249 research outputs found
The evolution of design with concerns on sustainability
This paper aims to analyse the birth and evolution of design with concerns over sustainability, in the context of social and civilizational changes experienced since the industrial revolution, with particular focus since the post-war period and in the context of sustainable development. It will examine several factors that influenced this design approach and that drove its evolution through different stages of maturity and complexity. It will analyse the various forms of design with environmental concerns, as well as the inclusion of other criteria in the context of sustainability, namely social ones. The aim is to settle knowledge that can allow us to draw some lessons to meet the challenges we face today
Heterogeneous Delays in Neural Networks
We investigate heterogeneous coupling delays in complex networks of excitable
elements described by the FitzHugh-Nagumo model. The effects of discrete as
well as of uni- and bimodal continuous distributions are studied with a focus
on different topologies, i.e., regular, small-world, and random networks. In
the case of two discrete delay times resonance effects play a major role:
Depending on the ratio of the delay times, various characteristic spiking
scenarios, such as coherent or asynchronous spiking, arise. For continuous
delay distributions different dynamical patterns emerge depending on the width
of the distribution. For small distribution widths, we find highly synchronized
spiking, while for intermediate widths only spiking with low degree of
synchrony persists, which is associated with traveling disruptions, partial
amplitude death, or subnetwork synchronization, depending sensitively on the
network topology. If the inhomogeneity of the coupling delays becomes too
large, global amplitude death is induced
Identifying disease genes using machine learning and gene functional similarities, assessed through Gene Ontology
Identifying disease genes from a vast amount of genetic data is one of the most challenging tasks in the post-genomic era. Also, complex diseases present highly heterogeneous genotype, which difficult biological marker identification. Machine learning methods are widely used to identify these markers, but their performance is highly dependent upon the size and quality of available data. In this study, we demonstrated that machine learning classifiers trained on gene functional similarities, using Gene Ontology (GO), can improve the identification of genes involved in complex diseases. For this purpose, we developed a supervised machine learning methodology to predict complex disease genes. The proposed pipeline was assessed using Autism Spectrum Disorder (ASD) candidate genes. A quantitative measure of gene functional similarities was obtained by employing different semantic similarity measures. To infer the hidden functional similarities between ASD genes, various types of machine learning classifiers were built on quantitative semantic similarity matrices of ASD and non-ASD genes. The classifiers trained and tested on ASD and non-ASD gene functional similarities outperformed previously reported ASD classifiers. For example, a Random Forest (RF) classifier achieved an AUC of 0. 80 for predicting new ASD genes, which was higher than the reported classifier (0.73). Additionally, this classifier was able to predict 73 novel ASD candidate genes that were enriched for core ASD phenotypes, such as autism and obsessive-compulsive behavior. In addition, predicted genes were also enriched for ASD co-occurring conditions, including Attention Deficit Hyperactivity Disorder (ADHD). We also developed a KNIME workflow with the proposed methodology which allows users to configure and execute it without requiring machine learning and programming skills. Machine learning is an effective and reliable technique to decipher ASD mechanism by identifying novel disease genes, but this study further demonstrated that their performance can be improved by incorporating a quantitative measure of gene functional similarities. Source code and the workflow of the proposed methodology are available at https://github.com/Muh-Asif/ASD-genes-prediction.This work was supported by the Portuguese Fundação para a Ciência e Tecnologia
(SFRH/BD/52485/2014 to MA and DeST: Deep Semantic Tagger PTDC/CCI-BIO/28685/2017).info:eu-repo/semantics/publishedVersio
Cellulose nanofibers produced from banana peel by chemical and mechanical treatments: characterization and cytotoxicity assessment
Cellulose nanoparticles from a vegetable source (cellulose fiber) have been evaluated for future use as reinforcement of polymeric matrixes (e.g., biodegradable films). Cellulose nanoparticles have numerous advantages: they are inexpensive and biodegradable, and they originate from renewable sources. Here, cellulose nanofibers (CNFs) were isolated from banana peel by chemical (alkaline treatment and bleaching followed by acid hydrolysis with 0.1, 1, or 10% (v/v) H2SO4) and mechanical (high pressure homogenizer) treatments. Atomic Force Microscopy (AFM) analysis showed all treatments effectively isolated banana fibers at the nanometer scale (average diameter of 3.72 nm). CNFs displayed -potential values ranging from -37.60 to -67.37 mV, which prevented their aggregation. CNFs had high crystallinity values, from 63.1 to 66.4%, which indicated they could be good reinforcing agents. FTIR results confirmed that the chemical and mechanical treatments removed the amorphous fractions. Regarding cytotoxicity, low CNF concentrations (50-500 g/mL) did not cause cell death, but CNFs at concentrations above 1000 g/mL significantly decreased cell viability. The use of different sulfuric acid concentrations provided more detailed knowledge of the treatment methods and CNF features, which could help to improve the CNF production process. The combination of chemical and mechanical treatments proved to be an efficient strategy to prepare CNFs from banana peels as a potential reinforcing agent of polymeric matrixes (e.g., food packaging).The authors would like to acknowledge the financial support
provided by Coordenaçao de Aperfeiçoamento de Pessoal de Nível ~
Superior (2952/2011), Conselho Nacional de Desenvolvimento Científico e Tecnologico (150523/2013-0 and 140274/2014-6), and
CAPES/FCT 349/13 for the PhD exchange program. Joana T. Martins
acknowledges the Foundation for Science and Technology for her
fellowship (SFRH/BPD/89992/2012). This study was supported by
FCT under the scope of the strategic funding of UID/BIO/04469/
2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and
BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by
the European Regional Development Fund under the scope of
Norte2020 - Programa Operacional Regional do Norte. This study
was also supported by FCT under the scope of the Project RECI/BBBEBI/0179/2012
(FCOMP-01-0124-FEDER-027462). The authors
would also like to acknowledge the Brazilian Nanotechnology National
Laboratory (LNNano) for allocation of the TEM and AFM
apparatus.info:eu-repo/semantics/publishedVersio
Control of a novel chaotic fractional order system using a state feedback technique
We consider a new fractional order chaotic system displaying an interesting behavior. A necessary condition for the system to remain chaotic is derived. It is found that chaos exists in the system with order less than three. Using the Routh-Hurwitz and the Matignon stability criteria, we analyze the novel chaotic fractional order system and propose a control methodology that is better than the nonlinear counterparts available in the literature, in the sense of simplicity of implementation and analysis. A scalar control input that excites only one of the states is proposed, and sufficient conditions for the controller gain to stabilize the unstable equilibrium points derived. Numerical simulations confirm the theoretical analysis. © 2013 Elsevier Ltd. All rights reserved
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
Human Resource Flexibility as a Mediating Variable Between High Performance Work Systems and Performance
Much of the human resource management literature has demonstrated the impact of high performance
work systems (HPWS) on organizational performance. A new generation of studies is
emerging in this literature that recommends the inclusion of mediating variables between HPWS
and organizational performance. The increasing rate of dynamism in competitive environments
suggests that measures of employee adaptability should be included as a mechanism that may
explain the relevance of HPWS to firm competitiveness. On a sample of 226 Spanish firms, the
study’s results confirm that HPWS influences performance through its impact on the firm’s
human resource (HR) flexibility
Bioactivities and extract dereplication of actinomycetales isolated from marine sponges
In the beginning of the twenty-first century, humanity faces great challenges regarding diseases and health-related quality of life. A drastic rise in bacterial antibiotic resistance, in the number of cancer patients, in the obesity epidemics and in chronic diseases due to life expectation extension are some of these challenges. The discovery of novel therapeutics is fundamental and it may come from underexplored environments, like marine habitats, and microbial origin. Actinobacteria are well-known as treasure chests for the discovery of novel natural compounds. In this study, eighteen Actinomycetales isolated from marine sponges of three Erylus genera collected in Portuguese waters were tested for bioactivities with the main goal of isolating and characterizing the responsible bioactive metabolites. The screening comprehended antimicrobial, anti-fungal, anti-parasitic, anti-cancer and anti-obesity properties. Fermentations of the selected strains were prepared using ten different culturing media. Several bioactivities against the fungus Aspergillus fumigatus, the bacteria Staphylococcus aureus methicillin-resistant (MRSA) and the human liver cancer cell line HepG2 were obtained in small volume cultures. Screening in higher volumes showed consistent anti-fungal activity by strain Dermacoccus sp. #91-17 and Micrococcus luteus Berg02-26. Gordonia sp. Berg02-22.2 showed anti-parasitic (Trypanosoma cruzi) and anti-cancer activity against several cell lines (melanoma A2058, liver HepG2, colon HT29, breast MCF7 and pancreatic MiaPaca). For the anti-obesity assay, Microbacterium foliorum #91-29 and #91-40 induced lipid reduction on the larvae of zebrafish (Danio rerio). Dereplication of the extracts from several bacteria showed the existence of a variety of secondary metabolites, with some undiscovered molecules. This work showed that Actinomycetales are indeed good candidates for drug discovery.This research was partially supported by the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT – Foundation for Science and Technology and European Regional Development Fund (ERDF), in the framework of the programme PT2020, the EU H2020-TWINN-2015, BLUEandGREEN – Boosting scientific excellence and innovation capacity in biorefineries based on marine resources (Project No. 692419) and the European ERA-NET Marine Biotechnology project CYANOBESITY (ERA-MBT/0001/2015), financed by national funds through FCT (Foundation for Science and Technology, Portugal). Ralph Urbatzka was supported by a FCT postdoc grant (SFRH/BPD/112287/2015). The MEDINA authors disclosed the receipt of financial support from Fundación MEDINA, a public-private partnership of Merck Sharp & Dohme de España S.A./Universidad de Granada/Junta de Andalucía. Moreover, some of the equipment used in this work was supported by the Ministerio de Ciencia e Innovación and the European Union (Grant INP-2011-0016-PCT-010000-ACT6)
Oral Anticoagulation and Risk of Symptomatic Hemorrhagic Transformation in Stroke Patients Treated With Mechanical Thrombectomy: Data From the Nordictus Registry
Introduction: We aimed to evaluate if prior oral anticoagulation (OAC) and its type determines a greater risk of symptomatic hemorrhagic transformation in patients with acute ischemic stroke (AIS) subjected to mechanical thrombectomy. Materials and
Methods: Consecutive patients with AIS included in the prospective reperfusion registry NORDICTUS, a network of tertiary stroke centers in Northern Spain, from January 2017 to December 2019 were included. Prior use of oral anticoagulants, baseline variables, and international normalized ratio (INR) on admission were recorded. Symptomatic intracranial hemorrhage (sICH) was the primary outcome measure. Secondary outcome was the relation between INR and sICH, and we evaluated mortality and functional outcome at 3 months by modified Rankin scale. We compared patients with and without previous OAC and also considered the type of oral anticoagulants.
Results: About 1.455 AIS patients were included, of whom 274 (19%) were on OAC, 193 (70%) on vitamin K antagonists (VKA), and 81 (30%) on direct oral anticoagulants (DOACs). Anticoagulated patients were older and had more comorbidities. Eighty-one (5.6%) developed sICH, which was more frequent in the VKA group, but not in DOAC group. OAC with VKA emerged as a predictor of sICH in a multivariate regression model (OR, 1.89 [95% CI, 1.01–3.51], p = 0.04) and was not related to INR level on admission. Prior VKA use was not associated with worse outcome in the multivariate regression model nor with mortality at 3 months.
Conclusions: OAC with VKA, but not with DOACs, was an independent predictor of sICH after mechanical thrombectomy. This excess risk was associated neither with INR value by the time thrombectomy was performed, nor with a worse functional outcome or mortality at 3 months
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