OpenCL Actors - Adding Data Parallelism to Actor-based Programming with CAF

The actor model of computation has been designed for a seamless support of concurrency and distribution. However, it remains unspecific about data parallel program flows, while available processing power of modern many core hardware such as graphics processing units (GPUs) or coprocessors increases the relevance of data parallelism for general-purpose computation. In this work, we introduce OpenCL-enabled actors to the C++ Actor Framework (CAF). This offers a high level interface for accessing any OpenCL device without leaving the actor paradigm. The new type of actor is integrated into the runtime environment of CAF and gives rise to transparent message passing in distributed systems on heterogeneous hardware. Following the actor logic in CAF, OpenCL kernels can be composed while encapsulated in C++ actors, hence operate in a multi-stage fashion on data resident at the GPU. Developers are thus enabled to build complex data parallel programs from primitives without leaving the actor paradigm, nor sacrificing performance. Our evaluations on commodity GPUs, an Nvidia TESLA, and an Intel PHI reveal the expected linear scaling behavior when offloading larger workloads. For sub-second duties, the efficiency of offloading was found to largely differ between devices. Moreover, our findings indicate a negligible overhead over programming with the native OpenCL API.Comment: 28 page

A statin-regulated microRNA represses c-Myc expression and function.

c-Myc dysregulation is one of the most common abnormalities found in human cancer. MicroRNAs (miRNAs) are functionally intertwined with the c-Myc network as multiple miRNAs are regulated by c-Myc, while others directly suppress c-Myc expression. In this work, we identified miR-33b as a primate-specific negative regulator of c-Myc. The human miR-33b gene is located at 17pl1.2, a genomic locus frequently lost in medulloblastomas, which are pediatric brain tumors that display c-Myc overproduction. Through a small-scale screening with drugs approved by the US Food and Drug Administration (FDA), we found that lovastatin up-regulated miR-33b expression, reduced cell proliferation, and impaired c-Myc expression and function in miR-33b-positive medulloblastoma cells. In addition, a low dose of lovastatin treatment at a level comparable to approved human oral use reduced tumor growth in mice orthotopically xenografted with cells carrying miR-33b, but not with cells lacking miR-33b. This work presents a highly promising therapeutic option, using drug repurposing and a miRNA as a biomarker, against cancers that over-express c-Myc

Intentions to use contraceptives in Pakistan: implications for behavior change campaigns

<p>Abstract</p> <p>Background</p> <p>Since 1990-91, traditional method use has increased at a faster rate in Pakistan than modern method use. The importance of hormonal methods or the IUD has diminished and that of traditional methods has increased in the method mix. There is a need to identify factors motivating and deterring the adoption of specific family planning methods among married men and women in Pakistan.</p> <p>Methods</p> <p>In addition to social and demographic characteristics of respondents, a representative household survey collected information on psychological correlates of family planning behavior from 1,788 non-pregnant wives and 1,805 husbands with not-pregnant wives. Males and females were from separate households. Principal components analysis was conducted to identify the underlying constructs that were important for each gender. Multinomial logistic regression analysis was conducted to determine the correlates of male and female intentions to use contraceptive methods.</p> <p>Results</p> <p>Amongst women, the perception that her in-laws support family planning use was the strongest determinant of her intentions to use contraceptive methods. A woman's belief in the importance of spacing children and her perception that a choice of methods and facilities with competent staff were available were also powerful drivers of her intentions to use contraceptive methods. The strongest obstacle to a woman's forming an intention to use contraceptive methods was her belief that family planning decisions were made by the husband and fertility was determined by God's will. Fears that family planning would harm a woman's womb lowered a woman's intentions to use methods requiring procedures, such as the IUD and female sterilization.</p> <p>The perception that a responsible, caring, husband uses family planning to improve the standard of living of his family and to protect his wife's health was the most important determinant of a man's intention to use condoms. A husband's lack of self-efficacy in being able to discuss family planning with his wife was the strongest driver of the intention to use withdrawal. A man's fear that contraceptives would make a woman sterile and harm her womb lowered his intention to use modern contraceptive methods.</p> <p>Conclusions</p> <p>These findings highlight the importance of having secondary target audiences such as mothers-in-law and husbands in family planning behavior change campaigns implemented in Pakistan. Campaigns that stress the importance of child spacing are likely to have an impact. Client perceptions of the quality of care are important determinants of intentions to use contraceptive methods in Pakistan. Client concerns that the IUD and sterilization procedures might harm a woman's womb and cause sterility should be addressed. The findings suggest that there is a need to assess the actual quality of service delivery in Pakistan.</p

Declarative Scheduling for Active Objects

International audienceActive objects are programming constructs that abstract dis- tribution and help to handle concurrency. In this paper, we extend the multiactive object programming model to offer a priority specification mechanism. This mechanism allows programmers to have control on the scheduling of requests. The priority representation is based on a dependency graph which makes it very convenient to use. This article shows how to use this mechanism from the programmer side, and exposes the main properties of the dependency graph. The software architecture of our implementation is also presented, as it can be applied to various scheduling systems. Finally, we validate our approach through a microbenchmark that shows that the overhead of our priority representation is rather low. On the whole, we provide a general pattern to introduce a prioritized scheduling in active objects or in any other con- current systems. The resulting framework is shown to be fine-grained, user-friendly, and efficient

Vitamin D Status in Lean and Obese Mexican American Children

Vitamin D deficiency is a worldwide problem amongst adolescents and adults, particularly in minority populations due to high skin melanin content. Melanin blocks the absorption of UVB photons, which limits natural vitamin D accumulation, requiring more dietary intake of vitamin D. Vitamin D deficiency is associated with an increased risk for chronic diseases like cardiovascular disease and diabetes mellitus. Low levels of vitamin D are inversely correlated with systemic inflammation possibly mediating the relationship between vitamin D deficiency and disease. Adequate levels of vitamin D may decrease the risks of chronic diseases, including cardiovascular disease, diabetes mellitus, common cancers, and autoimmune diseases. Obesity is associated with an increased risk of vitamin D deficiency, because vitamin D can become sequestered deep in subcutaneous adipose tissue, where it is biologically inert. In the US, Mexican-Americans are at a higher risk for both obesity and obesity-associate chronic diseases, making them an ideal research population. Objective: Investigate the relationship between serum vitamin-D status and systemic inflammation in Mexican-American children of differing obesity status. Patients and Methods: Serum vitamin D concentration will be measured using a commercially available ELISA kit. Vitamin D status will be determined using norms established by the Institute of Medicine in 2010. Serum TNF-α, IL-6, and IL-8 concentration will be measured using a Luminex Multiplex assay (Millipore Milliplex)

A Silicon-Based Monolithic Optical Frequency Comb Source

Recently developed techniques for generating precisely equidistant optical frequencies over broad wavelength ranges are revolutionizing precision physical measurement [1-3]. These frequency "combs" are produced primarily using relatively large, ultrafast laser systems. However, recent research has shown that broad-bandwidth combs can be produced using highly-nonlinear interactions in microresonator optical parametric oscillators [4-11]. Such devices not only offer the potential for developing extremely compact optical atomic clocks but are also promising for astronomical spectroscopy [12-14], ultrashort pulse shaping [15], and ultrahigh-speed communications systems. Here we demonstrate the generation of broad-bandwidth optical frequency combs from a CMOS-compatible integrated microresonator [16,17], which is a fully-monolithic and sealed chip-scale device making it insensitive to the surrounding environment. We characterize the comb quality using a novel self-referencing method and verify that the comb line frequencies are equidistant over a bandwidth that is nearly an order of magnitude larger than previous measurements. In addition, we investigate the ultrafast temporal properties of the comb and demonstrate its potential to serve as a chip-scale source of ultrafast (sub-ps) pulses

Determination of Entropy and Specific Heat of Hydrogen from Partition Functions of Elementary Particles

Elementary particles are atomic or sub-atomic particles that make up all kinds of matter. They are classified into two main groups, namely: bosons and fermions. In other words, bosons and fermions are found in all states of matter, viz: solids, liquids and gases. Fermions are constituents of matter while bosons are force carriers. Bosons are particles that transmit interactions or the constituents of radiation. The main objective of this paper is to derive and integrate the intermolecular partition function into the general partition function of the elementary gases. The application of the partition function so formulated in the determination of the thermodynamic states of the elementary particles and its validity can eventually be addressed. The partition function of a system is the ratio of the total number of particles in the system to the number of particles in the lowest energy state of that system. Thus, it is dimensionless. Partition function is very important in the analyses of thermodynamic systems. Once an expression for the partition function of a system is known, then the thermodynamic functions appertaining to the system; entropy, specific heat capacity, Helmholtz free energy, internal energy, etc can be determined. Many have been neglecting the effects of intermolecular interactions while calculating the overall partition function of interacting systems. This article considered the common way of determining partition function, z without considering intermolecular interaction effects and compared it with z determined by taking cognizance of the effects of intermolecular interactions. A comparison of the two was made, and the result analyzed. An overview of the various z’s in the old way was presented and a new one called inter-particle interaction partition function was derived using the Schrodinger equation. . To validate the work, the entropies and specific heats of hydrogen were compared with published data by two-way ANOVA.  It was determined that the values were significantly different as expected. This work has established that intermolecular interactio

Small power tapping limit on dc-link of VSC HVDC transmission system

Abstract Power tapping from HVDC transmission corridor to serve rural areas has been the focus of many researchers and network planners. The tapping stations are to be of small power ratings so that it will not interfere with the main control and stability of the HVDC network. Several research works have assumed tap-off of different percentages of the main HVDC terminal rating without justification. This paper therefore proposes a simple analytical technique used to determine power tapping limit on DC-link of a VSC HVDC network. Effect of power tapping below and above the analytical tap limit is illustrated by results from simulation carried out in Matlab/Simulink, hence validating the proposed technique

Corticosterone Levels in Sedentary, Wheel, and Treadmill Acclimated Mice following a Bout of Forced Treadmill Running

Murine models have been used to study the immune response to exercise under various diet and training interventions .Our laboratory has previously studied the effect of forced exercise versus voluntary exercise on fasting blood glucose measurements. However, forced exercise may result in increased corticosterone levels. This may affect glucose levels and subsequent weight gain. Male, wild-type CD-1 mice were randomly divided into the following groups: forced exercise, wheel running, and sedentary. After a 8- weeks of the intervention, all mice were placed on a treadmill and forced to run for 30 minutes. Blood was collected from the mice prior to exercise, immediately following exercise, and one hour post exercise. Plasma corticosterone levels were assessed using an ELISA. 3-color flow cytometry was used to assess blood leukocytes. We found that despite treadmill acclimation in the forced exercise group, there was no significant difference between groups in corticosterone or leukocyte levels when forced to run on a treadmill. All groups showed a spike in corticosterone levels immediately following exercise which returned to baseline at one-hour post