A practical, unitary simulator for non-Markovian complex processes

Stochastic processes are as ubiquitous throughout the quantitative sciences as they are notorious for being difficult to simulate and predict. In this letter we propose a unitary quantum simulator for discrete-time stochastic processes which requires less internal memory than any classical analogue throughout the simulation. The simulator's internal memory requirements equal those of the best previous quantum models. However, in contrast to previous models it only requires a (small) finite-dimensional Hilbert space. Moreover, since the simulator operates unitarily throughout, it avoids any unnecessary information loss. We provide a stepwise construction for simulators for a large class of stochastic processes hence directly opening the possibility for experimental implementations with current platforms for quantum computation. The results are illustrated for an example process.Comment: 12 pages, 5 figure

The relevance of a rules-based maize marketing policy : an experimental case study of Zambia

Strategic interaction between public and private actors is increasingly recognized as an important determinant of agricultural market performance in Africa and elsewhere. Trust and consultation tend to positively affect private activity while uncertainty of government behavior impedes it. This paper reports on a laboratory experiment based on a stylized model of the Zambian maize market. The experiment facilitates a comparison between discretionary interventionism and a rules-based policy in which the government pre-commits itself to a future course of action. A simple precommitment rule can, in theory, overcome the prevailing strategic dilemma by encouraging private sector participation. Although this result is also borne out in the economic experiment, the improvement in private sector activity is surprisingly small and not statistically significant due to irrationally cautious choices by experimental governments. Encouragingly, a rules-based policy promotes a much more stable market outcome, thereby substantially reducing the risk of severe food shortages. These results underscore the importance of predictable and transparent rules for the state's involvement in agricultural markets.Markets and Market Access,Food&Beverage Industry,Public Sector Corruption&Anticorruption Measures,Food Security,Access to Markets

QTC is Associated with Obesity and Physical Activity Level for African American Females

Long QT syndrome (LQTS) is an independent risk factor for cardiovascular or ischemic disease mortality. Obesity as a cause for acquired LQTS in otherwise healthy individuals is rapidly gaining the attention of the scientific community. African American people have a higher incidence of obesity compared to Caucasians, yet race-specific information is not available for their prevalence of LQTS. Chronic physical activity can help reduce the incidence of obesity, yet little is known about the effects of chronic physical activity on acquired LQTS. Subjects in this study were a volunteer sample of African American mothers (21-53 yr, n = 44) and daughters (5-17 yr, n = 66) recruited from the inner city Dayton, Ohio community using posters placed in a local agency that provides assistance for mothers with children. Electrocardiograph (ECG) tracings were drawn, and body weight and height were measured without shoes. Body mass index (BMI) was calculated (weight in kilograms divided by height in meters squared). Each subject completed an interviewer administered physical activity questionnaire. QTc (QT interval corrected for heart rate) data were grouped according to subject body mass index (BMI) for normal weight (BMI \u3c 25), overweight (BMI 25 -29.99), and obesity (BMI\u3e30) and statistically analyzed using an ANOVA test to determine if QTc duration was significantly different between BMI groups. Correlation tests were run between physical activity level and QTc, and between mothers\u27 and daughters\u27 QTc. Results indicated a longer QTc for obese mothers and daughters compared to normal-weight mothers and daughters (p = 0.003). Self-reported PA was inversely associated with QTc for mothers and daughters, but reached statistical significance (r = -0.46; p \u3c 0.001) for the obese daughters only. Mother and daughter QTc durations were significantly and positively correlated (r = 0.42; p \u3c 0.0001). These results indicate a positive association between obesity and QTc and an inverse association between PA and QTc

Technology Paved the Road for Students in a High-School Dropout Recovery Program to an Online College Class

Although there are Federal programs that are intended to assist a wide range of people with getting a college education, the educational attainment statistics confirm that these programs are not reaching the students who are the least apt to go to college. This chapter describes how technology enabled 52 inner-city high school students, 49% of whom had cumulative high school grade point averages (GPA) that were between 1.0 and 1.9 points, to be dually enrolled in an online college class and their online high school classes. The class average for the quizzes the students completed was 88% and the students who took the final exam scored, on average, 86%. There were some unexpected delays and difficulties along the way, but the students performed at a college level in a difficult class