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Streams and rivers play an important role in the global carbon cycle. The origins of CO2 in streams are often poorly constrained or neglected, which is especially true for CO2 originating from heterotrophic metabolism in streambeds. We hypothesized that sediment movement will have a direct effect on stream metabolism, and thus, the aim of this study was to quantify the effect of moving bedforms on the production of CO2 in sandy streambeds. We conducted flume experiments where we used planar optodes to measure the distributions of O2 and CO2 under various streambed celerities. We combined these measurements with an assessment of bed morphodynamics and modeling to calculate O2 consumption and CO2 production rates. Our results indicate that sediment transport can strongly influence streambed metabolism and CO2 production. We found that bedform celerity controls the shape of the hyporheic zone and exchange flux, and is directly linked to the spatial and temporal distributions of O2 and CO2. It was also found that the most pronounced change in CO2 production occurred when the bed changed from stationary conditions to a slowly moving bed. A more gradual increase in O2 consumption and CO2 production rates was observed with further increase in celerity. Our study also points out that bedform movement causes hydraulic isolation between the moving and the non‐moving fraction of the streambed that can lead to a transient storage of CO2 in deeper sediments, which may be released in bursts during bed scour. Plain Language Summary: Streams play an important role in the global carbon cycle. Carbon is transported in streams and rivers toward the oceans, stored in the streambed, or emitted as the greenhouse gas CO2 to the atmosphere. Many studies try to link CO2 in streamwater and CO2 emission to flow conditions and CO2 import via groundwater while ignoring the role of microbial processes in sediments that also produce CO2. We performed lab experiments using an artificial stream channel and special sensors in the streambed to investigate the influence of moving sandy sediments on the distribution and production of CO2. We found that sediment movement controls the distribution of CO2, and that those distributions are influenced by the flow paths of the water flowing through the sediment. We also found that the production of CO2 and the flux of stream water entering the sediment increased with the speed of the sediment movement. Moreover, our results point out that the movement of the sediment disconnects the lower, non‐moving part of the sediment from the upper, moving part of the sediment. This can build up a storage of high CO2 concentrations in the deeper sediment, which may be released as bursts during events of streambed erosion. Key Points: Bedform celerity controls the spatial and temporal distribution of CO2 in stationary and moving sandy bedformsProduction of CO2 in sediments increases abruptly as the bed starts to move and more gradually with increasing bedform celerityBedform movement causes isolation of the non‐moving fraction of the streambed and increase in transient storage of CO2 in deeper sediments [ABSTRACT FROM AUTHOR]

Abstract Background The use of opioids has increased dramatically over the past several years in Israel. The aim of this study was to explore the trends of opioid consumption in Israel over a decade (2010–2020) stratified by socioeconomic status (SES), residence in the periphery, and ethnic background. Methods This cross-sectional study included all adult Maccabi Healthcare Services (MHS) patients who filled at least one prescription for opioids during the past decade. In order to standardize dosages and compare different opioid medications, we used the Morphine Milligram Equivalent (MME) conversion factor. We performed The Mann–Kendall test with autocorrelation correction to assess each trend. We then checked the differences between the trends with the Mann–Whitney test (for periphery) and the Kruskal Wallis (for SES and ethnic background). Results Between the years 2010–2020, 261,270 MHS members met the study's inclusion criteria. The proportions of opioids consumption were 23.9/1000 patients in 2010 and 27.6/1000 patients in 2020, representing a 15% increase. The average daily consumption of opioids was 4.6 and 10.5 MME in 2010 and 2020, respectively, an increase of 227%. The daily MME during 2020 was higher for residents of the periphery compared to non-periphery residents (daily MME of 14.0 compared to 10.1, respectively). Average daily MME increased gradually during the study period for all levels of SES; the values were highest for the low SES group and the lowest for the high SES group (daily MME in 2020 for the lowest, middle, and high SES groups were 15.2 vs. 11.8 vs. 6.7 respectively). Conclusions This study highlights that the primary concern in the increase of opioid use is the increasing dosages. The increase in the number of patients using opioids is also significant but to a minor extent. These phenomena disproportionately impact vulnerable populations. Education programs should be offered to physicians regarding the possible harms of long-term use of opioids. These programs should emphasize the risk factors associated with the development of opioid use disorder (OUD) and the caution needed when increasing dosages or switching to higher-potency drugs. Pain clinics and centers for rehabilitation for patients with chronic pain or OUD should be available, not only in central areas but also in the periphery of the country. These clinics and centers should use a holistic approach and a multidisciplinary team that includes specialists in pain and addiction. They should be financially accessible for patients from low SES group and provide solutions in multiple languages.

Communications and range estimation between formation members are essential functions of formation flying. The inherent features of laser free-space link: small weight and mass, power efficiency, broadband, high precision, availability of state-of-art components, make it a very attractive candidate for micro-satellite formation flying missions. A single two-way laser link, performing simultaneously communication and range estimation functions between formation spacecraft is being investigated in the framework of Broadband Laser Inter-Satellite Link (BLSIL), a joint Israeli-German applied research project. A unique technique of pointing control system for an inter-satellite laser communication and ranging link is presented. In this system, the same laser is used both as a beacon and as a transmitter. To maximize the traffic capacity of the link, the beamwidth is controlled from broad in the acquisition stage, to narrow in the tracking stage. Laser link pointing control presents difficult demands from the beam pointing precision. To establish and maintain the laser link between the satellites in orbit, pointing control must be fast and precise. A hierarchic two-level system control is proposed. The lower level controls the gimbals of the optical head of the electro-optical transceiver; the higher level is a fast closed loop that simultaneously controls the beamwidth and direction. It is the primary subject of the paper. Initial pointing acquisition assumes exchange of position-related information between the satellites to establish the initial line of sight (LOS). After initial acquisition a cooperative extremum-seeking algorithm is used for the fast higher level closed loop control. The paper gives a detailed description of the control algorithms. Representative simulations are presented.

Free space optical communication between satellites networked together can make possible high speed communication between different places on Earth. The basic free space optical communication network includes at least two satellites. In order to communicate between them, the transmitter satellite must track the beacon of the receiver satellite and point the information optical beam in its direction. The pointing systems for laser satellite communication suffer during tracking from vibration due to electronic noise, background radiation from interstellar objects such as Sun, Moon, Earth, and Stars in the tracking field of view, and mechanical impact from satellite internal and external sources. Due to vibrations the receiver receives less power. This effect limits the system bandwidth for given bit error rate (BER). In this research we derive an algorithm to maximize the communication system bandwidth using the transmitter telescope gain as a free variable based on the vibration statistics model and the system parameters. Our model makes it possible to adapt the bandwidth and transmitter gain to change of vibration amplitude. We also present an example of a practical satellite network which includes a direct detection receiver with an optical amplifier. A bandwidth improvement of three orders of magnitude is achieved in this example for certain conditions, as compared with an unoptimized system.

An important aspect in satellite optical communication is to obtain minimum bit error rate (BER) using minimum power. This aim can be achieved with very small transmitter beam divergence angles. The disadvantages of too narrow divergence angle is that the transmitter beam may sometimes miss the receiver satellite, due to pointing vibrations. A mathematical model of communication and tracking systems that optimize the BER as function of the transmitter gain is derived.

Optical space communication from satellite to ground or air to air consists of clouds as part of communication channels. Propagation of optical pulses through clouds causes widening and deformation in the time domain and attenuation of the pulse radiant power. These effects decrease the received signal and limit the information bandwidth of the communication system. Having dealt with the other effects previously, here we concentrate on pulse broadening in the time domain. We derive a mathematical model of an adaptive optical communication system with a multiscattering channel (atmospheric cloud). We use knowledge about the impulse response function of the cloud to adapt the communication parameters to the transfer function of the cloud. The communication system includes a receiver and a transmitter. We adapted the transmitter to atmospheric conditions by changing the bit error rate. One can adapt the receiver to the atmospheric condition by changing the parameters of the detector and the filter. An example for a practical communication system between a low Earth orbit satellite and a ground station cover by cloud is given. Comparison and analysis of an adaptive and semiadaptive system with cloud channels are presented. Our conclusion is that in some cases only by such adaptive methods is optical communication possible. Key words: Adaptive optical communication, free-space communication, adaptive filter, optical pulse widening, multiscattering.

Monitoring, probing, and sensing characteristics of aerosol clouds is difficult and complicated. Probing the characteristics of aerosols is most useful in the chemical and microelectronic industry for processing control of aerosols and emulsion, decreasing bit error rate in adaptive optical communication systems, and in acquiring data for atmospheric science and environment quality. We present a new mathematical and optical engineering model for monitoring characteristics of aerosol clouds. The model includes the temporal transfer function of aerosol clouds as a variable parameter in an electro-optic oscillator. The frequency of the oscillator changes according to changes in the characteristics of the clouds (density, size distribution, physical thickness, the medium and the particulate refractive indices, and spatial distribution). It is possible to measure only one free characteristic at a given time. An example of a practical system for monitoring the density of aerosol clouds is given. The frequency of the oscillator changes from 1.25 to 0.43 MHz for changes in aerosol density from 2000 to 3000 particulates [cm.sup.-3]. The advantages of this new method compared with the transmissometer methods are (a) no necessity for line-of-sight measurement geometry, (b) accurate measurement of high optical thickness media is possible, (c) under certain conditions measurements can include characteristics of aerosol clouds related to light scatter that cannot be or are difficult to measure with a transmissometer, and (d) the cloud bandwidth for free space optical communication is directly measurable. Key words: Aerosols, monitoring and probing, multiple scatter, electro-optic oscillator, clouds, light scatter, Monte Carlo simulation.

Decreased signal-to-noise ratio and maximum bit rate as well as increased in error probability in optical digital communication are caused by particulate light scatter in the atmosphere and in space. Two effects on propagation of laser pulses are described: spatial widening of the transmitted beam and attenuation of pulse radiant power. Based on these results a model for reliability of digital optical communication in a particulate-scattering environment is presented. Examples for practical communication systems are given. An adaptive method to improve and in some cases to make possible communication is suggested. Comparison and analysis of two models of communication systems for the particulate-scattering channel are presented: a transmitter with a high bit rate and a receiver with an avalanche photodiode and a transmitter with a variable bit rate and a new model for an adaptive circuit in the receiver. An improvement of more than 7 orders of magnitude in error probability under certain conditions is possible with the new adaptive system model.

Introduction Smoking is the leading preventable cause of death and illness globally. There is conflicting evidence regarding the association between quitting rates and partners’ smoking status. It is thought that spouses influence one another’s health habits, including smoking. This study aims to evaluate this association in patients who made a smoking cessation attempt with pharmacotherapy. Methods For this Israeli nationwide retrospective cohort study, we randomly selected patients who filled a prescription for varenicline as part of their smoking cessation process and were partnered. The participants were asked to complete a questionnaire 26–52 weeks after the first varenicline purchase. The independent variables were the partner’s smoking status at the beginning of the smoking cessation process and while answering the questionnaire. The outcome was a success in the quitting process. Results In all, 226 (50%) participants had partners who smoked at the beginning of the quitting process, and 230 (50%) had non-smoking partners; 178 (39%) participants reported successful smoking cessation. There was a significant difference in success rates depending on partners’ smoking status at the end of the process, with success rates of 39% with a non-smoking partner, 76% with a partner who also stopped smoking, and 31% with a partner who continued smoking (p