Is a municipal socio-economic ranking more influential than vaccination on daily growth in COVID-19 infection rate?

AbstractNumerous studies have attempted to identify potential risk-factors associated with COVID-19 infection, including inter alia: age, diet, higher population density, and the quality and availability of health services. The objective of the current study is to analyze the weight of four covariates on a daily infection rate from SARS-COV2 virus. The method used is regression analysis, where each variable is converted to the standard normal distribution function. Results demonstrate that of the four investigated covariates, vaccination and population size have the highest weights. Given the empirical analysis, the most efficient way to achieve a reduction in the spread of the pandemic is via appropriate vaccination programs

Is a municipal socio-economic ranking more influential than vaccination on daily growth in COVID-19 infection rate?

Numerous studies have attempted to identify potential risk-factors associated with COVID-19 infection, including inter alia: age, diet, higher population density, and the quality and availability of health services. The objective of the current study is to analyze the weight of four covariates on a daily infection rate from SARS-COV2 virus. The method used is regression analysis, where each variable is converted to the standard normal distribution function. Results demonstrate that of the four investigated covariates, vaccination and population size have the highest weights. Given the empirical analysis, the most efficient way to achieve a reduction in the spread of the pandemic is via appropriate vaccination programs. Numerous studies have attempted to identify potential risk-factors associated with COVID-19 infection, including inter alia: age, diet, higher population density, and the quality and availability of health services. The contributions of this article are threefold: We use a unique method to test the COVID-19 vaccine effectiveness. We follow the COVID-19 infection growth rate in each of the 171 Israeli municipalities, starting from 11 March 2020 (the first documentation of COVID-19 cases) until 21 September 2021, where COVID-19 vaccinations were available starting from 20 December 2020.A unique feature of Israel is the early initiation of a nationwide vaccination campaign, which resulted in the full vaccination (i.e. receipt of two vaccine doses) in more than half the population by the end of March 2021. Consequently, Israel provides an appropriate case study to examine the efficiency of the vaccination.The conventional empirical model uses different units of measurement of each explanatory variable. Unlike previous studies, we estimate a model with identical units of measurement, namely one standard deviation of each independent variable. This target is achieved by normalizing all the variables in the regression model. We use a unique method to test the COVID-19 vaccine effectiveness. We follow the COVID-19 infection growth rate in each of the 171 Israeli municipalities, starting from 11 March 2020 (the first documentation of COVID-19 cases) until 21 September 2021, where COVID-19 vaccinations were available starting from 20 December 2020. A unique feature of Israel is the early initiation of a nationwide vaccination campaign, which resulted in the full vaccination (i.e. receipt of two vaccine doses) in more than half the population by the end of March 2021. Consequently, Israel provides an appropriate case study to examine the efficiency of the vaccination. The conventional empirical model uses different units of measurement of each explanatory variable. Unlike previous studies, we estimate a model with identical units of measurement, namely one standard deviation of each independent variable. This target is achieved by normalizing all the variables in the regression model. Findings suggest vaccination as the factor providing the highest contribution to projected infection growth rate decrease. They stress the high importance of vaccination, and provide further support of vaccination efforts.</p

Logic operations in memory using a memristive Akers array

In-memory computation is one of the most promising features of memristive memory arrays. In this paper, we propose an array architecture that supports in-memory computation based on a logic array first proposed in 1972 by Sheldon Akers. The Akers logic array satisfies this objective since this array can realize any Boolean function, including bit sorting. We present a hardware version of a modified Akers logic array, where the values stored within the array serve as primary inputs. The proposed logic array uses memristors, which are nonvolatile memory devices with noteworthy properties. An Akers logic array with memristors combines memory and logic operations, where the same array stores data and performs computation. This combination opens opportunities for novel non-von Neumann computer architectures, while reducing power and enhancing memory bandwidth

Rotation and Negative Torque in Electrodynamically Bound Nanoparticle Dimers

We examine the formation and concomitant rotation of electrodynamically bound dimers (EBD) of 150 nm diameter Ag nanoparticles trapped in circularly polarized focused Gaussian beams. The rotation frequency of an EBD increases linearly with the incident beam power, reaching mean values of ∼4 kHz for relatively low incident powers of 14 mW. Using a coupled-dipole/effective polarizability model, we reveal that retardation of the scattered fields and electrodynamic interactions can lead to a “negative torque” causing rotation of the EBD in the direction opposite to that of the circular polarization. This intriguing opposite-handed rotation due to negative torque is clearly demonstrated using electrodynamics-Langevin dynamics simulations by changing particle separations and thus varying the retardation effects. Finally, negative torque is also demonstrated in experiments from statistical analysis of the EBD trajectories. These results demonstrate novel rotational dynamics of nanoparticles in optical matter using circular polarization and open a new avenue to control orientational dynamics through coupling to interparticle separation

Reactive optical matter: light-induced motility in electrodynamically asymmetric nanoscale scatterers

From Newton’s third law, which is known as the principle of actio et reactio1, we expect the forces between interacting particles to be equal and opposite for closed systems. Otherwise, “nonreciprocal” forces can arise.2 This has been shown theoretically in the interaction between dissimilar optically trapped particles that are mediated by an external field.3 As a result, despite the incident external field not having a transverse component of momentum, the particle pair experiences a force in a direction that is transverse to the light propagation direction.3,4 In this letter, we directly measure the net nonreciprocal forces in electrodynamically interacting asymmetric nanoparticle dimers and nanoparticle structures that are illuminated by plane waves and confined to pseudo one-dimensional geometries. We show via electrodynamic theory and simulations that interparticle interactions cause asymmetric scattering from heterodimers. Therefore, the putative nonreciprocal forces are actually a consequence of momentum conservation. Our study demonstrates that asymmetric scatterers exhibit directed motion due to the breakdown of mirror symmetry in their electrodynamic interactions with external fields