33 research outputs found

    A semi-interactive panorama based 3D reconstruction framework for indoor scenes

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    We present a semi-interactive method for 3D reconstruction specialized for indoor scenes which combines computer vision techniques with efficient interaction. We use panoramas, popularly used for visualization of indoor scenes, but clearly not able to show depth, for their great field of view, as the starting point. Exploiting user defined knowledge, in term of a rough sketch of orthogonality and parallelism in scenes, we design smart interaction techniques to semi-automatically reconstruct a scene from coarse to fine level. The framework is flexible and efficient. Users can build a coarse walls-and-floor textured model in five mouse clicks, or a detailed model showing all furniture in a couple of minutes interaction. We show results of reconstruction on four different scenes. The accuracy of the reconstructed models is quite high, around 1% error at full room scale. Thus, our framework is a good choice for applications requiring accuracy as well as application requiring a 3D impression of the scene

    Building 3D Event Logs for Video Investigation

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    In scene investigation, creating a video log captured using a handheld camera is more convenient and more complete than taking photos and notes. By introducing video analysis and computer vision techniques, it is possible to build a spatio-temporal representation of the investigation. Such a representation gives a better overview than a set of photos and makes an investigation more accessible. We develop such methods and present an interface for navigating the result. The processing includes (i) segmenting a log into events using novel structure and motion features making the log easier to access in the time dimension, and (ii) mapping video frames to a 3D model of the scene so the log can be navigated in space. Our results show that, using our proposed features, we can recognize more than 70 percent of all frames correctly, and more importantly find all the events. From there we provide a method to semi-interactively map those events to a 3D model of the scene. With this we can map more than 80 percent of the events. The result is a 3D event log that captures the investigation and supports applications such as revisiting the scene, examining the investigation itself, or hypothesis testing

    Magnetic Dual Coupled Boost with Recovery Stage DC–HVDC Converter for Renewable Energy Generator-review under responsibility of the Euro-Mediterranean Institute for Sustainable Development (EUMISD)

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    International audienceThis paper presents a new high-efficiency-high-step-up based converter integrating two non-isolated secondary interleaved coupled inductors with recovery stages dedicated to smart HVDC distributed architecture in renewable energy production systems. Appropriate duty cycle ratio assumes that the two recovery stageswork with parallel charge and discharge to achieve high step-up voltage gain. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit and thus, low on-state resistance R dson of the main switch can be adopted to reduce conduction losses. In addition, the coupled inductors alleviate the reverse-recovery problem of the diode. Thus, the efficiencyof a basic DC-HVDC converter dedicated to renewable energy production can be further improved with such topology. A prototypeconverter is developed, and experimentallytested for validation

    Determination of low level nitrate/nitrite contamination using SERS-active Ag/ITO substrates coupled to a self-designed Raman spectroscopy system

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    A portable and simple Raman scattering and photoluminescence spectroscopy system was set up for sensitive and rapid determination of nitrate/nitrite at low concentrations in water samples. The SERS (Surface Enhanced Raman Scattering) – active Ag/ITO substrates were prepared and employed to obtain the enhanced Raman scattering light from the sample. Concentrations as low as 1 ppm and 0.1 ppm were detectable for nitrate and nitrite, respectively. The obtained results confirmed the usefulness of the designed system in actual environmental measurements and analysis

    Changes in the spike and nucleocapsid protein of porcine epidemic diarrhea virus strain in Vietnam—a molecular potential for the vaccine development?

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    Background Porcine epidemic diarrhea virus (PEDV) is a dangerous virus causing large piglet losses. PEDV spread rapidly between pig farms and caused the death of up to 90% of infected piglets. Current vaccines are only partially effective in providing immunity to suckling due to the rapid dissemination and ongoing evolution of PEDV. Methods In this study, the complete genome of a PEDV strain in Vietnam 2018 (IBT/VN/2018 strain) has been sequenced. The nucleotide sequence of each fragment was assembled to build a continuous complete sequence using the DNASTAR program. The complete nucleotide sequences and amino acid sequences of S, N, and ORF3 genes were aligned and analyzed to detect the mutations. Results The full-length genome was determined with 28,031 nucleotides in length which consisted of the 5′UTR, ORF1ab, S protein, ORF3, E protein, M protein, N protein, and 3′UTR region. The phylogenetic analysis showed that the IBT/VN/2018 strain was highly virulent belonged to the G2b subgroup along with the Northern American and Asian S-INDEL strains. Multiple sequence alignment of deduced amino acids revealed numerous mutations in the S, N, and ORF3 regions including one substitution 766P > L766 in the epitope SS6; two in the S0subdomain (135DN136 > 135SI136 and N144> D144); two in subdomain SHR1 at aa 1009L > M1009 and 1089S > L1089; one at aa 1279P > S1279 in subdomain SHR2 of the S protein; two at aa 364N > I364 and 378N > S378 in the N protein; four at aa 25L > S25, 70I > V70, 107C > F107, and 168D > N168 in the ORF3 protein. We identified two insertions (at aa 59NQGV62 and aa 145N) and one deletion (at aa 168DI169) in S protein. Remarkable, eight amino acid substitutions (294I > M294, 318A > S318, 335V > I335, 361A > T361, 497R > T497, 501SH502 > 501IY502, 506I > T506, 682V > I682, and 777P > L777) were found in SA subdomain. Besides, N- and O-glycosylation analysis of S, N, and ORF3 protein reveals three known sites (25G+, 123N+, and 62V+) and three novel sites (144D+, 1009M+, and 1279L+) in the IBT/VN/2018 strain compared with the vaccine strains. Taken together, the results showed that mutations in the S, N, and ORF3 genes can affect receptor specificity, viral pathogenicity, and the ability to evade the host immune system of the IBT/VN/2018 strain. Our results highlight the importance of molecular characterization of field strains of PEDV for the development of an effective vaccine to control PEDV infections in Vietnam

    Genome analysis and phylogenetic characterization of two deformed wing virus strains from Apis cerana in Vietnam

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    Background Deformed wing virus (DWV) is a virulent virus that causes honeybee disease. DWV can exist as a latent infection in honeybees, outbreak into epidemics, and cause serious damage to beekeeping cross the world, including Vietnam. Methods The two DWV strains circulating in Vietnamese honeybee, Apis cerana, were first isolated from adult honeybees in North Vietnam (DWV-NVN) and South Vietnam (DWV-SVN). Their complete nucleotide sequences were determined, aligned, and compared with other DWV strains. Results The two Vietnamese DWV strains comprised 10,113 bp and contained a large single open reading frame (ORF) of 2,893 amino acids, initiating at nucleotide 1,130 and terminating at nucleotide 9,812. Multiple nucleotide sequence alignment between these two DWV-VN strains and DWV strains in A. mellifera was performed. The DWV-VN strains showed a low genetic identity (from 91.4% to 92.0%) with almost of these strains, but lower identities (89.2% and 89.4%) with UK2 and (89.6%) with the China2 strain. Low identities (91.7% and 91.9%) were also observed between the China3 strain (in A. cerana) and the DWV-VN strains, respectively. The deduced amino acid sequence alignment showed high genetic similarities (97.0%–97.9%) when the USA1, Chile, Italy1, France, UK1, UK2, Japan, Korea2, China1, China2 and China3 strains were compared to the DWV-VN strains. This ratio was 96.7% and 96.8% when the Korea1 strain was compared to the DWV-SVN and DWV-NVN strains, respectively. Numerous amino acid substitutions were identified in the L, VP3, and RdRp sequences. Notably, we observed six substitutions positioned at amino acids 27 (E > I), 98 (S > T), 120 (A > V), 153 (M > T), 170 (D > F), and 174 (Y > F) in the L protein, two amino acid changes at positions 980 (S > A) and 1032 (E > T) in VP3, and one amino acid change at position 2627 (R > C) unique to the DWV-VN strains. Phylogenetic analysis based on complete genome sequences, RdRp sequences and Simplot analysis indicated that there was a significant difference between DWV-VN strains in A. cerana and DWV strains in A. mellifera. The results suggested that the genetic variations of the DWV-VN strains in A. cerana help them to adapt geographical conditions and may lead to change the viral pathogenicity of DWV-VN strains

    Advanced cell-based products generated via automated and manual manufacturing platforms under the quality by design principle: Are they equivalent or different?

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    Mesenchymal stem/stromal cells (MSCs) are multipotent stem cells that can be isolated from bone marrow, adipose tissue, the umbilical cord, dental pulp, etc. These cells have unique properties that give them excellent therapeutic potential, including immunoregulation, immunomodulation, and tissue regeneration functions. MSC-based products are considered advanced therapy medicinal products (ATMPs) under European regulations (1394/2007); thus, they must be manufactured under good manufacturing practices and via effective manufacturing methods. The former can be achieved via a proper laboratory design and compliance with manufacturing protocols, whereas the latter requires an approach that ensures that the quality of the products is consistent regardless of the manufacturing procedure. To meet these daunting requirements, this study proposes an exchangeable approach that combines optimized and equivalent manufacturing processes under the Quality by Design (QbD) principle, allowing investigators to convert from small laboratory-scale to large-scale manufacturing of MSC-based products for clinical applications without altering the quality and quantity of the cell-based products
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