107 research outputs found
Trajectory-based interpretation of Young's experiment, the Arago-Fresnel laws and the Poisson-Arago spot for photons and massive particles
We present a trajectory based interpretation for Young's experiment, the
Arago-Fresnel laws and the Poisson-Arago spot. This approach is based on the
equation of the trajectory associated with the quantum probability current
density in the case of massive particles, and the Poynting vector for the
electromagnetic field in the case of photons. Both the form and properties of
the evaluated photon trajectories are in good agreement with the averaged
trajectories of single photons observed recently in Young's experiment by
Steinberg's group at the University of Toronto. In the case of the
Arago-Fresnel laws for polarized light, the trajectory interpretation presented
here differs from those interpretations based on the concept of "which-way" (or
"which-slit") information and quantum erasure. More specifically, the
observer's information about the slit that photons went through is not relevant
to the existence of interference; what is relevant is the form of the
electromagnetic energy density and its evolution, which will model consequently
the distribution of trajectories and their topology. Finally, we also show that
the distributions of end points of a large number of evaluated photon
trajectories are in agreement with the distributions measured at the screen
behind a circular disc, clearly giving rise to the Poisson-Arago spot.Comment: 8 pages, 5 figure
Actuality and perspectives of the wood industry development in western balkan countries
Wood mass represents a significant potential for the countries of the Adriatic region. Considering its geographic distribution, significant differences can be noticed. Those differences are mainly manifested regarding its quality and quantity. The aim of this paper is to emphasize the importance of territorial distribution of the wood mass from the aspect of its use in the wood industry. The result of the research procedure is to point out certain parts of the Adriatic region, where the development of the wood industry can be promoted
Digital twin control of multi-axis wood CNC machining center based on LinuxCNC
Abstrack:
This paper presents an application of an open architecture control system implemented on a multi-axis wood computer numerical control milling machining center, as a digital twin control. The development of the digital twin control system was motivated by research and educational requirements, especially in the field of configuring a new control system by “virtual commissioning”, enabling the validation of the developed controls, program verification, and analysis of the machining process and monitoring. The considered wood computer numerical control (CNC) machining system is supported by an equivalent virtual machine in a computer-aided design and computer-aided manufacturing (CAD/CAM) environment, as well as in the control system, as a digital twin. The configured virtual machines are used for the verification of the machining program and programming system via machining simulation, which is extremely important in multi-axis machining. Several test wood workpieces were machined to validate the effectiveness of the developed control system based on LinuxCNC
Future directions in international financial integration research. A crowdsourced perspective
This paper is the result of a crowdsourced effort to surface perspectives on
the present and future direction of international finance. The authors are
researchers in financial economics who attended the INFINITI 2017 conference
in the University of Valencia in June 2017 and who participated in the
crowdsourcing via the Overleaf platform. This paper highlights the actual
state of scientific knowledge in a multitude of fields in finance and proposes
different directions for future research
The comparative responsiveness of Hospital Universitario Princesa Index and other composite indices for assessing rheumatoid arthritis activity
Objective
To evaluate the responsiveness in terms of correlation of the Hospital Universitario La Princesa Index (HUPI) comparatively to the traditional composite indices used to assess disease activity in rheumatoid arthritis (RA), and to compare the performance of HUPI-based response criteria with that of the EULAR response criteria.
Methods
Secondary data analysis from the following studies: ACT-RAY (clinical trial), PROAR (early RA cohort) and EMECAR (pre-biologic era long term RA cohort). Responsiveness was evaluated by: 1) comparing change from baseline (Delta) of HUPI with Delta in other scores by calculating correlation coefficients; 2) calculating standardised effect sizes. The accuracy of response by HUPI and by EULAR criteria was analyzed using linear regressions in which the dependent variable was change in global assessment by physician (Delta GDA-Phy).
Results
Delta HUPI correlation with change in all other indices ranged from 0.387 to 0.791); HUPI's standardized effect size was larger than those from the other indices in each database used. In ACT-RAY, depending on visit, between 65 and 80% of patients were equally classified by HUPI and EULAR response criteria. However, HUPI criteria were slightly more stringent, with higher percentage of patients classified as non-responder, especially at early visits. HUPI response criteria showed a slightly higher accuracy than EULAR response criteria when using Delta GDA-Phy as gold standard.
Conclusion
HUPI shows good responsiveness in terms of correlation in each studied scenario (clinical trial, early RA cohort, and established RA cohort). Response criteria by HUPI seem more stringent than EULAR''s
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
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