145 research outputs found
Within-socket Myoelectric Prediction of Continuous Ankle Kinematics for Control of a Powered Transtibial Prosthesis
Objective. Powered robotic prostheses create a need for natural-feeling user interfaces and robust control schemes. Here, we examined the ability of a nonlinear autoregressive model to continuously map the kinematics of a transtibial prosthesis and electromyographic (EMG) activity recorded within socket to the future estimates of the prosthetic ankle angle in three transtibial amputees. Approach. Model performance was examined across subjects during level treadmill ambulation as a function of the size of the EMG sampling window and the temporal \u27prediction\u27 interval between the EMG/kinematic input and the model\u27s estimate of future ankle angle to characterize the trade-off between model error, sampling window and prediction interval. Main results. Across subjects, deviations in the estimated ankle angle from the actual movement were robust to variations in the EMG sampling window and increased systematically with prediction interval. For prediction intervals up to 150 ms, the average error in the model estimate of ankle angle across the gait cycle was less than 6°. EMG contributions to the model prediction varied across subjects but were consistently localized to the transitions to/from single to double limb support and captured variations from the typical ankle kinematics during level walking. Significance. The use of an autoregressive modeling approach to continuously predict joint kinematics using natural residual muscle activity provides opportunities for direct (transparent) control of a prosthetic joint by the user. The model\u27s predictive capability could prove particularly useful for overcoming delays in signal processing and actuation of the prosthesis, providing a more biomimetic ankle response
The Development of a Comprehensive Health Care Program for Patients with Active Tuberculosis
Concepts basic to effective medical care evolved from the development of a comprehensive health service program for patients with tuberculosis. The key to success was found in a basic philosophy underlying all interpersonal relationships-the conviction that all men are equal. This philosophy then became the motivating force behind the creation of a functioning multidisciplinary team in which there was developed a freedom of relationships between each team member, and between team members and patients. The effectiveness of this approach in comprehensive medical care was illustrated by examples of special services and programming which were designed to reach all levels of the patient population, including hard core problem patients
Exploration of transitional life events in individuals with Friedreich ataxia: Implications for genetic counseling
<p>Abstract</p> <p>Background</p> <p>Human development is a process of change, adaptation and growth. Throughout this process, transitional events mark important points in time when one's life course is significantly altered. This study captures transitional life events brought about or altered by Friedreich ataxia, a progressive chronic illness leading to disability, and the impact of these events on an affected individual's life course.</p> <p>Methods</p> <p>Forty-two adults with Friedreich ataxia (18-65y) were interviewed regarding their perceptions of transitional life events. Data from the interviews were coded and analyzed thematically using an iterative process.</p> <p>Results</p> <p>Identified transitions were either a direct outcome of Friedreich ataxia, or a developmental event altered by having the condition. Specifically, an awareness of symptoms, fear of falling and changes in mobility status were the most salient themes from the experience of living with Friedreich ataxia. Developmental events primarily influenced by the condition were one's relationships and life's work.</p> <p>Conclusions</p> <p>Friedreich ataxia increased the complexity and magnitude of transitional events for study participants. Transitional events commonly represented significant loss and presented challenges to self-esteem and identity. Findings from this study help alert professionals of potentially challenging times in patients' lives, which are influenced by chronic illness or disability. Implications for developmental counseling approaches are suggested for genetic counseling.</p> <p>Background</p> <p>Human development can be described in terms of key transitional events, or significant times of change. Transitional events initiate shifts in the meaning or direction of life and require the individual to develop skills or utilize coping strategies to adapt to a novel situation <abbrgrp><abbr bid="B1">1</abbr><abbr bid="B2">2</abbr></abbrgrp>. A successful transition has been defined as the development of a sense of mastery over the changed event <abbrgrp><abbr bid="B3">3</abbr></abbrgrp>.</p> <p>Transitions can be influenced by a variety of factors including one's stage of development, such as graduation from high school, historical events, including war, and idiosyncratic factors, such as health status <abbrgrp><abbr bid="B4">4</abbr><abbr bid="B5">5</abbr></abbrgrp>. Of particular interest in the present study are transitional life events, brought about or altered by progressive chronic illness and disability, and the impact of these events on the lives of affected individuals.</p> <p>It has been recognized that the clinical characteristics of a chronic illness or disability may alter the course and timing of many developmentally-related transitional events <abbrgrp><abbr bid="B6">6</abbr></abbrgrp>. For example, conditions associated with a shortened lifespan may cause an individual to pursue a career with a shorter course of training <abbrgrp><abbr bid="B6">6</abbr></abbrgrp>. Specific medical manifestations may also promote a lifestyle incongruent with developmental needs <abbrgrp><abbr bid="B6">6</abbr><abbr bid="B7">7</abbr></abbrgrp>. For example, an adolescent with a disability may have difficulty achieving autonomy because of his/her physical dependence on others.</p> <p>In addition to the aforementioned effects of chronic illness and disability on developmentally-related transitional events, a growing body of literature has described disease-related transitional events: those changes that are a direct result of chronic illness and disability. Diagnosis has received attention as being a key disease-related transitional event <abbrgrp><abbr bid="B8">8</abbr><abbr bid="B9">9</abbr></abbrgrp>. Studies have also noted other disease transitions related to illness trajectory <abbrgrp><abbr bid="B10">10</abbr></abbrgrp>, as the clinical features of the disease may require the individual to make specific adaptations. Disease-related events have also been described in terms of accompanying psychological processes, such as one's awareness of differences brought about by illness <abbrgrp><abbr bid="B11">11</abbr></abbrgrp>.</p> <p>While disease-related events are seemingly significant, the patient's perception of the events is varied. Some events may be perceived as positive experiences for the individual. For example, a diagnosis may end years of uncertainty. Some individuals may perceive these transitional events as insignificant, as they have accommodated to the continual change brought about by a chronic disease <abbrgrp><abbr bid="B12">12</abbr><abbr bid="B13">13</abbr></abbrgrp>.</p> <p>The aforementioned impact of disability and chronic illness on transitional events may create psychological stress. Developed by Lazarus and Folkman, the Transitional Model of Stress and Coping describes the process of adaptation to a health condition <abbrgrp><abbr bid="B14">14</abbr></abbrgrp>. This model purports that individuals first appraise a stressor and then utilize a variety of coping strategies in order to meet the stressor's demands <abbrgrp><abbr bid="B14">14</abbr></abbrgrp>. Thus, in the context of chronic illness, the ability of the individual to cope successfully with the stress of a health threat contributes to the process of overall adaptation to the condition.</p> <p>The process of adaptation can be more complex when the chronic illness or disability is progressive. Each transition brought about or altered by the disability may also represent additional loss, including the loss of future plans, freedom in social life and the ability to participate in hobbies <abbrgrp><abbr bid="B15">15</abbr></abbrgrp>. These losses may be accompanied by grief, uncertainty, and a continual need for adaptation <abbrgrp><abbr bid="B16">16</abbr><abbr bid="B17">17</abbr></abbrgrp>.</p> <p>Friedreich ataxia (FRDA) is one example of a progressive disorder, leading to adolescent and adult onset disability. To better understand patients' perceptions of key transitional events and the factors perceived to facilitate progression through these events, individuals with FRDA were interviewed.</p> <p>FRDA is a rare, progressive, neurodegenerative disorder affecting approximately one in 30,000 people in the United States <abbrgrp><abbr bid="B18">18</abbr></abbrgrp>. It equally affects both men and women. Individuals with FRDA experience progressive muscle weakness and loss of coordination in the arms and legs. For most patients, ataxia leads to motor incapacitation and full-time use of a wheelchair, commonly by the late teens or early twenties. Other complications such as vision and hearing impairment, dysarthria, scoliosis, diabetes mellitus and hypertrophic cardiomyopathy may occur <abbrgrp><abbr bid="B19">19</abbr><abbr bid="B20">20</abbr></abbrgrp>. Cardiomyopathy and respiratory difficulties often lead to premature death at an average age of 37 years <abbrgrp><abbr bid="B21">21</abbr></abbrgrp>. Currently, there are no treatments or cures for FRDA. Little is known about the specific psychological or psychosocial effects of the condition.</p> <p>FRDA is an autosomal recessive condition. The typical molecular basis of Friedreich ataxia is the expansion of a GAA trinucleotide repeat in both copies of the <it>FXN </it>gene <abbrgrp><abbr bid="B22">22</abbr></abbrgrp>. Age of onset usually occurs in late childhood or early adolescence. However, the availability of genetic testing has identified affected individuals with an adult form of the condition. This late-onset form is thought to represent approximately 10-15% of the total FRDA population <abbrgrp><abbr bid="B23">23</abbr></abbrgrp>.</p> <p>Health care providers of individuals with progressive, neurodegenerative disorders can help facilitate their patients' progression through transitional events. Data suggest that improvements should be made in the care of these individuals. Shaw et al. <abbrgrp><abbr bid="B24">24</abbr></abbrgrp> found that individualized care that helps to prepare patients for transition is beneficial. Beisecker et al. <abbrgrp><abbr bid="B25">25</abbr></abbrgrp> found that patients desire not only physical care from their providers, but also emotional and psychosocial support.</p> <p>Genetic counselors have an important opportunity to help patients with neuromuscular disorders progress through transitional events, as several of these conditions have a genetic etiology. Genetic counselors in pediatric and adult settings often develop long-term relationships with patients, due to follow-up care. This extended relationship is becoming increasingly common as genetic counselors move into various medical sub-specialties, such as neurology, ophthalmology, oncology and cardiology.</p> <p>The role of the genetic counselor in addressing the psychosocial needs of patients has been advocated, but rarely framed in the context of developmental events <abbrgrp><abbr bid="B26">26</abbr></abbrgrp>. Data suggest that patients may not expect a genetic counselor to address psychosocial needs <abbrgrp><abbr bid="B27">27</abbr></abbrgrp>. In a survey of genetic counseling patients, Wertz <abbrgrp><abbr bid="B28">28</abbr></abbrgrp> found a majority of respondents understood genetic conditions to have a moderate to serious effect on family life and finances, while almost half perceived there to be an effect on the spouse, quality of life, and the relationship between home and work. However, these topics were reportedly not discussed within genetic counseling sessions <abbrgrp><abbr bid="B27">27</abbr><abbr bid="B28">28</abbr></abbrgrp>. Overall, there is limited information about the experiences of transitional life events in FRDA, as well as a lack of recommendations for genetic counselors and other health care providers to assist patients through these events.</p> <p>Our study investigated perceptions of patients with Friedreich ataxia to 1) identify key transitional events and specific needs associated with events; 2) describe perception of factors to facilitate progression through the identified events; and 3) explore the actual or potential role of the health care provider in facilitating adaptation to the identified events. Data were used to make suggestions for developmental genetic counseling approaches in the context of ongoing care of clients with hereditary, progressive, neurodegenerative conditions.</p
TCR deep sequencing of transgenic RAG-1-deficient mice reveals endogenous TCR recombination: a cause for caution
The utility of Tâcell receptor (TCR) transgenic mice in medical research has been considerable, with applications ranging from basic biology all the way to translational and clinical investigations. Crossing of TCR transgenic mice with either recombinationâactivating gene (RAG)â1 or RAGâ2 knockouts is frequently used to generate mice with a monoclonal Tâcell repertoire. However, low level productive TCR rearrangement has been reported in RAGâdeficient mice expressing transgenic TCRs. Using deep sequencing, we set out to directly examine and quantify the presence of these endogenous TCRs. Our demonstration that functional nontransgenic TCRs are present in nonmanipulated mice has wide reaching ramifications worthy of critical consideration
A Family of Water Immiscible, Dipolar Aprotic, Diamide Solvents from Succinic Acid
Three dipolar aprotic solvents were designed to possess high dipolarity and low toxicity: N , N , N ', N '-tetrabutylsuccindiamide (TBSA), N , N '-diethyl- N , N '-dibutylsuccindiamide (EBSA), N , N '-dimethyl- N , N '-dibutylsuccindiamide (MBSA). They were synthesized catalytically using a K60 silica catalyst in a solventless system. Their water-immiscibility stands out as an unusual and useful property for dipolar aprotic solvents. They were tested in a model Heck reaction, metal-organic framework syntheses, and a selection of polymer solubility experiments where their performances were found to be comparable to traditional solvents. Furthermore, MBSA was found to be suitable for the production of an industrially-relevant membrane from polyethersulphone. An integrated approach involving in silico analysis based on available experimental information, prediction model outcomes and read across data, as well as a panel of in vitro reporter gene assays covering a broad range of toxicological endpoints was used to assess toxicity. These in silico and in vitro tests suggested no alarming indications of toxicity in the new solvents
U.S. Army Small Space Update
In December 2010, the U.S. Army flew its first satellite in 50 years, the SMDC-ONE CubeSat. Placed in a very low orbit, the first SMDC-ONE mission lasted only 35 days but enjoyed great success in demonstrating the viability of CubeSats to perform exfiltration of unattended ground sensors data and serve as a communications relay between ground stations over 1000 land miles apart. The success of SMDC-ONE helped shape the U.S. Armyâs Space and Missile Defense Commandâs (SMDC) programmatic goals for finding new and innovative ways to implement space applications and technologies that aid the warfighter. Since 2010, SMDC has flown ten additional CubeSats including the three SMDC Nanosatellite Program-3 (SNaP) CubeSats currently on orbit (launched October 2015). This paper addresses several SMDC satellite-related development efforts including SNaP, Army Resilient Global On-the-move SATCOM (ARGOS) Ka-band communications microsatellites, Kestrel Eye (an imaging microsatellite), Kestrel Eye Ground Station (KEGS), Common Ground Station (CGS) for all future Army small satellites, supporting technologies including Small Business Innovative Research (SBIR) efforts, the Concepts Analysis Laboratory, SMDC Space Laboratory, the ACES RED effort and earlier responsive launch vehicle activities. Several of the lessons learned from previous as well as ongoing satellite activities are also covered
Linkage between solid-phase apportionment and bioaccessible arsenic, chromium and lead in soil from Glasgow, Scotland, UK
The chemical composition of soil from the Glasgow (UK) urban area was used to identify the controls on the availability of potentially harmful elements (PHEs) in soil to humans. Total and bioaccessible concentrations of arsenic (As), chromium (Cr) and lead (Pb) in 27 soil samples, collected from different land uses, were coupled to information on their solid-phase partitioning derived from sequential extraction data. The total element concentrations in the soils were in the range <0.1â135mgkgâ1 for As; 65â3680mgkgâ1 for Cr and 126â2160mgkgâ1 for Pb, with bioaccessible concentrations averaging 27, 5 and 27% of the total values, respectively. Land use does not appear to be a predictor of contamination; however, the history of the contamination is critically important. The Chemometric Identification of Substrates and Element Distribution (CISED) sequential chemical extraction and associated self-modelling mixture resolution analysis identified three sample groupings and 16 geochemically distinct phases (substrates). These were related to iron (n=3), aluminiumâsilicon (AlâSi; n=2), calcium (n=3), phosphorus (n=1), magnesium (Mg; n=3), manganese (n=1) and easily extractable (n=3), which was predominantly made up of sodium and sulphur. As, Cr and Pb were respectively found in 9, 10 and 12 of the identified phases, with bioaccessible As predominantly associated with easily extractable phases, bioaccessible Cr with the Mg-dominated phases and bioaccessible Pb with both the Mg-dominated and AlâSi phases. Using a combination of the Unified Barge Method to measure the bioaccessibility of PHEs and CISED to identify the geochemical sources has allowed a much better understanding of the complexity of PHE mobility in the Glasgow urban environment. This approach can be applied to other urban environments and cases of soil contamination, and made part of land-use planning
Origin and Evolution of Saturn's Ring System
The origin and long-term evolution of Saturn's rings is still an unsolved
problem in modern planetary science. In this chapter we review the current
state of our knowledge on this long-standing question for the main rings (A,
Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During
the Voyager era, models of evolutionary processes affecting the rings on long
time scales (erosion, viscous spreading, accretion, ballistic transport, etc.)
had suggested that Saturn's rings are not older than 100 My. In addition,
Saturn's large system of diffuse rings has been thought to be the result of
material loss from one or more of Saturn's satellites. In the Cassini era, high
spatial and spectral resolution data have allowed progress to be made on some
of these questions. Discoveries such as the ''propellers'' in the A ring, the
shape of ring-embedded moonlets, the clumps in the F Ring, and Enceladus' plume
provide new constraints on evolutionary processes in Saturn's rings. At the
same time, advances in numerical simulations over the last 20 years have opened
the way to realistic models of the rings's fine scale structure, and progress
in our understanding of the formation of the Solar System provides a
better-defined historical context in which to understand ring formation. All
these elements have important implications for the origin and long-term
evolution of Saturn's rings. They strengthen the idea that Saturn's rings are
very dynamical and rapidly evolving, while new arguments suggest that the rings
could be older than previously believed, provided that they are regularly
renewed. Key evolutionary processes, timescales and possible scenarios for the
rings's origin are reviewed in the light of tComment: Chapter 17 of the book ''Saturn After Cassini-Huygens'' Saturn from
Cassini-Huygens, Dougherty, M.K.; Esposito, L.W.; Krimigis, S.M. (Ed.) (2009)
537-57
Iconic dishes, culture and identity: the Christmas pudding and its hundred yearsâ journey in the USA, Australia, New Zealand and India
Asserting that recipes are textual evidences reflecting the society that produced them, this article explores the evolution of the recipes of the iconic Christmas pudding in the United States, Australia, New Zealand and India between the mid-nineteenth and the mid-twentieth centuries. Combining a micro-analysis of the recipes and the cookbook that provided them with contemporary testimonies, the article observes the dynamics revealed by the preparation and consumption of the pudding in these different societies. The findings demonstrate the relevance of national iconic dishes to the study of notions of home, migration and colonization, as well as the development of a new society and identity. They reveal how the preservation, transformation and even rejection of a traditional dish can be representative of the complex and sometimes conflicting relationships between colonists, migrants or new citizens and the places they live in
Effect of weathering product assemblages on Pb bioaccessibility in mine waste: implications for risk management
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