3,319 research outputs found

    The information systems accounting – a literature review

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    This paper was written with the intention of reviewing literature on the subject of information systems costing revealing existing gaps. More precisely, it summarizes content found on this subject. Costing reduction has been under focus by organizations, especially after the global crisis in the last decade. To reduce costs it is crucial to perform an accurate measurement. As investment in IT has grown over the years, so have IT costs. However, literature does not seem to show these growing worries. Research on this subject shows some flaws that are discussed and exposed in this paper.info:eu-repo/semantics/acceptedVersio

    An open and parallel multiresolution framework using block-based adaptive grids

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    A numerical approach for solving evolutionary partial differential equations in two and three space dimensions on block-based adaptive grids is presented. The numerical discretization is based on high-order, central finite-differences and explicit time integration. Grid refinement and coarsening are triggered by multiresolution analysis, i.e. thresholding of wavelet coefficients, which allow controlling the precision of the adaptive approximation of the solution with respect to uniform grid computations. The implementation of the scheme is fully parallel using MPI with a hybrid data structure. Load balancing relies on space filling curves techniques. Validation tests for 2D advection equations allow to assess the precision and performance of the developed code. Computations of the compressible Navier-Stokes equations for a temporally developing 2D mixing layer illustrate the properties of the code for nonlinear multi-scale problems. The code is open source

    Ashbya gossypii beyond industrial riboflavin production: a historical perspective and emerging biotechnological applications

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    The filamentous fungus Ashbya gossypii has been safely and successfully used for more than two decades in the commercial production of riboflavin (vitamin B2). Its industrial relevance combined with its high genetic similarity with Saccharomyces cerevisiae together promoted the accumulation of fundamental knowledge that has been efficiently converted into a significant molecular and in silico toolbox for its genetic engineering. This synergy has enabled a directed and sustained exploitation of A. gossypii as an industrial riboflavin producer. Although there is still room for optimizing riboflavin production, the recent years have seen an abundant advance in the exploration of A. gossypii for other biotechnological applications, such as the production of recombinant proteins, single cell oil and flavour compounds. Here, we will address the biotechnological potential of A. gossypii beyond riboflavin production by presenting (a) a physiological and metabolic perspective over this fungus; (b) the molecular toolbox available for its manipulation; and (c) commercial and emerging biotechnological applications for this industrially important fungus, together with the approaches adopted for its engineering.The authors thank the financial support from the Fundacao para a Ciencia e a Tecnologia (FCT), Portugal, through the Strategic Project of UID/BIO/04469/2013 unit (Post-Doc fellowship UMINHO/BPD/36/2015 to T. Q. Aguiar), the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF. NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER

    Translocating the blood-brain barrier using electrostatics

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    Copyright © 2012 Ribeiro,Domingues, Freire,Santos and Castanho. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.Mammalian cell membranes regulate homeostasis, protein activity, and cell signaling. The charge at the membrane surface has been correlated with these key events. Although mammalian cells are known to be slightly anionic, quantitative information on the membrane charge and the importance of electrostatic interactions in pharmacokinetics and pharmacodynamics remain elusive. Recently, we reported for the first time that brain endothelial cells (EC) are more negatively charged than human umbilical cord cells, using zeta-potential measurements by dynamic light scattering. Here, we hypothesize that anionicity is a key feature of the blood-brain barrier (BBB) and contributes to select which compounds cross into the brain. For the sake of comparison, we also studied the membrane surface charge of blood components—red blood cells (RBC), platelets, and peripheral blood mononuclear cells (PBMC).To further quantitatively correlate the negative zeta-potential values with membrane charge density, model membranes with different percentages of anionic lipids were also evaluated. From all the cells tested, brain cell membranes are the most anionic and those having their lipids mostly exposed, which explains why lipophilic cationic compounds are more prone to cross the blood-brain barrier.Fundação para a Ciência e Tecnologia — Ministério da Educação e Ciência (FCT-MEC, Portugal) is acknowledged for funding (including fellowships SFRH/BD/42158/2007 to Marta M.B. Ribeiro, SFRH/BD/41750/2007 to Marco M. Domingues and SFRH/BD/70423/2010 to João M. Freire) and project PTDC/QUI-BIQ/119509/2010. Marie Curie Industry-Academia Partnerships and Pathways (European Commission) is also acknowledged for funding (FP7-PEOPLE-2007-3-1-IAPP, Project 230654)

    Thymus citriodorus: phenolic characterization and antioxidant activity

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    The present work aims to determine the phenolic composition of Thymus citriodorus and to estimate its antioxidant capacity. An ethanolic extract was prepared from the plant and its total phenolic and flavone contents were determined. The phenolic extract was fractionated by reversed-phase HPLC and the major phenolic compounds of each fraction were identified by ESI-MS and MSn analysis, in order to establish the specific phenolic profile of the plant. The total phenolic compounds in the ethanolic extract of Thymus citriodorus accounted for 138,75±13,56 mg/g, and its content of flavones was estimated as 27,30±2,15 mg/g. Moreover, the interpretation of the fragmentation pathways under ESI-MS/MS of the collected HPLC fractions allowed concluding that the major phenolic compounds in the plant included some glycoside derivatives of luteonin, naringenin and eriodictyol. Also, the phenolic extract showed a considerable antioxidant activity, as evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging potential and the reducing potential, suggesting that Thymus citriodorus can be an important source of natural antioxidants

    Avaliação termográfica de instalações de refrigeração

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    Numa sociedade em que a utilização racional de energia constitui cada vez mais uma prioridade, é pertinente a avaliação do desempenho energético dos equipamentos que actualmente se encontram em funcionamento nas diferentes instalações industriais e agro-industriais. Em particular, no distrito de Castelo Branco existem várias empresas que utilizam o “Frio” como parte do seu processo produtivo ou como método de conservação de produtos e que contribuem para o epíteto “Castelo Branco, Capital do Frio”. No presente estudo efectua-se um diagnóstico energético das câmaras frigoríficas com recurso à Termografia por Infravermelhos (TIV)

    Mentha aquatica: source of flavanone glycosides

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    Mentha aquatica L., commonly known as water mint, is a perennial herb that grows in Europe temperate regions. This plant is used in traditional medicine for the treatment of external inflammation, rheumatism, colds, respiratory problems and difficult menstruation [1]. It has been described as a good source of phenolic compounds with high scavenger activity [2]. In this study, a purified ethanolic extract of M. aquatica was prepared and its specific phenolic composition was determined. The extract of the aerial parts of M. aquatica was prepared according the procedure described by Pereira et al [3] and analyzed by high performance liquid chromatography with diode array detection with quantification of main phenolic compounds, using the external standard method. In order to determine the exact structure of phenolic compounds, the HPLC eluted fractions were manually collected and further analyzed by tandem electrospray mass spectrometry. The purified ethanolic extract of M. aquatica was mainly rich in flavanones comprises eriodictyol, hesperitin and naringenin glycosides. Moreover, the purified ethanolic extract of M. aquatica contained moderate amounts of rosmarinic acid, a phenolic acid very common in Mentha species and in Lamiaceae family

    Insect detection in sticky trap images of tomato crops using machine learning

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    As climate change, biodiversity loss, and biological invaders are all on the rise, the significance of conservation and pest management initiatives cannot be stressed. Insect traps are frequently used in projects to discover and monitor insect populations, assign management and conservation strategies, and assess the effectiveness of treatment. This paper assesses the application of YOLOv5 for detecting insects in yellow sticky traps using images collected from insect traps in Portuguese tomato plantations, acquired under open field conditions. Furthermore, a sliding window approach was used to minimize insect detection duplicates in a non-complex way. This article also contributes to event forecasting in agriculture fields, such as diseases and pests outbreak, by obtaining insect related metrics that can be further analyzed and combined with other data extracted from the crop fields, contributing to smart farming and precision agriculture. The proposed method achieved good results when compared to related works, reaching 94.4% for mAP_0.5, with a precision and recall of 88% and 91%, respectively, using YOLOv5x.info:eu-repo/semantics/publishedVersio
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