A Conversation with Tim O’Brien

Tim O’Brien is the author of The Things They Carried. Based on his experiences as a foot soldier during the Vietnam War, the short-story collection published in 1990 helped to define Vietnam War literature and is now widely taught in middle- and high-school curricula. O’Brien’s other books include the novels July, July; In the Lake of the Woods; and Going After Cacciato. His work has earned a National Book Award, the Richard C. Holbrooke Distinguished Achievement Award, and the Pritzker Military Library Literature Award. Now retired from teaching, O’Brien served as the endowed chair of the MFA program at the University of Texas San Marcos biannually from 2003 to 2012

Surfactant-induced migration of a spherical drop in Stokes flow

In Stokes flows, symmetry considerations dictate that a neutrally-buoyant spherical particle will not migrate laterally with respect to the local flow direction. We show that a loss of symmetry due to flow-induced surfactant redistribution leads to cross-stream drift of a spherical drop in Poiseuille flow. We derive analytical expressions for the migration velocity in the limit of small non-uniformities in the surfactant distribution, corresponding to weak-flow conditions or a high-viscosity drop. The analysis predicts that the direction of migration is always towards the flow centerline.Comment: Significant extension with additional text, figures, equations, et

The Anderson-Mott transition induced by hole-doping in Nd1-xTiO3

The insulator/metal transition induced by hole-doping due to neodymium vacancies of the Mott- Hubbard antiferromagnetic insulator, Nd1-xTiO3, is studied over the composition range 0.010(6) < x < 0.243(10). Insulating p-types conduction is found for x < 0.071(10). Anderson localization in the presence of a Mott-Hubbard gap, is the dominant localization mechanism for the range of 0.074(10) < x < 0.089(1) samples. For x < 0.089(1), n-type conduction is observed and the activation energy extrapolates to zero by x < 0.1. The 0.095(8) < x < 0.203(10) samples are Fermi-liquid metals and the effects of strong electronic correlations are evident near the metal-to-insulator boundaries in features such as large Fermi liquid T2 coefficients. For 0.074(9) < x < 0.112(4), a weak negative magnetoresistance is found below ~ 15 K and it is attributed to the interaction of conduction electrons with Nd3+ magnetic moments. Combining information from our companion study of the magnetic properties of Nd1-xTiO3 solid solution, a phase diagram is proposed. The main conclusions are that long range antiferromagnetic order disappears before the onset of metallic behavior and that the Anderson-Mott transition occurs over a finite range of doping levels. Our results differ from conclusions drawn from a similar study on the hole doped Nd1-xCaxTiO3 system which found the co-existence of antiferromagnetic order and metallic behavior and that the Mott transition occurs at a discrete doping level

Creating Lakes from Open Pit Mines: Processes and Considerations, Emphasis on Northern Environments

Creating Lakes from Open Pit Mines: Processes and Considerations, Emphasis on Northern Environments. This document summarizes the literature of mining pit lakes (through 2007), with a particular focus on issues that are likely to be of special relevance to the creation and management of pit lakes in northern climates. Pit lakes are simply waterbodies formed by filling the open pit left upon the completion of mining operations with water. Like natural lakes, mining pit lakes display a huge diversity in each of these subject areas. However, pit lakes are young and therefore are typically in a non-equilibrium state with respect to their rate of filling, water quality, and biology. Separate sections deal with different aspects of pit lakes, including their morphometry, geology, hydrogeology, geochemistry, and biology. Depending on the type and location of the mine, there may be opportunities to enhance the recreational or ecological benefits of a given pit lake, for example, by re-landscaping and re-vegetating the shoreline, by adding engineered habitat for aquatic life, and maintaining water quality. The creation of a pit lake may be a regulatory requirement to mitigate environmental impacts from mining operations, and/or be included as part of a closure and reclamation plan. Based on published case studies of pit lakes, large-scale bio-engineering projects have had mixed success. A common consensus is that manipulation of pit lake chemistry is difficult, expensive, and takes many years to achieve remediation goals. For this reason, it is prudent to take steps throughout mine operation to reduce the likelihood of future water quality problems upon closure. Also, it makes sense to engineer the lake in such a way that it will achieve its maximal end-use potential, whether it be permanent and safe storage of mine waste, habitat for aquatic life, recreation, or water supply

Formulation of hydrophobic peptides for skin delivery via coated microneedles

Microneedles (MNs) have been investigated as a minimally-invasive delivery technology for a range of active pharmaceutical ingredients (APIs). Various formulations and methods for coating the surface of MNs with therapeutics have been proposed and exemplified, predominantly for hydrophilic drugs and particulates. The development of effective MN delivery formulations for hydrophobic drugs is more challenging with dosing restrictions and the use of organic solvents impacting on both the bioactivity and the kinetics of drug release. In this study we propose a novel formulation that is suitable for MN coating of hydrophobic auto-antigen peptides currently being investigated for antigen specific immunotherapy (ASI) of type 1 diabetes. The formulation, comprising three co-solvents (water, 2-methyl-2-butanol and acetic acid) and polyvinylalcohol 2000 (PVA2000) can dissolve both hydrophilic and hydrophobic peptide auto-antigens at relatively high, and clinically relevant, concentrations (25 mg/ml or 12.5 mg/ml). The drug:excipient ratio is restricted to 10:1 w/w to maximise dose whilst ensuring that the dry-coated payload does not significantly impact on MN skin penetration performance. The coating formulation and process does not adversely affect the biological activity of the peptide. The delivery efficiency of the coated peptide into skin is influenced by a number of parameters. Electropolishing the metal MN surface increases delivery efficiency from 2.0 ± 1.0% to 59.9 ± 6.7%. An increased mass of peptide formulation per needle, from 0.37 μg to 2 μg peptide dose, resulted in a thicker coating and a 20% reduction in the efficiency of skin delivery. Other important performance parameters for coated MNs include the role of excipients in assisting dissolution from the MNs, the intrinsic hydrophobicity of the peptide and the species of skin model used in laboratory studies. This study therefore both exemplifies the potential of a novel formulation for coating hydrophobic and hydrophilic peptides onto MN devices and provides new insight into the factors that influence delivery efficiency from coated MNs. Importantly, the results provide guidance for identifying critical attributes of the formulation, coating process and delivery device, that confer reproducible and effective delivery from coated MNs, and thus contribute to the requirements of the regulators appraising these devices

Illuminating Collaboration in Emergency Helath Care Situations: Paramedic-Physician Collaboration and 3D Telepresence Technology

Introduction. This paper focuses on paramedics' perspectives regarding paramedic-physician collaboration today, and their perspectives regarding the potential of 3D telepresence technology in the future. Method. Interviews were conducted with forty practicing paramedics. Analysis. The interview data were analysed using open and axial coding. An agreement of 0.82 using Cohen's kappa inter-coder reliability measure was reached. After coding was completed themes and relationships among codes were synthesised using topic memos. Results. Paramedics expressed concern about the lack of respect and trust exhibited towards them by other medical professionals. They discussed how they paint the picture for physicians and the importance of the physician trusting the paramedic. They further reported 3D telepresence technology would make their work visible in ways not previously possible. They also reported the technology would require additional training, changes to existing financial models used in emergency health care, and increased access to physicians. Conclusions. Teaching collaboration skills and strategies to physicians and paramedics could benefit their collaboration today, and increase their readiness to effectively use collaboration technologies in the future

Illuminating collaboration in emergency health care situations:Paramedic-physician collaboration and 3D telepresence technology

Introduction. This paper focuses on paramedics\u27 perspectives regarding paramedic-physician collaboration today, and their perspectives regarding the potential of 3D telepresence technology in the future. Method. Interviews were conducted with forty practicing paramedics. Analysis. The interview data were analysed using open and axial coding. An agreement of 0.82 using Cohen\u27s kappa inter-coder reliability measure was reached. After coding was completed themes and relationships among codes were synthesised using topic memos. Results. Paramedics expressed concern about the lack of respect and trust exhibited towards them by other medical professionals. They discussed how they paint the picture for physicians and the importance of the physician trusting the paramedic. They further reported 3D telepresence technology would make their work visible in ways not previously possible. They also reported the technology would require additional training, changes to existing financial models used in emergency health care, and increased access to physicians. Conclusions. Teaching collaboration skills and strategies to physicians and paramedics could benefit their collaboration today, and increase their readiness to effectively use collaboration technologies in the future