Algorithms for Stable Matching and Clustering in a Grid

We study a discrete version of a geometric stable marriage problem originally proposed in a continuous setting by Hoffman, Holroyd, and Peres, in which points in the plane are stably matched to cluster centers, as prioritized by their distances, so that each cluster center is apportioned a set of points of equal area. We show that, for a discretization of the problem to an $n\times n$ grid of pixels with $k$ centers, the problem can be solved in time $O(n^2 \log^5 n)$, and we experiment with two slower but more practical algorithms and a hybrid method that switches from one of these algorithms to the other to gain greater efficiency than either algorithm alone. We also show how to combine geometric stable matchings with a $k$-means clustering algorithm, so as to provide a geometric political-districting algorithm that views distance in economic terms, and we experiment with weighted versions of stable $k$-means in order to improve the connectivity of the resulting clusters.Comment: 23 pages, 12 figures. To appear (without the appendices) at the 18th International Workshop on Combinatorial Image Analysis, June 19-21, 2017, Plovdiv, Bulgari

Strategies to Combat Opioid Use in Rural Communities

Webinar presentation discussing Opioid use across rural settings Drivers of rural opioid use Burden of opioid use in rural communities Evidence-based prevention, treatment, and recovery strategies to address rural opioid us

Rural America: A look beyond the images

The issues faced by patients and providers in rural health care differ greatly from those of urban counterparts. They also differ across rural communities. Understanding these differences, and the differences among rural populations across America, is critical to providing health services to rural Americans, who are often impeded by economic factors, cultural and social differences, educational shortcomings and isolation in their efforts to lead normal, healthy lives. The challenges provide opportunities for Catholic health care to make a difference in the lives and health of some of the nation\u27s most vulnerable citizens

Prevention of Drug Use and Treatment of Drug Use Disorders in Rural Settings

This Guide on Prevention of Drug Use and Treatment of Drug Use Disorders in Rural Settings was prepared by the United Nations Office on Drugs and Crime (UNODC) Drug Prevention and Health Branch (DHB), in the context of the global project Treatnet II: OFID-UNODC Programme to prevent HIV/AIDS through Treatnet Phase II, with the aim of providing an awareness-raising tool and guidance for policymakers, public health officials, local authorities and other stakeholders in dealing with substance use issues in rural settings in their respective countries. This Guide will serve as an awareness-raising tool and guidance for policymakers, public health officials, local authorities and other stakeholders in dealing with substance use issues in rural settings in their respective countries. It will “set the stage” for the identification, assessment, planning and implementation of both prevention interventions and policies, as well as interventions targeting rural drug users, by: Describing substance use problems in rural settings and factors contributing to them. Identifying tools that can be used to assess the scope of rural substance use in their countries. Describing evidence-based prevention, treatment and recovery strategies that can be implemented in rural areas. Providing examples of successful promising and evidence-based strategies implemented in diverse rural areas worldwide. This Guide is intended to be shared widely with policymakers and other stakeholders concerned with the problems of substance use in rural settings. It provides an understanding of several key economic and social disparities driving rural substance use and the barriers to treatment experienced by rural people with substance use disorders

The Role of Rural Hospitals in Addressing Opioid and Other Substance Use Problems

Webinar presentation to the Small Rural Hospital Transition project addressing issues of rural opioid and other substance use issues, focusing on the role of rural hospitals, and the importance of community engagement. Component parts of an effective opioid/substance use system of care include prevention, treatment, and recovery. Models must be adapted to the geographic, resource, and cultural realities of rural areas. Examples of strategies are provided

On the Core of Dynamic Cooperative Games

We consider dynamic cooperative games, where the worth of coalitions varies over time according to the history of allocations. When defining the core of a dynamic game, we allow the possibility for coalitions to deviate at any time and thereby to give rise to a new environment. A coalition that considers a deviation needs to take the consequences into account because from the deviation point on, the game is no longer played with the original set of players. The deviating coalition becomes the new grand coalition which, in turn, induces a new dynamic game. The stage games of the new dynamical game depend on all previous allocation including those that have materialized from the deviating time on. We define three types of core solutions: fair core, stable core and credible core. We characterize the first two in case where the instantaneous game depends on the last allocation (rather than on the whole history of allocations) and the third in the general case. The analysis and the results resembles to a great extent the theory of non-cooperative dynamic games.Comment: 25 page

Excess mortality and guideline-indicated care following non-ST-elevation myocardial infarction

BACKGROUND: Adherence to guideline-indicated care for the treatment of non-ST-elevation myocardial infarction (NSTEMI) is associated with improved outcomes. We investigated the extent and consequences of non-adherence to guideline-indicated care across a national health system. METHODS: A cohort study (ClinicalTrials.gov identifier: NCT02436187) was conducted using data from the Myocardial Ischaemia National Audit Project (n = 389,057 NSTEMI, n = 247 hospitals, England and Wales, 2003-2013). Accelerated failure time models were used to quantify the impact of non-adherence on survival according to dates of guideline publication. RESULTS: Over a period of 1,079,044 person-years (median 2.2 years of follow-up), 113,586 (29.2%) NSTEMI patients died. Of those eligible to receive care, 337,881 (86.9%) did not receive one or more guideline-indicated intervention; the most frequently missed were dietary advice (n = 254,869, 68.1%), smoking cessation advice (n = 245,357, 87.9%), P2Y12 inhibitors (n = 192,906, 66.3%) and coronary angiography (n = 161,853, 43.4%). Missed interventions with the strongest impact on reduced survival were coronary angiography (time ratio: 0.18, 95% confidence interval (CI): 0.17-0.18), cardiac rehabilitation (time ratio: 0.49, 95% CI: 0.48-0.50), smoking cessation advice (time ratio: 0.53, 95% CI: 0.51-0.57) and statins (time ratio: 0.56, 95% CI: 0.55-0.58). If all eligible patients in the study had received optimal care at the time of guideline publication, then 32,765 (28.9%) deaths (95% CI: 30,531-33,509) may have been prevented. CONCLUSION: The majority of patients hospitalised with NSTEMI missed at least one guideline-indicated intervention for which they were eligible. This was significantly associated with excess mortality. Greater attention to the provision of guideline-indicated care for the management of NSTEMI will reduce premature cardiovascular deaths

Using small molecules to facilitate exchange of bicarbonate and chloride anions across liposomal membranes

Bicarbonate is involved in a wide range of biological processes, which include respiration, regulation of intracellular pH and fertilization. In this study we use a combination of NMR spectroscopy and ion-selective electrode techniques to show that the natural product prodigiosin, a tripyrrolic molecule produced by microorganisms such as Streptomyces and Serratia, facilitates chloride/bicarbonate exchange (antiport) across liposomal membranes. Higher concentrations of simple synthetic molecules based on a 4,6-dihydroxyisophthalamide core are also shown to facilitate this antiport process. Although it is well known that proteins regulate Cl-/HCO3- exchange in cells, these results suggest that small molecules may also be able to regulate the concentration of these anions in biological systems