448 research outputs found

    Hamilton - Jacobi treatment of front-form Schwinger model

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    The Hamilton-Jacobi formalism was applied to quantize the front-form Schwinger model. The importance of the surface term is discussed in detail. The BRST-anti-BRST symmetry was analyzed within Hamilton-Jacobi formalism.Comment: 11 pages, to be published in Int. Journ. Mod. Phys.

    Hamilton-Jacobi quantization of singular Lagrangians with linear velocities

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    In this paper, constrained Hamiltonian systems with linear velocities are investigated by using the Hamilton-Jacobi method. We shall consider the integrablity conditions on the equations of motion and the action function as well in order to obtain the path integral quantization of singular Lagrangians with linear velocities.Comment: late

    HoloPose: Holistic 3D Human Reconstruction In-The-Wild.

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    We introduce HoloPose, a method for holistic monocular 3D human body reconstruction. We first introduce a part-based model for 3D model parameter regression that allows our method to operate in-the-wild, gracefully handling severe occlusions and large pose variation. We further train a multi-task network comprising 2D, 3D and Dense Pose estimation to drive the 3D reconstruction task. For this we introduce an iterative refinement method that aligns the model-based 3D estimates of 2D/3D joint positions and DensePose with their image-based counterparts delivered by CNNs, achieving both model-based, global consistency and high spatial accuracy thanks to the bottom-up CNN processing. We validate our contributions on challenging benchmarks, showing that our method allows us to get both accurate joint and 3D surface estimates, while operating at more than 10fps in-the-wild. More information about our approach, including videos and demos is available at http://arielai.com/holopose

    Functional gold nanoparticle coated surfaces for CA 125 cancer biomarker detection

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    Here we describe the detailed characterization of gold nanoparticle (Au Np) functionalized surfaces as a biosensing platform by studying a model streptavidin (SA)-biotin interaction. Conjugation of SA on Au Np immobilized on silicon (Si) and quartz surfaces and its interaction with biotin were characterized by X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy, circular dichromism (CD) spectroscopy, and contact angle measurements. The immobilization method and atomic concentrations of Si 2p, Au 4f, S 2p, C 1s, N 1s, and O 1s of the resulting SA-biotin modified Si surface were determined by XPS. The CD spectrum and confocal microscopy imaging confirmed that step-by-step modification and bioconjugation can be monitored successfully. Such detailed and well-defined step-by-step characterization provides good information about the surface properties of biosensor platforms. In addition, the LSPR sensing ability of the Au Np based platforms was studied by using a model SA-biotin system. A 20 nm spectral red shift was detected when 150 nM SA was immobilized on to the Au Nps surface using the direct incubation/binding method on to the dry surface instead of the flow-injection method. The same platforms were also used to detect the CA 125 antibody-antigen system. Large spectral red shifts are very promising in terms of using these surfaces as LSPR biosensors. © TÜBİTAK

    Premarital screening of 466 Mediterranean women for serum ferritin, vitamin B12, and folate concentrations

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    Background/aim: Iron, folate, and vitamin B12 serum levels are closely related with dietary habits and have an essential role in the healthy development of a fetus. We aimed to investigate hemoglobin, ferritin, folate, and vitamin B12 levels in preconceptional women in an area where a plant-based diet referred to as Mediterranean cuisine is commonly used. Materials and methods: The study population included 466 women between the ages of 18 and 45 years admitted for thalassemia screening. Sociodemographic variables and history of menometrorrhagia, pica, and dietary habits were collected. Serum vitamin B12, folate, ferritin, and hemoglobin levels were measured. Ferritin of <12 μg/L, vitamin B12 of <200 pg/mL, and folate of <4 ng/mL were accepted as deficiencies. Hemoglobin level of <12 g/dL was classified as anemia. Results: Polymenorrhea was present in 11.7% and hypermenorrhea in 24.8% of women. Anemia was detected in 24.9% and thalassemia trait in 3.0% of women. Low ferritin levels were observed in 46.1%, vitamin B12 in 21.6%, and folate in 3.4% of women. In the group with low vitamin B12, decreased meat consumption was more prevalent (27.5% vs. 16.9%; P = 0.019). Conclusion: Vitamin B12 and iron are the main micronutrients depleted in our community. This necessitates implementing a public health program for women consuming a Mediterranean diet. © TÜBİTA

    Multi Hamilton-Jacobi quantization of O(3) nonlinear sigma model

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    The O(3) non-linear sigma model is investigated using multi Hamilton-Jacobi formalism. The integrability conditions are investigated and the results are in agreement with those obtained by Dirac's method. By choosing an adequate extension of phase space we describe the transformed system by a set of three Hamilton-Jacobi equations and calculate the corresponding action.Comment: 10 pages, LaTeX, to be published in Mod. Phys. Lett.

    Apical extrusion of debris using reciprocating files and rotary instrumentation systems

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    Background: To compare the preparation time and amount of apically extruded debris after the  preparation of root canals in extracted human teeth using the reciprocating files and rotary nickel.titanium systems.Procedure: Sixty extracted human mandibular premolars were used. The root canals were instrumented using reciprocating (WaveOne, Reciproc, SafeSider) or rotary motion (Typhoon, ProTaper Universal,  Mtwo), and the debris produced was collected in glass vials. The remaining debris was assessed using a microbalance and statistically analyzed using the one.way ANOVA and Duncan multiple range tests at a significance level of P &lt; 0.05. The time required to prepare the canals with different instruments was also recorded.Results: The Reciproc group produced significantly less debris when compared to the Typhoon group (P &lt; 0.05), and instrumentation with the single.file systems was significantly faster than in the multi.file systems (P &lt; 0.05). The WaveOne group extruded significantly more debris per unit of time than the other groups, with the exception of the Typhoon group (P &lt; 0.05).Conclusion: According to our study, all systems caused apical debris extrusion. However, the Reciproc group was associated with less debris extrusion when compared to the other groups.Key words: Apical extrusion, endodontics, single file system

    Weakly-supervised mesh-convolutional hand reconstruction in the wild

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    We introduce a simple and effective network architecture for monocular 3D hand pose estimation consisting of an image encoder followed by a mesh convolutional decoder that is trained through a direct 3D hand mesh reconstruction loss. We train our network by gathering a large-scale dataset of hand action in YouTube videos and use it as a source of weak supervision. Our weakly-supervised mesh convolutions-based system largely outperforms state-of-the-art methods, even halving the errors on the in the wild benchmark. The dataset and additional resources are available at https://arielai.com/mesh_hands

    BLSM: A Bone-Level Skinned Model of the Human Mesh

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    We introduce BLSM, a bone-level skinned model of the human body mesh where bone scales are set prior to template synthesis, rather than the common, inverse practice. BLSM first sets bone lengths and joint angles to specify the skeleton, then specifies identity-specific surface variation, and finally bundles them together through linear blend skinning. We design these steps by constraining the joint angles to respect the kinematic constraints of the human body and by using accurate mesh convolution-based networks to capture identity-specific surface variation. We provide quantitative results on the problem of reconstructing a collection of 3D human scans, and show that we obtain improvements in reconstruction accuracy when comparing to a SMPL-type baseline. Our decoupled bone and shape representation also allows for out-of-box integration with standard graphics packages like Unity, facilitating full-body AR effects and image-driven character animation. Additional results and demos are available from the project webpage: http://arielai.com/blsm

    The prophylactic efficacy of Anatolian propolis in individuals at high risk of COVID-19

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    OBJECTIVE: No prophylactic treatment is available for individuals at high risk of developing COVID-19. This study, which was conducted between December 25, 2020, and January 25, 2021, is one of the first clinical studies to evaluate the efficacy of Anatolian propolis supplement against COVID-19. The aim was to obtain evidence on the prophylactic use of Anatolian propolis in individuals at high risk of developing COVID-19. SUBJECTS AND METHODS: This volunteer-based study was conducted in two centers. The study involved 209 healthcare professionals (physicians, nurses, medical secretaries) from Emergency Medicine Department of Medical Faculty of Ataturk University and Emergency Medicine Department of Rize Recep Tayyip Erdogan University. 204 participants meeting the study criteria were divided into two groups as experimental group and control group. The experimental group received 20 drops of BEE’O UP (BEE&YOU) 30% Propolis drops twice a day during a follow-up period of 1 month. The control group received no supplement but was followed up. The participants showing symptoms during the study and all the participants at the end the study were subjected to PCR testing. RESULTS: The evaluation of the results of PCR testing at the end of the study has shown that 14 participants from the control group and only 2 participants from the experimental group, who received Anatolian propolis supplement, were reported as positive cases. CONCLUSIONS: It has been found that a statistically significant protection was induced against COVID-19 infection in 98% of the experimental group, who received Anatolian propolis, compared to the control group
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