4,855 research outputs found
Direct determination of the solar neutrino fluxes from solar neutrino data
We determine the solar neutrino fluxes from a global analysis of the solar
and terrestrial neutrino data in the framework of three-neutrino mixing. Using
a Bayesian approach we reconstruct the posterior probability distribution
function for the eight normalization parameters of the solar neutrino fluxes
plus the relevant masses and mixing, with and without imposing the luminosity
constraint. This is done by means of a Markov Chain Monte Carlo employing the
Metropolis-Hastings algorithm. We also describe how these results can be
applied to test the predictions of the Standard Solar Models. Our results show
that, at present, both models with low and high metallicity can describe the
data with good statistical agreement.Comment: 24 pages, 1 table, 7 figures. Acknowledgments correcte
Smart and sustainable urban logistic applications aided by intelligent techniques
[EN] CO2-free urban logistics is one of the 10 objectives to reach by 2030 as part of transport policy. What technologies can help to accomplish it? In this paper, we discuss the very complex situation that today¿s big and modern cities are facing with a tremendous environment of many urban logistics companies running in the same city. In the majority of cases, there is less or none coordination among them worsening traffic congestions. We believe that intelligent techniques are one of the key approaches that can aid to support smart and sustainable urban logistic applications. There are large open problems in the field of cooperative urban logistics that can greatly improve with the help of artificial intelligence. Some solutions are cited in this paper, but the overall conclusion is that there is still much work to be done.Giret Boggino, AS. (2019). Smart and sustainable urban logistic applications aided by intelligent techniques. Service Oriented Computing and Applications (Online). 13(3):185-186. https://doi.org/10.1007/s11761-019-00271-zS185186133Market reports (2019) Global last mile delivery market size, status and forecast 2019–2025. The Market reports. Report code : 1362721, pp 1–114Xiao Z, Wang JJ, Lenzer J, Sun Y (2017) Understanding the diversity of final delivery solutions for online retailing: a case of Shenzhen, China. In: World conference on transport research—WCTR 2016 Shanghai. Transportation Research Procedia, vol 25, pp 985–998, 2017. 10–15 July 2016Gonzalez-Feliu J, Semet F, Routhier JL (2014) Sustainable urban logistics: concepts, methods and information systems. Springer, BerlinMacharis C, Melo S (2011) City distribution and urban freight transport: multiple perspectives. Edward Elgar Publishing, CheltenhamPagell M, Wu Z (2009) Building a more complete theory of sustainable supply chain management using case studies of 10 exemplars. J Supply Chain Manag 45:37–56Morana J, Gonzalez-Feliu J (2015) A sustainable urban logistics dashboard from the perspective of a group of operational managers. Manag Res Rev 38(10):1068–1085Gunasekaran A, Kobu B (2007) Performance measures and metrics in logistics and supply chain management: a review of recent literature (1995–2004) for research and applications. Int J Prod Res 45:2819–2840Griffis SE, Goldsby TJ, Cooper M, Closs DJ (2007) Aligning logistics performance measures to the information needs of the firm. J Bus Logist 48:35–56Alonso-Mora J, Samaranayake S, Wallar A, Frazzoli E, Rus D (2017) On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment. Proc Natl Acad Sci 114(3):462–467Gentile G, Noekel K (2016) Modeling public transport passenger flows in the era of intelligent transport systems. Springer, BerlinNeirotti P, De Marco A, Cagliano AC, Mangano G, Scorrano F (2014) Current trends in smart city initiatives: some stylised facts. Cities 38:25–36Chatterjee R (2016) Optimizing last mile delivery using public transport with multiagent based control. Master thesis, pp 1–59Skiver RL, Godfrey M (2017) Crowdserving: a last mile delivery method for brickand—mortar retailers. Glob J Bus Res 11(2):67–77Brüning M, Schönewolf W (2011) Freight transport system for urban shipment and delivery. In: IEEE forum on integrated and sustainable transportation systems, Vienna, pp 136–14
Children and older adults exhibit distinct sub-optimal cost-benefit functions when preparing to move their eyes and hands
"© 2015 Gonzalez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited"Numerous activities require an individual to respond quickly to the correct stimulus. The provision of advance information allows response priming but heightened responses can cause errors (responding too early or reacting to the wrong stimulus). Thus, a balance is required between the online cognitive mechanisms (inhibitory and anticipatory) used to prepare and execute a motor response at the appropriate time. We investigated the use of advance information in 71 participants across four different age groups: (i) children, (ii) young adults, (iii) middle-aged adults, and (iv) older adults. We implemented 'cued' and 'non-cued' conditions to assess age-related changes in saccadic and touch responses to targets in three movement conditions: (a) Eyes only; (b) Hands only; (c) Eyes and Hand. Children made less saccade errors compared to young adults, but they also exhibited longer response times in cued versus non-cued conditions. In contrast, older adults showed faster responses in cued conditions but exhibited more errors. The results indicate that young adults (18 -25 years) achieve an optimal balance between anticipation and execution. In contrast, children show benefits (few errors) and costs (slow responses) of good inhibition when preparing a motor response based on advance information; whilst older adults show the benefits and costs associated with a prospective response strategy (i.e., good anticipation)
Storm/Substorm Signatures in the Outer Belt
The response of the ring current region is compared for periods of storm and substorm activity, with an attempt to isolate the contributions of both processes. The authors investigate CRRES particle data in an overview format that allows the display of long-term variations of the outer radiation belt. They compare the evolution of the ring current population to indicators of storm (Dst) and substorm (AE) activity and examine compositional changes. Substorm activity leads to the intensification of the ring current at higher L (L {approximately} 6) and lower ring current energies compared to storms (L {approximately} 4). The O{sup +}/H{sup +} ratio during substorms remains low, near 10%, but is much enhanced during storms (can exceed 100%). They conclude that repeated substorms with an AE {approximately} 900 nT lead to a {Delta}Dst of {approximately} 30 nT, but do not contribute to Dst during storm main phase as substorm injections do not form a symmetric ring current during such disturbed times
Prevalence of Plasmodium falciparum infection in asymptomatic rural Gabonese populations
<p>Abstract</p> <p>Background</p> <p>Malaria may be perennial or epidemic in sub-Saharan Africa, and its transmission may be stable or unstable, depending on the region. The prevalence of asymptomatic <it>Plasmodium falciparum </it>carriage is poorly documented in Gabon. A large survey of <it>P. falciparum </it>infection was conducted in asymptomatic individuals living in rural Gabon.</p> <p>Methods</p> <p>Two hundred and twenty-two villages were randomly selected in the nine administrative regions. With the participants' informed consent, blood samples were collected for thick and thin blood film examination after 20% Giemsa staining. Prevalence rates were calculated per village, per region and per ecosystem, and nationwide. Demographic risk factors were identified with STATA software version 9.0. Significance was assumed at p < 0.05.</p> <p>Results and discussion</p> <p>The prevalence of <it>P. falciparum </it>in adults was 6.2% (269/4342) nationwide, with a maximum of 37.2% in one village; a linear decrease was observed with increasing age (p = 0.045). Only 5% of the 399 children from forest areas tested positive. The prevalence was significantly higher in forest areas (7%) than in savannah (4%) and lakeland (2.5%). Within the forest region, the prevalence was significantly higher in forest grassland (10.9%) than in the mountain forest (3.5%), interior forest (6.8%) and north-eastern forest (4.5%).</p> <p>Conclusion</p> <p><it>Plasmodium falciparum </it>carriage remains high among adults in rural Gabon. Control measures must be adapted to the region and ecosystem. Routine treatment of asymptomatic individuals should be considered.</p
Mechanical Systems with Symmetry, Variational Principles, and Integration Algorithms
This paper studies variational principles for mechanical systems with symmetry and their applications to integration algorithms. We recall some general features of how to reduce variational principles in the presence of a symmetry group along with general features of integration algorithms for mechanical systems. Then we describe some integration algorithms based directly on variational principles using a
discretization technique of Veselov. The general idea for these variational integrators is to directly discretize Hamilton’s principle rather than the equations of motion in a way that preserves the original systems invariants, notably the symplectic form and, via a discrete version of Noether’s theorem, the momentum map. The resulting mechanical integrators are second-order accurate, implicit, symplectic-momentum algorithms. We apply these integrators to the rigid body and the double spherical pendulum to show that the techniques are competitive with existing integrators
Nanostructured Pt(NH3)4Cl2/SiO2 for nanomedicine: catalytic degradation of DNA in cancer cells
In vivo suppression of glioblastoma multiforme (GBM) in Wistar rats using silica-shelled biocatalytic Pt(NH3)4Cl2 nanoparticles is reported. These nanoparticles were synthesized by a sol-gel technique and characterized by SEM and HRTEM imaging. We confirmed morphological uniformity (30 nm) and surface acidity of the nanoparticles, respectively, by TEM imaging and FTIR spectral analysis. Interestingly, treatment of Wistar rats intraperitoneally inoculated with C6 cells using the biocatalysts resulted in considerable tumor shrinkage. Efficiency of the biocatalyst to shrink a tumor is superior to that by the commercial cytotoxic agent cisplatin. The tumor suppression property of Pt(NH3)4Cl2 nanoparticles is attributed to catalytic damage of DNA in C6 cells
Masked-Volume-Wise PCA and "reference Logan" illustrate similar regional differences in kinetic behavior in human brain PET study using [11C]-PIB
<p>Abstract</p> <p>Background</p> <p>Kinetic modeling using reference Logan is commonly used to analyze data obtained from dynamic Positron Emission Tomography (PET) studies on patients with Alzheimer's disease (AD) and healthy volunteers (HVs) using amyloid imaging agent <it>N</it>-methyl [<sup>11</sup>C]2-(4'-methylaminophenyl)-6-hydroxy-benzothiazole, [<sup>11</sup>C]-PIB. The aim of the present study was to explore whether results obtained using the newly introduced method, Masked Volume Wise Principal Component Analysis, MVW-PCA, were similar to the results obtained using reference Logan.</p> <p>Methods</p> <p>MVW-PCA and reference Logan were performed on dynamic PET images obtained from four Alzheimer's disease (AD) patients on two occasions (baseline and follow-up) and on four healthy volunteers (HVs). Regions of interest (ROIs) of similar sizes were positioned in different parts of the brain in both AD patients and HVs where the difference between AD patients and HVs is largest. Signal-to-noise ratio (SNR) and discrimination power (DP) were calculated for images generated by the different methods and the results were compared both qualitatively and quantitatively.</p> <p>Results</p> <p>MVW-PCA generated images that illustrated similar regional binding patterns compared to reference Logan images and with slightly higher quality, enhanced contrast, improved SNR and DP, without being based on modeling assumptions. MVW-PCA also generated additional MVW-PC images by using the whole dataset, which illustrated regions with different and uncorrelated kinetic behaviors of the administered tracer. This additional information might improve the understanding of kinetic behavior of the administered tracer.</p> <p>Conclusion</p> <p>MVW-PCA is a potential multivariate method that without modeling assumptions generates high quality images, which illustrated similar regional changes compared to modeling methods such as reference Logan. In addition, MVW-PCA could be used as a new technique, applicable not only on dynamic human brain studies but also on dynamic cardiac studies when using PET.</p
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