930 resultados para Biocatalysis at Moderate Pressures


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This study examines how product attribute typicality and brand commitment influence the effects of comparative versus non-comparative ads on brand attitudes. Employing perspectives from the literatures on typicality and commitment, the study examines the effects of commitment to the comparison brand on the effectiveness of comparative versus non-comparative advertising. A between-informants experiment uses data from 466 student informants. It is hypothesized that (a) when the attribute under consideration is typical (atypical), among comparison brand committed informants, a non-comparative ad is more (no more) persuasive than a comparative ad, (b) when the attribute under consideration is typical, among comparison brand non-committed informants, a comparative ad is more persuasive than a non-comparative ad, and (c) when the attribute under consideration is atypical, among comparison brand non-committed informants, a comparative ad is likely to be more persuasive than a non-comparative ad, but the effect will be weaker than in the case of a typical attribute. Hypothesis (a) is supported while (b) has directional support. The results support a three-way interaction between consumer commitment, attribute typicality, and type of advertisement. The findings are relevant to a variety of contexts, such as markets characterized by high levels of market share and commitment for the market leader as well as fragmented markets where market share and commitment levels are low.

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This study examines the relationships between children's impulsivity, their eating behaviours, and their perceptions of their parent's feeding practices. 153 10-13. year old children completed questionnaires assessing their eating behaviours, their impulsiveness and their perception of their parent's feeding practices. Children's reports of dysfunctional eating behaviours were significantly correlated with their perceptions of their parents feeding practices and with their levels of impulsivity. Children's reports of parental monitoring of their food intake significantly moderated the influence of child impulsiveness upon emotional eating. Children's perceptions of parental monitoring of their food intake may potentially have a protective effect at preventing more impulsive children from eating in response to emotional feelings. © 2011 Elsevier Ltd.

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Background: Proton Magnetic Resonance Spectroscopy (H-MRS) is a non-invasive imaging technique that enables quantification of neurochemistry in vivo and thereby facilitates investigation of the biochemical underpinnings of human cognitive variability. Studies in the field of cognitive spectroscopy have commonly focused on relationships between measures of N-acetyl aspartate (NAA), a surrogate marker of neuronal health and function, and broad measures of cognitive performance, such as IQ. Methodology/Principal Findings: In this study, we used H-MRS to interrogate single-voxels in occipitoparietal and frontal cortex, in parallel with assessments of psychometric intelligence, in a sample of 40 healthy adult participants. We found correlations between NAA and IQ that were within the range reported in previous studies. However, the magnitude of these effects was significantly modulated by the stringency of data screening and the extent to which outlying values contributed to statistical analyses. Conclusions/Significance: H-MRS offers a sensitive tool for assessing neurochemistry non-invasively, yet the relationships between brain metabolites and broad aspects of human behavior such as IQ are subtle. We highlight the need to develop an increasingly rigorous analytical and interpretive framework for collecting and reporting data obtained from cognitive spectroscopy studies of this kind. © 2014 Patel, Blyth, Griffiths, Kelly and Talcott.

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OBJECTIVE. Our objective with this study was to examine whether observed maternal control during feeding at 6 months of age moderates the development of early infant weight gain during the first year of life. METHODS. Sixty-nine women were observed feeding their 6-month-old infants during a standard meal. Mealtimes were coded for maternal use of controlling feeding behavior. All infants were weighed at birth and at 6 and 12 months of age, and weight gain was calculated from birth to 6 months and from 6 to 12 months. Weight scores and weight gain scores were standardized for prematurity, age, and gender. RESULTS. Infant weight gain between 6 and 12 months of age was predicted by an interaction between early infant weight gain (birth to 6 months) and observed maternal control during feeding at 6 months. When maternal control was moderate or low, there was a significant interaction with weight gain from birth to 6 months in the prediction of later infant weight gain from 6 to 12 months, such that infants who showed slow early weight gain accelerated in their subsequent weight gain, and those with greater early weight gain decelerated. Conversely, when maternal control was high, infant weight gain followed the opposite pattern. CONCLUSION. Maternal control of solid feeding can moderate infant weight gain.

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The structure and dynamics of methane in hydrated potassium montmorillonite clay have been studied under conditions encountered in sedimentary basin and compared to those of hydrated sodium montmorillonite clay using computer simulation techniques. The simulated systems contain two molecular layers of water and followed gradients of 150 barkm-1 and 30 Kkm-1 up to a maximum burial depth of 6 km. Methane particle is coordinated to about 19 oxygen atoms, with 6 of these coming from the clay surface oxygen. Potassium ions tend to move away from the center towards the clay surface, in contrast to the behavior observed with the hydrated sodium form. The clay surface affinity for methane was found to be higher in the hydrated K-form. Methane diffusion in the two-layer hydrated K-montmorillonite increases from 0.39×10-9 m2s-1 at 280 K to 3.27×10-9 m2s-1 at 460 K compared to 0.36×10-9 m2s-1 at 280 K to 4.26×10-9 m2s-1 at 460 K in Na-montmorillonite hydrate. The distributions of the potassium ions were found to vary in the hydrates when compared to those of sodium form. Water molecules were also found to be very mobile in the potassium clay hydrates compared to sodium clay hydrates. © 2004 Elsevier Inc. All All rights reserved.

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Computer simulation has been used to study the structure and dynamics of methane in hydrated sodium montmorillonite clays under conditions encountered in sedimentary basins. Systems containing approximately one, two, three and four molecular layers of water have followed gradients of 150 bar km-1 and 30Kkm-1, to a maximum burial depth of 6 km (900 bar and 460 K). Methane is coordinated to approximately 19 oxygen atoms, of which typically 6 are provided by the clay surface. Only in the three- and four-layer hydrates is methane able to leave the clay surface. Diffusion depends strongly on the porosity (water content) and burial depth: self-diffusion coefficients are in the range 0.12 × 10-9m2s-1 for water and 0.04 × 10−9m2s−1 < D < 8.64 × 10−9m2s−1 for methane. Bearing in mind that porosity decreases with burial depth, it is estimated that maximum diffusion occurs at around 3 km. This is in good agreement with the known location of methane reservoirs in sedimentary basins.

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Purpose: To investigate the relationship between retinal microvascular reactivity, circulatory markers for CVD risk and systemic antioxidative defence capacity in healthy middle-aged individuals with low to moderate risk of CVD. Methods: Retinal vascular reactivity to flickering light was assessed in 102 healthy participants (46-60 years) by means of dynamic retinal vessel analysis (DVA). Other vascular assessments included carotid intima-media thickness (C-IMT) and blood pressure (BP) measurements. Total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and blood glutathione levels in its reduced (GSH) and oxidized (GSSG) forms were also determined for each participant, along with Framingham risk scores (FRS). Results: Retinal arterial baseline diameter fluctuation (BDF) was independently, significantly and negatively influenced by LDL-C levels (β = -0.53, p = 0.027). Moreover, the arterial dilation slope (SlopeAD) was independently, significantly and positively associated with redox index (GSH: GSSG ratio, β = 0.28, p = 0.016), while the arterial constriction slope (SlopeAC) was significantly and negatively influenced by blood GSH levels (β = -0.20, p = 0.042), and positively associated with FRS (β = 0.25, p = 0.009). Venous BDF and dilation amplitude (DA) were also negatively influenced by plasma LDL-C levels (β = -0.83, p = 0.013; and β = -0.22, p = 0.028, respectively). Conclusions: In otherwise healthy individuals with low to moderate cardiovascular risk, retinal microvascular dilation and constriction responses to stress levels are influenced by systemic antioxidant capacity, and circulating markers for cardiovascular risk.

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The effect of liquid medium and its pressure on the photoluminescence of ZnO nanoparticles prepared via laser ablation of Zn targets in various water-ethanol mixtures is studied. As the ethanol content increases, the photoluminescence of the product changes, while metallic zinc is observed to emerge in nanomaterials prepared in ethanol-rich environments. The applied pressure had a less profound effect, mainly affecting materials produced in water or water-ethanol, and much less those generated in pressurized ethanol. Tuning the reactivity of the liquid and pressurizing it during laser ablation is demonstrated to be promising for tailoring the emission properties of the product.

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Technological advances have driven some attempt of vital parameters monitoring in adverse environments; these improvements will make possible to monitor cardiac activity also in automotive environments. In this scenario, heart rate changes associated with alcohol consumption, become of great importance to assess the drivers state during time. This paper presents the results of a first set of experiments aimed to discover heart rate variability modification induced by moderate assumption of alcoholic drink (i.e. single draft beer) as that typically occurs in weekend among some people. In the study, twenty subjects were enrolled and for each of them two electrocardiographic recordings were carried out: the first before alcohol ingestion and the second after 25-30 minutes. Each participant remained fasting until the second ECG acquisition was completed. ECG signal were analyzed by typical timedomain, frequency and non linear analysis. Results showed a small increase in LF/HF ratio which reflects a dominance of the sympathetic system over the parasympathetic system, and an increase in signal complexity as proven by non linear analysis. However, the study highlighted the need to monitor HRV starting from alcohol ingestion until its complete metabolization to allow a more precise description of its variation. © Springer International Publishing Switzerland 2014.

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2000 Mathematics Subject Classification: 62G07, 60F10.

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Up to January 2011 authoritarian political regimes in the Middle East had widely been considered stable due to the armed forces, the underdeveloped political institutions, the economic embeddedness of the regimes, the neo-patrimonial structure of the Arab societies and, eventually the characteristics of Islam. Middle Eastern political systems are often considered to belong to a special sub-group of non-democratic regimes called “liberalized autocracies”. The 2011 events show that there is a new, as yet non-defined political structure emerging. Although there are different interpretations of the developments, there is a consensus on the determinant role of the Islamist organizations in the development of the new political structure. The results of the Egyptian and Tunisian parliamentary elections show that the secular political parties could not attract the public, while in Tunisia the long forbidden Hizb an-Nahda could form a government. In Egypt Hizb al-Hurriya established by the Muslim Brotherhood in 2011 won almost half of the parliamentary mandates, and to a great surprise, the Salafi Hizb an-Nour also received 24.3% of the votes. On the basis of the above developments the thesis of the Islamist re-organization of the Middle East, i.e. of a new wave of Islamism was elaborated, according to which the main political winners of the revolts in the Arab countries are the Islamist organizations, which could step in and fill in the political vacuum. While some speak of an Islamist autumn or Islamist winter as the result of the Arab Spring, others prefer the term Islamic revolutions.

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To better understand high pressure behavior of solids, both silicates and oxides have been investigated to clarify the high pressure melting, phase transformations and thermal parameters as well as their size dependences, both theoretically and experimentally. ^ To judge the precision of data determined experimentally, the reliabilities of different high pressure techniques have been discussed. A thermodynamic model has been developed and demonstrated to be able to closely reproduce the melting of solids by comparison between results calculated and data obtained experimentally, including metals (Al, Ni and Pt), Silicates (Mg3Al 2Si3O12 and CaMgSi2O6), Halides (NaCl, CsCl and LiF) and Oxides (MgO, FeO and Al2O3). The melting data obtained have been discussed to address the dynamics of the Earth's interior. ^ Results obtained with Raman spectroscopy and x-ray diffraction show that solids including silicates (andradite and pyrope) and oxides (CeO2 and TiO2) undergo a series of pressure-induced phase transformations. The effects of particle size under high pressures have been investigated. The results obtained indicate that the reduction of particle size leads to the enhancement of the bulk modulus and a significant decrease of transition pressure in TiO2 (rutile) and CeO2. The pressure-induced amorphization in anatase also results from the size effects. ^ Combining the data obtained with global seismic tomography, the physics and chemistry of the Earth's mantle and the dynamics of the core-mantle interaction have been discussed. The high pressure phases of Al3+- and Fe3+-bearing minerals play important roles in the dynamics of the lower mantle. ^

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Republican John Sherman, United States Congressman, Senator, Treasury Secretary, and Secretary of State had a political career of major importance from 1855 to 1898, yet there have been only casual references by historians and only two biographies of him, with the most recent published in 1902. From a strong Whig Party background, he was first elected to the United States House of Representatives in 1854; switching to the Republicans that same year. Then elevated to the Senate in 1861, he served in that body throughout the Civil War and Reconstruction when he was the most important voice of party unity and moderation. In 1877, the new President Rutherford Hayes appointed Sherman Secretary of the Treasury. He returned to the Senate after the Hayes administration where he sat for the following 15 years. In this particularly notable period, he not only led the upper house, but he engineered more bills in Congress which bore his name than any other member of either house. These included the critically important Sherman Silver Purchase Act, the Sherman Anti-Trust Act and Sherman Inter-State Commerce Act. In 1897 he left the Senate finally when William McKinley appointed him Secretary of State. ^ Through this long, distinguished career, Sherman was involved in all the important legislation that brought the country through the Civil War and Reconstruction and into the post-war world of the Gilded Age of rapid industrialization, and urban growth, Politically, he never strayed far from the nationalistic and economic principles of the Whig Party, and brought both these values to bear in the Republican Party that dominated American political life from 1860 to 1900. Similarly, party loyalty and loyalty to the President always characterized his service. He was indeed, an exemplar of political and statesmanship. ^ While research for this dissertation included review of both journal and monographic literature, its basis lies more critically in primary research in unpublished archival material in repositories from Maine to Ohio, in particular the Library of Congress. ^

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Transition metals (Ti, Zr, Hf, Mo, W, V, Nb, Ta, Pd, Pt, Cu, Ag, and Au) are essential building units of many materials and have important industrial applications. Therefore, it is important to understand their thermal and physical behavior when they are subjected to extreme conditions of pressure and temperature. This dissertation presents: • An improved experimental technique to use lasers for the measurement of thermal conductivity of materials under conditions of very high pressure (P, up to 50 GPa) and temperature (T up to 2500 K). • An experimental study of the phase relationship and physical properties of selected transition metals, which revealed new and unexpected physical effects of thermal conductivity in Zr, and Hf under high P-T. • New phase diagrams created for Hf, Ti and Zr from experimental data. • P-T dependence of the lattice parameters in α-hafnium. Contrary to prior reports, the α-ω phase transition in hafnium has a negative dT/dP slope. • New data on thermodynamic and physical properties of several transition metals and their respective high P-T phase diagrams. • First complete thermodynamic database for solid phases of 13 common transition metals was created. This database has: All the thermochemical data on these elements in their standard state (mostly available and compiled); All the equations of state (EoS) formulated from pressure-volume-temperature data (measured as a part of this study and from literature); Complete thermodynamic data for selected elements from standard to extreme conditions. The thermodynamic database provided by this study can be used with available thermodynamic software to calculate all thermophysical properties and phase diagrams at high P-T conditions. For readers who do not have access to this software, tabulated values of all thermodynamic and volume data for the 13 metals at high P-T are included in the APPENDIX. In the APPENDIX, a description of several other high-pressure studies of selected oxide systems is also included. Thermophysical properties (Cp, H, S, G) of the high P-T ω-phase of Ti, Zr and Hf were determined during the optimization of the EoS parameters and are presented in this study for the first time. These results should have important implications in understanding hexagonal-close-packed to simple-hexagonal phase transitions in transition metals and other materials.

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This special issue on ‘Science for the management of subtropical embayments: examples from Shark Bay and Florida Bay’ is a valuable compilation of individual research outcomes from Florida Bay and Shark Bay from the past decade and addresses gaps in our scientific knowledge base in Shark Bay especially. Yet the compilation also demonstrates excellent research that is poorly integrated, and driven by interests and issues that do not necessarily lead to a more integrated stewardship of the marine natural values of either Shark Bay or Florida Bay. Here we describe the status of our current knowledge, introduce the valuable extension of the current knowledge through the papers in this issue and then suggest some future directions. For management, there is a need for a multidisciplinary international science program that focusses research on the ecological resilience of Shark Bay and Florida Bay, the effect of interactions between physical environmental drivers and biological control through behavioural and trophic interactions, and all under increased anthropogenic stressors. Shark Bay offers a ‘pristine template’ for this scale of study.