438 research outputs found
A giant pancreatic pseudocyst in a patient with HIV infection.
No full textThis article describes the first case of a giant pancreatic pseudocyst in a 48-year-old man with HIV infection under combination antiretroviral therapy. The patient presented with an abdominal mass involving the epigastrium, left hypochondrium, and left flank. An enhanced abdominal computed tomography (CT) scan showed a well-defined cyst of 21 cm in diameter, with a liquid content that dislocated adjacent viscera. Microbiological and cytological tests on fluid were negative, confirming diagnosis of pancreatic pseudocyst. The CT-guided percutaneous drainage was carried out and the patient's clinical condition gradually improved. © The Author(s) 2012
GV and GW invariants via the enhanced movable cone
No full textGiven any smooth germ of a threefold flopping contraction, we first give a combinatorial characterisation of which Gopakumar-Vafa (GV) invariants are non-zero, by prescribing multiplicities to the walls in the movable cone. On the Gromov-Witten (GW) side, this allows us to describe, and even draw, the critical locus of the associated quantum potential. We prove that the critical locus is the infinite hyperplane arrangement of Iyama and the second author, and moreover that the quantum potential can be reconstructed from a finite fundamental domain. We then iterate, obtaining a combinatorial description of the matrix which controls the transformation of the non-zero GV invariants under a flop. There are three main ingredients and applications: (1) a construction of flops from simultaneous resolution via cosets, which describes how the dual graph changes, (2) a closed formula which describes the change in dimension of the contraction algebra under flop, and (3) a direct and explicit isomorphism between quantum cohomologies of different crepant resolutions, giving a Coxeter-style, visual proof of the Crepant Transformation Conjecture for isolated cDV singularities.32 pages. Comments welcome. v2: minor changes. Final version to appear in Modul
GV/cm scale laser-magnetic resonant acceleration in vacuum
No full textResonant acceleration of electrons by a laser in the background of an extra longitudinal magnetic field is investigated analytically and numerically. The resonant condition is independent of laser intensity, and when satisfied, the energy gain is proportional to a(0)(2) and the square of phase difference. This process is mainly limited by the magnitude and spatial size of the extra magnetic field. Under the laboratory conditions, simulation results show that a monoenergetic and collimated electron bunch can still be obtained in similar to GV/cm scale, which sheds a light on the vacuum table-top laser-driven electron accelerators.National Key Programme for S&TResearch and Development [2016YFA0401100]; China Academy of Engineering Physics Foundation [2014A0102003]SCI(E)ARTICLE3520-5273
On right K-completeness of the fine quasi-uniformity
No full text[EN] We investigate right K-components of the fine quasi-uniformity. It follows from our results the somewhat surprising fact that if (X,T) is a topological space condensable onto a quasi-metric space whose conjugate is Hausdorff, then any right K-Cauchy filter F on the fine quasi-uniformity of (X,T) is trivial (i.e. there is an x €X such that {x} generates F.The second author acknowledges the support of the Conselleria de Educació i Ciencia, Generalitat Valenciana, gran GV-2223/94Perez, M.; Romaguera, S. (1996). On right K-completeness of the fine quasi-uniformity. Questions and Answers in General Topology. 14(2):245-249. https://riunet.upv.es/handle/10251/107319S24524914
Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station
No full textKnowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law. © 2015 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the «http://creativecommons.org/licenses/by/3.0/» Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI
Photosynthesis down-regulation precedes carbohydrate accumulation under sink limitation in Citrus
No full textPhotosynthesis down-regulation due to an imbalance between sources and sinks in Citrus leaves could be mediated by excessive accumulation of carbohydrates. However, there is limited understanding of the physiological role of soluble and insoluble carbohydrates in photosynthesis regulation and the elements triggering the down-regulation process. In this work, the role of non-structural carbohydrates in the regulation of photosynthesis under a broad spectrum of source-sink relationships has been investigated in the Salustiana sweet orange. Soluble sugar and starch accumulation in leaves, induced by girdling experiments, did not induce down-regulation of the photosynthetic rate in the presence of sinks (fruits). The leaf-to-fruit ratio did not modulate photosynthesis but allocation of photoassimilates to the fruits. The lack of strong sink activity led to a decrease in the photosynthetic rate and starch accumulation in leaves. However, photosynthesis down-regulation due to an excess of total soluble sugars or starch was discarded because photosynthesis and stomatal conductance reduction occurred prior to any significant accumulation of these carbohydrates. Gas exchange and fluorescence parameters suggested biochemical limitations to photosynthesis. In addition, the expression of carbon metabolism-related genes was altered within 24 h when strong sinks were removed. Sucrose synthesis and export genes were inhibited, whereas the expression of ADP-glucose pyrophosphorylase was increased to cope with the excess of assimilates. In conclusion, changes in starch and soluble sugar turnover, but not sugar content per se, could provide the signal for photosynthesis regulation. In these conditions, non-stomatal limitations strongly inhibited the photosynthetic rate prior to any significant increase in carbohydrate levels. © The Author 2011. Published by Oxford University Press. All rights reserved.This work was supported by the Conselleria de Cultura, Educacio i Esport de la Generalitat Valenciana [GV/2007/213 and GV/2009/034].González Nebauer, S.; Renau Morata, B.; Guardiola, JL.; Molina Romero, RV. (2011). Photosynthesis down-regulation precedes carbohydrate accumulation under sink limitation in Citrus. Tree Physiology. 31(2):169-177. doi:10.1093/treephys/tpq103S16917731
TUD-GV Dataset for Floating Litter Detection
No full text<p>This dataset contains the data used for the publication of "Jia T, Vallendar AJ, de Vries R, Kapelan Z and Taormina R (2023) Advancing deep learning-based detection of floating litter using a novel open dataset. <i>Front. Water</i> 5:1298465. doi: 10.3389/frwa.2023.1298465"</p><p>The large-scale "TU Delft - Green Village" (TUD-GV) dataset is for detecting floating litter with computer vision. We created this dataset from experiments conducted during 10 days in February and April 2021 in a small drainage canal at The Green Village — a field lab facility in the TU Delft Campus, the Netherlands. We captured data using two action cameras (GoPro HERO4 and GoPro MAX 360) and a phone (Huawei P30 Pro) mounted on four different locations on a bridge. All devices recorded videos with a resolution of 1080p, a linear field of view, and a FPS (frame per second) of 24 (for the action cameras) or 30 (for the phone).</p><p>This dataset consists of 9,473 RGB images. We manually labeled the images in the TUD-GV dataset into four classes: <i>no litter</i> (0 items), <i>little litter</i> (1-2 items), <i>moderate litter</i> (3-5 items), and <i>lots of litter</i> (6-10 items) according to the number of litter items in images.</p><p>This dataset is stored in the ZIP file contain 77 directories and the TUD-GV.xls file. Each of these directories contain four class label directories, and each label directory contains JPG images. The TUD-GV.xls file contains the detailed information of images in 77 directories, including collecting date, collecting time, device, device location (in a bridge), device degree, device height, weather conditions, litter source, the number of images per class, and the number of images in total.</p><p>If you use this dataset for a publication, please cite the paper. Here is a BibTeX entry:</p><p>@article{jia2023advancing,
title={Advancing Deep Learning-based Detection of Floating Litter using a Novel Open Dataset},
author={Jia, Tianlong and Vallendar, Andre Jehan and de Vries, Rinze and Kapelan, Zoran and Taormina, Riccardo},
journal={Frontiers in Water},
volume={5},
pages={1298465},
publisher={Frontiers},
year={2023}
}</p>
Funções e princípios justificadores da responsabilidade civil e o art. 927, § único do Código Civil
No full textThis paper has the goal to reflect upon possible guidelines for the interpretation of art. 927, parágrafo único, of the new Brazilian civil code, which has introduced a general strict tort liability rule into Brazilian law. In order to do that, the author analyzes the functions normally attributed do tort liability, as well as the principles developed to justify strict liability in general.O presente artigo tem como objetivo refletir sobre possíveis parâmetros para a interpretação do art. 927, parágrafo único, do cc – que introduziu no direito brasileiro uma norma geral de responsabilidade objetiva – com base nas funções normalmente atribuídas à responsabilidade e nos princípios desenvolvidos pela doutrina para justificar a imputação de responsabilidade sem culpa
Il Signore Risorto – la Gioia del Vangelo (GV 20, 20b)
No full textThe author analyses exegetically J 20, 19–20 where the disciples were filled with joy when they saw Risen Jesus. Starting from the analysis of the literary context and the motives related to the disciples’ joy, the author stresses church-centered role of the Risen Lord (kyrios). He points out a number of references to the appearances of Risen Christ in Luke 24, which seem to have many points in common with the Johannine tradition. He particularly focuses on the very moment of appearance when Jesus in a symbolic gesture shows his hands and side to the disciples. The hands and side are the symbols of tender love of the Good Shepherd and inexhaustible source of the Holy Spirit. Moreover, he presents the contrast between the experience of fear, confusion and scattering (before the Resurrection) and the experience of joy, confidence and unity which was rediscovered around the Risen Jesus.L’articolo presenta un’analisi esegetica di Gv 20, 19–20, dove gli apostoli si rallegrarono al vedere Gesù risorto. Si esamina il contesto letterario, i motivi inerenti alla gioia dei discepoli e il ruolo ecclesiocentrico del Signore Risorto (kyrios). Non mancano riferimenti al racconto delle apparizioni in Lc 24, che sembra molto vicino alla tradizione giovannea. Un’attenzione particolare viene data al momento dell’apparizione, quando Gesù, eseguendo un gesto simbolico, mostra ai discepoli le mani e il costato, entrambi i simboli della amorevole cura del Buon Pastore e dell’inesauribile fonte dello Spirito Santo. Inoltre, viene messo in risalto il contrasto tra lo stato di paura, smarrimento e dispersione (prima dell’apparizione del Risorto) e lo stato di gioia, fiducia e ritrovata unità attorno a Gesù Risorto
Engineering of protein-based phononic crystals for contrast-enhanced ultrasound imaging
No full textContrast-enhanced ultrasound (CEUS) imaging is one of the most widely used biomedical imaging modalities in clinical practice due to its high spatiotemporal resolution and non-invasiveness. However, CEUS imaging techniques rely heavily on microbubble contrast agents that add significant random fluctuations to ultrasound signals and have a limited imaging time. Gas vesicles (GVs), a unique class of stable, air-filled protein nanostructures, have recently been introduced as genetically encoded acoustic contrast agents. While being capable of withstanding higher acoustic pressures and providing smoother hemodynamic ultrasound signals than microbubbles, GVs show a lower ultrasound signal enhancement than microbubbles and are taken up by the liver. The only known solution to enhance ultrasound scattering by GVs, or GV echogenicity, is through GV aggregation. Specifically, periodic aggregation could theoretically maximize contrast since phononic crystals, periodic configurations of air-filled inclusions, are known to significantly amplify sound wave reflections at specific frequencies. Meanwhile, many strategies currently exist in biomedical research to improve biocompatibility. Most interesting is the microfluidic encapsulation in alginate beads, as alginate hydrogels significantly prolong the circulation time of encapsulates while microfluidics offers a high-throughput fabrication method with great control and reproducibility. In this thesis, a first step is presented towards novel GV-based ultrasound contrast agents with enhanced echogenicity and prolonged circulation times. Using a highthroughput microfluidic approach, periodically aggregated GVs are encapsulated in alginate hydrogel beads. In order to obtain these novel GV-based ultrasound contrast agents, the contrast enhancement of several GV aggregation strategies, including depletion interactions, fusion proteins and ionic screening, was first investigated. A four-fold increase in nonlinear ultrasound contrast was found for alginate-induced periodic GV aggregation, compared to a two-fold increase for randomly aggregated GVs. This contrast enhancement was found to arise at a concentration of 1.25 mg/ml of alginate. Moreover, a high-throughput droplet-based microfluidic approach was used to encapsulate GVs in ∼245 micron beads at a rate of 600 beads per second. Phase contrast microscopy demonstrated the successful encapsulation of GVs, while empty and GV-filled alginate beads both appeared in ultrasound imaging, likely due to entrapped air. In future work, more advanced microfluidic encapsulation can be explored to fabricate smaller, micron-scale alginate beads without unwanted air-filled cavities. Once successful, and prolonged circulation times have been proven in animal studies, these novel ultrasound contrast agents with improved properties can become the go-to contrast agents for various CEUS applications, including transcranial functional ultrasound imaging.Biomedical Engineering | Nanobiolog
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