Correlated Poincare indices for measuring heart rate variability

Poincare indices are usually applied to HRV to summarise long data sets collected over 24 hrs. Many applications of HRV are interested in dynamic, short term changes (0.85) between the indices for each of the 12 subjects (p<0.001) (particularly with the common measures SDNN, RMSSD, pNN50 and meanRR) were identified. These indices will not be used for further investigation of dynamic effects of fentanyl and midazolam, two sedative drugs used in anaesthesia and intensive care. Indices that proved less suitable for short term analysis (eg, presence of outliers, inability to produce a valid index with smaller number of beats) were also identified. A shortlist of Poincare indices that do not correlate strongly with commonly used measures may prove interesting in determining dynamic characteristics of the effect of sedative drugs on autonomic nervous system activity

Pulp, Vol. 4 No. 1

This is the fourth issue of Pulp.https://scholarworks.sfasu.edu/pulp/1003/thumbnail.jp

PCAdmix: Principal Components-Based Assignment of Ancestry along Each Chromosome in Individuals with Admixed Ancestry from Two or More Populations

Identifying ancestry along each chromosome in admixed individuals provides a wealth of information for understanding the population genetic history of admixture events and is valuable for admixture mapping and identifying recent targets of selection. We present PCAdmix (available at https://sites.google.com/site/pcadmix/home), a Principal Componentsbased algorithm for determining ancestry along each chromosome from a high-density, genome-wide set of phased single-nucleotide polymorphism (SNP) genotypes of admixed individuals. We compare our method to HAPMIX on simulated data from two ancestral populations, and we find high concordance between the methods. Our method also has better accuracy than LAMP when applied to three-population admixture, a situation as yet unaddressed by HAPMIX. Finally, we apply our method to a data set of four Latino populations with European, African, and Native American ancestry. We find evidence of assortative mating in each of the four populations, and we identify regions of shared ancestry that may be recent targets of selection and could serve as candidate regions for admixture-based association mapping

Perceptions of Poverty Families About the Incidence and Effect and Redress of Poverty in Omaha

Between March and May, 1965, 1112 families residing in nineteen census tracts in the City of Omaha were interviewed through the facilities of the Urban Studies Center of the Municipal University of Omaha with respect to various characteristics of their income, composition, and opinion as these items related to understanding the status of the econornica1ly underprivileged in their neighborhoods. The purpose of these interviews was to facilitate preparation of a community action program in Omaha capable of attacking some of the root causes of poverty and improving the conditions, present and future, of those families who were its victims. Quite obviously, improvement in economic conditions through appropriate policy decisions is dependent upon a diagnosis of the current character of those conditions. In great degree this diagnosis could be accomplished only through interviews with poverty families. These families were drawn from a sample of the population residing in the census tracts in which, according to information made available in the 1960 census for Omaha, ten percent or more of the families earned $3000 or less annually, and ten percent or more of the single persons earned$1500 or less during a like period. (A family is defined here as two or more persons living together and comprising a single household)

Mathematical modelling of unsteady flows during ureteroscopy

Ureteroscopy is a procedure used to treat kidney stones, which consists of passing a flexible tool known as a ureteroscope through the urinary system to access the kidney. The scope is hollow along its length, creating a working channel through which working tools can be passed. Once a stone is located, a laser fibre is inserted down the working channel to deliver a high-power laser which reduces the kidney stone to dust. Throughout the procedure constant fluid irrigation is delivered through the scope working channel, which fills and dilates the kidney cavity, and then exits via the space in between the ureteroscope and ureter. Often an access sheath is inserted within the ureter to provide better dilation of the channel. The fluid washes the dust created during lasering out of the kidney, providing the clinician with a clear field of view of the kidney interior via a camera at the tip of the scope. Traditionally this fluid irrigation is provided by a hanging saline bag at a level above the patient, producing a constant, gravity driven flow. Instead, we consider the case where the fluid is driven via a peristaltic pump, providing the clinician with better control over the irrigation delivery. Due to the nature of how these pumps operate, previously unseen time dependence is introduced to the flow, causing it to oscillate in time. Understanding the prevalence of these oscillations throughout the system is key to determining how this new method differs from the traditional set-up, and what benefits the improved delivery method can bring. This thesis is concerned with the mathematical modelling of oscillatory fluid irrigation throughout the ureteroscopy system, with an aim to determine the prevalence of the fluid oscillations throughout the system and how the time dependence can be harnessed to improve the procedure by decreasing dust wash-out times. We begin by modelling the flow throughout the cylindrical geometries of the system, namely the tubing connecting the pump and scope, the scope working channel with working tool inserted, and the access sheath with scope inserted. The flow is driven by an upstream oscillatory pressure, with atmospheric pressure at the outlet of the access sheath, where at the junctions between each section we assume continuity of flux and pressure. The model is solved analytically, and it is found that the flow and pressure oscillations are significantly dampened by the time they reach the kidney cavity due to the small radii of the ureteroscope working channel and working tool. The assumptions made at the junctions between each section are then addressed by numerically simulating the flow within these more complicated geometries. Alongside this, we present a model of the peristaltic pump used to drive the fluid, and show how the characteristics of the flow mean, frequency, and amplitude are related to pump rotations per minute. Both models are validated by comparing the theoretical predictions with experimental data sets and good agreement is shown. Next we turn to the modelling of fluid flow within the kidney cavity, and the transport of kidney stone dust within said fluid. To represent the cavity, we consider an idealised, two-dimensional, rectangular domain, with one inlet and two outlets on the same side of the domain. A parabolic, oscillatory inlet flow introduces the time-dependence to the system. The problem is solved numerically via finite element formulation. Dust wash-out time is used as a metric, and the parameters of the inflow are varied with an objective to reduce the wash-out time. It is found that an inlet flow which oscillates with a low frequency and high amplitude aids in disturbing vortical structures within the flow, leading to a significantly reduced dust wash-out time due to the resulting mixing effect. We go on to compare the wash-out times under this oscillatory regime to a simulation of a typical industry method termed flushing, and find that this new method performs favourably. The robustness of these results is then examined by demonstrating the impact of changes to the cavity geometry on dust wash-out times, and qualitatively similar wash-out results are seen for all geometries. Finally, the previous modelling efforts are combined together to create a model of the full ureteroscopy system. Fluid irrigation is modelled through tubing, to scope working channel, and into the kidney, before exiting via the access sheath, all driven by a flux which is determined from the pump model. In addition to this, we introduce the idea of an air dampener upstream of the ureteroscope to the model and consider the impact it has on the oscillatory flows downstream of the scope. The model shows that the air dampener effectively reduces the amplitude of the oscillations as intended. The predictions from the modelling are again validated by experimental data sets and good agreement is found by accounting for a scaling factor on the working tool resistance

Tolerogenic dendritic cells generated with dexamethasone and vitamin D3 regulate rheumatoid arthritis CD4⁺ T cells partly via transforming growth factor-β1

Tolerogenic dendritic cells (tolDC) are a new immunotherapeutic tool for the treatment of rheumatoid arthritis (RA) and other autoimmune disorders. We have established a method to generate stable tolDC by pharmacological modulation of human monocyte‐derived DC. These tolDC exert potent pro‐tolerogenic actions on CD4(+) T cells. Lack of interleukin (IL)−12p70 production is a key immunoregulatory attribute of tolDC but does not explain their action fully. Here we show that tolDC express transforming growth factor (TGF)‐β1 at both mRNA and protein levels, and that expression of this immunoregulatory cytokine is significantly higher in tolDC than in mature monocyte‐derived DC. By inhibiting TGF‐β1 signalling we demonstrate that tolDC regulate CD4(+) T cell responses in a manner that is at least partly dependent upon this cytokine. Crucially, we also show that while there is no significant difference in expression of TGF‐βRII on CD4(+) T cells from RA patients and healthy controls, RA patient CD4(+) T cells are measurably less responsive to TGF‐β1 than healthy control CD4(+) T cells [reduced TGF‐β‐induced mothers against decapentaplegic homologue (Smad)2/3 phosphorylation, forkhead box protein 3 (FoxP3) expression and suppression of (IFN)‐γ secretion]. However, CD4(+) T cells from RA patients can, nonetheless, be regulated efficiently by tolDC in a TGF‐β1‐dependent manner. This work is important for the design and development of future studies investigating the potential use of tolDC as a novel immunotherapy for the treatment of RA

Pulp, Vol. 4 No. 1

This is the fourth issue of Pulp.https://scholarworks.sfasu.edu/pulp/1003/thumbnail.jp

The Charging Process in a High-speed, Single-cylinder, Four-stroke Engine

Experimental measurements and theoretical calculations were made on an aircraft-type, single cylinder engine, in order to determine the physical nature of the inlet process, especially at high piston speeds. The engine was run at speeds from 1,500 to 2,600 r.p.m. (mean piston speeds of 1,370 to 2,380 feet per minute). Measurements were made of the cylinder pressure during the inlet stroke and of the power output and volumetric efficiency. Measurements were also made, with the engine not running, to determine the resistance and mass of air in the inlet valve port at various crank angles. Results of analysis indicate that mass has an appreciable effect, but friction plays the major part in restricting flow. The observed fact that the volumetric efficiency is considerably less than 100 percent is attributed to thermal effects. An estimate was made of the magnitude of these effects in the present case, and their general nature is discussed