3,149 research outputs found
Adaptive Sensor Data Acquisition for Gait Analysis
AbstractIn this paper a method is presented that uses one sensor configuration for both static and dynamic loading conditions to capture plantar pressure distribution values. In the gait analysis, different phases are from interest. The phases produces highly different signals and with conventional sensors and static data acquisition systems it is often difficult to achieve high precision measure- ments. An advanced programmable amplifier can be used to adapt the full resolution of the measurement system dynamically to the needs of the gait analyses. With the proposed system, it is possible to precisely measure the gait phases without changing any hardware. While the system is performing it is energy efficient as it only consumes power if needed. Furthermore, it is highly integrated and space saving. Thus, ideally suited for mobile outdoor applications. The technology used in this example can be applied to many different general sensor measurement questions in sports engineering
Wearable, Modular and Intelligent Sensor Laboratory
AbstractIn this paper, a modular sensor system for recording pressure distribution, 3D-acceleration, 3D-angular velocity, temperature and humidity in a shoe insole is presented. The intelligent sensor-insole is a measurement system that can be used in medical and sport related fields. Integrated sensors record physical parameters such as acceleration and or pressure which can also be used to trigger an additional feedback system. Through intelligent and high performant electronics, the feedback system is able to operate in real time. The combination of individually miniaturized systems, wireless data transmissions and a rechargeable battery enables the system for a wide field of application such as fall prevention, training analysis and motion optimization. Robust and miniaturized hardware components as well as wireless communication technology enable real-time processing of data. Measurement data can be stored locally on the measurement device for post analysis, as well as visualized on connected mobile devices such as smartphones or tablets. Aiming at using the system as a mobile and easy-to-use lab, both under laboratory conditions and in field. Applications like gait- and running analysis outside the laboratory, fall detection and activity monitoring in a home environment are possible. Due to the high performance of the system, the data pre-processing can be performed on the embedded system. Because the system supports wireless connections, it is possible to combine several of the systems to build a sensor network. Furthermore, it is possible to transmit the collected data to a cloud. The system will provide the measured data in different levels of complexity. For instance, the system is able to evaluate the data automatically and provide the results to experts such as physicians and coaches
Relation between homocysteine and biochemical bone turnover markers and bone mineral density in peri- and post-menopausal women
Background: Recently, increased plasma homocysteine (Hcy) has been suggested as an independent risk factor for osteoporotic fractures. Therefore, it is tempting to speculate that Hcy adversely affects bone metabolism. This study aimed to analyze the relation between Hcy and biochemical markers of bone metabolism and bone mineral density (BMD). Materials and methods: We investigated 143 peri- and post-menopausal women [median age (25th-75th percentile), 67 (57-75) years]. All subjects underwent a detailed medical examination, measurement of bone mineral density at lumbar spine (BMD-LS) and total hip (BMD-HIP), and fasting venous blood and urine sampling. Osteocalcin (OC), serum calcium (Ca), urinary desoxypyridinoline cross-links (DPD), osteoprotegerin (OPG) and soluble receptor activator of NF-κB ligand (sRANKL) were studied. Results: According to BMD subjects were classified as normal (n=24), osteopenic (n=51) or osteoporotic (n=68). Median Hcy did not differ between normal, osteopenic and osteoporotic subjects (p=0.647). Partial correlation analysis, controlling for the major confounders, age, creatinine, menopause and previous fractures, revealed significant correlations between Hcy and DPD (r=0.193, p=0.022), as well as between Hcy and Ca (r=0.170, p=0.045). After adjustment for the same confounders, subsequent regression analysis confirmed significant associations of Hcy with DPD and Ca. No significant relations could be observed between Hcy and BMD-LS, BMD-HIP, OC, OPG or sRANKL. Conclusion: Our results demonstrate weak, but significant, relations between Hcy and markers of organic and inorganic bone resorption, suggesting a mechanistic role of Hcy in bone metabolism. The relation between Hcy and bone resorption was not dependent on OPG or sRANK
Imperfect, boring, headed for change? 10 ways to improve academic CV assessments
Academic CVs play a major role in research assessment and in shaping academic fields by sorting and selecting promising researchers. Their role in structuring and prioritizing information is therefore significant and has recently been criticised for facilitating judgements based predominantly on narrow quantitative measures. In the blogpost, Josh Brown, Wolfgang Kaltenbrunner, Michaela Strinzel, Sarah de Rijcke and Michael Hill assess the changing landscape of research CVs and give ten recommendations for how they can be used more effectively in research assessment
On the concepts of radial and angular kinetic energies
We consider a general central-field system in D dimensions and show that the
division of the kinetic energy into radial and angular parts proceeds
differently in the wavefunction picture and the Weyl-Wigner phase-space
picture. Thus, the radial and angular kinetic energies are different quantities
in the two pictures, containing different physical information, but the
relation between them is well defined. We discuss this relation and illustrate
its nature by examples referring to a free particle and to a ground-state
hydrogen atom.Comment: 10 pages, 2 figures, accepted by Phys. Rev.
Stakes are High: Essays on Brazil and the Future of the Global Internet
This workbook seeks to provide some background to the Global Meeting on the Future of Internet Governance (NETmundial) scheduled for April 23rd and 24th 2014 in São Paulo, Brazil. It is designed to help outline the internet policy issues that are at stake and will be discussed at NETmundial, as well as background on internet policy in Brazil. The workbook includes essays on the history of the NETmundial meeting and the Marco Civil process in Brazil; some background on the environment in Germany—with particular attention to the link between the meeting and the Snowden case; questions of legitimacy surrounding open processes for lawmaking; and comments on the material presented to the organizing committee by official and unofficial commenters.
This workbook was produced as a part of the Internet Policy Observatory, a program at the Center for Global Communication Studies, the Annenberg School for Communication at the University of Pennsylvania. It was edited and curated by a steering committee including Ellery Roberts Biddle of Global Voices, Ronaldo Lemos of the Rio Institute for Technology and Society, and Monroe Price of the Annenberg School for Communication. They were assisted by Alexandra Esenler, Laura Schwartz-Henderson, and Briar Smith
Bone Loss after Allogeneic Haematopoietic Stem Cell Transplantation: A Pilot Study on the Use of Zoledronic Acid
Purpose. Bone loss is a common phenomenon following allogeneic haematopoietic stem cell transplantation (allo-HSCT). The study aimed on tolerance and efficacy of zoledronic acid (ZA) in patients after allo-HSCT. Methods. 40 patients' with osteoporosis or osteopenia were recruited on this phase II study. ZA was given at a dose of 4 mg IV every 3 months for 2 years (yrs). BMD was determined by dual-energy X-ray absorptiometry (LS lumbar spine, FH femur hip). Patients were evaluated for deoxypyridinoline (Dpd) and calcium excretion by longitudinal measurements. Results. 36 patients who had received at least 3 doses of ZA were evaluable. 26 patients had at least two BMD measurements since baseline (BMD group). Among these patients, BMD increased from 0.97 ± 0.15 to 1.10 ± 0.18 g/cm² (LS baseline—2 yrs, Δ+11.6 ± 6.0%, P < 0.001) and from 0.82 ± 0.10 to 0.91 ± 0.10 g/cm² (FH baseline—2 yrs, Δ+7.5 ± 7.0%, P < 0.001). Factors associated with an increase in BMD were younger age, female donor sex, and immunosuppression with CSA/MTX. Conclusion. ZA was generally well tolerated; it increases BMD and reduces Dpd excretion significantly in patients with bone loss after allo-HSCT
Arthritis induced by posttranslationally modified (citrullinated) fibrinogen in DR4-IE transgenic mice
Rheumatoid arthritis (RA) is a common autoimmune disease that afflicts the synovium of diarthrodial joints. The pathogenic mechanisms inciting this disease are not fully characterized, but may involve the loss of tolerance to posttranslationally modified (citrullinated) antigens. We have demonstrated that this modification leads to a selective increase in antigenic peptide affinity for major histocompatibility complex (MHC) class II molecules that carry the RA-associated shared epitope, such as HLA-DRB1*0401 (DR4). We describe the induction of arthritis in DR4-IE transgenic (tg) mice with citrullinated fibrinogen, a protein commonly found in inflamed synovial tissue and a frequent target of autoantibodies in RA patients. The disease induced in these mice was characterized by synovial hyperplasia followed by ankylosis, but lacked a conspicuous polymorphonuclear cell infiltrate. Immunological analysis of these mice through T cell epitope scanning and antibody microarray analysis identified a unique profile of citrulline-specific reactivity that was not found in DR4-IE tg mice immunized with unmodified fibrinogen or in wild-type C57BL/6 mice immunized with citrullinated fibrinogen, two conditions where arthritis was not observed. These observations directly implicate citrullinated fibrinogen as arthritogenic in the context of RA-associated MHC class II molecules
Review: optical fiber sensors for civil engineering applications
Optical fiber sensor (OFS) technologies have developed rapidly over the last few decades, and various types of OFS have found practical applications in the field of civil engineering. In this paper, which is resulting from the work of the RILEM technical committee “Optical fiber sensors for civil engineering applications”, different kinds of sensing techniques, including change of light intensity, interferometry, fiber Bragg grating, adsorption measurement and distributed sensing, are briefly reviewed to introduce the basic sensing principles. Then, the applications of OFS in highway structures, building structures, geotechnical structures, pipelines as well as cables monitoring are described, with focus on sensor design, installation technique and sensor performance. It is believed that the State-of-the-Art review is helpful to engineers considering the use of OFS in their projects, and can facilitate the wider application of OFS technologies in construction industry
TRIB2 as a biomarker for diagnosis and progression of melanoma
Malignant melanoma is the most deadly form of skin cancer. There is a critical need to identify the patients that could be successfully treated by surgery alone and those that require adjuvant treatment. In this study, we demonstrate that the expression of tribbles2 (TRIB2) strongly correlates with both the presence and progression of melanocyte-derived malignancies. We examined the expression of TRIB2 in addition to 12 previously described melanoma biomarkers across three independent full genome microarray studies. TRIB2 expression was consistently and significantly increased in benign nevi and melanoma, and was highest in samples from patients with metastatic melanoma. The expression profiles for the 12 biomarkers were poorly conserved throughout these studies with only TYR, S100B and SPP1 showing consistently elevated expression in metastatic melanoma versus normal skin. Strikingly we confirmed these findings in 20 freshly obtained primary melanoma tissue samples from metastatic lesions where the expression of these biomarkers were evaluated revealing that TRIB2 expression correlated with disease stage and clinical prognosis. Our results suggest that TRIB2 is a meaningful biomarker reflecting diagnosis and progression of melanoma, as well as predicting clinical response to chemotherapy.Fundacao para a Ciencia e a Tecnologia (FCT) [PEst-OE/EQB/LA0023/2012, SFRH/BPD/84634/2012, SFRH/BPD/70718/2010]info:eu-repo/semantics/publishedVersio
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