5,716 research outputs found

    Evidence of a Critical Histidine Residue in Soluble Aspartic Aminotransferase

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    Photooxidation of extramitochondrial α-aspartate aminotransferase in the presence of methylene blue or Rose bengal leads to a loss of enzymatic activity which follows first order kinetics. Amino acid analysis shows that histidine is the only amino acid residue significantly affected by photooxidation. Of the 8 histidine residues present in the enzyme monomer, 2 are oxidized rapidly at a rate identical with that of the activity loss, while the other 6 are destroyed much more slowly. The pH dependence of the rate of the photo-induced inactivation of the enzyme corresponds to that expected for the photooxidation of imidazole groups. The behavior of the enzyme in Sephadex G-200 is identical before and after extensive photooxidation, while the starch gel electrophoretic pattern changes after photooxidation. It is concluded that the loss of enzyme activity caused by photooxidation is related to the destruction of 1 histidine residue

    Innovation Camps Methodology Handbook: Realising the potential of the Entrepreneurial Discovery Process for Territorial Innovation and Development.

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    The present Methodology Handbook is conceived to encourage regions and cities from all over Europe to adopt the Innovation Camps methodology as a tool to address collectively and effectively societal and economic challenges concerning local societies in a European context - notably in the field of Research and Innovation Smart Specialisation Strategies (RIS3) through an open, collaborative and inclusive Entrepreneurial Discover Process (EDP) between Quadruple Helix actors (i.e. government, industry, academia, and civil society).JRC.B.3-Territorial Developmen

    Dust Formation in the Wind of AGB Stars—The Effects of Mass, Metallicity and Gas-Dust Drift

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    Dust production in the wind of stars evolving through the asymptotic giant branch is investigated by using a stationary wind model, applied to results from stellar evolution modelling. Results regarding 1–8M⊙ stars of metallicities Z=0.014 (solar) and Z=2×10−3 are compared, to infer the role played by stellar mass and chemical composition on the dust formation process. We find a dichotomy in mass: stars of (initial) mass below ∼3M⊙ produce silicates and alumina dust before they become carbon stars, then carbonaceous dust; the higher mass counterparts produce only silicates and alumina dust, in quantities that scale with metallicity. The presence of drifts with average drift velocities ∼5 Km/s leads to higher dust formation rates owing to the higher growth rates of the dust grains of the different species. However, no significant changes are found in the overall optical depths, because the higher rate of dust formations favours a fast expansion of the wind, that prevents further significant production of dust. As far as oxygen-rich stars are concerned, the presence of drifts makes the main dust component to change from olivine to pyroxene. The release of the assumption that the number density of the seed particles is independent of the dust species considered affects dust formation in the wind of carbon stars: a factor 10 reduction in the density of the seeds of SiC leads to bigger sized SiC grains, and partly inhibits the formation of solid carbon, since the wind is accelerated and the densities in the carbon formation zone are smaller. No substantial differences are found in the winds of oxygen-rich stars

    Sex Difference in Cardiorespiratory Stress from High-Intensity Interval Exercise

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    High-intensity interval exercise is time efficient and has similar cardiorespiratory health benefits as moderate-intensity continuous exercise. However, the prescription of high-intensity exercise may differ between men and women due to sex differences in cardiovascular function. PURPOSE: Therefore, the objective of this study was to examine whether sex differences exist for absolute and relative oxygen uptake (VO2) and heart rate (HR) when exercise was performed at a percentage of maximal cycling work rate measured in watts (Wmax). METHODS: We recruited 8 active college-aged participants (5 men, 3 women). Participants completed an incremental maximal exercise test on a cycle ergometer while VO2, HR, and Wmax were recorded. On a separate day, participants completed a high intensity interval session (4 min bouts with 3 min active recovery) prescribed at 65%Wmax for each bout and at 15%Wmax for the recovery. VO2, HR, and W were averaged from the last minute of each exercise bout for analysis using an independent t-test for sex comparisons. Data are reported in means ± standard deviations and significance was set at PRESULTS: Men exercised at a greater absolute workload than women during interval exercise (191±14 vs. 95±15 W; P2 was higher in men than women during exercise (2.7±0.4 vs. 1.5±0.3 L/min; PP=0.23). Relative VO2 (67±11 vs. 74±6 %VO2max; P=0.15) and HR (95±3 vs. 93±3 %HRmax; P=0.30) were also similar during exercise between sexes. CONCLUSION: In summary, these preliminary data suggest prescribing high-intensity interval exercise at a percentage of maximal work rate results in similar relative cardiorespiratory stress between men and women

    Paratuberculosis at European scale: an overview from 2010 to 2017

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    Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of paratuberculosis (PTB), a disease affecting domestic and wild ruminants. MAP may also play a zoonotic role in Crohn's disease. Although both governments and industries are carrying out programmes to prevent and control the infection, there is a lack of harmonization across Europe. Moreover, the success of these programmes is influenced by the current lack of sensitivity of the diagnostic tests used. For these reasons, it is complex to evaluate the overall epidemiological situation of this disease. This study describes the European distribution of PTB from 2010 to 2017 using the information reported by Member Countries to the OIE. Countries were classified in three categories ('Absent', 'Epizootic', 'Enzootic') depending on the disease epidemiology, and the trend of countries reporting the disease presence was computed throughout the study period. A multilevel model with random slope was built for twelve countries, with complete reporting history. Most of the countries (57.44%) were classified as 'Enzootic'. The percentage of countries reporting the disease presence slightly increased along the study period, probably due to the improvement of PTB monitoring, rather than to a deterioration of the epidemiological situation of the disease in Europe. Results of the model account for different dynamics in the number of outbreaks reported by 'Enzootic' and 'Epizootic' countries

    VISUALIZATION MODEL FOR PRODUCT LIFECYCLE MANAGEMENT

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    Product Lifecycle Management (PLM) demonstrated to be a good strategy for manufacturing enterprises. In spite of all the benefits it is not still clear how to implement it in industry. This article presents a visualization model of enterprise processes for a PLM system. It presents in a graphic way the main elements of a product lifecycle. The model identifies what is done (process, activities), when it is done (workflows), who does what (roles - skills) and how it can be done better (methods and tools). UML-RUP is used as representation technique. A case study, which analyzes the specification and inspection procedures of geometric tolerances according to the GPS approach, proves the convenience of this model for supporting PLM implementation

    Boundary conditions for the quantum Hall effect

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    We formulate a self-consistent model of the integer quantum Hall effect on an infinite strip, using boundary conditions to investigate the influence of finite-size effects on the Hall conductivity. By exploiting the translation symmetry along the strip, we determine both the general spectral properties of the system for a large class of boundary conditions respecting such symmetry, and the full spectrum for (fibered) Robin boundary conditions. In particular, we find that the latter introduce a new kind of states with no classical analogues, and add a finer structure to the quantization pattern of the Hall conductivity. Moreover, our model also predicts the breakdown of the quantum Hall effect at high values of the applied electric field.Comment: 41 pages, 12 figure
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