7,318 research outputs found

    Dying ‘on time’ in dementia

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    The fear of suffering dementia may lead to people signing an Advance Euthanasia Directive to make provision for health care decisions in the event that he/she becomes unable to make those decisions. However, Advance Euthanasia Directives are rarely adhered to in the case of dementia because the symptoms of dementia conflict with the due care criteria; a person requesting euthanasia must be able to confirm this request at time of death and must be undergoing unbearable and hopeless suffering. Once dementia has progressed, the euthanasia ‘wish’ can no longer be confirmed, and assessing suffering in a person with dementia is nearly impossible. This means that for a euthanasia request to be successful you have to perform the euthanasia early enough, while the patient is still cognitively competent. The risk in doing so is that the patient may lose years of their life that could have been full of quality. Postponing euthanasia in dementia could result in euthanasia not being possible and the person with dementia living a life that they did not want. This paper addresses how to decide what ‘on time’ is when it comes to dying with dementia through literature review, information visualisation and public debate

    Cannons to Spark Thermal-Fluid Canons

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    Hands-on projects are launch pads for sparking student interest. Specifically, design-build-test (DBT) projects can be effective tools for boosting students’ confidence in their ability to apply theoretical knowledge to practical engineering. Recognizing the need for relating the theoretical aspects of thermodynamics to its application, an air cannon design-build-test project was envisioned and implemented. Air cannons can be simple and inexpensive to construct, while offering a robust platform to explore thermodynamics, heat transfer, and fluid mechanics concepts. At the same time, the ability to launch projectiles from the cannons carries an obvious appeal for many students. An air cannon design project was integrated towards the beginning of a year-long thermal-fluid sciences course series. The primary aim of the project was for student teams to study how air cannons function and subsequently design a prototype that fits “customer” specifications. Each team constructed their cannons using PVC piping to launch acetal plastic projectiles. Students were additionally required to design a functional release valve mechanism to trigger the projectile launch. To aid in evaluation of their designs, students were introduced to a numerical-analytical modeling approach to explain air cannon behavior using principles of linear momentum conservation and ideal gas thermodynamics theory. Among other metrics, the performance of each student team was assessed based on (1) the ability of the custom trigger mechanism to fire the cannon over a range of initial reservoir pressures, (2) a thoughtful comparison among experimentally-measured and model-predicted muzzle velocities, and (3) documentation of the results of cannon design, realization, and operation. This paper discusses the implementation and relevant outcomes of the project. Based on student feedback, the project was well-received and anchored the often abstract thermal-fluid sciences concepts taught. The project also highlighted the challenges of applying theoretical equations to real-world problems and the vital need for experiments to improve accuracy of theoretical models. Exposure to this iterative approach to design emphasizes the practical aspects of engineering challenges. Overall, the project served its primary purpose of engaging students with thermodynamics concepts. With minor modifications in implementation, the project can appeal to students with a broader academic focus and experience

    Provoking the debate on euthanasia in dementia with design.

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    Dementia affects 47 million people worldwide. It is a collection or consequence of many illnesses with symptoms including deterioration in memory, thinking and behaviour; it is a terminal disease. The fear of dementia leads people to request euthanasia. Euthanasia in dementia rarely happens because the dementia symptoms conflict with the due care criteria; a person requesting euthanasia must confirm the request at time of death and must be undergoing hopeless suffering. Once dementia has progressed, the euthanasia ‘wish’ can no longer be confirmed, and assessing suffering in a person with dementia is hard. Having a reliable dementia diagnosis is essential in order to be able to make a decision for an ‘early’ euthanasia. This paper describes a Speculative Design to explore what options should be considered for receiving a dementia diagnosis in order to plan a death. A branding strategy was developed for the Planned Death company, who advocate an early diagnosis for making end-of-life decisions. The branding includes company identity, website, diagnostic kit, diagnostic delivery strategy, and end-of-life support. Additionally a short documentary was developed describing the Planned Death Company’s motivation and a client testimonial. Responses to the documentary were collected with a carefully selected group of participants through a survey and in-depth interviews. The responses were rich and sparked debate. Many new questions arose to do with patient autonomy and social structures

    Interplay of size and Landau quantizations in the de Haas-van Alphen oscillations of metallic nanowires

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    We examine the interplay between size quantization and Landau quantization in the De Haas-Van Alphen oscillations of clean, metallic nanowires in a longitudinal magnetic field for `hard' boundary conditions, i.e. those of an infinite round well, as opposed to the `soft' parabolically confined boundary conditions previously treated in Alexandrov and Kabanov (Phys. Rev. Lett. {\bf 95}, 076601 (2005) (AK)). We find that there exist {\em two} fundamental frequencies as opposed to the one found in bulk systems and the three frequencies found by AK with soft boundary counditions. In addition, we find that the additional `magic resonances' of AK may be also observed in the infinite well case, though they are now damped. We also compare the numerically generated energy spectrum of the infinite well potential with that of our analytic approximation, and compare calculations of the oscillatory portions of the thermodynamic quantities for both models.Comment: Title changed, paper streamlined on suggestion of referrees, typos corrected, numerical error in figs 2 and 3 corrected and final result simplified -- two not three frequencies (as in the previous version) are observed. Abstract altered accordingly. Submitted to Physical Review

    Feral swine \u3ci\u3eSus scrofa\u3c/i\u3e: a new threat to the remaining breeding wetlands of the Vulnerable reticulated flatwoods salamander \u3ci\u3eAmbystoma bishopi\u3c/i\u3e

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    Feral swine Sus scrofa have been implicated as a major threat to sensitive habitats and ecosystems as well as threatened wildlife. Nevertheless, direct and indirect impacts on threatened species (especially small, fossorial species) are not well documented. The decline of the U.S. federally endangered reticulated flatwoods salamander Ambystoma bishopi, categorized as Vulnerable on the IUCN Red List, has been rapid and there are few remaining breeding locations for this species. The flatwoods salamander depends on complex herbaceous vegetation in all life stages, including eggs, larvae and adults. Historically sets of hog tracks have been observed only occasionally in the vicinity of monitored reticulated flatwoods salamander breeding wetlands, and damage to the wetlands had never been recorded. However, during the autumn–winter breeding season of 2013-2014 we observed a large increase in hog sign, including extensive rooting damage, in known flatwoods salamander breeding wetlands. Our objective was to assess the amount of hog sign and damage in these wetlands and to take corrective management actions to curb additional impacts. Of 28 wetlands surveyed for hog sign, presence was recorded at 68%, and damage at 54%. Of the 11 sites known to be occupied by flatwoods salamanders in 2013-2014, 64% had presence, and 55% had damage. We found that regular monitoring of disturbance in wetland habitats was a valuable tool to determine when intervention was needed and to assess the effectiveness of intervention. Habitat damage caused by feral hogs poses a potentially serious threat to the salamanders, which needs to be mitigated using methods to control and exclude hogs from this sensitive habitat

    The Innate Mononuclear Phagocyte Network Depletes B Lymphocytes through Fc Receptor–dependent Mechanisms during Anti-CD20 Antibody Immunotherapy

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    Anti-CD20 antibody immunotherapy effectively treats non-Hodgkin's lymphoma and autoimmune disease. However, the cellular and molecular pathways for B cell depletion remain undefined because human mechanistic studies are limited. Proposed mechanisms include antibody-, effector cell–, and complement-dependent cytotoxicity, the disruption of CD20 signaling pathways, and the induction of apoptosis. To identify the mechanisms for B cell depletion in vivo, a new mouse model for anti-CD20 immunotherapy was developed using a panel of twelve mouse anti–mouse CD20 monoclonal antibodies representing all four immunoglobulin G isotypes. Anti-CD20 antibodies rapidly depleted the vast majority of circulating and tissue B cells in an isotype-restricted manner that was completely dependent on effector cell Fc receptor expression. B cell depletion used both FcγRI- and FcγRIII-dependent pathways, whereas B cells were not eliminated in FcR common γ chain–deficient mice. Monocytes were the dominant effector cells for B cell depletion, with no demonstrable role for T or natural killer cells. Although most anti-CD20 antibodies activated complement in vitro, B cell depletion was completely effective in mice with genetic deficiencies in C3, C4, or C1q complement components. That the innate monocyte network depletes B cells through FcγR-dependent pathways during anti-CD20 immunotherapy has important clinical implications for anti-CD20 and other antibody-based therapies

    Precision asteroseismology of the pulsating white dwarf GD 1212 using a two-wheel-controlled Kepler spacecraft

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    We present a preliminary analysis of the cool pulsating white dwarf GD 1212, enabled by more than 11.5 days of space-based photometry obtained during an engineering test of the two-reaction-wheel-controlled Kepler spacecraft. We detect at least 19 independent pulsation modes, ranging from 828.2-1220.8 s, and at least 17 nonlinear combination frequencies of those independent pulsations. Our longest uninterrupted light curve, 9.0 days in length, evidences coherent difference frequencies at periods inaccessible from the ground, up to 14.5 hr, the longest-period signals ever detected in a pulsating white dwarf. These results mark some of the first science to come from a two-wheel-controlled Kepler spacecraft, proving the capability for unprecedented discoveries afforded by extending Kepler observations to the ecliptic.Comment: 8 pages, 4 figures, accepted for publication in The Astrophysical Journa

    Clinical and Radiologic Predictors of Parastomal Hernia Development After End Colostomy

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    OBJECTIVE. Parastomal hernia (PSH) is a common complication that can occur after end colostomy and may result in considerable morbidity. To select the best candidates for prophylactic measures, knowledge of preoperative PSH predictors is important. This study aimed to determine the value of clinical parameters, preoperative CT-based body metrics, and size of the abdominal wall defect created during end colostomy and measured at postoperative CT for predicting PSH development. MATERIALS AND METHODS. Sixty-five patients who underwent permanent end colostomy with at least 1 year of follow-up were included. On preoperative CT, waist circumference, abdominal wall and psoas muscle indexes, rectus abdominis muscle diameter and diastasis, intra- and extraabdominal fat mass, and presence of other hernias were assessed. On postoperative CT, size of the abdominal wall defect and the presence of PSH were determined. To identify independent predictors of PSH development, univariate analysis with the Kaplan-Meier method and multivariate Cox regression analysis were performed. RESULTS. PSH developed after surgery in 30 patients (46%). Three independent risk factors were identified: chronic obstructive pulmonary disease (COPD) as a comorbidity (hazard ratio [HR], 6.4; 95% CI, 1.9-22.0; p = 0.003), operation time longer than 395 minutes (HR, 3.9; 95% CI, 1.5-10.0; p = 0.005), and maximum aperture diameter of more than 34 mm (HR, 5.2; 95% CI, 2.1-12.7; p <0.001). PSH developed in all nine patients with a maximum abdominal wall defect diameter of more than 50 mm at the ostomy site. CONCLUSION. COPD, longer operation time, and larger abdominal wall defect at the colostomy site can predict PSH development. Intraoperative creation of an abdominal wall ostomy opening that is more than 34 mm in diameter should be avoided
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