and the suprascapular nerve occupied 31.5% of this foramen. Although the diameters of the vascular structures at the spinoglenoid notch measured by magnetic resonance imaging have been reported,to our knowledge, external diameters of these structures at the spinoglenoid notch have not been described in cadavers. We believe that detailed anatomy of suprascapular neurovascular bundle at the spinoglenoid notch should be appreciated for better understanding of risk factors possibly causing the sprascapular nerve entrapment syndrome specially for those who are involved in voilent ovehead sports activities such as volleyball and baseball. (author)

  20. Beyond Social Constructionism: A Structural Analysis of the Cultural Significance of the Child Star

    Science.gov (United States)

    O'Connor, Jane

    2009-01-01

    This article challenges the dominance of social constructionist theories of childhood by presenting a structural analysis of the child star as a recurrent, universal feature in the myths and legends of the world. The article argues that by conceptualising our understanding of children and childhood as being due solely to the socio-historical…

  1. Ageing of significant to safety structure elements of nuclear power plants

    International Nuclear Information System (INIS)

    Maksimovas, G.; Ramanauskiene, A.; Ziliukas, A.

    1999-01-01

    The paper analyzes the ageing problems of structure elements in nuclear power plants. The standard documents and principal parts of the ageing evaluation program are presented. The ageing evaluation model is being worked out and degradation mechanisms of different atomic reactor materials are being compared. (author)

  2. The Widespread Prevalence and Functional Significance of Silk-Like Structural Proteins in Metazoan Biological Materials.

    Directory of Open Access Journals (Sweden)

    Carmel McDougall

    Full Text Available In nature, numerous mechanisms have evolved by which organisms fabricate biological structures with an impressive array of physical characteristics. Some examples of metazoan biological materials include the highly elastic byssal threads by which bivalves attach themselves to rocks, biomineralized structures that form the skeletons of various animals, and spider silks that are renowned for their exceptional strength and elasticity. The remarkable properties of silks, which are perhaps the best studied biological materials, are the result of the highly repetitive, modular, and biased amino acid composition of the proteins that compose them. Interestingly, similar levels of modularity/repetitiveness and similar bias in amino acid compositions have been reported in proteins that are components of structural materials in other organisms, however the exact nature and extent of this similarity, and its functional and evolutionary relevance, is unknown. Here, we investigate this similarity and use sequence features common to silks and other known structural proteins to develop a bioinformatics-based method to identify similar proteins from large-scale transcriptome and whole-genome datasets. We show that a large number of proteins identified using this method have roles in biological material formation throughout the animal kingdom. Despite the similarity in sequence characteristics, most of the silk-like structural proteins (SLSPs identified in this study appear to have evolved independently and are restricted to a particular animal lineage. Although the exact function of many of these SLSPs is unknown, the apparent independent evolution of proteins with similar sequence characteristics in divergent lineages suggests that these features are important for the assembly of biological materials. The identification of these characteristics enable the generation of testable hypotheses regarding the mechanisms by which these proteins assemble and direct the

  3. Significance of shock structure on supersonic jet mixing noise of axisymmetric nozzles

    Science.gov (United States)

    Kim, Chan M.; Krejsa, Eugene A.; Khavaran, Abbas

    1994-09-01

    One of the key technical elements in NASA's high speed research program is reducing the noise level to meet the federal noise regulation. The dominant noise source is associated with the supersonic jet discharged from the engine exhaust system. Whereas the turbulence mixing is largely responsible for the generation of the jet noise, a broadband shock-associated noise is also generated when the nozzle operates at conditions other than its design. For both mixing and shock noise components, because the source of the noise is embedded in the jet plume, one can expect that jet noise can be predicted from the jet flowfield computation. Mani et al. developed a unified aerodynamic/acoustic prediction scheme by applying an extension of Reichardt's aerodynamic model to compute turbulent shear stresses which are utilized in estimating the strength of the noise source. Although this method produces a fast and practical estimate of the jet noise, a modification by Khavaran et al. has led to an improvement in aerodynamic solution. The most notable feature in this work is that Reichardt's model is replaced with the computational fluid dynamics (CFD) solution of Reynolds-averaged Navier-Stokes equations. The major advantage of this work is that the essential, noise-related flow quantities such as turbulence intensity and shock strength can be better predicted. The predictions were limited to a shock-free design condition and the effect of shock structure on the jet mixing noise was not addressed. The present work is aimed at investigating this issue. Under imperfectly expanded conditions the existence of the shock cell structure and its interaction with the convecting turbulence structure may not only generate a broadband shock-associated noise but also change the turbulence structure, and thus the strength of the mixing noise source. Failure in capturing shock structures properly could lead to incorrect aeroacoustic predictions.

  4. Verbal Memory Decline following DBS for Parkinson's Disease: Structural Volumetric MRI Relationships.

    Science.gov (United States)

    Geevarghese, Ruben; Lumsden, Daniel E; Costello, Angela; Hulse, Natasha; Ayis, Salma; Samuel, Michael; Ashkan, Keyoumars

    2016-01-01

    Parkinson's disease is a chronic degenerative movement disorder. The mainstay of treatment is medical. In certain patients Deep Brain Stimulation (DBS) may be offered. However, DBS has been associated with post-operative neuropsychology changes, especially in verbal memory. Firstly, to determine if pre-surgical thalamic and hippocampal volumes were related to verbal memory changes following DBS. Secondly, to determine if clinical factors such as age, duration of symptoms or motor severity (UPDRS Part III score) were related to verbal memory changes. A consecutive group of 40 patients undergoing bilateral Subthalamic Nucleus (STN)-DBS for PD were selected. Brain MRI data was acquired, pre-processed and structural volumetric data was extracted using FSL. Verbal memory test scores for pre- and post-STN-DBS surgery were recorded. Linear regression was used to investigate the relationship between score change and structural volumetric data. A significant relationship was demonstrated between change in List Learning test score and thalamic (left, p = 0.02) and hippocampal (left, p = 0.02 and right p = 0.03) volumes. Duration of symptoms was also associated with List Learning score change (p = 0.02 to 0.03). Verbal memory score changes appear to have a relationship to pre-surgical MRI structural volumetric data. The findings of this study provide a basis for further research into the use of pre-surgical MRI to counsel PD patients regarding post-surgical verbal memory changes.

  5. Reconstructing Data Flow Diagrams from Structure Charts Based on the Input and Output Relationship

    OpenAIRE

    YAMAMOTO, Shuichiro

    1995-01-01

    The traceability of data flow diagrams against structure charts is very important for large software development. Specifying if there is a relationship between a data flow diagram and a structure chart is a time consuming task. Existing CASE tools provide a way to maintain traceability. If we can extract the input-output relationship of a system from a structure chart, the corresponding data flow diagram can be automatically generated from the relationship. For example, Benedusi et al. propos...

  6. Perceived boundary of 'differences' and 'sameness' by Japanese students in Australia : Is difference in cultures a significant variable for constructing interpersonal relationship?

    OpenAIRE

    小柳, 志津

    2003-01-01

    Thirty-one Japanese undergraduate and postgraduate students in Australian universities participated in semi-structured interviews to examine the interpersonal relationships between Japanese students and other nationalities in Australia, in particular, Australians and other international students. It was found that the Japanese students tended to form closer relationships and feel more comfortable in communicating with other Asian students than Australians, and that many regard Asian students ...

  7. Incidence and significance of cystic structures in the ovaries of gadoid fish

    Directory of Open Access Journals (Sweden)

    Rosario Domínguez-Petit

    2011-06-01

    Full Text Available Fish regulate egg production by atresia. Sometimes, oocytes are encapsulated in cystic structures that might remain in the ovary for months, altering female reproductive potential in future spawning seasons. Ovaries of Atlantic cod (Gadus morhua, L. from the Flemish Cap and European hake (Merluccius merluccius, L. from the Galician Shelf (NW Spain were analysed from 1999 to 2006. The prevalence and abundance of ovarian cysts were estimated. Cyst prevalence increased with female size and/or age for both species, and decreased with high condition factor in hake. Cyst intensity does not correlate with any analysed factor. The size/age structure of spawning stock biomass and female condition could affect the prevalence of cysts in the ovaries, though it does not seem to affect cyst intensity in the ovary. Further research is needed to determine cyst resorption time and the impact that it has on egg production and consequently on stock reproductive potential.

  8. OBSERVATION ON ARRANGEMENT OF HILAR STRUCTURES IN CADAVERIC KIDNEYS AND THEIR CLINICAL SIGNIFICANCE

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar Sinha

    2014-12-01

    Full Text Available Hilum of an organ is a depression, pit or slit like opening through which vital structures enter or leave the organ. In addition to the kidney, hilum is also observed in the cerebellum, lung, ovary, spleen and suprarenal gland. Laparoscopic nephron-sparing surgery for solid renal masses can be achieved successfully both transperitoneally and retroperitoneally if a comprehensive knowledge of both normal and variant hilar anatomy of the kidneys is in the mind of the operating surgeon. Documented text is available on various aspects of the kidneys but an observation on variations in hilar arrangement is infrequently cited. In standard text from anterior to posterior the structures at the renal hilum are renal vein, renal artery and the renal pelvis.

  9. Coastal structural remains on the east coast of India: Evidence of maritime activities and their significance

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.

    , Masulipatnam and Nagapattanam. On the other hand, Dronimukha refers to a port situated near the confluence of the river and the sea. Dronimukha was also a market place. Interestingly, the ports such as Dwarka, Tondi and Puhar also had the same meaning... and these port towns had well-established markets and hinterland connections (Roy 1994). Besides the geographical considerations in the location of ports, the maritime structures such as boatbuilding yards, landing places, boat shelters, causeways, wharves...

  10. Significance of Objective Structured Clinical Examinations to Plastic Surgery Residency Training.

    Science.gov (United States)

    Simmons, Brian J; Zoghbi, Yasmina; Askari, Morad; Birnbach, David J; Shekhter, Ilya; Thaller, Seth R

    2017-09-01

    Objective structured clinical examinations (OSCEs) have proven to be a powerful tool. They possess more than a 30-year track record in assessing the competency of medical students, residents, and fellows. Objective structured clinical examinations have been used successfully in a variety of medical specialties, including surgery. They have recently found their way into the subspecialty of plastic surgery. This article uses a systematic review of the available literature on OSCEs and their recent use in plastic surgery. It incorporates survey results assessing program directors' views on the use of OSCEs. Approximately 40% of programs surveyed use OSCEs to assess the Accreditation Council for Graduate Medical Education core competencies. We found that 40% use OSCEs to evaluate specific plastic surgery milestones. Objective structured clinical examinations are usually performed annually. They cost anywhere between $100 and more than $1000 per resident. Four milestones giving residents the most difficulties on OSCEs were congenital anomalies, noncancer breast surgery, breast reconstruction, and practice-based learning and improvement. It was determined that challenges with milestones were due to lack of adequate general knowledge and surgical ward patient care, as well as deficits in professionalism and system-based problems. Programs were able to remediate weakness found by OSCEs using a variety of methods. Objective structured clinical examinations offer a unique tool to objectively assess the proficiency of residents in key areas of the Accreditation Council for Graduate Medical Education core competencies. In addition, they can be used to assess the specific milestones that plastic surgery residents must meet. This allows programs to identify and improve identified areas of weakness.

  11. Significant Structuring Resources in the Reading Practices of a Digital Classroom

    Directory of Open Access Journals (Sweden)

    Annika Lantz-Andersson

    2016-06-01

    Full Text Available Since reading and writing digitally demand partially different competencies, there is a change in some of the premises of related educational practices. This study aims to contribute to the knowledge of educational reading practices by scrutinizing how literacy events evolve in a digital classroom where each student has a personal digital device (1:1, iPads in this study. Our study is grounded in sociocultural theories of learning and focuses on the structuring resources utilized by students, namely the notion of multiple ongoing activities and the ways in which specific resources take precedence in shaping these activities. One class of 13–14 year-old students was studied for a week across several subjects through video-recordings and observations. The findings imply that the students moved among vast array of reading practices. However, the main structuring resource is a strong focus on task-solving and the practice of schooling, which mainly builds on principles emanating from traditional text. It is only occasionally that structuring resources that also include the opportunities associated with digital technology are utilized. This indicates the importance of further studies on how educational practices could be organized to scaffold the basis of traditional reading comprehension as well as other approaches required in digital environments.

  12. A Limited Structural Modification Results in a Significantly More Efficacious Diazachrysene-Based Filovirus Inhibitor

    Directory of Open Access Journals (Sweden)

    Rekha G. Panchal

    2012-08-01

    Full Text Available Ebola (EBOV and Marburg (MARV filoviruses are highly infectious pathogens causing deadly hemorrhagic fever in humans and non-human primates. Promising vaccine candidates providing immunity against filoviruses have been reported. However, the sporadic nature and swift progression of filovirus disease underlines the need for the development of small molecule therapeutics providing immediate antiviral effects. Herein we describe a brief structural exploration of two previously reported diazachrysene (DAAC-based EBOV inhibitors. Specifically, three analogs were prepared to examine how slight substituent modifications would affect inhibitory efficacy and inhibitor-mediated toxicity during not only EBOV, but also MARV cellular infection. Of the three analogs, one was highly efficacious, providing IC50 values of 0.696 µM ± 0.13 µM and 2.76 µM ± 0.21 µM against EBOV and MARV infection, respectively, with little or no associated cellular toxicity. Overall, the structure-activity and structure-toxicity results from this study provide a framework for the future development of DAAC-based filovirus inhibitors that will be both active and non-toxic in vivo.

  13. Structure modification and functionality of whey proteins: quantitative structure-activity relationship approach.

    Science.gov (United States)

    Nakai, S; Li-Chan, E

    1985-10-01

    According to the original idea of quantitative structure-activity relationship, electric, hydrophobic, and structural parameters should be taken into consideration for elucidating functionality. Changes in these parameters are reflected in the property of protein solubility upon modification of whey proteins by heating. Although solubility is itself a functional property, it has been utilized to explain other functionalities of proteins. However, better correlations were obtained when hydrophobic parameters of the proteins were used in conjunction with solubility. Various treatments reported in the literature were applied to whey protein concentrate in an attempt to obtain whipping and gelling properties similar to those of egg white. Mapping simplex optimization was used to search for the best results. Improvement in whipping properties by pepsin hydrolysis may have been due to higher protein solubility, and good gelling properties resulting from polyphosphate treatment may have been due to an increase in exposable hydrophobicity. However, the results of angel food cake making were still unsatisfactory.

  14. MEDITERRANEAN FOREST TREE DECLINE IN ITALY: RELATIONSHIPS BETWEEN DROUGHT, POLLUTANTS AND THE WAX STRUCTURE OF LEAVES

    Directory of Open Access Journals (Sweden)

    E. PAOLETTI

    1996-04-01

    Full Text Available After presenting the situation of forest decline in Italy and analyzing the factors that play a contributing role, tbis paper studies the response of the epicuticular wax structures and the stomata in ten broadleaf species and one conifer to fog-like treatments with acids andlor surfactants and to severe water stress. The main results are that wax structure alterations vary in intensity in the different species studied and that the microstructural alterations observed in field conditions cannot be attributed only to severe drought. since sample trccs put through water stress simulations do nol differ significantly from controls. In the artificial surfactant treatment, a positive relationship between structural damage to tbe stomata and transpiration suggests possible synergies between the effects of drought and those of pollutants in inducing stress conditions in Mediterranean vegetation.

  15. The significance of the structural regularity for the seismic response of buildings

    International Nuclear Information System (INIS)

    Hampe, E.; Goldbach, R.; Schwarz, J.

    1991-01-01

    The paper gives an state-of-the-art report about the international design practice and submits fundamentals for a systematic approach to the solution of that problem. Different criteria of regularity are presented and discussed with respect to EUROCODE Nr. 8. Still remaining questions and the main topics of future research activities are announced and come into consideration. Frame structures with or without additional stiffening wall elements are investigated to illustrate the qualitative differences of the vibrational properties and the earthquake response of regular and irregular systems. (orig./HP) [de

  16. Still a Special Relationship? The Significance of United States-United Kingdom Relations in the Twenty-First Century

    Science.gov (United States)

    2011-12-01

    Anglo - Saxon ally over Nasser and the canal.55 In 2010, in a speech at Chatham House, Liberal Democrat Nick Clegg suggested that “what...strategic culture, and as an expression of shared values and institutions the character of which is vital for those charged with service in an Anglo ...American context as well as NATO. 14. SUBJECT TERMS United Kingdom, United States, Special Relationship, Anglo - American Relations, Iraq, Afghanistan

  17. Finescale Structure of the Temperature-Salinity Relationship

    National Research Council Canada - National Science Library

    Polzin, Kurt L; Ferrari, Raffaele

    2005-01-01

    The long term goal of this project is to understand the processes that establish the temperature-salinity relationship in the ocean, with emphasis on the interplay between advection at the large scale...

  18. Relationship between pore structure and compressive strength of ...

    Indian Academy of Sciences (India)

    J BU

    compressive strength relationship in ... He applied this equation to experimental data on gypsum plasters and ... Popovics [15] observes that this is true even for different types of ... proportions and curing ages of concrete samples are listed in table 1.

  19. On Structuring Subjective Judgements: Originality, Significance and Rigour in RAE2008

    Science.gov (United States)

    Johnston, Ron

    2008-01-01

    The 2008 United Kingdom Research Assessment Exercise will involve the evaluation of thousands of individual research outputs. The Funding Councils set three criteria for those evaluations--Originality, rigour and significance--and required each output to be placed into a fivefold categorisation of excellence, using absolute rather than relative…

  20. Significance of sterol structural specificity : desmosterol cannot replace cholesterol in lipid rafts

    NARCIS (Netherlands)

    Vainio, S.; Jansen, Maurice; Koivusalo, M.; Róg, T.; Karttunen, M.E.J.; Vattulainen, I.; Ikonen, E.

    2006-01-01

    Desmosterol is an immediate precursor of cholesterol in the Bloch pathway of sterol synthesis and an abundant membrane lipid in specific cell types. The significance of the difference between the two sterols, an additional double bond at position C24 in the tail of desmosterol, is not known. Here,

  1. Pathways to Structure-Property Relationships of Peptide-Materials Interfaces: Challenges in Predicting Molecular Structures.

    Science.gov (United States)

    Walsh, Tiffany R

    2017-07-18

    An in-depth appreciation of how to manipulate the molecular-level recognition between peptides and aqueous materials interfaces, including nanoparticles, will advance technologies based on self-organized metamaterials for photonics and plasmonics, biosensing, catalysis, energy generation and harvesting, and nanomedicine. Exploitation of the materials-selective binding of biomolecules is pivotal to success in these areas and may be particularly key to producing new hierarchically structured biobased materials. These applications could be accomplished by realizing preferential adsorption of a given biomolecule onto one materials composition over another, one surface facet over another, or one crystalline polymorph over another. Deeper knowledge of the aqueous abiotic-biotic interface, to establish clear structure-property relationships in these systems, is needed to meet this goal. In particular, a thorough structural characterization of the surface-adsorbed peptides is essential for establishing these relationships but can often be challenging to accomplish via experimental approaches alone. In addition to myriad existing challenges associated with determining the detailed molecular structure of any molecule adsorbed at an aqueous interface, experimental characterization of materials-binding peptides brings new, complex challenges because many materials-binding peptides are thought to be intrinsically disordered. This means that these peptides are not amenable to experimental techniques that rely on the presence of well-defined secondary structure in the peptide when in the adsorbed state. To address this challenge, and in partnership with experiment, molecular simulations at the atomistic level can bring complementary and critical insights into the origins of this abiotic/biotic recognition and suggest routes for manipulating this phenomenon to realize new types of hybrid materials. For the reasons outlined above, molecular simulation approaches also face

  2. Analysis of genetic structure and relationship among nine ...

    Indian Academy of Sciences (India)

    These results indicated that the clustering analysis using the Structure program might provide an ..... of the current genetic relations among the breeds, and con- tribute to ... sis of the genetic structure of the Canary goat populations using.

  3. The Phylogenetic Significance of Fruit Structural Variation in the Tribe Heteromorpheae (Apiaceae)

    International Nuclear Information System (INIS)

    Liu, M.; Lowry, P. P.; Magee, A. R.

    2016-01-01

    Fruit structure of Apiaceae was studied in 19 species representing the 10 genera of the tribe Heteromorpheae. Our results indicate this group has a woody habit, simple leaves, heteromorphic mericarps with lateral wings. fruits with bottle-shaped or bulging epidermal cells which have thickened and cutinized outer wall, regular vittae (one in furrow and two in commissure) and irregular vittae (short, dwarf, or branching and anatosmosing), and dispersed druse crystals. However, lateral winged mericarps, bottle-shaped epidermal cells, and branching and anatosmosing vittae are peculiar in the tribe Heteromorpheae of Apioideae sub family. Although many features share with other early-diverging groups of Apiaceae, including Annesorhiza clade, Saniculoideae sensu lato, Azorelloideae, Mackinlayoideae, as well as with Araliaceae. Our study shows that fruit anatomy can be used to define the tribe by molecular phylogenetic studies and support that Heteromorpheae are close to Annesorhiza clade and both are placed in the basal position of Apioideae. (author)

  4. [Evaluation of Significant Autobiographical Memories Scale: Design and structural validation at an exploratory level].

    Science.gov (United States)

    Lolich, María; Azzollini, Susana

    2016-11-01

    Personal memories are multimodal cognitive representations. Nowadays, psychometric instruments which aim to assess signifcant memories phenomenological features are scarce. Consequently, the Evaluation of Signifcant Autobiographical Memories Scale was constructed and structural validated at an exploratory level. A total of 404 individuals from Buenos Aires city (Argentina) participated in the research. Initially, an expert judgment and a pilot study administration were carried out. Next, a homogeneity and a principal components analysis were implemented. To assess the scale reliability, Cronbach's alphas coefficients were analyzed. The fnal version has 30 Likert response items gathered in 8 dimensions. Satisfactory psychometric proprieties were obtained - internal consistency of .892 and a total explained variance of 65.78%. The scale provides two main scores regarding the total quantity and intensity of the phenomenological components as well as a partial score per each dimension. It is stated that the test will prove to be useful in the research feld as well as in the clinical area.

  5. Central bank policy under significant balance-of-payment shocks and structural shifts

    Directory of Open Access Journals (Sweden)

    Andrey Sinyakov

    2016-09-01

    Full Text Available In this paper, we analyze a number of monetary and FX policy alternatives using the model of a small open oil-exporting economy hit by severe balance-of-payment shocks, such as those that simultaneously affected the Russian economy in 2014–2015. For our purposes, we modify Romer's (2013 IS-MP general equilibrium model by adding a structure similar to the Russian economy (tradables and oil vs. non-tradables. In the model, we consider an optimal policy mix that includes a floating exchange rate, FX liquidity provision by a central bank and temporary tightening of monetary policy. The flexible exchange rate works as a shock absorber, helping restore aggregate demand and domestic production. If inflation expectations are not anchored, contractionary monetary policy helps to stabilize them. Financial stability risks are addressed by lending FX liquidity to the banking sector.

  6. Significance of Nanoparticles and the Role of Amino Acids in Structuring Them-A Review.

    Science.gov (United States)

    Kulandaisamy, Arockia Jayalatha; Rayappan, John Bosco Balaguru

    2018-08-01

    Nanoparticles has occupied an eminent place in our tech-facilitated society. The processes involved in synthesizing nanoparticles are important not only to find their applications, but also to make them eco-friendly. Attempts are being made to replace the use of harmful surfactants/reagents by amino acids, in the due course of nanoparticle synthesis. Especially in synthesizing the multifunctional metal and metal oxide nanoparticles the use of amino acids as surfactant/as catalyst, helps to obtain required size and shape. Amino acids have the inherent property in directing and assembling the superstructures. They have the tendency to act as a capping agent and their presence during the synthesis processes alters the synthesized particles' morphology. Review has been made to study the role of amino acids like histidine, lysine, arginine in structuring ZnO, FeO, Au and Ag nanoparticles. The change in their morphology that resulted due to the addition of amino acids has been compared. It is important to understand the role of amino acids in synthesizing the nanoparticles, and so it is more important to understand the internal energy variation of the same. To achieve this, the interaction between the bio (amino acids) and non-bio (metal and metal oxide) nanoparticles are to be discussed both experimentally and theoretically. At times the theoretical characterization, especially at low dimensions, help us to understand inter-particle interaction and intra-particle interaction by determining their chemical potential and Lennard-Jones potential. This review has been concluded with a model to characterize the precursor solution (amino acids and inorganic materials) by considering the Equation of State for liquids, which could also be extended to determine the structure factor of nanoparticles.

  7. Quantitative structure-activity relationship of some 1-benzylbenzimidazole derivatives as antifungal agents

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2007-01-01

    Full Text Available In the present study, the antifungal activity of some 1-benzylbenzimidazole derivatives against yeast Saccharomyces cerevisiae was investigated. The tested benzimidazoles displayed in vitro antifungal activity and minimum inhibitory concentration (MIC was determined for all the compounds. Quantitative structure-activity relationship (QSAR has been used to study the relationships between the antifungal activity and lipophilicity parameter, logP, calculated by using CS Chem-Office Software version 7.0. The results are discussed on the basis of statistical data. The best QSAR model for prediction of antifungal activity of the investigated series of benzimidazoles was developed. High agreement between experimental and predicted inhibitory values was obtained. The results of this study indicate that the lipophilicity parameter has a significant effect on antifungal activity of this class of compounds, which simplify design of new biologically active molecules.

  8. Relationship between Temperament, Depression, Anxiety, and Hopelessness in Adolescents: A Structural Equation Model

    Directory of Open Access Journals (Sweden)

    Paolo Iliceto

    2011-01-01

    Full Text Available The purpose of this study was to test the validity of affective temperaments for predicting psychiatric morbidity and suicide risk, using a two-factor model to explain the relationships between temperament, anxiety, depression, and hopelessness. We investigated 210 high school students, 103 males and 107 females, 18-19 years old, who were administered self-report questionnaires to assess temperament (TEMPS-A, depression (BDI-II, anxiety (STAI and hopelessness (BHS. The final structural model had a good fit with the data, with two factors significantly correlated, the first labeled unstable cyclothymic temperament including Dysthymic/Cyclothymic/Anxious temperament, Irritable temperament and Depression, and the second labeled Demoralization including Anxiety (State/Trait and Hopelessness. Depression, anxiety and hopelessness are in a complex relationship partly mediated by temperament.

  9. Clinical Significance of Inflammatory Markers in Polycystic Ovary Syndrome: Their Relationship to Insulin Resistance and Body Mass Index

    Directory of Open Access Journals (Sweden)

    Nervana Samy

    2009-01-01

    Full Text Available Background: Women with polycystic ovary syndrome (PCOS have an increased prevalence of insulin resistance (IR and related disorders. Elevated serum levels of high sensitivity CRP (hs-CRP, interleukin-6 (IL-6 and tumor necrosis factor α (TNF-α reflect low-grade chronic inflammation and have been associated with several insulin-resistant states; they are useful cardiovascular risk markers. The objective of this study was to investigate whether soluble inflammatory markers are altered in PCOS focusing on its relationship with obesity and indexes of insulin resistance.

  10. Structural and reliability analysis of quality of relationship index in cancer patients.

    Science.gov (United States)

    Cousson-Gélie, Florence; de Chalvron, Stéphanie; Zozaya, Carole; Lafaye, Anaïs

    2013-01-01

    Among psychosocial factors affecting emotional adjustment and quality of life, social support is one of the most important and widely studied in cancer patients, but little is known about the perception of support in specific significant relationships in patients with cancer. This study examined the psychometric properties of the Quality of Relationship Inventory (QRI) by evaluating its factor structure and its convergent and discriminant validity in a sample of cancer patients. A total of 388 patients completed the QRI. Convergent validity was evaluated by testing the correlations between the QRI subscales and measures of general social support, anxiety and depression symptoms. Discriminant validity was examined by testing group comparison. The QRI's longitudinal invariance across time was also tested. Principal axis factor analysis with promax rotation identified three factors accounting for 42.99% of variance: perceived social support, depth, and interpersonal conflict. Estimates of reliability with McDonald's ω coefficient were satisfactory for all the QRI subscales (ω ranging from 0.75 - 0.85). Satisfaction from general social support was negatively correlated with the interpersonal conflict subscale and positively with the depth subscale. The interpersonal conflict and social support scales were correlated with depression and anxiety scores. We also found a relative stability of QRI subscales (measured 3 months after the first evaluation) and differences between partner status and gender groups. The Quality of Relationship Inventory is a valid tool for assessing the quality of social support in a particular relationship with cancer patients.

  11. Arterial relationships to the nerves and some rigid structures in the posterior cranial fossa.

    Science.gov (United States)

    Surchev, N

    2008-09-01

    The close relationships between the cranial nerves and the arterial vessels in the posterior cranial fossa are one of the predisposing factors for artery-nerve compression. The aim of this study was to examine the relationships of the vertebral and basilar arteries to some skull and dural structures and the nerves in the posterior cranial fossa. For this purpose, the skull bases and brains of 70 cadavers were studied. The topographic relationships of the vertebral and basilar arteries to the cranial nerves in the posterior cranial fossa were studied and the distances between the arteries and some osseous formations were measured. The most significant variations in arterial position were registered in the lower half of the basilar artery. Direct contact with an artery was established for the hypoglossal canal, jugular tubercle, and jugular foramen. The results reveal additional information about the relationships of the nerves and arteries to the skull and dural formations in the posterior cranial fossa. New quantitative information is given to illustrate them. The conditions for possible artery-nerve compression due to arterial dislocation are discussed and two groups (lines) of compression points are suggested. The medial line comprises of the brain stem points, usually the nerve root entry/exit zone. The lateral line includes the skull eminences, on which the nerves lie, or skull and dural foramina through which they exit the cranial cavity. (c) 2008 Wiley-Liss, Inc.

  12. Significance of foundation-soil separation in dynamic soil-structure interaction

    Science.gov (United States)

    Spyrakos, Constantine C.; Patel, P. N.

    1987-01-01

    THe dynamic response of flexible surface strip-foundations allowed to uplift is numerically obtained for externally applied forces of a transient time variation. The soil medium is represented by an isotropic, homogeneous and linear half-space. The soil is treated by a time domain boundary element method, while the flexible foundation is treated by the finite element method. It was concluded that intermediate relative stiffness leads to moderate deformations when uplift is permitted. Very flexible footings produce higher deformations in unilateral contact compared to bilateral contact, and thus should be considered in their design. Unilateral contact does not significantly increase deformations for stiff footings subjected to concentrated central loading. However, relatively large deformation differences occur when the loading is eccentric, necessitating consideration of uplift in their design.

  13. The relationship between quality management practices and organisational performance: A structural equation modelling approach

    Science.gov (United States)

    Jamaluddin, Z.; Razali, A. M.; Mustafa, Z.

    2015-02-01

    The purpose of this paper is to examine the relationship between the quality management practices (QMPs) and organisational performance for the manufacturing industry in Malaysia. In this study, a QMPs and organisational performance framework is developed according to a comprehensive literature review which cover aspects of hard and soft quality factors in manufacturing process environment. A total of 11 hypotheses have been put forward to test the relationship amongst the six constructs, which are management commitment, training, process management, quality tools, continuous improvement and organisational performance. The model is analysed using Structural Equation Modeling (SEM) with AMOS software version 18.0 using Maximum Likelihood (ML) estimation. A total of 480 questionnaires were distributed, and 210 questionnaires were valid for analysis. The results of the modeling analysis using ML estimation indicate that the fits statistics of QMPs and organisational performance model for manufacturing industry is admissible. From the results, it found that the management commitment have significant impact on the training and process management. Similarly, the training had significant effect to the quality tools, process management and continuous improvement. Furthermore, the quality tools have significant influence on the process management and continuous improvement. Likewise, the process management also has a significant impact to the continuous improvement. In addition the continuous improvement has significant influence the organisational performance. However, the results of the study also found that there is no significant relationship between management commitment and quality tools, and between the management commitment and continuous improvement. The results of the study can be used by managers to prioritize the implementation of QMPs. For instances, those practices that are found to have positive impact on organisational performance can be recommended to

  14. Relationship structure-antioxidant activity of hindered phenolic compounds

    Directory of Open Access Journals (Sweden)

    Weng, X. C.

    2014-12-01

    Full Text Available The relationship between the structure and the antioxidant activity of 21 hindered phenolic compounds was investigated by Rancimat and DPPH· tests. 3-tert-butyl-5-methylbenzene-1,2-diol is the strongest antioxidant in the Rancimat test but not in the DPPH· test because its two hydroxyl groups have very strong steric synergy. 2,6-Ditert-butyl-4-hydroxy-methylphenol exhibits a strong antioxidant activity as 2,6-ditertbutyl- 4-methoxyphenol does in lard. 2,6-Ditert-butyl-4- hydroxy-methylphenol also exhibits stronger activity than 2-tert-butyl-4- methoxyphenol. The methylene of 2,6-ditert-butyl-4-hydroxy-methylphenol can provide a hydrogen atom to active free radicals like a phenolic hydroxyl group does because it is greatly activated by both the aromatic ring and hydroxyl group. Five factors affect the antioxidant activities of the phenolic compounds: how stable the phenolic compound free radicals are after providing hydrogen atoms; how many hy drogen atoms each of the phenolic compounds can provide; how fast the phenolic compounds provide hydrogen atoms; how easily the phenolic compound free radicals can combine with more active free radicals, and whether or not a new antioxidant can form after the phenolic compound provides hydrogen atoms.La relación entre estructura y la actividad antioxidante de 21 compuestos fenólicos con impedimentos estéricos fue investigado mediante ensayos con Rancimat y DPPH·. El 3-terc-butil-5-metilbenceno-1,2-diol es el antioxidante más potente en los ensayos mediante Rancimat pero no mediante ensayos con DPPH·, porque sus dos grupos hidroxilo tienen una fuerte sinergia estérica. El 2,6-Di-terc-butil-4-hidroxi-metil-fenol mostró una actividad antioxidante tan fuerte como el 2,6-di-ter-butil-4-metoxifenol en ensayos con manteca de cerdo. El 2,6-di-terc-butil-4-hidroxi-metilfenol también mostró una actividad más fuerte que el 2-terc-butil-4-metoxifenol. El grupo metileno del 2,6-di-ter-butil-4-hidroxi

  15. Short interspersed elements (SINEs) of squamate reptiles (Squam1 and Squam2): structure and phylogenetic significance.

    Science.gov (United States)

    Grechko, Vernata V; Kosushkin, Sergei A; Borodulina, Olga R; Butaeva, Fatima G; Darevsky, Ilya S

    2011-05-15

    Short interspersed elements (SINEs) are important nuclear molecular markers of the evolution of many eukaryotes. However, the SINEs of squamate reptile genomes have been little studied. We first identified two families of SINEs, termed Squam1 and Squam2, in the DNA of meadow lizard Darevskia praticola (Lacertidae) by performing DNA hybridization and PCR. Later, the same families of retrotransposons were found using the same methods in members of another 25 lizard families (from Iguania, Scincomorpha, Gekkota, Varanoidea, and Diploglossa infraorders) and two snake families, but their abundances in these taxa varied greatly. Both SINEs were Squamata-specific and were absent from mammals, birds, crocodiles, turtles, amphibians, and fish. Squam1 possessed some characteristics common to tRNA-related SINEs from fish and mammals, while Squam2 belonged to the tRNA(Ala) group of SINEs and had a more unusual and divergent structure. Squam2-related sequences were found in several unannotated GenBank sequences of squamate reptiles. Squam1 abundance in the Polychrotidae, Agamidae, Leiolepididae, Chamaeleonidae, Scincidae, Lacertidae, Gekkonidae, Varanidae, Helodermatidae, and two snake families were 10(2) -10(4) times higher than those in other taxa (Corytophanidae, Iguanidae, Anguidae, Cordylidae, Gerrhosauridae, Pygopodidae, and Eublepharidae). A less dramatic degree of copy number variation was observed for Squam2 in different taxa. Several Squam1 copies from Lacertidae, Chamaeleonidae, Gekkonidae, Varanidae, and Colubridae were sequenced and found to have evident orthologous features, as well as taxa-specific autapomorphies. Squam1 from Lacertidae and Chamaeleonidae could be divided into several subgroups based on sequence differences. Possible applications of these SINEs as Squamata phylogeny markers are discussed. Copyright © 2010 Wiley-Liss, Inc., A Wiley Company.

  16. Using k-dependence causal forest to mine the most significant dependency relationships among clinical variables for thyroid disease diagnosis.

    Directory of Open Access Journals (Sweden)

    LiMin Wang

    Full Text Available Numerous data mining models have been proposed to construct computer-aided medical expert systems. Bayesian network classifiers (BNCs are more distinct and understandable than other models. To graphically describe the dependency relationships among clinical variables for thyroid disease diagnosis and ensure the rationality of the diagnosis results, the proposed k-dependence causal forest (KCF model generates a series of submodels in the framework of maximum spanning tree (MST and demonstrates stronger dependence representation. Friedman test on 12 UCI datasets shows that KCF has classification accuracy advantage over the other state-of-the-art BNCs, such as Naive Bayes, tree augmented Naive Bayes, and k-dependence Bayesian classifier. Our extensive experimental comparison on 4 medical datasets also proves the feasibility and effectiveness of KCF in terms of sensitivity and specificity.

  17. Quantitative structure-activation barrier relationship modeling for Diels-Alder ligations utilizing quantum chemical structural descriptors.

    Science.gov (United States)

    Nandi, Sisir; Monesi, Alessandro; Drgan, Viktor; Merzel, Franci; Novič, Marjana

    2013-10-30

    In the present study, we show the correlation of quantum chemical structural descriptors with the activation barriers of the Diels-Alder ligations. A set of 72 non-catalysed Diels-Alder reactions were subjected to quantitative structure-activation barrier relationship (QSABR) under the framework of theoretical quantum chemical descriptors calculated solely from the structures of diene and dienophile reactants. Experimental activation barrier data were obtained from literature. Descriptors were computed using Hartree-Fock theory using 6-31G(d) basis set as implemented in Gaussian 09 software. Variable selection and model development were carried out by stepwise multiple linear regression methodology. Predictive performance of the quantitative structure-activation barrier relationship (QSABR) model was assessed by training and test set concept and by calculating leave-one-out cross-validated Q2 and predictive R2 values. The QSABR model can explain and predict 86.5% and 80% of the variances, respectively, in the activation energy barrier training data. Alternatively, a neural network model based on back propagation of errors was developed to assess the nonlinearity of the sought correlations between theoretical descriptors and experimental reaction barriers. A reasonable predictability for the activation barrier of the test set reactions was obtained, which enabled an exploration and interpretation of the significant variables responsible for Diels-Alder interaction between dienes and dienophiles. Thus, studies in the direction of QSABR modelling that provide efficient and fast prediction of activation barriers of the Diels-Alder reactions turn out to be a meaningful alternative to transition state theory based computation.

  18. Interpretation of risk significance of passive component aging using probabilistic structural analysis

    International Nuclear Information System (INIS)

    Phillips, J.H.; Atwood, C.L.

    1993-01-01

    The probabilistic risk assessments (PRAs) being developed at most nuclear power plants to calculate the risk of core damage generally focus on the possible failure of active components. Except as initiating events, the possible failure of passive components is given little consideration. The NRC is sponsoring a project at INEL to investigate the risk significance of passive components as they age. For this project, we developed a technique to calculate the failure probability of passive components over time, and demonstrated the technique by applying it to a weld in the auxiliary feedwater (AFW) system. A decreasing yearly rupture rate for this weld was calculated instead of the increasing rupture rate trend one might expect. We attribute this result to infant mortality; that is, most of those initial flaws that will eventually lead to rupture will do so early in life. This means that although each weld in a population may be wearing out, the population as a whole can exhibit a decreasing rupture rate. This observation has implications for passive components in commercial nuclear plants and other facilities where aging is a concern. For the population of passive components that exhibit a decreasing failure rate, risk increase is not a concern. The next step of the work is to identify the attributes that contribute to this decreasing rate, and to determine any attributes that would contribute to an increasing failure rate and thus to an increased risk

  19. Relationships of quenching stresses to structural transformations in steel

    International Nuclear Information System (INIS)

    Loshkarev, V.E.

    1985-01-01

    Technique for accountancy of the effect of stresses on structural transformations in steel when solving problems of thermoplasticity is suggested. It is revealed on the basis of the conducted calculations that accountancy of interrelation of stressed and structural states of 20Kh2MF steel essentially affects forecasting of results of quenching

  20. Working relationships. A meta-view on structure and agency

    DEFF Research Database (Denmark)

    Weik, E.

    2006-01-01

    The article discusses the various contributions to the structure-agency debate with regard to their metaphysical assumptions concerning structure and agency. It argues that dualism theories, for all their positive contributions, cannot overcome certain problems due to their Cartesian heritage, wh...

  1. Structural relationships in rhombohedral perovskites with R-3C symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Bogush, A K; Pavlov, V I [AN Belorusskoj SSR, Minsk. Inst. Fiziki Tverdogo Tela i Poluprovodnikov

    1982-05-01

    In rhombohedral perovskites the structure parameters, e.g. the interaxial angle alpha/sub rh/ or the hexagonal lattice parameters a/sub H/ and c/sub H/ are completely determined by the tilt angle omega. The geometrical relations between these structural parameters and the tilt angle omega are reported.

  2. Computer-aided visualization of database structural relationships

    International Nuclear Information System (INIS)

    Cahn, D.F.

    1980-04-01

    Interactive computer graphic displays can be extremely useful in augmenting understandability of data structures. In complexly interrelated domains such as bibliographic thesauri and energy information systems, node and link displays represent one such tool. This paper presents examples of data structure representations found useful in these domains and discusses some of their generalizable components. 2 figures

  3. Materials science in microelectronics I the relationships between thin film processing and structure

    CERN Document Server

    Machlin, Eugene

    2005-01-01

    Thin films play a key role in the material science of microelectronics, and the subject matter of thin-films divides naturally into two headings: processing / structure relationship, and structure / properties relationship.The first volume of Materials Science in Microelectronics focuses on the first relationship - that between processing and the structure of the thin-film. The state of the thin film's surface during the period that one monolayer exists - before being buried in the next layer - determines the ultimate structure of the thin film, and thus its properties. This

  4. A validation of the Experiences in Close Relationships-Relationship Structures scale (ECR-RS) in adolescents

    DEFF Research Database (Denmark)

    Donbaek, Dagmar Feddern; Elklit, Ask

    2014-01-01

    structures in adults and, hence, moves beyond the traditional focus on romantic relationships. The present article explored the psychometric abilities of the ECR-RS across parental and best friend domains in a sample of 15 to 18-year-olds (n = 1999). Two oblique factors were revealed across domains...

  5. Quantitative structure-activity relationships of selective antagonists of glucagon receptor using QuaSAR descriptors.

    Science.gov (United States)

    Manoj Kumar, Palanivelu; Karthikeyan, Chandrabose; Hari Narayana Moorthy, Narayana Subbiah; Trivedi, Piyush

    2006-11-01

    In the present paper, quantitative structure activity relationship (QSAR) approach was applied to understand the affinity and selectivity of a novel series of triaryl imidazole derivatives towards glucagon receptor. Statistically significant and highly predictive QSARs were derived for glucagon receptor inhibition by triaryl imidazoles using QuaSAR descriptors of molecular operating environment (MOE) employing computer-assisted multiple regression procedure. The generated QSAR models revealed that factors related to hydrophobicity, molecular shape and geometry predominantly influences glucagon receptor binding affinity of the triaryl imidazoles indicating the relevance of shape specific steric interactions between the molecule and the receptor. Further, QSAR models formulated for selective inhibition of glucagon receptor over p38 mitogen activated protein (MAP) kinase of the compounds in the series highlights that the same structural features, which influence the glucagon receptor affinity, also contribute to their selective inhibition.

  6. Stimulation of Orobanche ramosa seed germination by fusicoccin derivatives: a structure-activity relationship study.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Fiore, Michele; Boari, Angela; Vurro, Maurizio

    2006-01-01

    A structure-activity relationship study was conducted assaying 25 natural analogues and derivatives of fusicoccin (FC), and cotylenol, the aglycone of cotylenins, for their ability to stimulate the seed germination of the parasitic species Orobanche ramosa. Some of the compounds tested proved to be highly active, being 8,9-isopropylidene of the corresponding FC aglycone and the dideacetyl derivative the most active FC derivatives. In both groups of glucosides and aglycones (including cotylenol), the most important structural feature to impart activity appears to be the presence of the primary hydroxy group at C-19. Furthermore, the functionalities and the conformation of the carbotricyclic ring proved to play a significant role. The dideacetyl derivative of FC, being easily and rapidly obtainable in high yield starting by FC, could be of interest for its practical application as a stimulant of Orobanche ramosa seed germination, inducing the "suicidal germination", an interesting approach for parasitic plant management.

  7. A Structural Model of Depression Based on Interpersonal Relationships: The Mediating Role of Coping Strategies and Loneliness.

    Science.gov (United States)

    Majd Ara, Elahe; Talepasand, Siavash; Rezaei, Ali Mohammad

    2017-06-01

    The present study was conducted with the aim of examining the structural model of interpersonal relationships and depression using coping strategies and loneliness as mediators. Using multistage random sampling, 301 high-school students were selected from Minudasht city, Iran. The participants were aksed to complete the Network of Relationships Inventory (NRI); the Ways of Coping Questionnaire (Lazarus and Folkman); the Children's Loneliness Scale (CLS); and the Depression, Anxiety, and Stress Scale (DASS-21). Structural equation modeling was used to examine the pattern of direct and indirect effects. Findings of the present study show that the data are well fitted to the model. The indirect effect of the positive quality of relationships was significant on depression through loneliness. Moreover, the indirect effects of the negative quality of relationships on depression through loneliness and through emotion-focused coping strategies were statistically significant. Although the effect of loneliness and emotion-focused coping strategies on depression was significant, problem-focused coping strategies did not have a significant effect on depression. Additionally, the findings suggested that the indirect effect through loneliness on depression was stronger compared with the indirect effect through emotion-focused coping strategies. The positive or negative quality of interpersonal relationships, loneliness, and emotion-focused coping strategy can significantly predict depression.

  8. The Relationship Between Organizational Structure and Organizational Control

    Science.gov (United States)

    Ouchi, William G.

    1977-01-01

    The results show that approximately 33 percent of the variance in control can be accounted for by structural characteristics, as well as by a characteristic of the environment--namely, the nature of the clientele served. (Author)

  9. Representation of molecular structure using quantum topology with inductive logic programming in structure-activity relationships.

    Science.gov (United States)

    Buttingsrud, Bård; Ryeng, Einar; King, Ross D; Alsberg, Bjørn K

    2006-06-01

    The requirement of aligning each individual molecule in a data set severely limits the type of molecules which can be analysed with traditional structure activity relationship (SAR) methods. A method which solves this problem by using relations between objects is inductive logic programming (ILP). Another advantage of this methodology is its ability to include background knowledge as 1st-order logic. However, previous molecular ILP representations have not been effective in describing the electronic structure of molecules. We present a more unified and comprehensive representation based on Richard Bader's quantum topological atoms in molecules (AIM) theory where critical points in the electron density are connected through a network. AIM theory provides a wealth of chemical information about individual atoms and their bond connections enabling a more flexible and chemically relevant representation. To obtain even more relevant rules with higher coverage, we apply manual postprocessing and interpretation of ILP rules. We have tested the usefulness of the new representation in SAR modelling on classifying compounds of low/high mutagenicity and on a set of factor Xa inhibitors of high and low affinity.

  10. Relationship between organizational structure and creativity in teaching hospitals.

    Science.gov (United States)

    Rezaee, Rita; Marhamati, Saadat; Nabeiei, Parisa; Marhamati, Raheleh

    2014-07-01

    Organization structure and manpower constitute two basic components of anorganization and both are necessary for stablishing an organization. The aim of this survey was to investigate the type of the organization structure (mechanic and organic) from viewpoint of senior and junior managers in Shiraz teaching hospitals and creativity in each of these two structures. In this cross-sectional and descriptive-analytic study, organization structure and organizational creation questionnaires were filled out by hospital managers. According to the statistical consultation and due to limited target population, the entire study population was considered as sample. Thus, the sample size in this study was 84 (12 hospitals and every hospital, n = 7). For data analysis, SPSS 14 was used and Spearman correlation coefficient and t-test were used. RESULTS showed that there is a negative association between centralization and complexity with organizational creation and its dimensions. Also there was a negative association between formalization and 4 organizational creation dimensions: reception change, accepting ambiguity, abet new view and less control outside (p=0.001). The results of this study showed that the creation in hospitals with organic structure is more than that in hospitals with mechanic structure.

  11. Integrative genomic approaches to dissect clinically-significant relationships between the VDR cistrome and gene expression in primary colon cancer.

    Science.gov (United States)

    Long, Mark D; Campbell, Moray J

    2017-10-01

    Recently, we undertook a pan-cancer analyses of the nuclear hormone receptor (NR) superfamily in The Cancer Genome Atlas (TCGA), and revealed that the vitamin D receptor (NR1I1/VDR) was commonly and significantly down-regulated specifically in colon adenocarcinoma cohort (COAD). To examine the consequence of down-regulated VDR expression we re-analyzed VDR chromatin immunoprecipitation sequencing (ChIP-Seq) data from LS180 colon cancer cells (GSE31939). This analysis identified 1809 loci that displayed significant (p.adjcolon tumor suppressor, Galactin 4) had significantly shorted disease free survival. These analyses suggest that reduced expression of VDR in colon cancer (but neither loss nor mutation) changes the actions of the VDR by both dampening the expression of tumor suppressors (e.g. LGALS4) whilst either stabilizing or not down-regulating expression of oncogenes (e.g. Carbonic Anhydrase 9 (CA9)). These integrative genomic approaches are relatively generic and applicable to the study of any transcription factor. Copyright © 2016. Published by Elsevier Ltd.

  12. A study on the relationship between organizational structure and organizational agility: A case study of insurance firm

    Directory of Open Access Journals (Sweden)

    Javad Sadeghi

    2012-09-01

    Full Text Available The primary aim of this survey is to study the relationship between organizational structure and organizational agility in an insurance company in Iran. The statistical population includes 300 employees and managers of the proposed insurance company across in Tehran province, Iran and a sample of 73 people are selected, randomly for the survey. Questionnaire is used as a major tool of data collection. Validity of the questionnaire is confirmed through content validity by professors and experts. Reliability of the questionnaire was calculated using Cronbach alpha. SPSS software is used for data analysis. Research findings illustrate there is a significant relationship between organizational agility and two dimensions of organizational structure, i.e. formalization and centralization. No significant relationship was observed between complexity and organizational agility.

  13. Social relationship difficulties in autism and reactive attachment disorder: Improving diagnostic validity through structured assessment.

    Science.gov (United States)

    Davidson, Claire; O'Hare, Anne; Mactaggart, Fiona; Green, Jonathan; Young, David; Gillberg, Christopher; Minnis, Helen

    2015-05-01

    Autism Spectrum Disorder (ASD) versus Reactive Attachment Disorder (RAD) is a common diagnostic challenge for clinicians due to overlapping difficulties with social relationships. RAD is associated with neglect or maltreatment whereas ASD is not: accurate differential diagnosis is therefore critical. Very little research has investigated the relationship between the two, and it is unknown if standardised measures are able to discriminate between ASD and RAD. The current study aimed to address these issues. Fifty eight children with ASD, and no history of maltreatment, were group matched on age with 67 children with RAD. Group profiles on multi-informant measures of RAD were investigated and group differences explored. Discriminant function analysis determined assessment features that best discriminated between the two groups. Although, according to parent report, children with ASD presented with significantly fewer indiscriminate friendliness behaviours compared to the RAD group (p<0.001), 36 children with ASD appeared to meet core RAD criteria. However, structured observation clearly demonstrated that features were indicative of ASD and not RAD for all but 1 of these 36 children. Children with RAD and children with ASD may demonstrate similar social relationship difficulties but there appears to be a difference in the social quality of the interactions between the groups. In most cases it was possible to differentiate between children with ASD and children with RAD via structured observation. Nevertheless, for a small proportion of children with ASD, particularly those whose difficulties may be more subtle, our current standardised measures, including structured observation, may not be effective in differentiating RAD from ASD. Copyright © 2015. Published by Elsevier Ltd.

  14. Significant relationships between a simple marker of redox balance and lifestyle behaviours; Relevance to the Framingham risk score.

    Directory of Open Access Journals (Sweden)

    Neda Seyedsadjadi

    Full Text Available Oxidative stress has been closely linked to the progressive cell damage associated with emerging non-communicable disease (NCDs. Early detection of these biochemical abnormalities before irreversible cell damage occurs may therefore be useful in identifying disease risk at an individual level. In order to test this hypothesis, this study assessed the relationship between a simple measure of redox status and lifestyle risk factors for NCDs, and the population-based risk score of Framingham. In a cross-sectional study design, 100 apparently healthy middle-aged males (n = 48 and females (n = 52 were asked to complete a comprehensive lifestyle assessment questionnaire, followed by body fat percentage and blood pressure measurements, and blood collection. The ratio of plasma total antioxidant capacity to hydroperoxide (TAC/HPX was used as an index of redox balance. One-way ANOVA and multiple linear regression analysis were performed to analyse the association between TAC/HPX, lifestyle components and other plasma biomarkers. The TAC/HPX ratio was higher in males compared to females (t96 = 2.34, P = 0.021. TAC/HPX was also lower in participants with poor sleep quality (t93 = 2.39, P = 0.019, with high sleep apnoea risk (t62.2 = 3.32, P = 0.002, with high caffeine (F(2, 93 = 3.97, P = 0.022 and red meat intake (F(2, 93 = 5.55, P = 0.005. These associations were independent of gender. Furthermore, the TAC/HPX ratio decreased with increasing body fat percentage (F(2, 95 = 4.74, P = 0.011 and depression score (t94 = 2.38, P = 0.019, though these associations were dependent on gender. Importantly, a negative association was observed between TAC/HPX levels and the Framingham risk score in both males (r(45 = -0.39, P = 0.008 and females (r(50 = -0.33, P = 0.019 that was independent of other Framingham risk score components. Findings from this study suggests that a relatively simple measure of redox balance such as the TAC/HPX ratio may be a sensitive

  15. [The significance of the relationship between external/internal locus of control and adolescent substance use in behavioral medicine].

    Science.gov (United States)

    Pikó, Bettina; Kovács, Eszter; Kriston, Pálma

    2011-02-27

    Prevention and treatment of the addictions are key public health priorities in modern society. In medical practice, in relation to the biochemical processes, mapping the addiction-prone personality traits, like external/internal locus of control are getting more and more attention. Individuals with high level on internal locus of control, for example, tend to take care of their health behavior; the lack of it, on the other hand, may worsen the effectiveness of stress release which may increase the likelihood of turning to substance use. The main goal of the present study was to investigate the relationship between adolescent substance use (both lifetime prevalence and the actual substance user status) and external/internal locus of control). The data collection of the questionnaire survey was going on among 656 high school students in Szeged (age range between 14-21 years, mean = 16.5 years, S.D. = 1.5 years of age, 49.1% of the sample was female). Associations between indicators of substance use (as dependent variables) and scale points of external/internal locus of control (as independent variables) were assessed using odds ratios calculated by logistic regression analyses, whereas gender was used as a controlling variable. Among boys, scale points of external, among girls, those of internal locus of control showed higher values. External locus of control increased, whereas internal locus of control decreased the risk of substance use, however, the relative role of external/internal locus of control was different according to the type of substance use and the prevalence values. In terms of smoking, lifetime prevalence, whereas in terms of marijuana use, the actual user status was influenced. In addition, while the latter one was also affected by gender, it did not play a role at all in the previous one. All these findings suggest that behavioral control may play a particularly important role in prevention of adolescent substance use. For developing this, methods

  16. Sigsearch: a new term for post hoc unplanned search for statistically significant relationships with the intent to create publishable findings.

    Science.gov (United States)

    Hashim, Muhammad Jawad

    2010-09-01

    Post-hoc secondary data analysis with no prespecified hypotheses has been discouraged by textbook authors and journal editors alike. Unfortunately no single term describes this phenomenon succinctly. I would like to coin the term "sigsearch" to define this practice and bring it within the teaching lexicon of statistics courses. Sigsearch would include any unplanned, post-hoc search for statistical significance using multiple comparisons of subgroups. It would also include data analysis with outcomes other than the prespecified primary outcome measure of a study as well as secondary data analyses of earlier research.

  17. Aromatic-Aromatic Interactions in Biological System: Structure Activity Relationships

    International Nuclear Information System (INIS)

    Rajagopal, Appavu; Deepa, Mohan; Govindaraju, Munisamy

    2016-01-01

    While, intramolecular hydrogen bonds have attracted the greatest attention in studies of peptide conformations, the recognition that several other weakly polar interactions may be important determinants of folded structure has been growing. Burley and Petsko provided a comprehensive overview of the importance of weakly polar interactions, in shaping protein structures. The interactions between aromatic rings, which are spatially approximate, have attracted special attention. A survey of the proximal aromatic residue pairs in proteins, allowed Burley and Petsko to suggest that, “phenyl ring centroids are separated by a preferential distance of between 4.5 and 7 Å, and dihedral angles approximately 90° are most common”

  18. Aromatic-Aromatic Interactions in Biological System: Structure Activity Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, Appavu; Deepa, Mohan [Molecular Biophysics Unit, Indian Institute of Sciences-Bangalore, Karnataka (India); Govindaraju, Munisamy [Bio-Spatial Technology Research Unit, Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu (India)

    2016-02-26

    While, intramolecular hydrogen bonds have attracted the greatest attention in studies of peptide conformations, the recognition that several other weakly polar interactions may be important determinants of folded structure has been growing. Burley and Petsko provided a comprehensive overview of the importance of weakly polar interactions, in shaping protein structures. The interactions between aromatic rings, which are spatially approximate, have attracted special attention. A survey of the proximal aromatic residue pairs in proteins, allowed Burley and Petsko to suggest that, “phenyl ring centroids are separated by a preferential distance of between 4.5 and 7 Å, and dihedral angles approximately 90° are most common”.

  19. Structure-activity relationship of CART peptide fragments

    Czech Academy of Sciences Publication Activity Database

    Maletínská, Lenka; Maixnerová, Jana; Hlaváček, Jan; Blokešová, Darja; Elbert, Tomáš; Šanda, Miloslav; Slaninová, Jiřina; Železná, Blanka

    2007-01-01

    Roč. 88, č. 4 (2007), s. 565 ISSN 0006-3525. [American Peptide Society Symposium /20./. 26.06.2007-30.06.2007, Montreal] Institutional research plan: CEZ:AV0Z40550506 Keywords : cocaine and amphetamine regulated transcript peptide * structure * activity Subject RIV: CE - Biochemistry

  20. The study of the relationship between pore structure and ...

    Indian Academy of Sciences (India)

    Administrator

    The pore structure was determined by the N2 adsorption/desorption method below. 73 K and calculated using the BJH model. TEM characterizations show that the pores are ... Mesoporous TiO2 was obtained by calcination of the gel at 500°C for 6 h in air to remove the surfactant species. The samples were designated as ...

  1. Structure-function relationships in sapwood water transport and storage.

    Science.gov (United States)

    Barbara L. Gartner; Frederick C. Meinzer

    2005-01-01

    Primary production by plants requires the loss of substantial quantities of water when the stomata are open for carbon assimilation. The delivery of that water to the leaves occurs through the xylem. The structure, condition, and quantity of the xylem control not only the transport efficiency but also the release of water from storage. For example, if there is high...

  2. Network-level structure-function relationships in human neocortex

    NARCIS (Netherlands)

    Miŝic, Bratislav; Betzel, Richard F.; De Reus, Marcel A.; Van Den Heuvel, Martijn P.; Berman, Marc G.; McIntosh, Anthony R.; Sporns, Olaf

    2016-01-01

    The dynamics of spontaneous fluctuations in neural activity are shaped by underlying patterns of anatomical connectivity. While numerous studies have demonstrated edge-wise correspondence between structural and functional connections, much less is known about how large-scale coherent functional

  3. The incidence of significant relationships between selected parameters of feet and parameters of trunk in children aged 4, 5 and 6 years

    Directory of Open Access Journals (Sweden)

    Mirosław Mrozkowiak

    2018-02-01

    2. Foot parameters revealed the most frequent significant relationship with trunk parameters in the sagittal and frontal planes. Trunk parameters with which foot parameters correlated most often included: asymmetry in the height of both scapulas with the right scapula up, inclination of thoracolumbar region and asymmetry in the height of waist triangles with the right triangle up.

  4. Molecular Descriptors Family on Structure Activity Relationships 1. Review of the Methodology

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2005-01-01

    Full Text Available This review cumulates the knowledge about the use of Molecular Descriptors Family usage on Structure Activity Relationships. The methodology is augmented through the general Structure Activity Relationships methodology. The obtained models in a series of five papers are quantitatively analyzed by comparing with previous reported results by using of the correlated correlations tests. The scores for a series of 13 data sets unpublished yet results are presented. Two unrestricted online access portals to the Molecular Descriptors Family Structure Activity Relationship models results are given.

  5. The relationship between occupational culture dimensions and reward preferences: A structural equation modelling approach

    Directory of Open Access Journals (Sweden)

    Mark Bussin

    2016-06-01

    Full Text Available Orientation: Reward has links to employee attraction and retention and as such has a role to play in managing talent. However, despite a range of research, there is still lack of clarity on employee preferences relating to reward. Research purpose: The purpose of the research was to recommend and appraise a theoretical model of the relationship between occupational culture dimensions and reward preferences of specific occupational groups in the South African context. Motivation for the study: The motivation for this study was to address the gap that exists with reward preferences and occupational culture with a view to identifying and gaining insight into individual preferences. Research design, approach and method: A structural equation modelling approach was adopted in exploring the proposed relationships. A South African Information, Communication, and Technology (ICT organisation served as the population, and a web-based survey assisted in gathering study data (n = 1362. Main findings: The findings provided support for the relationship between occupational culture dimensions and certain reward preferences. In particular, statistically significant results were obtained with the inclusion of the Environment, Team, and Time occupational culture dimensions as independent variables. Practical implications and value-add: The study provides workable input to organisations and reward professionals in the design of their reward strategies and programmes. Keywords: compensation; employee preferences; occupational culture; remuneration; reward preferences

  6. Sexual dimorphism of the incidence of significant relationships between selected foot parameters and trunk parameters in children aged 7 – 13 years

    Directory of Open Access Journals (Sweden)

    Mirosław Mrozkowiak

    2018-02-01

    2.                  The number of trunk parameters with which the features of feet correlated most significantly was found to be bigger in male subjects than in their female counterparts. The features in boys revealed a more frequent significant relationship whereas the differentiating features were observed only in the frontal plane.

  7. Connecting Structure-Property and Structure-Function Relationships across the Disciplines of Chemistry and Biology: Exploring Student Perceptions

    Science.gov (United States)

    Kohn, Kathryn P.; Underwood, Sonia M.; Cooper, Melanie M.

    2018-01-01

    While many university students take science courses in multiple disciplines, little is known about how they perceive common concepts from different disciplinary perspectives. Structure-property and structure-function relationships have long been considered important explanatory concepts in the disciplines of chemistry and biology, respectively.…

  8. The effect of leverage and/or influential on structure-activity relationships.

    Science.gov (United States)

    Bolboacă, Sorana D; Jäntschi, Lorentz

    2013-05-01

    In the spirit of reporting valid and reliable Quantitative Structure-Activity Relationship (QSAR) models, the aim of our research was to assess how the leverage (analysis with Hat matrix, h(i)) and the influential (analysis with Cook's distance, D(i)) of QSAR models may reflect the models reliability and their characteristics. The datasets included in this research were collected from previously published papers. Seven datasets which accomplished the imposed inclusion criteria were analyzed. Three models were obtained for each dataset (full-model, h(i)-model and D(i)-model) and several statistical validation criteria were applied to the models. In 5 out of 7 sets the correlation coefficient increased when compounds with either h(i) or D(i) higher than the threshold were removed. Withdrawn compounds varied from 2 to 4 for h(i)-models and from 1 to 13 for D(i)-models. Validation statistics showed that D(i)-models possess systematically better agreement than both full-models and h(i)-models. Removal of influential compounds from training set significantly improves the model and is recommended to be conducted in the process of quantitative structure-activity relationships developing. Cook's distance approach should be combined with hat matrix analysis in order to identify the compounds candidates for removal.

  9. Relationship of carotid arterial functional and structural changes to left atrial volume in untreated hypertension.

    Science.gov (United States)

    Jaroch, Joanna; Rzyczkowska, Barbara; Bociąga, Zbigniew; Vriz, Olga; Driussi, Caterina; Loboz-Rudnicka, Maria; Dudek, Krzysztof; Łoboz-Grudzień, Krystyna

    2016-04-01

    The contribution of arterial functional and structural changes to left ventricular (LV) diastolic dysfunction has been the area of recent research. There are some studies on the relationship between arterial stiffness (a.s.) and left atrial (LA) remodelling as a marker of diastolic burden. Little is known about the association of arterial structural changes and LA remodelling in hypertension (H). The aim of this study was to examine the relationship between carotid a.s. and intima-media thickness (IMT) and LA volume in subjects with H. The study included 245 previously untreated hypertensives (166 women and 79 men, mean age 53.7 ± 11.8 years). Each patient was subjected to echocardiography with measurement of LA volume, evaluation of left ventricular hypertrophy (LVH) and LV systolic/diastolic function indices, integrated assessment of carotid IMT and echo-tracking of a.s. and wave reflection parameters. Univariate regression analysis revealed significant correlations between indexed LA volume and selected clinical characteristics, echocardiographic indices of LVH and LV diastolic/systolic function and a.s./wave reflection parameters. The following parameters were identified as independent determinants of indexed LA volume on multivariate regression analysis: diastolic blood pressure (beta = -0.229, P arterial stiffness but not intima-media thickness and LA volume in patients with untreated hypertension.

  10. Relationship between mediation analysis and the structured life course approach

    Science.gov (United States)

    Howe, Laura D; Smith, Andrew D; Macdonald-Wallis, Corrie; Anderson, Emma L; Galobardes, Bruna; Lawlor, Debbie A; Ben-Shlomo, Yoav; Hardy, Rebecca; Cooper, Rachel; Tilling, Kate; Fraser, Abigail

    2016-01-01

    Abstract Many questions in life course epidemiology involve mediation and/or interaction because of the long latency period between exposures and outcomes. In this paper, we explore how mediation analysis (based on counterfactual theory and implemented using conventional regression approaches) links with a structured approach to selecting life course hypotheses. Using theory and simulated data, we show how the alternative life course hypotheses assessed in the structured life course approach correspond to different combinations of mediation and interaction parameters. For example, an early life critical period model corresponds to a direct effect of the early life exposure, but no indirect effect via the mediator and no interaction between the early life exposure and the mediator. We also compare these methods using an illustrative real-data example using data on parental occupational social class (early life exposure), own adult occupational social class (mediator) and physical capability (outcome). PMID:27681097

  11. Relationship between mediation analysis and the structured life course approach.

    Science.gov (United States)

    Howe, Laura D; Smith, Andrew D; Macdonald-Wallis, Corrie; Anderson, Emma L; Galobardes, Bruna; Lawlor, Debbie A; Ben-Shlomo, Yoav; Hardy, Rebecca; Cooper, Rachel; Tilling, Kate; Fraser, Abigail

    2016-08-01

    Many questions in life course epidemiology involve mediation and/or interaction because of the long latency period between exposures and outcomes. In this paper, we explore how mediation analysis (based on counterfactual theory and implemented using conventional regression approaches) links with a structured approach to selecting life course hypotheses. Using theory and simulated data, we show how the alternative life course hypotheses assessed in the structured life course approach correspond to different combinations of mediation and interaction parameters. For example, an early life critical period model corresponds to a direct effect of the early life exposure, but no indirect effect via the mediator and no interaction between the early life exposure and the mediator. We also compare these methods using an illustrative real-data example using data on parental occupational social class (early life exposure), own adult occupational social class (mediator) and physical capability (outcome). © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association.

  12. Structure function relationship of recombinant sRAGE

    OpenAIRE

    Premaratne, Dinamithra Gedara Sujeewani Rasika

    2017-01-01

    The receptor for advanced glycation end-products (RAGE) is a member of the immunoglobulin super family of cell surface receptors. It acts as the direct mediator of physiological and pathological responses such as inflammation, chemotaxis, neurite outgrowth, angiogenesis, apoptosis and proliferation. RAGE is known to bind with structurally and functionally diverse ligands, such as advanced glycation end-products (AGEs), high mobility group family proteins including HMGB-1/amphoterin, matrix pr...

  13. Children's representations of multiple family relationships: organizational structure and development in early childhood.

    Science.gov (United States)

    Schermerhorn, Alice C; Cummings, E Mark; Davies, Patrick T

    2008-02-01

    The authors examine mutual family influence processes at the level of children's representations of multiple family relationships, as well as the structure of those representations. From a community sample with 3 waves, each spaced 1 year apart, kindergarten-age children (105 boys and 127 girls) completed a story-stem completion task, tapping representations of multiple family relationships. Structural equation modeling with autoregressive controls indicated that representational processes involving different family relationships were interrelated over time, including links between children's representations of marital conflict and reactions to conflict, between representations of security about marital conflict and parent-child relationships, and between representations of security in father-child and mother-child relationships. Mixed support was found for notions of increasing stability in representations during this developmental period. Results are discussed in terms of notions of transactional family dynamics, including family-wide perspectives on mutual influence processes attributable to multiple family relationships.

  14. Relationship Structures and Semantic Type Assignments of the UMLS Enriched Semantic Network

    Science.gov (United States)

    Zhang, Li; Halper, Michael; Perl, Yehoshua; Geller, James; Cimino, James J.

    2005-01-01

    Objective: The Enriched Semantic Network (ESN) was introduced as an extension of the Unified Medical Language System (UMLS) Semantic Network (SN). Its multiple subsumption configuration and concomitant multiple inheritance make the ESN's relationship structures and semantic type assignments different from those of the SN. A technique for deriving the relationship structures of the ESN's semantic types and an automated technique for deriving the ESN's semantic type assignments from those of the SN are presented. Design: The technique to derive the ESN's relationship structures finds all newly inherited relationships in the ESN. All such relationships are audited for semantic validity, and the blocking mechanism is used to block invalid relationships. The mapping technique to derive the ESN's semantic type assignments uses current SN semantic type assignments and preserves nonredundant categorizations, while preventing new redundant categorizations. Results: Among the 426 newly inherited relationships, 326 are deemed valid. Seven blockings are applied to avoid inheritance of the 100 invalid relationships. Sixteen semantic types have different relationship structures in the ESN as compared to those in the SN. The mapping of semantic type assignments from the SN to the ESN avoids the generation of 26,950 redundant categorizations. The resulting ESN contains 138 semantic types, 149 IS-A links, 7,303 relationships, and 1,013,876 semantic type assignments. Conclusion: The ESN's multiple inheritance provides more complete relationship structures than in the SN. The ESN's semantic type assignments avoid the existing redundant categorizations appearing in the SN and prevent new ones that might arise due to multiple parents. Compared to the SN, the ESN provides a more accurate unifying semantic abstraction of the UMLS Metathesaurus. PMID:16049233

  15. Sustainable Corporate Social Media Marketing Based on Message Structural Features: Firm Size Plays a Significant Role as a Moderator

    Directory of Open Access Journals (Sweden)

    Moon Young Kang

    2018-04-01

    Full Text Available Social media has been receiving attention as a cost-effective tool to build corporate brand image and to enrich customer relationships. This phenomenon calls for more attention to developing a model that measures the impact of structural features, used in corporate social media messages. Based on communication science, this study proposes a model to measure the impact of three essential message structural features (interactivity, formality, and immediacy in corporate social media on customers’ purchase intentions, mediated by brand attitude and corporate trust. Especially, social media platforms are believed to provide a good marketing platform for small and medium enterprises (SMEs by providing access to huge audiences at a very low cost. The findings from this study based on a structural equation model suggest that brand attitude and corporate trust have larger impacts on purchase intention for SMEs than large firms. This implies that SMEs with little to no presence in the market should pay more attention to building corporate trust and brand attitude for their sustainable growth.

  16. TOXICOPHORES AND QUANTITATIVE STRUCTURE -TOXICITY RELATIONSHIPS FOR SOME ENVIRONMENTAL POLLUTANTS

    Directory of Open Access Journals (Sweden)

    N. N. Gorinchoy

    2008-06-01

    Full Text Available The electron-conformational (EC method is employed to reveal the toxicophore and to predict aquatic toxicity quantitatively using as a training set a series of 51 compounds that have aquatic toxicity to fish. By performing conformational analysis (optimization of geometries of the low-energy conformers by the PM3 method and electronic structure calculations (by ab initio method corrected within the SM54/PM3 solvatation model, the Electron-Conformational Matrix of Congruity (ECMC was constructed for each conformation of these compounds. The toxicophore defined as the EC sub-matrix of activity (ECSA, a sub-matrix with matrix elements common to all the active compounds under consideration within minimal tolerances, is determined by an iterative procedure of comparison of their ECMC’s, gradually minimizing the tolerances. Starting with only the four most toxic compounds, their ECSA (toxicophore was found to consists of a 4x4 matrix (four sites with certain electronic and topologic characteristics which was shown to be present in 17 most active compounds. A structure-toxicity correlation between three toxicophore parameters and the activities of these 17 compounds with R2=0.94 was found. It is shown that the same toxicophore with larger tolerances satisfies the compounds with les activity, thus explicitly demonstrating how the activity is controlled by the tolerances quantitatively and which atoms (sites are most flexible in this respect. This allows for getting slightly different toxicophores for different levels of activity. For some active compounds that have no toxicophore a bimolecular mechanism of activity is suggested. Distinguished from other QSAR methods, no arbitrary descriptors and no statistics are involved in this EC structure-activity investigation.

  17. Structure-activity relationships of strychnine analogues at glycine receptors

    DEFF Research Database (Denmark)

    Mohsen, A.M.Y.; Heller, Eberhard; Holzgrabe, Ulrike

    2014-01-01

    Nine strychnine derivatives including neostrychnine, strychnidine, isostrychnine, 21,22-dihydro-21-hydroxy-22-oxo-strychnine, and several hydrogenated analogs were synthesized, and their antagonistic activities at human α1 and α1β glycine receptors were evaluated. Isostrychnine has shown the best...... pharmacological profile exhibiting an IC50 value of 1.6 μM at α1 glycine receptors and 3.7-fold preference towards the α1 subtype. SAR Analysis indicates that the lactam moiety and the C(21)[DOUBLE BOND]C(22) bond in strychnine are essential structural features for its high antagonistic potency at glycine...

  18. The relationship between structural and functional connectivity: graph theoretical analysis of an EEG neural mass model

    NARCIS (Netherlands)

    Ponten, S.C.; Daffertshofer, A.; Hillebrand, A.; Stam, C.J.

    2010-01-01

    We investigated the relationship between structural network properties and both synchronization strength and functional characteristics in a combined neural mass and graph theoretical model of the electroencephalogram (EEG). Thirty-two neural mass models (NMMs), each representing the lump activity

  19. New insights about enzyme evolution from large scale studies of sequence and structure relationships

    OpenAIRE

    Babbitt, Patricia; Brown, SD; Babbitt, PC

    2014-01-01

    © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.Understanding how enzymes have evolved offers clues about their structure-function relationships and mechanisms. Here, we describe evolution of functionally diverse enzyme superfami

  20. Some Relationships Between Psychological Structure, Educational Beliefs, and Teaching Strategies in Three Types of Teacher Trainees.

    Science.gov (United States)

    Nier, Charles J.

    This study investigated systematic relationships among teacher personality types (Ambitious, Conscientious, and Indulgent), preservice educational beliefs, and intern classroom practices. The investigation traced the theoretical and empirical linkage from personality structure though educational ideology and finally to perceptions of teacher…

  1. 3D Printers Can Provide an Added Dimension for Teaching Structure-Energy Relationships

    Science.gov (United States)

    Blauch, David N.; Carroll, Felix A.

    2014-01-01

    A 3D printer is used to prepare a variety of models representing potential energy as a function of two geometric coordinates. These models facilitate the teaching of structure-energy relationships in molecular conformations and in chemical reactions.

  2. Gratitude, depression and PTSD: Assessment of structural relationships.

    Science.gov (United States)

    Van Dusen, John P; Tiamiyu, Mojisola F; Kashdan, Todd B; Elhai, Jon D

    2015-12-30

    Gratitude, the tendency to appreciate positive occurrences in one's life that can be partially attributed to another person, has been shown to be a robust predictor of greater well-being. Researchers have also found gratitude to be inversely related to several emotional disorders, including major depressive disorder (MDD) and posttraumatic stress disorder (PTSD). Both of these emotional disorders are highly comorbid and share dysphoric symptoms (e.g., restricted affect, detachment, anhedonia) that could account for deficits in the experience and expression of gratitude. We used confirmatory factor analysis to test the relationships between gratitude and the symptom factors of PTSD (using the DSM-5 model) and MDD in a sample of trauma-exposed college students (N=202). Results indicated that gratitude is more strongly related to PTSD's negative alterations in mood and cognition (NAMC) factor than to other PTSD factors. Implications of these findings for the study of gratitude and trauma are discussed, including whether gratitude and gratitude-based interventions might prove particularly suited to targeting depressive symptoms. Copyright © 2015. Published by Elsevier Ireland Ltd.

  3. GirlPOWER! Strengthening Mentoring Relationships through a Structured, Gender-Specific Program

    Science.gov (United States)

    Pryce, Julia M.; Silverthorn, Naida; Sanchez, Bernadette; DuBois, David L.

    2010-01-01

    The authors examine GirlPOWER! an innovative program that uses structure and group-based activities to enhance one-to-one mentoring relationships for young adolescent girls from the perspective of the focus, purpose, and authorship dimensions of mentoring relationships that Karcher and Nakkula described. The discussion draws on several sources of…

  4. Power in a startup's relationships with its established partners : Interactions between structural and behavioural power

    NARCIS (Netherlands)

    Oukes, Tamara; von Raesfeld Meijer, Ariane; Groen, Aard

    2017-01-01

    Power plays a key role in the relationships between startups and established organisations. Yet researchers have devoted little attention to the startup's perspective on power in such relationships. To study startups' view on power, a useful starting point is their structural power, but this also

  5. Structure-activity relationship of immunostimulatory effects of phthalates

    Directory of Open Access Journals (Sweden)

    Nielsen Gunnar D

    2008-10-01

    Full Text Available Abstract Background Some chemicals, including some phthalate plasticizers, have been shown to have an adjuvant effect in mice. However, an adjuvant effect, defined as an inherent ability to stimulate the humoral immune response, was only observed after exposure to a limited number of the phthalates. An adjuvant effect may be due to the structure or physicochemical characteristics of the molecule. The scope of this study was to investigate which molecular characteristics that determine the observed adjuvant effect of the most widely used phthalate plasticizer, the di-(2-ethylhexyl phthalate (DEHP, which is documented as having a strong adjuvant effect. To do so, a series of nine lipophilic compounds with structural and physicochemical relations to DEHP were investigated. Results Adjuvant effect of phthalates and related compounds were restricted to the IgG1 antibody formation. No effect was seen on IgE. It appears that lipophilicity plays a crucial role, but lipophilicity does not per se cause an adjuvant effect. In addition to lipophilicity, a phthalate must also possess specific stereochemical characteristics in order for it to have adjuvant effect. Conclusion The adjuvant effect of phthalates are highly influenced by both stereochemical and physico-chemical properties. This knowledge may be used in the rational development of plasticizers without adjuvant effect as well as in the design of new immunological adjuvants.

  6. Relationship between structure and reactivity in AOT inverse micelles

    International Nuclear Information System (INIS)

    Petit, Christophe

    1988-01-01

    As inverse micelles can be considered as chemical micro-reactors, the objective of this research thesis is to show that reaction rates can be modified, either by varying the size of micro-reactors, or by modifying the location of one of the reactants. After a brief overview of noticeable results obtained on AOT inverse micelles about the structure and reactivity, the author reports the study of structural modifications induced by an addition of small molecules or proteins. Two complementary models are proposed on this purpose: a geometrical model which reports the medium microscopic evolution and a kinetic model which could report the system microscopic evolution as well reactivity changes with respect to probe location. The next part reports the study of in situ synthesis of semi-conductor particles in AOT inverse micelles. The author then reports that a surprising aspect of macromolecule solubilization has been noticed: the solubilization of a polypeptide, gelatine, allows the whole system to be gelled whereas gelatine is essentially polar [fr

  7. Atomic structure-colour relationship in natural diamonds

    International Nuclear Information System (INIS)

    Godfrey, I S; Bangert, U

    2010-01-01

    Colour is a physical attribute that can be very difficult to characterise in diamond and consequently it receives regular attention from scientists working in the gem industry. In this work we compare natural brown (the most common colour) and colourless type IIa diamonds containing only trace quantities (< 1 at. ppm) of nitrogen. Numerous attempts have been made to trace the origin of brown tints in natural diamond, with the most likely culprits, i.e. dislocations and nitrogen impurities, ruled out through the application of various analytical techniques. Consequently more emphasis has recently been placed on the study of smaller defects in the diamond structure and their influence on colour. The focus of this research work is the analysis of vacancy defects having a size of the order of 1nm using aberration corrected scanning transmission electron microscopy (AC-STEM). The small electron probe size and depth of focus afforded by this technique allows such defect structures together with their position to be resolved far more readily than with conventional HR-TEM. Small-scale contrast variations are apparent in the lattice images of brown and not of colourless diamonds. These features have been compared to simulated phase contrast images of vacancy clusters in diamond. In addition, both experimental and simulated defocus series indicate that such features are not restricted to the surface of the specimen.

  8. Quantitative structure-activity relationships of salicylamide neuroleptic agents.

    Science.gov (United States)

    Gupta, S P; Saha, R N; Singh, P

    1990-05-01

    The in vitro antidopamine activity of substituted N-[(1-alkyl-2-pyrrolidinyl)methyl]-6-methoxysalicylamides was found to be well correlated with the hydrophobic and electronic nature of substituents at the 3-position, and with the steric nature of groups replacing the hydrogen atom of the salicyl hydroxy group. In contrast, only the hydrophobic and steric characteristics were found to be important in the in vivo activity of these neuroleptics. This difference suggests that different mechanisms are probably involved in their in vitro and in vivo actions, and that the relevant receptors are slightly different in structure. The in vitro results suggest that electron donation by the 3-substituent strengthens the formation of a hydrogen bond between the carbonyl group of the amide moiety and a hydrogen of the receptor.

  9. Institutional Structure and International Competitiveness Relationship in Developed Countries

    Directory of Open Access Journals (Sweden)

    Aynur Yıldırım

    2016-06-01

    Full Text Available This study analyzes the effects of institutional structure on the international competitiveness of developed countries econometrically by employing a “Panel Data Analysis” with a sample of 21 developed countries and 23 institutional variables for the period 2000-2011. The results of the analysis indicate that while judicial independence, protection of intellectual property rights, integrity of the juridical system, marginal tax, political freedoms, black market exchange rate, restrictions on foreign investment, private sector’s share in the banking system, hiring-minimum wage, and hiring-dismissal have a positive effect; the nature of legal arrangements, government spending, transfers and subsidies, civil liberties, tariffs, regulations regarding trade barriers, collective bargaining, and military tutelage have a negative effect on the international competitiveness of developed countries.

  10. Breast Milk Oligosaccharides: Structure-Function Relationships in the Neonate

    Science.gov (United States)

    Smilowitz, Jennifer T.; Lebrilla, Carlito B.; Mills, David A.; German, J. Bruce; Freeman, Samara L.

    2015-01-01

    In addition to providing complete postnatal nutrition, breast milk is a complex biofluid that delivers bioactive components for the growth and development of the intestinal and immune systems. Lactation is a unique opportunity to understand the role of diet in shaping the intestinal environment including the infant microbiome. Of considerable interest is the diversity and abundance of milk glycans that are energetically costly for the mammary gland to produce yet indigestible by infants. Milk glycans comprise free oligosaccharides, glycoproteins, glycopeptides, and glycolipids. Emerging technological advances are enabling more comprehensive, sensitive, and rapid analyses of these different classes of milk glycans. Understanding the impact of inter- and intraindividual glycan diversity on function is an important step toward interventions aimed at improving health and preventing disease. This review discusses the state of technology for glycan analysis and how specific structure-function knowledge is enhancing our understanding of early nutrition in the neonate. PMID:24850388

  11. Probing structure-antifouling activity relationships of polyacrylamides and polyacrylates.

    Science.gov (United States)

    Zhao, Chao; Zhao, Jun; Li, Xiaosi; Wu, Jiang; Chen, Shenfu; Chen, Qiang; Wang, Qiuming; Gong, Xiong; Li, Lingyan; Zheng, Jie

    2013-07-01

    We have synthesized two different polyacrylamide polymers with amide groups (polySBAA and polyHEAA) and two corresponding polyacrylate polymers without amide groups (polySBMA and polyHEA), with particular attention to the evaluation of the effect of amide group on the hydration and antifouling ability of these systems using both computational and experimental approaches. The influence of polymer architectures of brushes, hydrogels, and nanogels, prepared by different polymerization methods, on antifouling performance is also studied. SPR and ELISA data reveal that all polymers exhibit excellent antifouling ability to repel proteins from undiluted human blood serum/plasma, and such antifouling ability can be further enhanced by presenting amide groups in polySBAA and polyHEAA as compared to polySBMA and polyHEA. The antifouling performance is positively correlated with the hydration properties. Simulations confirm that four polymers indeed have different hydration characteristics, while all presenting a strong hydration overall. Integration of amide group with pendant hydroxyl or sulfobetaine group in polymer backbones is found to increase their surface hydration of polymer chains and thus to improve their antifouling ability. Importantly, we present a proof-of-concept experiment to synthesize polySBAA nanogels, which show a switchable property between antifouling and pH-responsive functions driven by acid-base conditions, while still maintaining high stability in undiluted fetal bovine serum and minimal toxicity to cultured cells. This work provides important structural insights into how very subtle structural changes in polymers can yield great improvement in biological activity, specifically the inclusion of amide group in polymer backbone/sidechain enables to obtain antifouling materials with better performance for biomedical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Understanding the mechanisms behind coking pressure: Relationship to pore structure

    Energy Technology Data Exchange (ETDEWEB)

    John J. Duffy; M. Castro Diaz; Colin E. Snape; Karen M. Steel; Merrick R. Mahoney [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2007-09-15

    Three low volatile coals A, B and C with oven wall pressures of 100 kPa, 60 kPa and 20 kPa respectively were investigated using high-temperature rheometry, {sup 1}H NMR, thermogravimetric analysis and SEM, with the primary aim to better understand the mechanisms behind the coking pressure phenomenon. Rheometer plate displacement measurements ({Delta}L) have shown differences in the expansion and contraction behaviour of the three coals, which seem to correlate with changes in rheological properties; while SEM images have shown that the expansion process coincides with development of pore structure. It is considered that the point of maximum plate height ({Delta}L{sub max}) prior to contraction may be indicative of a cell opening or pore network forming process, based on analogies with other foam systems. Such a process may be considered important for coking pressure since it provides a potential mechanism for volatile escape, relieving internal gas pressure and inducing charge contraction. For coal C, which has the highest fluidity {delta}L{sub max} occurs quite early in the softening process and consequently a large degree of contraction is observed; while for the lower fluidity coal B, the process is delayed since pore development and consequently wall thinning progress at a slower rate. When {Delta}L{sub max} is attained, a lower degree of contraction is observed because the event occurs closer to resolidification where the increasing viscosity/elasticity can stabilise the expanded pore structure. For coal A which is relatively high fluidity, but also high coking pressure, a greater degree of swelling is observed prior to cell rupture, which may be due to greater fluid elasticity during the expansion process. This excessive expansion is considered to be a potential reason for its high coking pressure. 58 refs., 15 figs., 1 tab.

  13. Significant population genetic structure detected in the rock bream Oplegnathus fasciatus (Temminck & Schlegel, 1844) inferred from fluorescent-AFLP analysis

    Science.gov (United States)

    Xiao, Yongshuang; Ma, Daoyuan; Xu, Shihong; Liu, Qinghua; Wang, Yanfeng; Xiao, Zhizhong; Li, Jun

    2016-05-01

    Oplegnathus fasciatus (rock bream) is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species along the coastal waters of China using fluorescent-amplified fragment length polymorphisms technology. Using 53 individuals from three populations and four pairs of selective primers, we amplified 1 264 bands, 98.73% of which were polymorphic. The Zhoushan population showed the highest Nei's genetic diversity and Shannon genetic diversity. The results of analysis of molecular variance (AMOVA) showed that 59.55% of genetic variation existed among populations and 40.45% occurred within populations, which indicated that a significant population genetic structure existed in the species. The pairwise fixation index F st ranged from 0.20 to 0.63 and were significant after sequential Bonferroni correction. The topology of an unweighted pair group method with arithmetic mean tree showed two significant genealogical branches corresponding to the sampling locations of North and South China. The AMOVA and STRUCTURE analyses suggested that the O. fasciatus populations examined should comprise two stocks.

  14. Structure-activity relationships of diverse xanthones against multidrug resistant human tumor cells.

    Science.gov (United States)

    Wang, Qiwen; Ma, Chenyao; Ma, Yun; Li, Xiang; Chen, Yong; Chen, Jianwei

    2017-02-01

    Thirteen xanthones were isolated naturally from the stem of Securidaca inappendiculata Hassk, and structure-activity relationships (SARs) of these compounds were comparatively predicted for their cytotoxic activity against three human multidrug resistant (MDR) cell lines MCF-7/ADR, SMMC-7721/Taxol, and A549/Taxol cells. The results showed that the selected xanthones exhibited different potent cytotoxic activity against the growth of different human tumor cell lines, and most of the xanthones exhibited selective cytotoxicity against SMMC-7721/Taxol cells. Furthermore, some tested xanthones showed stronger cytotoxicity than Cisplatin, which has been used in clinical application extensively. The SARs analysis revealed that the cytotoxic activities of diverse xanthones were affected mostly by the number and position of methoxyl and hydroxyl groups. Xanthones with more free hydroxyl and methoxyl groups increased the cytotoxic activity significantly, especially for those with the presence of C-3 hydroxyl and C-4 methoxyl groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Applications of genetic algorithms on the structure-activity relationship analysis of some cinnamamides.

    Science.gov (United States)

    Hou, T J; Wang, J M; Liao, N; Xu, X J

    1999-01-01

    Quantitative structure-activity relationships (QSARs) for 35 cinnamamides were studied. By using a genetic algorithm (GA), a group of multiple regression models with high fitness scores was generated. From the statistical analyses of the descriptors used in the evolution procedure, the principal features affecting the anticonvulsant activity were found. The significant descriptors include the partition coefficient, the molar refraction, the Hammet sigma constant of the substituents on the benzene ring, and the formation energy of the molecules. It could be found that the steric complementarity and the hydrophobic interaction between the inhibitors and the receptor were very important to the biological activity, while the contribution of the electronic effect was not so obvious. Moreover, by construction of the spline models for these four principal descriptors, the effective range for each descriptor was identified.

  16. Synthesis and structure-activity relationship exploration of some potent anti-cancer phenyl amidrazone derivatives.

    Science.gov (United States)

    Habashneh, Almeqdad Y; El-Abadelah, Mustafa M; Bardaweel, Sanaa K; Taha, Mutasem O

    2017-12-04

    Amidrazones have been reported to have significant anti-tumor properties against several cancer cell lines. The current project aims to profile the structure-anticancer activity relationship of phenyl-amidrazons. Fifteen phenyl-amidrazone-piperazine derivatives were prepared and tested against four cancer cell lines (leukemia, prostate, breast and colon cancers). Six compounds illustrated low micromolar anticancer IC50 values, while the remaining compounds were either inactive or of moderate potencies. All compounds were virtually nontoxic against normal fibroblast cells. Docking into the oncogenic kinase bcr/abl illustrated the critical importance of (i) p-halogen substituent on the ligand's phenyl ring and (ii) the presence of positive ionizable moiety at the ligand's piperazine fragment for anticancer activity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Structure-activity relationship of antiparasitic and cytotoxic indoloquinoline alkaloids, and their tricyclic and bicyclic analogues.

    Science.gov (United States)

    Van Baelen, Gitte; Hostyn, Steven; Dhooghe, Liene; Tapolcsányi, Pál; Mátyus, Péter; Lemière, Guy; Dommisse, Roger; Kaiser, Marcel; Brun, Reto; Cos, Paul; Maes, Louis; Hajós, György; Riedl, Zsuzsanna; Nagy, Ildikó; Maes, Bert U W; Pieters, Luc

    2009-10-15

    Based on the indoloquinoline alkaloids cryptolepine (1), neocryptolepine (2), isocryptolepine (3) and isoneocryptolepine (4), used as lead compounds for new antimalarial agents, a series of tricyclic and bicyclic analogues, including carbolines, azaindoles, pyrroloquinolines and pyrroloisoquinolines was synthesized and biologically evaluated. None of the bicyclic compounds was significantly active against the chloroquine-resistant strain Plasmodium falciparum K1, in contrast to the tricyclic derivatives. The tricyclic compound 2-methyl-2H-pyrido[3,4-b]indole (9), or 2-methyl-beta-carboline, showed the best in vitro activity, with an IC(50) value of 0.45 microM against P. falciparum K1, without apparent cytotoxicity against L6 cells (SI>1000). However, this compound was not active in the Plasmodium berghei mouse model. Structure-activity relationships are discussed and compared with related naturally occurring compounds.

  18. On-rate based optimization of structure-kinetic relationship--surfing the kinetic map.

    Science.gov (United States)

    Schoop, Andreas; Dey, Fabian

    2015-10-01

    In the lead discovery process residence time has become an important parameter for the identification and characterization of the most efficacious compounds in vivo. To enable the success of compound optimization by medicinal chemistry toward a desired residence time the understanding of structure-kinetic relationship (SKR) is essential. This article reviews various approaches to monitor SKR and suggests using the on-rate as the key monitoring parameter. The literature is reviewed and examples of compound series with low variability as well as with significant changes in on-rates are highlighted. Furthermore, findings of kinetic on-rate changes are presented and potential underlying rationales are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Molecular Descriptors Family on Structure Activity Relationships 3. Antituberculotic Activity of some Polyhydroxyxanthones

    Directory of Open Access Journals (Sweden)

    Sorana BOLBOACĂ

    2005-06-01

    Full Text Available The antituberculotic activity of some polyhydroxyxanthones was estimated using the Molecular Descriptors Family on Structure Activity Relationships methodology. From a total number of 298110 real and distinct calculated descriptors, 94843 were significantly different and entered into multiple linear regression analysis. The best performing bi-varied model was obtained by use of all polyhydroxyxanthones. The MDF SAR model was validated splitting the molecules into training and test sets. A correlated correlations analysis was applied in other to compare the MDF SAR models with the previous SAR model. The prediction ability of antituberculotic activity of polyhydroxyxanthones with MDF SAR methodology is sustained by three arguments: leave-one-out procedure, training vs. test procedure, and the correlated correlations analysis. Looking at the bi-varied MDF SAR model, we can conclude that the antituberculotic activity of polyhydroxyxanthones is almost of geometrical nature (99% and is strongly dependent on partial atomic charge and group electronegativity.

  20. Analysis Relationship Among Descriptor, References and Citation to Contruct the Inherent Structure of Document Collection

    International Nuclear Information System (INIS)

    Hasibuan, Zainal A.; Mustangimah

    2001-01-01

    There are many characteristics can be used to identify a document which cover characteristics of the documents, cited documents, and citing documents This research explored the inherent structure of a document collection as one of main components of information retrieval system. The characteristics examined are: descriptors, references (cited documents), and citations (citing documents). Three independent variables were studied: co-descriptor, bibliographic coupling, and co-citation. A test collection was constructed by searching on a single descriptor i nformation retrieval i n the CD-ROM version of Education Resource Information Clearinghouse (ERIC), covering the period 1981 through 1985. Descriptors were extracted from ERIC; cited and citing documents associated with the test collection were derived from Social Sciences Citation Index (SSCI), covering the period 1981 through 1990. Three hypothesis were tested in this study, that are: (1) the higher the frequency of co-descriptors between documents, the higher the frequencies of their bibliographic coupling and co-citation; (2) the higher the frequency of bibliographic coupling between documents, the higher the frequencies of their co-citation and co-descriptors; and (3) the higher the frequency of co-citation between documents, the higher the frequencies of their co-descriptors and bibliographic coupling. The results showed that all of three hypothesis are supported statistically and there is a significant linear relationship among the observed variables. It is mean that there is a significant relationship among descriptors, references, and citation, so that it can be used to construct the inherent structure of document collection in order to improve information retrieval system performance

  1. Impact velocity vs. target hardness relationships for equivalent response of cask structures

    International Nuclear Information System (INIS)

    Chen, T.F.; Chen, J.C.; Witte, M.C.; Fischer, L.E.

    1993-01-01

    In this paper, impact velocity vs. target hardness relationships for cask structures are reviewed. The relationships are based on equivalent cask responses in terms of equal deceleration or similar cask damages. By examining several past cask or container tests as well as some analytical results, some conclusions can be drawn about the relationship between target hardness and equivalent impact velocities. This relationship clearly shows that the cask response to impact is cask-dependent and that the rigid sphere impact model results in an unconservative estimate of equivalent velocity

  2. Noncoded amino acids in protein engineering: Structure-activity relationship studies of hirudin-thrombin interaction.

    Science.gov (United States)

    De Filippis, Vincenzo; Acquasaliente, Laura; Pontarollo, Giulia; Peterle, Daniele

    2018-01-01

    The advent of recombinant DNA technology allowed to site-specifically insert, delete, or mutate almost any amino acid in a given protein, significantly improving our knowledge of protein structure, stability, and function. Nevertheless, a quantitative description of the physical and chemical basis that makes a polypeptide chain to efficiently fold into a stable and functionally active conformation is still elusive. This mainly originates from the fact that nature combined, in a yet unknown manner, different properties (i.e., hydrophobicity, conformational propensity, polarizability, and hydrogen bonding capability) into the 20 standard natural amino acids, thus making difficult, if not impossible, to univocally relate the change in protein stability or function to the alteration of physicochemical properties caused by amino acid exchange(s). In this view, incorporation of noncoded amino acids with tailored side chains, allowing to finely tune the structure at a protein site, would facilitate to dissect the effects of a given mutation in terms of one or a few physicochemical properties, thus much expanding the scope of physical organic chemistry in the study of proteins. In this review, relevant applications from our laboratory will be presented on the use of noncoded amino acids in structure-activity relationships studies of hirudin binding to thrombin. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

  3. Synthesis and anticancer structure activity relationship investigation of cationic anthraquinone analogs.

    Science.gov (United States)

    Shrestha, Jaya P; Fosso, Marina Y; Bearss, Jeremiah; Chang, Cheng-Wei Tom

    2014-04-22

    We have synthesized a series of novel 4,9-dioxo-4,9-dihydro-1H-naphtho[2,3-d][1,2,3]triazol-3-ium salts, which can be viewed as analogs of cationic anthraquinones. Unlike the similar analogs that we have reported previously, these compounds show relatively weak antibacterial activities but exert strong anticancer activities (low μM to nM GI50), in particular, against melanoma, colon cancer, non-small cell lung cancer and central nervous system (CNS) cancer. These compounds are structurally different from their predecessors by having the aromatic group, instead of alkyl chains, directly attached to the cationic anthraquinone scaffold. Further investigation in the structure-activity relationship (SAR) reveals the significant role of electron donating substituents on the aromatic ring in enhancing the anticancer activities via resonance effect. Steric hindrance of these groups is disadvantageous but is less influential than the resonance effect. The difference in the attached groups at N-1 position of the cationic anthraquinone analog is the main structural factor for the switching of biological activity from antibacterial to anticancer. The discovery of these compounds may lead to the development of novel cancer chemotherapeutics. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Structure/Psychophysical Relationships in X-Linked Retinoschisis.

    Science.gov (United States)

    Bennett, Lea D; Wang, Yi-Zhong; Klein, Martin; Pennesi, Mark E; Jayasundera, Thiran; Birch, David G

    2016-02-01

    To compare structural properties from spectral-domain optical coherence tomography (SDOCT) and psychophysical measures from a subset of patients enrolled in a larger multicenter natural history study of X-linked retinoschisis (XLRS). A subset of males (n = 24) participating in a larger natural history study of XLRS underwent high-resolution SDOCT. Total retina (TR) thickness and outer segment (OS) thickness were measured manually. Shape discrimination hyperacuity (SDH) and contour integration perimetry (CIP) were performed on an iPad with the myVisionTrack application. Sensitivity was measured with fundus-guided perimetry (4-2 threshold testing strategy; 10-2 grid, spot size 3, 68 points). Correlation was determined with Pearson's r correlation. Values are presented as the mean ± SD. Mean macular OS thickness was less in XLRS patients (17.2 ± 8.1 μm) than in controls (37.1 ± 5.7 μm; P weak correlation with TR thickness (R(2) = 0.22, P = 0.0158). The XLRS subjects had a logMAR best corrected visual acuity (BCVA) of 0.5 ± 0.3 that was associated with OS (R(2) = 0.79, P < 0.0001) but not TR thickness (R(2) = 0.01, P = 0.6166). Shape DH and CIP inner ring correlated with OS (R(2) = 0.33, P = 0.0085 and R(2) = 0.47, P = 0.0001, respectively) but not TR thickness (R(2) = 0.0004, P = 0.93; R(2) = 0.0043, P = 0.75, respectively). When considered from a single visit, OS thickness within the macula is more closely associated with macular function than TR thickness within the macula in patients with XLRS.

  5. Quantitative structure-retention relationship studies with immobilized artificial membrane chromatography II: partial least squares regression.

    Science.gov (United States)

    Li, Jie; Sun, Jin; He, Zhonggui

    2007-01-26

    We aimed to establish quantitative structure-retention relationship (QSRR) with immobilized artificial membrane (IAM) chromatography using easily understood and obtained physicochemical molecular descriptors and to elucidate which descriptors are critical to affect the interaction process between solutes and immobilized phospholipid membranes. The retention indices (logk(IAM)) of 55 structurally diverse drugs were determined on an immobilized artificial membrane column (IAM.PC.DD2) directly or obtained by extrapolation method for highly hydrophobic compounds. Ten simple physicochemical property descriptors (clogP, rings, rotatory bond, hydro-bond counting, etc.) of these drugs were collected and used to establish QSRR and predict the retention data by partial least squares regression (PLSR). Five descriptors, clogP, rotatory bond (RotB), rings, molecular weight (MW) and total surface area (TSA), were reserved by using the Variable Importance for Projection (VIP) values as criterion to build the final PLSR model. An external test set was employed to verify the QSRR based on the training set with the five variables, and QSRR by PLSR exhibited a satisfying predictive ability with R(p)=0.902 and RMSE(p)=0.400. Comparison of coefficients of centered and scaled variables by PLSR demonstrated that, for the descriptors studied, clogP and TSA have the most significant positive effect but the rotatable bond has significant negative effect on drug IAM chromatographic retention.

  6. The Relationship between Bureaucratic School Structures and Teacher Self-Efficacy

    Science.gov (United States)

    Kilinç, Ali Çagatay; Kosar, Serkan; Er, Emre; Ögdem, Zeki

    2016-01-01

    The purpose of this study was to examine the relationship between bureaucratic school structures and teachers' self-efficacy. Participants included 252 teachers from 15 primary schools in Ankara, Turkey. Mean, standard deviation, correlation, and regression analyses were conducted. Results indicated that bureaucratic school structures and teacher…

  7. Spiders in Motion: Demonstrating Adaptation, Structure-Function Relationships, and Trade-Offs in Invertebrates

    Science.gov (United States)

    Bowlin, Melissa S.; McLeer, Dorothy F.; Danielson-Francois, Anne M.

    2014-01-01

    Evolutionary history and structural considerations constrain all aspects of animal physiology. Constraints on invertebrate locomotion are especially straightforward for students to observe and understand. In this exercise, students use spiders to investigate the concepts of adaptation, structure-function relationships, and trade-offs. Students…

  8. Quantitative structure-activity relationships for green algae growth inhibition by polymer particles.

    NARCIS (Netherlands)

    Nolte, Tom M; Peijnenburg, Willie J G M; Hendriks, A Jan; van de Meent, Dik

    After use and disposal of chemical products, many types of polymer particles end up in the aquatic environment with potential toxic effects to primary producers like green algae. In this study, we have developed Quantitative Structure-Activity Relationships (QSARs) for a set of highly structural

  9. Examining Relationships among Enabling School Structures, Academic Optimism and Organizational Citizenship Behaviors

    Science.gov (United States)

    Messick, Penelope Pope

    2012-01-01

    This study examined the relationships among enabling school structures, academic optimism, and organizational citizenship behaviors. Additionally, it sought to determine if academic optimism served as a mediator between enabling school structures and organizational citizenship behaviors. Three existing survey instruments, previously tested for…

  10. Relationships between avian richness and landscape structure at multiple scales using multiple landscapes

    Science.gov (United States)

    Michael S. Mitchell; Scott H. Rutzmoser; T. Bently Wigley; Craig Loehle; John A. Gerwin; Patrick D. Keyser; Richard A. Lancia; Roger W. Perry; Christopher L. Reynolds; Ronald E. Thill; Robert Weih; Don White; Petra Bohall Wood

    2006-01-01

    Little is known about factors that structure biodiversity on landscape scales, yet current land management protocols, such as forest certification programs, place an increasing emphasis on managing for sustainable biodiversity at landscape scales. We used a replicated landscape study to evaluate relationships between forest structure and avian diversity at both stand...

  11. Quantitative structure activity relationship (QSAR) of piperine analogs for bacterial NorA efflux pump inhibitors.

    Science.gov (United States)

    Nargotra, Amit; Sharma, Sujata; Koul, Jawahir Lal; Sangwan, Pyare Lal; Khan, Inshad Ali; Kumar, Ashwani; Taneja, Subhash Chander; Koul, Surrinder

    2009-10-01

    Quantitative structure activity relationship (QSAR) analysis of piperine analogs as inhibitors of efflux pump NorA from Staphylococcus aureus has been performed in order to obtain a highly accurate model enabling prediction of inhibition of S. aureus NorA of new chemical entities from natural sources as well as synthetic ones. Algorithm based on genetic function approximation method of variable selection in Cerius2 was used to generate the model. Among several types of descriptors viz., topological, spatial, thermodynamic, information content and E-state indices that were considered in generating the QSAR model, three descriptors such as partial negative surface area of the compounds, area of the molecular shadow in the XZ plane and heat of formation of the molecules resulted in a statistically significant model with r(2)=0.962 and cross-validation parameter q(2)=0.917. The validation of the QSAR models was done by cross-validation, leave-25%-out and external test set prediction. The theoretical approach indicates that the increase in the exposed partial negative surface area increases the inhibitory activity of the compound against NorA whereas the area of the molecular shadow in the XZ plane is inversely proportional to the inhibitory activity. This model also explains the relationship of the heat of formation of the compound with the inhibitory activity. The model is not only able to predict the activity of new compounds but also explains the important regions in the molecules in quantitative manner.

  12. Significance of uncertainties derived from settling tank model structure and parameters on predicting WWTP performance - A global sensitivity analysis study

    DEFF Research Database (Denmark)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen

    2011-01-01

    Uncertainty derived from one of the process models – such as one-dimensional secondary settling tank (SST) models – can impact the output of the other process models, e.g., biokinetic (ASM1), as well as the integrated wastewater treatment plant (WWTP) models. The model structure and parameter...... and from the last aerobic bioreactor upstream to the SST (Garrett/hydraulic method). For model structure uncertainty, two one-dimensional secondary settling tank (1-D SST) models are assessed, including a first-order model (the widely used Takács-model), in which the feasibility of using measured...... uncertainty of settler models can therefore propagate, and add to the uncertainties in prediction of any plant performance criteria. Here we present an assessment of the relative significance of secondary settling model performance in WWTP simulations. We perform a global sensitivity analysis (GSA) based...

  13. Relationships between hormones and aggressive behavior in green anole lizards: an analysis using structural equation modeling.

    Science.gov (United States)

    Yang, Eun-Jin; Wilczynski, Walter

    2002-09-01

    We investigated the relationship between aggressive behavior and circulating androgens in the context of agonistic social interaction and examined the effect of this interaction on the androgen-aggression relationship in response to a subsequent social challenge in male Anolis carolinensis lizards. Individuals comprising an aggressive encounter group were exposed to an aggressive conspecific male for 10 min per day during a 5-day encounter period, while controls were exposed to a neutral stimulus for the same period. On the sixth day, their responses to an intruder test were observed. At intervals, individuals were sacrificed to monitor plasma androgen levels. Structural equation modeling (SEM) was used to test three a priori interaction models of the relationship between social stimulus, aggressive behavior, and androgen. Model 1 posits that exposure to a social stimulus influences androgen and aggressive behavior independently. In Model 2, a social stimulus triggers aggressive behavior, which in turn increases circulating levels of androgen. In Model 3, exposure to a social stimulus influences circulating androgen levels, which in turn triggers aggressive behavior. During the 5 days of the encounter period, circulating testosterone (T) levels of the aggressive encounter group followed the same pattern as their aggressive behavioral responses, while the control group did not show significant changes in their aggressive behavior or T level. Our SEM results supported Model 2. A means analysis showed that during the intruder test, animals with 5 days of aggressive encounters showed more aggressive responses than did control animals, while their circulating androgen levels did not differ. This further supports Model 2, suggesting that an animal's own aggressive behavior may trigger increases in levels of plasma androgen. Copyright 2002 Elsevier Science (USA)

  14. Relationship between Structural and Stress Relaxation in a Block-Copolymer Melt

    International Nuclear Information System (INIS)

    Patel, Amish J.; Narayanan, Suresh; Sandy, Alec; Mochrie, Simon G. J.; Garetz, Bruce A.; Watanabe, Hiroshi; Balsara, Nitash P.

    2006-01-01

    The relationship between structural relaxation on molecular length scales and macroscopic stress relaxation was explored in a disordered block-copolymer melt. Experiments show that the structural relaxation time, measured by x-ray photon correlation spectroscopy is larger than the terminal stress relaxation time, measured by rheology, by factors as large as 100. We demonstrate that the structural relaxation data are dominated by the diffusion of intact micelles while the stress relaxation data are dominated by contributions due to disordered concentration fluctuations

  15. Quantitative Structure – Antioxidant Activity Relationships of Flavonoid Compounds

    Directory of Open Access Journals (Sweden)

    Károly Héberger

    2004-12-01

    Full Text Available A quantitative structure – antioxidant activity relationship (QSAR study of 36 flavonoids was performed using the partial least squares projection of latent structures (PLS method. The chemical structures of the flavonoids have been characterized by constitutional descriptors, two-dimensional topological and connectivity indices. Our PLS model gave a proper description and a suitable prediction of the antioxidant activities of a diverse set of flavonoids having clustering tendency.

  16. Microsatellite data suggest significant population structure and differentiation within the malaria vector Anopheles darlingi in Central and South America

    Directory of Open Access Journals (Sweden)

    Achee Nicole L

    2008-03-01

    Full Text Available Abstract Background Anopheles darlingi is the most important malaria vector in the Neotropics. An understanding of A. darlingi's population structure and contemporary gene flow patterns is necessary if vector populations are to be successfully controlled. We assessed population genetic structure and levels of differentiation based on 1,376 samples from 31 localities throughout the Peruvian and Brazilian Amazon and Central America using 5–8 microsatellite loci. Results We found high levels of polymorphism for all of the Amazonian populations (mean RS = 7.62, mean HO = 0.742, and low levels for the Belize and Guatemalan populations (mean RS = 4.3, mean HO = 0.457. The Bayesian clustering analysis revealed five population clusters: northeastern Amazonian Brazil, southeastern and central Amazonian Brazil, western and central Amazonian Brazil, Peruvian Amazon, and the Central American populations. Within Central America there was low non-significant differentiation, except for between the populations separated by the Maya Mountains. Within Amazonia there was a moderate level of significant differentiation attributed to isolation by distance. Within Peru there was no significant population structure and low differentiation, and some evidence of a population expansion. The pairwise estimates of genetic differentiation between Central America and Amazonian populations were all very high and highly significant (FST = 0.1859 – 0.3901, P DA and FST distance-based trees illustrated the main division to be between Central America and Amazonia. Conclusion We detected a large amount of population structure in Amazonia, with three population clusters within Brazil and one including the Peru populations. The considerable differences in Ne among the populations may have contributed to the observed genetic differentiation. All of the data suggest that the primary division within A. darlingi corresponds to two white gene genotypes between Amazonia (genotype 1

  17. Sexual dimorphism of the incidence of significant relationships between selected parameters of feet and characteristics of trunk in adolescents aged 14 – 18 years

    Directory of Open Access Journals (Sweden)

    Mirosław Mrozkowiak

    2018-03-01

    Full Text Available Summary Introduction. Symmetry, asymmetry, mutual relationships and concomitance have become a subject of interest of numerous researchers. The analysis of the findings obtained in the own study conducted among adolescents aged 14-18 years revealed an incidental nature and randomness of the distribution of significant correlations in each age and gender range, which made it impossible to show any regularities or dependencies between the measured parameters. Material and method. The examinations carried out in the group of teenagers aged 14 to 18 years recorded 2,343 observations, including 1,148 girls and 1,195 boys, concerning the size of 89 parameters describing trunk and feet. The station for an assessment of selected features using the photogrammetric method consisted of a computer, a card, software, a display monitor, a printer and a projection-reception device with a camera.     Findings 1. The number of feet parameters revealing significant relationships with trunk parameters which differentiated the female gender from the male one was greater; likewise, the features in women revealed a more frequent relationship. Additionally, female sex was differentiated by morphological traits, the abnormal positioning of toes and the longitudinal arch of feet. 2. The number of trunk parameters correlating with foot parameters was observed to be bigger in the female gender than in the male one. The parameters in female subjects showed more relationships and the parameters which differentiated female sex included the frontal plane and the sagittal plane to a lesser extent, whereas male gender was characterized by the sagittal plane.

  18. Significantly Elevated Dielectric and Energy Storage Traits in Boron Nitride Filled Polymer Nano-composites with Topological Structure

    Science.gov (United States)

    Feng, Yefeng; Zhang, Jianxiong; Hu, Jianbing; Li, Shichun; Peng, Cheng

    2018-03-01

    Interface induced polarization has a prominent influence on dielectric properties of 0-3 type polymer based composites containing Si-based semi-conductors. The disadvantages of composites were higher dielectric loss, lower breakdown strength and energy storage density, although higher permittivity was achieved. In this work, dielectric, conductive, breakdown and energy storage properties of four nano-composites have been researched. Based on the cooperation of fluoropolymer/alpha-SiC layer and fluoropolymer/hexagonal-BN layer, it was confirmed constructing the heterogeneous layer-by-layer composite structure rather than homogeneous mono-layer structure could significantly reduce dielectric loss, promote breakdown strength and increase energy storage density. The former worked for a larger dielectric response and the latter layer acted as a robust barrier of charge carrier transfer. The best nano-composite could possess a permittivity of 43@100 Hz ( 3.3 times of polymer), loss of 0.07@100 Hz ( 37% of polymer), discharged energy density of 2.23 J/cm3@249 kV/cm ( 10 times of polymer) and discharged energy efficiency of 54%@249 kV/cm ( 5 times of polymer). This work might enlighten a facile route to achieve the promising high energy storage composite dielectrics by constructing the layer-by-layer topological structure.

  19. Porphyrins from Messel oil shale (Eocene, Germany): Structure elucidation, geochemical and biological significance, and distribution as a function of depth

    Energy Technology Data Exchange (ETDEWEB)

    Ocampo, R.; Bauder, C.; Callot, H.J.; Albrecht, P. (Univ. Louis Pasteur, Strasbourg (France))

    1992-02-01

    The extraction and isolation procedures of twenty nickel porphyrins (seven alkylporphyrins, thirteen carboxylic acids) from lacustrine Messel shale (Eocene, Germany), as well as the unequivocal structural assignments (obtained using 200 and 400 MHz nuclear magnetic resonance (NMR), nuclear Overhauser effect, mass spectrometry, and total or partial synthesis of six reference compounds) are described. Ten porphyrins could be specifically correlated with biological precursors: algal chlorophyll c (4), bacteriochlorophylls d (3), and heme (3), while the remaining ones may arise from several chlorophylls. The structures of these fossil pigments mostly confirm the classical Treibs scheme,' including the origin of some porphyrins from nonchlorophyll sources. They also show that, even in a very immature sediment, deep modifications occur, including, in particular, extensive degradation of chlorophyll E ring. The composition of the porphyrin fractions of Messel oil shale was also studied as a function of depth. A porphyrin acids/alkylporphyrins ratio varying from 0.35 to 24.8 demonstrated that the apparent homogeneity of the shale is not reflected on the molecular scale. This was confirmed when the abundance of the twenty individual porphyrins of known structure was measured along the core. Significant correlations between individual porphyrins were found: fossils of bacteriochlorophylls d, homolog pairs of porphyrins (3-H/3-ethyl), etc.

  20. Porphyrins from Messel oil shale (Eocene, Germany): Structure elucidation, geochemical and biological significance, and distribution as a function of depth

    Science.gov (United States)

    Ocampo, Rubén; Bauder, Claude; Callot, Henry J.; Albrecht, Pierre

    1992-02-01

    The extraction and isolation procedures of twenty nickel porphyrins (seven alkylporphyrins, thirteen carboxylic acids) from lacustrine Messel shale (Eocene, Germany), as well as the unequivocal structural assignments (obtained using 200 and 400 MHz nuclear magnetic resonance (NMR), nuclear Overhauser effect, mass spectrometry and total or partial synthesis of six reference compounds) are described. Ten porphyrins could be specifically correlated with biological precursors: algal chlorophyll c (4), bacteriochlorophylls d (3) and heme (3), while the remaining ones may arise from several chlorophylls. The structures of these fossil pigments mostly confirm the classical "Treibs scheme," including the origin of some porphyrins from nonchlorophyll sources. They also show that, even in a very immature sediment, deep modifications occur, including, in particular, extensive degradation of chlorophyll E ring. The composition of the porphyrin fractions of Messel oil shale was also studied as a function of depth. A porphyrin acids/alkylporphyrins ratio varying from 0.35 to 24.8 demonstrated that the apparent homogeneity of the shale is not reflected on the molecular scale. This was confirmed when the abundance of the twenty individual porphyrins of known structure was measured along the core. Significant correlations between individual porphyrins were found: fossils of bacteriochlorophylls d, homolog pairs of porphyrins (3-H/3-ethyl), etc.

  1. Significant impact of electrical storm on mortality in patients with structural heart disease and an implantable cardiac defibrillator.

    Science.gov (United States)

    Noda, Takashi; Kurita, Takashi; Nitta, Takashi; Chiba, Yasutaka; Furushima, Hiroshi; Matsumoto, Naoki; Toyoshima, Takeshi; Shimizu, Akihiko; Mitamura, Hideo; Okumura, Ken; Ohe, Tohru; Aizawa, Yoshifusa

    2018-03-15

    Electrical storm (E-Storm), defined as multiple episodes of ventricular arrhythmias within a short period of time, is an important clinical problem in patients with an implantable cardiac defibrillator (ICD) including cardiac resynchronization therapy devices capable of defibrillation. The detailed clinical aspects of E-Storm in large populations especially for non-ischemic dilated cardiomyopathy (DCM), however, remain unclear. This study was performed to elucidate the detailed clinical aspects of E-Storm, such as its predictors and prevalence among patients with structural heart disease including DCM. We analyzed the data of the Nippon Storm Study, which was a prospective observational study involving 1570 patients enrolled from 48 ICD centers. For the purpose of this study, we evaluated 1274 patients with structural heart disease, including 482 (38%) patients with ischemic heart disease (IHD) and 342 (27%) patients with DCM. During a median follow-up of 28months (interquartile range: 23 to 33months), E-Storm occurred in 84 (6.6%) patients. The incidence of E-Storm was not significantly different between patients with IHD and patients with DCM (log-rank p=0.52). Proportional hazard regression analyses showed that ICD implantation for secondary prevention of sudden cardiac death (p=0.0001) and QRS width (p=0.015) were the independent risk factors for E-storm. In a comparison between patients with and without E-Storm, survival curves after adjustment for clinical characteristics showed a significant difference in mortality. E-Storm was associated with subsequent mortality in patients with structural heart disease including DCM. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Structure-properties relationships of polyhedral oligomeric silsesquioxane (POSS filled PS nanocomposites

    Directory of Open Access Journals (Sweden)

    J. J. Schwab

    2012-07-01

    Full Text Available The polyhedral oligomeric silsesquioxane (POSS additivated polystyrene (PS based nanocomposites were prepared by melt processing and the structure-properties relationships of the POSS-PS systems were compared to those of the neat PS. In order to investigate the effect of these structural parameters on the final properties of the polymer nanocomposites, five different kinds of POSS samples were used, in particular, POSS with different inorganic cage and with different organic pendent groups. The rheological investigation suggests clearly that the POSS acts as a plasticizer and that the processability of the PS was positively modified. The affinity between the POSS samples and the PS matrix was estimated by the calculated theoretical solubility parameters, considering the Hoy’s method and by morphology analysis. Minor difference between the solubility parameter of POSS and the matrix means better compatibility and no aggregation tendency. Furthermore, the POSS loading leads to a decrease of the rigidity, of the glass transition temperature and of the damping factor of the nanocomposite systems. The loading of different POSS molecules with open cage leads to a more pronounced effect on all the investigated properties that the loading of the POSS molecules with closed cage. Moreover, the melt properties are significantly influenced by the type of inorganic framework, by the type of the pendent organic groups and by the interaction between the POSS organic groups and the host matrix, while, the solid state properties appears to be influenced more by the kind of cage.

  3. Quantitative structure-retention relationships of pesticides in reversed-phase high-performance liquid chromatography

    International Nuclear Information System (INIS)

    Aschi, Massimiliano; D'Archivio, Angelo Antonio; Maggi, Maria Anna; Mazzeo, Pietro; Ruggieri, Fabrizio

    2007-01-01

    In this paper, a quantitative structure-retention relationships (QSRR) method is employed to predict the retention behaviour of pesticides in reversed-phase high-performance liquid chromatography (HPLC). A six-parameter nonlinear model is developed by means of a feed-forward artificial neural network (ANN) with back-propagation learning rule. Accurate description of the retention factors of 26 compounds including commonly used insecticides, herbicides and fungicides and some metabolites is successfully achieved. In addition to the acetonitrile content, included to describe composition of the water-acetonitrile mobile phase, the octanol-water partition coefficient (from literature) and four quantum chemical descriptors are considered to account for the effect of solute structure on the retention. These are: the total dipole moment, the mean polarizability, the anisotropy of polarizability and a descriptor of hydrogen bonding ability based on the atomic charges on hydrogen bond donor and acceptor chemical functionalities. The proposed nonlinear QSRR model exhibits a high degree of correlation between observed and computed retention factors and a good predictive performance in wide range of mobile phase composition (40-65%, v/v acetonitrile) that supports its application for the prediction of the chromatographic behaviour of unknown pesticides. A multilinear regression model based on the same six descriptors shows a significantly worse predictive capability

  4. Quantitative structure-retention relationships of pesticides in reversed-phase high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Aschi, Massimiliano [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy); D' Archivio, Angelo Antonio [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy)]. E-mail: darchivi@univaq.it; Maggi, Maria Anna [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy); Mazzeo, Pietro [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy); Ruggieri, Fabrizio [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy)

    2007-01-23

    In this paper, a quantitative structure-retention relationships (QSRR) method is employed to predict the retention behaviour of pesticides in reversed-phase high-performance liquid chromatography (HPLC). A six-parameter nonlinear model is developed by means of a feed-forward artificial neural network (ANN) with back-propagation learning rule. Accurate description of the retention factors of 26 compounds including commonly used insecticides, herbicides and fungicides and some metabolites is successfully achieved. In addition to the acetonitrile content, included to describe composition of the water-acetonitrile mobile phase, the octanol-water partition coefficient (from literature) and four quantum chemical descriptors are considered to account for the effect of solute structure on the retention. These are: the total dipole moment, the mean polarizability, the anisotropy of polarizability and a descriptor of hydrogen bonding ability based on the atomic charges on hydrogen bond donor and acceptor chemical functionalities. The proposed nonlinear QSRR model exhibits a high degree of correlation between observed and computed retention factors and a good predictive performance in wide range of mobile phase composition (40-65%, v/v acetonitrile) that supports its application for the prediction of the chromatographic behaviour of unknown pesticides. A multilinear regression model based on the same six descriptors shows a significantly worse predictive capability.

  5. The relationship between cognitive processing of affective verbal material and the basic personality structure

    Directory of Open Access Journals (Sweden)

    Orlić Ana

    2010-01-01

    Full Text Available The aim of this study was to investigate the relationship between cognitive processing of affective verbal material and the basic personality structure. For the purposes of research a new experiment was created, where affective priming was measured in a lexical decision task. The term affective priming stands for facilitation in recognition of the stimuli that comes after the presentation of stimuli of the same valence. In this experiment, two words were presented on a screen in front of the subject (stimuli-prime and stimuli-target. Those two words were of the same or different affective valence, and the subject's were instructed to respond whether the second word on the screen had a meaning or not. The basic personality structure was defined by the 'Big five' model and the Disintegration model and measured by NEO PI-R and Delta 10 questionnaires. The results of the affective priming experiment indicated a strong effect of positive facilitation and much weaker effect off negative facilitation. Two significant functions were extracted by quasicanonical correlation analysis. The first function showed correlation between the effect of positive facilitation and all of the subscales of Neuroticism, Extraversion and Conscientiousness (NEO PI-R, as well as all sub dimensions of Disintegration (DELTA 10. The second one indicated to a correlation between the negative facilitation effect and some subscales of Neuroticism, Extraversion and Agreeableness (NEO PI-R, as well as all subscales of Disintegration (DELTA 10.

  6. Combining region- and network-level brain-behavior relationships in a structural equation model.

    Science.gov (United States)

    Bolt, Taylor; Prince, Emily B; Nomi, Jason S; Messinger, Daniel; Llabre, Maria M; Uddin, Lucina Q

    2018-01-15

    Brain-behavior associations in fMRI studies are typically restricted to a single level of analysis: either a circumscribed brain region-of-interest (ROI) or a larger network of brain regions. However, this common practice may not always account for the interdependencies among ROIs of the same network or potentially unique information at the ROI-level, respectively. To account for both sources of information, we combined measurement and structural components of structural equation modeling (SEM) approaches to empirically derive networks from ROI activity, and to assess the association of both individual ROIs and their respective whole-brain activation networks with task performance using three large task-fMRI datasets and two separate brain parcellation schemes. The results for working memory and relational tasks revealed that well-known ROI-performance associations are either non-significant or reversed when accounting for the ROI's common association with its corresponding network, and that the network as a whole is instead robustly associated with task performance. The results for the arithmetic task revealed that in certain cases, an ROI can be robustly associated with task performance, even when accounting for its associated network. The SEM framework described in this study provides researchers additional flexibility in testing brain-behavior relationships, as well as a principled way to combine ROI- and network-levels of analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. The relationship between dental implant stability and trabecular bone structure using cone-beam computed tomography

    Science.gov (United States)

    2016-01-01

    Purpose The objective of this study was to investigate the relationships between primary implant stability as measured by impact response frequency and the structural parameters of trabecular bone using cone-beam computed tomography(CBCT), excluding the effect of cortical bone thickness. Methods We measured the impact response of a dental implant placed into swine bone specimens composed of only trabecular bone without the cortical bone layer using an inductive sensor. The peak frequency of the impact response spectrum was determined as an implant stability criterion (SPF). The 3D microstructural parameters were calculated from CT images of the bone specimens obtained using both micro-CT and CBCT. Results SPF had significant positive correlations with trabecular bone structural parameters (BV/TV, BV, BS, BSD, Tb.Th, Tb.N, FD, and BS/BV) (Pmicro-CT and CBCT (Pimplant stability prediction by combining BV/TV and SMI in the stepwise forward regression analysis. Bone with high volume density and low surface density shows high implant stability. Well-connected thick bone with small marrow spaces also shows high implant stability. The combination of bone density and architectural parameters measured using CBCT can predict the implant stability more accurately than the density alone in clinical diagnoses. PMID:27127692

  8. The Relationship between Self-Leadership and Personality: A Comparison of Hierarchical Factor Structures

    OpenAIRE

    Houghton, Jeffery D.

    2000-01-01

    This study examined the relationship between self-leadership and personality through an analysis and comparison of hierarchical factor structures. More specifically, this study examined the relationships between the self-leadership dimensions of behavior-focused strategies, natural reward strategies, and constructive thought strategies, and the personality dimensions of extraversion, emotional stability, and conscientiousness. The results of the study provide evidence that the self-leadershi...

  9. Rare-earth transition-metal intermetallics: Structure-bonding-property relationships

    Energy Technology Data Exchange (ETDEWEB)

    Han, M. K. [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    The explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding property relationships. The work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe13-xSix system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabilizing the structure and controlling the transformation of cubic NaZn{sub 13}-type structures to the tetragonal derivative, as well as the relationship between the structures and properties. (2) Synthesis of new ternary rare-earth iron silicides Re2-xFe4Si14-y and proposed superstructure: This compound offers complex structural challenges such as fractional occupancies and their ordering in superstructure. (3) Electronic structure calculation of FeSi2: This shows that the metal-semiconductor phase transition depends on the structure. The mechanism of band gap opening is described in terms of bonding and structural distortion. This result shows that the electronic structure calculations are an essential tool for understanding the relationship between structure and chemical bonding in these compounds. (4) Synthesis of new ternary rare-earth Zinc aluminides Tb3Zn3.6Al7.4: Partially ordered structure of Tb3Zn3.6Al7.4 compound provides new insights into the formation, composition and structure of rare-earth transition-metal intermetallics. Electronic structure calculations attribute the observed composition to optimizing metal-metal bonding in the electronegative (Zn, Al) framework, while the specific ordering is strongly influenced by specific orbital interactions. (5) Synthesis of new structure type of Zn39(CrxAl1-x)81

  10. Rare-Earth Transition-Metal Intermetallics: Structure-bonding-Property Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Han, Mi-Kyung [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    Our explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding-property relationships. Our work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe13-xSix system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabilizing the structure and controlling the transformation of cubic NaZn13-type structures to the tetragonal derivative, as well as the relationship between the structures and properties. (2) Synthesis of new ternary rare-earth iron silicides RE2-xFe4Si14-y and proposed superstructure: This compound offers complex structural challenges such as fractional occupancies and their ordering in superstructure. (3) Electronic structure calculation of FeSi2: This shows that the metal-semiconductor phase transition depends on the structure. The mechanism of band gap opening is described in terms of bonding and structural distortion. This result shows that the electronic structure calculations are an essential tool for understanding the relationship between structure and chemical bonding in these compounds. (4) Synthesis of new ternary rare-earth Zinc aluminides Tb3Zn3.6Al7.4: Partially ordered structure of Tb3.6Zn13-xAl7.4 compound provides new insights into the formation, composition and structure of rare-earth transition-metal intermetallics. Electronic structure calculations attribute the observed composition to optimizing metal-metal bonding in the electronegative (Zn, Al) framework, while the specific ordering is strongly influenced by specific orbital interactions. (5) Synthesis of new structure type of Zn39(CrxAl1-x

  11. Quantitative Structure-Activity Relationships and Docking Studies of Calcitonin Gene-Related Peptide Antagonists

    DEFF Research Database (Denmark)

    Jenssen, Håvard; Mehrabian, Mohadeseh; Kyani, Anahita

    2012-01-01

    Defining the role of calcitonin gene-related peptide in migraine pathogenesis could lead to the application of calcitonin gene-related peptide antagonists as novel migraine therapeutics. In this work, quantitative structure-activity relationship modeling of biological activities of a large range...... of calcitonin gene-related peptide antagonists was performed using a panel of physicochemical descriptors. The computational studies evaluated different variable selection techniques and demonstrated shuffling stepwise multiple linear regression to be superior over genetic algorithm-multiple linear regression....... The linear quantitative structure-activity relationship model revealed better statistical parameters of cross-validation in comparison with the non-linear support vector regression technique. Implementing only five peptide descriptors into this linear quantitative structure-activity relationship model...

  12. Quantitative structure-retention relationship studies using immobilized artificial membrane chromatography I: amended linear solvation energy relationships with the introduction of a molecular electronic factor.

    Science.gov (United States)

    Li, Jie; Sun, Jin; Cui, Shengmiao; He, Zhonggui

    2006-11-03

    Linear solvation energy relationships (LSERs) amended by the introduction of a molecular electronic factor were employed to establish quantitative structure-retention relationships using immobilized artificial membrane (IAM) chromatography, in particular ionizable solutes. The chromatographic indices, log k(IAM), were determined by HPLC on an IAM.PC.DD2 column for 53 structurally diverse compounds, including neutral, acidic and basic compounds. Unlike neutral compounds, the IAM chromatographic retention of ionizable compounds was affected by their molecular charge state. When the mean net charge per molecule (delta) was introduced into the amended LSER as the sixth variable, the LSER regression coefficient was significantly improved for the test set including ionizable solutes. The delta coefficients of acidic and basic compounds were quite different indicating that the molecular electronic factor had a markedly different impact on the retention of acidic and basic compounds on IAM column. Ionization of acidic compounds containing a carboxylic group tended to impair their retention on IAM, while the ionization of basic compounds did not have such a marked effect. In addition, the extra-interaction with the polar head of phospholipids might cause a certain change in the retention of basic compounds. A comparison of calculated and experimental retention indices suggested that the semi-empirical LSER amended by the addition of a molecular electronic factor was able to reproduce adequately the experimental retention factors of the structurally diverse solutes investigated.

  13. Sequence-structure relationships in RNA loops: establishing the basis for loop homology modeling.

    Science.gov (United States)

    Schudoma, Christian; May, Patrick; Nikiforova, Viktoria; Walther, Dirk

    2010-01-01

    The specific function of RNA molecules frequently resides in their seemingly unstructured loop regions. We performed a systematic analysis of RNA loops extracted from experimentally determined three-dimensional structures of RNA molecules. A comprehensive loop-structure data set was created and organized into distinct clusters based on structural and sequence similarity. We detected clear evidence of the hallmark of homology present in the sequence-structure relationships in loops. Loops differing by structures. Thus, our results support the application of homology modeling for RNA loop model building. We established a threshold that may guide the sequence divergence-based selection of template structures for RNA loop homology modeling. Of all possible sequences that are, under the assumption of isosteric relationships, theoretically compatible with actual sequences observed in RNA structures, only a small fraction is contained in the Rfam database of RNA sequences and classes implying that the actual RNA loop space may consist of a limited number of unique loop structures and conserved sequences. The loop-structure data sets are made available via an online database, RLooM. RLooM also offers functionalities for the modeling of RNA loop structures in support of RNA engineering and design efforts.

  14. On the relationship between justice judgments, outcomes and identity orientations among Iranian EFL learners: A structural equation model

    Directory of Open Access Journals (Sweden)

    Seyyed Ayatollah Razmjoo

    2015-06-01

    Full Text Available One problem which can be observed in the field of EFL/ESL learning is that a number of English major BA and MA students are not highly committed to their major and decide not to continue their graduate studies. Sometimes even graduate students from English majors prefer to extend their education or work in an unrelated field. This might be attributed to the extent to which they perceive evaluation procedures and outcomes as fair. Considering this, the present study investigates first the relationships between justice judgments, outcomes and identity orientations. The study, then, uses structural equation modeling in order to examine whether identity orientation has any mediating effect on the relationship between justice judgment and outcomes. Participants were74 students in Department of Foreign Languages and Linguistics, Shiraz University selected based on convenience sampling. They filled out three questionnaires on distributive and procedural justice judgments, rule compliance and outcome satisfaction, and personal and social identity orientations. The collected data was then analyzed using descriptive statistics, correlation, and structural equation modeling. Based on the obtained findings, procedural justice had significant positive correlation with rule compliance and distributive justice was significantly correlated with outcome satisfaction. The generated structural equation model also indicated that justice judgments only directly affected outcomes and identity had no mediating effect on the causal relationship between the two.

  15. Mapping the Structure-Function Relationship in Glaucoma and Healthy Patients Measured with Spectralis OCT and Humphrey Perimetry

    Science.gov (United States)

    Muñoz–Negrete, Francisco J.; Oblanca, Noelia; Rebolleda, Gema

    2018-01-01

    Purpose To study the structure-function relationship in glaucoma and healthy patients assessed with Spectralis OCT and Humphrey perimetry using new statistical approaches. Materials and Methods Eighty-five eyes were prospectively selected and divided into 2 groups: glaucoma (44) and healthy patients (41). Three different statistical approaches were carried out: (1) factor analysis of the threshold sensitivities (dB) (automated perimetry) and the macular thickness (μm) (Spectralis OCT), subsequently applying Pearson's correlation to the obtained regions, (2) nonparametric regression analysis relating the values in each pair of regions that showed significant correlation, and (3) nonparametric spatial regressions using three models designed for the purpose of this study. Results In the glaucoma group, a map that relates structural and functional damage was drawn. The strongest correlation with visual fields was observed in the peripheral nasal region of both superior and inferior hemigrids (r = 0.602 and r = 0.458, resp.). The estimated functions obtained with the nonparametric regressions provided the mean sensitivity that corresponds to each given macular thickness. These functions allowed for accurate characterization of the structure-function relationship. Conclusions Both maps and point-to-point functions obtained linking structure and function damage contribute to a better understanding of this relationship and may help in the future to improve glaucoma diagnosis. PMID:29850196

  16. Structure-function relationship in complex brain networks expressed by hierarchical synchronization

    International Nuclear Information System (INIS)

    Zhou Changsong; Zemanova, Lucia; Zamora-Lopez, Gorka; Hilgetag, Claus C; Kurths, Juergen

    2007-01-01

    The brain is one of the most complex systems in nature, with a structured complex connectivity. Recently, large-scale corticocortical connectivities, both structural and functional, have received a great deal of research attention, especially using the approach of complex network analysis. Understanding the relationship between structural and functional connectivity is of crucial importance in neuroscience. Here we try to illuminate this relationship by studying synchronization dynamics in a realistic anatomical network of cat cortical connectivity. We model the nodes (cortical areas) by a neural mass model (population model) or by a subnetwork of interacting excitable neurons (multilevel model). We show that if the dynamics is characterized by well-defined oscillations (neural mass model and subnetworks with strong couplings), the synchronization patterns are mainly determined by the node intensity (total input strengths of a node) and the detailed network topology is rather irrelevant. On the other hand, the multilevel model with weak couplings displays more irregular, biologically plausible dynamics, and the synchronization patterns reveal a hierarchical cluster organization in the network structure. The relationship between structural and functional connectivity at different levels of synchronization is explored. Thus, the study of synchronization in a multilevel complex network model of cortex can provide insights into the relationship between network topology and functional organization of complex brain networks

  17. Structure-function relationship in complex brain networks expressed by hierarchical synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Changsong [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany); Zemanova, Lucia [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany); Zamora-Lopez, Gorka [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany); Hilgetag, Claus C [Jacobs University Bremen, Campus Ring 6, Rm 116, D-28759 Bremen (Germany); Kurths, Juergen [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany)

    2007-06-15

    The brain is one of the most complex systems in nature, with a structured complex connectivity. Recently, large-scale corticocortical connectivities, both structural and functional, have received a great deal of research attention, especially using the approach of complex network analysis. Understanding the relationship between structural and functional connectivity is of crucial importance in neuroscience. Here we try to illuminate this relationship by studying synchronization dynamics in a realistic anatomical network of cat cortical connectivity. We model the nodes (cortical areas) by a neural mass model (population model) or by a subnetwork of interacting excitable neurons (multilevel model). We show that if the dynamics is characterized by well-defined oscillations (neural mass model and subnetworks with strong couplings), the synchronization patterns are mainly determined by the node intensity (total input strengths of a node) and the detailed network topology is rather irrelevant. On the other hand, the multilevel model with weak couplings displays more irregular, biologically plausible dynamics, and the synchronization patterns reveal a hierarchical cluster organization in the network structure. The relationship between structural and functional connectivity at different levels of synchronization is explored. Thus, the study of synchronization in a multilevel complex network model of cortex can provide insights into the relationship between network topology and functional organization of complex brain networks.

  18. Surface-Based fMRI-Driven Diffusion Tractography in the Presence of Significant Brain Pathology: A Study Linking Structure and Function in Cerebral Palsy

    Science.gov (United States)

    Cunnington, Ross; Boyd, Roslyn N.; Rose, Stephen E.

    2016-01-01

    Diffusion MRI (dMRI) tractography analyses are difficult to perform in the presence of brain pathology. Automated methods that rely on cortical parcellation for structural connectivity studies often fail, while manually defining regions is extremely time consuming and can introduce human error. Both methods also make assumptions about structure-function relationships that may not hold after cortical reorganisation. Seeding tractography with functional-MRI (fMRI) activation is an emerging method that reduces these confounds, but inherent smoothing of fMRI signal may result in the inclusion of irrelevant pathways. This paper describes a novel fMRI-seeded dMRI-analysis pipeline based on surface-meshes that reduces these issues and utilises machine-learning to generate task specific white matter pathways, minimising the requirement for manually-drawn ROIs. We directly compared this new strategy to a standard voxelwise fMRI-dMRI approach, by investigating correlations between clinical scores and dMRI metrics of thalamocortical and corticomotor tracts in 31 children with unilateral cerebral palsy. The surface-based approach successfully processed more participants (87%) than the voxel-based approach (65%), and provided significantly more-coherent tractography. Significant correlations between dMRI metrics and five clinical scores of function were found for the more superior regions of these tracts. These significant correlations were stronger and more frequently found with the surface-based method (15/20 investigated were significant; R2 = 0.43–0.73) than the voxelwise analysis (2 sig. correlations; 0.38 & 0.49). More restricted fMRI signal, better-constrained tractography, and the novel track-classification method all appeared to contribute toward these differences. PMID:27487011

  19. Processing information about support exchanges in close relationships: The role of a knowledge structure

    Directory of Open Access Journals (Sweden)

    Bulent eTuran

    2016-02-01

    Full Text Available People develop knowledge of interpersonal interaction patterns (e.g., prototypes and schemas, which shape how they process incoming information. One such knowledge structure based on attachment theory was examined: the secure base script (the prototypic sequence of events when an attachment figure comforts a close relationship partner in distress. In two studies (N = 53 and N = 119, participants were shown animated film clips in which geometric figures depicted the secure base script and asked to describe the animations. Both studies found that many people readily recognize the secure-base script from these minimal cues quite well, suggesting that this script is not only available in the context of specific relationships (i.e., a relationship-specific knowledge: The generalized (abstract structure of the script is also readily accessible, which would make it possible to apply it to any relationship (including new relationships. Regression analyses suggested that participants who recognized the script were more likely to (a include more animation elements when describing the animations, (b see a common theme in different animations, (c create better organized stories, and (d later recall more details of the animations. These findings suggest that access to this knowledge structure helps a person organize and remember relevant incoming information. Furthermore, in both Study 1 and Study 2, individual differences in the ready recognition of the script were associated with individual differences in having access to another related knowledge: indicators suggesting that a potential relationship partner can be trusted to be supportive and responsive at times of stress. Results of Study 2 also suggest that recognizing the script is associated with those items of an attachment measure that concern giving and receiving support. Thus, these knowledge structures may shape how people process support-relevant information in their everyday lives, potentially

  20. [The relationship between eyeball structure and visual acuity in high myopia].

    Science.gov (United States)

    Liu, Yi-Chang; Xia, Wen-Tao; Zhu, Guang-You; Zhou, Xing-Tao; Fan, Li-Hua; Liu, Rui-Jue; Chen, Jie-Min

    2010-06-01

    To explore the relationship between eyeball structure and visual acuity in high myopia. Totally, 152 people (283 eyeballs) with different levels of myopia were tested for visual acuity, axial length, and fundus. All cases were classified according to diopter, axial length, and fundus. The relationships between diopter, axial length, fundus and visual acuity were studied. The mathematical models were established for visual acuity and eyeball structure markers. The visual acuity showed a moderate correlation with fundus class, comus, axial length and diopter ([r] > 0.4, P eyeball structure markers. The visual acuity should decline with axial length extension, diopter deepening and pathological deterioration of fundus. To detect the structure changes by combining different kinds of objective methods can help to assess and to judge the vision in high myopia.

  1. The Relationship between Ownership Structure and Risk Management: Evidence from Iran

    OpenAIRE

    Sheyda Lotfi; Ataollah Mohammadi

    2014-01-01

    This research aims to study the relationship between the Ownership Structure and Risk Management in time period between 2007 to 2013 based on a sample including 642 Year_Firm among campanies listed in Tehran Stock Exchange. In following for each of the variables related to the Ownership Structure such as Institutional Ownership, Management ownership, Family Ownership, and Ownership Concentration, a hypothesis is formulated and its impact upon the Risk Management is investigated. The simple li...

  2. Structure-function relationships in elderly resting-state-networks : influence of age and cognitive performance

    OpenAIRE

    Jockwitz, Christiane

    2016-01-01

    The aim of this work was to investigate the structure-function relationship in cognitive resting state networks in a large population-based elderly sample. The first study characterized the functional connectivity in four cognitive resting state networks with respect to age, gender and cognitive performance: Default Mode Network (DMN), executive, and left and right frontoparietal resting state networks. The second study assessed the structural correlates of the functional reorganization of th...

  3. Analysis of the relationships among trust antecedents, organizational structures, and performance outcomes

    OpenAIRE

    Seykora, Joseph T.

    2009-01-01

    Approved for public release, distribution unlimited MBA Professional Report The project explores and seeks to identify relationships among four trust antecedents, two organizational structures, and two performance outcomes. The results will help to further explain associations between trust level (high or low) and organizational structure. Past research found that the edge organization operating in a high trust environment produces the most accurate results in the least amount of time. ...

  4. Significance of size dependent and material structure coupling on the characteristics and performance of nanocrystalline micro/nano gyroscopes

    Science.gov (United States)

    Larkin, K.; Ghommem, M.; Abdelkefi, A.

    2018-05-01

    Capacitive-based sensing microelectromechanical (MEMS) and nanoelectromechanical (NEMS) gyroscopes have significant advantages over conventional gyroscopes, such as low power consumption, batch fabrication, and possible integration with electronic circuits. However, inadequacies in the modeling of these inertial sensors have presented issues of reliability and functionality of micro-/nano-scale gyroscopes. In this work, a micromechanical model is developed to represent the unique microstructure of nanocrystalline materials and simulate the response of micro-/nano-gyroscope comprising an electrostatically-actuated cantilever beam with a tip mass at the free end. Couple stress and surface elasticity theories are integrated into the classical Euler-Bernoulli beam model in order to derive a size-dependent model. This model is then used to investigate the influence of size-dependent effects on the static pull-in instability, the natural frequencies and the performance output of gyroscopes as the scale decreases from micro-to nano-scale. The simulation results show significant changes in the static pull-in voltage and the natural frequency as the scale of the system is decreased. However, the differential frequency between the two vibration modes of the gyroscope is observed to drastically decrease as the size of the gyroscope is reduced. As such, the frequency-based operation mode may not be an efficient strategy for nano-gyroscopes. The results show that a strong coupling between the surface elasticity and material structure takes place when smaller grain sizes and higher void percentages are considered.

  5. Structure Matters: The Role of Clique Hierarchy in the Relationship Between Adolescent Social Status and Aggression and Prosociality.

    Science.gov (United States)

    Pattiselanno, Kim; Dijkstra, Jan Kornelis; Steglich, Christian; Vollebergh, Wilma; Veenstra, René

    2015-12-01

    Peer cliques form an important context for the social development of adolescents. Although clique members are often similar in social status, also within cliques, status differences exist. How differences in social status between clique members are related to behaviors of its individual members is rather unknown. This study examined to what extent the relationship of individual social status (i.e., perceived popularity) with aggression and prosocial behavior depends on the level of internal clique hierarchy. The sample consists of 2674 adolescents (49.8% boys), with a mean age of 14.02. We focused specifically on physical and relational aggression, and practical and emotional support, because these behaviors have shown to be of great importance for social relationships and social standing among adolescents. The internal status hierarchy of cliques was based on the variation in individual social status between clique members (i.e., clique hierarchization) and the structure of status scores within a clique (pyramid shape, inverted pyramid, or equal distribution of social status scores) (i.e., clique status structure). The results showed that differences in aggressive and prosocial behaviors were particularly moderated by clique status structure: aggression was stronger related to individual social status in (girls') cliques where the clique status structure reflected an inverted pyramid with relatively more high status adolescents within the clique than low status peers, and prosocial behavior showed a significant relationship with individual social status, again predominantly in inverted pyramid structured (boys' and girls') cliques. Furthermore, these effects differed by types of gender cliques: the associations were found in same gender but not mixed-gender cliques. The findings stress the importance of taking into account internal clique characteristics when studying adolescent social status in relationship to aggression and prosociality.

  6. Structure-solubility relationships in fluoride-containing phosphate based bioactive glasses

    Science.gov (United States)

    Shaharyar, Yaqoot

    The dissolution of fluoride-containing bioactive glasses critically affects their biomedical applications. Most commercial fluoride-releasing bioactive glasses have been designed in the soda-lime-silica system. However, their relatively slow chemical dissolution and the adverse effect of fluoride on their bioactivity are stimulating the study of novel biodegradable materials with higher bioactivity, such as biodegradable phosphate-based bioactive glasses, which can be a viable alternative for applications where a fast release of active ions is sought. In order to design new biomaterials with controlled degradability and high bioactivity, it is essential to understand the connection between chemical composition, molecular structure, and solubility in physiological fluids.Accordingly, in this work we have combined the strengths of various experimental techniques with Molecular Dynamics (MD) simulations, to elucidate the impact of fluoride ions on the structure and chemical dissolution of bioactive phosphate glasses in the system: 10Na2O - (45-x) CaO - 45P2O5 - xCaF2, where x varies between 0 -- 10 mol.%. NMR and MD data reveal that the medium-range atomic-scale structure of thse glasses is dominated by Q2 phosphate units followed by Q1 units, and the MD simulations further show that fluoride tends to associate with network modifier cations to form alkali/alkaline-earth rich ionic aggregates. On a macroscopic scale, we find that incorporating fluoride in phosphate glasses does not affect the rate of apatite formation on the glass surface in simulated body fluid (SBF). However, fluoride has a marked favorable impact on the glass dissolution in deionized water. Similarly, fluoride incorporation in the glasses results in significant weight gain due to adsorption of water (in the form of OH ions). These macroscopic trends are discussed on the basis of the F effect on the atomistic structure of the glasses, such as the F-induced phosphate network re-polymerization, in a

  7. Quantitative structure-activity relationship (QSAR) models for polycyclic aromatic hydrocarbons (PAHs) dissipation in rhizosphere based on molecular structure and effect size

    International Nuclear Information System (INIS)

    Ma Bin; Chen Huaihai; Xu Minmin; Hayat, Tahir; He Yan; Xu Jianming

    2010-01-01

    Rhizoremediation is a significant form of bioremediation for polycyclic aromatic hydrocarbons (PAHs). This study examined the role of molecular structure in determining the rhizosphere effect on PAHs dissipation. Effect size in meta-analysis was employed as activity dataset for building quantitative structure-activity relationship (QSAR) models and accumulative effect sizes of 16 PAHs were used for validation of these models. Based on the genetic algorithm combined with partial least square regression, models for comprehensive dataset, Poaceae dataset, and Fabaceae dataset were built. The results showed that information indices, calculated as information content of molecules based on the calculation of equivalence classes from the molecular graph, were the most important molecular structural indices for QSAR models of rhizosphere effect on PAHs dissipation. The QSAR model, based on the molecular structure indices and effect size, has potential to be used in studying and predicting the rhizosphere effect of PAHs dissipation. - Effect size based on meta-analysis was used for building PAHs dissipation quantitative structure-activity relationship (QSAR) models.

  8. Quantitative structure-activity relationship (QSAR) models for polycyclic aromatic hydrocarbons (PAHs) dissipation in rhizosphere based on molecular structure and effect size

    Energy Technology Data Exchange (ETDEWEB)

    Ma Bin; Chen Huaihai; Xu Minmin; Hayat, Tahir [Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Natural Resource Sciences, Zhejiang University, Hangzhou 310029 (China); He Yan, E-mail: yhe2006@zju.edu.c [Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Natural Resource Sciences, Zhejiang University, Hangzhou 310029 (China); Xu Jianming, E-mail: jmxu@zju.edu.c [Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Natural Resource Sciences, Zhejiang University, Hangzhou 310029 (China)

    2010-08-15

    Rhizoremediation is a significant form of bioremediation for polycyclic aromatic hydrocarbons (PAHs). This study examined the role of molecular structure in determining the rhizosphere effect on PAHs dissipation. Effect size in meta-analysis was employed as activity dataset for building quantitative structure-activity relationship (QSAR) models and accumulative effect sizes of 16 PAHs were used for validation of these models. Based on the genetic algorithm combined with partial least square regression, models for comprehensive dataset, Poaceae dataset, and Fabaceae dataset were built. The results showed that information indices, calculated as information content of molecules based on the calculation of equivalence classes from the molecular graph, were the most important molecular structural indices for QSAR models of rhizosphere effect on PAHs dissipation. The QSAR model, based on the molecular structure indices and effect size, has potential to be used in studying and predicting the rhizosphere effect of PAHs dissipation. - Effect size based on meta-analysis was used for building PAHs dissipation quantitative structure-activity relationship (QSAR) models.

  9. Relationship between the structural stability with the types and land uses in southeastern Spain

    International Nuclear Information System (INIS)

    Marin Sanleandro, P.; Sanchez Navarro, A.; Delgado Iniesta, M. J.; Fernandez-Delgado Juarez, M.

    2009-01-01

    Structural stability is one of the most important physical properties and is proposed as an indicator of quality. The aim of this study is to see the possible relationship between this property with soil types and uses of them. In this paper we have selected the Mazarron area based on their environmental characteristics and has taken forty-one topsoil samples, after analysis and study of the relationship between its structural stability with soil types and uses of same, we find a closer relationship in the case of uses that type, so that the natural soil as the percentage of stable aggregates close to 75%, while in soils anthropized this value reaches 44 %. (Author) 6 refs

  10. The Relationship of Bureaucratic Structure to School Climate: An Exploratory Factor Analysis of Construct Validity

    Science.gov (United States)

    Lennon, Patricia A.

    2010-01-01

    This researcher examined the relationship of bureaucratic structure to school climate by means of an exploratory factor analysis of a measure of bureaucracy developed by Hoy and Sweetland (2000) and the four dimensional measure of climate developed by Hoy, Smith, and Sweetland (2002). Since there had been no other empirical studies whose authors…

  11. Customer over employee? : the implications of Customer Relationship Management (CRM) for organisational structures and labour quality

    NARCIS (Netherlands)

    Kwakkelstein, T.

    2002-01-01

    This paper for the Emergence WWWe (The World, the Workplace and We, the workers)-Conference E-Work in a Global World, Brussels 16 & 17 April 2002, explores the effects of the increasing popular ICT application suite Customer Relationship Management (CRM) on organisational structures, corporate

  12. Multi-Structural Relationships among Organizational Culture, Job Autonomy, and CTE Teacher Turnover Intention

    Science.gov (United States)

    Song, Ji Hoon; Martens, Jon; McCharen, Belinda; Ausburn, Lynna J.

    2011-01-01

    This study investigated structural relationships among the constructs of supportive learning culture, school innovative climate, task-related job autonomy, and teacher turnover intention in career and technical education. The study applied organizational concepts to a problem typically approached from the perspective of teacher characteristics and…

  13. Relationship between Professional Learning Community, Bureaucratic Structure and Organisational Trust in Primary Education Schools

    Science.gov (United States)

    Kalkan, Fatma

    2016-01-01

    This research uses relational survey method to determine the relationship between professional learning community, bureaucratic structure and organisational trust according to the perceptions of teachers who work in primary education schools. Data were collected from 805 teachers who work in primary education schools in the districts (Altindag,…

  14. Relationships among Adolescents' Leisure Motivation, Leisure Involvement, and Leisure Satisfaction: A Structural Equation Model

    Science.gov (United States)

    Chen, Ying-Chieh; Li, Ren-Hau; Chen, Sheng-Hwang

    2013-01-01

    The purpose of this cross-sectional study was to test a cause-and-effect model of factors affecting leisure satisfaction among Taiwanese adolescents. A structural equation model was proposed in which the relationships among leisure motivation, leisure involvement, and leisure satisfaction were explored. The study collected data from 701 adolescent…

  15. Relationship between Online Learning Readiness and Structure and Interaction of Online Learning Students

    Science.gov (United States)

    Demir Kaymak, Zeliha; Horzum, Mehmet Baris

    2013-01-01

    Current study tried to determine whether a relationship exists between readiness levels of the online learning students for online learning and the perceived structure and interaction in online learning environments. In the study, cross sectional survey model was used. The study was conducted with 320 voluntary students studying online learning…

  16. Affective Structures among Students and Its Relationship with Academic Burnout with Emphasis on Gender

    Science.gov (United States)

    Bikar, Somaye; Marziyeh, Afsaneh; Pourghaz, Abdolwahab

    2018-01-01

    This study aimed to determine the relationship between affective structures and academic burnout among male and female third-grade high school students in Zahedan in the academic year 2016-2017. The current descriptive-correlational study had a sample including 362 students selected using a multistage cluster sampling method. To collect data,…

  17. The relationship between context, structure, and processes with outcomes of 6 regional diabetes networks in Europe

    NARCIS (Netherlands)

    Mahdavi, M. (Mahdi); J. Vissers (Jan); S. Elkhuizen (Sylvia); Van Dijk, M. (Mattees); Vanhala, A. (Antero); Karampli, E. (Eleftheria); R. Faubel (Raquel); P. Forte (Paul); Coroian, E. (Elena); J.J. van de Klundert (Joris)

    2018-01-01

    textabstractBackground While health service provisioning for the chronic condition Type 2 Diabetes (T2D) often involves a network of organisations and professionals, most evidence on the relationships between the structures and processes of service provisioning and the outcomes considers single

  18. Multivariate quantitative structure-pharmacokinetic relationships (QSPKR) analysis of adenosine A(1) receptor agonists in rat

    NARCIS (Netherlands)

    Van der Graaf, PH; Nilsson, J; Van Schaick, EA; Danhof, M

    The aim of this study was to investigate the feasibility of a quantitative structure-pharmacokinetic relationships (QSPKR) method based on contemporary three-dimensional (3D) molecular characterization and multivariate statistical analysis. For this purpose, the programs SYBYL/CoMFA, GRID, and

  19. Students' Demand for Smartphones: Structural Relationships of Product Features, Brand Name, Product Price and Social Infuence

    Science.gov (United States)

    Suki, Norazah Mohd

    2013-01-01

    Purpose: The study aims to examine structural relationships of product features, brand name, product price and social influence with demand for Smartphones among Malaysian students'. Design/methodology/approach: Data collected from 320 valid pre-screened university students studying at the pubic higher learning institution in Federal Territory of…

  20. A biology-based approach for quantitative structure-activity relationships (QSARs) in ecotoxicity.

    NARCIS (Netherlands)

    Jager, T.; Kooijman, S.A.L.M.

    2009-01-01

    Quantitative structure-activity relationships (QSARs) for ecotoxicity can be used to fill data gaps and limit toxicity testing on animals. QSAR development may additionally reveal mechanistic information based on observed patterns in the data. However, the use of descriptive summary statistics for

  1. The Sport Commitment Model: An Investigation of Structural Relationships with Thai Youth Athlete Populations

    Science.gov (United States)

    Choosakul, Chairat; Vongjaturapat, Naruepon; Li, Fuzhong; Harmer, Peter

    2009-01-01

    Grounded in the conceptual framework of the Sport Commitment Model and previous empirical studies conducted in Western countries, this study was designed to (a) test and validate a Thai version of the Athlete Opinion Survey to assess components of the Sport Commitment Model in Thai youth athletes and (b) examine structural relationships among…

  2. The Structure of Phonological Processing and Its Relationship to Basic Reading

    Science.gov (United States)

    Nelson, Jason M.; Lindstrom, Jennifer H.; Lindstrom, Will; Denis, Daniel

    2012-01-01

    We investigated various structural models of phonological processing and the relationship of phonological processing abilities to basic reading. Data were collected on 116 kindergarten and first grade students. The specific ability model, which included phonological awareness, phonological memory, and rapid automatized naming as separate…

  3. Structural Relationships among E-Learners' Sense of Presence, Usage, Flow, Satisfaction, and Persistence

    Science.gov (United States)

    Joo, Young Ju; Joung, Sunyoung; Kim, Eun Kyung

    2013-01-01

    This study aimed to investigate the structural relationships among teaching presence, cognitive presence, usage, learning flow, satisfaction, and learning persistence in corporate e-learners. The research participants were 462 e-learners registered for cyber-lectures through an electronics company in South Korea. The extrinsic variables were sense…

  4. Structural Features of Sibling Dyads and Attitudes toward Sibling Relationships in Young Adulthood

    Science.gov (United States)

    Riggio, Heidi R.

    2006-01-01

    This study examined sibling-dyad structural variables (sex composition, age difference, current coresidence, position adjacency, family size, respondent and/or sibling ordinal position) and attitudes toward adult sibling relationships. A sample of 1,053 young adults (M age = 22.1 years) described one sibling using the Lifespan Sibling Relationship…

  5. Environmental properties of long-chain alcohols. Structure-activity Relationship for Chronic Aquatic Toxicity

    DEFF Research Database (Denmark)

    Schaefers, Christoph; Sanderson, Hans; Boshof, Udo

    2009-01-01

    Daphnia magna reproduction tests were performed with C10, C12, C14 and C15 alcohols to establish a structure-activity relationship of chronic effects of long-chain alcohols. The data generation involved substantial methodological efforts due to the exceptionally rapid biodegradability of the test...

  6. 3-cyanoindole-based inhibitors of inosine monophosphate dehydrogenase: synthesis and initial structure-activity relationships.

    Science.gov (United States)

    Dhar, T G Murali; Shen, Zhongqi; Gu, Henry H; Chen, Ping; Norris, Derek; Watterson, Scott H; Ballentine, Shelley K; Fleener, Catherine A; Rouleau, Katherine A; Barrish, Joel C; Townsend, Robert; Hollenbaugh, Diane L; Iwanowicz, Edwin J

    2003-10-20

    A series of novel small molecule inhibitors of inosine monophosphate dehydrogenase (IMPDH), based upon a 3-cyanoindole core, were explored. IMPDH catalyzes the rate determining step in guanine nucleotide biosynthesis and is a target for anticancer, immunosuppressive and antiviral therapy. The synthesis and the structure-activity relationships (SAR), derived from in vitro studies, for this new series of inhibitors is given.

  7. Processing-structure-property relationships of carbon nanotube and nanoplatelet enabled piezoresistive sensors

    Science.gov (United States)

    Luo, Sida

    Individual carbon nanotubes (CNTs) possess excellent piezoresistive performance, which is manifested by the significant electrical resistance change when subject to mechanical deformation. In comparison to individual CNTs, the CNT thin films, formed by a random assembly of individual tubes or bundles, show much lower piezoresistive sensitivity. Given the progress made to date in developing CNT ensemble based-piezoresistive sensors, the related piezoresistive mechanism(s) are still not well understood. The crucial step to obtain a better understanding of this issue is to study the effects of CNT structure in the dispersion on the piezoresistivity of CNT ensemble based-piezoresistive sensors. To reach this goal, my Ph.D. research first focuses on establishing the processing-structure-property relationship of SWCNT thin film piezoresistive sensors. The key accomplishment contains: 1) developing the combined preparative ultracentrifuge method (PUM) and dynamic light scattering (DLS) method to quantitatively characterized SWCNT particle size in dispersions under various sonication conditions; 2) designing combined ultrasonication and microfluidization processing protocol for high throughput and large-scale production of high quality SWCNT dispersions; 3) fabricating varied SWCNT thin film piezoresistive sensors through spray coating technique and immersion-drying post-treatment; and 4) investigating the effect of microstructures of SWCNTs on piezoresistivity of SWCNT thin film sensors. This experimental methodology for quantitative and systematic investigation of the processing-structure-property relationships provides a means for the performance optimization of CNT ensemble based piezoresistive sensors. As a start to understand the piezoresistive mechanism, the second focus of my Ph.D. research is studying charge transport behaviors in SWCNT thin films. It was found that the temperature-dependent sheet resistance of SWCNT thin films could be explained by a 3D variable

  8. The dynamic relationship between structural change and CO2 emissions in Malaysia: a cointegrating approach.

    Science.gov (United States)

    Ali, Wajahat; Abdullah, Azrai; Azam, Muhammad

    2017-05-01

    The current study investigates the dynamic relationship between structural changes, real GDP per capita, energy consumption, trade openness, population density, and carbon dioxide (CO 2 ) emissions within the EKC framework over a period 1971-2013. The study used the autoregressive distributed lagged (ARDL) approach to investigate the long-run relationship between the selected variables. The study also employed the dynamic ordinary least squared (DOLS) technique to obtain the robust long-run estimates. Moreover, the causal relationship between the variables is explored using the VECM Granger causality test. Empirical results reveal a negative relationship between structural change and CO 2 emissions in the long run. The results indicate a positive relationship between energy consumption, trade openness, and CO 2 emissions. The study applied the turning point formula of Itkonen (2012) rather than the conventional formula of the turning point. The empirical estimates of the study do not support the presence of the EKC relationship between income and CO 2 emissions. The Granger causality test indicates the presence of long-run bidirectional causality between energy consumption, structural change, and CO 2 emissions in the long run. Economic growth, openness to trade, and population density unidirectionally cause CO 2 emissions. These results suggest that the government should focus more on information-based services rather than energy-intensive manufacturing activities. The feedback relationship between energy consumption and CO 2 emissions suggests that there is an ominous need to refurbish the energy-related policy reforms to ensure the installations of some energy-efficient modern technologies.

  9. New Insights about Enzyme Evolution from Large Scale Studies of Sequence and Structure Relationships*

    Science.gov (United States)

    Brown, Shoshana D.; Babbitt, Patricia C.

    2014-01-01

    Understanding how enzymes have evolved offers clues about their structure-function relationships and mechanisms. Here, we describe evolution of functionally diverse enzyme superfamilies, each representing a large set of sequences that evolved from a common ancestor and that retain conserved features of their structures and active sites. Using several examples, we describe the different structural strategies nature has used to evolve new reaction and substrate specificities in each unique superfamily. The results provide insight about enzyme evolution that is not easily obtained from studies of one or only a few enzymes. PMID:25210038

  10. New insights about enzyme evolution from large scale studies of sequence and structure relationships.

    Science.gov (United States)

    Brown, Shoshana D; Babbitt, Patricia C

    2014-10-31

    Understanding how enzymes have evolved offers clues about their structure-function relationships and mechanisms. Here, we describe evolution of functionally diverse enzyme superfamilies, each representing a large set of sequences that evolved from a common ancestor and that retain conserved features of their structures and active sites. Using several examples, we describe the different structural strategies nature has used to evolve new reaction and substrate specificities in each unique superfamily. The results provide insight about enzyme evolution that is not easily obtained from studies of one or only a few enzymes. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Structural equation modeling assessing relationship between mathematics beliefs, teachers' attitudes and teaching practices among novice teachers in Malaysia

    Science.gov (United States)

    Borhan, Noziati; Zakaria, Effandi

    2017-05-01

    This quantitative study was conducted to investigate the perception level of novice teachers about mathematics belief, teachers' attitude towards mathematics and teaching practices of mathematics in the classroom. In addition, it also aims to identify whether there is a correspondence model with the data obtained and to identify the relationship between the variables of beliefs, attitudes and practices among novice teachers in Malaysia. A total of 263 primary novice teachers throughout the country were involved in this study were selected randomly. Respondents are required to provide a response to the questionnaire of 66 items related to mathematics beliefs, attitudes and practices of the teaching mathematics. There are ten sub-factors which have been established in this instrument for three major constructs using a Likert scale rating of five points. The items of the constructs undergo the exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) procedure involve of unidimensionality test, convergent validity, construct validity and discriminant validity. Descriptive statistics were used to describe the frequency, percentage, the mean and standard deviation for completing some research questions that have been expressed. As for inferential statistical analysis, the researchers used structural equation modeling (SEM) to answer the question of correspondents model and the relationship between these three variables. The results of the study were found that there exist a correspondence measurement and structural model with the data obtained. While the relationship between variable found that mathematics beliefs have a significant influence on teachers' attitudes towards mathematics as well as the relationship between the attitudes with teaching practices. Meanwhile, mathematics belief had no significant relationship with mathematics teaching practices among novice teachers in Malaysia.

  12. An Empirical Examination of the Relationship Between Test Factor Structure and Test Hierarchical Structure.

    Science.gov (United States)

    Bart, William M.; Airasian, Peter W.

    The question of whether test factor structure is indicative of the test item hierarchy was examined. Data from 1,000 subjects on two sets of five bivalued Law School Admission Test items, which were analyzed with latent trait methods of Bock and Lieberman and of Christoffersson in Psychometrika, were analyzed with an ordering-theoretic method to…

  13. Teaching Structure-Property Relationships: Investigating Molecular Structure and Boiling Point

    Science.gov (United States)

    Murphy, Peter M.

    2007-01-01

    A concise, well-organized table of the boiling points of 392 organic compounds has facilitated inquiry-based instruction in multiple scientific principles. Many individual or group learning activities can be derived from the tabulated data of molecular structure and boiling point based on the instructor's education objectives and the students'…

  14. Computational models for structure-hydrophobicity relationships of 4-carboxyl-2,6-dinitrophenyl azo hydroxynaphthalenes.

    Science.gov (United States)

    Idowu, Olakunle S; Adegoke, Olajire A; Idowu, Abiola; Olaniyi, Ajibola A

    2007-01-01

    Some phenyl azo hydroxynaphthalene dyes (e.g., sunset yellow) are certified as approved colorants for food, cosmetics, and drug formulations. The hydrophobicity of 4 newly synthesized azo dyes of the phenyl azo hydroxynaphthalene class was investigated, as a training set, with the goal of developing models for quantitative structure-property relationships (QSPR). Retention behavior of the molecules reversed-phase thin-layer chromatography (RPTLC) was investigated using liquid paraffin-coated silica gel as the stationary phase. Mobile phases consisted of aqueous mixtures of methanol, acetone, and dimethylformamide (DMF). Basic hydrophobicity parameter (Rmw), specific hydrophobic surface area (S), and isocratic chromatographic hydrophobicity index (phio) were computed from the chromatographic data. The hydrophobicity index (Rm) decreased linearly with increasing concentration of organic modifiers. Extrapolated Rmw values obtained by using DMF and acetone differ significantly from the value obtained by using methanol as organic modifier [P dyes and may also play useful roles in computer-assisted molecular discovery of nontoxic azo dyes.

  15. Relationship between the position of upper and lower incisors and the internal structure of symphysis

    International Nuclear Information System (INIS)

    Suzuki, Kayou; Nishide, Masashi; Ishii, Yasumasa; Enomoto, Yutaka; Kawamura, Akira; Kasai, Kazutaka

    2002-01-01

    The aim of this study was to investigate the relationship between the position of the upper and lower incisors and cortical bone thickness and CT value of mandibular symphysis obtained by CT images and cephalograms. The specimens were 24 dry skulls of mordern Japanese males (mean age 29 years) without marked crowding and missing tooth, which had been preserved in the Tokyou University Museum. The data were transferred to a workstation, and CT value and thickness of cortical bone were measured. The dentofacial morphology was investigated with a lateral cephalogram. The results were as follows; The thickness of cortal bone was more thicker in order of basal, lingual and labial cortical bone. The CT value showed the same tendency as cortical bone thickness. Significant correlation coefficients were found between cortical bone thickness and CT value in 30, 60, 90, 120 degree areas. The inclination of upper incisors was negatively related to the CT value in basal and lingual region of symphysis. The inclination of lower incisors was positively related to the CT value in basal and lingual region of symphysis. The interincisor angle was positively related to the CT value in basal region of symphysis. In conclusion, the results of this study suggested that the labio-lingual inclination of the upper and lower incisors was associated with the CT value of basal region of sysphysis. It is suggested that the internal structures of symphysis which relate to the occlusion types of incisors are affected by function of masticatory muscles. (author)

  16. A multilevel cross-lagged structural equation analysis for reciprocal relationship between social capital and health.

    Science.gov (United States)

    Yu, Ge; Sessions, John G; Fu, Yu; Wall, Martin

    2015-10-01

    We investigated the reciprocal relationship between individual social capital and perceived mental and physical health in the UK. Using data from the British Household Panel Survey from 1991 to 2008, we fitted cross-lagged structural equation models that include three indicators of social capital vis. social participation, social network, and loneliness. Given that multiple measurement points (level 1) are nested within individuals (level 2), we also applied a multilevel model to allow for residual variation in the outcomes at the occasion and individual levels. Controlling for gender, age, employment status, educational attainment, marital status, household wealth, and region, our analyses suggest that social participation predicts subsequent change in perceived mental health, and vice versa. However, whilst loneliness is found to be significantly related to perceived mental and physical health, reciprocal causality is not found for perceived mental health. Furthermore, we find evidence for reverse effects with both perceived mental and physical health appearing to be the dominant causal factor with respect to the prospective level of social network. Our findings thus shed further light on the importance of social participation and social inclusion in health promotion and aid the development of more effective public health policies in the UK. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Neurological soft signs and their relationships to neurocognitive functions: a re-visit with the structural equation modeling design.

    Directory of Open Access Journals (Sweden)

    Raymond C K Chan

    Full Text Available BACKGROUND: Neurological soft signs and neurocognitive impairments have long been considered important features of schizophrenia. Previous correlational studies have suggested that there is a significant relationship between neurological soft signs and neurocognitive functions. The purpose of the current study was to examine the underlying relationships between these two distinct constructs with structural equation modeling (SEM. METHODS: 118 patients with schizophrenia and 160 healthy controls were recruited for the current study. The abridged version of the Cambridge Neurological Inventory (CNI and a set of neurocognitive function tests were administered to all participants. SEM was then conducted independently in these two samples to examine the relationships between neurological soft signs and neurocognitive functions. RESULTS: Both the measurement and structural models showed that the models fit well to the data in both patients and healthy controls. The structural equations also showed that there were modest to moderate associations among neurological soft signs, executive attention, verbal memory, and visual memory, while the healthy controls showed more limited associations. CONCLUSIONS: The current findings indicate that motor coordination, sensory integration, and disinhibition contribute to the latent construct of neurological soft signs, whereas the subset of neurocognitive function tests contribute to the latent constructs of executive attention, verbal memory, and visual memory in the present sample. Greater evidence of neurological soft signs is associated with more severe impairment of executive attention and memory functions. Clinical and theoretical implications of the model findings are discussed.

  18. The mediational significance of negative/depressive affect in the relationship of childhood maltreatment and eating disorder features in adolescent psychiatric inpatients.

    Science.gov (United States)

    Hopwood, C J; Ansell, E B; Fehon, D C; Grilo, C M

    2011-03-01

    Childhood maltreatment is a risk factor for eating disorder and negative/depressive affect appears to mediate this relation. However, the specific elements of eating- and body-related psychopathology that are influenced by various forms of childhood maltreatment remain unclear, and investigations among adolescents and men/boys have been limited. This study investigated the mediating role of negative affect/depression across multiple types of childhood maltreatment and eating disorder features in hospitalized adolescent boys and girls. Participants were 148 adolescent psychiatric inpatients who completed an assessment battery including measures of specific forms of childhood maltreatment (sexual, emotional, and physical abuse), negative/depressive affect, and eating disorder features (dietary restriction, binge eating, and body dissatisfaction). Findings suggest that for girls, negative/depressive affect significantly mediates the relationships between childhood maltreatment and eating disorder psychopathology, although effects varied somewhat across types of maltreatment and eating disorder features. Generalization of mediation effects to boys was limited.

  19. Doing the Organizational Tango: Symbiotic Relationship between Formal and Informal Organizational Structures for an Agile Organization

    Directory of Open Access Journals (Sweden)

    Irena Malgorzata Ali

    2016-04-01

    Full Text Available This paper reports on research with a broad objective to examine the relationship between two organizational entities, the formally structured organization and informal organizational structures, in a changing operational environment, more specifically during military deployments. The paper draws on organizational and complexity paradigms; based on empirical evidence obtained through qualitative techniques, it describes mechanisms that enable a symbiotic relationship between these two organizational structures in a complex operational landscape. Substantive findings provide insights into the dynamics of the interactions between these structures and illuminate the relationship between three enabling factors – accountability, responsible autonomy, and command and control arrangements – that need to be considered to fully exploit the strengths inherent in both formal and informal structures. Based on these findings, a model for enhancement of organizational agility in response to changes in a complex operational environment is described. The model is predicated on feedback and mutual adjustment of the organization, institution and individual through sensemaking; it illustrates the dynamic nature of interactions that are required for such a response.

  20. Significance of settling model structures and parameter subsets in modelling WWTPs under wet-weather flow and filamentous bulking conditions.

    Science.gov (United States)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen; Plósz, Benedek Gy

    2014-10-15

    Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of ideal and non-ideal flow (dry and wet weather) and settling (good settling and bulking) boundary conditions on the sensitivity of WWTP model outputs to uncertainties intrinsic to the one-dimensional (1-D) SST model structures and parameters. We identify the critical sources of uncertainty in WWTP models through global sensitivity analysis (GSA) using the Benchmark simulation model No. 1 in combination with first- and second-order 1-D SST models. The results obtained illustrate that the contribution of settling parameters to the total variance of the key WWTP process outputs significantly depends on the influent flow and settling conditions. The magnitude of the impact is found to vary, depending on which type of 1-D SST model is used. Therefore, we identify and recommend potential parameter subsets for WWTP model calibration, and propose optimal choice of 1-D SST models under different flow and settling boundary conditions. Additionally, the hydraulic parameters in the second-order SST model are found significant under dynamic wet-weather flow conditions. These results highlight the importance of developing a more mechanistic based flow-dependent hydraulic sub-model in second-order 1-D SST models in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Computational study of the structure-free radical scavenging relationship of procyanidins.

    Science.gov (United States)

    Mendoza-Wilson, Ana María; Castro-Arredondo, Sergio Ivan; Balandrán-Quintana, René Renato

    2014-10-15

    Procyanidins (PCs) are effective free radical scavengers, however, their antioxidant ability is variable because they have different degrees of polymerisation, are composed by distinct types of subunits and are very susceptible to changes in conformation. In this work the structure-free radical scavenging relationship of monomers, dimers and trimers of PCs was studied through the hydrogen atom transfer (HAT), sequential proton-loss electron-transfer (SPLET) and single electron transfer followed by proton transfer (SET-PT) mechanisms in aqueous phase, employing the Density Functional Theory (DFT) computational method. The structure-free radical scavenging relationship of PCs showed a very similar behaviour in HAT and SET-PT mechanisms, but very different in the SPLET mechanism. The structural factor that showed more effects on the ability of PCs to scavenge free radicals in aqueous phase was the conformation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. The rat intervertebral disk degeneration pain model: relationships between biological and structural alterations and pain.

    Science.gov (United States)

    Kim, Jae-Sung; Kroin, Jeffrey S; Li, Xin; An, Howard S; Buvanendran, Asokumar; Yan, Dongyao; Tuman, Kenneth J; van Wijnen, Andre J; Chen, Di; Im, Hee-Jeong

    2011-01-01

    Degeneration of the interverterbral disk is as a cause of low-back pain is increasing. To gain insight into relationships between biological processes, structural alterations and behavioral pain, we created an animal model in rats. Disk degeneration was induced by removal of the nucleus pulposus (NP) from the lumbar disks (L4/L5 and L5/L6) of Sprague Dawley rats using a 0.5-mm-diameter microsurgical drill. The degree of primary hyperalgesia was assessed by using an algometer to measure pain upon external pressure on injured lumbar disks. Biochemical and histological assessments and radiographs of injured disks were used for evaluation. We investigated therapeutic modulation of chronic pain by administering pharmaceutical drugs in this animal model. After removal of the NP, pressure hyperalgesia developed over the lower back. Nine weeks after surgery we observed damaged or degenerated disks with proteoglycan loss and narrowing of disk height. These biological and structural changes in disks were closely related to the sustained pain hyperalgesia. A high dose of morphine (6.7 mg/kg) resulted in effective pain relief. However, high doses of pregabalin (20 mg/kg), a drug that has been used for treatment of chronic neuropathic pain, as well as the anti-inflammatory drugs celecoxib (50 mg/kg; a selective inhibitor of cyclooxygenase 2 (COX-2)) and ketorolac (20 mg/kg; an inhibitor of COX-1 and COX-2), did not have significant antihyperalgesic effects in our disk injury animal model. Although similarities in gene expression profiles suggest potential overlap in chronic pain pathways linked to disk injury or neuropathy, drug-testing results suggest that pain pathways linked to these two chronic pain conditions are mechanistically distinct. Our findings provide a foundation for future research on new therapeutic interventions that can lead to improvements in the treatment of patients with back pain due to disk degeneration.

  3. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: significance of the inverted-pear glenoid and the humeral engaging Hill-Sachs lesion.

    Science.gov (United States)

    Burkhart, S S; De Beer, J F

    2000-10-01

    Our goal was to analyze the results of 194 consecutive arthroscopic Bankart repairs (performed by 2 surgeons with an identical suture anchor technique) in order to identify specific factors related to recurrence of instability. Case series. We analyzed 194 consecutive arthroscopic Bankart repairs by suture anchor technique performed for traumatic anterior-inferior instability. The average follow-up was 27 months (range, 14 to 79 months). There were 101 contact athletes (96 South African rugby players and 5 American football players). We identified significant bone defects on either the humerus or the glenoid as (1) "inverted-pear" glenoid, in which the normally pear-shaped glenoid had lost enough anterior-inferior bone to assume the shape of an inverted pear; or (2) "engaging" Hill-Sachs lesion of the humerus, in which the orientation of the Hill-Sachs lesion was such that it engaged the anterior glenoid with the shoulder in abduction and external rotation. There were 21 recurrent dislocations and subluxations (14 dislocations, 7 subluxations). Of those 21 shoulders with recurrent instability, 14 had significant bone defects (3 engaging Hill-Sachs and 11 inverted-pear Bankart lesions). For the group of patients without significant bone defects (173 shoulders), there were 7 recurrences (4% recurrence rate). For the group with significant bone defects (21 patients), there were 14 recurrences (67% recurrence rate). For contact athletes without significant bone defects, there was a 6.5% recurrence rate, whereas for contact athletes with significant bone defects, there was an 89% recurrence rate. (1) Arthroscopic Bankart repairs give results equal to open Bankart repairs if there are no significant structural bone deficits (engaging Hill-Sachs or inverted-pear Bankart lesions). (2) Patients with significant bone deficits as defined in this study are not candidates for arthroscopic Bankart repair. (3) Contact athletes without structural bone deficits may be treated by

  4. Novel ventilation design of combining spacer and mesh structure in sports T-shirt significantly improves thermal comfort.

    Science.gov (United States)

    Sun, Chao; Au, Joe Sau-chuen; Fan, Jintu; Zheng, Rong

    2015-05-01

    This paper reports on novel ventilation design in sports T-shirt, which combines spacer and mesh structure, and experimental evidence on the advantages of design in improving thermal comfort. Evaporative resistance (Re) and thermal insulation (Rc) of T-shirts were measured using a sweating thermal manikin under three different air velocities. Moisture permeability index (i(m)) was calculated to compare the different designed T-shirts. The T-shirts of new and conventional designs were also compared by wearer trials, which were comprised of 30 min treadmill running followed by 10 min rest. Skin temperature, skin relative humidity, heart rate, oxygen inhalation and energy expenditure were monitored, and subjective sensations were asked. Results demonstrated that novel T-shirt has 11.1% significant lower im than control sample under windy condition. The novel T-shirt contributes to reduce the variation of skin temperature and relative humidity up to 37% and 32%, as well as decrease 3.3% energy consumption during exercise. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  5. Significant manipulation of output performance of a bridge-structured spin valve magnetoresistance sensor via an electric field

    Science.gov (United States)

    Zhang, Yue; Yan, Baiqian; Ou-Yang, Jun; Wang, Xianghao; Zhu, Benpeng; Chen, Shi; Yang, Xiaofei

    2016-01-01

    Through principles of spin-valve giant magnetoresistance (SV-GMR) effect and its application in magnetic sensors, we have investigated electric-field control of the output performance of a bridge-structured Co/Cu/NiFe/IrMn SV-GMR sensor on a PZN-PT piezoelectric substrate using the micro-magnetic simulation. We centered on the influence of the variation of uniaxial magnetic anisotropy constant (K) of Co on the output of the bridge, and K was manipulated via the stress of Co, which is generated from the strain of a piezoelectric substrate under an electric field. The results indicate that when K varies between 2 × 104 J/m3 and 10 × 104 J/m3, the output performance can be significantly manipulated: The linear range alters from between -330 Oe and 330 Oe to between -650 Oe and 650 Oe, and the sensitivity is tuned by almost 7 times, making it possible to measure magnetic fields with very different ranges. According to the converse piezoelectric effect, we have found that this variation of K can be realized by applying an electric field with the magnitude of about 2-20 kV/cm on a PZN-PT piezoelectric substrate, which is realistic in application. This result means that electric-control of SV-GMR effect has potential application in developing SV-GMR sensors with improved performance.

  6. Intracavitary brachytherapy significantly enhances local control of early T-stage nasopharyngeal carcinoma: the existence of a dose-tumor-control relationship above conventional tumoricidal dose

    International Nuclear Information System (INIS)

    Teo, Peter Man Lung; Leung, Sing Fai; Lee, Wai Yee; Zee, Benny

    2000-01-01

    the chronic radiation complications, with the exception of chronic radiation nasopharyngeal ulceration/necrosis which occurred in 10 patients in Group A and 1 patient in Group B. Headache (n = 4) and foul smell (n = 8) consequential to ulceration/necrosis were mild and manageable by conservative means. A significant dose-tumor-control relationship existed when local failure was studied as a function of the total physical dose or the total biological equivalent dose (linear quadratic equation, α/β = 10) uncorrected for tumor repopulation during the time course of the radiotherapy. Conclusions: Supplementing ERT which delivered tumoricidal dose (uncorrected BED-10 ≥75 Gy), ICT significantly enhanced ultimate local control and avoided the necessity for morbid salvage treatments in early T-stage (T1/T2 nasal infiltration) NPC. The slight increase in chronic radiation ulceration/necrosis after ICT was acceptable with mild and manageable symptoms. Other late complications were not increased. A significant dose-tumor-control relationship exists above the conventional tumoricidal dose level

  7. Structure of Unsteady Partially Premixed Flames and the Existence of State Relationships

    Directory of Open Access Journals (Sweden)

    Suresh K. Aggarwal

    2009-09-01

    essentially similar in the second regime. A more significant difference in the first regime between these flames is the presence of a flow instability that manifests itself through the self-excited oscillations of the 1-g flame and the concomitant flickering of the nonpremixed reaction zone. For VR ≤ 1, as the coflow velocity is increased, the oscillation amplitude decreases and the oscillation frequency increases, both of which are in accord with previous experimental and computational results concerning 1-g jet diffusion flames. The modified conserved scalar approach is found to be effective in characterizing the flame structure and developing state relationships for both steady and unsteady partially premixed flames. This is demonstrated by the fact that the temperature as well as the major and minor species profiles follow similar state relationships in terms of the modified mixture fraction for the 0- and 1-g flames, even though these flames have markedly different spatio-temporal characteristics.

  8. Comparing the Structure-Function Relationship at the Macula With Standard Automated Perimetry and Microperimetry.

    Science.gov (United States)

    Rao, Harsha L; Januwada, Manideepak; Hussain, Raza S M; Pillutla, Lalitha N; Begum, Viquar U; Chaitanya, Aditya; Senthil, Sirisha; Garudadri, Chandra S

    2015-12-01

    To compare the structure-function relationship between ganglion cell-inner plexiform layer (GCIPL) thickness measurements using spectral-domain optical coherence tomography (SDOCT) and visual sensitivities measured using standard automated perimetry (SAP) and microperimetry (MP) at the macula in glaucoma. In a prospective study, 45 control eyes (29 subjects) and 60 glaucoma eyes (45 patients) underwent visual sensitivity estimation at the macula (central 10°) by SAP and MP, and GCIPL thickness measurement at the macula by SDOCT. Structure-function relationships between GCILP thickness and visual sensitivity loss with SAP and MP at various macular sectors were assessed using the Hood and Kardon model. To compare structure-function relationship with SAP and MP, we calculated the number of data points falling outside the 5th and the 95th percentile values of the Hood and Kardon model with each of the perimeters. The number of points falling outside the 5th and 95th percentile values of the Hood and Kardon model ranged from 28 (superior sector) to 48 (inferonasal sector) with SAP and 33 (superior sector) to 49 (inferonasal sector) with MP. The difference in the number of points falling outside the 5th and 95th percentile values with SAP and MP was statistically insignificant (P > 0.05, χ(2) test) for all the sectors. Visual sensitivity measurements of both SAP and MP demonstrated a similar relationship with the GCIPL measurements of SDOCT at the macula in glaucoma.

  9. An examination of a reciprocal relationship between network governance and network structure

    DEFF Research Database (Denmark)

    Bergenholtz, Carsten; Goduscheit, René Chester

    The present article examines the network structure and governance of inter-organisational innovation networks. Network governance refers to the issue of how to manage and coordinate the relational activities and processes in the network while research on network structure deals with the overall...... structural relations between the actors in the network. These streams of research do contain references to each other but mostly rely on a static conception of the relationship between network structure and the applied network governance. The paper is based on a primarily qualitative case study of a loosely...... coupled Danish inter-organisational innovation network. The proposition is that a reciprocal relation between network governance and network structure can be identified....

  10. Calculation of Quantitative Structure-Activity Relationship Descriptors of Artemisinin Derivatives

    Directory of Open Access Journals (Sweden)

    Jambalsuren Bayarmaa

    2008-06-01

    Full Text Available Quantitative structure-activity relationships are based on the construction of predictive models using a set of known molecules and associated activity value. This accurate methodology, developed with adequate mathematical and computational tools, leads to a faster, cheaper and more comprehensive design of new products, reducing the experimental synthesis and testing on animals. Preparation of the QSAR models of artemisinin derivatives was carried out by the genetic function algorithm (GFA method for 91 molecules. The results show some relationships to the observed antimalarial activities of the artemisinin derivatives. The most statistically signi fi cant regression equation obtained from the fi nal GFA relates to two molecular descriptors.

  11. Cenozoic geology of the Yolomécatl-Tlaxiaco area, Northwestern Oaxaca, Southeastern Mexico: Stratigraphy, structure and regional significance

    Science.gov (United States)

    Ferrusquía-Villafranca, Ismael; Ruiz-González, José E.; Torres-Hernández, José Ramón; Anderson, Thomas H.; Urrutia-Fucugauchi, Jaime; Martínez-Hernández, Enrique; García-Villegas, Felipe

    2016-12-01

    The Yolomécatl-Tlaxiaco Area, lies in the rugged Sierra Madre del Sur (SMS) of northwestern Oaxaca (YOTLA), southeastern Mexico. Within the area Cenozoic units unconformably overlie metamorphic, clastic and carbonate rock units of Late Paleozoic to Cretaceous ages as well as the Mixteco/Oaxaca Terrane boundary. The Cenozoic sequence, emphasized herein, includes from botton to top: (1) basal, calcilithitic Early Tertiary Tamazulapam Conglomerate, (2) andesitic lava flows of Nduayaco "Group," (3-4) Epiclastic/pyroclastic strata composing Yolomécatl Formation (∼40.3 ± 1.0 Ma), and Tayata Pyroepiclastics (5) Early Oligocene (∼32.9 Ma), felsic, pyroclastic Nundichi "Group," (6) Late Oligocene (∼27.7 ± 0.7 Ma) andesitic lava flows of Nicananduta "Group" containing intercalations of unit (7) ?Chilapa Formation (largely lacustrine). Quaternary deposits unconformably overlie the sequence. The structural record includes NNW-SSE folds in the Mesozoic units, and one in Tayata Pyroepiclastics, as well as numerous fractures/faults of diverse types, whose pattern seems to roughly define four geographic/structural domains, NW, SW, S, and E. The Tertiary sequence records four magmatic and six deformational events: Pre-Late Eocene Extension accommodated by the Tamazulapam fault, along which magma of the Nduayaco "Group" moved upward. The next episode is the earliest Late Eocene extension recorded by the Yucuxaco-Santa Cruz Tayata fault was followed by accumulation of Yolomécatl Formation, Tayata Pyroepiclastics, and synsedimentary emplacement of tuff sheets at ∼40.3 ± 1.0 Ma. After this date, left lateral transpression emplaced a Teposcolula Limestone block over Nduayaco "Group" and ?Yolomécatl Formation, whereas the Tayata Pyroepiclastics was folded into an open anticline. Movement along the Yucuxaco-Santa Cruz Tayayata fault suite influenced accumulation of the Nundichi "Group" strata ca. ∼32.9 Ma. Subsequent ENE-WSW extension affected the Nundichi "Group," partly

  12. Factor Structure of the Chinese Version of the Parent Adult-Child Relationship Questionnaire

    Directory of Open Access Journals (Sweden)

    Daoyang Wang

    2018-03-01

    Full Text Available The Parent Adult-Child Relationship Questionnaire (PACQ included two identical versions of the 13-item scale, which were administered to each subject, one which referred to “relationship with mother” and the other to “relationship with father.” The PACQ, originally in English, is a self-report measure of the filial relationship. The present study aimed to develop a Chinese version of the PACQ and use it to explore Chinese parent adult-child relationships. A total of 454 Chinese adult-children completed the Chinese version of the PACQ. The structure of the questionnaire was analyzed using exploratory factor analysis (EFA and confirmatory factor analysis (CFA. We found that the Cronbach's α was 0.66–0.88 for fathers and 0.76–0.91 for mothers, which demonstrates high internal consistency reliabilities of the Chinese version of the PACQ. The Chinese version of the PACQ for father had similar constructs similar to with those of the original English version. However, a new factor for mothers, “attachment,” was derived from the original English version. The results suggested that the Chinese version of PACQ is a valid and reliable measure of relationship quality between Chinese adult-children and their parents.

  13. Study of relationship between the organizational structure and market orientation from the viewpoint of nurse managers.

    Science.gov (United States)

    Bahadori, Mohammadkarim; Yaghoubi, Maryam; Javadi, Marzieh; Rahimi, Zahreh Agha

    2015-01-01

    Considering globalization of health care and quality improvement trend to respond to competition and customer orientation, attention to organizational structure and its relationship with market orientation is essential. Therefore, this study reviews the relationship between organizational structure and market orientation in selected hospitals of Isfahan (Iran). This study was a descriptive survey. The study population comprised nurse managers from selected hospitals (n = 80). Data collection tools were two questionnaires (market orientation questionnaire and organizational structure) that the validity and reliability were confirmed (r = 0.83 for market orientation questionnaire and r = 0.87 for organizational structure). SPSS (Ver. 16) software was used for the analyses. The mean score of organizational structure was 65.4 (11.2) and total mean of market orientation was 51.14 (17.6). All aspects of the organizational structure (Organization Centralization, Formalization in Organization, and Organization Complication) and market orientation (responding to competition, accountability, customer satisfaction, intelligent organization)-except by responding to clients with Formalization in Organization-as well as all aspects of the Systemic attitude (the system of internal coordination and communication systems_ and market orientation (responding to competition, accountability, customer satisfaction, intelligent organization), there was a meaningful relationship (P organizational structure and can lead managers' view to the analysis and recognizing elements of success and achievement to goals. With increasing competition in markets, globalization of health services, and presence in international markets and more attention to patients' satisfaction, hospitals need to understand and use of market orientation in order to promote quality and services in the health care system.

  14. Comparing Effect of 'Summarizing', 'Question-Answer Relationship', and 'Syntactic Structure Identification' on the Reading Comprehension of Iranian EFL students

    Directory of Open Access Journals (Sweden)

    Fatemeh Hemmati

    2013-01-01

    Full Text Available This study aimed at comparing the effects of 'question-answer relationship strategy', 'summarizing', and 'syntactic structure identification training'on the reading comprehension of Iranian EFL learners. The participants were sixty (34 women and 26 men intermediate students who answered an English reading comprehension test consisting of three reading passages as the pretest. During the treatment, the students in the first group were supposed to summarize the passages. The subjects in the second group familiarized with the syntactic structure identification strategy and the ones in the third group were taught the question-answer relationship strategy. At the end of the treatment, an English reading comprehension test similar to the pretest was administered to the groups as a posttest. The results suggested that there is statistically significant difference between the reading comprehension abilities of the three classes. Furthermore the use of QAR strategy led to better comprehension of reading texts with syntactic structure training and summarizing between which there was no significant difference.

  15. On the relationship between residue structural environment and sequence conservation in proteins.

    Science.gov (United States)

    Liu, Jen-Wei; Lin, Jau-Ji; Cheng, Chih-Wen; Lin, Yu-Feng; Hwang, Jenn-Kang; Huang, Tsun-Tsao

    2017-09-01

    Residues that are crucial to protein function or structure are usually evolutionarily conserved. To identify the important residues in protein, sequence conservation is estimated, and current methods rely upon the unbiased collection of homologous sequences. Surprisingly, our previous studies have shown that the sequence conservation is closely correlated with the weighted contact number (WCN), a measure of packing density for residue's structural environment, calculated only based on the C α positions of a protein structure. Moreover, studies have shown that sequence conservation is correlated with environment-related structural properties calculated based on different protein substructures, such as a protein's all atoms, backbone atoms, side-chain atoms, or side-chain centroid. To know whether the C α atomic positions are adequate to show the relationship between residue environment and sequence conservation or not, here we compared C α atoms with other substructures in their contributions to the sequence conservation. Our results show that C α positions are substantially equivalent to the other substructures in calculations of various measures of residue environment. As a result, the overlapping contributions between C α atoms and the other substructures are high, yielding similar structure-conservation relationship. Take the WCN as an example, the average overlapping contribution to sequence conservation is 87% between C α and all-atom substructures. These results indicate that only C α atoms of a protein structure could reflect sequence conservation at the residue level. © 2017 Wiley Periodicals, Inc.

  16. Significant manipulation of output performance of a bridge-structured spin valve magnetoresistance sensor via an electric field

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yue; Yan, Baiqian; Ou-Yang, Jun; Zhu, Benpeng; Chen, Shi; Yang, Xiaofei, E-mail: hust-yangxiaofei@163.com [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang, Xianghao [School of Information Engineering, Wuhan University of Technology, Wuhan 430070 (China)

    2016-01-28

    Through principles of spin-valve giant magnetoresistance (SV-GMR) effect and its application in magnetic sensors, we have investigated electric-field control of the output performance of a bridge-structured Co/Cu/NiFe/IrMn SV-GMR sensor on a PZN-PT piezoelectric substrate using the micro-magnetic simulation. We centered on the influence of the variation of uniaxial magnetic anisotropy constant (K) of Co on the output of the bridge, and K was manipulated via the stress of Co, which is generated from the strain of a piezoelectric substrate under an electric field. The results indicate that when K varies between 2 × 10{sup 4 }J/m{sup 3} and 10 × 10{sup 4 }J/m{sup 3}, the output performance can be significantly manipulated: The linear range alters from between −330 Oe and 330 Oe to between −650 Oe and 650 Oe, and the sensitivity is tuned by almost 7 times, making it possible to measure magnetic fields with very different ranges. According to the converse piezoelectric effect, we have found that this variation of K can be realized by applying an electric field with the magnitude of about 2–20 kV/cm on a PZN-PT piezoelectric substrate, which is realistic in application. This result means that electric-control of SV-GMR effect has potential application in developing SV-GMR sensors with improved performance.

  17. Significant manipulation of output performance of a bridge-structured spin valve magnetoresistance sensor via an electric field

    International Nuclear Information System (INIS)

    Zhang, Yue; Yan, Baiqian; Ou-Yang, Jun; Zhu, Benpeng; Chen, Shi; Yang, Xiaofei; Wang, Xianghao

    2016-01-01

    Through principles of spin-valve giant magnetoresistance (SV-GMR) effect and its application in magnetic sensors, we have investigated electric-field control of the output performance of a bridge-structured Co/Cu/NiFe/IrMn SV-GMR sensor on a PZN-PT piezoelectric substrate using the micro-magnetic simulation. We centered on the influence of the variation of uniaxial magnetic anisotropy constant (K) of Co on the output of the bridge, and K was manipulated via the stress of Co, which is generated from the strain of a piezoelectric substrate under an electric field. The results indicate that when K varies between 2 × 10 4  J/m 3 and 10 × 10 4  J/m 3 , the output performance can be significantly manipulated: The linear range alters from between −330 Oe and 330 Oe to between −650 Oe and 650 Oe, and the sensitivity is tuned by almost 7 times, making it possible to measure magnetic fields with very different ranges. According to the converse piezoelectric effect, we have found that this variation of K can be realized by applying an electric field with the magnitude of about 2–20 kV/cm on a PZN-PT piezoelectric substrate, which is realistic in application. This result means that electric-control of SV-GMR effect has potential application in developing SV-GMR sensors with improved performance

  18. Structural relationships among attachment insecurity, alexithymia, and body esteem in women with eating disorders.

    Science.gov (United States)

    Keating, Leah; Tasca, Giorgio A; Hill, Robert

    2013-08-01

    Patients with eating disorders tend to experience low levels of body esteem. To assess the psychosocial processes that may predict low body esteem in these individuals, we assessed the structural interrelations among attachment anxiety, attachment avoidance, alexithymia, and body esteem in a cross-sectional sample of patients with eating disorders. We tested a model in which alexithymia mediates the relationship between attachment insecurity and body esteem. Participants were 300 women with anorexia nervosa (n = 109), bulimia nervosa (n = 130), and eating disorders not otherwise specified (n = 61) who completed pretreatment self-report questionnaires at intake for a day hospital treatment program. We found a direct and negative relationship between attachment anxiety and body esteem. Additionally, attachment avoidance had an indirect negative relationship to body esteem through alexithymia. These results indicate that therapists may attend to attachment insecurity and affective regulation strategies when addressing body image issues in patients with eating disorders. © 2013 Elsevier Ltd. All rights reserved.

  19. Process-Structure-Property Relationship in Magnesium-Based Biodegradable Alloy for Biomedical Applications

    Science.gov (United States)

    Trivedi, Pramanshu

    Magnesium alloys are considered to be the next generation of biomaterials because of their ability to degrade in the physiological environment. We elucidate here the impact of multiaxial forging of Mg-2Zn-2Gd alloy on grain refinement to sub-micron regime and relate the structure to mechanical properties and biological functionality. As-cast and annealed samples were multiaxial forged (MAF) for a total number of two passes with a true strain of 2/pass. Considering that the microstructure governs the biological response of materials, we studied the constituents of the microstructure in conjunction with the mechanical behavior. The antimicrobial behavior in a Mg-2Zn-2Gd alloy with different grain size in the range of 44 microm to 710 nm was studied by seeding. Surface energy and contact angle measurements using goniometer and wettability were assessed with water, SBF, n-Hexane, and DMEM. The structure-property relationship in Mg-2Zn-2Gd alloy to maintaining mechanical integrity during degradation was studied by seeding Escherichia coli ( E. coli). Furthermore, we studied the effect of degradation behavior in the presence and absence of cells. This was followed by the study of bioactivity in terms of phases present on the surface and degradation products in simulated body fluid (SBF). Magnesium coated with apatite using a biomimetic approach were placed in a 24-well culture plate with alpha-MEM media and the degradation behavior was studied in the absence and presence of cells (seeding density: 10,000 cells/cm2). The change in pH was monitored at regular intervals. Cell attachment was studied by seeding the cells for 4h and cell viability was studied by seeding the cells for up to 1, 3, and 7 days. The study underscores that the fine-grained alloys exhibited superior mechanical properties, antimicrobial resistance, and cell attachment. The degradation rate was also least for fine-grained alloy. The higher surface energy of ultrafine-grained Mg-2Zn-2Gd alloy led to the

  20. Investigations on the structure – Property relationships of electron beam welded Inconel 625 and UNS 32205

    International Nuclear Information System (INIS)

    Devendranath Ramkumar, K.; Sridhar, R.; Periwal, Saurabh; Oza, Smitkumar; Saxena, Vimal; Hidad, Preyas; Arivazhagan, N.

    2015-01-01

    Highlights: • Joining of dissimilar metals of Inconel 625 and UNS S32205 using electron beam welding. • Detailed structure – property relationship of dissimilar welds. • Improved metallurgical and tensile properties from the EB welding. - Abstract: The metallurgical and mechanical properties of electron beam welded Ni based superalloy Inconel 625 and UNS S32205 duplex stainless steel plates have been investigated in the present study. Interface microstructure studies divulged the absence of any grain coarsening effects or the formation of any secondary phases at the heat affected zone (HAZ) of the electron beam (EB) weldments. Tensile studies showed that the fracture occurred at the weld zone in all the trials and the average weld strength was reported to be 850 MPa. Segregation of Mo rich phases was witnessed at the inter-dendritic arms of the fusion zone. The study recommended the use of EB welding for joining these dissimilar metals by providing detailed structure – property relationships

  1. First-Principles Study of Structure Property Relationships of Monolayer (Hydroxy)Oxide-Metal Bifunctional Electrocatalysts

    DEFF Research Database (Denmark)

    Zeng, Zhenhua; Kubal, Joseph; Greeley, Jeffrey Philip

    2015-01-01

    step towards accurate identification and prediction of a variety of oxide/electrode interfacial structure-properties relationships, but also provides the foundation for rational design and control of ‘targeted active phases’ at catalytic interfaces. The successful design of bifunctional......In the present study, on the basis of detailed density functional theory (DFT) calculations, and using Ni hydroxy(oxide) films on Pt(111) and Au(111) electrodes as model systems, we describe a detailed structural and electrocatalytic analysis of hydrogen evolution (HER) at three-phase boundaries...... under alkaline electrochemical conditions. We demonstrate that the structure and oxidation state of the films can be systematically tuned by changing the applied electrode potential and/or the nature of substrates. Structural features determined from the theoretical calculations provide a wealth...

  2. Polyploidy and the relationship between leaf structure and function: implications for correlated evolution of anatomy, morphology, and physiology in Brassica.

    Science.gov (United States)

    Baker, Robert L; Yarkhunova, Yulia; Vidal, Katherine; Ewers, Brent E; Weinig, Cynthia

    2017-01-05

    Polyploidy is well studied from a genetic and genomic perspective, but the morphological, anatomical, and physiological consequences of polyploidy remain relatively uncharacterized. Whether these potential changes bear on functional integration or are idiosyncratic remains an open question. Repeated allotetraploid events and multiple genomic combinations as well as overlapping targets of artificial selection make the Brassica triangle an excellent system for exploring variation in the connection between plant structure (anatomy and morphology) and function (physiology). We examine phenotypic integration among structural aspects of leaves including external morphology and internal anatomy with leaf-level physiology among several species of Brassica. We compare diploid and allotetraploid species to ascertain patterns of phenotypic correlations among structural and functional traits and test the hypothesis that allotetraploidy results in trait disintegration allowing for transgressive phenotypes and additional evolutionary and crop improvement potential. Among six Brassica species, we found significant effects of species and ploidy level for morphological, anatomical and physiological traits. We identified three suites of intercorrelated traits in both diploid parents and allotetraploids: Morphological traits (such as leaf area and perimeter) anatomic traits (including ab- and ad- axial epidermis) and aspects of physiology. In general, there were more correlations between structural and functional traits for allotetraploid hybrids than diploid parents. Parents and hybrids did not have any significant structure-function correlations in common. Of particular note, there were no significant correlations between morphological structure and physiological function in the diploid parents. Increased phenotypic integration in the allotetraploid hybrids may be due, in part, to increased trait ranges or simply different structure-function relationships. Genomic and chromosomal

  3. Structure-Activity Relationships on the Molecular Descriptors Family Project at the End

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2007-12-01

    Full Text Available Molecular Descriptors Family (MDF on the Structure-Activity Relationships (SAR, a promising approach in investigation and quantification of the link between 2D and 3D structural information and the activity, and its potential in the analysis of the biological active compounds is summarized. The approach, attempts to correlate molecular descriptors family generated and calculated on a set of biological active compounds with their observed activity. The estimation as well as prediction abilities of the approach are presented. The obtained MDF SAR models can be used to predict the biological activity of unknown substrates in a series of compounds.

  4. Overnight weight loss: relationship with sleep structure and heart rate variability

    OpenAIRE

    Walter Moraes; Dalva Poyares; Christian Guilleminault; Agostinho Rosa; Marco Tulio Mello; Adriana Rueda; Sergio Tufik

    2008-01-01

    Background: Weight loss can be caused by a loss of body mass due to metabolism and by water loss as unsensible water loss, sweating, or excretion in feces and urine. Although weight loss during sleep is a well-known phenomenon, it has not yet been studied in relation to sleep structure or autonomic tonus during sleep. Our study is proposed to be a first step in assessing the relationship between overnight weight loss, sleep structure, and HRV (heart rate variability) parameters.Methods: Twent...

  5. Modifiers in rhodium catalysts for carbon monoxide hydrogenation: Structure-activity relationships

    Energy Technology Data Exchange (ETDEWEB)

    Bhore, N. A.

    1989-05-01

    This report is aimed at identifying interesting modified rhodium systems and elucidating structure-activity relationships in these systems with the overall goal of understanding the scientific issues in the catalytic conversion of syngas to oxygenates. Specific additives (sodium and molybdenum) are selected based on the scoping experiments. The effect of the additives on supported rhodium catalysts is then investigated. Throughout the investigation, experiments and analysis were performed on real systems instead of ideal systems. 374 refs., 82 figs., 57 tabs.

  6. Computational modeling of the structure-function relationship in human placental terminal villi.

    OpenAIRE

    Plitman, Mayo R; Olsthoorn, Jason; Charnock-Jones, David Stephen; Burton, Graham James; Oyen, Michelle Lynn

    2016-01-01

    Placental oxygen transport takes place at the final branches of the villous tree and is dictated by the relative arrangement of the maternal and fetal circulations. Modeling techniques have failed to accurately assess the structure-function relationship in the terminal villi due to the geometrical complexity. Three-dimensional blood flow and oxygen transport was modeled in four terminal villi reconstructed from confocal image stacks. The blood flow was analyzed along the center lines of capil...

  7. A multilevel cross-lagged structural equation analysis for reciprocal relationship between social capital and health

    OpenAIRE

    Sessions, John; Yu, Ge; Fu, Yu; Wall, Matin

    2015-01-01

    We investigated the reciprocal relationship between individual social capital and perceived mental and physical health in the UK. Using data from the British Household Panel Survey from 1991 to 2008, we fitted cross-lagged structural equation models that include three indicators of social capital vis. social participation, social network, and loneliness. Given that multiple measurement points (level 1) are nested within individuals (level 2), we also applied a multilevel model to allow for re...

  8. Structure-activity relationships of nucleoside analogues for inhibition of tick-borne encephalitis virus

    Czech Academy of Sciences Publication Activity Database

    Eyer, L.; Šmídková, Markéta; Nencka, Radim; Neča, J.; Kastl, T.; Palus, Martin; De Clercq, E.; Růžek, Daniel

    2016-01-01

    Roč. 133, Sep (2016), s. 119-129 ISSN 0166-3542 R&D Projects: GA MZd(CZ) NV16-34238A; GA ČR(CZ) GA16-20054S Institutional support: RVO:61388963 ; RVO:60077344 Keywords : structure-activity relationship * tick-borne encephalitis * nucleoside inhibitor * antiviral activity * cytotoxicity Subject RIV: CC - Organic Chemistry; EE - Microbiology, Virology (BC-A) Impact factor: 4.271, year: 2016

  9. Spatio-Temporal Story Mapping Animation Based On Structured Causal Relationships Of Historical Events

    Science.gov (United States)

    Inoue, Y.; Tsuruoka, K.; Arikawa, M.

    2014-04-01

    In this paper, we proposed a user interface that displays visual animations on geographic maps and timelines for depicting historical stories by representing causal relationships among events for time series. We have been developing an experimental software system for the spatial-temporal visualization of historical stories for tablet computers. Our proposed system makes people effectively learn historical stories using visual animations based on hierarchical structures of different scale timelines and maps.

  10. Efficiently mapping structure-property relationships of gas adsorption in porous materials: application to Xe adsorption.

    Science.gov (United States)

    Kaija, A R; Wilmer, C E

    2017-09-08

    Designing better porous materials for gas storage or separations applications frequently leverages known structure-property relationships. Reliable structure-property relationships, however, only reveal themselves when adsorption data on many porous materials are aggregated and compared. Gathering enough data experimentally is prohibitively time consuming, and even approaches based on large-scale computer simulations face challenges. Brute force computational screening approaches that do not efficiently sample the space of porous materials may be ineffective when the number of possible materials is too large. Here we describe a general and efficient computational method for mapping structure-property spaces of porous materials that can be useful for adsorption related applications. We describe an algorithm that generates random porous "pseudomaterials", for which we calculate structural characteristics (e.g., surface area, pore size and void fraction) and also gas adsorption properties via molecular simulations. Here we chose to focus on void fraction and Xe adsorption at 1 bar, 5 bar, and 10 bar. The algorithm then identifies pseudomaterials with rare combinations of void fraction and Xe adsorption and mutates them to generate new pseudomaterials, thereby selectively adding data only to those parts of the structure-property map that are the least explored. Use of this method can help guide the design of new porous materials for gas storage and separations applications in the future.

  11. Biosynthesis and structure-activity relationships of the lipid a family of glycolipids.

    Science.gov (United States)

    Xiao, Xirui; Sankaranarayanan, Karthik; Khosla, Chaitan

    2017-10-01

    Lipopolysaccharide (LPS), a glycolipid found in the outer membrane of Gram-negative bacteria, is a potent elicitor of innate immune responses in mammals. A typical LPS molecule is composed of three different structural domains: a polysaccharide called the O-antigen, a core oligosaccharide, and Lipid A. Lipid A is the amphipathic glycolipid moiety of LPS. It stimulates the immune system by tightly binding to Toll-like receptor 4. More recently, Lipid A has also been shown to activate intracellular caspase-4 and caspase-5. An impressive diversity is observed in Lipid A structures from different Gram-negative bacteria, and it is well established that subtle changes in chemical structure can result in dramatically different immune activities. For example, Lipid A from Escherichia coli is highly toxic to humans, whereas a biosynthetic precursor called Lipid IV A blocks this toxic activity, and monophosphoryl Lipid A from Salmonella minnesota is a vaccine adjuvant. Thus, an understanding of structure-activity relationships in this glycolipid family could be used to design useful immunomodulatory agents. Here we review the biosynthesis, modification, and structure-activity relationships of Lipid A. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Impact of the keystone species, the Eurasian beaver (Castor fiber), on habitat structure and its significance to mammals

    OpenAIRE

    Samas, Arūnas

    2016-01-01

    Eurasian beaver (Castor fiber), the representative of the family Castoridae, which includes two living species of the genus Castor. Beavers are the keystone species, also deservedly known as the ecosystem engineer for the ability to create new habitats and to change the existing landscape. Biology of the Eurasian beaver is well studied, but still, there is a lack of knowledge about the ecology of the species - the relationship with the surrounding environment and biota. These studies were car...

  13. The roles of host evolutionary relationships (genus: Nasonia) and development in structuring microbial communities.

    Science.gov (United States)

    Brucker, Robert M; Bordenstein, Seth R

    2012-02-01

    The comparative structure of bacterial communities among closely related host species remains relatively unexplored. For instance, as speciation events progress from incipient to complete stages, does divergence in the composition of the species' microbial communities parallel the divergence of host nuclear genes? To address this question, we used the recently diverged species of the parasitoid wasp genus Nasonia to test whether the evolutionary relationships of their bacterial microbiotas recapitulate the Nasonia phylogenetic history. We also assessed microbial diversity in Nasonia at different stages of development to determine the role that host age plays in microbiota structure. The results indicate that all three species of Nasonia share simple larval microbiotas dominated by the γ-proteobacteria class; however, bacterial species diversity increases as Nasonia develop into pupae and adults. Finally, under identical environmental conditions, the relationships of the microbial communities reflect the phylogeny of the Nasonia host species at multiple developmental stages, which suggests that the structure of an animal's microbial community is closely allied with divergence of host genes. These findings highlight the importance of host evolutionary relationships on microbiota composition and have broad implications for future studies of microbial symbiosis and animal speciation. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  14. Relationships between structural social capital, knowledge identification capability and external knowledge acquisition

    Directory of Open Access Journals (Sweden)

    Beatriz Ortiz

    2017-07-01

    Full Text Available Purpose - The purpose of this paper is to analyze the mediating effect of the identification of valuable external knowledge on the relationship between the development of inter-organizational ties (structural social capital and the acquisition of external knowledge. Design/methodology/approach - Using a sample of 87 firms from Spanish biotechnology and pharmaceutics industries, the authors have tested the proposed mediation hypothesis by applying the partial least squares technique to a structural equations model. Findings - The study results show that those firms with stronger, more frequent and closer inter-relationships are able to increase the amount of intentionally acquired knowledge, partly due to the greater level of development of their knowledge identification capability. Thus, firms with a higher capability to recognize the value of the knowledge embedded in their inter-organizational networks will be more likely to design better strategies to acquire and integrate such knowledge into their current knowledge bases for either present or future use. Originality/value - This research contributes to knowledge management and social capital literature by means of the study of two key determinants of knowledge acquisition – structural social capital and knowledge identification capability – and the explanation of their relationships of mutual influence. The paper thus tries to fill this literature gap and connects the relational perspective of social capital with the knowledge-based view from a strategic point of view.

  15. A structural equation model of patient-healthcare provider relationships and HIV-infected patient outcomes in Chinese populations.

    Science.gov (United States)

    Chen, Wei-Ti; Shiu, Chengshi; Yang, Joyce P; Chuang, Peing; Zhang, Lin; Bao, Meijuan; Lu, Hongzhou

    2018-03-01

    Obtaining maximum antiretroviral therapy (ART) adherence is critical for maintaining a high CD4 count and strong immune function in PLWHA. Key factors for achieving optimum adherence include good medication self-efficacy, decreased medication-taking difficulties, and positive patient-healthcare provider (HCP) relationships. Limited studies have analyzed the correlation of these factors and ART adherence in Chinese population. In this paper, structural equation modeling was performed to assess the proposed model of relations between patient-HCP relationships and adherence. Audio Computer-Assisted Self-Interview (ACASI) software was used to collect data on ART adherence and patient variables among 227 PLWHA in Shanghai and Taipei. Participants completed a one-time 60-minute ACASI survey that consisted of standardized measures to assess demographics, recent CD4 counts, self-efficacy, patient-HCP relationship, adherence, and medication-taking difficulties. The data shown the relationship between patient-HCP relationships and adherence was significantly consistent with mediation by medication self-efficacy. However, patient-HCP interaction did not directly influence medication-taking difficulties, and medication-taking difficulties did not significantly affect CD4 counts. Furthermore, patient-HCP interactions did not directly impact CD4 counts; rather, the relation was consistent with mediation (by either better medication self-efficacy or better adherence) or by improved adherence alone. Future interventions should be designed to enhance self-management and provide better patient-HCP communication. This improved communication will enhance medication self-efficacy and decrease medication-taking difficulties. This in turn will improve medication adherence and immune function among PLWHA.

  16. A Quantitative Structure-Property Relationship (QSPR Study of Aliphatic Alcohols by the Method of Dividing the Molecular Structure into Substructure

    Directory of Open Access Journals (Sweden)

    Bin Cheng

    2011-04-01

    Full Text Available A quantitative structure–property relationship (QSPR analysis of aliphatic alcohols is presented. Four physicochemical properties were studied: boiling point (BP, n-octanol–water partition coefficient (lg POW, water solubility (lg W and the chromatographic retention indices (RI on different polar stationary phases. In order to investigate the quantitative structure–property relationship of aliphatic alcohols, the molecular structure ROH is divided into two parts, R and OH to generate structural parameter. It was proposed that the property is affected by three main factors for aliphatic alcohols, alkyl group R, substituted group OH, and interaction between R and OH. On the basis of the polarizability effect index (PEI, previously developed by Cao, the novel molecular polarizability effect index (MPEI combined with odd-even index (OEI, the sum eigenvalues of bond-connecting matrix (SX1CH previously developed in our team, were used to predict the property of aliphatic alcohols. The sets of molecular descriptors were derived directly from the structure of the compounds based on graph theory. QSPR models were generated using only calculated descriptors and multiple linear regression techniques. These QSPR models showed high values of multiple correlation coefficient (R > 0.99 and Fisher-ratio statistics. The leave-one-out cross-validation demonstrated the final models to be statistically significant and reliable.

  17. QUANTITAVE STRUCTURE-ACTIVITY RELATIONSHIP ANALYSIS (QSAR OF ANTIMALARIAL 1,10-PHENANTHROLINE DERIVATIVES COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Ruslin Hadanu

    2010-06-01

    Full Text Available Quantitative Electronic Structure-Activity Relationship (QSAR analysis of a series of 1,10-phenanthroline derivatives as antiplasmodial compounds have been conducted using atomic net charges (q, dipole moment (μ ELUMO, EHOMO, polarizability (α and log P as the descriptors. The descriptors were obtained from computational chemistry method using semi-empirical PM3. Antiplasmodial activities were taken as the activity of the drugs  against  chloroquine-resistant Plasmodium falciparum FCR3 strain and are presented as the value of ln (1/IC50 where IC50 is an effective concentration inhibiting 50% of the parasite growth. The best model of QSAR model was determine by multiple linear regression method and giving equation of QSAR: ln 1/IC50  =  3.732 + (5.098 qC5 + (7.051 qC7 + (36.696 qC9 + (41.467 qC11 -(135.497 qC12 + (0.332 μ -                    (0.170 α + (0.757 log P. The equation was significant on the 95% level with statistical parameters: n=16; r=0.987; r2= 0.975; SE=0.317;  Fcalc/Ftable = 15.337 and gave the PRESS=0.707. Its means that there were only a relatively few deviations between the experimental and theoretical data of antimalarial activity.   Keywords: QSAR, antimalarial, semi-empirical method, 1,10-phenanthroline.

  18. Relationships between chemical structure, mechanical properties and materials processing in nanopatterned organosilicate fins

    Directory of Open Access Journals (Sweden)

    Gheorghe Stan

    2017-04-01

    Full Text Available The exploitation of nanoscale size effects to create new nanostructured materials necessitates the development of an understanding of relationships between molecular structure, physical properties and material processing at the nanoscale. Numerous metrologies capable of thermal, mechanical, and electrical characterization at the nanoscale have been demonstrated over the past two decades. However, the ability to perform nanoscale molecular/chemical structure characterization has only been recently demonstrated with the advent of atomic-force-microscopy-based infrared spectroscopy (AFM-IR and related techniques. Therefore, we have combined measurements of chemical structures with AFM-IR and of mechanical properties with contact resonance AFM (CR-AFM to investigate the fabrication of 20–500 nm wide fin structures in a nanoporous organosilicate material. We show that by combining these two techniques, one can clearly observe variations of chemical structure and mechanical properties that correlate with the fabrication process and the feature size of the organosilicate fins. Specifically, we have observed an inverse correlation between the concentration of terminal organic groups and the stiffness of nanopatterned organosilicate fins. The selective removal of the organic component during etching results in a stiffness increase and reinsertion via chemical silylation results in a stiffness decrease. Examination of this effect as a function of fin width indicates that the loss of terminal organic groups and stiffness increase occur primarily at the exposed surfaces of the fins over a length scale of 10–20 nm. While the observed structure–property relationships are specific to organosilicates, we believe the combined demonstration of AFM-IR with CR-AFM should pave the way for a similar nanoscale characterization of other materials where the understanding of such relationships is essential.

  19. Relationship among visual field, blood flow, and neural structure measurements in glaucoma.

    Science.gov (United States)

    Hwang, John C; Konduru, Ranjith; Zhang, Xinbo; Tan, Ou; Francis, Brian A; Varma, Rohit; Sehi, Mitra; Greenfield, David S; Sadda, Srinivas R; Huang, David

    2012-05-17

    To determine the relationship among visual field, neural structural, and blood flow measurements in glaucoma. Case-control study. Forty-seven eyes of 42 patients with perimetric glaucoma were age-matched with 27 normal eyes of 27 patients. All patients underwent Doppler Fourier-domain optical coherence tomography to measure retinal blood flow and standard glaucoma evaluation with visual field testing and quantitative structural imaging. Linear regression analysis was performed to analyze the relationship among visual field, blood flow, and structure, after all variables were converted to logarithmic decibel scale. Retinal blood flow was reduced in glaucoma eyes compared to normal eyes (P flow and structural loss of rim area and retinal nerve fiber layer (RNFL). There was no correlation or paradoxical correlation between blood flow and structure. Multivariate regression analysis revealed that reduced blood flow and structural loss are independent predictors of visual field loss. Each dB decrease in blood flow was associated with at least 1.62 dB loss in mean deviation (P ≤ 0.001), whereas each dB decrease in rim area and RNFL was associated with 1.15 dB and 2.56 dB loss in mean deviation, respectively (P ≤ 0.03). There is a close link between reduced retinal blood flow and visual field loss in glaucoma that is largely independent of structural loss. Further studies are needed to elucidate the causes of the vascular dysfunction and potential avenues for therapeutic intervention. Blood flow measurement may be useful as an independent assessment of glaucoma severity.

  20. Applying Exploratory Structural Equation Modeling to Examine the Student-Teacher Relationship Scale in a Representative Greek Sample.

    Science.gov (United States)

    Tsigilis, Nikolaos; Gregoriadis, Athanasios; Grammatikopoulos, Vasilis; Zachopoulou, Evridiki

    2018-01-01

    Teacher-child relationships in early childhood are a fundamental prerequisite for children's social, emotional, and academic development. The Student-Teacher Relationship Scale (STRS) is one of the most widely accepted and used instruments that evaluate the quality of teacher-child relationships. STRS is a 28-item questionnaire that assess three relational dimensions, Closeness, Conflict, and Dependency. The relevant literature has shown a pattern regarding the difficulty to support the STRS factor structure with CFA, while it is well-documented with EFA. Recently, a new statistical technique was proposed to combine the best of the CFA and EFA namely, the Exploratory Structural Equation Modeling (ESEM). The purpose of this study was (a) to examine the factor structure of the STRS in a Greek national sample. Toward this end, the ESEM framework was applied in order to overcome the limitations of EFA and CFA, (b) to confirm previous findings about the cultural influence in teacher-child relationship patterns, and (c) to examine the invariance of STRS across gender and age. Early educators from a representative Greek sample size of 535 child care and kindergarten centers completed the STRS for 4,158 children. CFA as well as ESEM procedures were implemented. Results showed that ESEM provided better fit to the data than CFA in both groups, supporting the argument that CFA is an overly restrictive approach in comparison to ESEM for the study of STRS. All primary loadings were statistically significant and were associated with their respective latent factors. Contrary to the existing literature conducted in USA and northern Europe, the association between Closeness and Dependency yielded a positive correlation. This finding is in line with previous studies conducted in Greece and confirm the existence of cultural differences in teacher-child relationships. In addition, findings supported the configural, metric, scalar, and variance/covariance equivalence of the STRS

  1. Applying Exploratory Structural Equation Modeling to Examine the Student-Teacher Relationship Scale in a Representative Greek Sample

    Directory of Open Access Journals (Sweden)

    Nikolaos Tsigilis

    2018-05-01

    Full Text Available Teacher-child relationships in early childhood are a fundamental prerequisite for children's social, emotional, and academic development. The Student-Teacher Relationship Scale (STRS is one of the most widely accepted and used instruments that evaluate the quality of teacher-child relationships. STRS is a 28-item questionnaire that assess three relational dimensions, Closeness, Conflict, and Dependency. The relevant literature has shown a pattern regarding the difficulty to support the STRS factor structure with CFA, while it is well-documented with EFA. Recently, a new statistical technique was proposed to combine the best of the CFA and EFA namely, the Exploratory Structural Equation Modeling (ESEM. The purpose of this study was (a to examine the factor structure of the STRS in a Greek national sample. Toward this end, the ESEM framework was applied in order to overcome the limitations of EFA and CFA, (b to confirm previous findings about the cultural influence in teacher-child relationship patterns, and (c to examine the invariance of STRS across gender and age. Early educators from a representative Greek sample size of 535 child care and kindergarten centers completed the STRS for 4,158 children. CFA as well as ESEM procedures were implemented. Results showed that ESEM provided better fit to the data than CFA in both groups, supporting the argument that CFA is an overly restrictive approach in comparison to ESEM for the study of STRS. All primary loadings were statistically significant and were associated with their respective latent factors. Contrary to the existing literature conducted in USA and northern Europe, the association between Closeness and Dependency yielded a positive correlation. This finding is in line with previous studies conducted in Greece and confirm the existence of cultural differences in teacher-child relationships. In addition, findings supported the configural, metric, scalar, and variance/covariance equivalence of

  2. Relationships between the structure of wheat gluten and ACE inhibitory activity of hydrolysate: stepwise multiple linear regression analysis.

    Science.gov (United States)

    Zhang, Yanyan; Ma, Haile; Wang, Bei; Qu, Wenjuan; Wali, Asif; Zhou, Cunshan

    2016-08-01

    Ultrasound pretreatment of wheat gluten (WG) before enzymolysis can improve the angiotensin converting enzyme (ACE) inhibitory activity of the hydrolysates by alerting the structure of substrate proteins. Establishment of a relationship between the structure of WG and ACE inhibitory activity of the hydrolysates to judge the end point of the ultrasonic pretreatment is vital. The results of stepwise multiple linear regression (MLR) showed that the contents of free sulfhydryl, α-helix, disulfide bond, surface hydrophobicity and random coil were significantly correlated to ACE Inhibitory activity of the hydrolysate, with the standard partial regression coefficients were 3.729, -0.676, -0.252, 0.022 and 0.156, respectively. The R(2) of this model was 0.970. External validation showed that the stepwise MLR model could well predict the ACE inhibitory activity of hydrolysate based on the content of free sulfhydryl, α-helix, disulfide bond, surface hydrophobicity and random coil of WG before hydrolysis. A stepwise multiple linear regression model describing the quantitative relationships between the structure of WG and the ACE Inhibitory activity of the hydrolysates was established. This model can be used to predict the endpoint of the ultrasonic pretreatment. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  3. Structure-affinity relationship in the interactions of human organic anion transporter 1 with caffeine, theophylline, theobromine and their metabolites.

    Science.gov (United States)

    Sugawara, Mitsuru; Mochizuki, Takahiro; Takekuma, Yoh; Miyazaki, Katsumi

    2005-08-15

    It is well known that human organic anion transporter 1 (hOAT1) transports many kinds of drugs, endogenous compounds, and toxins. However, little is known about the structure-affinity relationship. The aim of this study was to elucidate the structure-affinity relationship using a series of structurally related compounds that interact with hOAT1. Inhibitory effects of xanthine- and uric acid-related compounds on the transport of p-aminohippuric acid were examined using CHO-K1 cells stably expressing hOAT1. The order of potency for the inhibitory effects of xanthine-related compounds on PAH uptake was 1-methyl derivative>7-methyl derivative>3-methyl derivative falling dotsxanthine>1,3,7-trimethyl derivative (caffeine). The order of potency of the inhibition was 1,3,7-trimethyluric acid>1,3-dimethyluric acid>1,7-dimethyluric acid>1-methyluric acid>uric acid. A significant correlation between inhibitory potency and lipophilicity of the tested uric acid-related compounds was observed. The main determinant of the affinity of xanthine-related compounds is the position of the methyl group. On the other hand, lipophilicity is the main determinant of the affinity of uric acid-related compounds.

  4. Dysphagia disorders in patients with cancer of the oropharynx are significantly affected by the radiation therapy dose to the superior and middle constrictor muscle: A dose-effect relationship

    International Nuclear Information System (INIS)

    Levendag, Peter C.; Teguh, David N.; Voet, Peter; Est, Henri van der; Noever, Inge; Kruijf, Wilhelmus J.M. de; Kolkman-Deurloo, Inger-Karine; Prevost, Jean-Briac; Poll, Johan; Schmitz, Paul I.M.; Heijmen, Ben J.

    2007-01-01

    Purpose/Objective: To assess the relationship between the radiation therapy (RT) dose received by the muscular components of the swallowing (sw) apparatus and - dysphagia related - quality of life (QoL) in oropharyngeal cancer. Materials/Methods: Between 2000 and 2005, 81 patients with SCC of the oropharynx were treated by 3DCRT or IMRT, with or without concomitant chemotherapy (CHT); 43 out of these 81 patients were boosted by brachytherapy (BT). Charts of 81 patients were reviewed with regard to late dysphagia complaints; 23% experienced severe dysphagia. Seventeen patients expired. Fifty-six out of 64 (88%) responded to quality of life (QoL) questionnaires; that is, the Performance Status Scales of List, EORTC H and N35, and the M.D. Anderson Dysphagia Inventory. The superior (scm), middle (mcm), and inferior constrictor muscle (icm), the cricopharyngeus muscle and the inlet of the esophagus, are considered of paramount importance for swallowing. The mean dose was calculated in the muscular structures. Univariate analysis and multivariate analysis were performed using the proportional odds model. Results: Mean follow-up was 18 months (range 2-34) for IMRT, and 46 months for 3DCRT (range 2-72). At 3-years, a LRC of 84%, DFS of 78% and OS of 77% were observed. A significant correlation was observed between the mean dose in the scm and mcm, and severe dysphagia complaints (univariate analysis). A steep dose-effect relationship, with an increase of the probability of dysphagia of 19% with every additional 10 Gy, was established. In the multivariate analysis, BT (dose) was the only significant factor. Conclusion: A dose-effect relationship between dose and swallowing complaints was observed. One way to improve the QoL is to constrain the dose to be received by the swallowing muscles

  5. Methanol oxidation reaction on core-shell structured Ruthenium-Palladium nanoparticles: Relationship between structure and electrochemical behavior

    Science.gov (United States)

    Kübler, Markus; Jurzinsky, Tilman; Ziegenbalg, Dirk; Cremers, Carsten

    2018-01-01

    In this work the relationship between structural composition and electrochemical characteristics of Palladium(Pd)-Ruthenium(Ru) nanoparticles during alkaline methanol oxidation reaction is investigated. The comparative study of a standard alloyed and a precisely Ru-core-Pd-shell structured catalyst allows for a distinct investigation of the electronic effect and the bifunctional mechanism. Core-shell catalysts benefit from a strong electronic effect and an efficient Pd utilization. It is found that core-shell nanoparticles are highly active towards methanol oxidation reaction for potentials ≥0.6 V, whereas alloyed catalysts show higher current outputs in the lower potential range. However, differential electrochemical mass spectrometry (DEMS) experiments reveal that the methanol oxidation reaction on core-shell structured catalysts proceeds via the incomplete oxidation pathway yielding formaldehyde, formic acid or methyl formate. Contrary, the alloyed catalyst benefits from the Ru atoms at its surface. Those are found to be responsible for high methanol oxidation activity at lower potentials as well as for complete oxidation of CH3OH to CO2 via the bifunctional mechanism. Based on these findings a new Ru-core-Pd-shell-Ru-terrace catalyst was synthesized, which combines the advantages of the core-shell structure and the alloy. This novel catalyst shows high methanol electrooxidation activity as well as excellent selectivity for the complete oxidation pathway.

  6. Micro-, to nano-structural relationships in natural serpentines, derived from cationic substitutions.

    Science.gov (United States)

    Munoz, M.; Farges, F.; Andreani, M.; Ulrich, M.; Marcaillou, C.; Mathon, O.

    2014-12-01

    The understanding of the crystal chemistry of serpentine minerals (incl. antigorite, lizardite and chrysotile) is fundamental since serpentinization processes concern very large scientific domains: e.g., natural abiotic hydrogen production (Marcaillou et al., 2011), origins of life (Russell et al., 2010), fluid properties and mobility of metals in subduction zones (Kelley and Cottrell, 2009). This study aims at characterizing relations between the micro-, and nano-structures of the most abundant serpentine polytypes in the oceanic crust. Serpentine theoretical formula is Mg3Si2O5(OH)4 but several natural substitutions are possible and the formula may be written such as: (Mg,Fe2+,Fe3+,Al)3(Si,Al,Fe3+)2O5(OH)4; showing that Fe and Al may play an important role in the crystallization of serpentines. Preliminary crystal chemistry studies, suggest that, 1) the Al content alone cannot be directly correlated to serpentine polytypes (Andreani et al., 2008), 2) the amounts of tetrahedral iron can be significant in the presence of ferric iron (Marcaillou et al., 2011). Because magnetite is usually associated to serpentine, the Fe-speciation characterization of serpentine is delicate. Here, we provide the study of 33 magnetite-free serpentines containing various amounts of Fe and Al. The samples were characterized by SEM, Raman, XRF, as well as XANES, pre-edge, and EXAFS spectroscopy at the Fe K-edge. XANES experimental data were crosschecked and interpreted thanks to ab initio calculations and EXAFS shell-fitting. Also, preliminary 27Al-RMN data is presented. Results suggest relationships between the type and amount of substitution of trivalent cations in minerals, and the microstructures observed. Chrysotile incorporates less trivalent cations than other varieties, which tends to preserve the so-called misfit between the TO layers, and therefore the tubular structure of the mineral. Lizardites mainly involve Fe/Al Tschermak-type substitutions, while M-site vacancy charge

  7. Structure-function relationship of tear film lipid layer: A contemporary perspective.

    Science.gov (United States)

    Georgiev, Georgi As; Eftimov, Petar; Yokoi, Norihiko

    2017-10-01

    Tear film lipid layer (TFLL) stabilizes the air/tear surface of the human eye. Meibomian gland dysfunction (MGD) resulting in quantitative and qualitative modifications of TFLL major (>93%) component, the oily secretion of meibomian lipids (MGS), is the world leading cause of dry eye syndrome (DES) with up to 86% of all DES patients showing signs of MGD. Caused by intrinsic factors (aging, ocular and general diseases) and by extrinsic everyday influences like contact lens wear and extended periods in front of a computer screen, DES (resulting in TF instability, visual disturbances and chronic ocular discomfort) is the major ophthalmic public health disease of the present time affecting the quality of life of 10-30% of the human population worldwide. Therefore there is a pressing need to summarize the present knowledge, contradictions and open questions to be resolved in the field of TFLL composition/structure/functions relationship. The following major aspects are covered by the review: (i) Do we have a reliable mimic for TFLL: MGS vs contact lens lipid extracts (CLLE) vs lipid extracts from whole tears. Does TFLL truly consist of lipids only or it is important to keep in mind the TF proteins as well?; (ii) Structural properties of TFLL and of its mimics in health and disease in vitro and in vivo. How the TFLL uniformity and thickness ensures the functionality of the lipid layer (barrier to evaporation, surface properties, TF stability etc.); (iii) What are the main functions of the TFLL? In this aspect an effort is done to emphasize that there is no single main function of TFLL but instead it simultaneously fulfills plethora of functions: suppresses the evaporation (alone or probably in cooperation with other TF constituents) of the aqueous tears; stabilizes (due to its surface properties) the air/tear surface at eye opening and during the interblink interval; and even acts as a first line of defense against bacterial invasion due to its detergency action on the

  8. Anti-proliferation activity of terpenoids isolated from Euphorbia kansui in human cancer cells and their structure-activity relationship.

    Science.gov (United States)

    Hou, Jin-Jun; Shen, Yao; Yang, Zhou; Fang, Lin; Cai, Lu-Ying; Yao, Shuai; Long, Hua-Li; Wu, Wan-Ying; Guo, De-An

    2017-10-01

    Euphorbia kansui is a commonly used traditional Chinese medicine for the treatment of edema, pleural effusion, and asthma, etc. According to the previous researches, terpenoids in E. kansui possess various biological activities, e.g., anti-virus, anti-allergy, antitumor effects. In this work, twenty five terpenoids were isolated from E. kansui, including thirteen ingenane- and eight jatrophane-type diterpenoids (with two new compounds, kansuinin P and Q) and four triterpenoids. Eighteen of them were analyzed by MTS assay for in vitro anticancer activity in five human cancer cell lines. Structure-activity relationship for 12 ingenane-type diterpenoids in colorectal cancer Colo205 cells were preliminary studied. Significant anti-proliferation activities were observed in human melanoma cells breast cancer MDA-MB-435 cells and Colo205 cells. More than half of the isolated ingenane-type diterpenoids showed inhibitory activities in MDA-MB-435 cells. Eight ingenane- and one jatrophane-type diterpenoids possessed much lower IC 50 values in MDA-MB-435 cells than positive control staurosporine. Preliminary structure-activity relationship analysis showed that substituent on position 20 was important for the activity of ingenane-type diterpenoids in Colo205 cells and substituent on position 3 contributed more significant biological activity of the compounds than that on position 5 in both MDA-MB-435 and Colo205 cells. Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  9. Structure-property relationship in cytotoxicity and cell uptake of poly(2-oxazoline) amphiphiles

    KAUST Repository

    Luxenhofer, Robert

    2011-07-01

    The family of poly(2-oxazoline)s (POx) is being increasingly investigated in the context of biomedical applications. We tested the relative cytotoxicity of POx and were able to confirm that these polymers are typically not cytotoxic even at high concentrations. Furthermore, we report structure-uptake relationships of a series of amphiphilic POx block copolymers that have different architectures, molar mass and chain termini. The rate of endocytosis can be fine-tuned over a broad range by changing the polymer structure. The cellular uptake increases with the hydrophobic character of the polymers and is observed even at nanomolar concentrations. Considering the structural versatility of this class of polymers, the relative ease of preparation and their stability underlines the potential of POx as a promising platform candidate for the preparation of next-generation polymer therapeutics.

  10. Structure-activity relationships of heterogeneous catalysts from time-resolved X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Ressler, T.; Jentoft, R.E.; Wienold, J.; Girgsdies, F.; Neisius, T.; Timpe, O.

    2003-01-01

    Knowing the composition and the evolution of the bulk structure of a heterogeneous catalyst under working conditions (in situ) is a pre-requisite for understanding structure-activity relationships. X-ray absorption spectroscopy can be employed to study a catalytically active material in situ. In addition to steady-state investigations, the technique permits experiments with a time-resolution in the sub-second range to elucidate the solid-state kinetics of the reactions involved. Combined with mass spectrometry, the evolution of the short-range order structure of a heterogeneous catalyst, the average valence of the constituent metals, and the phase composition can be obtained. Here we present results obtained from time-resolved studies on the reduction of MoO 3 in propene and in propene and oxygen

  11. Relationship between Chemical Structure and Antimicrobial Activities of Isothiocyanates from Cruciferous Vegetables against Oral Pathogens.

    Science.gov (United States)

    Ko, Mi-Ok; Kim, Mi-Bo; Lim, Sang-Bin

    2016-12-28

    We evaluated the potentials of 10 isothiocyanates (ITCs) from cruciferous vegetables and radish root hydrolysate for inhibiting the growth of oral pathogens, with an emphasis on assessing any structure-function relationship. Structural differences in ITCs impacted their antimicrobial activities against oral pathogens differently. The indolyl ITC (indol-3-carbinol) was the most potent inhibitor of the growth of oral pathogens, followed by aromatic ITCs (benzyl ITC (BITC) and phenylethyl ITC (PEITC)) and aliphatic ITCs (erucin, iberin, and sulforaphene). Sulforaphene, which is similar in structure, but has one double bond, showed higher antimicrobial activity than sulforaphane. Erucin, which has a thiol group, showed higher antimicrobial activity than sulforaphane, which has a sulfinyl group. BITC and iberin with a short chain exhibited higher antimicrobial potential than PEITC and sulforaphane with a longer chain, respectively. ITCs have strong antimicrobial activities and may be useful in the prevention and management of dental caries.

  12. Molecular Descriptors Family on Structure Activity Relationships 6. Octanol-Water Partition Coefficient of Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2006-01-01

    Full Text Available Octanol-water partition coefficient of two hundred and six polychlorinated biphenyls was model by the use of an original method based on complex information obtained from compounds structure. The regression analysis shows that best results are obtained in four-varied model (r2 = 0.9168. The prediction ability of the model was studied through leave-one-out analysis (r2cv(loo = 0.9093 and in training and test sets analysis. Modeling the octanol-water partition coefficient of polychlorinated biphenyls by integration of complex structural information provide a stable and performing four-varied model, allowing us to make remarks about relationship between structure of polychlorinated biphenyls and associated octanol-water partition coefficients.

  13. Structure-Property Relationships and the Mixed Network Former Effect in Boroaluminosilicate Glasses

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Potuzak, Marcel; Mauro, John C.

    compositions by substituting Al2O3 for SiO2. We also investigate the various roles of sodium in the glasses including charge compensation of tetrahedral aluminum and boron atoms and formation of non-bridging oxygen. We find that mechanical properties (density, elastic moduli, and hardness), glass transition......Boroaluminosilicate glasses are important materials for various applications, e.g., liquid crystal display substrates, glass fibers for reinforcement, and thermal shock-resistant glass containers. The complicated structural speciation in these glasses leads to a mixed network former effect yielding...... nonlinear variation in many macroscopic properties. It is therefore crucial to investigate and understand structure-property correlations in boroaluminosilicate glasses. Here we study the structure-property relationships of a range of sodium boroaluminosilicate glasses from peralkaline to peraluminous...

  14. Boiling points of halogenated aliphatic compounds: a quantitative structure-property relationship for prediction and validation.

    Science.gov (United States)

    Oberg, Tomas

    2004-01-01

    Halogenated aliphatic compounds have many technical uses, but substances within this group are also ubiquitous environmental pollutants that can affect the ozone layer and contribute to global warming. The establishment of quantitative structure-property relationships is of interest not only to fill in gaps in the available database but also to validate experimental data already acquired. The three-dimensional structures of 240 compounds were modeled with molecular mechanics prior to the generation of empirical descriptors. Two bilinear projection methods, principal component analysis (PCA) and partial-least-squares regression (PLSR), were used to identify outliers. PLSR was subsequently used to build a multivariate calibration model by extracting the latent variables that describe most of the covariation between the molecular structure and the boiling point. Boiling points were also estimated with an extension of the group contribution method of Stein and Brown.

  15. Cationic lipids: molecular structure/ transfection activity relationships and interactions with biomembranes.

    Science.gov (United States)

    Koynova, Rumiana; Tenchov, Boris

    2010-01-01

    Abstract Synthetic cationic lipids, which form complexes (lipoplexes) with polyanionic DNA, are presently the most widely used constituents of nonviral gene carriers. A large number of cationic amphiphiles have been synthesized and tested in transfection studies. However, due to the complexity of the transfection pathway, no general schemes have emerged for correlating the cationic lipid chemistry with their transfection efficacy and the approaches for optimizing their molecular structures are still largely empirical. Here we summarize data on the relationships between transfection activity and cationic lipid molecular structure and demonstrate that the transfection activity depends in a systematic way on the lipid hydrocarbon chain structure. A number of examples, including a large series of cationic phosphatidylcholine derivatives, show that optimum transfection is displayed by lipids with chain length of approximately 14 carbon atoms and that the transfection efficiency strongly increases with increase of chain unsaturation, specifically upon replacement of saturated with monounsaturated chains.

  16. The two-layer geochemical structure of modern biogeochemical provinces and its significance for spatially adequate ecological evaluations and decisions

    Science.gov (United States)

    Korobova, Elena; Romanov, Sergey

    2014-05-01

    Contamination of the environment has reached such a scale that ecogeochemical situation in any area can be interpreted now as a result of the combined effect of natural and anthropogenic factors. The areas that appear uncomfortable for a long stay can have natural and anthropogenic genesis, but the spatial structure of such biogeochemical provinces is in any case formed of a combination of natural and technogenic fields of chemical elements. Features of structural organization and the difference in factors and specific time of their formation allow their separation on one hand and help in identification of areas with different ecological risks due to overlay of the two structures on the other. Geochemistry of soil cover reflects the long-term result of the naturally balanced biogeochemical cycles, therefore the soil geochemical maps of the undisturbed areas may serve the basis for evaluation of the natural geochemical background with due regard to the main factors of geochemical differentiation in biosphere. Purposeful and incidental technogenic concentrations and dispersions of chemical elements of specific (mainly mono- or polycentric) structure are also fixed in soils that serve as secondary sources of contamination of the vegetation cover and local food chains. Overlay of the two structures forms specific heterogeneity of modern biogeochemical provinces with different risk for particular groups of people, animals and plants adapted to specific natural geochemical background within particular concentration interval. The developed approach is believed to be helpful for biogeochemical regionalizing of modern biosphere (noosphere) and for spatially adequate ecogeochemical evaluation of the environment and landuse decisions. It allows production of a set of applied geochemical maps such as: 1) health risk due to chemical elements deficiency and technogenic contamination accounting of possible additive effects; 2) adequate soil fertilization and melioration with due

  17. Structured social relationships: a review of volunteer home visiting programs for parents of young children.

    Science.gov (United States)

    Byrne, Fiona; Grace, Rebekah; Tredoux, Jaimie; Kemp, Lynn

    2016-06-01

    Objective The aims of the present paper were to: (1) review the research literature that contributes to an understanding of the role of volunteer home visiting programs in supporting the health and well being of families with young children; and (2) propose a conceptual model outlining service pathways for families in need of additional support. Methods An integrative literature review method was used, with a mix of electronic and manual search methods for the period January 1980-January 2014. Forty-five studies were identified that met the inclusion criteria for review and were coded according to themes developed a priori. Results There is little formal research that has examined the effectiveness of volunteer home visiting programs for supporting family health and well being. The available research suggests that volunteer home visiting programs provide socioemotional support through structured social relationships; however, there is limited empirical evidence to explicate the factors that contribute to these outcomes. Conclusion In recognition of the importance of peer support for new parents, the not-for-profit sector has been involved in providing volunteer home visiting services to families for decades. However, the body of research to support this work is characterised by methodological limitations, and rigorous evidence is limited. What is clear anecdotally and qualitatively from the existing research is that parents who are in need of additional support value engagement with a community volunteer. These structured social relationships appear to fulfil a service need within the community, helping build bridges to support social networks, and thus complementing professional services and relationships. Overall, structured social relationships in the form of volunteer home visiting programs appear to provide an important pathway to support family health and well being. Findings from the existing research are mixed and often characterised by methodological

  18. Relationships Between Lower-Body Muscle Structure and Lower-Body Strength, Power, and Muscle-Tendon Complex Stiffness.

    Science.gov (United States)

    Secomb, Josh L; Lundgren, Lina E; Farley, Oliver R L; Tran, Tai T; Nimphius, Sophia; Sheppard, Jeremy M

    2015-08-01

    The purpose of this study was to determine whether any relationships were present between lower-body muscle structure and strength and power qualities. Fifteen elite male surfing athletes performed a battery of lower-body strength and power tests, including countermovement jump (CMJ), squat jump (SJ), isometric midthigh pull (IMTP), and had their lower-body muscle structure assessed with ultrasonography. In addition, lower-body muscle-tendon complex (MTC) stiffness and dynamic strength deficit (DSD) ratio were calculated from the CMJ and IMTP. Significant relationships of large to very large strength were observed between the vastus lateralis (VL) thickness of the left (LVL) and right (RVL) leg and peak force (PF) (r = 0.54-0.77, p well as IMTP PF (r = 0.53-0.60, p = 0.02-0.04). Furthermore, large relationships were found between left lateral gastrocnemius (LG) pennation angle and SJ and IMTP PF (r = 0.53, p = 0.04, and r = 0.70, p < 0.01, respectively) and between LG and IMTP relative PF (r = 0.63, p = 0.01). Additionally, large relationships were identified between lower-body MTC stiffness and DSD ratio (r = 0.68, p < 0.01), right (LG) pennation angle (r = 0.51, p = 0.05), CMJ PF (r = 0.60, p = 0.02), and jump height (r = 0.53, p = 0.04). These results indicate that greater VL thickness and increased LG pennation angle are related to improved performance in the CMJ, SJ, and IMTP. Furthermore, these results suggest that lower-body MTC stiffness explains a large amount of variance in determining an athlete's ability to rapidly apply force during a dynamic movement.

  19. Free and Open Source Chemistry Software in Research of Quantitative Structure-Toxicity Relationship of Pesticides

    Directory of Open Access Journals (Sweden)

    Rastija Vesna

    2017-01-01

    Full Text Available Pesticides are toxic chemicals aimed for the destroying pest on crops. Numerous data evidence about toxicity of pesticides on aquatic organisms. Since pesticides with similar properties tend to have similar biological activities, toxicity may be predicted from structure. Their structure feature and properties are encoded my means of molecular descriptors. Molecular descriptors can capture quite simple two-dimensional (2D chemical structures to highly complex three-dimensional (3D chemical structures. Quantitative structure-toxicity relationship (QSTR method uses linear regression analyses for correlation toxicity of chemical with their structural feature using molecular descriptors. Molecular descriptors were calculated using open source software PaDEL and in-house built PyMOL plugin (PyDescriptor. PyDescriptor is a new script implemented with the commonly used visualization software PyMOL for calculation of a large and diverse set of easily interpretable molecular descriptors encoding pharmacophoric patterns and atomic fragments. PyDescriptor has several advantages like free and open source, can work on all major platforms (Windows, Linux, MacOS. QSTR method allows prediction of toxicity of pesticides without experimental assay. In the present work, QSTR analysis for toxicity of a dataset of mixtures of 5 classes of pesticides comprising has been performed.

  20. Atomic Scale Structure-Chemistry Relationships at Oxide Catalyst Surfaces and Interfaces

    Science.gov (United States)

    McBriarty, Martin E.

    Oxide catalysts are integral to chemical production, fuel refining, and the removal of environmental pollutants. However, the atomic-scale phenomena which lead to the useful reactive properties of catalyst materials are not sufficiently understood. In this work, the tools of surface and interface science and electronic structure theory are applied to investigate the structure and chemical properties of catalytically active particles and ultrathin films supported on oxide single crystals. These studies focus on structure-property relationships in vanadium oxide, tungsten oxide, and mixed V-W oxides on the surfaces of alpha-Al2O3 and alpha-Fe2O 3 (0001)-oriented single crystal substrates, two materials with nearly identical crystal structures but drastically different chemical properties. In situ synchrotron X-ray standing wave (XSW) measurements are sensitive to changes in the atomic-scale geometry of single crystal model catalyst surfaces through chemical reaction cycles, while X-ray photoelectron spectroscopy (XPS) reveals corresponding chemical changes. Experimental results agree with theoretical calculations of surface structures, allowing for detailed electronic structure investigations and predictions of surface chemical phenomena. The surface configurations and oxidation states of V and W are found to depend on the coverage of each, and reversible structural shifts accompany chemical state changes through reduction-oxidation cycles. Substrate-dependent effects suggest how the choice of oxide support material may affect catalytic behavior. Additionally, the structure and chemistry of W deposited on alpha-Fe 2O3 nanopowders is studied using X-ray absorption fine structure (XAFS) measurements in an attempt to bridge single crystal surface studies with real catalysts. These investigations of catalytically active material surfaces can inform the rational design of new catalysts for more efficient and sustainable chemistry.

  1. The complete chloroplast genome sequence of Mahonia bealei (Berberidaceae) reveals a significant expansion of the inverted repeat and phylogenetic relationship with other angiosperms.

    Science.gov (United States)

    Ma, Ji; Yang, Bingxian; Zhu, Wei; Sun, Lianli; Tian, Jingkui; Wang, Xumin

    2013-10-10

    Mahonia bealei (Berberidaceae) is a frequently-used traditional Chinese medicinal plant with efficient anti-inflammatory ability. This plant is one of the sources of berberine, a new cholesterol-lowering drug with anti-diabetic activity. We have sequenced the complete nucleotide sequence of the chloroplast (cp) genome of M. bealei. The complete cp genome of M. bealei is 164,792 bp in length, and has a typical structure with large (LSC 73,052 bp) and small (SSC 18,591 bp) single-copy regions separated by a pair of inverted repeats (IRs 36,501 bp) of large size. The Mahonia cp genome contains 111 unique genes and 39 genes are duplicated in the IR regions. The gene order and content of M. bealei are almost unarranged which is consistent with the hypothesis that large IRs stabilize cp genome and reduce gene loss-and-gain probabilities during evolutionary process. A large IR expansion of over 12 kb has occurred in M. bealei, 15 genes (rps19, rpl22, rps3, rpl16, rpl14, rps8, infA, rpl36, rps11, petD, petB, psbH, psbN, psbT and psbB) have expanded to have an additional copy in the IRs. The IR expansion rearrangement occurred via a double-strand DNA break and subsequence repair, which is different from the ordinary gene conversion mechanism. Repeat analysis identified 39 direct/inverted repeats 30 bp or longer with a sequence identity ≥ 90%. Analysis also revealed 75 simple sequence repeat (SSR) loci and almost all are composed of A or T, contributing to a distinct bias in base composition. Comparison of protein-coding sequences with ESTs reveals 9 putative RNA edits and 5 of them resulted in non-synonymous modifications in rpoC1, rps2, rps19 and ycf1. Phylogenetic analysis using maximum parsimony (MP) and maximum likelihood (ML) was performed on a dataset composed of 65 protein-coding genes from 25 taxa, which yields an identical tree topology as previous plastid-based trees, and provides strong support for the sister relationship between Ranunculaceae and Berberidaceae

  2. The Relationship Between Low-Frequency Motions and Community Structure of Residue Network in Protein Molecules.

    Science.gov (United States)

    Sun, Weitao

    2018-01-01

    The global shape of a protein molecule is believed to be dominant in determining low-frequency deformational motions. However, how structure dynamics relies on residue interactions remains largely unknown. The global residue community structure and the local residue interactions are two important coexisting factors imposing significant effects on low-frequency normal modes. In this work, an algorithm for community structure partition is proposed by integrating Miyazawa-Jernigan empirical potential energy as edge weight. A sensitivity parameter is defined to measure the effect of local residue interaction on low-frequency movement. We show that community structure is a more fundamental feature of residue contact networks. Moreover, we surprisingly find that low-frequency normal mode eigenvectors are sensitive to some local critical residue interaction pairs (CRIPs). A fair amount of CRIPs act as bridges and hold distributed structure components into a unified tertiary structure by bonding nearby communities. Community structure analysis and CRIP detection of 116 catalytic proteins reveal that breaking up of a CRIP can cause low-frequency allosteric movement of a residue at the far side of protein structure. The results imply that community structure and CRIP may be the structural basis for low-frequency motions.

  3. Functional significance of the oligomeric structure of the Na,K-pump from radiation inactivation and ligand binding

    International Nuclear Information System (INIS)

    Norby, J.G.; Jensen, J.

    1991-01-01

    The present article is concerned with the oligomeric structure and function of the Na,K-pump (Na,K-ATPase). The questions we have addressed, using radiation inactivation and target size analysis as well as ligand binding, are whether the minimal structural unit and the functional unit have more than one molecule of the catalytic subunit, alpha. The authors first discuss the fundamentals of the radiation inactivation method and emphasize the necessity for rigorous internal standardization with enzymes of known molecular mass. They then demonstrate that the radiation inactivation of Na,K-ATPase is a stepwise process which leads to intermediary fragments of the alpha-subunit with partial catalytic activity. From the target size analysis it is most likely that the membrane-bound Na,K-ATPase is structurally organized as a diprotomer containing two alpha-subunits. Determination of ADP- and ouabain-binding site stoichiometry favors a theory with one substrate site per (alpha beta) 2. 47 references

  4. Structure and further fragmentation of significant [a3 + Na - H]+ ions from sodium-cationized peptides.

    Science.gov (United States)

    Wang, Huixin; Wang, Bing; Wei, Zhonglin; Zhang, Hao; Guo, Xinhua

    2015-01-01

    A good understanding of gas-phase fragmentation chemistry of peptides is important for accurate protein identification. Additional product ions obtained by sodiated peptides can provide useful sequence information supplementary to protonated peptides and improve protein identification. In this work, we first demonstrate that the sodiated a3 ions are abundant in the tandem mass spectra of sodium-cationized peptides although observations of a3 ions have rarely been reported in protonated peptides. Quantum chemical calculations combined with tandem mass spectrometry are used to investigate this phenomenon by using a model tetrapeptide GGAG. Our results reveal that the most stable [a3 + Na - H](+) ion is present as a bidentate linear structure in which the sodium cation coordinates to the two backbone carbonyl oxygen atoms. Due to structural inflexibility, further fragmentation of the [a3 + Na - H](+) ion needs to overcome several relatively high energetic barriers to form [b2 + Na - H](+) ion with a diketopiperazine structure. As a result, low abundance of [b2 + Na - H](+) ion is detected at relatively high collision energy. In addition, our computational data also indicate that the common oxazolone pathway to generate [b2 + Na - H](+) from the [a3 + Na - H](+) ion is unlikely. The present work provides a mechanistic insight into how a sodium ion affects the fragmentation behaviors of peptides. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Analysis of structural relationship among the occupational dysfunction on the psychological problem in healthcare workers: a study using structural equation modeling.

    Science.gov (United States)

    Teraoka, Mutsumi; Kyougoku, Makoto

    2015-01-01

    Purpose. The purpose of this study is to demonstrate the hypothetical model based on structural relationship with the occupational dysfunction on psychological problems (stress response, burnout syndrome, and depression) in healthcare workers. Method. Three cross sectional studies were conducted to assess the following relations: (1) occupational dysfunction on stress response (n = 468), (2) occupational dysfunction on burnout syndrome (n = 1,142), and (3) occupational dysfunction on depression (n = 687). Personal characteristics were collected through a questionnaire (such as age, gender, and job category, opportunities for refreshment, time spent on leisure activities, and work relationships) as well as the Classification and Assessment of Occupational Dysfunction (CAOD). Furthermore, study 1 included the Stress Response Scale-18 (SRS-18), study 2 used the Japanese Burnout Scale (JBS), and study 3 employed the Center for Epidemiological Studies Depression Scale (CES-D). The Kolmogorov-Smirnov test, confirmatory factor analysis (CFA), exploratory factor analysis (EFA), and path analysis of structural equation modeling (SEM) analysis were used in all of the studies. EFA and CFA were used to measure structural validity of four assessments; CAOD, SRS-18, JBS, and CES-D. For examination of a potential covariate, we assessed the correlation of the total and factor score of CAOD and personal factors in all studies. Moreover, direct and indirect effects of occupational dysfunction on stress response (Study 1), burnout syndrome (Study 2), and depression (Study 3) were also analyzed. Results. In study 1, CAOD had 16 items and 4 factors. In Study 2 and 3, CAOD had 16 items and 5 factors. SRS-18 had 18 items and 3 factors, JBS had 17 items and 3 factors, and CES-D had 20 items and 4 factors. All studies found that there were significant correlations between the CAOD total score and the personal factor that included opportunities for refreshment, time spent on leisure

  6. Analysis of structural relationship among the occupational dysfunction on the psychological problem in healthcare workers: a study using structural equation modeling

    Directory of Open Access Journals (Sweden)

    Mutsumi Teraoka

    2015-11-01

    Full Text Available Purpose. The purpose of this study is to demonstrate the hypothetical model based on structural relationship with the occupational dysfunction on psychological problems (stress response, burnout syndrome, and depression in healthcare workers.Method. Three cross sectional studies were conducted to assess the following relations: (1 occupational dysfunction on stress response (n = 468, (2 occupational dysfunction on burnout syndrome (n = 1,142, and (3 occupational dysfunction on depression (n = 687. Personal characteristics were collected through a questionnaire (such as age, gender, and job category, opportunities for refreshment, time spent on leisure activities, and work relationships as well as the Classification and Assessment of Occupational Dysfunction (CAOD. Furthermore, study 1 included the Stress Response Scale-18 (SRS-18, study 2 used the Japanese Burnout Scale (JBS, and study 3 employed the Center for Epidemiological Studies Depression Scale (CES-D. The Kolmogorov–Smirnov test, confirmatory factor analysis (CFA, exploratory factor analysis (EFA, and path analysis of structural equation modeling (SEM analysis were used in all of the studies. EFA and CFA were used to measure structural validity of four assessments; CAOD, SRS-18, JBS, and CES-D. For examination of a potential covariate, we assessed the correlation of the total and factor score of CAOD and personal factors in all studies. Moreover, direct and indirect effects of occupational dysfunction on stress response (Study 1, burnout syndrome (Study 2, and depression (Study 3 were also analyzed.Results. In study 1, CAOD had 16 items and 4 factors. In Study 2 and 3, CAOD had 16 items and 5 factors. SRS-18 had 18 items and 3 factors, JBS had 17 items and 3 factors, and CES-D had 20 items and 4 factors. All studies found that there were significant correlations between the CAOD total score and the personal factor that included opportunities for refreshment, time spent on leisure

  7. Genetic Structure and Relationship Analysis of an Association Population in Jute (Corchorus spp. Evaluated by SSR Markers.

    Directory of Open Access Journals (Sweden)

    Liwu Zhang

    Full Text Available Population structure and relationship analysis is of great importance in the germplasm utilization and association mapping. Jute, comprised of white jute (C. capsularis L and dark jute (C. olitorius L, is second to cotton in its commercial significance in the world. Here, we assessed the genetic structure and relationship in a panel of 159 jute accessions from 11 countries and regions using 63 SSRs. The structure analysis divided the 159 jute accessions from white and dark jute into Co and Cc group, further into Co1, Co2, Cc1 and Cc2 subgroups. Out of Cc1 subgroup, 81 accessions were from China and the remaining 10 accessions were from India (2, Japan (5, Thailand, Vietnam (2 and Pakistan (1. Out of Cc2 subgroup, 35 accessions were from China, and the remaining 3 accessions were from India, Pakistan and Thailand respectively. It can be inferred that the genetic background of these jute accessions was not always correlative with their geographical regions. Similar results were found in Co1 and Co2 subgroups. Analysis of molecular variance revealed 81% molecular variation between groups but it was low (19% within subgroups, which further confirmed the genetic differentiation between the two groups. The genetic relationship analysis showed that the most diverse genotypes were Maliyeshengchangguo and Changguozhongyueyin in dark jute, BZ-2-2, Aidianyehuangma, Yangjuchiyuanguo, Zijinhuangma and Jute 179 in white jute, which could be used as the potential parents in breeding programs for jute improvement. These results would be very useful for association studies and breeding in jute.

  8. Application of Structural Equations Modeling to assess relationship among Emotional Intelligence, General Health and Occupational Accidents

    OpenAIRE

    MOAMMAD KHANDAN; AMIR KAVOUSI; ALIREZA KOOHPAEI

    2015-01-01

    ORIGINAL ARTICLEEmotional intelligence (EI) has been subject of significant amounts of literature over the past two decades. However, little has been contributed to how emotional intelligence may be practically applied to enhance both accident prevention program and general health in workplaces. Purpose of this paper is to survey relationship among these variables in working society of Iran in 2014. As well as identify practical approaches to application of emotional intelligence skills to ma...

  9. Antiplasmodial Activity, Cytotoxicity and Structure-Activity Relationship Study of Cyclopeptide Alkaloids

    Directory of Open Access Journals (Sweden)

    Emmy Tuenter

    2017-02-01

    Full Text Available Cyclopeptide alkaloids are polyamidic, macrocyclic compounds, containing a 13-, 14-, or 15-membered ring. The ring system consists of a hydroxystyrylamine moiety, an amino acid, and a β-hydroxy amino acid; attached to the ring is a side chain, comprised of one or two more amino acid moieties. In vitro antiplasmodial activity was shown before for several compounds belonging to this class, and in this paper the antiplasmodial and cytotoxic activities of ten more cyclopeptide alkaloids are reported. Combining these results and the IC50 values that were reported by our group previously, a library consisting of 19 cyclopeptide alkaloids was created. A qualitative SAR (structure-activity relationship study indicated that a 13-membered macrocyclic ring is preferable over a 14-membered one. Furthermore, the presence of a β-hydroxy proline moiety could correlate with higher antiplasmodial activity, and methoxylation (or, to a lesser extent, hydroxylation of the styrylamine moiety could be important for displaying antiplasmodial activity. In addition, QSAR (quantitative structure-activity relationship models were developed, using PLS (partial least squares regression and MLR (multiple linear regression. On the one hand, these models allow for the indication of the most important descriptors (molecular properties responsible for the antiplasmodial activity. Additionally, predictions made for interesting structures did not contradict the expectations raised in the qualitative SAR study.

  10. External validation of structure-biodegradation relationship (SBR) models for predicting the biodegradability of xenobiotics.

    Science.gov (United States)

    Devillers, J; Pandard, P; Richard, B

    2013-01-01

    Biodegradation is an important mechanism for eliminating xenobiotics by biotransforming them into simple organic and inorganic products. Faced with the ever growing number of chemicals available on the market, structure-biodegradation relationship (SBR) and quantitative structure-biodegradation relationship (QSBR) models are increasingly used as surrogates of the biodegradation tests. Such models have great potential for a quick and cheap estimation of the biodegradation potential of chemicals. The Estimation Programs Interface (EPI) Suite™ includes different models for predicting the potential aerobic biodegradability of organic substances. They are based on different endpoints, methodologies and/or statistical approaches. Among them, Biowin 5 and 6 appeared the most robust, being derived from the largest biodegradation database with results obtained only from the Ministry of International Trade and Industry (MITI) test. The aim of this study was to assess the predictive performances of these two models from a set of 356 chemicals extracted from notification dossiers including compatible biodegradation data. Another set of molecules with no more than four carbon atoms and substituted by various heteroatoms and/or functional groups was also embodied in the validation exercise. Comparisons were made with the predictions obtained with START (Structural Alerts for Reactivity in Toxtree). Biowin 5 and Biowin 6 gave satisfactorily prediction results except for the prediction of readily degradable chemicals. A consensus model built with Biowin 1 allowed the diminution of this tendency.

  11. Structure-activity relationships between sterols and their thermal stability in oil matrix.

    Science.gov (United States)

    Hu, Yinzhou; Xu, Junli; Huang, Weisu; Zhao, Yajing; Li, Maiquan; Wang, Mengmeng; Zheng, Lufei; Lu, Baiyi

    2018-08-30

    Structure-activity relationships between 20 sterols and their thermal stabilities were studied in a model oil system. All sterol degradations were found to be consistent with a first-order kinetic model with determination of coefficient (R 2 ) higher than 0.9444. The number of double bonds in the sterol structure was negatively correlated with the thermal stability of sterol, whereas the length of the branch chain was positively correlated with the thermal stability of sterol. A quantitative structure-activity relationship (QSAR) model to predict thermal stability of sterol was developed by using partial least squares regression (PLSR) combined with genetic algorithm (GA). A regression model was built with R 2 of 0.806. Almost all sterol degradation constants can be predicted accurately with R 2 of cross-validation equals to 0.680. Four important variables were selected in optimal QSAR model and the selected variables were observed to be related with information indices, RDF descriptors, and 3D-MoRSE descriptors. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Significance of Wheat Flour Dough Rheology to Gas Cell Structure Development in Bread and Other Baked Products

    Science.gov (United States)

    Engmann, Jan

    2008-07-01

    We discuss which rheological material functions of wheat flour dough are most relevant for structure development in baked products under common processing conditions. We consider the growth of gas cells during dough proofing (driven by yeast) and during baking, where the growth is driven by a combination of CO2 desorption, water and ethanol evaporation, and thermal expansion of gas. Attention is given to upper limits on biaxial extension rate and stress and the consequences for the required rheological material functions. The applicability of the "Considère criterion" to predict the probability of coalescence between gas cells and its effect on loaf aeration is briefly discussed.

  13. Processing, structure, property and performance relationships for the thermal spray of the internal surface of aluminum cylinders

    Science.gov (United States)

    Cook, David James

    The increased need for automotive weight reduction has necessitated the use of aluminum for engine blocks. Conventional aluminum alloys cannot survive the constant wear from a piston ring reciprocating on the surface. However, a wear resistant thermal spray coating can be applied on the internal surface of the cylinder bore, which has significant advantages over other available options. Thermal spray is a well-established process for depositing molten, semi-molten, or solid particles onto a substrate to form a protective coating. For this application, the two main challenges were obtaining good wear resistance, and achieving good adhesion. To design a system capable of producing a well-adhered, wear resistant coating for this high volume application it is necessary to identify the overall processing, structure, properties, and performance relationships. The results will demonstrate that very important relationships exist among particle characteristics, substrate conditions, and the properties of the final coating. However, it is the scientific studies to understand some of the process physics in these relationships that allow recognition of the critical processing conditions that need to be controlled to ensure a consistent, reliable thermal spray coating. In this investigation, it will be shown that the critical microstructural aspect of the coating that produced the required tribological properties was the presence of wuestite (FeO). It was found that by using a low carbon steel material with compressed air atomizing gas, it was possible to create an Fe/FeO structure that exhibited excellent tribological properties. This study will also show that traditional thermal spray surface preparation techniques were not ideal for this application, therefore a novel alternative approach was developed. The application of a flux to the aluminum surface prior to thermal spray promotes excellent bond strengths to non-roughened aluminum. Analysis will show that this flux strips

  14. Structures, chemotaxonomic significance, cytotoxic and Na(+),K(+)-ATPase inhibitory activities of new cardenolides from Asclepias curassavica.

    Science.gov (United States)

    Zhang, Rong-Rong; Tian, Hai-Yan; Tan, Ya-Fang; Chung, Tse-Yu; Sun, Xiao-Hui; Xia, Xue; Ye, Wen-Cai; Middleton, David A; Fedosova, Natalya; Esmann, Mikael; Tzen, Jason T C; Jiang, Ren-Wang

    2014-11-28

    Five new cardenolide lactates (1–5) and one new dioxane double linked cardenolide glycoside (17) along with 15 known compounds (6–16 and 18–21) were isolated from the ornamental milkweed Asclepias curassavica. Their structures were elucidated by extensive spectroscopic methods (IR, UV, MS, 1D- and 2D-NMR). The molecular structures and absolute configurations of 1–3 and 17 were further confirmed by single-crystal X-ray diffraction analysis. Simultaneous isolation of dioxane double linked cardenolide glycosides (17–21) and cardenolide lactates (1–5) provided unique chemotaxonomic markers for this genus. Compounds 1–21 were evaluated for the inhibitory activities against DU145 prostate cancer cells. The dioxane double linked cardenolide glycosides showed the most potent cytotoxic effect followed by normal cardenolides and cardenolide lactates, while the C21 steroids were non-cytotoxic. Enzymatic assay established a correlation between the cytotoxic effects in DU145 cancer cells and the Ki for the inhibition of Na(+),K(+)-ATPase. Molecular docking analysis revealed relatively strong H-bond interactions between the bottom of the binding cavity and compounds 18 or 20, and explained why the dioxane double linked cardenolide glycosides possessed higher inhibitory potency on Na(+),K(+)-ATPase than the cardenolide lactate.

  15. Is better beautiful or is beautiful better? Exploring the relationship between beauty and category structure.

    Science.gov (United States)

    Sanders, Megan; Davis, Tyler; Love, Bradley C

    2013-06-01

    We evaluate two competing accounts of the relationship between beauty and category structure. According to the similarity-based view, beauty arises from category structure such that central items are favored due to their increased fluency. In contrast, the theory-based view holds that people's theories of beauty shape their perceptions of categories. In the present study, subjects learned to categorize abstract paintings into meaningfully labeled categories and rated the paintings' beauty, value, and typicality. Inconsistent with the similarity-based view, beauty ratings were highly correlated across conditions despite differences in fluency and assigned category structure. Consistent with the theory-based view, beautiful paintings were treated as central members for categories expected to contain beautiful paintings (e.g., art museum pieces), but not in others (e.g., student show pieces). These results suggest that the beauty of complex, real-world stimuli is not determined by fluency within category structure but, instead, interacts with people's prior knowledge to structure categories.

  16. The relationship between motivational structure, sense of control, intrinsic motivation and university students' alcohol consumption.

    Science.gov (United States)

    Shamloo, Zohreh Sepehri; Cox, W Miles

    2010-02-01

    The aim of this study was to determine how sense of control and intrinsic motivation are related to university students' motivational structure and alcohol consumption. Participants were 94 university students who completed the Personal Concerns Inventory, Shapiro Control Inventory, Helplessness Questionnaire, Intrinsic-Extrinsic Aspirations Scale, and Alcohol Use Questionnaire. Results showed that sense of control and intrinsic motivation were positively correlated with adaptive motivation and negatively correlated with alcohol consumption. Mediational analyses indicated that adaptive motivation fully mediated the relationship between sense of control/intrinsic motivation and alcohol consumption.

  17. Structure activity relationship study of curcumin analogues toward the amyloid-beta aggregation inhibitor.

    Science.gov (United States)

    Endo, Hitoshi; Nikaido, Yuri; Nakadate, Mamiko; Ise, Satomi; Konno, Hiroyuki

    2014-12-15

    Inhibition of the amyloid β aggregation process could possibly prevent the onset of Alzheimer's disease. In this article, we report a structure-activity relationship study of curcumin analogues for anti amyloid β aggregation activity. Compound 7, the ideal amyloid β aggregation inhibitor in vitro among synthesized curcumin analogues, has not only potent anti amyloid β aggregation effects, but also water solubility more than 160 times that of curcumin. In addition, new approaches to improve water solubility of curcumin-type compounds are proposed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Study of the structure-activity relationships of parabens: a practical class

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Joao Paulo dos Santos; Savino, Giovanna; Amarante, Andre Cortinas Goncalves, E-mail: joao.fernandes@mackenzie.br [Centro de Ciencias Biologicas e da Saude, Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil); Sousa, Milena Rodrigues de; Silva, Geane Ramos da [Universidade Camilo Castelo Branco, Sao Paulo, SP (Brazil); Cianciulli, Maria Eliza [Universidade do Grande ABC, Santo Andre, SP (Brazil); Correa, Michelle Fidelis; Ferrarini, Marcio [Centro Universitario Sao Camilo, Sao Paulo, SP (Brazil)

    2013-09-01

    Parabens are p-hydroxybenzoic acid esters widely used as preservatives. With the aim of teaching the structure-activity relationships (SAR) knowledge in a practical form, this paper proposed a practical class to view the SAR of parabens as antimicrobial agents. Methyl, ethyl, n-propyl, isopropyl and isopentyl paraben compounds were synthesized and their respective antimicrobial activities were assessed through determination of minimum inhibitory concentrations (MIC) against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 stains. With the MIC values, it was possible to verify their correlation with calculated lipophilicity (ClogP). This method can be applied in practical Medicinal Chemistry classes. (author)

  19. Quantitative Structure activity relationship and risk analysis of some pesticides in the cattle milk

    OpenAIRE

    Faqir Muhammad*, Ijaz Javed, Masood Akhtar1, Zia-ur-Rahman, Mian Muhammad Awais1, Muhammad Kashif Saleemi2 and Muhammad Irfan Anwar3

    2012-01-01

    Milk of cattle was collected from various localities of Faisalabad, Pakistan. Pesticides concentration was determined by HPLC using solid phase microextraction. The residue analysis revealed that about 40% milk samples were contaminated with pesticides. The mean±SE levels (ppm) of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.38±0.02, 0.26±0.02, 0.072±0.01 and 0.085±0.02, respectively. Quantitative structure activity relationship (QSAR) models were used to predict the residues...

  20. Study of the structure-activity relationships of parabens: a practical class

    International Nuclear Information System (INIS)

    Fernandes, João Paulo dos Santos; Savino, Giovanna; Amarante, André Cortinas Gonçalves; Sousa, Milena Rodrigues de; Silva, Geane Ramos da; Cianciulli, Maria Eliza; Corrêa, Michelle Fidelis; Ferrarini, Márcio

    2013-01-01

    Parabens are p-hydroxybenzoic acid esters widely used as preservatives. With the aim of teaching the structure-activity relationships (SAR) knowledge in a practical form, this paper proposed a practical class to view the SAR of parabens as antimicrobial agents. Methyl, ethyl, n-propyl, isopropyl and isopentyl paraben compounds were synthesized and their respective antimicrobial activities were assessed through determination of minimum inhibitory concentrations (MIC) against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 stains. With the MIC values, it was possible to verify their correlation with calculated lipophilicity (ClogP). This method can be applied in practical Medicinal Chemistry classes. (author)

  1. Structure-antioxidant activity relationships of flavonoids isolated from the resinous exudate of Heliotropium sinuatum.

    Science.gov (United States)

    Modak, Brenda; Contreras, M Leonor; González-Nilo, Fernando; Torres, René

    2005-01-17

    Relationships between the structural characteristics of flavonoids isolated from the resinous exudate of Heliotropium sinuatum and their antioxidant activity were studied. Radical formation energies, DeltaH of dehydrogenation and spin densities were calculated using DFT methods (B3LYP/6-31G*). Results show that studied flavonoids can be divided into two sets according to their activity. It has been found that antioxidant activity depends both on substitution pattern of hydroxyl groups of the flavonoid skeleton and the presence of an unsaturation at the C2-C3 bond. A good tendency between DeltaH of dehydrogenation and antioxidant activity was established.

  2. The global relationship between chromatin physical topology, fractal structure, and gene expression

    DEFF Research Database (Denmark)

    Almassalha, Luay M; Tiwari, A; Ruhoff, P T

    2017-01-01

    in an empty space, but in a highly complex, interrelated, and dense nanoenvironment that profoundly influences chemical interactions. We explored the relationship between the physical nanoenvironment of chromatin and gene transcription in vitro. We analytically show that changes in the fractal dimension, D...... show that the increased heterogeneity of physical structure of chromatin due to increase in fractal dimension correlates with increased heterogeneity of gene networks. These findings indicate that the higher order folding of chromatin topology may act as a molecular-pathway independent code regulating...

  3. Relationship between structure and antiproliferative activity of polymethoxyflavones towards HL60 cells.

    Science.gov (United States)

    Kawaii, Satoru; Ikuina, Tomoyasu; Hikima, Takeshi; Tokiwano, Tetsuo; Yoshizawa, Yuko

    2012-12-01

    As part of our continuing investigation of polymethoxyflavone (PMF) derivatives as potential anticancer substances, a series of PMF derivatives was synthesized. The synthesized compounds were evaluated for cytotoxicity against the promyelocytic leukemic HL60 cell line, and structure-activity relationship correlations were investigated along with previously isolated PMFs from the peel of king orange (Citrus nobilis). 7,3'-Dimethoxyflavone demonstrated the most potent activity among the synthetic PMFs. Consideration of correlation between the methoxylation pattern and antiproliferative activity revealed the importance of the 3'-methoxyl group and the higher degree of methoxylation on the A-ring moiety of PMFs.

  4. Electron-topological investigation of the structure-antitumor activity relationship of thiosemicarbazone derivatives.

    Science.gov (United States)

    Dimoglo, A S; Chumakov, Y M; Dobrova, B N; Saracoglu, M

    1997-04-01

    In the frameworks of the electron-topological method (ETM) the structure-antitumor activity relationship was investigated for a series of thiosemicarbazone derivatives. The series included 70 compounds. Conformational analysis and quantum-chemical calculations were carried out for each compound. The revealed activity feature showed a satisfactory description of the class of active compounds according to two different parameters P and alpha estimating the probabilities of the feature realization in the class of active compounds (they are equal to 0.94 and 0.86, correspondingly). The results of testing demonstrated the high ability of ETM in predicting the activity investigated.

  5. On the relationship between magnetostatic wave energy and dispersion characteristics in ferrite structures

    International Nuclear Information System (INIS)

    Vashkovsky, Anatolii V; Lock, Edwin H

    2011-01-01

    The energy and dispersion characteristics of a dipole spin wave in a ferrite-dielectric-metal structure are calculated. An analysis of spin wave dispersion characteristics with extreme points demonstrates how fundamental relationships among the propagation constant, phase and group velocities, Poynting vector, and power flux manifest themselves when the wavenumber changes near these points. A comparison of magnetostatic approximation results with calculations using Maxwell's equations shows the inadequacy of the magnetostatic approximation formulas currently used for calculating the Poynting vector and power flux of dipole spin waves. A correct alternative is proposed. (methodological notes)

  6. Three-dimensional quantitative structure-activity relationships and docking studies of some structurally diverse flavonoids and design of new aldose reductase inhibitors

    Directory of Open Access Journals (Sweden)

    Utpal Chandra De

    2015-01-01

    Full Text Available Aldose reductase (AR plays an important role in the development of several long-term diabetic complications. Inhibition of AR activities is a strategy for controlling complications arising from chronic diabetes. Several AR inhibitors have been reported in the literature. Flavonoid type compounds are shown to have significant AR inhibition. The objective of this study was to perform a computational work to get an idea about structural insight of flavonoid type compounds for developing as well as for searching new flavonoid based AR inhibitors. The data-set comprising 68 flavones along with their pIC 50 values ranging from 0.44 to 4.59 have been collected from literature. Structure of all the flavonoids were drawn in Chembiodraw Ultra 11.0, converted into corresponding three-dimensional structure, saved as mole file and then imported to maestro project table. Imported ligands were prepared using LigPrep option of maestro 9.6 version. Three-dimensional quantitative structure-activity relationships and docking studies were performed with appropriate options of maestro 9.6 version installed in HP Z820 workstation with CentOS 6.3 (Linux. A model with partial least squares factor 5, standard deviation 0.2482, R 2 = 0.9502 and variance ratio of regression 122 has been found as the best statistical model.

  7. Structural optimization and structure-functional selectivity relationship studies of G protein-biased EP2 receptor agonists.

    Science.gov (United States)

    Ogawa, Seiji; Watanabe, Toshihide; Moriyuki, Kazumi; Goto, Yoshikazu; Yamane, Shinsaku; Watanabe, Akio; Tsuboi, Kazuma; Kinoshita, Atsushi; Okada, Takuya; Takeda, Hiroyuki; Tani, Kousuke; Maruyama, Toru

    2016-05-15

    The modification of the novel G protein-biased EP2 agonist 1 has been investigated to improve its G protein activity and develop a better understanding of its structure-functional selectivity relationship (SFSR). The optimization of the substituents on the phenyl ring of 1, followed by the inversion of the hydroxyl group on the cyclopentane moiety led to compound 9, which showed a 100-fold increase in its G protein activity compared with 1 without any increase in β-arrestin recruitment. Furthermore, SFSR studies revealed that the combination of meta and para substituents on the phenyl moiety was crucial to the functional selectivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Hyoscine butylbromide significantly decreases motion artefacts and allows better delineation of anatomic structures in mp-MRI of the prostate

    Energy Technology Data Exchange (ETDEWEB)

    Ullrich, T.; Quentin, M.; Schmaltz, A.K.; Rubbert, C.; Blondin, D.; Antoch, G.; Schimmoeller, L. [University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany); Arsov, C.; Rabenalt, R.; Albers, P. [University Dusseldorf, Medical Faculty, Department of Urology, Dusseldorf (Germany)

    2018-01-15

    To prospectively evaluate the effect of hyoscine butylbromide (HBB) on visualisation of anatomical details and motion-related artefacts in mp-MRI of the prostate at 3.0 Tesla. One hundred and three consecutive patients (65 ± 10 years) were included in this trial, powered to demonstrate an improvement of image quality after HBB administration, assessed on a 5-point scale by two blinded readers. All patients received high-spatial resolution axial T2-weighted TSE sequences at 3.0 T without spasmolytic agent, repeated after application of 40 mg HBB and followed by routine mp-MRI. Secondary endpoints were (1) susceptibility to side effects, (2) dependence of spasmolytic effect on patients and acute; weight, and (3) prostate volume. In 68% of patients, HBB significantly improved the anatomic score (mean 3.4 ± 0.9 before and 4.4 ± 0.7 after HBB for both readers, p = <0.001). In 67%, HBB significantly enhanced the artefact score (mean 3.2 ± 1 before and 4.2 ± 0.8 after HBB for reader 1, p = <0.001; 3.2 ± 1 and 4.1 ± 0.8 for reader 2, p = <0.001). Subgroup analysis revealed no statistically significant difference between patients with different bodyweight or prostate volume. Inter-reader agreement was excellent (k = 0.95-0.98). Hyoscine butylbromide significantly improves image quality and reduces motion-related artefacts in mp-MRI of the prostate independent of bodyweight or prostate volume. No side effects were reported. (orig.)

  9. Hyoscine butylbromide significantly decreases motion artefacts and allows better delineation of anatomic structures in mp-MRI of the prostate

    International Nuclear Information System (INIS)

    Ullrich, T.; Quentin, M.; Schmaltz, A.K.; Rubbert, C.; Blondin, D.; Antoch, G.; Schimmoeller, L.; Arsov, C.; Rabenalt, R.; Albers, P.

    2018-01-01

    To prospectively evaluate the effect of hyoscine butylbromide (HBB) on visualisation of anatomical details and motion-related artefacts in mp-MRI of the prostate at 3.0 Tesla. One hundred and three consecutive patients (65 ± 10 years) were included in this trial, powered to demonstrate an improvement of image quality after HBB administration, assessed on a 5-point scale by two blinded readers. All patients received high-spatial resolution axial T2-weighted TSE sequences at 3.0 T without spasmolytic agent, repeated after application of 40 mg HBB and followed by routine mp-MRI. Secondary endpoints were (1) susceptibility to side effects, (2) dependence of spasmolytic effect on patients and acute; weight, and (3) prostate volume. In 68% of patients, HBB significantly improved the anatomic score (mean 3.4 ± 0.9 before and 4.4 ± 0.7 after HBB for both readers, p = <0.001). In 67%, HBB significantly enhanced the artefact score (mean 3.2 ± 1 before and 4.2 ± 0.8 after HBB for reader 1, p = <0.001; 3.2 ± 1 and 4.1 ± 0.8 for reader 2, p = <0.001). Subgroup analysis revealed no statistically significant difference between patients with different bodyweight or prostate volume. Inter-reader agreement was excellent (k = 0.95-0.98). Hyoscine butylbromide significantly improves image quality and reduces motion-related artefacts in mp-MRI of the prostate independent of bodyweight or prostate volume. No side effects were reported. (orig.)

  10. Uranium mineralization at Anomaly 2J, South Alligator Valley, Northern Territory, and its significance concerning regional structure and stratigraphy

    International Nuclear Information System (INIS)

    Foy, N.F.; Miezitis, Y.

    1977-01-01

    A weak airborne anomaly was examined in the field and the presence of uranium confirmed. Rotary-percussion drilling showed the presence of uranium but a subsequent programme of diamond and rotary-percussion drilling indicated that the concentration of uranium was uneconomic. Within the tuffs and volcanics of the prospect the uranium existed as uranyl phosphates within the oxidized zone. Geological mapping and the diamond drill core showed that the Stag Creek Volcanics are part of the Lower Proterozoic Masson Formation, probably with member status, rather than the expression of an Archaean basement ridge. This change in the interpretation of the fundamental structure of the Pine Creek Geosyncline has led to a re-examination of the stratigraphy and to suggestions which differ from the current concept. (author)

  11. Structural changes in the knee during weight loss maintenance after a significant weight loss in obese patients with osteoarthritis

    DEFF Research Database (Denmark)

    Henriksen, M; Christensen, R; Hunter, D J

    2014-01-01

    OBJECTIVE: To compare structural knee joint changes in obese patients with knee osteoarthritis (OA) that after an intensive weight loss therapy were randomized to continuous dietetic support, a specialized knee exercise program, or 'no attention' for 1 year. METHODS: 192 obese individuals with knee...... OA underwent an intensive 16-week weight loss program with subsequent randomization to one of the three treatment groups. Changes in cartilage loss, bone marrow lesions (BMLs), synovitis, and effusion were assessed using semi quantitative assessments of magnetic resonance imaging (MRI) obtained...... (difference: -0.21 [95%CI -0.40:-0.03]) and "no attention" (difference: -0.26 [95%CI -0.44:-0.07]) groups. CONCLUSION: In this 1 year follow-up after weight-loss in obese knee OA patients, we found a potentially increased number of BMLs in the exercise group compared to the diet and no attention groups...

  12. Significant effect of substrate temperature on the phase structure, optical and electrical properties of RF sputtered CIGS films

    Energy Technology Data Exchange (ETDEWEB)

    Yu Zhou; Yan Yong; Li Shasha; Zhang Yanxia; Yan Chuanpeng; Liu Lian; Zhang Yong [Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle, Ministry of Education, Superconductivity and New energy R and D Center (SNERDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Zhao Yong, E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle, Ministry of Education, Superconductivity and New energy R and D Center (SNERDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer Secondary phase exist in the RF sputtered CIGS films as it deposited at 150 Degree-Sign C and 500 Degree-Sign C. Black-Right-Pointing-Pointer CIGS films deposited beyond 350 Degree-Sign C show (1 1 2) prefer orientation. Black-Right-Pointing-Pointer E{sub g} of the CIGS films increased with the increase of substrate temperature. Black-Right-Pointing-Pointer Conductivity of the films is affected by 'variable range hopping' mechanism. - Abstract: This work studied the effect of substrate temperature on the phase structure, optical and electrical properties of the one-step radio frequency sputtered Cu(In,Ga)Se{sub 2} (CIGS) thin films. X-ray diffraction (XRD) analysis revealed that all the deposited CIGS films are chalcopyrite phase with polycrystalline structure. The films deposited beyond the substrate temperature of 350 Degree-Sign C show (1 1 2) prefer orientation. Raman spectra reveal that the 150 Degree-Sign C deposited CIGS film coexists with Cu{sub 2-x}Se phase and the 500 Degree-Sign C deposited film contains ordered defect compound (ODC) phase. With the increase of substrate temperature, energy band gap of the CIGS film increase from 0.99 to 1.27 eV. Films deposited at higher temperature exhibit larger electrical conductivity. Conductivity of the CIGS films is dominated by 'variable range hopping' mechanism. The disorder in our CIGS the films is associated with the formation of intrinsic defects such as V{sub Se} and In{sub Cu} for their low formation energy.

  13. Comparison of Macular Integrity Assessment (MAIA ™, MP-3, and the Humphrey Field Analyzer in the Evaluation of the Relationship between the Structure and Function of the Macula.

    Directory of Open Access Journals (Sweden)

    Kazuyuki Hirooka

    Full Text Available This study was conducted in order to compare relationships between the macular visual field (VF mean sensitivity measured by MAIATM (Macular Integrity Assessment, MP-3, or Humphry field analyzer (HFA and the ganglion cell and inner plexiform layer (GCA thicknesses.This cross-sectional study examined 73 glaucoma patients and 19 normal subjects. All subjects underwent measurements for GCA thickness by Cirrus HD-OCT and static threshold perimetry using MAIATM, MP-3, or HFA. VF and OCT in the retinal view were used to examine both the global relationship between the VF sensitivity and GCA thickness, and the superior hemiretina and inferior hemiretina. The relationship between the GCA thickness and macular sensitivity was examined by Spearman correlation analysis.For each instrument, statistically significant macular VF sensitivity (dB and GCA thickness relationships were observed using the decibel scale (R = 0.547-0.687, all P < 0.001. The highest correlation for the global (R = 0.682 and the superior hemiretina (R = 0.594 GCA thickness-VF mean sensitivity was observed by the HFA. The highest correlation for the inferior hemiretina (R = 0.687 GCA thickness-VF mean sensitivity was observed by the MP-3. Among the three VF measurement instruments, however, no significant differences were found for the structure-function relationships.All three VF measurement instruments found similar structure-function relationships in the central VF.

  14. Significance of performing CT after radiofrequency ablation of hepatocellular carcinoma. Relationship between CT findings in areas other than the tumor site and post therapeutic outcome

    International Nuclear Information System (INIS)

    Shimokoube, Kouichi; Saito, Kazuhiro; Kotake, Fumio; Nakamura, Hiroshi; Mizokami, Yuji; Mikami, Ryuji; Matsuoka, Takeshi

    2004-01-01

    The relationships between the CT findings following radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) and the clinical symptoms and laboratory data were examined. The subjects consisted of 31 cases (41 nodules) of HCC that were treated by RFA. The CT findings before and after RFA, particularly the findings in areas other than the treatment site (henceforth, secondary findings), were evaluated by a physician and a radiologist. In addition, the relationships between the CT findings and post-RFA clinical symptoms (fever/pain) and laboratory data were examined. Secondary findings were found in 90.3% (28/31). These findings were broadly classified into changes in the needle tract 51.6% (16/31), retention of effusion 41.9% (13/31), thickening of the gallbladder wall 12.9% (4/31), changes in the retroperitoneal space 9.7% (3/31), and dilatation of the intrahepatic bile duct 3.2% (1/31), in the order of frequency. A relationship was found between changes in the retroperitoneal space and the clinical symptoms (fever: p=0.0366, pain: p=0.0012). Relationships were also found between changes in the needle tract and retention of effusion and aspartate aminotransferase (AST) (p<0.0001), as well as between changes in the needle tract and alanine aminotransferase (ALT) (p=0.0149). The size of the treatment area did not correlate with the presence of clinical symptoms and changes in laboratory data. Diverse classification of CT findings was observed after RFA, and a relationship with clinical symptoms was noted. A relationship was also found between classification of the CT findings following RFA and the post-therapeutic outcome. (authors)

  15. A phenomenological model for the structure-composition relationship of the high Tc cuprates based on simple chemical principles

    International Nuclear Information System (INIS)

    Alarco, J.A.; Talbot, P.C.

    2012-01-01

    A simple phenomenological model for the relationship between structure and composition of the high Tc cuprates is presented. The model is based on two simple crystal chemistry principles: unit cell doping and charge balance within unit cells. These principles are inspired by key experimental observations of how the materials accommodate large deviations from stoichiometry. Consistent explanations for significant HTSC properties can be explained without any additional assumptions while retaining valuable insight for geometric interpretation. Combining these two chemical principles with a review of Crystal Field Theory (CFT) or Ligand Field Theory (LFT), it becomes clear that the two oxidation states in the conduction planes (typically d 8 and d 9 ) belong to the most strongly divergent d-levels as a function of deformation from regular octahedral coordination. This observation offers a link to a range of coupling effects relating vibrations and spin waves through application of Hund’s rules. An indication of this model’s capacity to predict physical properties for HTSC is provided and will be elaborated in subsequent publications. Simple criteria for the relationship between structure and composition in HTSC systems may guide chemical syntheses within new material systems.

  16. Anosognosia in mild cognitive impairment: Relationship to activation of cortical midline structures involved in self-appraisal

    Science.gov (United States)

    Ries, Michele L.; Jabbar, Britta M.; Schmitz, Taylor W.; Trivedi, Mehul A.; Gleason, Carey E.; Carlsson, Cynthia M.; Rowley, Howard A.; Asthana, Sanjay; Johnson, Sterling C.

    2009-01-01

    Awareness of cognitive dysfunction shown by individuals with Mild Cognitive Impairment (MCI), a condition conferring risk for Alzheimer’s disease (AD), is variable. Anosognosia, or unawareness of loss of function, is beginning to be recognized as an important clinical symptom of MCI. However, little is known about the brain substrates underlying this symptom. We hypothesized that MCI participants’ activation of cortical midline structures (CMS) during self-appraisal would covary with level of insight into cognitive difficulties (indexed by a discrepancy score between patient and informant ratings of cognitive decline in each MCI participant). To address this hypothesis, we first compared 16 MCI participants and 16 age-matched controls, examining brain regions showing conjoint or differential BOLD response during self-appraisal. Second, we used regression to investigate the relationship between awareness of deficit in MCI and BOLD activity during self-appraisal, controlling for extent of memory impairment. Between-group comparisons indicated that MCI participants show subtly attenuated CMS activity during self-appraisal. Regression analysis revealed a highly-significant relationship between BOLD response during self-appraisal and self-awareness of deficit in MCI. This finding highlights the level of anosognosia in MCI as an important predictor of response to self-appraisal in cortical midline structures, brain regions vulnerable to changes in early AD. PMID:17445294

  17. Preliminary analysis of the relationship between structure and anthelmintic activity of condensed tannins in cattle nemaotdes

    DEFF Research Database (Denmark)

    Desrues, Olivier; Larsen Enemark, Heidi; Mueller-Harvey, Irene

    2013-01-01

    Some plant secondary metabolites as tannins have direct anthelminthic properties and may play a role in the control of nematodes in livestock. However, their great diversity in structural characteristics and different levels of content in plants are responsible for a highly variable response...... in anthelmintic activity, as measured in vitro. The aim of the present study was to assess the relationship between structure and anthelmintic activity using an in vitro assay. We used a series of purified tannins (from 65% to 100% of purity) characterized for their degree of polymerization (mDP), prodelphinidin....../procyanidin ratio and cis/trans ratio by thiolytic degradation. Tannins diluted in two concentrations in water, epigallocatechin gallate, positive (ivermectin) and negative (water) controls were examined by the Larval Feeding Inhibition Assay (LFIA) with first stage larvae (L1) of the cattle nematode Cooperia...

  18. Preliminary analysis of the relationship between structure and anthelmintic activity of condensed tannins in cattle nematodes

    DEFF Research Database (Denmark)

    Desrues, Oliver; Enemark, Heidi L.; Mueller-Harvey, I.

    2013-01-01

    Some plant secondary metabolites as tannins have direct anthelminthic properties and may play a role in the control of nematodes in livestock. However, their great diversity in structural characteristics and different levels of content in plants are responsible for a highly variable response...... in anthelmintic activity, as measured in vitro. The aim of the present study was to assess the relationship between tannin structure and anthelmintic activity using an in vitro assay. We used a series of purified tannins (from 65% to 100% of purity) characterized for their degree of polymerization (m......DP), prodelphinidin/procyanidin (PC/PD) ratio and cis/trans ratio by thiolytic degradation. Tannins diluted in two concentrations in water, epigallocatechin gallate (EGCG), positive (ivermectin) and negative (water) controls were examined by the Larval Feeding Inhibition Assay (LFIA) with first stage larvae (L1...

  19. QUANTITATIVE ELECTRONIC STRUCTURE - ACTIVITY RELATIONSHIP OF ANTIMALARIAL COMPOUND OF ARTEMISININ DERIVATIVES USING PRINCIPAL COMPONENT REGRESSION APPROACH

    Directory of Open Access Journals (Sweden)

    Paul Robert Martin Werfette

    2010-06-01

    Full Text Available Analysis of quantitative structure - activity relationship (QSAR for a series of antimalarial compound artemisinin derivatives has been done using principal component regression. The descriptors for QSAR study were representation of electronic structure i.e. atomic net charges of the artemisinin skeleton calculated by AM1 semi-empirical method. The antimalarial activity of the compound was expressed in log 1/IC50 which is an experimental data. The main purpose of the principal component analysis approach is to transform a large data set of atomic net charges to simplify into a data set which known as latent variables. The best QSAR equation to analyze of log 1/IC50 can be obtained from the regression method as a linear function of several latent variables i.e. x1, x2, x3, x4 and x5. The best QSAR model is expressed in the following equation,  (;;   Keywords: QSAR, antimalarial, artemisinin, principal component regression

  20. STRUCTURE-ACTIVITY RELATIONSHIP STUDY OF DITERPENES FOR TREATMENT OF ALZHEIMER'S DISEASE

    Directory of Open Access Journals (Sweden)

    Gabriel F. dos Santos

    Full Text Available Alzheimer's disease is an irreversible, degenerative and age-related disease which is growing more and more with the increase in life expectancy. Kaurane diterpenes are a class of natural products available in large amounts in nature and isolated from plants grown worldwide. In the present work¸ twenty-seven kaurane diterpenes of natural origin and some readily available derivatives were assayed for acetylcholinesterase inhibition and the structure-activity relationship was analyzed. The kaurenoic acid derivatives screened showed to be promising inhibitors of AChE, which could provide new leads for drugs to fight Alzheimer's disease symptoms. Among them, eleven compounds showed activities comparable or higher than the positive control galantamine. Existence of an allylic hydroxyl group showed to be an important structural feature for AChE inhibition. In addition, presence of free hydroxyl groups at C-17 and C-19, furnished a diol especially active, able to completely inhibit AChE.

  1. Structure-Property Relationships in Polymer Derived Amorphous/Nano-Crystalline Silicon Carbide for Nuclear Applications

    International Nuclear Information System (INIS)

    Zunjarrao, Suraj C.; Singh, Abhishek K.; Singh, Raman P.

    2006-01-01

    difficulties in interpreting 'true' properties from bulk measurements. Hence, hardness and modulus measurements are carried out using instrumented nano-indentation to establish property--structure relationship for SiC derived from the polymer precursor. It is seen that the presence of nanocrystalline domains in amorphous SiC significantly influences the modulus and hardness. (authors)

  2. Formation of cognitive structures in conditioned-reflex behavior in monkeys: Relationship with type of visual information.

    Science.gov (United States)

    Dudkin, K N; Chueva, I V

    2009-02-01

    The characteristics of learning processes and long-term memory (LTM) were studied in rhesus macaques discriminating visual stimuli (geometrical figures of different shapes, sizes, and orientations, and with different spatial relationships between image components). Trained monkeys were tested for the ability to perform invariant recognition after stimulus transformation, i.e., changes in size, shape, number of objects, and spatial relationships. Analysis of behavioral characteristics (correct solutions, refusals to decide, motor response times) revealed differences associated with the type of visual information. When monkeys discriminated between black and white geometrical figures of different shapes and orientations, as well as black-and-white figures with different shapes or orientations, the learning time was short and transformation of the stimuli had no effect on correct solutions: there was complete transfer of learning. When monkeys discriminated figures of different sizes or complex images with different spatial relationships, the learning time was significantly greater. Changes in the size and shape of figures led to significant reductions in correct solutions and significant increases in refusals to solve the task and in motor reaction times. Invariance of discrimination in this case appeared after additional training. The results obtained here showed that in conditioned reflex learning, the sensory processing of stimuli has the result that discriminatory features are formed in LTM, i.e., cognitive structures (functional neurophysiological mechanisms), these supporting the classification of visual images. The temporal conditioned link of the executive reaction is established with these. Their formation is determined by the type of sensory information and the existence in LTM of separate subsystems for spatial and non-spatial information.

  3. Quantitative structure-retention relationships of flavonoids unraveled by immobilized artificial membrane chromatography.

    Science.gov (United States)

    Santoro, Adriana Leandra; Carrilho, Emanuel; Lanças, Fernando Mauro; Montanari, Carlos Alberto

    2016-06-10

    The pharmacokinetic properties of flavonoids with differing degrees of lipophilicity were investigated using immobilized artificial membranes (IAMs) as the stationary phase in high performance liquid chromatography (HPLC). For each flavonoid compound, we investigated whether the type of column used affected the correlation between the retention factors and the calculated octanol/water partition (log Poct). Three-dimensional (3D) molecular descriptors were calculated from the molecular structure of each compound using i) VolSurf software, ii) the GRID method (computational procedure for determining energetically favorable binding sites in molecules of known structure using a probe for calculating the 3D molecular interaction fields, between the probe and the molecule), and iii) the relationship between partition and molecular structure, analyzed in terms of physicochemical descriptors. The VolSurf built-in Caco-2 model was used to estimate compound permeability. The extent to which the datasets obtained from different columns differ both from each other and from both the calculated log Poct and the predicted permeability in Caco-2 cells was examined by principal component analysis (PCA). The immobilized membrane partition coefficients (kIAM) were analyzed using molecular descriptors in partial least square regression (PLS) and a quantitative structure-retention relationship was generated for the chromatographic retention in the cholesterol column. The cholesterol column provided the best correlation with the permeability predicted by the Caco-2 cell model and a good fit model with great prediction power was obtained for its retention data (R(2)=0.96 and Q(2)=0.85 with four latent variables). Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Investor structure and the price-volume relationship in a continuous double auction market: An agent-based modeling perspective

    Science.gov (United States)

    Zhang, Wei; Bi, Zhengzheng; Shen, Dehua

    2017-02-01

    This paper investigates the impact of investor structure on the price-volume relationship by simulating a continuous double auction market. Connected with the underlying mechanisms of the price-volume relationship, i.e., the Mixture of Distribution Hypothesis (MDH) and the Sequential Information Arrival Hypothesis (SIAH), the simulation results show that: (1) there exists a strong lead-lag relationship between the return volatility and trading volume when the number of informed investors is close to the number of uninformed investors in the market; (2) as more and more informed investors entering the market, the lead-lag relationship becomes weaker and weaker, while the contemporaneous relationship between the return volatility and trading volume becomes more prominent; (3) when the informed investors are in absolute majority, the market can achieve the new equilibrium immediately. Therefore, we can conclude that the investor structure is a key factor in affecting the price-volume relationship.

  5. Quantitative structure-property relationship (correlation analysis) of phosphonic acid-based chelates in design of MRI contrast agent.

    Science.gov (United States)

    Tiwari, Anjani K; Ojha, Himanshu; Kaul, Ankur; Dutta, Anupama; Srivastava, Pooja; Shukla, Gauri; Srivastava, Rakesh; Mishra, Anil K

    2009-07-01

    Nuclear magnetic resonance imaging is a very useful tool in modern medical diagnostics, especially when gadolinium (III)-based contrast agents are administered to the patient with the aim of increasing the image contrast between normal and diseased tissues. With the use of soft modelling techniques such as quantitative structure-activity relationship/quantitative structure-property relationship after a suitable description of their molecular structure, we have studied a series of phosphonic acid for designing new MRI contrast agent. Quantitative structure-property relationship studies with multiple linear regression analysis were applied to find correlation between different calculated molecular descriptors of the phosphonic acid-based chelating agent and their stability constants. The final quantitative structure-property relationship mathematical models were found as--quantitative structure-property relationship Model for phosphonic acid series (Model 1)--log K(ML) = {5.00243(+/-0.7102)}- MR {0.0263(+/-0.540)}n = 12 l r l = 0.942 s = 0.183 F = 99.165 quantitative structure-property relationship Model for phosphonic acid series (Model 2)--log K(ML) = {5.06280(+/-0.3418)}- MR {0.0252(+/- .198)}n = 12 l r l = 0.956 s = 0.186 F = 99.256.

  6. The Significance of Social Relationships in Learning to Become a Vocational and Technical Education Teacher: A Case Study of Three Individuals

    Science.gov (United States)

    Goh, Adeline Yuen Sze

    2013-01-01

    This article about workplace learning examines the learning of individuals in becoming a Vocational and Technical Education (VTE) teacher in Brunei. Drawing on research findings from a group of student teachers, it presents case study accounts of three individuals to illustrate the importance of social relationships in learning to become a VTE…

  7. The Relationship between Structural Dimensions of Personality and School Life in Adolescence

    Directory of Open Access Journals (Sweden)

    Renato G. Carvalho

    2014-01-01

    Full Text Available In this cross-sectional study, we analyse the relationship between personality, which was operationalized in the PSY-5 dimensions of the Minnesota Multiphasic Personality Inventory - Adolescent (MMPI-A and the way students live their lives at school, expressed through indicators of achievement, integration, and overall satisfaction. A total of 351 students, aged 14-18 years, participated in the study. The instruments were the Portuguese version of the MMPI-A and the School Life Questionnaire. Results show a pattern of significant relationships between personality traits and school life, being Disconstraint and Introversion the personality dimensions that stood out mostly in the explanation of school life variables results. Results are analysed considering the importance of personality for the development of more or less adaptive pathways in adolescence.

  8. ANALYSIS OF SPATIAL STRUCTURE AND SOCIAL SIGNIFICANCE OF A SAMPLE OF HAMMĀMS IN MEDITERRANEAN CITIES

    Directory of Open Access Journals (Sweden)

    Roula Aboukhater

    2008-11-01

    Full Text Available The hammām is a public building which is traditionally closely linked to socio cultural norms of the society that is supposed to serve. This paper seeks to answer questions about the logic by which such buildings respond to those complex socio cultural relations and the potentials offered by their spatial structures. The hypothesis in analyzing the internal layout is based on the ability of forms to adapt to socio cultural norms of certain societies and that they could be shaped to respond to social needs and to produce appropriate behavior. This study is based on the analysis of the morphological characteristics of the internal layouts of several hammāms, the socio-historical information, the direct observation of the spaces and face to face interviews with staff especially those working in hammām Ammuna in Damascus. The main objective is to explore the following questions: 1 How are hammāms “designed” to fulfi ll users’ social needs and their well-being in the internal spaces? 2 How architectural settings in the internal spaces of the hammām are “coded” or “structured” to produce appropriate social practice or behavior? This paper demonstrates that hammāms are the witnesses of a genius locus of adaptation of a building to sociocultural norms.

  9. Evaluation of potential relationships between benthic community structure and toxic metals in Laizhou Bay.

    Science.gov (United States)

    Wu, Bin; Song, Jinming; Li, Xuegang

    2014-10-15

    The objective of the present study was to examine the relationships between benthic community structure and toxic metals using bivariate/multivariate techniques at 17 sediment locations in Laizhou Bay, North China. Sediment chemical data were evaluated against geochemical background values and sediment quality guidelines, which identified Cu and As as contaminants of concern with a moderate potential for adverse effects. Benthic community data were subjected to non-metric multidimensional scaling, which generated four groups of stations. Spearman rank correlation was then employed to explore the relationships between the major axes of heavy metals and benthic community structure. However, weak and insignificant correlations were found between these axes, indicating that contaminants of concern may not be the primary explanatory factors. Polychaeta were abundant in southern Laizhou Bay, serving as a warning regarding the health status of the ecosystem. Integrated sediment quality assessment showed sediments from northern central locations were impaired, displaying less diverse benthos and higher metal contamination. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Using quantitative structure-activity relationships (QSAR) to predict toxic endpoints for polycyclic aromatic hydrocarbons (PAH).

    Science.gov (United States)

    Bruce, Erica D; Autenrieth, Robin L; Burghardt, Robert C; Donnelly, K C; McDonald, Thomas J

    2008-01-01

    Quantitative structure-activity relationships (QSAR) offer a reliable, cost-effective alternative to the time, money, and animal lives necessary to determine chemical toxicity by traditional methods. Additionally, humans are exposed to tens of thousands of chemicals in their lifetimes, necessitating the determination of chemical toxicity and screening for those posing the greatest risk to human health. This study developed models to predict toxic endpoints for three bioassays specific to several stages of carcinogenesis. The ethoxyresorufin O-deethylase assay (EROD), the Salmonella/microsome assay, and a gap junction intercellular communication (GJIC) assay were chosen for their ability to measure toxic endpoints specific to activation-, induction-, and promotion-related effects of polycyclic aromatic hydrocarbons (PAH). Shape-electronic, spatial, information content, and topological descriptors proved to be important descriptors in predicting the toxicity of PAH in these bioassays. Bioassay-based toxic equivalency factors (TEF(B)) were developed for several PAH using the quantitative structure-toxicity relationships (QSTR) developed. Predicting toxicity for a specific PAH compound, such as a bioassay-based potential potency (PP(B)) or a TEF(B), is possible by combining the predicted behavior from the QSTR models. These toxicity estimates may then be incorporated into a risk assessment for compounds that lack toxicity data. Accurate toxicity predictions are made by examining each type of endpoint important to the process of carcinogenicity, and a clearer understanding between composition and toxicity can be obtained.

  11. Quantitative structure-activity relationship (QSAR) for insecticides: development of predictive in vivo insecticide activity models.

    Science.gov (United States)

    Naik, P K; Singh, T; Singh, H

    2009-07-01

    Quantitative structure-activity relationship (QSAR) analyses were performed independently on data sets belonging to two groups of insecticides, namely the organophosphates and carbamates. Several types of descriptors including topological, spatial, thermodynamic, information content, lead likeness and E-state indices were used to derive quantitative relationships between insecticide activities and structural properties of chemicals. A systematic search approach based on missing value, zero value, simple correlation and multi-collinearity tests as well as the use of a genetic algorithm allowed the optimal selection of the descriptors used to generate the models. The QSAR models developed for both organophosphate and carbamate groups revealed good predictability with r(2) values of 0.949 and 0.838 as well as [image omitted] values of 0.890 and 0.765, respectively. In addition, a linear correlation was observed between the predicted and experimental LD(50) values for the test set data with r(2) of 0.871 and 0.788 for both the organophosphate and carbamate groups, indicating that the prediction accuracy of the QSAR models was acceptable. The models were also tested successfully from external validation criteria. QSAR models developed in this study should help further design of novel potent insecticides.

  12. Structural Characterization and Evaluation of the Antioxidant Activity of Phenolic Compounds from Astragalus taipaishanensis and Their Structure-Activity Relationship

    Science.gov (United States)

    Pu, Wenjun; Wang, Dongmei; Zhou, Dan

    2015-09-01

    Eight phenolic compounds were isolated using bio-guided isolation and purified from the roots of Astragalus taipaishanensis Y. C. Ho et S. B. Ho (A. taipaishanensis) for the first time. Their structures were elucidated by ESI-MS, HR-ESI-MS, 1D-NMR and 2D-NMR as 7,2‧-dihydroxy-3‧,4‧-dimethoxy isoflavan (1), formononetin (2), isoliquiritigenin (3), quercetin (4), kaempferol (5), ononin (6), p-hydroxybenzoic acid (7) and vanillic acid (8). Six flavonoids (compounds 1-6) exhibited stronger antioxidant activities (determined by DPPH, ABTS, FRAP and lipid peroxidation inhibition assays) than those of BHA and TBHQ and also demonstrated noticeable protective effects (particularly quercetin and kaempferol) on Escherichia coli under oxidative stress. Additionally, the chemical constituents compared with those of Astragalus membranaceus and the structure-activity relationship of the isolated compounds were both analyzed. The results clearly demonstrated that A. taipaishanensis has the potential to be selected as an alternative medicinal and food plant that can be utilized in health food products, functional tea and pharmaceutical products.

  13. Probing the Unique Role of Gallium in Amorphous Oxide Semiconductors through Structure-Property Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Moffitt, Stephanie L.; Zhu, Qimin; Ma, Qing; Falduto, Allison F.; Buchholz, D. Bruce; Chang, Robert P.H.; Mason, Thomas O.; Medvedeva, Julia E.; Marks, Tobin J.; Bedzyk, Michael J. (NWU); (MUST)

    2017-09-01

    This study explores the unique role of Ga in amorphous (a-) In[BOND]Ga[BOND]O oxide semiconductors through combined theory and experiment. It reveals substitutional effects that have not previously been attributed to Ga, and that are investigated by examining how Ga influences structure–property relationships in a series of pulsed laser deposited a-In[BOND]Ga[BOND]O thin films. Element-specific structural studies (X-ray absorption and anomalous scattering) show good agreement with the results of ab initio molecular dynamics simulations. This structural knowledge is used to understand the results of air-annealing and Hall effect electrical measurements. The crystallization temperature of a-IO is shown to increase by as much as 325 °C on substituting Ga for In. This increased thermal stability is understood on the basis of the large changes in local structure that Ga undergoes, as compared to In, during crystallization. Hall measurements reveal an initial sharp drop in both carrier concentration and mobility with increasing Ga incorporation, which moderates at >20 at% Ga content. This decline in both the carrier concentration and mobility with increasing Ga is attributed to dilution of the charge-carrying In[BOND]O matrix and to increased structural disorder. The latter effect saturates at high at% Ga.

  14. Relationship between Molecular Structure Characteristics of Feed Proteins and Protein In vitro Digestibility and Solubility.

    Science.gov (United States)

    Bai, Mingmei; Qin, Guixin; Sun, Zewei; Long, Guohui

    2016-08-01

    The nutritional value of feed proteins and their utilization by livestock are related not only to the chemical composition but also to the structure of feed proteins, but few studies thus far have investigated the relationship between the structure of feed proteins and their solubility as well as digestibility in monogastric animals. To address this question we analyzed soybean meal, fish meal, corn distiller's dried grains with solubles, corn gluten meal, and feather meal by Fourier transform infrared (FTIR) spectroscopy to determine the protein molecular spectral band characteristics for amides I and II as well as α-helices and β-sheets and their ratios. Protein solubility and in vitro digestibility were measured with the Kjeldahl method using 0.2% KOH solution and the pepsin-pancreatin two-step enzymatic method, respectively. We found that all measured spectral band intensities (height and area) of feed proteins were correlated with their the in vitro digestibility and solubility (p≤0.003); moreover, the relatively quantitative amounts of α-helices, random coils, and α-helix to β-sheet ratio in protein secondary structures were positively correlated with protein in vitro digestibility and solubility (p≤0.004). On the other hand, the percentage of β-sheet structures was negatively correlated with protein in vitro digestibility (pdigestibility at 28 h and solubility. Furthermore, the α-helix-to-β-sheet ratio can be used to predict the nutritional value of feed proteins.

  15. Structurally-constrained relationships between cognitive states in the human brain.

    Directory of Open Access Journals (Sweden)

    Ann M Hermundstad

    2014-05-01

    Full Text Available The anatomical connectivity of the human brain supports diverse patterns of correlated neural activity that are thought to underlie cognitive function. In a manner sensitive to underlying structural brain architecture, we examine the extent to which such patterns of correlated activity systematically vary across cognitive states. Anatomical white matter connectivity is compared with functional correlations in neural activity measured via blood oxygen level dependent (BOLD signals. Functional connectivity is separately measured at rest, during an attention task, and during a memory task. We assess these structural and functional measures within previously-identified resting-state functional networks, denoted task-positive and task-negative networks, that have been independently shown to be strongly anticorrelated at rest but also involve regions of the brain that routinely increase and decrease in activity during task-driven processes. We find that the density of anatomical connections within and between task-positive and task-negative networks is differentially related to strong, task-dependent correlations in neural activity. The space mapped out by the observed structure-function relationships is used to define a quantitative measure of separation between resting, attention, and memory states. We find that the degree of separation between states is related to both general measures of behavioral performance and relative differences in task-specific measures of attention versus memory performance. These findings suggest that the observed separation between cognitive states reflects underlying organizational principles of human brain structure and function.

  16. Highlighting the Structure-Function Relationship of the Brain with the Ising Model and Graph Theory

    Directory of Open Access Journals (Sweden)

    T. K. Das

    2014-01-01

    Full Text Available With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model or global dynamics (e.g., the Ising model have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions.

  17. Structure/property relationships in polymer membranes for water purification and energy applications

    Science.gov (United States)

    Geise, Geoffrey

    Providing sustainable supplies of purified water and energy is a critical global challenge for the future, and polymer membranes will play a key role in addressing these clear and pressing global needs for water and energy. Polymer membrane-based processes dominate the desalination market, and polymer membranes are crucial components in several rapidly developing power generation and storage applications that rely on membranes to control rates of water and/or ion transport. Much remains unknown about the influence of polymer structure on intrinsic water and ion transport properties, and these relationships must be developed to design next generation polymer membrane materials. For desalination applications, polymers with simultaneously high water permeability and low salt permeability are desirable in order to prepare selective membranes that can efficiently desalinate water, and a tradeoff relationship between water/salt selectivity and water permeability suggests that attempts to prepare such materials should rely on approaches that do more than simply vary polymer free volume. One strategy is to functionalize hydrocarbon polymers with fixed charge groups that can ionize upon exposure to water, and the presence of charged groups in the polymer influences transport properties. Additionally, in many emerging energy applications, charged polymers are exposed to ions that are very different from sodium and chloride. Specific ion effects have been observed in charged polymers, and these effects must be understood to prepare charged polymers that will enable emerging energy technologies. This presentation discusses research aimed at further understanding fundamental structure/property relationships that govern water and ion transport in charged polymer films considered for desalination and electric potential field-driven applications that can help address global needs for clean water and energy.

  18. Significance of settling model structures and parameter subsets in modelling WWTPs under wet-weather flow and filamentous bulking conditions

    DEFF Research Database (Denmark)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen

    2014-01-01

    Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks...... (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of ideal and non-ideal flow (dry and wet weather) and settling (good settling and bulking) boundary conditions on the sensitivity of WWTP model outputs to uncertainties intrinsic to the one-dimensional (1-D...... of settling parameters to the total variance of the key WWTP process outputs significantly depends on the influent flow and settling conditions. The magnitude of the impact is found to vary, depending on which type of 1-D SST model is used. Therefore, we identify and recommend potential parameter subsets...

  19. Quantitative structure-activity relationship modeling on in vitro endocrine effects and metabolic stability involving 26 selected brominated flame retardants

    NARCIS (Netherlands)

    Harju, M.; Hamers, T.; Kamstra, J.H.; Sonneveld, E.; Boon, J.P.

    2007-01-01

    In this work, quantitative structure-activity relationships (QSARs) were developed to aid human and environmental risk assessment processes for brominated flame retardants (BFRs). Brominated flame retardants, such as the high-production-volume chemicals polybrominated diphenyl ethers (PBDEs),

  20. A structural equation model of the relationship between insomnia, negative affect, and paranoid thinking.

    Directory of Open Access Journals (Sweden)

    Alexander J Scott

    Full Text Available A growing body of evidence points to relationships between insomnia, negative affect, and paranoid thinking. However, studies are needed to examine (i whether negative affect mediates the relation between insomnia and paranoid thinking, (ii whether different types of insomnia exert different effects on paranoia, and (iii to compare the impact of objective and self-reported sleeping difficulties.Structural equation modelling was therefore used to test competing models of the relationships between self-reported insomnia, negative affect, and paranoia. n = 348 participants completed measures of insomnia, negative affect and paranoia. A subset of these participants (n = 91 went on to monitor their sleep objectively (using a portable sleep monitor made by Zeo for seven consecutive nights. Associations between objectively recorded sleep, negative affect, and paranoia were explored using linear regression.The findings supported a fully mediated model where self-reported delayed sleep onset, but not self-reported problems with sleep maintenance or objective measures of sleep, was directly associated with negative affect that, in turn, was associated with paranoia. There was no evidence of a direct association between delayed sleep onset or sleep maintenance problems and paranoia.Taken together, the findings point to an association between perceived (but not objective difficulties initially falling asleep (but not maintaining sleep and paranoid thinking; a relationship that is fully mediated by negative affect. Future research should seek to disentangle the causal relationships between sleep, negative affect, and paranoia (e.g., by examining the effect of an intervention using prospective designs that incorporate experience sampling. Indeed, interventions might profitably target (i perceived sleep quality, (ii sleep onset, and / or (iii emotion regulation as a route to reducing negative affect and, thus, paranoid thinking.

  1. Perceived Social Relationships and Science Learning Outcomes for Taiwanese Eighth Graders: Structural Equation Modeling with a Complex Sampling Consideration

    Science.gov (United States)

    Jen, Tsung-Hau; Lee, Che-Di; Chien, Chin-Lung; Hsu, Ying-Shao; Chen, Kuan-Ming

    2013-01-01

    Based on the Trends in International Mathematics and Science Study 2007 study and a follow-up national survey, data for 3,901 Taiwanese grade 8 students were analyzed using structural equation modeling to confirm a social-relation-based affection-driven model (SRAM). SRAM hypothesized relationships among students' perceived social relationships in…

  2. Absorbability, Mechanism and Structure-Property Relationship of Three Phenolic Acids from the Flowers of Trollius chinensis

    Directory of Open Access Journals (Sweden)

    Xiu-Wen Wu

    2014-11-01

    Full Text Available The absorption properties, mechanism of action, and structure-property relationship of three phenolic acids isolated from the flowers of Trollius chinensis Bunge, namely, proglobeflowery acid (PA, globeflowery acid (GA and trolloside (TS, were investigated using the human Caco-2 cell monolayer model. The results showed that these three phenolic acids were transported across the Caco-2 cell monolayer in a time and concentration dependent manner at the Papp level of 10−5 cm/s, and their extent of absorption correlated with their polarity and molecular weight. In conclusion, all three of these compounds were easily absorbed through passive diffusion, which implied their high bioavailability and significant contribution to the effectiveness of T. chinensis.

  3. The Relationships between Individualism, Nationalism, Ethnocentrism, and Authoritarianism in Flanders: A Continuous Time-Structural Equation Modeling Approach.

    Science.gov (United States)

    Angraini, Yenni; Toharudin, Toni; Folmer, Henk; Oud, Johan H L

    2014-01-01

    This article analyzes the relationships among nationalism (N), individualism (I), ethnocentrism (E), and authoritarianism (A) in continuous time (CT), estimated as a structural equation model. The analysis is based on the General Election Study for Flanders, Belgium, for 1991, 1995, and 1999. We find reciprocal effects between A and E and between E and I as well as a unidirectional effect from A on I. We furthermore find relatively small, but significant, effects from both I and E on N but no effect from A on N or from N on any of the other variables. Because of its central role in the N-I-E-A complex, mitigation of authoritarianism has the largest potential to reduce the spread of nationalism, ethnocentrism, and racism in Flanders.

  4. IS THERE A RELATIONSHIP BETWEEN FINANCIAL LITERACY, CAPITAL STRUCTURE AND COMPETITIVENESS OF SMEs?

    Directory of Open Access Journals (Sweden)

    Anamarija Delić

    2016-06-01

    Full Text Available The importance of financial market development for the economic development and competitiveness of a country is reflected in channelling of capital towards those investments that have the highest returns, thus ensuring liquidity and efficient grouping of enterprises, that is, risk-taking. Efficient risk-taking is primarily reflected in the availability of a large number of sources of funding, which allow enterprises freedom when forming their capital structure. Enterprises that do not have a large number of sources of funding at their disposal have to resort to debt financing when forming their capital structure, which ultimately means excessive financial vulnerability. Financial vulnerability, especially in times of the financial crisis, when fluctuations in the cost of capital are very high, reduces investment, growth and employment in the long-term. Small and medium-sized enterprises in the Croatian underdeveloped financial market must resort to borrowing, as the most readily available source of funding. Analysing the process of decision-making about capital structure on a sample of 108 small and medium-sized enterprises, it was observed that enterprises whose capital structure is less dependent on debt achieve better financial results and growth. The process of making financial decisions in those companies is in the hands of owners and/or managers and consultants with knowledge about the advantages and disadvantages of individual sources of funding. Financial knowledge is one of the most important determinants of the capital structure that will enable the growth and development of the small and medium-sized enterprise sector, as well as greater competitiveness of enterprises, regardless of size, activity, industry and the form of ownership of these enterprises. T-test and Levene’s test of equality of variances were used to investigate the relationship between the profitability of enterprises and their financial literacy.

  5. Relationship between Molecular Structure Characteristics of Feed Proteins and Protein Digestibility and Solubility

    Directory of Open Access Journals (Sweden)

    Mingmei Bai

    2016-08-01

    Full Text Available The nutritional value of feed proteins and their utilization by livestock are related not only to the chemical composition but also to the structure of feed proteins, but few studies thus far have investigated the relationship between the structure of feed proteins and their solubility as well as digestibility in monogastric animals. To address this question we analyzed soybean meal, fish meal, corn distiller’s dried grains with solubles, corn gluten meal, and feather meal by Fourier transform infrared (FTIR spectroscopy to determine the protein molecular spectral band characteristics for amides I and II as well as α-helices and β-sheets and their ratios. Protein solubility and in vitro digestibility were measured with the Kjeldahl method using 0.2% KOH solution and the pepsin-pancreatin two-step enzymatic method, respectively. We found that all measured spectral band intensities (height and area of feed proteins were correlated with their the in vitro digestibility and solubility (p≤0.003; moreover, the relatively quantitative amounts of α-helices, random coils, and α-helix to β-sheet ratio in protein secondary structures were positively correlated with protein in vitro digestibility and solubility (p≤0.004. On the other hand, the percentage of β-sheet structures was negatively correlated with protein in vitro digestibility (p<0.001 and solubility (p = 0.002. These results demonstrate that the molecular structure characteristics of feed proteins are closely related to their in vitro digestibility at 28 h and solubility. Furthermore, the α-helix-to-β-sheet ratio can be used to predict the nutritional value of feed proteins.

  6. Molecular characterization of the receptor binding structure-activity relationships of influenza B virus hemagglutinin.

    Science.gov (United States)

    Carbone, V; Kim, H; Huang, J X; Baker, M A; Ong, C; Cooper, M A; Li, J; Rockman, S; Velkov, T

    2013-01-01

    Selectivity of α2,6-linked human-like receptors by B hemagglutinin (HA) is yet to be fully understood. This study integrates binding data with structure-recognition models to examine the impact of regional-specific sequence variations within the receptor-binding pocket on selectivity and structure activity relationships (SAR). The receptor-binding selectivity of influenza B HAs corresponding to either B/Victoria/2/1987 or the B/Yamagata/16/88 lineages was examined using surface plasmon resonance, solid-phase ELISA and gel-capture assays. Our SAR data showed that the presence of asialyl sugar units is the main determinant of receptor preference of α2,6 versus α2,3 receptor binding. Changes to the type of sialyl-glycan linkage present on receptors exhibit only a minor effect upon binding affinity. Homology-based structural models revealed that structural properties within the HA pocket, such as a glyco-conjugate at Asn194 on the 190-helix, sterically interfere with binding to avian receptor analogs by blocking the exit path of the asialyl sugars. Similarly, naturally occurring substitutions in the C-terminal region of the 190-helix and near the N-terminal end of the 140-loop narrows the horizontal borders of the binding pocket, which restricts access of the avian receptor analog LSTa. This study helps bridge the gap between ligand structure and receptor recognition for influenza B HA; and provides a consensus SAR model for the binding of human and avian receptor analogs to influenza B HA.

  7. Structure-Activity Relationships of the Human Immunodeficiency Virus Type 1 Maturation Inhibitor PF-46396.

    Science.gov (United States)

    Murgatroyd, Christopher; Pirrie, Lisa; Tran, Fanny; Smith, Terry K; Westwood, Nicholas J; Adamson, Catherine S

    2016-09-15

    HIV-1 maturation inhibitors are a novel class of antiretroviral compounds that consist of two structurally distinct chemical classes: betulinic acid derivatives and the pyridone-based compound PF-46396. It is currently believed that both classes act by similar modes of action to generate aberrant noninfectious particles via inhibition of CA-SP1 cleavage during Gag proteolytic processing. In this study, we utilized a series of novel analogues with decreasing similarity to PF-46396 to determine the chemical groups within PF-46396 that contribute to antiviral activity, Gag binding, and the relationship between these essential properties. A spectrum of antiviral activity (active, intermediate, and inactive) was observed across the analogue series with respect to CA-SP1 cleavage and HIV-1 (NL4-3) replication kinetics in Jurkat T cells. We demonstrate that selected inactive analogues are incorporated into wild-type (WT) immature particles and that one inactive analogue is capable of interfering with PF-46396 inhibition of CA-SP1 cleavage. Mutations that confer PF-46396 resistance can impose a defective phenotype on HIV-1 that can be rescued in a compound-dependent manner. Some inactive analogues retained the capacity to rescue PF-46396-dependent mutants (SP1-A3V, SP1-A3T, and CA-P157S), implying that they can also interact with mutant Gag. The structure-activity relationships observed in this study demonstrate that (i) the tert-butyl group is essential for antiviral activity but is not an absolute requirement for Gag binding, (ii) the trifluoromethyl group is optimal but not essential for antiviral activity, and (iii) the 2-aminoindan group is important for antiviral activity and Gag binding but is not essential, as its replacement is tolerated. Combinations of antiretroviral drugs successfully treat HIV/AIDS patients; however, drug resistance problems make the development of new mechanistic drug classes an ongoing priority. HIV-1 maturation inhibitors are novel as they

  8. The relationship between context, structure, and processes with outcomes of 6 regional diabetes networks in Europe.

    Science.gov (United States)

    Mahdavi, Mahdi; Vissers, Jan; Elkhuizen, Sylvia; van Dijk, Mattees; Vanhala, Antero; Karampli, Eleftheria; Faubel, Raquel; Forte, Paul; Coroian, Elena; van de Klundert, Joris

    2018-01-01

    While health service provisioning for the chronic condition Type 2 Diabetes (T2D) often involves a network of organisations and professionals, most evidence on the relationships between the structures and processes of service provisioning and the outcomes considers single organisations or solo practitioners. Extending Donabedian's Structure-Process-Outcome (SPO) model, we investigate how differences in quality of life, effective coverage of diabetes, and service satisfaction are associated with differences in the structures, processes, and context of T2D services in six regions in Finland, Germany, Greece, Netherlands, Spain, and UK. Data collection consisted of: a) systematic modelling of provider network's structures and processes, and b) a cross-sectional survey of patient reported outcomes and other information. The survey resulted in data from 1459 T2D patients, during 2011-2012. Stepwise linear regression models were used to identify how independent cumulative proportion of variance in quality of life and service satisfaction are related to differences in context, structure and process. The selected context, structure and process variables are based on Donabedian's SPO model, a service quality research instrument (SERVQUAL), and previous organization and professional level evidence. Additional analysis deepens the possible bidirectional relation between outcomes and processes. The regression models explain 44% of variance in service satisfaction, mostly by structure and process variables (such as human resource use and the SERVQUAL dimensions). The models explained 23% of variance in quality of life between the networks, much of which is related to contextual variables. Our results suggest that effectiveness of A1c control is negatively correlated with process variables such as total hours of care provided per year and cost of services per year. While the selected structure and process variables explain much of the variance in service satisfaction, this is

  9. The Moderating Role of Corporate Governance on the Relationship between Capital Structure and Financial Performance: Evidence from Manufacturing Sector of Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Iqbal

    2017-02-01

    Full Text Available The key purpose of this research paper is to explore the moderating effect of Corporate Governance on the relationship between accounting base financial performance i.e. ROA, and ROE and Capital Structure of 173 Manufacturing firms listed in KSE of Pakistan for the period of 2009 to 2014. In this study multiple regression method is used under fixed effect regression model approach on panel data. The empirical results show that the inclusion of Corporate Governance Index (CGI as moderating variable has influenced the interaction between Capital Structure and Financial Performance which was positively significant. The result is generally found that the most of Pakistani manufacturing listed firms pursue good corporate governance mechanism and use good and optimal level of Capital Mix to get the better and high financial performance. Furthermore, the corporate governance sub-indices i.e. board structure (BOD-I and transparency & disclosure (DISC-III both also have positive and statistically significant association with both firms performance variables: ROA and ROE. Moreover, the ownership structure sub-index (OWS-II has not significant influence on financial performance. In last, the capital structure also has positive relationship with financial performance, interestingly about 70 per cent of Capital is financed by Equity capital and the Debt capital signifies 30 per cent only. The core significance of this paper is to investigate the impact of Corporate Governance practices on financial decisions from the Pakistani perspective.

  10. Composition - structure - properties relationships of peraluminous glasses for nuclear waste containment

    International Nuclear Information System (INIS)

    Piovesan, Victor

    2016-01-01

    Part of the Research and Development program concerning high level nuclear waste conditioning aims to assess new glass formulations able to incorporate a high waste content with enhanced properties in terms of homogeneity, thermal stability, long term behavior and process ability. This study focuses on peraluminous glasses, defined by an excess of aluminum ions Al"3"+ in comparison with modifier elements such as Na"+, Li"+ or Ca"2"+. A Design of Experiment approach has been employed to determine relationships between composition of simplified peraluminous glasses (SiO_2 - B_2O_3 - Al_2O_3 - Na_2O - Li_2O - CaO - La_2O_3) and their physical properties such as viscosity, glass transition temperature and glass homogeneity. Moreover, some structural investigation (NMR) was performed in order to better understand the structural role of Na"+, Li"+ and Ca"2"+ and the structural organization of peraluminous glasses. Then, physical and chemical properties of fully simulated peraluminous glasses were characterized to evaluate transposition between simplified and fully simulated glasses and also to put forward the potential of peraluminous glasses for nuclear waste containment. (author) [fr

  11. Red Wine Tannin Structure-Activity Relationships during Fermentation and Maceration.

    Science.gov (United States)

    Yacco, Ralph S; Watrelot, Aude A; Kennedy, James A

    2016-02-03

    The correlation between tannin structure and corresponding activity was investigated by measuring the thermodynamics of interaction between tannins isolated from commercial red wine fermentations and a polystyrene divinylbenzene HPLC column. Must and/or wine samples were collected throughout fermentation/maceration from five Napa Valley wineries. By varying winery, fruit source, maceration time, and cap management practice, it was considered that a reasonably large variation in commercially relevant tannin structure would result. Tannins were isolated from samples collected using low pressure chromatography and were then characterized by gel permeation chromatography and acid-catalyzed cleavage in the presence of excess phloroglucinol (phloroglucinolysis). Corresponding tannin activity was determined using HPLC by measuring the thermodynamics of interaction between isolated tannin and a polystyrene divinylbenzene HPLC column. This measurement approach was designed to determine the ability of tannins to hydrophobically interact with a hydrophobic surface. The results of this study indicate that tannin activity is primarily driven by molecular size. Compositionally, tannin activity was positively associated with seed tannins and negatively associated with skin and pigmented tannins. Although measured indirectly, the extent of tannin oxidation as determined by phloroglucinolysis conversion yield suggests that tannin oxidation at this stage of production reduces tannin activity. Based upon maceration time, this study indicates that observed increases in perceived astringency quality, if related to tannin chemistry, are driven by tannin molecular mass as opposed to pigmented tannin formation or oxidation. Overall, the results of this study give new insight into tannin structure-activity relationships which dominate during extraction.

  12. Quantitative structure-activity relationships for green algae growth inhibition by polymer particles.

    Science.gov (United States)

    Nolte, Tom M; Peijnenburg, Willie J G M; Hendriks, A Jan; van de Meent, Dik

    2017-07-01

    After use and disposal of chemical products, many types of polymer particles end up in the aquatic environment with potential toxic effects to primary producers like green algae. In this study, we have developed Quantitative Structure-Activity Relationships (QSARs) for a set of highly structural diverse polymers which are capable to estimate green algae growth inhibition (EC50). The model (N = 43, R 2  = 0.73, RMSE = 0.28) is a regression-based decision tree using one structural descriptor for each of three polymer classes separated based on charge. The QSAR is applicable to linear homo polymers as well as copolymers and does not require information on the size of the polymer particle or underlying core material. Highly branched polymers, non-nitrogen cationic polymers and polymeric surfactants are not included in the model and thus cannot be evaluated. The model works best for cationic and non-ionic polymers for which cellular adsorption, disruption of the cell wall and photosynthesis inhibition were the mechanisms of action. For anionic polymers, specific properties of the polymer and test characteristics need to be known for detailed assessment. The data and QSAR results for anionic polymers, when combined with molecular dynamics simulations indicated that nutrient depletion is likely the dominant mode of toxicity. Nutrient depletion in turn, is determined by the non-linear interplay between polymer charge density and backbone flexibility. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Relationships among the structural topology, bond strength, and mechanical properties of single-walled aluminosilicate nanotubes.

    Science.gov (United States)

    Liou, Kai-Hsin; Tsou, Nien-Ti; Kang, Dun-Yen

    2015-10-21

    Carbon nanotubes (CNTs) are regarded as small but strong due to their nanoscale microstructure and high mechanical strength (Young's modulus exceeds 1000 GPa). A longstanding question has been whether there exist other nanotube materials with mechanical properties as good as those of CNTs. In this study, we investigated the mechanical properties of single-walled aluminosilicate nanotubes (AlSiNTs) using a multiscale computational method and then conducted a comparison with single-walled carbon nanotubes (SWCNTs). By comparing the potential energy estimated from molecular and macroscopic material mechanics, we were able to model the chemical bonds as beam elements for the nanoscale continuum modeling. This method allowed for simulated mechanical tests (tensile, bending, and torsion) with minimum computational resources for deducing their Young's modulus and shear modulus. The proposed approach also enabled the creation of hypothetical nanotubes to elucidate the relative contributions of bond strength and nanotube structural topology to overall nanotube mechanical strength. Our results indicated that it is the structural topology rather than bond strength that dominates the mechanical properties of the nanotubes. Finally, we investigated the relationship between the structural topology and the mechanical properties by analyzing the von Mises stress distribution in the nanotubes. The proposed methodology proved effective in rationalizing differences in the mechanical properties of AlSiNTs and SWCNTs. Furthermore, this approach could be applied to the exploration of new high-strength nanotube materials.

  14. Optimizing the business and IT relationship--a structured approach to implementing a business relationship management framework.

    Science.gov (United States)

    Mohrmann, Gregg; Kraatz, Drew; Sessa, Bonnie

    2009-01-01

    The relationship between the business and the IT organization is an area where many healthcare providers experience challenges. IT is often perceived as a service provider rather than a partner in delivering quality patient care. Organizations are finding that building a stronger partnership between business and IT leads to increased understanding and appreciation of the technology, process changes and services that can enhance the delivery of care and maximize organizational success. This article will provide a detailed description of valuable techniques for optimizing the healthcare organization's business and IT relationship; considerations on how to implement those techniques; and a description of the key benefits an organization should realize. Using a case study of a healthcare provider that leveraged these techniques, the article will show how an organization can promote this paradigm shift and create a tighter integration between the business and IT.

  15. A study on the relationship between capital structure and the performance of production market: A case study of firms listed on Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Kobra Sadat Salek Esfahani

    2013-04-01

    Full Text Available One of the most complicated and challenging issues in today's financial managers is the relationship between the components of capital structure in terms of bonds and shares used for financing and share price of their company, and its effects on the macroeconomic variables. This research aims to study the relationship between the capital structure and performance of the production market in some firms listed on Tehran Stock Exchange (TSE. In this research, the index of capital structure is debt ratio and that of production market performance is sales growth and return of assets (ROA. The statistical sample of this research includes 128 companies, which have been active in 11 various industries and listed on TSE over the period 2005-2010. The statistical techniques used to test the hypotheses of this research include correlation coefficient and pooled least squares regression (panel data. Based on the results of our survey, there is a strong and significant relationship between debt ratio and return on assets among the companies listed on TSE and most industries especially based metals at the confidence level of 95%. In contrast, there is no strong and significant relationship between debt ratio and sales growth in the above-mentioned companies and in most industries.

  16. The relationship between species diversity and genetic structure in the rare Picea chihuahuana tree species community, Mexico.

    Science.gov (United States)

    Simental-Rodríguez, Sergio Leonel; Quiñones-Pérez, Carmen Zulema; Moya, Daniel; Hernández-Tecles, Enrique; López-Sánchez, Carlos Antonio; Wehenkel, Christian

    2014-01-01

    Species diversity and genetic diversity, the most basic elements of biodiversity, have long been treated as separate topics, although populations evolve within a community context. Recent studies on community genetics and ecology have suggested that genetic diversity is not completely independent of species diversity. The Mexican Picea chihuahuana Martínez is an endemic species listed as "Endangered" on the Red List. Forty populations of Chihuahua spruce have been identified. This species is often associated with tree species of eight genera in gallery forests. This rare Picea chihuahuana tree community covers an area no more than 300 ha and has been subject of several studies involving different topics such as ecology, genetic structure and climate change. The overall aim of these studies was to obtain a dataset for developing management tools to help decision makers implement preservation and conservation strategies. However, this unique forest tree community may also represent an excellent subject for helping us to understand the interplay between ecological and evolutionary processes in determining community structure and dynamics. The AFLP technique and species composition data were used together to test the hypothesis that species diversity is related to the adaptive genetic structure of some dominant tree species (Picea chihuahuana, Pinus strobiformis, Pseudotsuga menziesii and Populus tremuloides) of the Picea chihuahuana tree community at fourteen locations. The Hill numbers were used as a diversity measure. The results revealed a significant correlation between tree species diversity and genetic structure in Populus tremuloides. Because the relationship between the two levels of diversity was found to be positive for the putative adaptive AFLP detected, genetic and species structures of the tree community were possibly simultaneously adapted to a combination of ecological or environmental factors. The present findings indicate that interactions between

  17. Quantitative Structure Activity Relationship of Cinnamaldehyde Compounds against Wood-Decaying Fungi

    Directory of Open Access Journals (Sweden)

    Dongmei Yang

    2016-11-01

    Full Text Available Cinnamaldehyde, of the genius Cinnamomum, is a major constituent of the bark of the cinnamon tree and possesses broad-spectrum antimicrobial activity. In this study, we used best multiple linear regression (BMLR to develop quantitative structure activity relationship (QSAR models for cinnamaldehyde derivatives against wood-decaying fungi Trametes versicolor and Gloeophyllun trabeum. Based on the two optimal QSAR models, we then designed and synthesized two novel cinnamaldehyde compounds. The QSAR models exhibited good correlation coefficients: R2Tv = 0.910 for Trametes versicolor and R2Gt = 0.926 for Gloeophyllun trabeum. Small errors between the experimental and calculated values of two designed compounds indicated that these two QSAR models have strong predictability and stability.

  18. Using the Karolinska Scales of Personality on male juvenile delinquents: relationships between scales and factor structure.

    Science.gov (United States)

    Dåderman, Anna M; Hellström, Ake; Wennberg, Peter; Törestad, Bertil

    2005-01-01

    The aim of the present study was to investigate relationships between scales from the Karolinska Scales of Personality (KSP) and the factor structure of the KSP in a sample of male juvenile delinquents. The KSP was administered to a group of male juvenile delinquents (n=55, mean age 17 years; standard deviation=1.2) from four Swedish national correctional institutions for serious offenders. As expected, the KSP showed appropriate correlations between the scales. Factor analysis (maximum likelihood) arrived at a four-factor solution in this sample, which is in line with previous research performed in a non-clinical sample of Swedish males. More research is needed in a somewhat larger sample of juvenile delinquents in order to confirm the present results regarding the factor solution.

  19. Relationships among msx gene structure and function in zebrafish and other vertebrates.

    Science.gov (United States)

    Ekker, M; Akimenko, M A; Allende, M L; Smith, R; Drouin, G; Langille, R M; Weinberg, E S; Westerfield, M

    1997-10-01

    The zebrafish genome contains at least five msx homeobox genes, msxA, msxB, msxC, msxD, and the newly isolated msxE. Although these genes share structural features common to all Msx genes, phylogenetic analyses of protein sequences indicate that the msx genes from zebrafish are not orthologous to the Msx1 and Msx2 genes of mammals, birds, and amphibians. The zebrafish msxB and msxC are more closely related to each other and to the mouse Msx3. Similarly, although the combinatorial expression of the zebrafish msx genes in the embryonic dorsal neuroectoderm, visceral arches, fins, and sensory organs suggests functional similarities with the Msx genes of other vertebrates, differences in the expression patterns preclude precise assignment of orthological relationships. Distinct duplication events may have given rise to the msx genes of modern fish and other vertebrate lineages whereas many aspects of msx gene functions during embryonic development have been preserved.

  20. Political Market Orientation: A Framework for Understanding Relationship Structures in Political Parties

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Savigny, Heather

    2012-01-01

    This article is motivated by the growing need to integrate the current political science and marketing literature in order to provide a deeper understanding of the behaviour of political actors and their relationships with relevant stakeholder groups. In our article, we demonstrate how Ormrod...... strive for contextual sensitivity. By adopting this approach it is hoped that the fears noted by political scientists that political marketing is solely concerned with applying standard management models to political parties with the resulting emphasis on communication tactics at election time, together......’s conceptual model of political market orientation complements political science models of party organization by drawing attention to the competing interests of stakeholders in shaping party strategy and organizational structure. We treat parties as a multitude of actors rather than as monolithic entities...