238 research outputs found

    Thrombotic antiphospholipid syndrome: A practical guide to diagnosis and management

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    Thrombotic antiphospholipid syndrome (APS) is characterised by venous, arterial and/or small vessel thrombosis in the context of persistently positive antiphospholipid antibodies (aPL). The diagnosis and management of thrombotic APS continues to prove challenging for clinicians. We provide a practical guide to the diagnosis of APS including who to test for aPL and which tests to do. We also consider clinical practice points on the management of venous, arterial and small vessel thrombosis, in the context of first and recurrent thrombotic events. Non-criteria manifestations of APS are reviewed. An approach to recurrent thrombosis and anticoagulant-refractory APS is discussed, with options including increasing the anticoagulation intensity of vitamin K antagonists, switching to low-molecular-weight-heparin, the use of fondaparinux and/or the addition of antiplatelet treatment. Adjunctive options such as vitamin D, hydroxychloroquine and statins are also addressed

    Semi-classical buckling of stiff polymers

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    A quantitative theory of the buckling of a worm like chain based on a semi-classical approximation of the partition function is presented. The contribution of thermal fluctuations to the force-extension relation that allows to go beyond the classical Euler buckling is derived in the linear and non-linear regime as well. It is shown that the thermal fluctuations in the nonlinear buckling regime increase the end-to-end distance of the semiflexible rod if it is confined to 2 dimensions as opposed to the 3 dimensional case. Our approach allows a complete physical understanding of buckling in D=2 and in D=3 below and above the Euler transition.Comment: Revtex, 17 pages, 4 figure

    Modern Techniques for Memorizing Foreign Words

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    The article describes a comparative experiment studying the efficiency of five popular techniques which improve people's ability to memorize foreign words. The best results were achieved using two techniques: watching English movies with subtitles and writing letters in English

    Behavioral accounting theory in the scope of financial reporting and auditing applications

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    Psikoloji bilimi ile finansın kesişimi olarak nitelendirilebilecek olan davranışsal finans uzun yıllardır finans literatüründe yer almasına ve oldukça çok sayıda akademik çalışmaya konu olmasına rağmen davranışsal muhasebe bu bağlamda daha geride kalmıştır. Oysa ki Amerika Muhasebe Birliği’nin (AAA) muhasebe eğitiminde psikoloji ile ilgili konuları dahil etme yönündeki çağrısı 1970’li yıllara kadar geriye gitmektedir. Finansal raporları hazırlayan muhasebecilerin sıklıkla mesleki yargılarına göre karar vermek durumunda kalmaları ve raporların bu doğrultuda şekillenmesinin yanı sıra bu raporları denetleyenlerin mesleki şüphecilik ile hareket ediyor oluşu davranışsal muhasebenin etki alanını ortaya koymaktadır. Çalışmanın amacı davranışsal muhasebenin teorik altyapısını ve ilgili olduğu teorileri ortaya koymak ve finansal raporlama ve denetim uygulamalarındaki yansımalarını incelemektir. Bu doğrultuda ilgili finansal raporlama ve denetim standartları da ele alınmaktadır.Although behavioral finance, that can be described as the intersection of psychology and finance, has been in the financial literature for many years and is subject to a great number of academic studies, behavioral accounting has lagged behind in this context despite the call of the American Accounting Association (AAA) to include psychology-related issues in accounting education goes back to the 1970s. Accountants who prepare financial reports frequently make decisions according to professional judgment so they shape the financial reports accordingly; auditors of these reports are acted with professional skepticism. These two facts reveals the domain of behavioral accounting. The aim of the current study is to demonstrate the theoretical background of behavioral accounting and other theories linked and to examine the implications of financial reporting & auditing practices. In this respect, related financial reporting and auditing standards are also addressed.Publisher's Versio

    Competitive ability of <i>Escherichia coli</i> strains in the intestinal microbiota of patients with Crohn's disease and healthy volunteers: physiological, biochemical and genetic characteristics

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    Introduction. Crohn's disease (CD) is a chronic inflammation of various parts of the gastrointestinal tract with an increased proportion of Escherichia coli. However, the role of E. coli in disease remains unclear. This study aims to evaluate the competitive abilities of E. coli strains from CD patients and healthy volunteers, and to identify the biochemical and genetic determinants underlying these features. Materials and methods. The antagonistic activity was assessed by co-cultivation of 11 clinical E. coli strains inhibiting the growth of the K-12, with Enterobacter cloacae, Klebsiella pneumonia and Salmonella enterica. To elucidate the mechanism of antagonistic activity, the evaluation of biochemical properties and a comparative genomic analysis were used. Results and discussion. Genes of bacteriocin production systems were identified in genomes of 11 strains from CD patients and healthy volunteers active against the E. coli K-12 strain. Three strains from healthy individuals demonstrated activity against several Enterobacteriaceae bacteria. The strains biochemical properties were typical of representatives of E. coli. Strains 1_34_12, active against E. cloacae, and 1_45_11, inhibiting all tested enterobacteria, are phylogenetically related to the laboratory strain K-12. Strain 1_39_1, active against K. pneumonia and S. enterica, is phylogenetically close to the Nissle1917, contains the genes for colibactin biosynthesis and a variant of the fimH gene that increases the adhesive ability of bacteria. Conclusion. The identified E. coli strains are able to displace Enterobacteriaceae bacteria and can be used to study the bacteria-bacteria and host-bacteria interactions, to understand their role in gut homeostasis and intestinal inflammation

    Omics approaches in pancreatic adenocarcinoma

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    Pancreatic ductal adenocarcinoma, which represents 80% of pancreatic cancers, is mainly diagnosed when treatment with curative intent is not possible. Consequently, the overall five-year survival rate is extremely dismal—around 5% to 7%. In addition, pancreatic cancer is expected to become the second leading cause of cancer-related death by 2030. Therefore, advances in screening, prevention and treatment are urgently needed. Fortunately, a wide range of approaches could help shed light in this area. Beyond the use of cytological or histological samples focusing in diagnosis, a plethora of new approaches are currently being used for a deeper characterization of pancreatic ductal adenocarcinoma, including genetic, epigenetic, and/or proteo-transcriptomic techniques. Accordingly, the development of new analytical technologies using body fluids (blood, bile, urine, etc.) to analyze tumor derived molecules has become a priority in pancreatic ductal adenocarcinoma due to the hard accessibility to tumor samples. These types of technologies will lead us to improve the outcome of pancreatic ductal adenocarcinoma patients

    Viking Thrust Vector Control Dynamics Using Hybrid Coordinates to Model Vehicle Flexibility and Propellant Slosh

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    Control System Design Implementation of the linear feedback control system with time varying feedback gains and command forces may be accomplished with a fairly simple analog controller. The feedback gains and command forces consist of well behaved sinusoidal functions, constants, and simple ramp functions. The difficulty caused by the gain fluctuation near the simulation final time may be overcome by cycling the control gain functions back to the beginning before the fluctuations take place. Cycling the control gain functions is not a problem because the control is in a feedback form. The effect of cycling the control gain functions may be interpreted in the analysis as restarting the nonlinear simulation with an initial state closer to the final state. Simulation of the nonlinear system within the region of operation always resulted in a stable response so the effect of restarting the simulation when the system state has moved closer to the final state is valid. A consequence of cycling the control is that the functional in Eq. Conclusions This study has shown that the dynamic instability caused by sloshing fluid stores carried in the main rigid body of a spacecraft may be controlled by use of a linear quadratic regulator with the fluid modeled as an equivalent spherical pendulum and only the first mode of fluid oscillation included. The control system presented stabilized a highly nonlinear system for a large deviation from the nominal operating point and uses easily measured state variables (only main body fixed angular rates and attitude) and was shown to be stable for a wide variation in fluid level. It was shown that sensing the dynamic state of the fluid was not necessary for the specific spacecraft under study. A pointing maneuver was also successfully accomplished by this control system and a control design based on the analysis was outlined for the specific spacecraft. Acknowledgments This study was completed under partial support of contract no. AFOSR-86-0080 and subcontract 83RIP33, U.S. Air Force. The authors wish to acknowledge the support of Iowa State University in accomplishing the lengthy digital computer simulation required in this study. References Introduction An interesting problem in robotics is cloth handling. Applications include composite lay-up and apparel and upholstery manufacturing. Rebman (1986) describes an application of a tactile sensor to assembly of a flexible diaphram and a plastic cap. Hertzanu and Tabak (1986) described an adaptive controller for an industrial sewing machine. For most applications, cloth must be held taut and unwrinkled. It was postulated that this requires multi-axis force control, and a suitable control system was designed and constructed. The system chosen is an adaptive force feedback loop with position accommodation. Non-adaptive force feedback control schemes have been described and tested by many researchers, such as Whitney (1977). An adaptive force feedback loop for coordination of two robot arms was described by Because cloth stiffness varies depending on whether the individual cloth fibers are taut or slack, a nonadaptive loop is unsuitable for cloth handling. An adaptive control loop was designed with cloth stiffness as the adaptive variable. The system design was constructed and tested using a PUMA 560 robot with a LORD 15/50 force/torque sensor mounted on its wrist. Control System Description The parameter estimator is a least mean square (LMS) estimator. Let y=KH(z)u = K a x z &apos; + + a&quot;z~ -r-&quot;u, \+b x z + ... +b&quot;z~ where a it ..., a&quot; and b\ b&quot; axe found from the ordinary least squares plant identification, y is the error in the force, and u is the position command. Then the LMS estimator for A-is K* =K*^i+r{y-y*)w-l , where K* is the estimated stiffness, +a&quot;u&quot;&quot;), and Vf_ 1 =ff 1 «_ 1 + The position control law is where u, is the change in the position of the /th degree of freedom (DOF), y t is the force (or torque) error of the ith DOF, and K* is the stiffness of the rth DOF. end of a cloth of dimensions 36 by 36 in., the other end of which was attached to a table. Both ends of the cloth were stapled to wooden rods; proper robot end effectors would eliminate the need for these rods. Two 8086 microprocessor cards were also built. The 1st microprocessor calculated the cloth stiffness and end effector position changes; the 2nd microprocessor was used for communication with the robot and the force/torque sensor. Experimental Procedure The experiments were run with one end of the cloth fixed. The initial slack and misalignments of the cloth were as follows: Stretch (x) direction Lateral (y) direction 6 direction 6 to 10 in. of slack 2 to 4 in. of misalignment 5° to 20° of misalignment The robot straightened out the misalignments and pulled 4 lb of tension on the cloth. After it had done so the end effector was moved inward to produce 6 in. of slack in the x-direction. This movement draped the cloth over 2 boxes without wrinkling. Test Setup Experimental Results The visual results showed consistency between the experiments. In all of them, the cloth was successfully draped over the boxes without wrinkles, the motion was smooth, and the times were approximately the same. Transactions of the ASME position, the robot pulls a 4 lb tension on the cloth and adjusts the lateral (y) force and the moment to zero. This requires approximately 12 s. At 14 s the robot drapes the cloth; at this point the tension (x-force) falls to zero. This experiment was successfully repeated several times. Conclusions A force feedback control loop implemented on a robot has been used successfully to straighten and draw a tension on a cloth. Further work will include using more sophisticated end effectors to grip the cloth, and applications in upholstery and composite manufacture. Reference
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