661 research outputs found

    Absolute quantification of the host-to-parasite DNA ratio in Theileria parva-infected lymphocyte cell lines

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    Theileria parva is a tick-transmitted intracellular apicomplexan pathogen of cattle in sub-Saharan Africa that causes East Coast fever (ECF). ECF is an acute fatal disease that kills over one million cattle annually, imposing a tremendous burden on African small-holder cattle farmers. The pathology and level of T. parva infections in its wildlife host, African buffalo (Syncerus caffer), and in cattle are distinct. We have developed an absolute quantification method based on quantitative PCR (qPCR) in which recombinant plasmids containing single copy genes specific to the parasite (apical membrane antigen 1 gene, ama1) or the host (hypoxanthine phosphoribosyltransferase 1, hprt1) are used as the quantification reference standards. Our study shows that T. parva and bovine cells are present in similar numbers in T. parva-infected lymphocyte cell lines and that consequently, due to its much smaller genome size, T. parva DNA comprises between 0.9% and 3% of the total DNA samples extracted from these lines. This absolute quantification assay of parasite and host genome copy number in a sample provides a simple and reliable method of assessing T. parva load in infected bovine lymphocytes, and is accurate over a wide range of host-to-parasite DNA ratios. Knowledge of the proportion of target DNA in a sample, as enabled by this method, is essential for efficient high-throughput genome sequencing applications for a variety of intracellular pathogens. This assay will also be very useful in future studies of interactions of distinct host-T. parva stocks and to fully characterize the dynamics of ECF infection in the field

    Overview of mining residues incorporation in construction materials and barriers for full-scale application

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    This work has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 778045, as well as from Portuguese funds from FCT/MCTES through grant UID/AMB/04085/2019. J. Almeida acknowledges Fundação para a Ciência e a Tecnologia for her PhD fellowship 560 PD/BD/135170/2017.Resources efficiency regarding the decrease of residues generation and disposal are important steps towards a cleaner production in the construction and mining industry. Minning processes generate huge amounts of residues, and some deposits have accumulated them over hundreds of years, causing environmental and public health problems. However, mining residues can be recovered as secondary supplies for construction materials production due to its physical, chemical and microstructural properties. This study presents a critical review on sustainable strategies researched to introduce mining residues in the construction sector. The gaps and barriers of these strategies and final products are discussed, concerning a safe and sustainable inclusion of mine residues in construction materials productionauthorsversionpublishe

    Environmental benefits and mechanical performance of cement mortars with tungsten mining residues incorporation

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    No. ERC2016-CoG 725034 UID/AMB/04085/2020 PD\BD\135170\2017. TSecondary mining resources have been largely applied for the development of alternative building products. Additionally, its reuse versatility increases the potential on the future circular economy generation. Herein, mining residues from Panasqueira mine were applied in the formulation of cement-based mortars, according to EN 196-1 standard.Mechanical performance of mortars was analysed after the replacement of the conventional binder (cement) by mining residues in 10, 25 and 50 % (v/v). As expected, compressive and flexural strength decrease when compared to the reference mortar (100 % cement) in all cases. This decrease was more significant in terms of compressive strength (between 27 % and 71 %), when compared to flexural strength results (between 18 % and 56 %). Furthermore, an environmental approach of secondary mining resources incorporation on mortars, regarding Portugal and Poland data, was carried out. The savings in terms of primary resources may promote to minimise energy impacts. When mining residues replace cement in 10 % is possible to save 0.3 or 1.9 Mt of cement production and 0.14 or 0.89 CO2 Mt emissions, in Portugal and Poland, respectively.publishersversionpublishe

    Effect of mining residues treated with an electrodialytic technology on cement-based mortars

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    UIDB/04085/2020 PD/BD/135170/2017Mining residues have been accumulated for centuries due to excavation and mining processes, causing environmental degradation worldwide. Their application in cementitious products is a feasible alternative to waste disposal. Electrodialytic technologies can promote a safer reuse of mining residues in the construction sector, coupling economic advantages due to the possible removal of toxic elements and the recovery of critical raw materials. The application of treated mining residues in construction products, namely their effects on physico-mechanical properties, in comparison to raw residues and cement uses needs to be addressed. This work presents a study of cement-based mortars with the incorporation of mining residues treated with an electrodialytic process in comparison to raw mining residues. The replacement percentages studied were 0, 10, 25 and 50 % of the binder in volume. Tests were conducted to evaluate fresh and hardened properties of mortars considering physical, microstructural and mechanical performances. Results show the viability of applying mining residues after the electrodialytic treatment as mortars materials in rendering, plastering, joint repointing, bedding masonry or screed requirements, with improved thermal conductivity and eco-efficiency.proofpublishe

    Energy rehabilitation of Portuguese residential building stock through its transformation into NZEB

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    The first global oil crisis, led the European Union to start the necessary procedures in order to control and reduce the energy consumption of buildings. In Europe the energy consumption of residential buildings increased since 1990 until 2003 1.3% per year and it is expected that, by 2050, the energy consumption of buildings will have increased by 40%. According to the EPBD-recast all member states should adopt the necessary measures so that buildings become highly efficient - nearly Zero Energy Buildings (nZEB’s). Nevertheless, quantitative standards are not appointed, so each member state should establish the minimum requirements for energy performance in buildings attending to the local conditions. However before establishing these requirements it is necessary to evaluate the building stock and its energy efficiency. As most of the Portuguese residential buildings are old and degraded an opportunity arises for the energy rehabilitation of the building stock, implementing EPBD-recast principles, making it more energy efficient and comfortable. The aim of this study was to describe the current conditions of the building stock in order to identify whether there are suitable conditions for energy rehabilitation of buildings. The analysis performed showed that although there are a significant potential for building energy rehabilitation, there are also some constraints, namely the lack of credit and loans financing of banks

    Enquadramento energético do sector residencial português

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    Portugal não possui reservas de energias fósseis, pelo que importa grande parte dos recursos energéticos que consome. Nos últimos anos tem sido feita uma aposta na instalação de sistemas de produção de energia a partir de energias renováveis no sentido de reduzir a dependência energética nacional. Contudo, os níveis de dependência, em 2010, ainda eram muito elevados principalmente devido à importação de petróleo. O sector residencial é o que apresenta o terceiro maior consumo energético. Tendo-se verificado nos últimos anos um aumento crescente dos consumos, em especial de eletricidade. Através da avaliação da tendência de evolução do consumo energético das habitações, é possível determinar qual a melhor forma de reduzir esses consumos aquando da reabilitação energética dos edifícios. O estudo apresentado tem por objetivo analisar os consumos energéticos do sector residencial, de forma a saber em que fatores intervir para aumentar a eficiência energética do parque habitacional Português

    Signature of adaptive evolution in olfactory receptor genes in Cory's Shearwater supports molecular basis for smell in procellariiform seabirds

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    Olfactory receptors (ORs), encoded by the largest vertebrate multigene family, enable the detection of thousands of unique odorants in the environment and consequently play a critical role in species survival. Here, we advance our knowledge of OR gene evolution in procellariiform seabirds, an avian group which relies on the sense of olfaction for critical ecological functions. We built a cosmid library of Cory's Shearwater (Calonectris borealis) genomic DNA, a model species for the study of olfaction-based navigation, and sequence OR gene-positive cosmid clones with a combination of sequencing technologies. We identified 220 OR open reading frames, 20 of which are full length, intact OR genes, and found a large ratio of partial and pseudogenes to intact OR genes (2:1), suggestive of a dynamic mode of evolution. Phylogenetic analyses revealed that while a few genes cluster with those of other sauropsid species in a γ (gamma) clade that predates the divergence of different avian lineages, most genes belong to an avian-specific γ-c clade, within which sequences cluster by species, suggesting frequent duplication and/or gene conversion events. We identified evidence of positive selection on full length γ-c clade genes. These patterns are consistent with a key role of adaptation in the functional diversification of olfactory receptor genes in a bird lineage that relies extensively on olfaction.info:eu-repo/semantics/publishedVersio

    Vulvovaginal candidiasis: Epidemiology, microbiology and risk factors

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    Vulvovaginal candidiasis (VVC) is an infection caused by Candida species that affects millions of women every year. Although Candida albicans is the main cause of VVC, the identification of non-Candida albicans Candida (NCAC) species, especially Candida glabrata, as the cause of this infection, appears to be increasing. The development of VVC is usually attributed to the disturbance of the balance between Candida vaginal colonization and host environment by physiological or nonphysiological changes. Several host-related and behavioral risk factors have been proposed as predisposing factors for VVC. Host-related factors include pregnancy, hormone replacement, uncontrolled diabetes, immunosuppression, antibiotics, glucocorticoids use and genetic predispositions. Behavioral risk factors include use of oral contraceptives, intrauterine device, spermicides and condoms and some habits of hygiene, clothing and sexual practices. Despite a growing list of recognized risk factors, much remains to be elucidated as the role of host versus microorganisms, in inducing VVC and its recurrence. Thus, this review provides information about the current state of knowledge on the risk factors that predispose to VVC, also including a revision of the epidemiology and microbiology of VVC, as well as of Candida virulence factors associated with vaginal pathogenicity.The authors report no declarations of interest. This study was supported by the Programa Operacional, Fatores de competitividade – COMPETE and by national funds through FCT – Fundac¸a ˜o para a Cie ˆncia e a Tecnologia on the scope of the projects FCT PTDC/EBB-EBI/120495/2010, RECI/EBBEBI/0179/2012 and PEst-OE/EQB/LA0023/2013. The authors thank the Project ‘‘BioHealth – Biotechnology and Bioengineering approaches to improve health quality,’’ Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER

    Multiple cell signalling pathways of human proinsulin c-peptide in vasculopathy protection

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    A major hallmark of diabetes is a constant high blood glucose level (hyperglycaemia), resulting in endothelial dysfunction. Transient or prolonged hyperglycemia can cause diabetic vasculopathy, a secondary systemic damage. C-Peptide is a product of cleavage of proinsulin by a serine protease that occurs within the pancreatic -cells, being secreted in similar amounts as insulin. The biological activity of human C-peptide is instrumental in the prevention of diabetic neuropathy, nephropathy and other vascular complications. The main feature of type 1 diabetes mellitus is the lack of insulin and of C-peptide, but the progressive -cell loss is also observed in later stage of type 2 diabetes mellitus. C-peptide has multifaceted effects in animals and diabetic patients due to the activation of multiple cell signalling pathways, highlighting p38 mitogen-activated protein kinase and extracellular signalregulated kinase ½, Akt, as well as endothelial nitric oxide production. Recent works highlight the role of C-peptide in the prevention and amelioration of diabetes and also in organ-specific complications. Benefits of C-peptide in microangiopathy and vasculopathy have been shown through conservation of vascular function, and also in the prevention of endothelial cell death, microvascular permeability, neointima formation, and in vascular inflammation. Improvement of microvascular blood flow by replacing a physiological amount of C-peptide, in several tissues of diabetic animals and humans, mainly in nerve tissue, myocardium, skeletal muscle, and kidney has been described. A review of the multiple cell signalling pathways of human proinsulin C-peptide in vasculopathy protection is proposed, where the approaches to move beyond the state of the art in the development of innovative and effective therapeutic options of diabetic neuropathy and nephropathy are discussed.The authors acknowledge the financial support received from Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project references M-ERA-NET/0004/2015-PAIRED and UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020. The authors acknowledge the support of the research project: Nutraceutica come supporto nutrizionale nel paziente oncologico, CUP: B83D18000140007.info:eu-repo/semantics/publishedVersio
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