2,250 research outputs found
Spatial extremes: Models for the stationary case
The aim of this paper is to provide models for spatial extremes in the case of stationarity. The spatial dependence at extreme levels of a stationary process is modeled using an extension of the theory of max-stable processes of de Haan and Pickands [Probab. Theory Related Fields 72 (1986) 477-492]. We propose three one-dimensional and three two-dimensional models. These models depend on just one parameter or a few parameters that measure the strength of tail dependence as a function of the distance between locations. We also propose two estimators for this parameter and prove consistency under domain of attraction conditions and asymptotic normality under appropriate extra conditions
Dust in Lacquer, Evidence of Deviation of Process in Production Lines for Spray Painting
This paper concerns work carried with a view to reduce defect occurrence rate in the spray painting lines of MDF (medium density fibre cluster-medium density fibreboard) parts of a multinational mobile manufacturing. The determination of the causes for the excessive rejection values is elusive for the multiplicity of factors and parameters involved and the dispersion of application times, not always sufficiently or properly documented. A process analysis methodology was applied to diagnose possible causes of defect occurrences. Considering that the highest defect rate concerned impurities, data collected over a six months’ period was analysed using SPSS to find the correlation between parameters, to find optimal limits of some parameters and evidence of their influence. Kaizen-Lean actions were discussed and implemented conducing to an effective reduction of the existing impurities defect rate, which decreased ninefold related with initial work values.info:eu-repo/semantics/publishedVersio
IN SITU PRESERVATION AND RESTORATION OF ARCHITECTURAL TILES, MATERIALS AND PROCEDURES: RESULTS OF AN INTERNATIONAL SURVEY
In order to aid research, improve preservation actions and develop better options for future interventions it is important to know the preservation materials and procedures adopted throughout the past and especially the ones being adopted nowadays. A survey to specialists
working in situ in preservation and restoration of glazed decorative tiles has been performed aiming at getting insight on their type of training, work portfolio, opinions, the current materials and procedures used in the diverse phases of a preservation intervention (diagnosis, cleaning, consolidation, bonding fragments and fixing of glazed layer, volumetric and chromatic reintegration, final coating, resetting of tiles and manufacture of replicas) and the criteria/factors that support the specialists choices
Endo- and epiphytic fungal communities of olive twigs is influenced by cultivar and olive knot infection
Olive tree phyllosphere is colonized by a diverse microbial assemblage that may interact with pathogenic fungi, making them potential candidates for disease supression. Olive knot (OK) is a disease caused by the bacterium Pseudomonas savastanoi pv. savastanoi (Psv.) with significant economic losses in olive tree (Olea europaea L.). With this work we want to evaluate the effect of cultivar and OK infection on both endo- and epiphytic fungal community inhabiting olive twig tissues. For this, fungal composition and diversity was assessed in both asymptomatic and OK-symptomatic twigs of tree co-occurring olive cultivars with different susceptibilities to OK disease. The identification of isolated species was performed by ITS rDNA sequencing.
The cultivar and OK infection were important in shaping both endophytic and epiphytic fungal communities. Fungal community composition was found to differ significantly (p=0.005) between olive tree cultivars, being Nectriaceae the dominant family in cvs. Cobrançosa and Verdeal Transmontana, whereas Pleosporaceae was dominant in the cv. Madural. Epiphytic and endophytic fungal communities also differed in size and in composition in asymptomatic and OK-symptomatic twigs, for the three cultivars. In general, asymptomatic twigs were more diverse and rich (up to 1.4-fold) when compared to OK-symptomatic twigs. Among the species identified in the asymptomatic tissues, Cladosporium cladosporioides and Chromelosporium carneum were the most frequently isolated within epiphytic and endophytic community, respectively; whereas in the OK-symptomatic tissues Cladosporium sp. and Fusarium lateritium were the most frequently isolated within epiphytic and endophytic community, respectively. According to indicator species analysis C. carneum, Pyronema dosmesticum and Phoma aloes (IndVal up to 0.56) may be promising species in the OK suppression. Better acknowledgement should be developed in order to uncover their role on plant health.FEDER funds through COMPETE (Programa Operacional Factores de Competitividade}
and by national funds by FCT [Fundação para a Ciência e a Tecnologia) in the framework
of the project EXCL/AGR-PRO/0591/2012. T. Gomes thanks FCT, POPH-QREN and FSE
for PhD SFRH/BD/98127/2013 Grantinfo:eu-repo/semantics/publishedVersio
Ability of fungi isolated from olive tree cultivars with different susceptibilities to olive knot to inhibit Pseudomonas savastanoi pv. savastanoi
The Olive Knot is distributed in olive-growing regions worldwide. This disease is caused by the Pseudomonas savastanoi pv. sovastonoà (Psv), a bacterium that produces galls especially on stems and twigs of olive tree. The use of biological control agents (BCAs)to control plant diseases have gained increasing attention during the last decades, due the negative impact of pesticides on environment and human health. This strategy can offer an alternative in order to achieve a sustainable and environ mentally friendly agriculture. The knowledge of fungal communities inhabiting the phyllosphere of olive tree and the type of interaction that they established with the host plant is essential to explore the use of these microorganisms as BCAs against Olive Knot. Previously, we have characterized the fungal communities inhabiting either the surface (epiphytes) or internal tissues of twigs (endophytes)from olive tree cultivars with different susceptibilities to Olive Knot (Cobrançosa moderately tolerant; Verdeal Transmontana susceptible). In this work, 43 endo- and epiphytes of this fungal community were screened for the suppression of Psv, and several mechanisms behind this activity were also studied by evaluating lytic enzymes production. The interspecific interaction was assessed on two different culture media, potato dextrose agar (PDA)and olive leaf twigs extract (OlTE), with agar overlays and by measuring the zone of growth inhibition. Lytic enzymes were evaluated qualitatively. In general, 95% of the fungal species tested inhibited significantly Psv and above an inhibition index (11) threshold of 1.5, being Dothiorella iberica, Rhinocladiella similis, Phoma aloes and Quambalaria cyanescens the species thatexhibited the maximum values (11 ranging from 31 to 19).The inhibition was observed to be affected by growth medium and correlated with the cultivar from which fungi were isolated. In OlTE was observed higher growth inhibition (up to 1.7 fold) and number of species with 11> 5 (up to 1.9 fold), compared to medium without host plant extracts. Similarly, fungal species isolated from the tolerant cultivar Cobrançosa showed higher capacity to inhibit Psv (up to 1.3 fold) when compared to isolates from cv.Verdeal Transmontana. This effect was noticed either for endophytes or epiphytes. The production of lipase, protease, amylase, and cellulase by fungi contributed to the antagonistic activity against Psv, whose production was influenced by olive tree extracts. Overall, results revealed that intimate physical interaction between fungal endophyte/epiphyte with Psvin the presence of olive tree extracts leads to the production of fungal secondary metabolite compounds that inhibit the pathogen growth, which were otherwise not produced. The potential of these fungal species as biological control agents should be considered and further evaluated under "in vivo" conditions.This work is funded by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia) in the framework of the project EXCL/AGR-PRO/0591/2012.This work is funded by FEDERfunds through COMPETE(Programa Operacional Factores de
Competitividade) and by national funds by FCT(Fundação para a Ciência ea Tecnologia) inthe framework
of the project EXCL/AGR-PRO!0591/2012.T. Gomes thanks FCT, POPH-QRENand FSE for PhD
SFRH/BD/98127/2013 Grant.info:eu-repo/semantics/publishedVersio
Bacterial disease induced changes in fungal communities of olive tree twigs depend on host genotype
In nature, pathogens live and interact with other microorganisms on plant tissues. Yet, the research area exploring interactions between bacteria-fungi and microbiota-plants, within the context of a pathobiome, is still scarce. In this study, the impact of olive knot (OK) disease caused by the bacteria Pseudomonas savastanoi pv. savastanoi (Psv) on the epiphytic and endophytic fungal communities of olive tree twigs from three different cultivars, was investigated in field conditions. The ITS-DNA sequencing of cultivable fungi, showed that OK disease disturbs the resident fungal communities, which may reflect changes in the habitat caused by Psv. In particular, a reduction on epiphyte abundance and diversity, and changes on their composition were observed. Compared to epiphytes, endophytes were less sensitive to OK, but their abundance, in particular of potential pathogens, was increased in plants with OK disease. Host genotype, at cultivar level, contributed to plant fungal assembly particularly upon disease establishment. Therefore, besides fungi - Psv interactions, the combination of cultivar - Psv also appeared to be critical for the composition of fungal communities in olive knots. Specific fungal OTUs were associated to the presence and absence of disease, and their role in the promotion or suppression of OK disease should be studied in the future.This research was partially supported by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds through FCT (Fundacao para a Ciencia e a Tecnologia) in the framework of the project EXCL/AGR-PRO/0591/2012. This work was supported by FCT under the project UID/MULTI/04046/2013. T. Gomes thanks FCT, POPH-QREN and FSE for PhD SFRH/BD/98127/2013 grant; and also the COST Action FA1405 for a short-term scientific mission (STSM) grant
Volumetric and chromatic reintegration in conservation of in situ glazed tiles
Volumetric and chromatic reintegration is one of the most important but challenging
treatments in conservation of in situ glazed tiles due to the need to protect them from water intrusion and further deterioration despise the demanding conditions and requirements needed in outdoor exposure.
A set of six infill pastes based on aerial lime, hydraulic lime, aerial lime plus vinylic resin, epoxy resin and polyester resin binders was selected based on materials applied in previously reported interventions and the experience of professionals working in the field.
The laboratory studies included the characterization of the infill pastes with and without chromatic reintegration/coating layer (SEM, MIP, porosity, water absorption, water vapour permeability, adhesion to the ceramic) and their behaviour after cure, artificial ageing (salt ageing, UV-Temp-RH cycles) and natural ageing. The results obtained allowed to formulate some considerations about these materials, their different characteristics and their
performance when applied in the infill of architectural tile lacunae. The laboratory results have been compared with the performance of similar treatments surveyed on sites where they had been applied
Improving In-Plant Logistics Flow by Physical and Digital Pathways
The automotive industry is constantly using continuous improvement to leverage its growth and sustainability. The improvement of the intralogistics of component companies for the automotive industry is based on the same principles. The Milk-Run System (MRS) allows the inbound transportation of the raw materials containers to the production lines, as well as the return of finished product containers. Thus, it is important to improve the performance of existing vehicle routing system, according to customer demand orders and the assignment of the production line. The present study identified and examined the existing constraints and proposes the improvements to increase the performance of the existing inbound milk-run system. The system capacity and the routing have been redefined as well as the information need to an efficient management system. Since the production is not standardized, the software was developed to assist the management of the milk-run system. Its implementation showed that with one vehicle and four wagons all the production lines are properly assisted. The contributions of this study were the reduction in 15% of the milk-run lap time, the decrease of the number of milk-run laps, allowing the increase of the number of lines assisted by this intralogistics system, permitting the assignment of new tasks to the MRS operator during the idle time. Moreover, unnecessary laps, unwanted stops and exchange of packaging were eliminated.info:eu-repo/semantics/publishedVersio
Metástases Tardias de Melanoma Maligno Cutâneo Primário Fino
Cutaneous malignant melanoma is the third most common type of skin cancer, and its incidence has been rising. Its mortality rate is considerable, due to an aggressive phenotype and great ability of dissemination, mainly in the first years of follow- -up. Late recurrences, those presenting more than 10 years after diagnosis, are rare. The main prognostic factor of cutaneous malignant melanoma is tumor thickness, which also guides management. Thin tumors often have a good prognosis. We report a case of a 66-year-old woman with a history of excision of a thin primary cutaneous malignant melanoma of the dorsum, presenting 16 years later with an unexpected, rapidly progressing and lethal recurrence.O melanoma maligno cutâneo é o terceiro tipo mais comum de cancro de pele, e a sua incidência tem aumentado. A taxa de mortalidade associada é considerável, devido ao seu fenótipo agressivo e grande capacidade de metastização, principalmente nos primeiros anos de seguimento. As recidivas tardias, mais de 10 anos após o diagnóstico, são raras. O principal fator de prognóstico do melanoma maligno cutâneo é a espessura tumoral, que também determina o tipo de abordagem. Os tumores finos, geralmente, têm bom prognóstico. Reportamos o caso de uma mulher de 66 anos com antecedentes de excisão de um melanoma maligno cutâneo primário fino, localizado no dorso, que se apresentou 16 anos mais tarde com uma inesperada recidiva, rapidamente progressiva e letal
Dehydropeptide supramolecular hydrogels and nanostructures as potential peptidomimetic biomedical materials
Supramolecular peptide hydrogels are gaining increased attention, owing to their potential in a variety of biomedical applications. Their physical properties are similar to those of the extracellular matrix (ECM), which is key to their applications in the cell culture of specialized cells, tissue engineering, skin regeneration, and wound healing. The structure of these hydrogels usually consists of a di- or tripeptide capped on the N-terminus with a hydrophobic aromatic group, such as Fmoc or naphthalene. Although these peptide conjugates can offer advantages over other types of gelators such as cross-linked polymers, they usually possess the limitation of being particularly sensitive to proteolysis by endogenous proteases. One of the strategies reported that can overcome this barrier is to use a peptidomimetic strategy, in which natural amino acids are switched for non-proteinogenic analogues, such as D-amino acids, β-amino acids, or dehydroamino acids. Such peptides usually possess much greater resistance to enzymatic hydrolysis. Peptides containing dehydroamino acids, i.e., dehydropeptides, are particularly interesting, as the presence of the double bond also introduces a conformational restraint to the peptide backbone, resulting in (often predictable) changes to the secondary structure of the peptide. This review focuses on peptide hydrogels and related nanostructures, where α,β-didehydro-α-amino acids have been successfully incorporated into the structure of peptide hydrogelators, and the resulting properties are discussed in terms of their potential biomedical applications. Where appropriate, their properties are compared with those of the corresponding peptide hydrogelator composed of canonical amino acids. In a wider context, we consider the presence of dehydroamino acids in natural compounds and medicinally important compounds as well as their limitations, and we consider some of the synthetic strategies for obtaining dehydropeptides. Finally, we consider the future direction for this research area.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CQUM (UID/QUI/00686/2019). FCT, FEDER, PORTUGAL2020 and COMPETE2020 are also acknowledged for funding under research project PTDC/QUI-QOR/29015/2017 (POCI-01-0145-FEDER-029015)
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