The TheLMA project: Multi-GPU Implementation of the Lattice Boltzmann Method

International audienceIn this paper, we describe the implementation of a multi-graphical processing unit (GPU) fluid flow solver based on the lattice Boltzmann method (LBM). The LBM is a novel approach in computational fluid dynamics, with numerous interesting features from a computational, numerical, and physical standpoint. Our program is based on CUDA and uses POSIX threads to manage multiple computation devices. Using recently released hardware, our solver may therefore run eight GPUs in parallel, which allows us to perform simulations at a rather large scale. Performance and scalability are excellent, the speedup over sequential implementations being at least of two orders of magnitude. In addition, we discuss tiling and communication issues for present and forthcoming implementations

Increased Risk of Musculoskeletal Disorders and Mental Health Problems in Retired Professional Jockeys: A Cross-Sectional Study

To examine the prevalence of chronic disease and mental health problems in retired professional, male jockeys compared to an age-matched reference population. A cross-sectional study comparing data from a cohort of retired professional jockeys with an age-matched general population sample. Male participants (age range: 50–89 years old) were used to compare health outcomes of self-reported physician-diagnosed conditions: heart disease, stroke, diabetes, hypertension, osteoporosis, osteoarthritis, depression and anxiety between study populations. Conditional logistic regression models were used to estimate associations between study groups and health outcome. In total, 810 participants (135 retired professional male jockeys and 675 participants from the reference population) were included, with an average age of 64.7±9.9 years old. Increased odds of having osteoporosis (OR=6.5, 95%CI 2.1–20.5), osteoarthritis (OR=7.5, 95%CI 4.6–12.2), anxiety (OR=2.8, 95%CI 1.3–5.9) and depression (OR=2.6, 95%CI 1.3–5.7) were seen in the retired professional jockeys. No differences were found for the remaining health outcomes. Retired professional jockeys had increased odds of musculoskeletal disease and mental health problems compared to the general population. Understanding the prevalence of chronic disease and mental health problems in retired professional jockeys will help inform screening and intervention strategies for jockeys

Cardiovascular and Economic Outcomes After Initiation of Lipid-Lowering Therapy With Atorvastatin vs Simvastatin in an Employed Population

OBJECTIVE: To compare the risk of cardiovascular-related hospitalization, statin adherence, and direct (medical and drug) and indirect (disability and medically related absenteeism) costs in US employees in whom atorvastatin or simvastatin was newly prescribed

Synchronous and Non-Synchronous Semelparity in Sibling Species of Pulmonates

Diverse life histories have been documented in terrestrial pulmonates, which inhabit different regions in climate. Life history traits are often phenotypically plastic and vary depending on the environment. Thus, surveys using designs that control for the confounding effects of environment are needed to evaluate the evolutionary differences between populations of closely related species in the wild. We examined the life histories of sibling species of terrestrial pulmonate within two regions of similar climates. Bradybaena pellucida (BP) is endemic to Japanese islands, and has recently been expanding its distribution northeastward, whereas B. similaris (BS) has been introduced by humans into temperate and tropical regions worldwide. We found that these species exhibit discrete differences in population dynamics and life cycle, despite their close relatedness. The annual life cycle of BP is synchronized among individuals in a population. Thus, BP is univoltine with discontinuous generation. In contrast, BS individuals do not synchronize their growth or reproduction, and thus exhibit overlapping generations. Our results indicate that synchronized and non-synchronized population dynamics diverge relatively rapidly in semelparous pulmonates. This type of difference has not been documented in pulmonate life history, and may have been overlooked because only a few studies have explicitly compared life cycles of closely related species within the same climate. Our results provide a basis for further studies of life history evolution in pulmonates.ArticleZOOLOGICAL SCIENCE. 32(4):372-377 (2015)journal articl

Advances in the Use of LTS and HTS SQUIDS in Electromagnetic NDE

Of the electromagnetic sensors currently under investigation for nondestructive evaluation (NDE), the superconducting quantum interference device (SQUID) arguably has the greatest potential. The characteristics [1] which make it suitable for eddy current NDE are: high sensitivity even in large ambient fields (detection of sub-nT signals); operation from very low frequencies (a few Hz or less) to very high frequencies (potentially MHz) permitting detection of surface and subsurface flaws; and high spatial resolution. Spatial resolution is related to the physical size of the device, which is often less than 1 mm square, even when the need to maintain its other properties is taken into account. This often allows the SQUID to be treated theoretically and practically as an ideal point sensor. However, it must be operated in a cryogenic environment: low temperature superconductor (LTS) SQUIDs need liquid helium and liquid nitrogen (LN2) is needed even for high temperature superconductor (HTS) SQUIDs. This makes it difficult to reduce the specimen-to-sensor stand-off below approximately 1 mm.</p

The Bacterial Preparation OK432 Induces IL-12p70 Secretion in Human Dendritic Cells in a TLR3 Dependent Manner

Dendritic cells (DC) used in therapeutic cancer immunotherapy have to be able to stimulate T cells resulting in an immune response that can efficiently target the cancer cells. One of the critical hurdles has been the lack of IL-12p70 production when maturating the DC, which is rectified by using the bacterial preparation OK432 (trade name Picibanil) to mature the cells. In order to identify the mechanism behind OK432 stimulation of DC, we investigated the contribution of different TLR to examine their involvement in IL-12p70 production. By combining different inhibitors of TLR signaling, we demonstrate here that TLR3 is responsible for the IL-12p70 production of DC induced by OK432. Moreover, our data suggest that the ligand triggering IL-12p70 secretion upon TLR3 stimulation is sensitive to proteinase and partly also RNAse treatment. The fact that a bacterial compound like OK432 can activate the TLR3 pathway in human DC is a novel finding. OK432 demonstrates a critical ability to induce IL-12p70 production, which is of great relevance in DC based cancer immunotherapy

Jets and energy flow in photon-proton collisions at HERA

Properties of the hadronic final state in photoproduction events with large transverse energy are studied at the electron-proton collider HERA. Distributions of the transverse energy, jets and underlying event energy are compared to \overline{p}p data and QCD calculations. The comparisons show that the \gamma p events can be consistently described by QCD models including -- in addition to the primary hard scattering process -- interactions between the two beam remnants. The differential jet cross sections d\sigma/dE_T^{jet} and d\sigma/d\eta^{jet} are measured