1,518 research outputs found
The carbon footprint appraisal of local visitor travel in Brazil: A case of the Rio de Janeiro-São Paulo itinerary
Tourism transportation contributes substantially to the global carbon footprint. This contribution is predicted to enlarge, especially in ‘emerging’ tourism markets, and hence urgent carbon mitigation is necessary. Effective mitigation is determined by reliable carbon footprint assessments whose number is however limited, particularly for developing countries with growing tourism. This study applied the life cycle assessment (LCA) based method to appraise the carbon significance of various transport modes between Rio de Janeiro and São Paulo, the key itinerary for travel with leisure and tourism purposes by local residents and overseas visitors in Brazil. Given the envisaged rise in biofuel use in the Brazilian transportation sector, this study is unique in that it evaluated the carbon reduction potential offered by biofuel. The study demonstrated that overland public transport represents the most carbon-efficient mode of local transportation. It further highlighted the crucial role of biofuel in minimising the carbon intensity of transportation between Rio de Janeiro and São Paulo. Policy-making and managerial recommendations were put forward to facilitate more climate-benign local transportation practices
Applying the facility location problem model for selection of more climate benign mega sporting event hosts: A case of the FIFA World Cups.
Sporting mega-events generate substantial carbon footprint where return transportation of event participants and visitors between the source and host countries makes the largest contribution. To enhance environmental sustainability of sporting mega-events, it is paramount to select a host country with the lowest carbon footprint from international transportation without compromising the magnitude of major visitor flows. The Facility Location Problem (FLP) model represents an established tool employed in the business environment to determine the best location for the installation of facilities to provide for existing or envisaged consumer demand. The model has proven its feasibility in a number of economic sectors, but rarely been applied in tourism, and never with sustainability management and planning purposes. This study contributes to knowledge by demonstrating the applicability of the FLP model when planning for sporting mega-events. The model enables selection of a host country with better climate credentials by quantifying the magnitude of international transportation of the event participants alongside the associated carbon footprint. Application of the FLP model to the FIFA World Cups shows that, to facilitate the progress of these mega-events towards sustainability, a decision on a host country should be made after the team qualification round, rather than before, as it currently stands. The model can then identify prospective hosts with the lowest carbon footprint from international transportation
Optical von Neumann measurement
We present an optical scheme that realizes the standard von Neumann
measurement model, providing an indirect measurement of a quadrature of the
field with controllable Gaussian state-reduction. The scheme is made of simple
optical elements, as laser sources, beam splitters, and phase sensitive
amplifiers, along with a feedback mechanism that uses a Pockels cell. We show
that the von Neumann measurement is achieved without the need of working in a
ultra-short pulsed regime.Comment: One latex figure. Accepted on Phys. Lett.
Mobility management architecture in different RATs based network slicing
© 2018 IEEE. Network slicing is an architectural solution that enables the future 5G network to offer a high data traffic capacity and efficient network connectivity. Moreover, software defined network (SDN) and network functions virtualization (NFV) empower this architecture to visualize the physical network resources. The network slicing identified as a multiple logical network, where each network slice dedicates as an end-to-end network and works independently with other slices on a common physical network resources. Most user devices have more than one smart wireless interfaces to connect to different radio access technologies (RATs) such as WiFi and LTE, thereby network operators utilize this facility to offload mobile data traffic. Therefore, it is important to enable a network slicing to manage different RATs on the same logical network as a way to mitigate the spectrum scarcity problem and enables a slice to control its users mobility across different access networks. In this paper, we propose a mobility management architecture based network slicing where each slice manages its users across heterogeneous radio access technologies such as WiFi, LTE and 5G networks. In this architecture, each slice has a different mobility demands and these demands are governed by a network slice configuration and service characteristics. Therefore, our mobility management architecture follows a modular approach where each slice has individual module to handle the mobility demands and enforce the slice policy for mobility management. The advantages of applying our proposed architecture include: i) Sharing network resources between different network slices; ii) creating logical platform to unify different RATs resources and allowing all slices to share them; iii) satisfying slice mobility demands
Temperature-dependent relaxation times in a trapped Bose-condensed gas
Explicit expressions for all the transport coefficients have recently been
found for a trapped Bose condensed gas at finite temperatures. These transport
coefficients are used to define the characteristic relaxation times, which
determine the crossover between the mean-field collisionless and the two-fluid
hydrodynamic regime. These relaxation times are evaluated as a function of the
position in the trap potential. We show that all the relaxation times are
dominated by the collisions between the condensate and the non-condensate
atoms, and are much smaller than the standard classical collision time used in
most of the current literature. The 1998 MIT study of the collective modes at
finite temperature is shown to have been well within the two-fluid hydrodynamic
regime.Comment: 4 pages, 3 figures, to be published in Phys. Rev.
Oscillating Solitons Pinned to a Nonmagnetic Impurity in Layered Antiferromagnets
We argue that an oscillatory motion of impurity-pinned solitons may occur in
layered antiferromagnetic compounds. The characteristic frequencies of these
modes, that may be detected by resonance or inelastic neutron scattering, are
estimated analytically and depend on the soliton sizes and types .Comment: 11 pages, 1 figur
Vortex behavior near a spin vacancy in 2D XY-magnets
The dynamical behavior of anisotropic two dimensional Heisenberg models is
still a matter of controversy. The existence of a central peak at all
temperatures and a rich structure of magnon peaks are not yet understood. It
seems that the central peaks are related, in some way, to structures like
vortices. In order to contribute to the discussion of the dynamical behavior of
the model we use Monte Carlo and spin dynamics simulations as well analytical
calculations to study the behavior of vortices in the presence of nonmagnetic
impurities. Our simulations show that vortices are attracted and trapped by the
impurities. Using this result we show that if we suppose that vortices are not
very much disturbed by the presence of the impurities, then they work as an
attractive potential to the vortices explaining the observed behavior in our
simulations.Comment: 4 pages, 6 figure
Effect of Chromatographic Conditions on Supercoiled Plasmid DNA Stability and Bioactivity
Funding: This work was supported by FEDER funds through the POCI—COMPETE 2020 Operational Programme Competitiveness and Internationalization in Axis I—Strengthening research, technological development, and innovation (Project POCI-01-0145-FEDER-007491), and National Funds by FCT Foundation for Science and Technology (Project UID/Multi /00709/2013). This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES. G.M. Azevedo acknowledges the support and fellowship of Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq/203482/2014-0). J.F.A. Valente acknowledges the PhD fellowship (Ref SFRH/BD/96809/2013) from FCT.Acknowledgments: The authors would like to thank Thomas Roberts for providing the pcDNA3–FLAG–p53
construct through Addgene, ref: 10838.The dysfunction of the tumor suppressor gene TP53 has been associated with the pathogenesis of the majority of the cases of cancer reported to date, leading the cell to acquire different features known as the cancer hallmarks. In normal situations, the protein p53 protects the cells against tumorigenesis. By detecting metabolic stress or DNA damage in response to stress, p53 can lead the cell to senescence, autophagy, cell cycle arrest, DNA repair, and apoptosis. Thus, in the case of p53 mutations, it is reasonable to assume that the reestablishment of its function, may restrain the proliferation of cancer cells. The concept of cancer gene therapy can be based on this assumption, and suitable biotechnological approaches must be explored to assure the preparation of gene-based biopharmaceuticals. Although numerous procedures have already been established to purify supercoiled plasmid DNA (sc pDNA), the therapeutic application is highly dependent on the biopharmaceutical’s activity, which can be affected by the chromatographic conditions used. Thus, the present work aims at comparing quality and in vitro activity of the supercoiled (sc) isoform of the p53 encoding plasmid purified by three different amino acids-based chromatographic strategies, involving histidine–agarose, arginine–macroporous, and histidine–monolith supports. The B-DNA topology was maintained in all purified pDNA samples, but their bioactivity, related to the induction of protein p53 expression and apoptosis in cancer cells, was higher with arginine–macroporous support, followed by histidine–monolith and histidine–agarose. Despite the purity degree of 92% and recovery yield of 43% obtained with arginine–macroporous, the sc pDNA sample led to a higher expression level of the therapeutic p53 protein (58%) and, consequently, induced a slightly higher apoptotic effect (27%) compared with sc pDNA samples obtained with histidine–monolithic support (26%) and histidine–agarose support (24%). This behavior can be related to the mild chromatographic conditions used with arginine–macroporous support, which includes the use of low salt concentrations, at neutral pH and lower temperatures, when compared to the high ionic strength of ammonium sulfate and acidic pH used with histidine-based supports. These results can contribute to field of biopharmaceutical preparation, emphasizing the need to control several experimental conditions while adapting and selecting the methodologies that enable the use of milder conditions as this can have a significant impact on pDNA stability and biological activity.info:eu-repo/semantics/publishedVersio
Effect of air pollution on diabetes and cardiovascular diseases in São Paulo, Brazil
Type 2 diabetes increases the risk of cardiovascular mortality and these patients, even without previous myocardial infarction, run the risk of fatal coronary heart disease similar to non-diabetic patients surviving myocardial infarction. There is evidence showing that particulate matter air pollution is associated with increases in cardiopulmonary morbidity and mortality. The present study was carried out to evaluate the effect of diabetes mellitus on the association of air pollution with cardiovascular emergency room visits in a tertiary referral hospital in the city of São Paulo. Using a time-series approach, and adopting generalized linear Poisson regression models, we assessed the effect of daily variations in PM10, CO, NO2, SO2, and O3 on the daily number of emergency room visits for cardiovascular diseases in diabetic and non-diabetic patients from 2001 to 2003. A semi-parametric smoother (natural spline) was adopted to control long-term trends, linear term seasonal usage and weather variables. In this period, 45,000 cardiovascular emergency room visits were registered. The observed increase in interquartile range within the 2-day moving average of 8.0 µg/m³ SO2 was associated with 7.0% (95%CI: 4.0-11.0) and 20.0% (95%CI: 5.0-44.0) increases in cardiovascular disease emergency room visits by non-diabetic and diabetic groups, respectively. These data indicate that air pollution causes an increase of cardiovascular emergency room visits, and that diabetic patients are extremely susceptible to the adverse effects of air pollution on their health conditions.Disciplina de ClÃnica Médica, Departamento de MedicinaUniversidade de São Paulo - Laboratório de Poluição Atmosférica Experimental, Faculdade de Medicina, USP (FM-USP
Optimized quantum nondemolition measurement of a field quadrature
We suggest an interferometric scheme assisted by squeezing and linear
feedback to realize the whole class of field-quadrature quantum nondemolition
measurements, from Von Neumann projective measurement to fully non-destructive
non-informative one. In our setup, the signal under investigation is mixed with
a squeezed probe in an interferometer and, at the output, one of the two modes
is revealed through homodyne detection. The second beam is then
amplitude-modulated according to the outcome of the measurement, and finally
squeezed according to the transmittivity of the interferometer. Using strongly
squeezed or anti-squeezed probes respectively, one achieves either a projective
measurement, i.e. homodyne statistics arbitrarily close to the intrinsic
quadrature distribution of the signal, and conditional outputs approaching the
corresponding eigenstates, or fully non-destructive one, characterized by an
almost uniform homodyne statistics, and by an output state arbitrarily close to
the input signal. By varying the squeezing between these two extremes, or
simply by tuning the internal phase-shift of the interferometer, the whole set
of intermediate cases can also be obtained. In particular, an optimal quantum
nondemolition measurement of quadrature can be achieved, which minimizes the
information gain versus state disturbance trade-off
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