Entropy estimates of small data sets

Estimating entropies from limited data series is known to be a non-trivial task. Naive estimations are plagued with both systematic (bias) and statistical errors. Here, we present a new 'balanced estimator' for entropy functionals Shannon, R\'enyi and Tsallis) specially devised to provide a compromise between low bias and small statistical errors, for short data series. This new estimator out-performs other currently available ones when the data sets are small and the probabilities of the possible outputs of the random variable are not close to zero. Otherwise, other well-known estimators remain a better choice. The potential range of applicability of this estimator is quite broad specially for biological and digital data series.Comment: 11 pages, 2 figure

Performance Analysis and Functional Verification of the Stop-and-Wait Protocol in HOL

Real-time systems usually involve a subtle interaction of a number of distributed components and have a high degree of parallelism, which makes their performance analysis quite complex. Thus, traditional techniques, such as simulation, or the state-based formal methods usually fail to produce reasonable results. In this paper, we propose to use higher-order-logic (HOL) theorem proving for the performance analysis of real-time systems. The idea is to formalize the real-time system as a logical conjunction of HOL predicates, whereas each one of these predicates define an autonomous component or process of the given real-time system. The random or unpredictable behavior found in these components is modeled as random variables. This formal specification can then be used in a HOL theorem prover to reason about both functional and performance related properties of the given real-time system. In order to illustrate the practical effectiveness of our approach, we present the analysis of the Stop-and-Wait protocol, which is a classical example of real-time systems. The functional correctness of the protocol is verified by proving that the protocol ensures reliable data transfers. Whereas, the average message delay relation is verified in HOL for the sake of performance analysis. The paper includes the protocol’s formalization details along with the HOL proof sketches for the major theorems

Priorities for Cardiovascular Outcomes Research: A Report of the National Heart, Lung, and Blood Institute\u27s Centers for Cardiovascular Outcomes Research Working Group

The Centers for Cardiovascular Outcomes Research (CCORs) held a meeting to review how cardiovascular outcomes research had evolved in the decade since the National Heart, Lung, and Blood Institute 2004 working group report and to consider future directions. The conference involved representatives from governmental agencies, outcomes research thought leaders, and public and private healthcare partners. The main purposes of this meeting were to (1) advance collaborative high-yield, high-impact outcomes research; (2) identify priorities and barriers to important cardiovascular outcomes research; and (3) define future needs for the field. This report highlights the key topics covered during the meeting, including an examination of the recent history of outcomes research, an evaluation of the current academic climate, and a vision for the future of cardiovascular outcomes research

An international focus on cardiac surgery nursing : an introduction

In the ‘International Year of the Nurse and Midwife’, the focus is on celebrating the role of the nurse and highlighting the global burden of disease, as well as how nursing can be influential in strengthening universal health coverage. As cardiac surgery is considered the ‘unborn child of global surgery’, the aim of this six-paper series is to draw together these two important themes: to celebrate the role of nursing in advancing care in cardiac surgery and to provide an international perspective of cardiac surgery nursing

Training cardiovascular outcomes researchers: A survey of mentees and mentors to identify critical training gaps and needs

BACKGROUND: Many young investigators are interested in cardiovascular (CV) outcomes research; however, the current training experience of early investigators across the United States is uncertain. METHODS: From April to November 2014, we surveyed mentees and mentors of early-stage CV outcomes investigators across the United States. We contacted successful grantees of government agencies, members of professional organizations, and trainees in CV outcomes training programs. RESULTS: A total of 185 (of 662) mentees and 76 (of 541) mentors completed the survey. Mentees were equally split by sex; most had completed training \u3e 3 years before completing the survey and were clinicians. Mentors were more likely women, mostly \u3e /=20 years posttraining, and at an associate/full professor rank. Mentors reported devoting more time currently to clinical work than when they were early in their career and mentoring 2-4 people simultaneously. More than 80% of mentees started training to become academicians and completed training with the same goal. More than 70% of mentees desired at least 50% research time in future jobs. More than 80% of mentors believed that future investigators would need more than 50% time dedicated to research. Most mentees (80%) were satisfied with their relationship with their mentor and reported having had opportunities to develop independently. Mentors more frequently than mentees reported that funding cutbacks had negatively affected mentees\u27 ability to succeed (84% vs 58%). Across funding mechanisms, mentees were more optimistic than mentors about securing funding. Both mentees and mentors reported greatest preparedness for job/career satisfaction (79% for both) and publications (84% vs 92%) and least preparedness for future financial stability (48% vs 46%) and work-life balance (47% vs 42%). CONCLUSIONS: Survey findings may stimulate future discourse and research on how best to attract, train, and retain young investigators in CV outcomes research. Insights may help improve existing training programs and inform the design of new ones