813 research outputs found
Making the grade: infrastructural semiotics and derivative market outcomes on the Chicago Board of Trade and New Orleans Cotton Exchange, 1856–1909
This paper contributes to a socio-technical analysis of derivatives by offering an infrastructural explanation of divergent outcomes on two early American futures markets. It takes as the starting-point of analysis the classification systems by which these futures markets were constitutively linked to underlying markets in agricultural commodities. Despite the formal similarity of these systems, their contrasting implementation–i.e. how grading was accomplished and integrated into practice–produced classifications with dissimilar semiotic qualities. This semiotic distinction is shown to have promoted divergent economic behaviours and outcomes on the two markets: high-risk speculation and volatility on the Chicago Board of Trade, low-risk hedging and stability on the New Orleans Cotton Exchange. The paper thus argues that treating classifications in their semiotic capacity yields an analysis that can connect foundational infrastructures and market-level outcomes in meaningful, non-deterministic ways
Infrastructure, ontology and meaning: the endogenous development of economic ideas
In contrast to work showing exogenous social influences on the production of economic ideas, this article asks how a market’s own infrastructure can endogenously shape practitioners’ economic perspectives. It investigates this question by comparing the evolution of opposed views on speculation across two 19th-century American futures markets. The analysis locates the origins of this divergence in features of the grading, receipting and contracting processes that linked these new derivative markets to underlying agricultural markets. This connective infrastructure both made possible new speculative practices and established market ontologies from which traders theorized the economic significance of those practices. These ontologies served as distinct cores around which incompatible constellations of ideas – including beliefs about price relations between spot and futures markets, the character of the global market and the motives and capabilities of speculators – were elaborated
A randomised feasibility study of serial magnetic resonance imaging to reduce treatment times in Charcot neuroarthropathy in people with diabetes (CADOM): A protocol
Background Charcot neuroarthropathy is a complication of peripheral neuropathy associated with diabetes which most frequently affects the lower limb. It can cause fractures and dislocations within the foot, which may progress to deformity and ulceration. Recommended treatment is immobilisation and offloading, with a below knee non-removable cast or boot. Duration of treatment varies from six months to more than one year. Small observational studies suggest that repeated assessment with Magnetic Resonance Imaging improves decision making about when to stop treatment, but this has not been tested in clinical trials. This study aims to explore the feasibility of using serial Magnetic Resonance Imaging without contrast in the monitoring of Charcot neuroarthropathy to reduce duration of immobilisation of the foot. A nested qualitative study aims to explore participants’ lived experience of Charcot neuroarthropathy and of taking part in the feasibility study. Methods We will undertake a two arm, open study, and randomise 60 people with a suspected or confirmed diagnosis of Charcot neuroarthropathy from five NHS, secondary care multidisciplinary Diabetic Foot Clinics across England. Participants will be randomised 1:1 to receive Magnetic Resonance Imaging at baseline and remission up to 12 months, with repeated foot temperature measurements and x-rays (standard care plus), or standard care plus with additional three-monthly Magnetic Resonance Imaging until remission up to 12 months (intervention). Time to confirmed remission of Charcot neuroarthropathy with off-loading treatment (days) and its variance will be used to inform sample size in a full-scale trial. We will look for opportunities to improve the protocols for monitoring techniques and the clinical, patient centred, and health economic measures used in a future study. For the nested qualitative study, we will invite a purposive sample of 10-14 people able to offer maximally varying experiences from the feasibility study to take part in semi-structured interviews to be analysed using thematic analysis. Discussion The study will inform the decision whether to proceed to a full-scale trial. It will also allow deeper understanding of the lived experience of Charcot neuroarthropathy, and factors that contribute to engagement in management and contribute to the development of more effective patient centred strategies. Trial registration ISRCTN, ISRCTN, 74101606. Registered on 6 November 2017, http://www.isrctn.com/ISRCTN74101606?q=CADom&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10&searchType=basic-searc
A systematic review of variables used to assess clinically acceptable alignment of unilateral transtibial amputees in the literature.
Prosthetic alignment is a subjective concept which lacks reliability. The outcome responsiveness to prosthetic alignment quality could help to improve subjective and instrument assisted prosthetic alignment. This study was aimed to review variables used to assess clinically acceptable alignment in the literature. The search was done in some databases including: Google Scholar, PubMed, EBSCO, EMBASE, ISI Web of Knowledge and Scopus. The first selection criterion was based on abstracts and titles to address the research questions of interest. The American Academy of Orthotics and Prosthetics checklists were used for paper risk of bias assessment. A total of 25 studies were included in this study. Twenty-four studies revealed the critics of standing position or walking to locate clinically acceptable alignment, only one study measured outcomes in both situations. A total of 253 adults with transtibial amputations and mean age of 48.71 years participated in included studies. The confidence level of included studies was low to moderate, and before-after trial was the most common study design (n = 19). The joint angle, load line location with respect to joints and center of pressure-related parameters were reported as sensitive outcomes to prosthetic alignment quality in standing posture. The amount of forces at various parts of gait cycle and time of events were sensitive to prosthetic alignment quality during walking. Standing balance and posture and temporal parameters of walking could help to locate clinically acceptable alignment.N/
How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers
Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program
Minimally invasive surgery for diabetic plantar foot ulcerations
Complications of diabetes mellitus constitute the most common indications for hospitalization and non-traumatic amputations in the USA. The most important risk factors for the development of diabetic foot ulcerations include the presence of peripheral neuropathy, vasculopathy, limited joint mobility, and pre-existing foot deformities. In our study, 500 diabetic patients treated for plantar forefoot ulcerations were enrolled in a prospective study from 2000 to 2008 at the Federal University of São Paulo, Brazil. Fifty-two patients in the study met the criteria and underwent surgical treatment consisting of percutaneous Achilles tendon lengthening to treat plantar forefoot ulcerations. The postoperative follow-up demonstrated prevention of recurrent foot ulcerations in 92% of these diabetic patients that maintained an improved foot function. In conclusion, our study supports that identification and treatment of ankle equinus in the diabetic population may potentially lead to decreased patient morbidity, including reduced risk for both reulceration, and potential lower extremity amputation
An overview of conservative treatment options for diabetic Charcot foot neuroarthropathy
Conservative management of Charcot foot neuroarthropathy remains efficacious for certain clinical scenarios. Treatment of the patient should take into account the stage of the Charcot neuroarthopathy, site(s) of involvement, presence or absence of ulceration, presence or absence of infection, overall medical status, and level of compliance. The authors present an overview of evidence-based non-operative treatment for diabetic Charcot neuroarthropathy with an emphasis on the most recent developments in therapy
Oxygen supplementation facilitating successful prosthetic fitting and rehabilitation of a patient with severe chronic obstructive pulmonary disease following trans-tibial amputation: a case report
Abstract Introduction Dysvascular amputations are increasingly performed in patients with underlying cardiac and pulmonary disorders. A limb prosthesis is rarely offered to patients with severe chronic obstructive pulmonary disease because of their inability to achieve the high energy expenditure required for prosthetic ambulation. We describe a case of successful prosthetic fitting and rehabilitation of a patient with severe chronic obstructive pulmonary disease with the aid of oxygen supplementation. Case presentation A 67-year-old aboriginal woman with severe chronic obstructive pulmonary disease and hypercapnic respiratory failure underwent right trans-tibial (below the knee) amputation for severe foot gangrene. An aggressive rehabilitation program of conditioning exercises and gait training utilizing oxygen therapy was initiated. She was custom-fitted with a right trans-tibial prosthesis. A rehabilitation program improved her strength, endurance and stump contracture, and she was able to walk for short distances with the prosthesis. The motion analysis studies showed a cadence of 73.5 steps per minute, a velocity of 0.29 meters per second and no difference in right and left step time and step length. Conclusion This case report illustrates that patients with significant severe chronic obstructive pulmonary disease can be successfully fitted with limb prostheses and undergo rehabilitation using supplemental oxygen along with optimization of their underlying comorbidities. Despite the paucity of published information in this area, prosthesis fitting and rehabilitation should be considered in patients who have undergone amputation and have severe chronic obstructive disease.</p
SuperBench: Improving Cloud AI Infrastructure Reliability with Proactive Validation
Reliability in cloud AI infrastructure is crucial for cloud service
providers, prompting the widespread use of hardware redundancies. However,
these redundancies can inadvertently lead to hidden degradation, so called
"gray failure", for AI workloads, significantly affecting end-to-end
performance and concealing performance issues, which complicates root cause
analysis for failures and regressions.
We introduce SuperBench, a proactive validation system for AI infrastructure
that mitigates hidden degradation caused by hardware redundancies and enhances
overall reliability. SuperBench features a comprehensive benchmark suite,
capable of evaluating individual hardware components and representing most real
AI workloads. It comprises a Validator which learns benchmark criteria to
clearly pinpoint defective components. Additionally, SuperBench incorporates a
Selector to balance validation time and issue-related penalties, enabling
optimal timing for validation execution with a tailored subset of benchmarks.
Through testbed evaluation and simulation, we demonstrate that SuperBench can
increase the mean time between incidents by up to 22.61x. SuperBench has been
successfully deployed in Azure production, validating hundreds of thousands of
GPUs over the last two years.Comment: USENIX ATC '2
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