Multi-robot task allocation for safe planning under dynamic uncertainties

This paper considers the problem of multi-robot safe mission planning in uncertain dynamic environments. This problem arises in several applications including safety-critical exploration, surveillance, and emergency rescue missions. Computation of a multi-robot optimal control policy is challenging not only because of the complexity of incorporating dynamic uncertainties while planning, but also because of the exponential growth in problem size as a function of the number of robots. Leveraging recent works obtaining a tractable safety maximizing plan for a single robot, we propose a scalable two-stage framework to solve the problem at hand. Specifically, the problem is split into a low-level single-agent planning problem and a high-level task allocation problem. The low-level problem uses an efficient approximation of stochastic reachability for a Markov decision process to handle the dynamic uncertainty. The task allocation, on the other hand, is solved using polynomial-time forward and reverse greedy heuristics. The safety objective of our multi-robot safe planning problem allows an implementation of the greedy heuristics through a distributed auction-based approach. Moreover, by leveraging the properties of the safety objective function, we ensure provable performance bounds on the safety of the approximate solutions proposed by these two heuristics. Our result is illustrated through case studies

The Search for Smart Schools: Identifying Texas School Districts’ Best Practices

This report outlines findings from the TXSmartSchools.org (TSS) Capstone Team’s mixed methodology study identifying best practices in high performing and cost-efficient school districts. TSS was particularly interested in finding best practices transferable from high performing school districts to low performing districts. The Capstone Team accomplished this using the TSS concept of “fiscal peers.” After completing a narrative literature review on the best practices in public education, the Capstone Team examined the effect of various school district expenditures on academic performance and cost efficiency through quantitative methods. The Capstone Team’s findings suggest the amount of money invested in practices are not indicative of the quality of the programs. Additional findings demonstrate the administrative cost ratio caps do not improve cost efficiency, and investments in bilingual education are associated with improved academic performance. To better describe the practices employed in school districts, semistructured interviews were conducted with school district officials. The findings from interviews with chief business officers and superintendents capture the importance of culture in district practices and operations. Based on the quantitative and qualitative findings, the Capstone Team makes recommendations that can be implemented at the district and state level. Further research is needed that will allow educators and researchers to better identify the best practices that will improve Texas schools’ and districts’ student academic achievement and fiscal efficiency

Conceptualizing and measuring distance in international business research:Recurring questions and best practice guidelines

Distance is a central concept in international business research, yet there is debate about the construct as well as its operationalization. In this editorial, we address three of the most important recurring questions posed by authors, editors, and reviewers by examining the theory, methods, and data of distance research. We discuss (1) how to theorize on distance, and (2) what method and (3) what data to use when constructing a distance index. We develop practical recommendations grounded in theory, illustrating and supporting them by calculating cross-country distance indices for all available country pairs and two of the most used distance indices: cultural and institutional. We show that, whereas a specific method to calculate distance may matter to some extent, the choice for a specific cultural or institutional framework to measure cultural or institutional distance has a major impact on country-pair distances. Overall, this editorial highlights the importance of matching data and method to the theoretical argument.</p

A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction

Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease

The Search for Smart Schools: Identifying Texas School Districts’ Best Practices

This report outlines findings from the TXSmartSchools.org (TSS) Capstone Team’s mixed methodology study identifying best practices in high performing and cost-efficient school districts. TSS was particularly interested in finding best practices transferable from high performing school districts to low performing districts. The Capstone Team accomplished this using the TSS concept of “fiscal peers.” After completing a narrative literature review on the best practices in public education, the Capstone Team examined the effect of various school district expenditures on academic performance and cost efficiency through quantitative methods. The Capstone Team’s findings suggest the amount of money invested in practices are not indicative of the quality of the programs. Additional findings demonstrate the administrative cost ratio caps do not improve cost efficiency, and investments in bilingual education are associated with improved academic performance. To better describe the practices employed in school districts, semistructured interviews were conducted with school district officials. The findings from interviews with chief business officers and superintendents capture the importance of culture in district practices and operations. Based on the quantitative and qualitative findings, the Capstone Team makes recommendations that can be implemented at the district and state level. Further research is needed that will allow educators and researchers to better identify the best practices that will improve Texas schools’ and districts’ student academic achievement and fiscal efficiency

Adult Respiratory Syncytial Virus Infection and Hypoxic Cardiac Arrest—Coexistent or Causal? A Hypothesis-Generating Case Report

Respiratory syncytial virus (RSV) is a well-known pathogen in paediatric patients. However, it also causes substantial morbidity and mortality in adults, posing a major healthcare problem. We present a patient with chronic pulmonary conditions and an acute RSV infection, thus leading to cardiac arrest (CA). We speculate that RSV as the causative agent for CA should be considered in post-resuscitation care. From a wider public health perspective, immuno-naivety for RSV caused by the coronavirus disease 2019 pandemic may induce a severe rise in cases, morbidity, and mortality in the future

Hemodynamic and Rhythmologic Effects of Push-Dose Landiolol in Critical Care&mdash;A Retrospective Cross-Sectional Study

Background: The highly &beta;1-selective beta-blocker Landiolol is known to facilitate efficient and safe rate control in non-compensatory tachycardia or dysrhythmia when administered continuously. However, efficacy and safety data of the also-available bolus formulation in critically ill patients are scarce. Methods: We conducted a retrospective cross-sectional study on a real-life cohort of critical care patients, who had been treated with push-dose Landiolol due to sudden-onset non-compensatory supraventricular tachycardia. Continuous hemodynamic data had been acquired via invasive blood pressure monitoring. Results: Thirty patients and 49 bolus applications were analyzed. Successful heart rate control was accomplished in 20 (41%) cases, rhythm control was achieved in 13 (27%) episodes, and 16 (33%) applications showed no effect. Overall, the heart rate was significantly lower (145 (130&ndash;150) vs. 105 (100&ndash;125) bpm, p &lt; 0.001) in a 90 min post-application observational period in all subgroups. The median changes in blood pressure after the bolus application did not reach clinical significance. Compared with the ventilation settings before the bolus application, the respiratory settings including the required FiO2 after the bolus application did not differ significantly. No serious adverse events were seen. Conclusions: Push-dose Landiolol was safe and effective in critically ill ICU patients. No clinically relevant impact on blood pressure was noted