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

Compositional nanodomain formation in hybrid formate perovskites

We report the synthesis and structural characterisation of three mixed-metal formate perovskite families [C(NH$_2$)$_3$]M$_{1-x}$Cu$_x$(HCOO)$_3$ (M = Mn, Zn, Mg). Using a combination of infrared spectroscopy, non-negative matrix factorization, and reverse Monte Carlo refinement, we show that the Mn- and Zn-containing compounds support compositional nanodomains resembling the polar nanoregions of conventional relaxor ferroelectrics. The M = Mg family exhibits a miscibility gap that we suggest reflects the limiting behaviour of nanodomain formation.Comment: 4 pages, 3 figure

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

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

Ontario School Teachers: A Gendered View of the 1930s

This particular article arises out of a longitudinal empirical study on teacher socialization with specific regard to relations of gender, ethnicity, and race. It focuses on a number of observations about Ontario teachers in the 1930s:1. The overall percentage of men in teaching rose, but much more so in rural areas than in the cities. 2. Salaries of teachers dropped considerably during this time. 3. There was a significant change in teacher certification procedures, within which gender played a large role. Salaries were also affected by these certification changes.4. Average ages of teachers increased significantly during this decade. 5. In general, teachers had more years of teaching experience than their colleagues did in the previous decade. However, there were significant gender differences in these figures. 6. Both formal and informal policies against the employment of married women as teachers were enforced. This article details these observations, and then discusses what significance they may have had, in the context of overall 'gender relations' among teachers in Ontario. A number of relevant sources for the 1930s were examined: annual reports of the Ontario Department of Education; annual reports, minutes, and handbooks of the Toronto Board of Education; and contemporary newspapers. In addition, reprinted transcripts of two groups of interviews have been drawn on—six men and women who taught (and later became principals) in Toronto in the 1930s, and a number of women teachers from the 1930s who were inter viewed for a 1980s study on women's experiences during the Depression

Harnessing oscillatory fluid behaviour to improve debris wash-out in ureteroscopy

In ureteroscopy, a common method for kidney stone removal, a ureteroscope is inserted into the patient’s kidney, through which working tools such as a laser are inserted. During the procedure, the renal space proximal to the scope tip is irrigated with fluid in order to clear stone particles and debris. However, even with continual fluid flow into and out of the kidney, stone dust may become trapped in vortical structures, significantly impairing the operating clinician’s field of view. Key to overcoming this challenge is a clear understanding of the flow patterns within an irrigated kidney calyx, and a modelling framework that enables to interrogate how different flow conditions impact on the wash-out time of debris. Previous theoretical studies have uncovered the interplay between fluid structure, in particular the presence of vortical regions, and dust washout, but only in a regime of steady inlet flow conditions. In this paper we model a kidney calyx in an idealised 2D cavity geometry, in which we investigate the presence and potential disturbance of vortical structures due to an oscillatory inlet condition, and the impact on dust washout, modelled as a passive tracer in the flow. By varying the flow amplitude and frequency at the inlet, we uncover a delicate relationship with vortex size and vortex disturbance, and we demonstrate the potential for significant decrease in wash-out time with low-frequency high-amplitude conditions. We then compare this result to the commonly used practice of flushing, a discrete and temporary increase in flow, and we also demonstrate the qualitative robustness of our findings to changes in cavity geometry

Age differences at sexual debut and subsequent reproductive health: Is there a link?

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Pulp, Vol. 4 No. 1

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