Social Work’s Dynamic Role in Oncology: Providing Leadership for Environmental Responsiveness

Social work has a long standing relationship with healthcare. Beginning in the settlement house movement, social workers have provided a dynamic micro, mezzo, and macro role in medical settings. Social work’s ecological systems perspective allows for the inclusion of environmental and social justice factors in healthcare delivery. Ecological theory, epistemologically rooted in social work, is used as a conceptual framework throughout the three products, as the contextual environment is viewed as integral in understanding cancer patient experiences. The first product of this Banded Dissertation is a conceptual article detailing the need for culturally responsive practice methods in oncology care with rural Indigenous people. Oncology systems have increasingly invested in psychosocial care, yet disparities exist in psychosocial oncology care in the context of diverse rural settings. Social workers must become leaders in the healthcare arena in order to advocate and provide essential psychosocial, culturally responsive services to marginalized and underserved people. The second product includes qualitative research methodology with participants who are rural cancer patients in Illinois. The purpose of the second product was to explore psychosocial experiences of cancer patients who reside in a rural community in Illinois. The study used a rural cancer wellness center, Home of Hope, to recruit and interview 18 participants. The interviews were transcribed and organized into recurrent themes, highlighting the unique psychosocial experiences of the rural context. The third product is a commentary calling for an increased presence of the social work profession in the precision medicine movement. Precision medicine is essentially sequencing an individual’s genome in order to develop targeted medical interventions. The professional of social work, the article argues, has work to do in terms of becoming integrated with associated practice and ethics of this movement. This commentary was published in the journal Social Work in May 2016. This dissertation focuses on the intersectional nature of social work’s interface in specialty healthcare – particularly in rural and diverse contexts. The products are connected by the common thread of viewing the healthcare patient as “whole.” Ecological theory, epistemologically rooted in social work practice, values, and ethics, is used as a conceptual framework throughout the three products. The contextual rural environment is integral in understanding patient experiences in order to address healthcare disparities

Social Work’s Dynamic Role in Oncology: Providing Leadership for Environmental Responsiveness

Social work has a long standing relationship with healthcare. Beginning in the settlement house movement, social workers have provided a dynamic micro, mezzo, and macro role in medical settings. Social work’s ecological systems perspective allows for the inclusion of environmental and social justice factors in healthcare delivery. Ecological theory, epistemologically rooted in social work, is used as a conceptual framework throughout the three products, as the contextual environment is viewed as integral in understanding cancer patient experiences. The first product of this Banded Dissertation is a conceptual article detailing the need for culturally responsive practice methods in oncology care with rural Indigenous people. Oncology systems have increasingly invested in psychosocial care, yet disparities exist in psychosocial oncology care in the context of diverse rural settings. Social workers must become leaders in the healthcare arena in order to advocate and provide essential psychosocial, culturally responsive services to marginalized and underserved people. The second product includes qualitative research methodology with participants who are rural cancer patients in Illinois. The purpose of the second product was to explore psychosocial experiences of cancer patients who reside in a rural community in Illinois. The study used a rural cancer wellness center, Home of Hope, to recruit and interview 18 participants. The interviews were transcribed and organized into recurrent themes, highlighting the unique psychosocial experiences of the rural context. The third product is a commentary calling for an increased presence of the social work profession in the precision medicine movement. Precision medicine is essentially sequencing an individual’s genome in order to develop targeted medical interventions. The professional of social work, the article argues, has work to do in terms of becoming integrated with associated practice and ethics of this movement. This commentary was published in the journal Social Work in May 2016. This dissertation focuses on the intersectional nature of social work’s interface in specialty healthcare – particularly in rural and diverse contexts. The products are connected by the common thread of viewing the healthcare patient as “whole.” Ecological theory, epistemologically rooted in social work practice, values, and ethics, is used as a conceptual framework throughout the three products. The contextual rural environment is integral in understanding patient experiences in order to address healthcare disparities

Dynamics of Co-translational Membrane Protein Integration and Translocation via the Sec Translocon

An important aspect of cellular function is the correct targeting and delivery of newly synthesized proteins. Central to this task is the machinery of the Sec translocon, a transmembrane channel that is involved in both the translocation of nascent proteins across cell membranes and the integration of proteins into the membrane. Considerable experimental and computational effort has focused on the Sec translocon and its role in nascent protein biosynthesis, including the correct folding and expression of integral membrane proteins. However, the use of molecular simulation methods to explore Sec-facilitated protein biosynthesis is hindered by the large system sizes and long (i.e., minute) timescales involved. In this work, we describe the development and application of a coarse-grained simulation approach that addresses these challenges and allows for direct comparison with both in vivo and in vitro experiments. The method reproduces a wide range of experimental observations, providing new insights into the underlying molecular mechanisms, predictions for new experiments, and a strategy for the rational enhancement of membrane protein expression levels

Enhanced magnetic fields within a stratified layer

Mounting evidence from both seismology and numerical experiments on core composition suggests the existence of a layer of stably stratified fluid at the top of Earth’s outer core. In such a layer, a magnetostrophic force balance and suppressed radial motion lead to stringent constraints on the magnetic field, named Malkus constraints, which are a much more restrictive extension of the well known Taylor constraints. Here, we explore the consequences of such constraints for the structure of the core’s internal magnetic field. We provide a new simple derivation of these Malkus constraints, and show solutions exist which can be matched to any external potential field with arbitrary depth of stratified layer. From considerations of these magnetostatic Malkus constraints alone, it is therefore not possible to uniquely infer the depth of the stratified layer from external geomagnetic observations. We examine two models of the geomagnetic field defined within a spherical core, which obey the Taylor constraints in an inner convective region and the Malkus constraints in an outer stratified layer. When matched to a single-epoch geomagnetic potential field model, both models show that the toroidal magnetic field within the outer layer is about 100 times stronger compared to that in the inner region, taking a maximum value of 8 mT at a depth of 70 km. The dynamic regime of such a layer, modulated by suppressed radial motion but also a locally enhanced magnetic field, may therefore be quite distinct from that of any interior dynamo

Reconstruction of the thermal properties in a wave-type model of bio-heat transfer

Purpose: This study aims to at numerically retrieve five constant dimensional thermo-physical properties of a biological tissue from dimensionless boundary temperature measurements. Design/methodology/approach: The thermal-wave model of bio-heat transfer is used as an appropriate model because of its realism in situations in which the heat flux is extremely high or low and imposed over a short duration of time. For the numerical discretization, an unconditionally stable finite difference scheme used as a direct solver is developed. The sensitivity coefficients of the dimensionless boundary temperature measurements with respect to five constant dimensionless parameters appearing in a non-dimensionalised version of the governing hyperbolic model are computed. The retrieval of those dimensionless parameters, from both exact and noisy measurements, is successfully achieved by using a minimization procedure based on the MATLAB optimization toolbox routine lsqnonlin. The values of the five-dimensional parameters are recovered by inverting a nonlinear system of algebraic equations connecting those parameters to the dimensionless parameters whose values have already been recovered. Findings: Accurate and stable numerical solutions for the unknown thermo-physical properties of a biological tissue from dimensionless boundary temperature measurements are obtained using the proposed numerical procedure. Research limitations/implications: The current investigation is limited to the retrieval of constant physical properties, but future work will investigate the reconstruction of the space-dependent blood perfusion coefficient. Practical implications: As noise inherently present in practical measurements is inverted, the paper is of practical significance and models a real-world situation. Social implications: The findings of the present paper are of considerable significance and interest to practitioners in the biomedical engineering and medical physics sectors. Originality/value: In comparison to Alkhwaji et al. (2012), the novelty and contribution of this work are as follows: considering the more general and realistic thermal-wave model of bio-heat transfer, accounting for a relaxation time; allowing for the tissue to have a finite size; and reconstructing five thermally significant dimensional parameters

A Krylov subspace algorithm for evaluating the phi-functions appearing in exponential integrators

We develop an algorithm for computing the solution of a large system of linear ordinary differential equations (ODEs) with polynomial inhomogeneity. This is equivalent to computing the action of a certain matrix function on the vector representing the initial condition. The matrix function is a linear combination of the matrix exponential and other functions related to the exponential (the so-called phi-functions). Such computations are the major computational burden in the implementation of exponential integrators, which can solve general ODEs. Our approach is to compute the action of the matrix function by constructing a Krylov subspace using Arnoldi or Lanczos iteration and projecting the function on this subspace. This is combined with time-stepping to prevent the Krylov subspace from growing too large. The algorithm is fully adaptive: it varies both the size of the time steps and the dimension of the Krylov subspace to reach the required accuracy. We implement this algorithm in the Matlab function phipm and we give instructions on how to obtain and use this function. Various numerical experiments show that the phipm function is often significantly more efficient than the state-of-the-art.Comment: 20 pages, 3 colour figures, code available from http://www.maths.leeds.ac.uk/~jitse/software.html . v2: Various changes to improve presentation as suggested by the refere

Solving the Vlasov–Maxwell equations using Hamiltonian splitting

In this paper, the numerical discretizations based on Hamiltonian splitting for solving the Vlasov–Maxwell system are constructed. We reformulate the Vlasov–Maxwell system in Morrison–Marsden–Weinstein Poisson bracket form. Then the Hamiltonian of this system is split into five parts, with which five corresponding Hamiltonian subsystems are obtained. The splitting method in time is derived by composing the solutions to these five subsystems. Combining the splitting method in time with the Fourier spectral method and finite volume method in space gives the full numerical discretizations which possess good conservation for the conserved quantities including energy, momentum, charge, etc. In numerical experiments, we simulate the Landau damping, Weibel instability and Bernstein wave to verify the numerical algorithms

Computing stability of multi-dimensional travelling waves

We present a numerical method for computing the pure-point spectrum associated with the linear stability of multi-dimensional travelling fronts to parabolic nonlinear systems. Our method is based on the Evans function shooting approach. Transverse to the direction of propagation we project the spectral equations onto a finite Fourier basis. This generates a large, linear, one-dimensional system of equations for the longitudinal Fourier coefficients. We construct the stable and unstable solution subspaces associated with the longitudinal far-field zero boundary conditions, retaining only the information required for matching, by integrating the Riccati equations associated with the underlying Grassmannian manifolds. The Evans function is then the matching condition measuring the linear dependence of the stable and unstable subspaces and thus determines eigenvalues. As a model application, we study the stability of two-dimensional wrinkled front solutions to a cubic autocatalysis model system. We compare our shooting approach with the continuous orthogonalization method of Humpherys and Zumbrun. We then also compare these with standard projection methods that directly project the spectral problem onto a finite multi-dimensional basis satisfying the boundary conditions.Comment: 23 pages, 9 figures (some in colour). v2: added details and other changes to presentation after referees' comments, now 26 page

Design of perovskite/crystalline-silicon monolithic tandem solar cells

We present an optical model implemented in the commercial software SETFOS 4.6 for simulating perovskite/silicon monolithic tandem solar cells that exploit light scattering structures. In a first step we validate the model with experimental data of tandem solar cells that either use front- or rear-side textures and extract the internal quantum efficiency of the methyl-ammonium lead iodide (MALI) perovskite sub-cell. In a next step, the software is used to investigate the potential of different device architectures featuring a monolithic integration between the perovskite and silicon sub-cells and exploiting rear- as well as front-side textures for improved light harvesting. We find that, considering the available contact materials, the p-i-n solar cell architecture is the most promising with respect to achievable photocurrent for both flat and textured wafers. Finally, cesium-formamidinium-based perovskite materials with several bandgaps were synthetized, optically characterized and their potential in a tandem device was quantified by simulations. For the simulated layer stack and among the tested materials with bandgaps of 1.7 and 1.6 eV, the one with 1.6 eV bandgap was found to be the most promising, with a potential of reaching a power conversion efficiency of 31%. In order to achieve higher efficiencies using higher band-gap materials, parasitic absorptance in the blue spectral range should be further reduced

Force transduction creates long-ranged coupling in ribosomes stalled by arrest peptides

Force-sensitive arrest peptides regulate protein biosynthesis by stalling the ribosome as they are translated. Synthesis can be resumed when the nascent arrest peptide experiences a pulling force of sufficient magnitude to break the stall. Efficient stalling is dependent on the specific identity of a large number of amino acids, including amino acids which are tens of angstroms away from the peptidyl transferase center (PTC). The mechanism of force-induced restart and the role of these essential amino acids far from the PTC is currently unknown. We use hundreds of independent molecular dynamics trajectories spanning over 120 μs in combination with kinetic analysis to characterize the barriers along the force-induced restarting pathway for the arrest peptide SecM. We find that the essential amino acids far from the PTC play a major role in controlling the transduction of applied force. In successive states along the stall-breaking pathway, the applied force propagates up the nascent chain until it reaches the C-terminus of SecM and the PTC, inducing conformational changes that allow for restart of translation. A similar mechanism of force propagation through multiple states is observed in the VemP stall-breaking pathway, but secondary structure in VemP allows for heterogeneity in the order of transitions through intermediate states. Results from both arrest peptides explain how residues that are tens of angstroms away from the catalytic center of the ribosome impact stalling efficiency by mediating the response to an applied force and shielding the amino acids responsible for maintaining the stalled state of the PTC