29 results on '"L. Silva"'
Search Results
2. Random lasing and replica symmetry breaking in GeO2-PbO-MgO glass–ceramics doped with neodymium
- Author
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Josivanir G. Câmara, Davinson M. da Silva, Luciana R. P. Kassab, Manoel L. Silva-Neto, Guillermo Palacios, and Cid B. de Araújo
- Subjects
Multidisciplinary - Abstract
We investigated the random lasing process and Replica Symmetry Breaking (RSB) phenomenon in neodymium ions (Nd3+) doped lead-germanate glass–ceramics (GCs) containing MgO. Glass samples were fabricated by conventional melt-quenching technique and the GCs were obtained by carefully devitrifying the parent glasses at 830 °C for different time intervals. The partial crystallization of the parent glasses was verified by X-ray diffraction. Photoluminescence (PL) enhancement of $$\approx$$ ≈ 500% relative to the parent glasses was observed for samples with a higher crystallinity degree (annealed during 5 h). Powders with grains having average size of 2 µm were prepared by griding the GCs samples. The Random Laser (RL) was excited at 808 nm, in resonance with the Nd3+ transition 4I9/2 → {4F5/2, 2H9/2}, and emitted at 1068 nm (transition 4F3/2 → 4I11/2). The RL performance was clearly enhanced for the sample with the highest crystallinity degree whose energy fluence excitation threshold (EFEth) was 0.25 mJ/mm2. The enhanced performance is attributed to the residence-time growth of photons inside the sample and the higher quantum efficiency of Nd3+ incorporated within the microcrystals, where radiative losses are reduced. Moreover, the phenomenon of Replica Symmetry Breaking (RSB), characteristic of a photonic-phase-transition, was detected by measuring the intensity fluctuations of the RL emission. The Parisi overlap parameter was determined for all samples, for excitation below and above the EFEth. This is the first time, for the best of the authors knowledge, that RL emission and RSB are reported for a glass–ceramic system.
- Published
- 2022
3. Author Correction: An emotional discrete controller PSO tuned and designed for a real industrial pumping system
- Author
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Davidson C. Marques, Jeydson L. Silva, Milde Maria S. Lira, and Ronaldo R. B. Aquino
- Subjects
Multidisciplinary - Published
- 2022
4. An emotional discrete controller PSO tuned and designed for a real industrial pumping system
- Author
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Davidson C. Marques, Jeydson L. Silva, Milde Maria S. Lira, and Ronaldo R. B. Aquino
- Subjects
Physical Phenomena ,Automation ,Multidisciplinary ,Logic ,Industry ,Algorithms - Abstract
The application of automation techniques to water pump systems, combined with modern control techniques, has been increasing the hydraulic and energy efficiency of such systems. In this context, the objective of this work is to present an intelligent method of flow control based on Brain Emotional Learning Basic Intelligent Control (BELBIC), which will be applied to an experimental workbench of a pumping system, located in the Energy Efficiency and Energy Quality Laboratory (LEEQE) at Federal University of Pernambuco (UFPE). The parameters of this controller are optimized with a particle swarm optimization (PSO) technique with minimization of Integral Absolute Error (IAE). Initial tests were performed in a computational environment so that the system’s performance could be pre-tested, thereby the dynamics of the system was modeled from real data generated in the process. The experimental results were obtained through the implementation of this control system in a programmable logic controller (PLC), which was the device responsible for all the automation of the workbench previously mentioned. The data of this workbench were collected using a supervisory system exclusively developed for this work. These data were then used to analyze the performance of the proposed control system, which demonstrated that its behavior was efficient.
- Published
- 2021
5. RNA modulates aggregation of the recombinant mammalian prion protein by direct interaction
- Author
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Petar Stefanov Kovachev, Natália Ferreira, Mariana Pierre de Barros Gomes, Suparna Sanyal, Luciana P. Rangel, Leticia P. Felix Valadão, Lucas M. Ascari, Yraima Cordeiro, and Jerson L. Silva
- Subjects
0301 basic medicine ,Circular dichroism ,Prions ,RNase P ,lcsh:Medicine ,Protein aggregation ,Article ,Prion Proteins ,Cofactor ,law.invention ,Mice ,Protein Aggregates ,03 medical and health sciences ,Ribonucleases ,0302 clinical medicine ,Dynamic light scattering ,law ,Animals ,RNA, Messenger ,lcsh:Science ,Multidisciplinary ,biology ,Chemistry ,lcsh:R ,Biochemistry and Molecular Biology ,RNA ,Dynamic Light Scattering ,Recombinant Proteins ,Kinetics ,030104 developmental biology ,RNA, Ribosomal ,Recombinant DNA ,Nucleic acid ,biology.protein ,Biophysics ,lcsh:Q ,Biokemi och molekylärbiologi ,030217 neurology & neurosurgery - Abstract
Recent studies have proposed that nucleic acids act as potential cofactors for protein aggregation and prionogenesis. By means of sedimentation, transmission electron microscopy, circular dichroism, static and dynamic light scattering, we have studied how RNA can influence the aggregation of the murine recombinant prion protein (rPrP). We find that RNA, independent of its sequence, source and size, modulates rPrP aggregation in a bimodal fashion, affecting both the extent and the rate of rPrP aggregation in a concentration dependent manner. Analogous to RNA-induced liquid-liquid phase transitions observed for other proteins implicated in neurodegenerative diseases, high protein to RNA ratios stimulate rPrP aggregation, while low ratios suppress it. However, the latter scenario also promotes formation of soluble oligomeric aggregates capable of seeding de novo rPrP aggregation. Furthermore, RNA co-aggregates with rPrP and thereby gains partial protection from RNase digestion. Our results also indicate that rPrP interacts with the RNAs with its N-terminus. In summary, this study elucidates the proposed adjuvant role of RNA in prion protein aggregation and propagation, and thus advocates an auxiliary role of the nucleic acids in protein aggregation in general. Manuscript title: Direct involvement of RNA in mammalian prion protein aggregation: Involvement of RNA in rPrP aggregation
- Published
- 2019
6. Microscopy analysis of Zika virus morphogenesis in mammalian cells
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Renata Campos Azevedo, Lucio Ayres Caldas, Jerson L. Silva, and Wanderley de Souza
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0301 basic medicine ,Cell type ,Electron Microscope Tomography ,viruses ,030106 microbiology ,lcsh:Medicine ,Biology ,Virus Replication ,Arbovirus ,Virus ,Article ,Zika virus ,Cell Line ,03 medical and health sciences ,Flaviviridae ,Aedes ,Chlorocebus aethiops ,medicine ,Morphogenesis ,Animals ,Humans ,Vector (molecular biology) ,Super-resolution microscopy ,lcsh:Science ,Tropism ,Virus Release ,Multidisciplinary ,Host Microbial Interactions ,Zika Virus Infection ,lcsh:R ,Epithelial Cells ,Zika Virus ,medicine.disease ,biology.organism_classification ,Virology ,Macaca mulatta ,Flavivirus ,030104 developmental biology ,Microscopy, Fluorescence ,lcsh:Q ,Infection - Abstract
Zika virus (ZIKV) is an arbovirus that recently emerged in the Americas as an important pathogen mainly because of its expanded pathogenesis, and elevated tropism for neuronal cells, transposition across the placental barrier, and replication in reproductive tract cells. Thus, transmission modes are eventually independent of an invertebrate vector, which is an atypical behavior for the flavivirus genus and indicates the need to study the replication of this virus in different cell types. Although ZIKV became a target for public health programs, the interaction of this flavivirus with the infected cell is still poorly understood. Herein, we analyzed the main stages of virus morphogenesis in mammalian cells, from establishment of the viroplasm-like zone to viral release from infected cells, using super-resolution fluorescence microscopy and electron microscopy. In addition, we compared this with other host cell types and other members of the Flaviviridae family that present a similar dynamic.
- Published
- 2020
7. Increase in fatty acids and flotillins upon resveratrol treatment of human breast cancer cells
- Author
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Georgia C. Atella, Marcos Henrique Ferreira Sorgine, Claudia Mermelstein, Luciana Gomes, Christian Ferreira, Jerson L. Silva, Carlos Luan Alves Passos, Ivone Rosa de Andrade, and Eliane Fialho
- Subjects
Cell Survival ,lcsh:Medicine ,Breast Neoplasms ,Cellular imaging ,Resveratrol ,Article ,Antioxidants ,chemistry.chemical_compound ,Breast cancer ,Membrane Microdomains ,medicine ,Humans ,Distribution (pharmacology) ,lcsh:Science ,skin and connective tissue diseases ,Lipid raft ,Multidisciplinary ,Chemistry ,Cell Membrane ,Fatty Acids ,lcsh:R ,Membrane Proteins ,medicine.disease ,Cell culture ,Polyphenol ,Cancer cell ,MCF-7 Cells ,Cancer research ,lcsh:Q ,Human breast - Abstract
Flotillin-1 and flotillin-2 are highly conserved proteins that localize into cholesterol-rich microdomains in cellular membranes. Flotillins are closely related to the occurrence and development of various types of human cancers. Flotillin-1 is highly expressed in breast cancer, and the high expression level of flotillin-1 is significantly correlated with poorer patient survival. Here we studied the relationship between the formation of lipid rafts and the expression of flotillins and lipids in human breast cancer cells. We used the polyphenol compound resveratrol to alter the structure and function of the plasma membrane. Our data revealed an increase in fatty acids in MCF-7 and MDA-MB-231 cells upon resveratrol treatment. Interestingly, we also found an increase in the expression of both flotillin-1 and flotillin-2 in breast tumor cells after treatment. Resveratrol also induced changes in the pattern of flotillin distribution among detergent-resistant lipid rafts fractions in both cell lines and induced the nuclear translocation of flotillin-2. Since resveratrol has been pointed out as a putative cancer therapy agent, our results could have an impact on the understanding of the effects of resveratrol in tumor cells.
- Published
- 2019
8. Author Correction: The dynamics of plant nutation
- Author
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Vicente Raja, Roghaieh Holghoomi, Paula L. Silva, and Paco Calvo
- Subjects
Multidisciplinary ,Computer science ,Nutation ,Science ,Dynamics (mechanics) ,Medicine ,Statistical physics - Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
- Published
- 2021
9. Apocynin and Nox2 regulate NF-κB by modifying thioredoxin-1 redox-state
- Author
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Min Zhang, Célio Xavier dos Santos, Aleksandar Ivetic, John Stephen Hothersall, Rui Curi, Fernando Q. Cunha, Cristoforo Scavone, Maria-Célia Cervi, Raphael Gomes Ferreira, José C. Alves-Filho, Rangel L. Silva, Silvia Cellone Trevelin, Lucia Rossetti Lopes, Pérsio Roxo-Junior, Francisco R.M. Laurindo, Ajay M. Shah, Larissa de Sá Lima, Andrew M. Cobb, and Thiago M. Cunha
- Subjects
Lipopolysaccharides ,Male ,0301 basic medicine ,animal structures ,Auranofin ,Pharmacology ,Granulomatous Disease, Chronic ,Article ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Thioredoxins ,0302 clinical medicine ,Chronic granulomatous disease ,Sepsis ,medicine ,Animals ,Mice, Knockout ,Multidisciplinary ,ESTRESSE OXIDATIVO ,NF-kappa B ,Acetophenones ,NF-κB ,NFKB1 ,medicine.disease ,3. Good health ,030104 developmental biology ,chemistry ,NADPH Oxidase 2 ,Apocynin ,Tumor necrosis factor alpha ,Signal transduction ,Thioredoxin ,Oxidation-Reduction ,030217 neurology & neurosurgery ,Signal Transduction ,medicine.drug - Abstract
The reactive-oxygen-species-(ROS)-generating-enzyme Nox2 is essential for leukocyte anti-microbial activity. However its role in cellular redox homeostasis and, consequently, in modulating intracellular signaling pathways remains unclear. Herein, we show Nox2 activation favors thioredoxin-1 (TRX-1)/p40phox interaction, which leads to exclusion of TRX-1 from the nucleus. In contrast, the genetic deficiency of Nox2 or its pharmacological inhibition with apocynin (APO) results in reductive stress after lipopolysaccharide-(LPS)-cell stimulation, which causes nuclear accumulation of TRX-1 and enhanced transcription of inflammatory mediators through nuclear-factor-(NF)-κB. The NF-κB overactivation is prevented by TRX-1 oxidation using inhibitors of thioredoxin reductase-1 (TrxR-1). The Nox2/TRX-1/NF-κB intracellular signaling pathway is involved in the pathophysiology of chronic granulomatous disease (CGD) and sepsis. In fact, TrxR-1 inhibition prevents nuclear accumulation of TRX-1 and LPS-stimulated hyperproduction of tumor-necrosis-factor-(TNF)-α by monocytes and neutrophils purified from blood of CGD patients, who have deficient Nox2 activity. TrxR-1 inhibitors, either lanthanum chloride (LaCl3) or auranofin (AUR), also increase survival rates of mice undergoing cecal-ligation-and-puncture-(CLP). Therefore, our results identify a hitherto unrecognized Nox2-mediated intracellular signaling pathway that contributes to hyperinflammation in CGD and in septic patients. Additionally, we suggest that TrxR-1 inhibitors could be potential drugs to treat patients with sepsis, particularly in those with CGD.
- Published
- 2016
- Full Text
- View/download PDF
10. Amide hydrogens reveal a temperature-dependent structural transition that enhances site-II Ca
- Author
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Tiago, Veltri, Guilherme A P, de Oliveira, Ewa A, Bienkiewicz, Fernando L, Palhano, Mayra de A, Marques, Adolfo H, Moraes, Jerson L, Silva, Martha M, Sorenson, and Jose R, Pinto
- Subjects
Models, Molecular ,Binding Sites ,Magnetic Resonance Spectroscopy ,Circular Dichroism ,Molecular Conformation ,Temperature ,Hydrogen Bonding ,Amides ,Article ,Kinetics ,Structure-Activity Relationship ,Amino Acid Substitution ,Mutation ,Humans ,Thermodynamics ,Calcium ,Protein Interaction Domains and Motifs ,Troponin C ,Hydrophobic and Hydrophilic Interactions ,Alleles ,Hydrogen ,Protein Binding - Abstract
The hypertrophic cardiomyopathy-associated mutant D145E, in cardiac troponin C (cTnC) C-domain, causes generalised instability at multiple sites in the isolated protein. As a result, structure and function of the mutant are more susceptible to higher temperatures. Above 25 °C there are large, progressive increases in N-domain Ca2+-binding affinity for D145E but only small changes for the wild-type protein. NMR-derived backbone amide temperature coefficients for many residues show a sharp transition above 30–40 °C, indicating a temperature-dependent conformational change that is most prominent around the mutated EF-hand IV, as well as throughout the C-domain. Smaller, isolated changes occur in the N-domain. Cardiac skinned fibres reconstituted with D145E are more sensitive to Ca2+ than fibres reconstituted with wild-type, and this defect is amplified near body-temperature. We speculate that the D145E mutation destabilises the native conformation of EF-hand IV, leading to a transient unfolding and dissociation of helix H that becomes more prominent at higher temperatures. This creates exposed hydrophobic surfaces that may be capable of binding unnaturally to a variety of targets, possibly including the N-domain of cTnC when it is in its open Ca2+-saturated state. This would constitute a potential route for propagating signals from one end of TnC to the other.
- Published
- 2016
11. Molecular Structure – Optical Property Relationships for a Series of Non-Centrosymmetric Two-photon Absorbing Push-Pull Triarylamine Molecules
- Author
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Leonardo De Boni, Wojciech Bartkowiak, Marcelo G. Vivas, Jérémy Malinge, Hans Ågren, Sylvio Canuto, Robert Zaleśny, Eléna Ishow, Mohammed Boujtita, Cleber Renato Mendonça, Daniel L. Silva, Instituto de Física de São Carlos (IFSC-USP), Universidade de São Paulo (USP), Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires (PPSM), École normale supérieure - Cachan (ENS Cachan)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation (CEISAM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Wroclaw University of Science and Technology, Theoretical Chemistry, Royal Institute of Technology [Stockholm] (KTH ), Núcleo de Análise de Resíduos de Pesticidas (NARP), and Universidade Federal do Maranhão [São Luis] (UFMA)
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Optics and Photonics ,Photon ,Materials science ,Electrons ,02 engineering and technology ,Electron ,010402 general chemistry ,01 natural sciences ,Molecular physics ,Article ,Absorption ,Structure-Activity Relationship ,chemistry.chemical_compound ,Absorptiometry, Photon ,[CHIM]Chemical Sciences ,Molecule ,Electronic band structure ,Absorption (electromagnetic radiation) ,Fluorescent Dyes ,Photons ,Multidisciplinary ,Trifluoromethyl ,Molecular Structure ,Diphenylamine ,ABSORÇÃO DA LUZ ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Dipole ,chemistry ,Femtosecond ,0210 nano-technology - Abstract
This article reports on a comprehensive study of the two-photon absorption (2PA) properties of six novel push-pull octupolar triarylamine compounds as a function of the nature of the electron-withdrawing groups. These compounds present an octupolar structure consisting of a triarylamine core bearing two 3,3′-bis(trifluoromethyl)phenyl arms and a third group with varying electron-withdrawing strength (H < CN < CHO < NO2 < Cyet < Vin). The 2PA cross-sections, measured by using the femtosecond open-aperture Z-scan technique, showed significant enhancement from 45 up to 125 GM for the lowest energy band and from 95 up to 270 GM for the highest energy band. The results were elucidated based on the large changes in the transition and permanent dipole moments and in terms of (i) EWG strength, (ii) degree of donor-acceptor charge transfer and (iii) electronic coupling between the arms. The 2PA results were eventually supported and confronted with theoretical DFT calculations of the two-photon transition oscillator strengths.
- Published
- 2014
12. Fragmented imaginary-time evolution for early-stage quantum signal processors
- Author
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Thais L. Silva, Márcio M. Taddei, Stefano Carrazza, and Leandro Aolita
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Medicine ,Science - Abstract
Abstract Simulating quantum imaginary-time evolution (QITE) is a significant promise of quantum computation. However, the known algorithms are either probabilistic (repeat until success) with unpractically small success probabilities or coherent (quantum amplitude amplification) with circuit depths and ancillary-qubit numbers unrealistically large in the mid-term. Our main contribution is a new generation of deterministic, high-precision QITE algorithms that are significantly more amenable experimentally. A surprisingly simple idea is behind them: partitioning the evolution into a sequence of fragments that are run probabilistically. It causes a considerable reduction in wasted circuit depth every time a run fails. Remarkably, the resulting overall runtime is asymptotically better than in coherent approaches, and the hardware requirements are even milder than in probabilistic ones. Our findings are especially relevant for the early fault-tolerance stages of quantum hardware.
- Published
- 2023
- Full Text
- View/download PDF
13. Brazilian Amazon indigenous territories under deforestation pressure
- Author
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Celso H. L. Silva-Junior, Fabrício B. Silva, Barbara Maisonnave Arisi, Guilherme Mataveli, Ana C. M. Pessôa, Nathália S. Carvalho, João B. C. Reis, Admo R. Silva Júnior, Nathalia A. C. S. Motta, Paulo Vinícius Moreira e Silva, Francarlos Diniz Ribeiro, Juliana Siqueira-Gay, Ane Alencar, Sassan Saatchi, Luiz E. O. C. Aragão, Liana O. Anderson, and Maycon Melo
- Subjects
Medicine ,Science - Abstract
Abstract Studies showed that Brazilian Amazon indigenous territories (ITs) are efficient models for preserving forests by reducing deforestation, fires, and related carbon emissions. Considering the importance of ITs for conserving socio-environmental and cultural diversity and the recent climb in the Brazilian Amazon deforestation, we used official remote sensing datasets to analyze deforestation inside and outside indigenous territories within Brazil's Amazon biome during the 2013–2021 period. Deforestation has increased by 129% inside ITs since 2013, followed by an increase in illegal mining areas. In 2019–2021, deforestation was 195% higher and 30% farther from the borders towards the interior of indigenous territories than in previous years (2013–2018). Furthermore, about 59% of carbon dioxide (CO2) emissions within ITs in 2013–2021 (96 million tons) occurred in the last three years of analyzed years, revealing the magnitude of increasing deforestation to climate impacts. Therefore, curbing deforestation in indigenous territories must be a priority for the Brazilian government to secure these peoples' land rights, ensure the forests' protection and regulate the global climate.
- Published
- 2023
- Full Text
- View/download PDF
14. An emotional discrete controller PSO tuned and designed for a real industrial pumping system
- Author
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Davidson C. Marques, Jeydson L. Silva, Milde Maria S. Lira, and Ronaldo R. B. Aquino
- Subjects
Medicine ,Science - Abstract
Abstract The application of automation techniques to water pump systems, combined with modern control techniques, has been increasing the hydraulic and energy efficiency of such systems. In this context, the objective of this work is to present an intelligent method of flow control based on Brain Emotional Learning Basic Intelligent Control (BELBIC), which will be applied to an experimental workbench of a pumping system, located in the Energy Efficiency and Energy Quality Laboratory (LEEQE) at Federal University of Pernambuco (UFPE). The parameters of this controller are optimized with a particle swarm optimization (PSO) technique with minimization of Integral Absolute Error (IAE). Initial tests were performed in a computational environment so that the system’s performance could be pre-tested, thereby the dynamics of the system was modeled from real data generated in the process. The experimental results were obtained through the implementation of this control system in a programmable logic controller (PLC), which was the device responsible for all the automation of the workbench previously mentioned. The data of this workbench were collected using a supervisory system exclusively developed for this work. These data were then used to analyze the performance of the proposed control system, which demonstrated that its behavior was efficient.
- Published
- 2022
- Full Text
- View/download PDF
15. The gut microbiome of exudivorous marmosets in the wild and captivity
- Author
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Joanna Malukiewicz, Reed A. Cartwright, Jorge A. Dergam, Claudia S. Igayara, Sharon E. Kessler, Silvia B. Moreira, Leanne T. Nash, Patricia A. Nicola, Luiz C. M. Pereira, Alcides Pissinatti, Carlos R. Ruiz-Miranda, Andrew T. Ozga, Adriana A. Quirino, Christian Roos, Daniel L. Silva, Anne C. Stone, and Adriana D. Grativol
- Subjects
Medicine ,Science - Abstract
Abstract Mammalian captive dietary specialists like folivores are prone to gastrointestinal distress and primate dietary specialists suffer the greatest gut microbiome diversity losses in captivity compared to the wild. Marmosets represent another group of dietary specialists, exudivores that eat plant exudates, but whose microbiome remains relatively less studied. The common occurrence of gastrointestinal distress in captive marmosets prompted us to study the Callithrix gut microbiome composition and predictive function through bacterial 16S ribosomal RNA V4 region sequencing. We sampled 59 wild and captive Callithrix across four species and their hybrids. Host environment had a stronger effect on the gut microbiome than host taxon. Wild Callithrix gut microbiomes were enriched for Bifidobacterium, which process host-indigestible carbohydrates. Captive marmoset guts were enriched for Enterobacteriaceae, a family containing pathogenic bacteria. While gut microbiome function was similar across marmosets, Enterobacteriaceae seem to carry out most functional activities in captive host guts. More diverse bacterial taxa seem to perform gut functions in wild marmosets, with Bifidobacterium being important for carbohydrate metabolism. Captive marmosets showed gut microbiome composition aspects seen in human gastrointestinal diseases. Thus, captivity may perturb the exudivore gut microbiome, which raises implications for captive exudivore welfare and calls for husbandry modifications.
- Published
- 2022
- Full Text
- View/download PDF
16. Comparative effects of dexmedetomidine and propofol on brain and lung damage in experimental acute ischemic stroke
- Author
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Giselle C. Sousa, Marcos Vinicius Fernandes, Fernanda F. Cruz, Mariana A. Antunes, Carla M. da Silva, Christina Takyia, Denise Battaglini, Cynthia S. Samary, Chiara Robba, Paolo Pelosi, Patricia R. M. Rocco, and Pedro L. Silva
- Subjects
Medicine ,Science - Abstract
Abstract Acute ischemic stroke is associated with pulmonary complications, and often dexmedetomidine and propofol are used to decrease cerebral metabolic rate. However, it is unknown the immunomodulatory actions of dexmedetomidine and propofol on brain and lungs during acute ischemic stroke. The effects of dexmedetomidine and propofol were compared on perilesional brain tissue and lung damage after acute ischemic stroke in rats. Further, the mean amount of both sedatives was directly evaluated on alveolar macrophages and lung endothelial cells primarily extracted 24-h after acute ischemic stroke. In twenty-five Wistar rats, ischemic stroke was induced and after 24-h treated with sodium thiopental (STROKE), dexmedetomidine and propofol. Dexmedetomidine, compared to STROKE, reduced diffuse alveolar damage score [median(interquartile range); 12(7.8–15.3) vs. 19.5(18–24), p = 0.007)], bronchoconstriction index [2.28(2.08–2.36) vs. 2.64(2.53–2.77), p = 0.006], and TNF-α expression (p = 0.0003), while propofol increased VCAM-1 expression compared to STROKE (p = 0.0004). In perilesional brain tissue, dexmedetomidine, compared to STROKE, decreased TNF-α (p = 0.010), while propofol increased VCAM-1 compared to STROKE (p = 0.024). In alveolar macrophages and endothelial cells, dexmedetomidine decreased IL-6 and IL-1β compared to STROKE (p = 0.002, and p = 0.040, respectively), and reduced IL-1β compared to propofol (p = 0.014). Dexmedetomidine, but not propofol, induced brain and lung protection in experimental acute ischemic stroke.
- Published
- 2021
- Full Text
- View/download PDF
17. Genomic skimming and nanopore sequencing uncover cryptic hybridization in one of world’s most threatened primates
- Author
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Joanna Malukiewicz, Reed A. Cartwright, Jorge A. Dergam, Claudia S. Igayara, Patricia A. Nicola, Luiz M. C. Pereira, Carlos R. Ruiz-Miranda, Anne C. Stone, Daniel L. Silva, Fernanda de Fatima Rodrigues da Silva, Arvind Varsani, Lutz Walter, Melissa A. Wilson, Dietmar Zinner, and Christian Roos
- Subjects
Medicine ,Science - Abstract
Abstract The Brazilian buffy-tufted-ear marmoset (Callithrix aurita), one of the world’s most endangered primates, is threatened by anthropogenic hybridization with exotic, invasive marmoset species. As there are few genetic data available for C. aurita, we developed a PCR-free protocol with minimal technical requirements to rapidly generate genomic data with genomic skimming and portable nanopore sequencing. With this direct DNA sequencing approach, we successfully determined the complete mitogenome of a marmoset that we initially identified as C. aurita. The obtained nanopore-assembled sequence was highly concordant with a Sanger sequenced version of the same mitogenome. Phylogenetic analyses unexpectedly revealed that our specimen was a cryptic hybrid, with a C. aurita phenotype and C. penicillata mitogenome lineage. We also used publicly available mitogenome data to determine diversity estimates for C. aurita and three other marmoset species. Mitogenomics holds great potential to address deficiencies in genomic data for endangered, non-model species such as C. aurita. However, we discuss why mitogenomic approaches should be used in conjunction with other data for marmoset species identification. Finally, we discuss the utility and implications of our results and genomic skimming/nanopore approach for conservation and evolutionary studies of C. aurita and other marmosets.
- Published
- 2021
- Full Text
- View/download PDF
18. Recombinant BCG Expressing LTAK63 Adjuvant induces Superior Protection against Mycobacterium tuberculosis
- Author
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Ivan P. Nascimento, Dunia Rodriguez, Carina C. Santos, Eduardo P. Amaral, Henrique K. Rofatto, Ana P. Junqueira-Kipnis, Eduardo D. C. Gonçalves, Maria R. D’Império-Lima, Mario H. Hirata, Celio L. Silva, Nathalie Winter, Brigitte Gicquel, Kingston H. G. Mills, Mariagrazia Pizza, Rino Rappuoli, and Luciana C. C. Leite
- Subjects
Medicine ,Science - Abstract
Abstract In order to develop an improved BCG vaccine against tuberculosis we have taken advantage of the adjuvant properties of a non-toxic derivative of Escherichia coli heat labile enterotoxin (LT), LTAK63. We have constructed rBCG strains expressing LTAK63 at different expression levels. Mice immunized with BCG expressing low levels of LTAK63 (rBCG-LTAK63lo) showed higher Th1 cytokines and IL-17 in the lungs, and when challenged intratracheally with Mycobacterium tuberculosis displayed a 2.0–3.0 log reduction in CFU as compared to wild type BCG. Histopathological analysis of lung tissues from protected mice revealed a reduced inflammatory response. Immunization with rBCG-LTAK63lo also protected against a 100-fold higher challenge dose. Mice immunized with rBCG-LTAK63lo produced an increase in TGF-β as compared with BCG after challenge, with a corresponding reduction in Th1 and Th17 cytokines, as determined by Real Time RT-PCR. Furthermore, rBCG-LTAK63lo also displays protection against challenge with a highly virulent Beijing isolate. Our findings suggest that BCG with low-level expression of the LTAK63 adjuvant induces a stronger immune response in the lungs conferring higher levels of protection, and a novel mechanism subsequently triggers a regulatory immune response, which then limits the pathology. The rBCG-LTAK63lo strain can be the basis of an improved vaccine against tuberculosis.
- Published
- 2017
- Full Text
- View/download PDF
19. Amide hydrogens reveal a temperature-dependent structural transition that enhances site-II Ca2+-binding affinity in a C-domain mutant of cardiac troponin C
- Author
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Tiago Veltri, Guilherme A. P. de Oliveira, Ewa A. Bienkiewicz, Fernando L. Palhano, Mayra de A. Marques, Adolfo H. Moraes, Jerson L. Silva, Martha M. Sorenson, and Jose R. Pinto
- Subjects
Medicine ,Science - Abstract
Abstract The hypertrophic cardiomyopathy-associated mutant D145E, in cardiac troponin C (cTnC) C-domain, causes generalised instability at multiple sites in the isolated protein. As a result, structure and function of the mutant are more susceptible to higher temperatures. Above 25 °C there are large, progressive increases in N-domain Ca2+-binding affinity for D145E but only small changes for the wild-type protein. NMR-derived backbone amide temperature coefficients for many residues show a sharp transition above 30–40 °C, indicating a temperature-dependent conformational change that is most prominent around the mutated EF-hand IV, as well as throughout the C-domain. Smaller, isolated changes occur in the N-domain. Cardiac skinned fibres reconstituted with D145E are more sensitive to Ca2+ than fibres reconstituted with wild-type, and this defect is amplified near body-temperature. We speculate that the D145E mutation destabilises the native conformation of EF-hand IV, leading to a transient unfolding and dissociation of helix H that becomes more prominent at higher temperatures. This creates exposed hydrophobic surfaces that may be capable of binding unnaturally to a variety of targets, possibly including the N-domain of cTnC when it is in its open Ca2+-saturated state. This would constitute a potential route for propagating signals from one end of TnC to the other.
- Published
- 2017
- Full Text
- View/download PDF
20. High dose cholecalciferol supplementation causing morning blood pressure reduction in patients with type 1 diabetes mellitus and cardiovascular autonomic neuropathy.
- Author
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Felício J, Moraes L, Lemos G, Souza Í, Vieira G, Silva L, Queiroz N, Souza AC, Melo F, Neto JFA, Britto H, Lemos M, Santos M, Figueiredo P, Motta AR, Reis M, Caldeira G, Leal V, Piani P, Aquino V, and Felício K
- Subjects
- Humans, Blood Pressure physiology, Blood Pressure Monitoring, Ambulatory, Cholecalciferol therapeutic use, Circadian Rhythm physiology, Dietary Supplements, Prospective Studies, Diabetes Mellitus, Type 1 complications, Diabetes Mellitus, Type 1 drug therapy, Hypertension, Hypotension
- Abstract
We evaluated the association of cardiovascular autonomic neuropathy (CAN), blood pressure (BP) and Vitamin D (VD) levels before and after high-dose cholecalciferol supplementation (4000/10,000) UI/day) for 12 weeks in patients (N = 67) with type 1 diabetes mellitus (T1DM). Based on this prospective controlled pilot study, patients were divided into group 1 (N = 23 with CAN) and group 2 (N = 44 without CAN). At baseline, group 1 had higher systolic BP (SBP) during sleep (115 ± 14 vs. 107 ± 12 mmHg, p = 0.04) and lower nocturnal dipping (3 ± 5 vs. 8 ± 6%, p = 0.009). Among those with loss of nocturnal dipping, 45.4% (20/44) had CAN, while in normal nocturnal dipping group it occurred only in 13% (3/23) (p = 0.007). Non-dipper group had worse CAN parameters when compared to dipper group [Very low frequency (VLF) (2.5 ± 0.5vs.2.8 ± 0.4 s, p = 0.01), total power (TP) (2.9 ± 0.6 vs. 3.3 ± 0.4 s, p = 0.01), Valsalva coefficient (1.5 ± 0.4 vs. 1.8 ± 0.6, p = 0.06)]. After VD, only group 1 improved CAN parameters [TP (2.5 ± 0.4 vs. 2.8 ± 0.6, p = 0.01) and VLF (2.2 ± 0.4 vs. 2.4 ± 0.5, p = 0.03). Group 1 presented a reduction in morning SBP (120 ± 20 vs. 114 ± 17 mmHg, p = 0.038) and in morning SBP surge (13 ± 13 vs. 5 ± 14, p = 0.04). High-dose VD was associated with improved CAN parameters and reduced awake SBP and morning SBP surge. These findings suggest that VD may benefit patients with cardiovascular autonomic neuropathy. ISRCTN32601947, registration date: 31/07/2017., (© 2024. The Author(s).)
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- 2024
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21. Author Correction: Crypsis by background matching and disruptive coloration as drivers of substrate occupation in sympatric Amazonian bark praying mantises.
- Author
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de Alcantara Viana JV, Campos Duarte R, Vieira C, Augusto Poleto Antiqueira P, Bach A, de Mello G, Silva L, Rabelo Oliveira Leal C, and Quevedo Romero G
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- 2023
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22. Crypsis by background matching and disruptive coloration as drivers of substrate occupation in sympatric Amazonian bark praying mantises.
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de Alcantara Viana JV, Campos Duarte R, Vieira C, Augusto Poleto Antiqueira P, Bach A, de Mello G, Silva L, Rabelo Oliveira Leal C, and Quevedo Romero G
- Subjects
- Animals, Humans, Plant Bark, Sympatry, Color, Vision, Ocular, Predatory Behavior, Pigmentation, Mantodea
- Abstract
Background matching and disruptive coloration are common camouflage strategies in nature, but few studies have accurately measured their protective value in living organisms. Amazon's Bark praying mantises exhibit colour patterns matching whitish and greenish-brown tree trunks. We tested the functional significance of background matching and disruptive coloration of different praying mantis morphospecies (white, grey and green) detected by DNA barcoding. Through image analysis, avian visual models and field experiments using humans as potential predators, we explored whether the background occupation of mantises provides camouflage against predation. Data were obtained for individuals against their occupied tree trunks (whitish or greenish-brown) and microhabitats (lichen or bryophyte patches), compared to non-occupied trunks. White and grey mantises showed lower colour contrasts against occupied trunks at the scale of tree trunk, with no differences in luminance contrasts. Conversely, green mantises showed lower colour and luminance contrasts against microhabitats and also exhibited high edge disruption against greenish-brown trunks. The camouflage of white and green mantis models against colour-matching trunks increased search time and reduced encounter distance of human predators. We highlight the importance of camouflage strategies at different spatial scales to enhance individual survival against predators. Specifically, we present a stunning study system to investigate the relationship of phylogenetically related species that use camouflage in sympatry., (© 2023. The Author(s).)
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- 2023
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23. Single-base resolution methylomes of somatic embryogenesis in Theobroma cacao L. reveal epigenome modifications associated with somatic embryo abnormalities.
- Author
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Garcia C, Furtado de Almeida AA, Costa M, Britto D, Correa F, Mangabeira P, Silva L, Silva J, Royaert S, and Marelli JP
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- Embryonic Development genetics, Epigenome, Ethylenes metabolism, Hypoxia metabolism, Plant Somatic Embryogenesis Techniques methods, Seeds genetics, Seeds metabolism, Cacao genetics, Cacao metabolism
- Abstract
Propagation by somatic embryogenesis in Theobroma cacao has some issues to be solved, as many morphologically abnormal somatic embryos that do not germinate into plants are frequently observed, thus hampering plant production on a commercial scale. For the first time the methylome landscape of T. cacao somatic embryogenesis was examined, using whole-genome bisulfite sequencing technique, with the aim to understand the epigenetic basis of somatic embryo abnormalities. We identified 873 differentially methylated genes (DMGs) in the CpG context between zygotic embryos, normal and abnormal somatic embryos, with important roles in development, programmed cell death, oxidative stress, and hypoxia induction, which can help to explain the morphological abnormalities of somatic embryos. We also identified the role of ethylene and its precursor 1-aminocyclopropane-1-carboxylate in several biological processes, such as hypoxia induction, cell differentiation and cell polarity, that could be associated to the development of abnormal somatic embryos. The biological processes and the hypothesis of ethylene and its precursor involvement in the somatic embryo abnormalities in cacao are discussed., (© 2022. The Author(s).)
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- 2022
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24. Taxonomic, structural diversity and carbon stocks in a gradient of island forests.
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Borges Silva LC, Pavão DC, Elias RB, Moura M, Ventura MA, and Silva L
- Abstract
Assessment of forest ecosystems and their services is seen as a key action for the advancement of biodiversity objectives, and to inform the development and implementation of related policies and planning. The Azorean forest is important for timber production, the protection of soil and water resources, and for its recreational and aesthetic value. However, its role in carbon accumulation has not been fully addressed. We assessed plant diversity, forest structure and carbon stocks in a gradient of three forest types (Natural Forest-NF; Exotic Woodland-EW and Production Forest-PF) in three of the Azores islands. We used biodiversity indices and found that NF harbored the highest plant diversity levels and PF the lowest. Diversity levels were lower for structural than for taxonomic data, particularly for PF. The highest tree carbon stock was found at EW in one of the islands, while PF consistently exhibited relatively high tree carbon stocks in the three islands. The largest soil carbon stocks were found at EW, while leaf litter carbon stocks were higher at PF. We concluded that NF play a fundamental role as plant diversity hotspots but have lower relevance as carbon stocks what might be associated with montane environmental conditions. PFs provide economic assets and act as carbon sinks, while EWs play a major role as carbon sinks in soil, but also at tree level in the oldest forests., (© 2022. The Author(s).)
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- 2022
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25. Identification of key proteins in the signaling crossroads between wound healing and cancer hallmark phenotypes.
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López-Cortés A, Abarca E, Silva L, Velastegui E, León-Sosa A, Karolys G, Cabrera F, and Caicedo A
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- Gene Expression Profiling methods, Genetic Predisposition to Disease genetics, Genomics methods, Homeostasis genetics, Homeostasis physiology, Humans, Mutation, Neoplasms genetics, Phenotype, Protein Interaction Maps genetics, Proteome genetics, Signal Transduction genetics, Tumor Microenvironment genetics, Wound Healing genetics, Neoplasms metabolism, Proteome metabolism, Proteomics methods, Signal Transduction physiology, Wound Healing physiology
- Abstract
Wound healing (WH) and cancer seem to share common cellular and molecular processes that could work in a tight balance to maintain tissue homeostasis or, when unregulated, drive tumor progression. The "Cancer Hallmarks" comprise crucial biological properties that mediate the advancement of the disease and affect patient prognosis. These hallmarks have been proposed to overlap with essential features of the WH process. However, common hallmarks and proteins actively participating in both processes have yet to be described. In this work we identify 21 WH proteins strongly linked with solid tumors by integrated TCGA Pan-Cancer and multi-omics analyses. These proteins were associated with eight of the ten described cancer hallmarks, especially avoiding immune destruction. These results show that WH and cancer's common proteins are involved in the microenvironment modification of solid tissues and immune system regulation. This set of proteins, between WH and cancer, could represent key targets for developing therapies., (© 2021. The Author(s).)
- Published
- 2021
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26. The prevalence of rheumatoid arthritis in Spain.
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Silva-Fernández L, Macía-Villa C, Seoane-Mato D, Cortés-Verdú R, Romero-Pérez A, Quevedo-Vila V, Fábregas-Canales D, Antón-Pagés F, Añez G, Brandy A, Martínez-Dubois C, Rubio-Muñoz P, Sánchez-Piedra C, Díaz-González F, and Bustabad-Reyes S
- Subjects
- Adult, Age Distribution, Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Health Surveys, Humans, Male, Middle Aged, Prevalence, Sex Distribution, Sex Factors, Spain epidemiology, Young Adult, Arthritis, Rheumatoid epidemiology
- Abstract
Rheumatoid arthritis (RA) prevalence is believed to be around 1% worldwide, although it varies considerably among different populations. The aim of EPISER2016 study was to estimate the prevalence of RA in the general adult population in Spain. We designed a population-based cross-sectional study. A national survey was conducted between November 2016 and October 2017 involving a probabilistic sample from the general population aged 20 years or older. Subjects were randomly selected for phone screening using a computer-assisted telephone interviewer system. Positive RA screening results were evaluated by a rheumatologist. Cases fulfilled the 1987 ACR and/or the 2010 ACR/EULAR criteria; previous diagnosis established by a rheumatologist and clearly identified in medical records were also accepted regardless of the criteria used. Prevalence estimates with 95% CI were calculated taking into account the design of the sample (weighting based on age, sex, and geographic origin using as a reference the distribution of the population in Spain). 4916 subjects participated in the study and 39 RA cases were confirmed. RA estimated prevalence was 0.82% (95% CI 0.59-1.15). Mean age of RA cases was 60.48 (14.85) years, they were more frequently women (61.5%), from urban areas (74.4%), non-smokers (43.6%), and with a high body mass index (53.8% with overweight). Extrapolating to the population in Spain (approximately 37 million are ≥ 20 years old), it was estimated that there were between 220,000 and 430,000 people aged 20 years or older with RA. No undiagnosed cases were detected, which could be related to the establishment of early arthritis clinics around the country, increasing the rates of diagnosis during early phases of RA.
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- 2020
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27. Zika virus infection in pregnancy and infant growth, body composition in the first three months of life: a cohort study.
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Soares F, Abranches AD, Villela L, Lara S, Araújo D, Nehab S, Silva L, Amaral Y, Junior SCG, Pone S, Lobkowicz L, Clemente NS, Brasil P, Nielsen-Saines K, Pone M, Brickley E, and Moreira ME
- Subjects
- Adult, Body Weight physiology, Cohort Studies, Female, Gestational Age, Humans, Infant, Infant, Newborn, Male, Microcephaly physiopathology, Microcephaly virology, Pregnancy, Pregnancy Complications, Infectious virology, Prospective Studies, Body Composition physiology, Pregnancy Complications, Infectious physiopathology, Zika Virus pathogenicity, Zika Virus Infection complications
- Abstract
The implications of Zika Virus exposure in pregnancy for early infant growth remains poorly described. The main goal of this study is to compare the growth, body composition, and feeding modality of infants in the first three months of life by prenatal Zika Virus exposure status. We selected an analytical cohort of 115 infants born without microcephaly, comprising 56 infants with qRT-PCR confirmed exposure to ZIKV during gestation and 59 infants born to women with presumptively no evidence of ZIKV in pregnancy. Infants were evaluated at birth, 1 and 3 months of age in terms of anthropometrics, body composition All the results were adjusted by maternal age, maternal BMI and gestational age. We observe no differences between anthropometric measurements at birth. Mothers in exposed group showed higher BMI. At 1 month and 3 months of age there were differences in mid arm circumference, arm muscle circumference and fat free mass. Weight and length was less in the ZIKV exposed in pregnancy infants and statistically different at 3 month of age. The findings of this investigation provide new evidence that ZIKV exposure in pregnancy may be associated with differences in body composition.
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- 2019
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28. Restructuring of the 'Macaronesia' biogeographic unit: A marine multi-taxon biogeographical approach.
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Freitas R, Romeiras M, Silva L, Cordeiro R, Madeira P, González JA, Wirtz P, Falcón JM, Brito A, Floeter SR, Afonso P, Porteiro F, Viera-Rodríguez MA, Neto AI, Haroun R, Farminhão JNM, Rebelo AC, Baptista L, Melo CS, Martínez A, Núñez J, Berning B, Johnson ME, and Ávila SP
- Abstract
The Azores, Madeira, Selvagens, Canary Islands and Cabo Verde are commonly united under the term "Macaronesia". This study investigates the coherency and validity of Macaronesia as a biogeographic unit using six marine groups with very different dispersal abilities: coastal fishes, echinoderms, gastropod molluscs, brachyuran decapod crustaceans, polychaete annelids, and macroalgae. We found no support for the current concept of Macaronesia as a coherent marine biogeographic unit. All marine groups studied suggest the exclusion of Cabo Verde from the remaining Macaronesian archipelagos and thus, Cabo Verde should be given the status of a biogeographic subprovince within the West African Transition province. We propose to redefine the Lusitanian biogeographical province, in which we include four ecoregions: the South European Atlantic Shelf, the Saharan Upwelling, the Azores, and a new ecoregion herein named Webbnesia, which comprises the archipelagos of Madeira, Selvagens and the Canary Islands.
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- 2019
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29. Tupanvirus-infected amoebas are induced to aggregate with uninfected cells promoting viral dissemination.
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Oliveira G, Silva L, Leão T, Mougari S, da Fonseca FG, Kroon EG, La Scola B, and Abrahão JS
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- Amoeba cytology, Giant Viruses genetics, Lectins, C-Type metabolism, Mannose pharmacology, Mannose Receptor, Mannose-Binding Lectins metabolism, Receptors, Cell Surface metabolism, Amoeba virology, Cell Aggregation drug effects, Giant Viruses pathogenicity, Host-Pathogen Interactions, Virus Diseases transmission
- Abstract
The discovery of giant viruses in the last years has fascinated the scientific community due to virus particles size and genome complexity. Among such fantastic discoveries, we have recently described tupanviruses, which particles present a long tail, and has a genome that contains the most complete set of translation-related genes ever reported in the known virosphere. Here we describe a new kind of virus-host interaction involving tupanvirus. We observed that tupanvirus-infected amoebas were induced to aggregate with uninfected cells, promoting viral dissemination and forming giant host cell bunches. Even after mechanical breakdown of bunches, amoebas reaggregated within a few minutes. This remarkable interaction between infected and uninfected cells seems to be promoted by the expression of a mannose receptor gene. Our investigations demonstrate that the pre-treatment of amoebas with free mannose inhibits the formation of bunches, in a concentration-dependent manner, suggesting that amoebal-bunch formation correlates with mannose receptor gene expression. Finally, our data suggest that bunch-forming cells are able to interact with uninfected cells promoting the dissemination and increase of tupanvirus progeny.
- Published
- 2019
- Full Text
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