Sequential Generalized Likelihood Ratio Tests for Online Item Monitoring

The study presents statistical procedures that monitor functioning of items over time. We propose generalized likelihood ratio tests that surveil multiple item parameters and implement with various sampling techniques to perform continuous or intermittent monitoring. The procedures examine stability of item parameters across time and inform compromise as soon as they identify significant parameter shift. The performance of the monitoring procedures was validated using simulated and real assessment data. The empirical evaluation suggests that the proposed procedures perform adequately well in identifying the parameter drift. They showed satisfactory detection power and gave timely signals while regulating the error rates reasonably low. The procedures also showed superior performance when compared with the existent methods. The empirical findings suggest that multivariate parametric monitoring can provide an efficient and powerful control tool for maintaining the quality of items. The procedures allow joint monitoring of multiple item parameters and achieve sufficient power by dint of likelihood-ratio tests. Based on the findings from the empirical experimentation, we suggest some practical strategies for performing online item monitoring.

A high-luminosity superconducting twin e+e- linear collider with energy recovery

Superconducting technology makes it possible to build a high energy e+e- linear collider with energy recovery (ERLC) and reusable beams. To avoid parasitic collisions inside the linacs, a twin (dual) LC is proposed. In this article, I consider the principle scheme of the collider and estimate the achievable luminosity, which is limited by collision effects and available power. Such a collider can operate in a duty cycle (DC) and in a continuous (CW) modes, if sufficient power. With current SC Nb technology (T = 1.8 K, f RF = 1.3 GHz, used for ILC) and with power P = 100 MW, a luminosity L ∼ 0.33 × 1036 cm-2 s-1 is possible at the Higgs factory with 2E 0 = 250 GeV. Using superconductors operating at 4.5 K with high Q 0 values, such as Nb3Sn, and f RF = 0.65 GHz, the luminosity can reach L ∼ 1.4 × 1036 cm-2 s-1 at 2EE0 = 250 GeV (with P = 100 MW) and L ∼ 0.8 × 1036 cm-2 s-1 at 2E 0 = 500 GeV (with P = 150 MW), which is almost two orders of magnitude greater than at the ILC, where the beams are used only once. This technology requires additional efforts to obtain the required parameters and reliably operation. Such a collider would be the best machine for precision Higgs studies, including the measurement of Higgs self-coupling.

Antibiotic prophylaxis for prevention against Lyme disease following tick bite: an updated systematic review and meta-analysis

Background In areas where Lyme disease is endemic, bites from ticks are common, but no vaccine is currently available against Lyme disease for humans. Therefore, the feasibility of using antibiotic prophylaxis to prevent Lyme disease after a tick bite is worth further exploration. Previous meta-analyses lack sufficient power to demonstrate the efficacy of about antibiotic prophylaxis for the prevention of Lyme disease following a tick bite. In this study, we explored more precise evidence and attempted to identify and update optimum treatment strategies. Methods We searched PubMed, Embase, and the Cochrane Library for studies until March 23, 2021. We included studies if the enrolled patients were randomly allocated to a treatment or control group within 72 h following a tick bite and had no clinical evidence of Lyme disease at enrolment. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were followed for data abstraction. Two authors (GZZ and XX) independently reviewed the abstracts and identified articles for detailed assessment. We used a random-effects model to calculate the pooled results and reported the 95% confidence interval (CI). Study quality was assessed using a modified Jadad scale, and publication bias was assessed using Egger’s test. We calculated the risk ratio (RR) for the rates of unfavorable events in patients who received intervention versus the control group. This study is registered with PROSPERO, number CRD42021245002. Results Six studies (3,766 individuals) were included. The pooled rate of unfavorable events in persons receiving treatment and the control group were 0.4% (95%CI: 0.1–1.1%) and 2.2% (95%CI: 1.6–3.0%), respectively. The pooled RR was 0.38 (95%CI: 0.22–0.66). Subgroup analysis revealed that the pooled RR was 0.29 (95%CI: 0.14–0.60) in the single-use 200-mg doxycycline group; 0.28 (95%CI: 0.05–1.67) in a 10-day course group (Amoxicillin, Penicillin or tetracycline); and 0.73 (95%CI: 0.25–2.08) in a topical antibiotic treatment group (Azithromycin). Conclusions The available evidence supports the use of antibiotics for the prevention of Lyme disease, and reveals advantages of using single-dose; however, further confirmation is needed.

Construct Validity in Accruals Quality Research

A large body of empirical research in accounting investigates the causes and consequences of accruals quality, reaching numerous influential conclusions. Yet little work has been done to systematically evaluate the validity of the underlying measures of accruals quality. We evaluate these measures using three criteria: (i) Is the measure unaffected by the underlying economic determinants of accruals? (ii) Does the measure consistently reflect errors in accruals? and (iii) Does the measure facilitate tests with sufficient power to detect plausible variation in accrual errors? Using a combination of theoretical modeling and numerical simulations, we show that all measures fail at least one of these criteria. Our evaluation provides new interpretations of existing research and guides the choice of measures and the interpretation of results in future research.

Piezoelectricity and Flexoelectricity from an Energy Harvesting Perspective: Nanogenerators

Energy harvesting is the process by which energy can be obtained from external sources and used for wearable electronics and wireless sensor networks. Piezoelectric nanogenerators are energy harvesting devices that convert mechanical energy into electric energy by using nanostructured materials. This article summarizes work to date on piezoelectric nanogenerators, starting with the basic theory of piezo- and flexo-electricity and moving through reports on nanogenerators using nanostructures, flexible substrates and alternative materials. A sufficient power generated from nanogenerators suggests feasible applications for either power sources or strain sensors of highly integrated nanodevices. Further improvements in nanogenerators holds promise for the development of self-powered implantable and wearable electronics.

A Review of Smart Energy Metering System Projects

The rule of thumb dictates that for any country to have a stable and sufficient power supply, there must be at least a thousand Megawatts of electricity for every one million population. However, many developing countries generate far less than the population demand. Despite not generating enough, enormous electrical power loss, energy theft, and unpaid bills are major problems bedeviling the power distribution companies. A fundamental process in the electricity cycle is energy metering from power generation to distribution and consumption. For decades now, manual (or conventional) energy meters are used to estimate every end-user's energy consumption. But there are lots of setbacks to these meters. These meters were unable to solve the problems of power loss and theft, giving necessity to developing a metering system that will serve as a solution to all issues emanating from the consumer end. The past decade saw many developments of such meters, where all are based on the internet of things (IoT) technology. Such meters are called – by the early developers – a smart energy metering system (SEMS), or simply, a Smart Meter. While there have been several reviews on SEMS, most were found to be based on the instant billing capabilities of SEMS, system development, and the wireless communication protocols of the systems. This review focuses on individual components of SEMS with particular attention to the different types and modes of sensors used for other applications. It analyzes various SEMS designs, microcontrollers, sensors, modules, transducers, communication protocols, data storage accuracy, and maximum power capability. Also discussed are the achievements and weaknesses of the designs, some future research challenges, and open issues in the implementation of SEMS.

The evolving role and utility of off-label drug use in multiple myeloma

The treatment landscape for multiple myeloma (MM) has dramatically changed over the last three decades, moving from no US Food and Drug Administration approvals and two active drug classes to over 19 drug approvals and at least eight different active classes. The advances seen in MM therapy have relied on both a structured approach to obtaining new labels and cautious off-label drug use. Although there are country and regional differences in drug approval processes, many of the basic principles behind off-label drug use in MM can be summarized into four main categories: 1) use of a therapy prior to the current approval regulations; 2) widespread use of a therapy following the release of promising clinical trial results but prior to drug approval; 3) use of a cheap therapy supported by clinical safety and efficacy data but without commercial backing; and 4) niche therapies for small well-defined patient populations where large clinical trials with sufficient power may be difficult to perform. This review takes a historical approach to discuss how off-label drug use has helped to shape the current treatment approach for MM.

An On-Demand Charging for Connected Target Coverage in WRSNs Using Fuzzy Logic and Q-Learning

In wireless rechargeable sensor networks (WRSNs), a mobile charger (MC) moves around to compensate for sensor nodes’ energy via a wireless medium. In such a context, designing a charging strategy that optimally prolongs the network lifetime is challenging. This work aims to solve the challenges by introducing a novel, on-demand charging algorithm for MC that attempts to maximize the network lifetime, where the term “network lifetime” is defined by the interval from when the network starts till the first target is not monitored by any sensor. The algorithm, named Fuzzy Q-charging, optimizes both the time and location in which the MC performs its charging tasks. Fuzzy Q-charging uses Fuzzy logic to determine the optimal charging-energy amounts for sensors. From that, we propose a method to find the optimal charging time at each charging location. Fuzzy Q-charging leverages Q-learning to determine the next charging location for maximizing the network lifetime. To this end, Q-charging prioritizes the sensor nodes following their roles and selects a suitable charging location where MC provides sufficient power for the prioritized sensors. We have extensively evaluated the effectiveness of Fuzzy Q-charging in comparison to the related works. The evaluation results show that Fuzzy Q-charging outperforms the others. First, Fuzzy Q-charging can guarantee an infinite lifetime in the WSRNs, which have a sufficient large sensor number or a commensurate target number. Second, in other cases, Fuzzy Q-charging can extend the time until the first target is not monitored by 6.8 times on average and 33.9 times in the best case, compared to existing algorithms.

Severe Sepsis: The Fragile Anatomy of Crude Mortality

Clinical trials of severe sepsis that target crude (total) mortality as an end point do not have sufficient power to detect differences in mortality due to the intervention. We aim to discuss the importance of including the subcomponents of crude mortality in study design; estimate how sample size requirements change based on the proportion of attributable mortality; and how minor changes from predicted outcomes can affect results. We derived statistical curves to illustrate our points.

Cigarette pack size and consumption: an adaptive randomised controlled trial

Background Observational evidence suggests that cigarette pack size – the number of cigarettes in a single pack – is associated with consumption but experimental evidence of a causal relationship is lacking. The tobacco industry is introducing increasingly large packs, in the absence of maximum cigarette pack size regulation. In Australia, the minimum pack size is 20 but packs of up to 50 cigarettes are available. We aimed to estimate the impact on smoking of reducing cigarette pack sizes from ≥25 to 20 cigarettes per pack. Method A two-stage adaptive parallel group RCT in which Australian smokers who usually purchase packs containing ≥25 cigarettes were randomised to use only packs containing either 20 (intervention) or their usual packs (control) for four weeks. The primary outcome, the average number of cigarettes smoked per day, was measured through collecting all finished cigarette packs, labelled with the number of cigarettes participants smoked. An interim sample size re-estimation was used to evaluate the possibility of detecting a meaningful difference in the primary outcome. Results The interim analysis, conducted when 124 participants had been randomised, suggested 1122 additional participants needed to be randomised for sufficient power to detect a meaningful effect. This exceeded pre-specified criteria for feasible recruitment, and data collection was terminated accordingly. Analysis of complete data (n = 79) indicated that the mean cigarettes smoked per day was 15.9 (SD = 8.5) in the intervention arm and 16.8 (SD = 6.7) among controls (difference − 0.9: 95%CI = − 4.3, 2.6). Conclusion It remains unclear whether reducing cigarette pack sizes from ≥25 to 20 cigarettes reduces cigarette consumption. Importantly, the results of this study provide no evidence that capping cigarette pack sizes would be ineffective at reducing smoking. The limitations identified in this study can inform a more efficient RCT, which is urgently required to address the dearth of experimental evidence on the impact of large cigarette pack sizes on smoking. Trial registration 10.1186/ISRCTN34202533