644 research outputs found

    Topological Homogeneity for Electron Microscopy Images

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    In this paper, the concept of homogeneity is defined, from a topological perspective, in order to analyze how uniform is the material composition in 2D electron microscopy images. Topological multiresolution parameters are taken into account to obtain better results than classical techniques.Ministerio de Economía y Competitividad MTM2016-81030-PMinisterio de Economía y Competitividad TEC2012-37868-C04-0

    Cavity Induced Interfacing of Atoms and Light

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    This chapter introduces cavity-based light-matter quantum interfaces, with a single atom or ion in strong coupling to a high-finesse optical cavity. We discuss the deterministic generation of indistinguishable single photons from these systems; the atom-photon entanglement intractably linked to this process; and the information encoding using spatio-temporal modes within these photons. Furthermore, we show how to establish a time-reversal of the aforementioned emission process to use a coupled atom-cavity system as a quantum memory. Along the line, we also discuss the performance and characterisation of cavity photons in elementary linear-optics arrangements with single beam splitters for quantum-homodyne measurements.Comment: to appear as a book chapter in a compilation "Engineering the Atom-Photon Interaction" published by Springer in 2015, edited by A. Predojevic and M. W. Mitchel

    Hyperoside Supplementation in Preservation Media Surpasses Vitamin C Protection Against Oxidative Stress-Induced Damages in Human Spermatozoa

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    Background/Aims: Oxidative Stress (OS) is reported as one of the main causes of male infertility. Infertile couples often resort to assisted reproductive technology (ART) to achieve parenthood. However, preparation for ART protocols increases the exposer of gametes to OS. Thus, it is crucial to find suitable preservation media that can counteract the OS-induced damages in spermatozoa. In this work, we tested and compared the efficiency of vitamin C (VC) and hyperoside (HYP) as potential antioxidant supplements for sperm preservation media. Methods: We evaluated the cytotoxicity of HYP (0, 5, 50, 100, and 500 µM) in spermatozoa. After incubation of sperm cells with VC (600 µM) and HYP (100 and 500 µM), in the presence and absence of H2O2 (300 µM), the following parameters were assessed: total sperm motility and vitality, OS biomarkers expression, total antioxidant capacity (TAC) of the media, percentage of DNA fragmentation, mitochondrial membrane potential (MMP), and metabolite quantification of the media by proton nuclear magnetic resonance (1H-NMR). Results: The supplementation with VC (600 µM) and HYP (100 and 500 µM) did not induce any deleterious effects to the physiology and metabolism of the spermatozoa, after 1-hour of treatment. In the presence of H2O2 (300 µM), both VC and HYP were able to prevent some of the deleterious effects of H2O2 in sperm, which were represented by an increase in sperm motility, a decrease in DNA fragmentation, and a decreasing trend in lipid peroxidation levels. However, these antioxidants were not able to prevent the decrease of MMP associated with H2O2 treatment, nor were able to prevent the conversion of pyruvate into acetate (a reaction promoted by H2O2). Conclusion: The supplementation of sperm preservation media with VC and HYP could be beneficial for the preservation of sperm physiology. From the antioxidant conditions tested, the supplementation of media with HYP (100 µM) demonstrated the best results regarding sperm preservation, evidencing the higher antioxidant capacity of HYP compared to VC. Nevertheless, none of the antioxidants used was able to prevent the metabolic alterations promoted by H2O2 in spermatozoa.This work was supported by Fundação para a Ciência e a Tecnologia - FCT to Sara C. Pereira (2021.05487.BD); David F. Carrageta (SFRH/BD/136779/2018); Marco G. Alves (IFCT2015 and PTDC/MEC-AND/28691/2017); LAQV-REQUIMTE (UIDB/50006/2020); UMIB (UIDB/00215/2020, and UIDP/00215/2020); ITR - Laboratory for Integrative and Translational Research in Population Health (LA/P/0064/2020). Pedro F. Oliveira was funded by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the Scientific Employment Stimulus - Institutional Call - reference CEECINST/00026/2018

    Obesity-induced hypoadiponectinaemia: the opposite influences of central and peripheral fat compartments

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    Background and Aims:\textbf{Background and Aims:} The substantial reduction in adiponectin concentration among obese individuals seems to depend on fat distribution and is a marker of metabolic and adipose tissue dysfunction. We aimed to: (i) address whether abdominal fat from different compartments (visceral, deep subcutaneous abdominal and superficial subcutaneous abdominal) and gluteofemoral fat are independently associated with blood adiponectin concentration; and (ii) investigate whether abdominal (proxied by waist circumference) and gluteofemoral fat (proxied by hip circumference) accumulation causally determine blood adiponectin concentration. Methods:\textbf{Methods:} To investigate the independent association of abdominal and gluteofemoral fat with adiponectin concentration, we used multivariable regression and data from 30-year-old adults from the 1982 Pelotas Birth Cohort (nn = 2,743). To assess the causal role of abdominal and gluteofemoral fat accumulation on adiponectin concentration, we used Mendelian randomization and data from two consortia of genome-wide association studies—the GIANT (nn > 210 000) and ADIPOGen consortia (nn = 29 347). Results:\textbf{Results:} In the multivariable regression analysis, all abdominal fat depots were negatively associated with adiponectin concentration, specially visceral abdominal fat [men: β\beta = -0.24 standard unit of log adiponectin per standard unit increase in abdominal fat; 95% confidence interval (CI) = -0.31, -0.18; PP = 8*1013^{-13}; women: β\beta = -0.31; 95% CI = -0.36, -0.25; PP = 7*1027^{-27}), whereas gluteofemoral fat was positively associated with adiponectin concentration (men: β\beta = 0.13 standard unit of log adiponectin per standard unit increase in gluteofemoral fat; 95% CI = 0.03, 0.22; PP = 0.008; women: β\beta = 0.24; 95% CI = 0.17, 0.31; PP = 7*1011^{-11}). In the Mendelian randomization analysis, genetically-predicted waist circumference was inversely related to blood adiponectin concentration (β\beta = -0.27 standard unit of log adiponectin per standard unit increase in waist circumference; 95% CI = -0.36, -0.19; PP = 2*1011^{-11}), whereas genetically-predicted hip circumference was positively associated with blood adiponectin concentration (β\beta = 0.17 standard unit of log adiponectin per standard unit increase in hip circumference; 95% CI = 0.11, 0.24; PP = 1*107^{-7}). Conclusions:\textbf{Conclusions:} These results support the hypotheses that there is a complex interplay between body fat distribution and circulating adiponectin concentration, and that whereas obesity-induced hypoadiponectinaemia seems to be primarily attributed to abdominal fat accumulation, gluteofemoral fat accumulation is likely to exert a protective effect.The study ‘Pelotas Birth Cohort, 1982’ is conducted by Postgraduate Program in Epidemiology at Universidade Federal de Pelotas with the collaboration of the Brazilian Public Health Association (ABRASCO). From 2004 to 2013, the Wellcome Trust supported the 1982 birth cohort study. The International Development Research Center, World Health Organization, Overseas Development Administration, European Union, National Support Program for Centers of Excellence (PRONEX), the Brazilian National Research Council (CNPq) and the Brazilian Ministry of Health supported previous phases of the study. M.C.B. receives financial support from the Brazilian National Research Council (CNPq) [144749/2014-9, 201498/2014-6 (Science Without Borders Program), and 163291/2015-2] and Coordenac¸~ao de Aperfeic¸oamento de Pessoal de Nıvel Superior (CAPES). K.K.O. is supported by the Medical Research Council [Unit Programme numbers MC_UU_12015/1 and MC_UU_12015/2]

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    Obesity-induced hypoadiponectinaemia: the opposite influences of central and peripheral fat compartments

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    Background and Aims:\textbf{Background and Aims:} The substantial reduction in adiponectin concentration among obese individuals seems to depend on fat distribution and is a marker of metabolic and adipose tissue dysfunction. We aimed to: (i) address whether abdominal fat from different compartments (visceral, deep subcutaneous abdominal and superficial subcutaneous abdominal) and gluteofemoral fat are independently associated with blood adiponectin concentration; and (ii) investigate whether abdominal (proxied by waist circumference) and gluteofemoral fat (proxied by hip circumference) accumulation causally determine blood adiponectin concentration. Methods:\textbf{Methods:} To investigate the independent association of abdominal and gluteofemoral fat with adiponectin concentration, we used multivariable regression and data from 30-year-old adults from the 1982 Pelotas Birth Cohort (nn = 2,743). To assess the causal role of abdominal and gluteofemoral fat accumulation on adiponectin concentration, we used Mendelian randomization and data from two consortia of genome-wide association studies—the GIANT (nn > 210 000) and ADIPOGen consortia (nn = 29 347). Results:\textbf{Results:} In the multivariable regression analysis, all abdominal fat depots were negatively associated with adiponectin concentration, specially visceral abdominal fat [men: β\beta = -0.24 standard unit of log adiponectin per standard unit increase in abdominal fat; 95% confidence interval (CI) = -0.31, -0.18; PP = 8*1013^{-13}; women: β\beta = -0.31; 95% CI = -0.36, -0.25; PP = 7*1027^{-27}), whereas gluteofemoral fat was positively associated with adiponectin concentration (men: β\beta = 0.13 standard unit of log adiponectin per standard unit increase in gluteofemoral fat; 95% CI = 0.03, 0.22; PP = 0.008; women: β\beta = 0.24; 95% CI = 0.17, 0.31; PP = 7*1011^{-11}). In the Mendelian randomization analysis, genetically-predicted waist circumference was inversely related to blood adiponectin concentration (β\beta = -0.27 standard unit of log adiponectin per standard unit increase in waist circumference; 95% CI = -0.36, -0.19; PP = 2*1011^{-11}), whereas genetically-predicted hip circumference was positively associated with blood adiponectin concentration (β\beta = 0.17 standard unit of log adiponectin per standard unit increase in hip circumference; 95% CI = 0.11, 0.24; PP = 1*107^{-7}). Conclusions:\textbf{Conclusions:} These results support the hypotheses that there is a complex interplay between body fat distribution and circulating adiponectin concentration, and that whereas obesity-induced hypoadiponectinaemia seems to be primarily attributed to abdominal fat accumulation, gluteofemoral fat accumulation is likely to exert a protective effect.The study ‘Pelotas Birth Cohort, 1982’ is conducted by Postgraduate Program in Epidemiology at Universidade Federal de Pelotas with the collaboration of the Brazilian Public Health Association (ABRASCO). From 2004 to 2013, the Wellcome Trust supported the 1982 birth cohort study. The International Development Research Center, World Health Organization, Overseas Development Administration, European Union, National Support Program for Centers of Excellence (PRONEX), the Brazilian National Research Council (CNPq) and the Brazilian Ministry of Health supported previous phases of the study. M.C.B. receives financial support from the Brazilian National Research Council (CNPq) [144749/2014-9, 201498/2014-6 (Science Without Borders Program), and 163291/2015-2] and Coordenac¸~ao de Aperfeic¸oamento de Pessoal de Nıvel Superior (CAPES). K.K.O. is supported by the Medical Research Council [Unit Programme numbers MC_UU_12015/1 and MC_UU_12015/2]

    Systematic and Evolutionary Insights Derived from mtDNA COI Barcode Diversity in the Decapoda (Crustacea: Malacostraca)

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    Background: Decapods are the most recognizable of all crustaceans and comprise a dominant group of benthic invertebrates of the continental shelf and slope, including many species of economic importance. Of the 17635 morphologically described Decapoda species, only 5.4% are represented by COI barcode region sequences. It therefore remains a challenge to compile regional databases that identify and analyse the extent and patterns of decapod diversity throughout the world. Methodology/Principal Findings: We contributed 101 decapod species from the North East Atlantic, the Gulf of Cadiz and the Mediterranean Sea, of which 81 species represent novel COI records. Within the newly-generated dataset, 3.6% of the species barcodes conflicted with the assigned morphological taxonomic identification, highlighting both the apparent taxonomic ambiguity among certain groups, and the need for an accelerated and independent taxonomic approach. Using the combined COI barcode projects from the Barcode of Life Database, we provide the most comprehensive COI data set so far examined for the Order (1572 sequences of 528 species, 213 genera, and 67 families). Patterns within families show a general predicted molecular hierarchy, but the scale of divergence at each taxonomic level appears to vary extensively between families. The range values of mean K2P distance observed were: within species 0.285% to 1.375%, within genus 6.376% to 20.924% and within family 11.392% to 25.617%. Nucleotide composition varied greatly across decapods, ranging from 30.8 % to 49.4 % GC content. Conclusions/Significance: Decapod biological diversity was quantified by identifying putative cryptic species allowing a rapid assessment of taxon diversity in groups that have until now received limited morphological and systematic examination. We highlight taxonomic groups or species with unusual nucleotide composition or evolutionary rates. Such data are relevant to strategies for conservation of existing decapod biodiversity, as well as elucidating the mechanisms and constraints shaping the patterns observed.FCT - SFRH/BD/25568/ 2006EC FP6 - GOCE-CT-2005-511234 HERMESFCT - PTDC/MAR/69892/2006 LusomarBo

    Experimentações no apoio a partir das apostas da Política Nacional de Humanização - HumanizaSUS

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    Este texto busca narrar e refletir sobre algumas experimentações de apoio institucional, tal como propõe a Política Nacional de Humanização da Atenção e Gestão – HumanizaSUS do Ministério da Saúde, Brasil. O apoio é tomado como método para estranhar relações, saberes, práticas e modos já naturalizados de olhar para o cotidiano do Sistema Único de Saúde. Para tanto, apresenta-se uma contextualização breve sobre a Política Nacional de Humanização e depois algumas situações de apoio são problematizadas para indicar os desafios enfrentados no processo de produção de mudanças na atenção e gestão no Sistema Único de Saúde
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