2,344 research outputs found

    Antoine Desemberg, L’honneur des universitaires au Moyen Âge: Étude d’imaginaire social

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    No dia 1 de dezembro de 2010, Antoine Destemberg defendia a sua tese de doutoramento na Universidade de Paris – Panthéon-Sorbonne, centrada na história da instituição universitária parisiense no período medieval (entre os séculos XIII e XV). Na obra defendia a formação de um grupo individualizado e autónomo, com uma identidade bem definida, procedendo à descrição e caracterização pormenorizada dos seus elementos constituintes (professores, escolares e oficiais), das relações com os vários pod..

    Synergistic Effects of Ocean Warming and Cyanide Poisoning in an Ornamental Tropical Reef Fish

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    UIDP/50017/2020 UIDB/50017/2020 UID/MAR/04292/2019 SFRH/BPD/117491/2016 SFRH/BPD/115298/2016 SFRH/BPD/99819/2014 PD/BD/52568/2014An array of anthropogenic pressures is affecting tropical ecosystems, posing major conservation challenges for scientists, stakeholders and populations. Illegal cyanide fishing is one of the major threats to Indo-Pacific coral reefs, targeting a multitude of colorful species for the marine aquarium trade as well as large-sized groupers and wrasses for the food fish trade. Ultimately, the continued use of this destructive practice as oceans warm may overload tropical ecosystems and result in irreversible ecological damage. Here we show that the impact of cyanide poisoning in an ornamental tropical marine fish is magnified under increased temperatures. A sole pulse exposure of 60 s to 50 mg L–1 of cyanide under current temperature (26°C) caused substantial mortality (50–100%) in eight species of Pomacentridae. The clownfish Amphiprion ocellaris was the most resistant, especially medium-sized fish [average total length and weight of 38 mm and 1.12 g; LC50 (95% CI) = 50.00 (46.76 − 53.24) mg L–1] that showed shorter recovery times and higher survival rates (%) when compared to small-sized ones [average total length and weight of 25 mm and 0.30 g; LC50 (95% CI) = 28.45 (20.17 − 36.72) mg L–1]. However, when the most resistant size-class was concomitantly exposed to a sub-lethal dosage of cyanide (25 mg L–1 instead of 50 mg L–1) and ocean warming scenarios for 2100 (+3°C and heat wave +6°C), survival rates (%) decreased to 60 and 20%, respectively, and recovery times increased in the worst case scenario. Mortality outbreaks, as well as vulnerability to predation, will likely expand in fish inhabiting coral reefs exposed to cyanide fishing unless stronger conservation measures are taken in tropical reefs to limit this destructive practice now and in the oceans of tomorrow.publishersversionpublishe

    Low f-number microlenses for integration on optical microsystems

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    This paper presents microlenses (MLs) with low f-number made of AZ4562 photoresist for integration on optical microsystems. The fabrication process was based on the thermal reflow and rehydration. Large series of MLs were fabricated with a width of 35 μm, a thickness of 5 μm, and spaced apart by 3 μm. The MLs were fabricated directly on the surface of a die with type n+/p-substrate junction photodiode fabricated in a standard CMOS process. The measured focal length was 49 μm with a tolerance of ±2 μm (maximum error of ±4%), resulting in a numerical aperture of 33.6 × 10-2 (±1.3 × 10-2). The measurements also revealed an f-number of 1.4.This work was sponsored by the Brazilian agency Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) under the grant 400110/2014-8: Ciencia sem Fronteiras, Bolsa Pesquisador Visitante Especial (PVE) 2014. The associate editor coordinating the review of this paper and approving it for publication was Prof. M. Nurul Abedin

    Influence of event duration on automatic wheeze classification

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    Patients with respiratory conditions typically exhibit adventitious respiratory sounds, such as wheezes. Wheeze events have variable duration. In this work we studied the influence of event duration on wheeze classification, namely how the creation of the non-wheeze class affected the classifiers' performance. First, we evaluated several classifiers on an open access respiratory sound database, with the best one reaching sensitivity and specificity values of 98% and 95%, respectively. Then, by changing one parameter in the design of the non-wheeze class, i.e., event duration, the best classifier only reached sensitivity and specificity values of 55% and 76%, respectively. These results demonstrate the importance of experimental design on the assessment of wheeze classification algorithms' performance.publishe

    αvβ3 and α5β1 integrin-specific ligands: From tumor angiogenesis inhibitors to vascularization promoters in regenerative medicine?

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    Integrins are cell adhesion receptors predominantly important during normal and tumor angiogenesis. A sequence present on several extracellular matrix proteins composed of Arg-Gly-Asp (RGD) has attracted attention due to its role in cell adhesion mediated by integrins. The development of ligands that can bind to integrins involved in tumor angiogenesis and brake disease progression has resulted in new investigational drug entities reaching the clinical trial phase in humans. The use of integrin-specific ligands can be useful for the vascularization of regenerative medicine constructs, which remains a major limitation for translation into clinical practice. In order to enhance vascularization, immobilization of integrin-specific RGD peptidomimetics within constructs is a recommended approach, due to their high specificity and selectivity towards certain desired integrins. This review endeavours to address the potential of peptidomimetic-coated biomaterials as vascular network promoters for regenerative medicine purposes. Clinical studies involving molecules tracking active integrins in cancer angiogenesis and reasons for their failure are also addressed.Prémios Santa Casa Neurociências - Prize Melo e Castro for Spinal Cord Injury Research; Portuguese Foundation for Science and Technology [Doctoral fellowship (PD/BDE/127835/2016) to L. A. Rocha; IF Development Grant to A. J. Salgado; national funds through grant TUBITAK/0007/2014]. This article has been developed under the scope of the projects NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER); This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038info:eu-repo/semantics/publishedVersio

    CHARON: Routing in low-density opportunistic wireless sensor networks

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    Combining wireless sensor networks (WSNs) with delay-tolerant networking (DTN) has the potential to extend their use in a multitude of previously impossible applications. However, and despite numerous proposed solutions, there is still wide debate as to how to best route messages in these networks and, more importantly, how to do it in an energy-efficient way. This paper proposes CHARON (Convergent Hybrid-replication Approach to Routing in Opportunistic Networks), an approach that focuses on maximizing efficiency in addition to delivery statistics. CHARON uses delay as a routing metric, and provides basic QoS mechanisms, with both a quasi-single-copy mode for general traffic and a multi-copy mode for urgent data. It also integrates time synchronization and radio power management mechanisms. Simulation results show that it is able to achieve good delivery statistics with lower overhead than comparable solutions

    A fuzzified systematic adjustment of the robotic Darwinian PSO

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    The Darwinian Particle Swarm Optimization (DPSO) is an evolutionary algorithm that extends the Particle Swarm Optimization using natural selection to enhance the ability to escape from sub-optimal solutions. An extension of the DPSO to multi-robot applications has been recently proposed and denoted as Robotic Darwinian PSO (RDPSO), benefiting from the dynamical partitioning of the whole population of robots, hence decreasing the amount of required information exchange among robots. This paper further extends the previously proposed algorithm adapting the behavior of robots based on a set of context-based evaluation metrics. Those metrics are then used as inputs of a fuzzy system so as to systematically adjust the RDPSO parameters (i.e., outputs of the fuzzy system), thus improving its convergence rate, susceptibility to obstacles and communication constraints. The adapted RDPSO is evaluated in groups of physical robots, being further explored using larger populations of simulated mobile robots within a larger scenario

    Anaerobic biodegradability of category 2 animal by-products : methane potential and inoculum source

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    Category 2 animal by-products that need to be sterilized with steam pressure according Regulation (EC) 1774/2002 are studied. In this work, 2 sets of experiments were performed in mesophilic conditions: (i) biomethane potential determination testing 0.5%, 2.0% and 5.0% total solids (TS), using sludge from the anaerobic digester of a wastewater treatment plant as inoculum; (ii) biodegradability tests at a constant TS concentration of 2.0% and different inoculum sources (digested sludge from a wastewater treatment plant; granular sludge from an upflow anaerobic sludge blanket reactor; leachate from a municipal solid waste landfill; and sludge from the slaughterhouse wastewater treatment anaerobic lagoon) to select the more adapted inoculum to the substrate in study. The higher specific methane production was of 317 mL CH4 g−1 VSsubstrate for 2.0% TS. The digested sludge from the wastewater treatment plant led to the lowest lag-phase period and higher methane potential rate.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia. FCT is acknowledged for the financial support given to Tatiana Pozdniakova through the PhD scholarship (SFRH/BD/45144/2008) and Jose Carlos Costa through the grant (SFRH/BDP/48962/2008)

    Quality management practices to direct and control the accomplishment of project objectives in R&D units

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    Projects create value and capabilities for organizations and beneficiaries of their outcomes and must be managed by implementing quality processes to assure an execution compliant with plans, activities, and applicable standards, and to accomplish the defined requirements and objectives in an efficient and effective manner. This study analyzed the frequency of use of quality management practices by companies with R&D units and compared them with project management students expectations of implementing quality project management practices as a professional. The data was collected using an online survey, and twenty-six quality management practices have been analyzed using descriptive and inferential statistics, following standard procedures, and using the Independent-samples T-Test. For twelve out of the twenty-six practices, significant differences have been found between the two samples, five referring to quality planning practices and seven referring to quality control practices. For the twelve quality management practices, project management students had greater expectations of implementing them, in contrast to the actual frequency of use among the surveyed companies. The results can provide inputs to improve project management practices among companies, reinforcing the importance of training and recruiting project management professionals that have the required training, talent, and aligned expectations on how to successfully manage projects.- (undefined

    MicroRNA-21 expression and susceptibility to HPV-induced carcinogenesis - role of microenvironment in K14-HPV16 mice model

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    Aims: Human papillomaviruses (HPVs) are responsible for several types of cancer. K14-HPV16 transgenic mice express the HPV16 early genes, developing multi-step carcinogenesis associated with marked inflammation, as observed in human patients. MicroRNAs (MiRNA) constitute a class of non-coding RNAs that regulate gene expression. In particular, miR-21 has been associated with carcinogenesis. However, little is known about this microRNA in the normal tissue microenvironment and its possible relationship with cancer predisposition. We hypothesized that miR-21 expression influences each tissue's susceptibility to HPV-induced carcinogenesis. Main methods: In order to test this hypothesis, we evaluated miR-21 expression by RT-qPCR in ear and chest skin samples from 24-28 weeks old, female K14-HPV16 transgenic and wild-type mice. Key findings: In wild-type mice (HPV-/-) miR-21 expression was lower in ear skin compared with that of chest skin (p = 0.036). Under the influence of HPV16 oncogenes, transgenic animals (HPV16+/-), developed in situ carcinoma in all ear samples and epidermal hyperplasia in chest samples. These results are consistent with the hypothesis that microRNA expression in the microenvironment of normal tissues may influence HPV-associated carcinogenesis. Furthermore, among transgenic animals, miR-21 expression was lower in in situ carcinoma samples compared with hyperplasia (p = 0043). Significance: This suggests that, despite the well-known role of miR-21 as an oncogene, its anti-inflammatory and immunomodulatory properties may modulate HPV-induced carcinogenesis in a tissue-dependent manner. Further studies are warranted in order to explore the role of microRNAs in tissue susceptibility to carcinogenesis
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