1,306 research outputs found

    Important amino acid residues of potato plant uncoupling protein (StUCP)

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    Chemical modifications were used to identify some of the functionally important amino acid residues of the potato plant uncoupling protein (StUCP). The proton-dependent swelling of potato mitochondria in K+-acetate in the presence of linoleic acid and valinomycin was inhibited by mersalyl (Ki = 5 µM) and other hydrophilic SH reagents such as Thiolyte MB, iodoacetate and 5,5'-dithio-bis-(2-nitrobenzoate), but not by hydrophobic N-ethylmaleimide. This pattern of inhibition by SH reagents was similar to that of brown adipose tissue uncoupling protein (UCP1). As with UCP1, the arginine reagent 2,3-butadione, but not N-ethylmaleimide or other hydrophobic SH reagents, prevented the inhibition of StUCP-mediated transport by ATP in isolated potato mitochondria or with reconstituted StUCP. The results indicate that the most reactive amino acid residues in UCP1 and StUCP are similar, with the exception of N-ethylmaleimide-reactive cysteines in the purine nucleotide-binding site.1413142

    Large random simplicial complexes, I

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    In this paper we introduce a new model of random simplicial complexes depending on multiple probability parameters. This model includes the well-known Linial - Meshulam random simplicial complexes and random clique complexes as special cases. Topological and geometric properties of a multi-parameter random simplicial complex depend on the whole combination of the probability parameters and the thresholds for topological properties are convex sets rather than numbers (as in all previously known models). We discuss the containment properties, density domains and dimension of the random simplicial complexes.Comment: 21 pages, 6 figure

    Hardwood and softwood lignins from sulfite liquors: structural characterization and valorization through depolymerization

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    This work aims to evaluate the structural characteristics and study the oxidative depolymerization of lignins obtained from hardwood and softwood sulfite liquors. Lignins were obtained after ultrafiltration and freeze- drying of the sulfite liquors and characterized based on inorganic content, nitrobenzene oxidation, 13C NMR, and molecular weight determination. The structural characteristics achieved allow evaluating the potential of each lignin through oxidative depolymerization to produce added-value phenolic monomers. Hardwood and softwood lignins were submitted to alkaline oxidation with oxygen and the reaction conditions optimized to obtain a final oxidation mixture with the maximum yield of phenolic monomers. Through oxidation with O2, hardwood lignin generates mostly syringaldehyde while lignin from softwood biomass mainly produces vanillin; moreover, a lower reaction time and the interruption of O2 admission avoid the degradation of the oxidation products in the final mixture for both lignins, more evidenced to hardwood lignin due to its higher reactivity. From the results, it is possible to conclude that a phenolic aldehyde-rich oxidation mixture could be obtained, confirming the viability of lignin as raw material to produce added-value products as vanillin and syringaldehyde.This work was financially supported by LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM), funded by national funds through FCT/MCTES (PIDDAC); Base Funding - UIDB/00690/2020 of CIMO - Centro de Investigação de Montanha - funded by national funds through FCT/MCTES (PIDDAC); COST Action LignoCOST (CA17128). Carlos Vega-Aguilar thanks the Costa Rican Science, Technology and Telecommunications Ministry for the PhD. Scholarship MICITT-PINN-CON-2-1-4-17-1-002. Authors are grateful to Company A and Caima - Indústria de Celulose, S.A. (Portugal) for the supply of the samples of sulfite liquorinfo:eu-repo/semantics/publishedVersio

    Kinetics of oxidative degradation of lignin-based phenolic compounds in batch reactor

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    Vanillin, vanillic acid, acetovanillone, syringaldehyde, syringic acid, and acetosyringone are products obtained from lignin oxidation in an alkaline medium. The evaluation of their individual degradation under oxidation conditions mimicking lignin oxidation is an important tool to better understand this reaction and maximize the yield of target value-added products. In this context, the main objective of the present work was to study the kinetics of degradation of the selected ligninbased phenolic compounds. The effect of temperature, initial concentration, and oxygen partial pressure was evaluated, and a simple mathematical model was developed to describe the data from the degradation of the phenolics during oxidation reactions. The results indicate that, for all the evaluated compounds, the reaction order is first order with respect to both the initial phenolic compound concentration and oxygen concentration. A high degradation rate was found for the reactions performed at 413 K, and an activation energy in the range of 53−86 kJ/mol was found for all the studied phenolic compounds. Moreover, syringic acid is the phenolic compound more prone to degradation, while vanillin is the less one.This work is a result of Project “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); Associate Laboratory LSRE-LCM-UID/EQU/50020/2019 - funded by national funds through FCT/MCTES (PIDDAC) and Foundation for Science and Technology (FCT, Portugal). CIMO (UID/AGR/00690/2019) through FEDER under Program PT2020.info:eu-repo/semantics/publishedVersio

    Impact of smoke-free policies in hospitality venues and the home environment on smoking behaviour and exposure to second-hand smoke:Results of two systematic reviews

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    Background Smoke-free policies (SFPs) have proven to be effective in protecting people from exposure to second-hand smoke (SHS) and lowering smoking rates. Our aims were to assess the impact of SFPs in hospitality venues (e.g. bars) on smoking behaviour of young people and to assess the impact of SFPs in the home environment on smoking behaviour and exposure to SHS. Methods Two reviews were conducted. The first was conducted in June 2020. We searched PubMed, Embase, and Scopus for studies that assessed the association between any form of SFPs in hospitality venues and a measure of smoking behaviour among young people (aged 10-24 years). The second review will be conducted in June 2022. Searches will be conducted in PubMed, Embase, Web of Science, PsycINFO and CENTRAL. We will search for studies that assess the association between any form of SFPs in the home environment (e.g. multi-unit housing) and a measure of smoking behaviour (e.g. initiation) or SHS exposure. Results Nine studies (publication years 2005-2016) were included in the first review, of which the majority used a quasi-experimental design. Four studies evaluated SFPs in hospitality venues specifically. Two studies reported that strict, but not weaker, SFPs decrease progression to established smoking. Two other studies provided mixed results. Five studies also included other workplaces, of which three studies found significant decreases in current smoking, smoking frequency, and/or smoking quantity. The results of the second review will be presented in detail during the workshop, however an exploration suggests that SFPs in the home environment may prevent smoking and SHS exposure. Conclusions Most studies of the first review found that SFPs in hospitality venues are associated with a decrease in smoking behaviour among young people. Their results indicate the need for strict smoke-free legislation without exemptions. The conclusions of the second review will be presented during the workshop

    In vitro antiatherogenicity of extracts from Halimeda incrassata seaweed: antioxidant activity and smooth muscle cell migration studies

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    Aim: The aim of this work was to evaluate the in vitro atheroprotective potential of the seaweed Halimeda incrassata in smooth muscle cell migration and lipoprotein oxidation in relation to its antioxidant activity. Material and methods: Antioxidant activity was determinate by DPPH• radical scavenging assay and ORAC method. The inhibitory effect of the aqueous extract on LDL oxidation mediated by Cu2+ ions was determinate by TBARS and conjugated diene quantification. The effect of the seaweed aqueous extract on smooth muscle cell migration was evaluated in MOVAS-1 mouse aortic smooth muscle cell. Results: The inhibitory effect of the aqueous extract on lipoprotein oxidation mediated by Cu2+ was demonstrated. Seaweed extract caused dose-dependent inhibition of TBARS (IC50 = 0.8 mg/mL) and conjugated dienes formation. The seaweed had a high antioxidant activity in the assays performed. The activity could be related to the phenolic content of Halimeda incrassata. Conclusions: In summary, the results of this study represent a further step in the characterization of the atheroprotective action of Halimeda incrassata and indicate the seaweed could be used for a nutraceutical and/or phytoterapeutic application.Objetivos: El objetivo de este trabajo fue evaluar el potencial ateroprotector in vitro del alga Halimeda incrassata en la migración de células de músculo liso de ratón y la oxidación de lipoproteínas en relación con su actividad antioxidante. Material y métodos: La actividad antioxidante fue determinada mediante los métodos de inhibición de radicales DPPH y la Capacidad antioxidante total (ORAC). La actividad inhibitoria de la oxidación de LDL mediada por iones Cu2+ se determinó por la cuantificación de TBARS y dienos conjugados. El efecto del extracto acuoso sobre la migración de las células de músculo liso se evaluó en la línea de células de músculo liso aórtica de ratón MOVAS-1. Resultados: Se demostró el efecto inhibidor del extracto sobre la oxidación de LDL mediada por Cu2+. El extracto del alga causa inhibición dosis-dependiente de la formación de TBARS (IC50 = 0,8 mg/mL) y dienos conjugados. Las algas tuvieron una alta actividad antioxidante en los ensayos realizados y podría estar relacionada con el contenido de compuestos fenólicos. Conclusiones: Los resultados de este trabajo representan un paso más en la caracterización de la acción ateroprotectora de Halimeda incrassata y evidencian sus posibles aplicaciones como nutracéutico y/o fitofármaco.The research was funded by IFS grant F/4897-1. Partial funding was also provided by CIHR grant MOP24447, the Canadian Research Chair award (D.B.) and a personal grant from GSEP, offered by the Canadian Bureau for International Education (A.C) and CNPq- (Brasil)

    Intensification of cattle ranching production systems: Socioeconomic and environmental synergies and risks in Brazil

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    Intensification of Brazilian cattle ranching systems has attracted both national and international attention due to its direct relation with Amazon deforestation on the one hand and increasing demand of the global population for meat on the other. Since Brazilian cattle ranching is predominantly pasture-based, we particularly focus on pasture management. We summarize the most recurrent opportunities and risks associated with pasture intensification that are brought up within scientific and political dialogues, and discuss them within the Brazilian context. We argue that sustainable intensification of pasturelands in Brazil is a viable way to increase agricultural output while simultaneously sparing land for nature. Since environmental degradation is often associated with low-yield extensive systems in Brazil, it is possible to obtain higher yields, while reversing degradation, by adopting practices like rotational grazing, incorporation of legumes and integrated crop-livestock-forestry systems. Technical assistance is however essential, particularly for small- and medium-scale farmers. Sound complementary policies and good governance must accompany these measures so that a ‘rebound effect’ does not lead to increased deforestation and other adverse social and environmental impacts. It is also important that animal welfare is not compromised. Although the discussion is presented with respect to Brazil, some aspects are relevant to other developing countries

    Large-scale collective motion of RFGC galaxies

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    We processed the data about radial velocities and HI linewidths for 1678 flat edge-on spirals from the Revised Flat Galaxy Catalogue. We obtained the parameters of the multipole components of large-scale velocity field of collective non-Hubble galaxy motion as well as the parameters of the generalized Tully-Fisher relationship in the "HI line width - linear diameter" version. All the calculations were performed independently in the framework of three models, where the multipole decomposition of the galaxy velocity field was limited to a dipole, quadrupole and octopole terms respectively. We showed that both the quadrupole and the octopole components are statistically significant. On the basis of the compiled list of peculiar velocities of 1623 galaxies we obtained the estimations of cosmological parameters Omega_m and sigma_8. This estimation is obtained in both graphical form and as a constraint of the value S_8=sigma_8(Omega_m/0.3)^0.35 = 0.91 +/- 0.05.Comment: Accepted for publication in Astrophysics and Space Scienc

    Looking at the smoking epidemic through the lens of population pyramids: Sociodemographic patterns of smoking in Italy, 1983 to 2005

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    Background: Surveillance systems often present data by means of summary measures, like age-standardised rates. In this study, we aimed at comparing information derived from commonly used measures of smoking with that presented in modified population pyramids (PPs), using the example of the diffusion of smoking in Italy over the past two decades.Methods: Data were derived from four National Health Interview Surveys carried out in 1983, 1990 to 1991, 1999 to 2000, and 2004 to 2005. After computing both age-specific and age-standardised rates of current, former, and never smoking, we constructed modified PPs by stratifying the male and female populations according to smoking status and educational level.Results: Modified PPs showed several features of the smoking epidemic in Italy that were not apparent from conventional surveillance techniques. First, they showed that the population of smokers is aging, with most current smokers in 2005 being males aged 25 to 39 and females aged 40 to 49, whereas in 1983 most smokers belonged to the youngest age groups. Second, they showed that in 2005 most smokers were found among subjects with middle and higher education, whereas two decades earlier most smokers were (male) subjects with the lowest education.Conclusions: Modified PPs were able to show how absolute numbers of smokers were distributed by age and sex, how these numbers varied between population subgroups, and how they changed over time. PPs may help provide information on past and future trends in the absolute number of smokers and in their sociodemographic characteristics, which may be missed using only traditional surveillance methods
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