A computer model of intracranial dynamics integrated to a full-scale patient simulator

The ability to visualize intracranial dynamics during simulated clinical scenarios is a valuable tool for teaching brain physiology and the consequences of different medical interventions on the brain. Studies have isolated physiologic variables and shown their effects on brain dynamics. However, no studies have shown the combined effects of these variables on intracranial dynamics. This brain model offers one approach that brings all these relationships together and shows how they affect the dynamics of the brain. The brain model obtains its physiologic inputs from a full-scale patient simulator which responds to clinical interventions. This integration allows individuals working on the patient simulator to see the effects of their actions on brain dynamics. The brain model gives a real-time display of intracranial events (cerebral metabolic rate, cerebral blood flow, cerebral blood volume, cerebral perfusion pressure, and intracranial pressure) and responds to changes in the pulmonary and cardiovascular condition of the patient simulator.     

The Celerity High-level API: C++20 for Accelerator Clusters

International Journal of Parallel Programming - Providing convenient APIs and notations for data parallelism which remain accessible for programmers while still providing good performance has been...     

A taxonomy of task-based parallel programming technologies for high-performance computing

Task-based programming models for shared memory—such as Cilk Plus and OpenMP 3—are well established and documented. However, with the increase in parallel, many-core, and heterogeneous systems, a number of research-driven projects have developed more diversified task-based support, employing various programming and runtime features. Unfortunately, despite the fact that dozens of different task-based systems exist today and are actively used for parallel and high-performance computing (HPC), no comprehensive overview or classification of task-based technologies for HPC exists. In this paper, we provide an initial task-focused taxonomy for HPC technologies, which covers both programming interfaces and runtime mechanisms. We demonstrate the usefulness of our taxonomy by classifying state-of-the-art task-based environments in use today.     

Determining Erodibility, Critical Shear Stress, and Allowable Discharge Estimates for Cohesive Channels: Case Study in the Powder River Basin of Wyoming

The continuous discharge of coalbed natural gas-produced (CBNG-produced) water within ephemeral, cohesive channels in the Powder River Basin (PRB) of Wyoming can result in significant erosion. A study was completed to investigate channel stability in an attempt to correlate cohesive soil properties to critical shear stress. An in situ jet device was used to determine critical shear stress (τc) and erodibility (kd); cohesive soil properties were determined following ASTM procedures for 25 reaches. The study sites were comprised of erodible to moderately resistant clays with τc ranging from 0.11?to?15.35?Pa and kd ranging from 0.27?to?2.38?cm3/N?s. A relationship between five cohesive soil characteristics and τc was developed and presented for use in deriving τc for similar sites. Allowable discharges for CBNG-produced water were also derived using τc and the tractive force method. An increase in the allowable discharge was found for channels in which vegetation was maintained. The information from this case study is critical to the development of a conservative methodology to establish allowable discharges while minimizing flow-induced instability.     

Breakdown of 3He-A superflow in low magnetic fields

Using a sensitive differential pressure gauge, we have measured the limits to dissipationless superflow in bulk superfluid ³He-A far from stabilizing walls. We report the first quantitative measurements of the breakdown of bulk superflow in the A phase. In addition to confirming the existence of a finite critical current in bulk uniform textures, we have discovered an unexpected tortuous texture in which there is an even larger critical current. These results indicate that the current theoretical models for determining textures are incomplete.     

Two Sample Tests in the Weibull Distribution

A test based on maximum likelihood estimators is given for testing the equality of the shape parameters in two Weibull distributions with the scale parameters unknown. Tests for the equality of the scale parameters are also presented along with a procedure for selecting the Weibull process with the larger mean life.     

Ultradian and diurnal cyclicity in the sleep states of newborn infants during the first two postnatal days

OBJECTIVE: The purpose of this study was to investigate both ultradian and diurnal cyclicity in the sleep states of newborn fullterm infants during the first 2 postnatal days. METHODS: The sleep of 31 healthy newborn infants was recorded continuously throughout the first 2 postnatal days, starting immediately after birth, using an automated Motility Monitoring System (MMS). The MMS consists of a pressure sensitive mattress pad connected to an amplifier and a small 24-h analog recorder. A single channel of analog signals produced by the infant's respiration and body movements was recorded and then scored in 30-s epochs for Active Sleep. Quiet Sleep, Active-Quiet Transition, Sleep-Wake Transition, and Wake. DATA ANALYSES: The 48 h of recording were divided into successive 12-h periods from 07:00 h to 19:00 h (day) and 19:00 h to 07:00 h (night), and all measures were derived for each day and night period. Both cross-sectional and repeated measures analyses were used because all babies were not represented in all day/night periods. RESULTS: Day/night differences in state variables: On both days, there was greater Wakefulness, shorter Quiet Sleep Bout Lengths, shorter Mean Sleep Periods and shorter Longest Sleep Periods during the daytime. On day 1 only, there was less Quiet Sleep, shorter Quiet Sleep Bout Lengths and more Sleep-Wake Transition during the daytime. On day 2, repeated measures analyses revealed two additional day/night differences: less Quiet Sleep and more Sleep-Wake Transition during the daytime. Day/night differences in Quiet Sleep cyclicity: 28 sleep periods met the criteria for analysis of Quiet Sleep cyclicity, and only six of these occurred during the daytime. Seventeen of 28 analyzable sleep periods showed significant Quiet Sleep cyclicity. Only two of these occurred during the daytime. CONCLUSIONS: Contrary to the prevailing view of developing sleep rhythms, the results of this study suggest that newborn infants exhibit both ultradian ad diurnal cyclicity in their sleep patterns from the earliest postnatal period.