1,296 research outputs found

    The Active Traveling Wave in the Cochlea

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    A sound stimulus entering the inner ear excites a deformation of the basilar membrane which travels along the cochlea towards the apex. It is well established that this wave-like disturbance is amplified by an active system. Recently, it has been proposed that the active system consists of a set of self-tuned critical oscillators which automatically operate at an oscillatory instability. Here, we show how the concepts of a traveling wave and of self-tuned critical oscillators can be combined to describe the nonlinear wave in the cochlea.Comment: 5 pages, 2 figure

    SWISSspine: a nationwide registry for health technology assessment of lumbar disc prostheses

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    SWISSspine is a so-called pragmatic trial for assessment of safety and efficiency of total disc arthroplasty (TDA). It follows the new health technology assessment (HTA) principle of "coverage with evidence development”. It is the first mandatory HTA registry of its kind in the history of Swiss orthopaedic surgery. Its goal is the generation of evidence for a decision by the Swiss federal office of health about reimbursement of the concerned technologies and treatments by the basic health insurance of Switzerland. During the time between March 2005 and 2008, 427 interventions with implantation of 497 lumbar total disc arthroplasties have been documented. Data was collected in a prospective, observational multicenter mode. The preliminary timeframe for the registry was 3years and has already been extended. Data collection happens pre- and perioperatively, at the 3months and 1-year follow-up and annually thereafter. Surgery, implant and follow-up case report forms are administered by spinal surgeons. Comorbidity questionnaires, NASS and EQ-5D forms are completed by the patients. Significant and clinically relevant reduction of low back pain VAS (70.3-29.4 points preop to 1-year postop, p<0.0001) leg pain VAS (55.5-19.1 points preop to 1-year postop, p<0.001), improvement of quality of life (EQ-5D, 0.32-0.73 points preop to 1-year postop, p<0.001) and reduction of pain killer consumption was revealed at the 1-year follow-up. There were 14 (3.9%) complications and 7 (2.0%) revisions within the same hospitalization reported for monosegmental TDA; there were 6 (8.6%) complications and 8 (11.4%) revisions for bisegmental surgery. There were 35 patients (9.8%) with complications during followup in monosegmental and 9 (12.9%) in bisegmental surgery and 11 (3.1%) revisions with new hospitalization in monosegmental and 1 (1.4%) in bisegmental surgery. Regression analysis suggested a preoperative VAS "threshold value” of about 44 points for increased likelihood of a minimum clinically relevant back pain improvement. In a short-term perspective, lumbar TDA appears as a relatively safe and efficient procedure concerning pain reduction and improvement of quality of life. Nevertheless, no prediction about the long-term goals of TDA can be made yet. The SWISSspine registry proofs to be an excellent tool for collection of observational data in a nationwide framework whereby advantages and deficits of its design must be considered. It can act as a model for similar projects in other health-care domain

    Effect of carbohydrate feeding on the bone metabolic response to running

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    Bone resorption is increased after running, with no change in bone formation. Feeding during exercise might attenuate this increase, preventing associated problems for bone. This study investigated the immediate and short-term bone metabolic responses to carbohydrate (CHO) feeding during treadmill running. Ten men completed two 7-day trials, once being fed CHO (8% glucose immediately before, every 20 min during, and immediately after exercise at a rate of 0.7 g CHO·kg body mass-1·h-1) and once being fed placebo (PBO). On day 4 of each trial, participants completed a 120-min treadmill run at 70% of maximal oxygen consumption (VO2 max). Blood was taken at baseline (BASE), immediately after exercise (EE), after 60 (R1) and 120 (R2) min of recovery, and on three follow-up days (FU1-FU3). Markers of bone resorption [COOH-terminal telopeptide region of collagen type 1 (β-CTX)] and formation [NH2-terminal propeptides of procollagen type 1 (P1NP)] were measured, along with osteocalcin (OC), parathyroid hormone (PTH), albumin-adjusted calcium (ACa), phosphate, glucagon-like peptide-2 (GLP-2), interleukin-6 (IL-6), insulin, cortisol, leptin, and osteoprotogerin (OPG). Area under the curve was calculated in terms of the immediate (BASE, EE, R1, and R2) and short-term (BASE, FU1, FU2, and FU3) responses to exercise. β-CTX, P1NP, and IL-6 responses to exercise were significantly lower in the immediate postexercise period with CHO feeding compared with PBO (β-CTX: P=0.028; P1NP: P=0.021; IL-6: P=0.036), although there was no difference in the short-term response (β-CTX: P=0.856; P1NP: P=0.721; IL-6: P=0.327). No other variable was significantly affected by CHO feeding during exercise. We conclude that CHO feeding during exercise attenuated the β-CTX and P1NP responses in the hours but not days following exercise, indicating an acute effect of CHO feeding on bone turnover

    Simple Classification of Light Baryons

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    We introduce a classification number nn which describes the baryon mass information in a fuzzy manner. According to nn and JpJ^p of baryons, we put all known light baryons in a simple table in which some baryons with same (nn, JpJ^p) are classified as members of known octets or decuplets. Meanwhile, we predict two new possible octets.Comment: 5 latex pages, 5 tables, no figur

    DOUBLE-TROUBLE: TAKOTSUBO AND ACUTE CORONARY SYNDROME IN A YOUNG WOMAN

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    Background: The original case series of patients with Takotsubo Syndrome (TTS) reported no significant epicardial coronary artery disease during angiography. However, recent evidence suggests an increasing overlap between the two diseases. We report a case of a 48-year old woman who had untreated generalized anxiety disorder and presented with angina. Case: A 48-year old woman with untreated general anxiety disorder presented with a 5 hour history of angina. An electrocardiogram demonstrated a prolonged QTc, no ST segment changes and new T-wave inversions in the anterolateral leads. High-sensitivity troponin was 4,336 ng/L and her InterTAK score was 91 with a 99.6% probability of TTS. Decision-making: Due to her persistent chest pain and EKG changes the patient underwent emergent left heart catheterization which showed critical occlusion of the 1st diagonal and 71% stenosis of the distal left circumflex. She underwent a primary PCI of both lesions. Her chest pain resolved after 6 hours of a nitrolgycerin infusion postoperatively and a transthoracic echocardiogram showed hypokinesis of the mid-distal apical, periapical, septal, lateral, inferior and anterior wall with an ejection fraction of 30-35%. The distribution of hypokinesia was out of proportion to the territory supplied by the culprit artery, suggesting a possibility of the apical type of Takotsubo syndrome. She was started on guideline-directed medical therapy for heart failure with reduced ejection fraction and dual antiplatelet therapy Conclusion: Patients with TTS may have coexistent significant epicardial CAD. Prolonged QTc and lack of ST-segment elevation in patients with CAD may help identify an additional diagnosis of TTS

    Quantitative study about the estimated impact of the AI Act

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    With the Proposal for a Regulation laying down harmonised rules on Artificial Intelligence (AI Act) the European Union provides the first regulatory document that applies to the entire complex of AI systems. While some fear that the regulation leaves too much room for interpretation and thus bring little benefit to society, others expect that the regulation is too restrictive and, thus, blocks progress and innovation, as well as hinders the economic success of companies within the EU. Without a systematic approach, it is difficult to assess how it will actually impact the AI landscape. In this paper, we suggest a systematic approach that we applied on the initial draft of the AI Act that has been released in April 2021. We went through several iterations of compiling the list of AI products and projects in and from Germany, which the Lernende Systeme platform lists, and then classified them according to the AI Act together with experts from the fields of computer science and law. Our study shows a need for more concrete formulation, since for some provisions it is often unclear whether they are applicable in a specific case or not. Apart from that, it turns out that only about 30\% of the AI systems considered would be regulated by the AI Act, the rest would be classified as low-risk. However, as the database is not representative, the results only provide a first assessment. The process presented can be applied to any collections, and also repeated when regulations are about to change. This allows fears of over- or under-regulation to be investigated before the regulations comes into effect.Comment: The raw data and the various categorizations (including the preprocessing steps) are submitted as wel

    Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy

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    The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer’s disease (AD) patients using the Multiscale Entropy (MSE). The MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant difference

    Isoscalar-isovector mass splittings in excited mesons

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    Mass splittings between the isovector and isoscalar members of meson nonets arise in part from hadronic loop diagrams which violate the Okubo-Zweig-Iizuka rule. Using a model for these loop processes which works qualitatively well in the established nonets, I tabulate predictions for the splittings and associated isoscalar mixing angles in the remaining nonets below about 2.5 GeV, and explain some of their systematic features. The results for excited vector mesons compare favorably with experiment.Comment: 8 RevTeX pages, including 1 LaTeX figure. CMU-HEP93-23/DOE-ER-40682-4

    Group U(6)×U(6) generated by current components

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    It has been suggested (1-3) that the equal-time commutation rules of the time components of the vector and axial-vector current octets (Fiα and Fiα5, respectively) are the same as if these currents had the simple form Giα and Giα5, defined as follows
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