The impact of student loan debt on older adults and their retirement

The purpose of this creative component is to provide a comprehensive review of the literature that focuses on how student loan debt affects older adults and their retirement, with each section covering a specific aspect of the issue. The following collection of articles were written by government agencies, academic experts, and financial professionals, and they are directly related to the financial burden older adults experience from their student loan debt

Outcasts of the Universe: Shyness in Hawthorne and James

In Outcasts of the Universe, I argue that shyness is a modern dilemma, problematized by the broader shifts in American society: the expanding marketplace, the idealization of the self-made man, the rise of feminism and ever-changing gender roles, and a slow consolidation of the bachelor, the artist, and the aesthete into the stigmatized figure of the homosexual. By drawing on both the lives and works of Hawthorne and James, I theorize shyness as an alternative model of social and sexual engagement in the nineteenth century. In particular, I adapt the queer theory concept of closetedness, a concept that has no equivalent in heterosexual terms--unless it is shyness itself. In doing so, I contribute new insights to the fields of gender studies and to queer theory, both by expanding theories of the closet to heterosexual narratives and by exploring how closetedness might be psychologically overdetermined by shyness, melancholy, and introversion

A comparison of training methods to increase neck muscle strength [thesis]

The purpose of this study WHS to determine if increases in isometric cervical muscle strength and range of movement (ROM) generated from ten weeks of training on the Multi-cervical unit (MCU) is significantly greater than the increase gained by training with the dynaband. The high rate of neck injury in the Air Force from pilots exposed to high +Gz force has instigated this research. 32 healthy subjects were split into three groups, with one group as the control, one group training on the MCU and one group training on the dynaband. Training groups completed ten weeks of resistance training in their specified mode. Pre and post testing was performed on the MCU to measure changes in isometric strength and ROM. Comparisons were made using a one way ANOVA (

The Multiscale Biomechanics and Mechanochemistry of the Extracellular Matrix Protein Fibres: Collagen & Elastin

Collagen is the most abundant protein in the animal kingdom and, together with elastin, forms extensive fibrous networks that constitute the primary structure of the mammalian extracellular matrix, respectively endowing it with the tensile and elastic properties that fulfil its principal role as the passive framework of the body. The fibrous proteins are distinctly hierarchically organised from the molecular scale upwards; for example, the nanoscale tropocollagen monomer assembles in arrays that form the micrometer scale microfibrils and fibrils, and thence into collections of millimetre scale collagen fibres, that in-turn, constitute functional tissues such as skin, tendon and bone. Much is known about the structure at each of these individual scales – collagen being the most extensively researched – and the macromechanics of the fibres are well established. However, far less is known about the micromechanics of these proteins, in particular how the monomers influence the functional mechanics of the macroscopic fibres. In this thesis, I explore the multiscale mechanics of collagen and elastin fibres over a range of hydrations – with fibres in direct contact with aqueous solution, and progressively dehydrated in humidity-controlled environments. I use quasi-static tensile testing to probe the macroscopic mechanical response (Young’s modulus and stress relaxation) of the fibres, and employ Brillouin and Raman microscopy to assess the longitudinal modulus in the GHz range and corresponding molecular properties of the proteins. Brillouin microscopy is an emerging technique in the biomedical field. It enables the all-optical, contact-free and non-destructive testing of tissue micromechanics through detection of frequency shifted light scattered off thermally excited acoustic waves or “phonons” in the GHz range. As one of the first studies of Brillouin light scattering in these fibres, it sets the basis for further investigation of tissue biomechanics. In particular, I provide the full description of the protein fibre micromechanics by performing angular measurements using a so-called platelet-like configuration with sample mounted onto a reflective substrate at 45° angle to the excitation beam. I derive the high-frequency longitudinal modulus, and discuss the results in comparison to the Young’s modulus, in terms of the different frequency and spatial scale of the measurements. I obtained a full description of elasticity using Brillouin spectroscopy applied to dried fibres; however, obtaining the same description in hydrated fibres is a challenge, as the Brillouin spectrum is dominated by water. An assessment of the mechanical differences between type-I and type-II collagens is also given here. Water is known to be a primary determinant of tissue biomechanics, and I identified for the first time, the critical hydration ranges between 100 and 85% relative humidity (RH) for collagen, and around 85% RH for elastin, at which point each macroscopic fibre switched from viscoelastic to plastic-like behaviour. Dehydration below these critical points was shown to severely diminish collagen fibrillar sliding, and completely rob elastin of its ability to reversibly deform under strain. The Young’s modulus increased markedly below these hydrations, and I observed a parallel increase in the longitudinal modulus at high frequencies in each protein, indicating a concomitant increase in stiffness at the two scales. The major difference observed between the two fibrous proteins is that, in the case of elastin, I observe a two-fold increase in the longitudinal modulus as the hydration is decreased from 100 to 21% RH, whilst the Young’s modulus increases by two orders of magnitude. This discrepancy was not observed in collagen, which confirmed that the protein maintained its long-range order in the form of the triple helix at all hydrations employed in this work, whilst the elastin ultrastructure experiences a liquid-to-solid state change at a critical hydration. I demonstrate through the analysis of the low-wavenumber region (<500 cm-1) of the Raman spectrum, that the increase in molecular stiffness of both proteins, is reflected in an increase in torsional rigidity of the peptide backbone upon dehydration. Moreover in collagen, I observe a reduction in the number of inter-protein water bridges, which I propose causes a collapse of the lateral spacing between monomers and an increase in direct backbone-backbone hydrogen bonding, that further stiffens the fibre. Small strain induced reorientations of the amide III and C–C stretching modes in dehydrated collagen fibres suggest that macroscopic stresses may be transferred to the triple helix, otherwise left unperturbed in the hydrated state. I postulate that this is a result of the degraded intra- and interfibrillar sliding mechanism below the critical hydration. Hence in its dehydrated state, the collagen whole-fibre mechanics are similar to those at the molecular scale. The role of proteoglycans and glycosaminoglycans and their potential connection to hydration, is also discussed. In agreement with previous work, I found no Raman spectral changes as a result of stretching hydrated elastin fibres, indicating that even large strains e.g. 80%, have no significant effect on the structural scale probed by Raman microscopy, nor in the air-dried state where the brittle fibres break at low strains. I suggest this may imply a limited sensitivity of Raman bands to these changes, possibly an indication of elastin’s dynamic ultrastructure, or that stress is dissipated at a higher level of the fibre structure. On the macroscopic scale, it is the poroelastic nature of elastin which controls the stress relaxation under strain, and the elastic recovery is mediated by an interplay of hydrophobic interactions and hydration forces

Operating room first case start times: a metric to assess systems-based practice milestones?

BACKGROUND: Resident competence in peri-operative care is a reflection on education and cost-efficiency. Inspecting pre-existing operating room metrics for performance outliers may be a potential solution for assessing competence. Statistical correlation of problematic benchmarks may reveal future opportunities for educational intervention. METHODS: Case-log database review yielded 3071 surgical cases involving residents over the course of 5 years. Surgery anticipated and actual start times were evaluated for delays and residents were assessed using the days of resident training performed at the time of each corresponding case. Other variables recorded included day of week, attending anesthesiologist name, attending surgeon name, patient age, sex, American Society of Anesthesiologists physical status classification (ASA PS), and in-patient versus day surgery status. Mixed-effect, multi-variable, linear regression determined independent determinants of delay time. RESULTS: The analysis identified day of the week (F = 25.65, P \u3c 0.0001), days of training (F = 8.39, P = 0.0038), attending surgeon (F = 2.67, P \u3c 0.0001), and anesthesiology resident (F = 1.67, P = 0.0012) as independent predictors of delay time for first-start cases, with an overall regression model F = 3.09, r2 = 0.186, and P \u3c 0.0001. CONCLUSIONS: The day of the week and attending surgeon demonstrated significant impact of case delay compared to resident days trained. If a learning curve for first-case start punctuality exists for anesthesiology residents, it is subtle and irrelevant to operating room efficiency. The regression model accounted for only 19% of the variability in the outcome of delay time, indicating a multitude of additional unidentified factors contributing to operating room efficiency

Binary neutron star mergers: a jet engine for short gamma-ray bursts

We perform magnetohydrodynamic simulations in full general relativity (GRMHD) of quasi-circular, equal-mass, binary neutron stars that undergo merger. The initial stars are irrotational, $n=1$ polytropes and are magnetized. We explore two types of magnetic-field geometries: one where each star is endowed with a dipole magnetic field extending from the interior into the exterior, as in a pulsar, and the other where the dipole field is initially confined to the interior. In both cases the adopted magnetic fields are initially dynamically unimportant. The merger outcome is a hypermassive neutron star that undergoes delayed collapse to a black hole (spin parameter $a/M_{\rm BH} \sim 0.74$) immersed in a magnetized accretion disk. About $4000M \sim 60(M_{\rm NS}/1.625M_\odot)$ ms following merger, the region above the black hole poles becomes strongly magnetized, and a collimated, mildly relativistic outflow --- an incipient jet --- is launched. The lifetime of the accretion disk, which likely equals the lifetime of the jet, is $\Delta t \sim 0.1 (M_{\rm NS}/1.625M_\odot)$ s. In contrast to black hole--neutron star mergers, we find that incipient jets are launched even when the initial magnetic field is confined to the interior of the stars.Comment: 6 pages, 3 figures, 1 table, matches published versio

Modelling the impact of micro generation on the electrical distribution system

In the UK and elsewhere there is considerable debate as to the future form of the electricity distribution system. The coming years will see a rise in the amount of micro-generation connected to the network at low voltages and the emergence of highly-distributed power systems (HDPS). However, there is considerable uncertainty as to the impact that this micro-generation will have on the quality of power supplied to our homes or to the stability of the electricity system as a whole. To address these engineering challenges the UK Engineering and Physical Sciences Research Council (EPSRC) is funding a three year research programme featuring a multi-disciplinary team from a variety of UK Universities: Supergen HDPS. This paper documents one piece of work emerging from the consortium, where a multi-tool approach is used to analyse the impact of micro-generation on the electricity system. This used a building simulation tool to produce electrical generation profiles for domestic cogeneration device models. These, along with profiles produced for other micro-generation technology models and electrical load profiles are then replicated and aggregated using a customised statistical approach. The profiles were then used as boundary conditions for a set of electrical load flow simulations on a model of a section of real network, where the number of microgenerators was varied according to different scenarios for the future of the UK electricity grid. The results indicate that a significant number of micro-generation devices can be accommodated before any power quality problems arise, however this is dependent upon maintaining a robust central grid