Pure Ionic Electrospray Thruster Control Electronics Architecture and Performance

Propulsion has been identified as a critical capability for future SmallSat and CubeSat missions. Due to strict volume constraints imposed by these small platforms, efficient means of propulsion is key to enabling sophisticated missions with large payload mass fraction and ΔV

Exploration and Coverage with Swarms of Settling Agents

We consider several algorithms for exploring and filling an unknown, connected region, by simple, airborne agents. The agents are assumed to be identical, autonomous, anonymous and to have a finite amount of memory. The region is modeled as a connected sub-set of a regular grid composed of square cells. The algorithms described herein are suited for Micro Air Vehicles (MAV) since these air vehicles enable unobstructed views of the ground below and can move freely in space at various heights. The agents explore the region by applying various action-rules based on locally acquired information Some of them may settle in unoccupied cells as the exploration progresses. Settled agents become virtual pheromones for the exploration and coverage process, beacons that subsequently aid the remaining, and still exploring, mobile agents. We introduce a backward propagating information diffusion process as a way to implement a deterministic indicator of process termination and guide the mobile agents. For the proposed algorithms, complete covering of the graph in finite time is guaranteed when the size of the region is fixed. Bounds on the coverage times are also derived. Extensive simulation results exhibit good agreement with the theoretical predictions

Defining localities of inadequate treatment for childhood asthma: A GIS approach

BACKGROUND: The use of Geographic Information Systems (GIS) has great potential for the management of chronic disease and the analysis of clinical and administrative health care data. Asthma is a chronic disease associated with substantial morbidity, mortality, and health care use. Epidemiologic data from all over the world show an increasing prevalence of asthma morbidity and mortality despite the availability of effective treatment. These facts led to the emergence of strategies developed to improve the quality of asthma care. THE OBJECTIVE: To develop an efficient tool for quality assurance and chronic disease management using a Geographic Information System (GIS). GEOGRAPHIC LOCATION: The southern region of Israel. January 1998 – October 2000. DATABASES: Administrative claims data of the largest HMO in Israel: drug dispensing registry, demographic data, Emergency Room visits, and hospitalization data bases. METHODS: We created a list of six markers for inadequate pharmaceutical treatment of childhood asthma from the Israeli clinical guidelines. We used this list to search the drug dispensing registry to identify asthmatic children who received inadequate treatment and to assess their health care utilization and bad outcomes: emergency room visits and hospitalizations. Using GIS we created thematic maps on which we located the clinics with a high percentage of children for whom the treatment provided was not in adherence with the clinical guidelines. RESULTS: 81% of the children were found to have at least one marker for inadequate treatment; 17.5% were found to have more than one marker. Children with markers were found to have statistically significant higher rates of Emergency Room visits, hospitalizations and longer length of stay in hospital compared with children without markers. The maps show in a robust way which clinics provided treatment not in accord with the clinical guidelines. Those clinics have high rates of Emergency Room visits, hospitalizations and length of stay. CONCLUSION: Integration of clinical guidelines, administrative data and GIS can create an efficient interface between administrative and clinical information. This tool can be used for allocating sites for quality assurance interventions

A bricolage-style exploratory scenario analysis to manage uncertainty in socio-environmental systems modeling: investigating integrated water management options

Exploratory analysis, while useful in assessing the implications of model assumptions under large uncertainty, is considered at best a semi-structured activity. There is no algorithmic way for performing exploratory analysis and the existing canonical techniques have their own limitations. To overcome this, we advocate a bricolage-style exploratory scenario analysis, which can be crafted by pragmatically and strategically combining different methods and practices. Our argument is illustrated using a case study in integrated water management in the Murray-Darling Basin, Australia. Scenario ensembles are generated to investigate potential policy innovations, climate and crop market conditions, as well as the effects of uncertainties in model components and parameters. Visualizations, regression trees and marginal effect analyses are exploited to make sense of the ensemble of scenarios. The analysis includes identifying patterns within a scenario ensemble, by visualizing initial hypotheses that are informed by prior knowledge, as well as by visualizing new hypotheses based on identified influential variables. Context-specific relationships are explored by analyzing which values of drivers and management options influence outcomes. Synthesis is achieved by identifying context-specific solutions to consider as part of policy design. The process of analysis is cast as a process of finding patterns and formulating questions within the ensemble of scenarios that merit further examination, allowing end-users to make the decision as to what underlying assumptions should be accepted, and whether uncertainties have been sufficiently explored. This approach is especially advantageous when the precise intentions of management are still subject to deliberations. By describing the reasoning and steps behind a bricolage-style exploratory analysis, we hope to raise awareness of the value of sharing this kind of (common but not often documented) analysis process, and motivate further work to improve sharing of know-how about bricolage in practice.This work was funded by the Australian National Centre for Groundwater Research and Training (NCGRT), and the MDBA-NCGRT Partnership. Joseph Guillaume was supported by the Academy of Finland WASCO water scarcity atlas project (grant number 305471

Diagnosing Crohn\u27s Disease: An economic analysis comparing wireless capsule endoscopy with traditional diagnostic procedures

The purpose of this study was to review economic considerations related to establishing a diagnosis of Crohn\u27s disease, and to compare the costs of a diagnostic algorithm incorporating wireless capsule endoscopy (WCE) with the current algorithm for diagnosing Crohn\u27s disease suspected in the small bowel. Published literature, clinical trial data on WCE in comparison to other diagnostic tools, and input from clinical experts were used as data sources for (1) identifying contributors to the costs of diagnosing Crohn\u27s disease; (2) exploring where WCE should be placed within the diagnostic algorithm for Crohn\u27s; and (3) constructing decision tree models with sensitivity analyses to explore costs (from a payor perspective) of diagnosing Crohn\u27s disease using WCE compared to other diagnostic methods. Literature review confirms that Crohn\u27s disease is a significant and growing public health concern from clinical, humanistic and economic perspectives, and results in a long-term burden for patients, their families, providers, insurers, and employers. Common diagnostic procedures include radiologic studies such as small bowel follow through (SBFT), enteroclysis, CT scans, ultrasounds, and MRIs, as well as serologic testing, and various forms of endoscopy. Diagnostic costs for Crohn\u27s disease can be considerable, especially given the cycle of repeat testing due to the low diagnostic yield of certain procedures and the inability of current diagnostic procedures to image the entire small bowel. WCE has a higher average diagnostic yield than comparative procedures due to imaging clarity and the ability to visualize the entire small bowel. Literature review found the average diagnostic yield of SBFT and colonoscopy for work-up of Crohn\u27s disease to be 53.87%, whereas WCE had a diagnostic yield of 69.59%. A simple decision tree model comparing two arms--colonoscopy and SBFT, or WCE--estimates that WCE produces a cost savings of 291dollars for each case presenting for diagnostic work-up for Crohn\u27s. Sensitivity analysis varying diagnostic yields of colonoscopy and SBFT vs. WCE demonstrates that WCE is still less costly than SBFT and colonoscopy even at their highest reported yields, as long as the diagnostic yield of WCE is 64.10% or better. Employing WCE as a first-line diagnostic procedure appears to be less costly, from a payor perspective, than current common procedures for diagnosing suspected Crohn\u27s disease in the small bowel. Although not addressed in this model, earlier diagnosis with WCE (due to higher diagnostic yield) also could lead to earlier management, improved quality of life and workplace productivity for people with Crohn\u27s disease

A step in understanding the Hubble tension

As cosmological data have improved, tensions have arisen. One such tension is the difference between the locally measured Hubble constant H 0 and the value inferred from the cosmic microwave background (CMB). Interacting radiation has been suggested as a solution, but studies show that conventional models are precluded by high- ℓ CMB polarization data. It seems at least plausible that a solution may be provided by related models that distinguish between high- and low- ℓ multipoles. When interactions of strongly-coupled radiation are mediated by a force carrier that becomes nonrelativistic, the dark radiation undergoes a “step” in which its relative energy density increases as the mediator deposits its entropy into the lighter species. If this transition occurs while CMB-observable modes are inside the horizon, high- and low- ℓ peaks are impacted differently, corresponding to modes that enter the horizon before or after the step. These dynamics are naturally packaged into the simplest supersymmetric theory, the Wess-Zumino model, with the mass of the scalar mediator near the eV scale. We investigate the cosmological signatures of such Wess-Zumino dark radiation (WZDR) and find that it provides an improved fit to the CMB alone, favoring larger values of H 0 . If supernovae measurements from the SH0ES Collaboration are also included in the analysis, the inferred value of H 0 is yet larger, but the preference for dark radiation and the location of the transition is left nearly unchanged. Utilizing a standardized set of measures, we compare to other models and find that WZDR is among the most successful at addressing the H 0 tension and is the best of those with a Lagrangian formulation.https://arxiv.org/pdf/2111.00014Accepted manuscrip