996 research outputs found

    Biologically Inspired Feedback Design for Drosophila Flight

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    We use a biologically motivated model of the Drosophila's flight mechanics and sensor processing to design a feedback control scheme to regulate forward flight. The model used for insect flight is the grand unified fly (GUF) [3] simulation consisting of rigid body kinematics, aerodynamic forces and moments, sensory systems, and a 3D environment model. We seek to design a control algorithm that will convert the sensory signals into proper wing beat commands to regulate forward flight. Modulating the wing beat frequency and mean stroke angle produces changes in the flight envelope. The sensory signals consist of estimates of rotational velocity from the haltere organs and translational velocity estimates from visual elementary motion detectors (EMD's) and matched retinal velocity filters. The controller is designed based on a longitudinal model of the flight dynamics. Feedforward commands are generated based on a desired forward velocity. The dynamics are linearized around this operating point and a feedback controller designed to correct deviations from the operating point. The control algorithm is implemented in the GUF simulator and achieves the desired tracking of the forward reference velocities and exhibits biologically realistic responses

    Critical appraisal of trastuzumab in treatment of advanced stomach cancer

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    Advanced or metastatic gastric cancer constitutes the majority of patients in clinical practice. In North America, about 70% of cases are advanced or metastatic when diagnosed, which is higher than the 50% reported in Japan. This difference in presentation is reflected in 5-year overall survival, which is about 20% in North America and 40%–60% in Japan. Despite numerous efforts of randomized studies on advanced gastric cancer, no globally accepted standard regimen has yet been established. Systemic chemotherapy provides palliation and prolongs survival, but the prognosis remains poor. Several monotherapies and combined regimens are currently available and vary around the world. Additionally, several molecular targeting agents are under evaluation in international randomized studies. Human epidermal growth factor receptor-2 (HER-2) is overexpressed or amplified in approximately 22% of patients with gastric cancer. Trastuzumab, a recombinant humanized anti-HER-2 monoclonal antibody, is the first biological therapy that has showed a survival improvement by nearly three months (reduced risk of death by 26%). Therefore, trastuzumab in combination with cisplatin is a reasonable treatment option for patients with advanced gastric cancer who are HER-2 positive. This paper will focus on trastuzumab, its chemical and pharmacological characteristics, and the relevant efficacy, safety, and tolerability studies

    1H-NMR urinary metabolomic profiling for diagnosis of gastric cancer

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    Background: Metabolomics has shown promise in gastric cancer (GC) detection. This research sought to identify whether GC has a unique urinary metabolomic profile compared with benign gastric disease (BN) and healthy (HE) patients. Methods: Urine from 43 GC, 40 BN, and 40 matched HE patients was analysed using 1H nuclear magnetic resonance (1H-NMR) spectroscopy, generating 77 reproducible metabolites (QC-RSD Results: GC displayed a clear discriminatory biomarker profile; the BN profile overlapped with GC and HE. LASSO-LR identified three discriminatory metabolites: 2-hydroxyisobutyrate, 3-indoxylsulfate, and alanine, which produced a discriminatory model with an area under the ROC of 0.95. Conclusions: GC patients have a distinct urinary metabolite profile. This study shows clinical potential for metabolic profiling for early GC diagnosis

    Potential of vascular endothelial growth factor as a biomarker of coronary artery disease in subjects undergoing CABG surgery

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    Introduction: • Coronary artery disease (CAD) causes local hypoxia due to reduced blood flow • Hypoxic conditions are known to induce vascular endothelial growth factor (VEGF) production, a key contributor to angiogenesis • The purpose of this study was to determine the potential of VEGF as a marker of myocardial stress in subjects with CAD undergoing coronary artery bypass grafting (CABG) surger

    Sarcopenic Obesity and Myosteatosis Are Associated with Higher Mortality in Patients with Cirrhosis

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    Background and aims Obesity is frequently associated with cirrhosis, and cirrhotic patients may develop simultaneous loss of skeletal muscle and gain of adipose tissue, culminating in the condition of sarcopenic obesity. Additionally, muscle depletion is characterized by both a reduction in muscle size and increased proportion of muscular fat, termed myosteatosis. In this study, we aimed to establish the frequency and clinical significance of sarcopenia, sarcopenic obesity and myosteatosis in cirrhotic patients. Methods We analysed 678 patients with cirrhosis. Sarcopenia, sarcopenic obesity and myosteatosis were analysed by CT scan using the third lumbar vertebrae skeletal muscle and attenuation indexes, using previously validated gender-and body mass index-specific cutoffs. Results Patients were predominately men (n = 457, 67%), and cirrhosis aetiology was hepatitis C virus in 269 patients (40%), alcohol in 153 (23%), non-alcoholic steatohepatitis/cryptogenic in 96 (14%), autoimmune liver disease in 55 (8%), hepatitis B virus in 43 (6%), and others in 5 patients (1%). Sarcopenia was present in 292 (43%), 135 had sarcopenic obesity (20%) and 353 had myosteatosis (52%). Patients with sarcopenia (22 ± 3 vs. 95 ± 22 months, P = 0.04) were associated with mortality. Conclusions Sarcopenia, sarcopenic obesity and myosteatosis are often present in patients with cirrhosis, and sarcopenia and myosteatosis are independently associated with a higher long-term mortality in cirrhosis

    An Erupting Classical Nova in a Globular Cluster of M87

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    Only one certain classical nova eruption has ever been detected inside a globular cluster - nova 1860 A.D. (T Sco) in M80. During a survey of M87 we have detected an erupting star coincident (to within 0.08 pixels) with a globular cluster of that giant elliptical galaxy. We are able to discount variables in the foreground or background of M87. The light curve and color of the erupting star match those expected for a nova at the distance of M87. The chance superposition of an M87 field nova on the globular cluster is very unlikely but cannot be completely ruled out.Our detection hints at a globular cluster nova frequency f.004f \sim .004 novae/cluster/year, much higher than previous observations have suggested

    The move beyond edutainment: have we learnt our lessons from the entertainment industry?

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    Serious games (SGs) have been used in the education of students and professionals for decades, but still have not reached their full potential, despite the large consensus they have gained recently. The entertainment game industry is a rapidly developing phenomenon, with a high market potential, enabled and enhanced by technological innovation. The question examined in this paper is: Did serious game designers learn from Entertainment Game (EG) designers in building a successful game? This paper presents three case study examples of games that have good learning outcomes to explore this question. This paper discusses the salient aspects and the differences between the examples and suggests how SGs could learn more from successful EGs

    The Globular Cluster M15. I. Identification, Discovery, and Period Determination of Variable Stars

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    We present new BVIBVI CCD photometry for variables in the globular cluster M15. Our photometry was obtained using both the image subtraction package ISIS and DAOPHOT/ALLFRAME. The data were acquired in 2001 on two observing runs on 11 observing nights using the 2-m telescope of the Bulgarian National Astronomical Observatory ``Rozhen'' with a Photometrics CCD camera. For 40 previously known variables, we present a period for the first time, and improved periods were obtained for many previously known variables. Fourteen new variables are reported. We present updated Bailey diagrams for the cluster and discuss its Oosterhoff classification. Although many of M15's RRab pulsators fall at an intermediate locus between Oosterhoff types I and II in the Bailey diagram, we argue that M15 is indeed a bona-fide Oosterhoff type IIComment: 48 pages, 7 figures, 3 table
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