1,454 research outputs found

    Study of the dust produced in rehabilitation works

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    "First International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2019)"Urban rehabilitation is becoming more frequent nowadays. With cities full of falling buildings and no space to build new ones, the only solution is to rehabilitate the existing heritage in order to give new life to the vacant buildings and repopulate the cities. A large amount of the built heritage suffers from advanced degradation, making the recovery, increasing the complexity of the rehabilitation and restoration intervention and implying a highly specialized interdisciplinary component. In this type of works more dust is produced than in a new work. In addition, the origin and composition of existing materials is often unknown and can therefore pose many risks to the health of workers. Meaning, dust is breathable and can remain in the air for a long period of time, being invisible to the naked eye and very light. When a building is being demolishing, the production of dust increases significantly. Depending on the type of materials to demolish, the risk of occupational diseases, or risks, to the health of workers may be great. To avoid such risks, preventive measures must be taken in the execution of the tasks. In this study, the dust of two rehabilitation works in the district of Viana do Castelo was studied through experimental tests in order to verify the composition of the demolished materials. Particles characterization was done, using scanning electron microscopy (SEM). Then, with the tests results, the chemical composition of the existing materials was analyzed in detail. After that, the chemical components of demolished materials were carefully studied to identify which of these particles could represent a risk to the workers? health. As a conclusion the preventive measures that workers must take when performing rehabilitation works are presented, depending on what type of materials they are potentially exposed.(undefined

    Surface functionalization of cuttlefish bone-derived biphasic calcium phosphate scaffolds with polymeric coatings

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    Cuttlefish bone (CB) has been explored as biomaterial in the bone tissue-engineering field due to its unique porous structure and capacity of the aragonite mineral to be hydrothermally converted into calcium phosphates (CaPs). In the present study, undoped and ion (Sr2+, Mg2+ and/or Zn2+) doped biphasic calcium phosphate (BCP) scaffolds were prepared by hydrothermal transformation (HT, 200 °C, 24 h) of CB. The obtained scaffolds were sintered and then coated with two commercial polymers, poly(Δ-caprolactone) (PCL) or poly(DL-lactide) (PDLA), and with two synthesized ones, a poly(ester amide) (PEA) or a poly(ester urea) (PEU) in order to improve their compressive strength. The scaffolds were characterized by X-ray diffraction (XRD) coupled with structural Rietveld refinement, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The results demonstrate that CB could be entirely transformed into BCPs in the presence or absence of doping elements. The initial CB structure was preserved and the polymeric coatings did not jeopardize the interconnected porous structure. Furthermore, the polymeric coatings enhanced the compressive strength of the scaffolds. The in vitro bio-mineralization upon immersing the scaffolds into simulated body fluid (SBF) demonstrated the formation of bone-like apatite surface layers in both uncoated and coated scaffolds. Overall, the produced scaffolds exhibit promising properties for bone tissue engineering applications.publishe

    Detection of RHDV strains in the Iberian hare (Lepus granatensis): earliest evidence of rabbit lagovirus cross-species infection

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.Rabbit hemorrhagic disease virus (RHDV) is a highly lethal Lagovirus, family Caliciviridae, that threatens European rabbits (Oryctolagus cuniculus). Although a related virus severely affects hares, cross-species infection was only recently described for new variant RHDV in Cape hares (Lepus capensis mediterraneus). We sequenced two strains from dead Iberian hares (Lepus granatensis) collected in the 1990s in Portugal. Clinical signs were compatible with a Lagovirus infection. Phylogenetic analysis of the complete capsid gene positioned them in the RHDV genogroup that circulated on the Iberian Peninsula at that time. This is the earliest evidence of RHDV affecting a species other than European rabbits.This work was supported by FCT (Fundação para a CiĂȘncia e a Tecnologia; research project ref.: FCT-ANR/BIABIC/0043/2012). FCT also supported the doctoral grants of AML and AP (refs.: SFRH/BD/78738/2011 and SFRH/BD/71252/2010) and the FCT Investigator grant of JA (ref.: IF/01396/2013). “Genomics Applied To Genetic Resources” co-financed by North Portugal Regional Operational Programme 2007/2013 (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF), also supported this work.Peer Reviewe

    Coniferous bark hot steam treatment for the elimination of the pinewood nematode

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    In order to develop an artificial heat treatment to eliminate the pinewood nematode (PWN), Bursaphelenchus xylophilus, from coniferous bark, an industrial equipment, based on hot steam was build up which enables continuous bark treatment for more than 30 min with temperatures above 80ÂșC. Biological assays were performed using experimental units (bags) with Pinus pinaster bark and wood chips containing more than 100 000 PWN (.60% third dispersal juvenile s tage). The bags were heat treated for 30 min and the temperature inside monitored by temperature probes. The total number of live nematodes was quantified immediately after treatment and after incubation (25ÂșC for 15 days) and in both situations no nematodes were detected revealing efficacy in eliminating PWN from coniferous bark

    Implications of a defined daily dose fixed database for drug utilization research studies: The case of statins in Portugal

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    Aims Given the discrepancies between PDDs (prescribed daily doses) and DDDs (defined daily doses), we aimed to assess the extent of error in the results of an 18-year population-level study on statin utilization in Portugal. Methods The Portuguese regulatory agency provided data for the period 2000-2018 on statin dispensing (C10AA). The DDDs were gathered from the ATC/DDD database. DDDs were calculated by the DDD year-by-year approach (DDDYEAR) and by the DDD last-year approach (DDDLAST). PDDs were calculated according to the year-by-year approach (PDDYEAR). Statin annual utilization rates per 1000 inhabitants per day were also calculated. Percent errors were calculated for PDDYEAR and DDDYEAR units. Results The DDDYEAR approach revealed decreases in the consumption of atorvastatin, fluvastatin, lovastatin, pravastatin and simvastatin in 2009, when their DDD was modified. Conversely, the results from both DDDLAST and PDDYEAR approaches indicated gradual changes in the actual consumption of all statins in Portugal. Before 2009, atorvastatin, pravastatin and simvastatin utilization was greatly overestimated by DDDYEAR/1000 inhabitants/day. The average dose of lovastatin prescribed in the past 18 years (20 mg) was below the assigned DDDs during the study period, varying from 30 mg to 45 mg. Conversely, the PDD for fluvastatin was above the DDD values (ranging from 40 mg in 2000 to 70 mg in 2016). For atorvastatin, pravastatin and simvastatin, national PDDs were above the assigned DDD until the DDD modification in 2009. Conclusions A more dynamic system, based on national and annually updated DDDs, should be able to reduce discrepancies between DDDs and PDDs and the bias in utilization studies

    Networking to death: On the dark side of start-ups’ external networking

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    Purpose – Many start-ups do not survive the first few years of business. Previous studies suggest that networks play a role in start-ups’ success, but this positive effect has limits. The purpose of this paper is to answer the call for a better understanding of the dark side of networks and the variables that condition variables’ effect on the likelihood of start-ups’ survival. Design/methodology/approach –Alongitudinal research design includes 139 start-ups (102 from Germany and 37 from Portugal) and a total of 252 participants. A generalized linear mixed model (GLMM)was applied to estimate all the coefficients, to test the mediation (H1), the moderation (H2) and the moderated mediation (H3) while considering the economic situation of the start-up (sales growth), start-ups’ networking behavior, creativity orientation and ultimately the likelihood of survival. Findings – Based on an empirical study from two different countries, the results show that effective networking is contingent on the start-up’s economic situation and creative potential. Specifically, the results point to situations in which early sales growth may lead to external networking, which, in contexts of low creativity-oriented start-ups, can compromise the start-ups’ success. Originality/value – Based on the findings, the authors compare scenarios in which networking increases the chances for start-up survival with situations where networking can have adverse effects. This study highlights the importance of considering specific start-up parameters, such as start-ups’ economic situation and level of creativity orientation, in the business venturing literature.info:eu-repo/semantics/publishedVersio

    InstalaçÔes para manutenção e desenvolvimento de matrizes de Batata-doce com alta sanidade.

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    Spatial and temporal variability in coccolithophore abundance and distribution in the NW Iberian coastal upwelling system

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    A systematic investigation of the spatial and temporal variability in coccolithophore abundance and distribution through the water column of the NW Iberian coastal up-welling system was performed. From July 2011 to June 2012, monthly sampling at various water depths was conducted at two parallel stations located at 42 degrees N. Total coccosphere abundance was higher at the outer-shelf station, where warmer, nutrient-depleted waters favoured coccolithophore rather than phytoplanktonic diatom blooms, which are known to dominate the inner-shelf location. In seasonal terms, higher coccosphere and coccolith abundances were registered at both stations during upwelling seasons, coinciding with high irradiance levels. This was typically in conjunction with stratified, nutrient-poor conditions (i.e. relaxing upwelling conditions). However, it also occurred during some upwelling events of colder, nutrient-rich subsurface waters onto the continental shelf. Minimum abundances were generally found during downwelling periods, with unexpectedly high coccolith abundance registered in subsurface waters at the inner-shelf station. This finding can only be explained if strong storms during these downwelling periods favoured resuspension processes, thus remobilizing deposited coccoliths from surface sediments, and hence hampering the identification of autochthonous coccolithophore community structure. At both locations, the major coccolithophore assemblages were dominated by Emiliania huxleyi, small Gephyrocapsa group, Gephyrocapsa oceanica, Florisphaera profunda, Syracosphaera spp., Coronosphaera mediterranea, and Calcidiscus leptoporus. Ecological preferences of the different taxa were assessed by exploring the relationships between environmental conditions and temporal and vertical variability in coccosphere abundance. These findings provide relevant information for the use of fossil coccolith assemblages in marine sediment records, in order to infer past environmental conditions, of particular importance for Paleoceanography. Both E. huxleyi and the small Gephyrocapsa group are proposed as proxies for the upwelling regime with a distinct affinity for different stages of the upwelling event: E. huxleyi was associated with warmer, nutrient-poor and more stable water column (i.e. upwelling relaxation stage) while the small Gephyrocapsa group was linked to colder waters and higher nutrient availability (i.e. early stages of the upwelling event), similarly to G. oceanica. Conversely, F. profunda is suggested as a proxy for the downwelling regime and low-productivity conditions. The assemblage composed by Syracosphaera pulchra, Coronosphaera mediterranea, and Rhabdosphaera clavigera may be a useful indicator of the presence of subtropical waters conveyed northward by the Iberian Poleward Current. Finally, C. leptoporus is proposed as an indicator of warmer, saltier, and oligotrophic waters during the downwelling/winter regime.EXCAPA project - Xunta de Galicia [10MDS402013PR]; CALIBERIA project (Fundacao para a Ciencia e a Tecnologia - Portugal) [PTDC/MAR/102045/2008]; CALIBERIA project [COMPETE/FEDER-FCOMP-01-0124-FEDER-010599, BI/PTDC/MAR/102045/2008/2010-016, BI/PTDC/MAR/102045/2008/2010-022, BI/PTDC/MAR/102045/2008/2011-027]; Ministerio de Economia y Competitividad [CGL2015-68459-P]; Ministry of Education of Spain [AP2010-2559]; ETH Zurich Postdoctoral Fellowship from the Swiss Federal Institute of Technology in Zurich (ETHZ); Xunta de Galicia (Spain); FCT [SFRH/BPD/111433/2015]; Plurianual/Estrategico project [UID/Multi/04326/2013]info:eu-repo/semantics/publishedVersio
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