Applying an abstract data structure description approach to parallelizing scientific pointer programs

Even though impressive progress has been made in the area of parallelizing scientific programs with arrays, the application of similar techniques to programs with pointer data structures has remained difficult. Unlike arrays which have a small number of well-defined properties that can be utilized by a parallelizing compiler, pointer data structures are used to implement a wide variety of structures that exhibit a much more diverse set of properties. The complexity and diversity of such properties means that, in general, scientific programs with pointer data structures cannot be effectively analyzed by an optimizing and parallelizing compiler.In order to provide a system in which the compiler can fully utilize the properties of different types of pointer data structures, we have developed a mechanism for the Abstract Description of Data Structures (ADDS). With our approach, the programmer can explicitly describe important properties such as dimensionality of the pointer data structure, independence of dimensions, and direction of traversal. These abstract descriptions of pointer data structures are then used by the compiler to guide analysis, optimization, and parallelization.In this paper we summarize the ADDS approach through the use of numerous examples of data structures used in scientific computations, we illustrate how such declarations are natural and non-tedious to specify, and we show how the ADDS declarations can be used to improve compile-time analysis. In order to demonstrate the viability of our approach, we show how such techniques can be used to parallelize an important class of scientific codes which naturally use recursive pointer data structures. In particular, we use our approach to develop the parallelization of an N-body simulation that is based on a relatively complicated pointer data structure, and we report the speedup results for a Sequent multiprocessor

Genet: A Quickly Scalable Fat-Tree Overlay for Personal Volunteer Computing using WebRTC

WebRTC enables browsers to exchange data directly but the number of possible concurrent connections to a single source is limited. We overcome the limitation by organizing participants in a fat-tree overlay: when the maximum number of connections of a tree node is reached, the new participants connect to the node's children. Our design quickly scales when a large number of participants join in a short amount of time, by relying on a novel scheme that only requires local information to route connection messages: the destination is derived from the hash value of the combined identifiers of the message's source and of the node that is holding the message. The scheme provides deterministic routing of a sequence of connection messages from a single source and probabilistic balancing of newer connections among the leaves. We show that this design puts at least 83% of nodes at the same depth as a deterministic algorithm, can connect a thousand browser windows in 21-55 seconds in a local network, and can be deployed for volunteer computing to tap into 320 cores in less than 30 seconds on a local network to increase the total throughput on the Collatz application by two orders of magnitude compared to a single core

Demand and Reimbursement Effects of Healthcare Reform: Health Care Utilization and Infant Mortality in Thailand

The Thai 30 Baht program was one of the largest health system reforms ever undertaken by a low-middle income country. In addition to lowering the cost of care for the previously uninsured in public facilities, it also entailed a fourfold increase in funding provided to hospitals to care for the poorest 30% of the population (who were already publicly insured). For the previously uninsured, we find that the 30 Baht program led to increased health care utilization, as well as a shift from private to public sources of care. But, we find a larger increase for the poor who were previously publicly insured, especially amongst infants and women of childbearing age. Using vital statistics records, we find that the increased access to healthcare by the publicly insured poor led to a reduction in their infant mortality of at least 6.5 per 1,000 births. This suggests significant improvements in infant mortality rates can be achieved through increased access to healthcare services for the poor and marginalized groups.

A review of the differences between normal and osteoarthritis articular cartilage in human knee and ankle joints

Background: Osteoarthritis (OA) is the most common joint disease yet its pathophysiology is still poorly understood. It is more prevalent in some lower limb joints than others; in particular the knee is more commonly affected than the ankle. Research into articular cartilage and OA has primarily focussed on using animal models. However, it is apparent that articular cartilage differs between species, so more research is concentrating on human cartilage. Objective: This paper reviews recent studies that have been undertaken to elucidate the reasons for this, and to discover if the findings would alter the conception that articular cartilage is not capable of repair. Method: Primary research papers into human knee and ankle cartilage published since 1997 have been reviewed. Results: Differences in the structure, metabolism, physical properties and response to trauma have been found, implying that ankle cartilage may be more resistant to damage. Conclusions: More research is needed before definitive conclusions can be reached, but the findings so far suggest that OA should not be accepted as the inevitable outcome of joint injury and individuals and practitioners, such as podiatrists, may be able to use simple measures to prevent or delay its onse

The Soul in Trama: Poetry of War in the Classroom

Reflecting on a dark side of human experience, this article explains how one teacher used poetry to invite students into a deeper reflection on life, death, and justice. With startling and painful examples from modern poetry, the author helps us to appreciate anew the tremendous power of the word

Emergency Departments and STEMI Care, Are the Guidelines Being Followed?

The purpose of this study examined if an Emergency Department (ED) in a small rural hospital in western North Carolina is compliant with the American College of Cardiology (ACC) and the American Heart Association (AHA) guidelines for obtaining Electrocardiogram\u27s (ECG\u27s), administering fibrinolytics, and performing Primary Percutaneous Coronary Intervention (PCI) on patients with chest pain diagnosed with ST-Elevation Myocardial Infarction (STEMI). The national standards for ECGs is less than 10 minutes from arrival to first medical contact (FMC) with triage nurse; for fibrinolytics, less than 30 minutes from arrival to FMC; and for FMC to PCI, less than 90 minutes. The national standard for ECG times is for all patients presenting to the ED with symptom of chest pain. The national standards for FMC to PCI and fibrinolytics are for STEMI patients only. Using a retrospective design, twenty-five patient records were examined from January 2010 to December 2011. The one-sample t test was used to compare the sample means for the ECG and FMC to PCI times to the national standards. The one sample t test revealed a significant difference in length of time between arrival to the ED and ECG between the sample and national standard. The length of time between arrival and ECG for the sample was significantly shorter that the national standard of 10 minutes or less. The length of time between FMC and PCI, although significantly different, was significantly longer than the national standard of 90 minutes. There was insufficient data to examine the length of time for the administration of fibrinolytics. Additional research is needed using a larger sample size as well as additional EDs that transfer patients for PCI