Optimal Policy Derivation for Transmission Duty-Cycle Constrained LPWAN

Low-power wide-area network (LPWAN) technologies enable Internet of Things (IoT) devices to efficiently and robustly communicate over long distances, thus making them especially suited for industrial environments. However, the stringent regulations on the usage of certain industrial, scientific, and medical bands in many countries in which LPWAN operate limit the amount of time IoT motes can occupy the shared bands. This is particularly challenging in industrial scenarios, where not being able to report some detected events might result in the failure of critical assets. To alleviate this, and by mathematically modeling LPWAN-based IoT motes, we have derived optimal transmission policies that maximize the number of reported events (prioritized by their importance) while still complying with current regulations. The proposed solution has been customized for two widely known LPWAN technologies: 1) LoRa and 2) Sigfox. Analytical results reveal that our solution is feasible and performs remarkably close to the theoretical limit for a wide range of network activity patterns

Absorption efficiency of gold nanorods determined by quantum dot fluorescence thermometry

In this work quantum dot fluorescence thermometry, in combination with double-beam confocal microscopy, has been applied to determine the thermal loading of gold nanorods when subjected to an optical excitation at the longitudinal surface plasmon resonance. The absorbing/heating efficiency of low (≈3) aspect ratio gold nanorods has been experimentally determined to be close to 100%, in excellent agreement with theoretical simulations of the extinction, absorption, and scattering spectra based on the discrete dipole approximation

Gravity in the 3+1-Split Formalism II: Self-Duality and the Emergence of the Gravitational Chern-Simons in the Boundary

We study self-duality in the context of the 3+1-split formalism of gravity with non-zero cosmological constant. Lorentzian self-dual configurations are conformally flat spacetimes and have boundary data determined by classical solutions of the three-dimensional gravitational Chern-Simons. For Euclidean self-dual configurations, the relationship between their boundary initial positions and initial velocity is also determined by the three-dimensional gravitational Chern-Simons. Our results imply that bulk self-dual configurations are holographically described by the gravitational Chern-Simons theory which can either viewed as a boundary generating functional or as a boundary effective action.Comment: 25 pages; v2: minor improvements, references adde

Rotational velocities of low-mass stars in the Pleiades and Hyades

We have obtained high-resolution spectra of 89 M dwarf members of the Pleiades and Hyades and have derived radial velocities, H-alpha equivalent widths, and spectroscopic rotational velocities for these stars. Typical masses of the newly-observed Pleiades and Hyades stars are ~ 0.4 M_{\sun} and ~ 0.2 M_{\sun}, respectively. We combine our new observations with previously published data to explore the rotational evolution of young stars with M < 0.4 M_\sun. The average rotation rate in the Hyades (age 600 Myr) is about 0.4 that of the Pleiades (110 Myr), and the mean equivalent widths of H-alpha are also lower. As found in previous studies, the correlation between rotation and chromospheric activity is identical in both clusters, implying that the lower activity in the Hyades is a result of the lower rotation rates. We show that a simple scaling of the Pleiades rotational distribution for M \leq 0.4 M_{\sun}, corrected for the effects of structural evolution, matches that of the Hyades if the average angular momentum loss from the Pleiades to the Hyades age is factor of \approx 6. This suggests that the distribution of initial angular momenta and disk-locking lifetimes for the lowest mass stars was similar in both clusters. We argue that this result provides further evidence for a saturation of the angular momentum loss rate at high rotational velocities.Comment: 22 pages, 11 figures, accepted for publication in The Astronomical Journal, tentatively scheduled for March 200

A Bayesian approach for estimating the uncertainty on the contribution of nitrogen fixation and calculation of nutrient balances in grain legumes

Background: The proportion of nitrogen (N) derived from the atmosphere (Ndfa) is a fundamental component of the plant N demand in legume species. To estimate the N benefit of grain legumes for the subsequent crop in the rotation, a simplified N balance is frequently used. This balance is calculated as the difference between fixed N and removed N by grains. The Ndfa needed to achieve a neutral N balance (hereafter ) is usually estimated through a simple linear regression model between Ndfa and N balance. This quantity is routinely estimated without accounting for the uncertainty in the estimate, which is needed to perform formal statistical inference about . In this article, we utilized a global database to describe the development of a novel Bayesian framework to quantify the uncertainty of . This study aimed to (i) develop a Bayesian framework to quantify the uncertainty of , and (ii) contrast the use of this Bayesian framework with the widely used delta and bootstrapping methods under different data availability scenarios. Results: The delta method, bootstrapping, and Bayesian inference provided nearly equivalent numerical values when the range of values for Ndfa was thoroughly explored during data collection (e.g., 6–91%), and the number of observations was relatively high (e.g., ). When the Ndfa tested was narrow and/or sample size was small, the delta method and bootstrapping provided confidence intervals containing biologically non-meaningful values (i.e.  100%). However, under a narrow Ndfa range and small sample size, the developed Bayesian inference framework obtained biologically meaningful values in the uncertainty estimation. Conclusion: In this study, we showed that the developed Bayesian framework was preferable under limited data conditions ─by using informative priors─ and when uncertainty estimation had to be constrained (regularized) to obtain meaningful inference. The presented Bayesian framework lays the foundation not only to conduct formal comparisons or hypothesis testing involving , but also to learn about its expected value, variance, and higher moments such as skewness and kurtosis under different agroecological and crop management conditions. This framework can also be transferred to estimate balances for other nutrients and/or field crops to gain knowledge on global crop nutrient balances.Fil: Palmero, Francisco. Kansas State University; Estados UnidosFil: Hefley, Trevor J.. Kansas State University; Estados UnidosFil: Lacasa, Josefina. Kansas State University; Estados UnidosFil: Almeida, Luiz Felipe. Kansas State University; Estados UnidosFil: Haro, Ricardo J.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Garcia, Fernando Oscar. No especifíca;Fil: Salvagiotti, Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Oliveros; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Ciampitti, Ignacio Antonio. Kansas State University; Estados Unido

Heat in optical tweezers

Laser-induced thermal effects in optically trapped microspheres and single cells have been investigated by Luminescence Thermometry. Thermal spectroscopy has revealed a non-localized temperature distribution around the trap that extends over tens of microns, in agreement with previous theoretical models. Solvent absorption has been identified as the key parameter to determine laser-induced heating, which can be reduced by establishing a continuous fluid flow of the sample. Our experimental results of thermal loading at a variety of wavelengths reveal that an optimum trapping wavelength exists for biological applications close to 820 nm. This has been corroborated by a simultaneous analysis of the spectral dependence of cellular heating and damage in human lymphocytes during optical trapping. Minimum intracellular heating, well below the cytotoxic level (43 °C), has been demonstrated to occur for optical trapping with 820 nm laser radiation, thus avoiding cell damage

Noncommutative quantum mechanics and Bohm's ontological interpretation

We carry out an investigation into the possibility of developing a Bohmian interpretation based on the continuous motion of point particles for noncommutative quantum mechanics. The conditions for such an interpretation to be consistent are determined, and the implications of its adoption for noncommutativity are discussed. A Bohmian analysis of the noncommutative harmonic oscillator is carried out in detail. By studying the particle motion in the oscillator orbits, we show that small-scale physics can have influence at large scales, something similar to the IR-UV mixing

Duration of heat treatment and true digestibility of amino acids in meat meal for Leghorn cockerels

Knowledge of the true digestibility of amino acids in the ingredients of a poultry ration is important in order to use them properly, especially the proteinic ingredients that have been heated during processing, such as meat meal. Protein solubility is a good indicator of heat damage. To estimate true digestibility, Leghorn White cockerels were fasted for 24 h and then force fed with meat meal autoclaved at 121°C and 1.5 kg/cm2 for 0, 15, 30, 45 and 60 minutes. A correction for endogenous amino acids was included. Nitrogen was determined by micro Kjeldahl; protein solubility by the methods of 2% KOH and coomassie blue; amino acids concentrations were also determined by HPLC. Treatments had an effect (P&lt;.05) on meat meal protein solubility, means being 89% and 84% for the KOH and coomassie blue methods, respectively. However, protein solubility increased until 30 minutes and then decreased according to the KOH method, whereas it increased until 15 minutes (P&lt;.05) and then remained constant by the coomassie blue method. Autoclaving had an effect on true digestibility of all amino acids, except methionine. There was a high and significant correlation (0.81) between protein solubility by the KOH method and true digestibility of amino acids

The Physics of turbulent and dynamically unstable Herbig-Haro jets

The overall properties of the Herbig-Haro objects such as centerline velocity, transversal profile of velocity, flow of mass and energy are explained adopting two models for the turbulent jet. The complex shapes of the Herbig-Haro objects, such as the arc in HH34 can be explained introducing the combination of different kinematic effects such as velocity behavior along the main direction of the jet and the velocity of the star in the interstellar medium. The behavior of the intensity or brightness of the line of emission is explored in three different cases : transversal 1D cut, longitudinal 1D cut and 2D map. An analytical explanation for the enhancement in intensity or brightness such as usually modeled by the bow shock is given by a careful analysis of the geometrical properties of the torus.Comment: 17 pages, 10 figures. Accepted for publication in Astrophysics & Spac