1,996 research outputs found

    The rock carvings of Bouça da Cova da Moura (Ardegães, Maia, Northern Portugal) in the context of Late Prehistory in the Leça basin

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    Este texto pretende dar a conhecer o conjunto de gravuras rupestres da Bouça da Cova da Moura. A análise efetuada ao conjunto de signos permitiu denotar, a presença de composições gráficas pertencentes à tradição artística que se convencionou denominar de arte atlântica, representações de cariz mais esquemático e motivos de época histórica. Na envolvência dos afloramentos gravados descobriram-se monumentos megalíticos, áreas de dispersão de materiais cerâmicos datáveis do Calcolítico, uma ocupação da Idade do Bronze, além de materiais dispersos deste período genérico, relevantes para a análise da biografia deste lugar numa pequena escala de análise. A inserção deste locus numa escala mais ampla de análise, ou seja, os Montes do Leandro, pequeno contraforte da serra do Bougado, permite admitir que este complexo de gravuras rupestres faria parte de um vasto território de ampla significação simbólica durante a Pré-história Recente. Neste sentido as diferentes materialidades seriam, resultado de um processo aditivo que resulta da frequência do planalto, da sua da reutilização e reinterpretação, num templo cíclico.The aim of this paper is to offer an overview of the rock art assemblage at Bouça da Cova da Moura in its local and regional contexts. The site is located in Ardegães, parish of Águas Santas, municipality of Maia, district of Porto, in north-western Portugal. Fieldwork carried out in the end of the 20th century and the beginning of the 21st century, resulted in the discovery of new carved surfaces in the place where the well-known ‘pedra partida de Ardegães’ had been found; it was not only possible to unveil aspects related to its topographical context but also to discover other materialities which are spatially related to the rock carvings. Stylistic analysis undertaken to the set of carvings allow us to consider that we are beyond an assemblage which is partly constituted of rock art compositions belonging to the prehistoric art tradition conventionally called atlantic art, there is one schematic human figure and other motifs that belong to historical periods. In the vicinities of the carved outcrops there are megalithic monuments dated to the Neolithic, scatters of pottery fragments probably dated to the Copper Age, evidence for a Bronze Age occupation site, as well as clusters of surface finds from the same period. Overall, the field data recovered so far is extremely relevant for the analysis of the biography of this place at a small scale of analysis. The integration of this locus in a wider spatial scale, i.e. in the plateau that cuts across the territory in the north-south direction linking it to the Bougado hills, allow us to admit that this rock art complex would be part of a vast territory of symbolic significance in Late Prehistory. Thus, the distinct archaeological remains may be the materialisation of the importance of this geomorphological unit in the cognitive map and ideological universe of the prehistoric communities who dwelled, over a long period of time, along the middle basin of the River Neiva. These different materialities would result from a process of addition in the occupation of the plateau, of its reuse and reinterpretation in a cyclical time.Este texto insere-se no projeto Bronze Age Landscapes in the west of Iberian Peninsula / Paisagens da Idade do Bronze no ocidente peninsular (SFRH/BSAB/ 986/10) apoiado e financiado pela FCT no âmbito de uma Bolsa de Licença Sabática.info:eu-repo/semantics/publishedVersio

    MicroRNA signature refine response prediction in CML

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    microRNAs (miRs) dysregulation have emerged as a crucial step in tumorigenesis, being related with cancer development, progression and response to treatment. In chronic myeloid leukaemia (CML), the resistance to tyrosine kinase inhibitors (TKI) is responsible for treatment failure and could be linked to changes in miRs expression. This work aimed to correlate the expression levels of 3 miRs, miR-21, miR-26b and miR-451, with response to TKI treatment in CML patients. miR-451 levels at diagnosis were significantly higher in patients with optimal response after 6 and 12 months of therapy. Conversely, patients without optimal response had highest levels of miR-21. miR-21 and miR-451 appear to be good biomarkers of response, able to predict optimal TKI responders (p < 0.05). Using the combined profile of both miRs, we create a predictive model of optimal response after one year of treatment. This study highlights the role of miR-21 and miR-451 expression levels at diagnosis in predicting which patients achieve the optimal response.info:eu-repo/semantics/publishedVersio

    Zigzag graphene nanoribbon edge reconstruction with stone-wales defects

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    In this paper, we study zigzag graphene nanoribbons with edges reconstructed with Stone-Wales defects, by means of an empirical (first-neighbor) tight-binding method, with parameters determined by ab initio calculations of very narrow ribbons. We explore the characteristics of the electronic band structure with a focus on the nature of edge states. Edge reconstruction allows the appearance of a new type of edge states. They are dispersive, with nonzero amplitudes in both sublattices; furthermore, the amplitudes have two components that decrease with different decay lengths with the distance from the edge; at the Dirac points one of these lengths diverges, whereas the other remains finite, of the order of the lattice parameter. We trace this curious effect to the doubling of the unit cell along the edge, brought about by the edge reconstruction. In the presence of a magnetic field, the zero-energy Landau level is no longer degenerate with edge states as in the case of the pristine zigzag ribbon.Fundacao para a Ciência e a Tecnologia (FCT) SFRH/BD/44456/2008.FEDER - Programa Operacional Factores de Competitividade - COMPET

    Preserving Both Privacy and Utility in Network Trace Anonymization

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    As network security monitoring grows more sophisticated, there is an increasing need for outsourcing such tasks to third-party analysts. However, organizations are usually reluctant to share their network traces due to privacy concerns over sensitive information, e.g., network and system configuration, which may potentially be exploited for attacks. In cases where data owners are convinced to share their network traces, the data are typically subjected to certain anonymization techniques, e.g., CryptoPAn, which replaces real IP addresses with prefix-preserving pseudonyms. However, most such techniques either are vulnerable to adversaries with prior knowledge about some network flows in the traces, or require heavy data sanitization or perturbation, both of which may result in a significant loss of data utility. In this paper, we aim to preserve both privacy and utility through shifting the trade-off from between privacy and utility to between privacy and computational cost. The key idea is for the analysts to generate and analyze multiple anonymized views of the original network traces; those views are designed to be sufficiently indistinguishable even to adversaries armed with prior knowledge, which preserves the privacy, whereas one of the views will yield true analysis results privately retrieved by the data owner, which preserves the utility. We present the general approach and instantiate it based on CryptoPAn. We formally analyze the privacy of our solution and experimentally evaluate it using real network traces provided by a major ISP. The results show that our approach can significantly reduce the level of information leakage (e.g., less than 1\% of the information leaked by CryptoPAn) with comparable utility

    Genetic variants of ABC and SLC transporter genes and chronic myeloid leukaemia: impact on susceptibility and prognosis

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    Solute carrier (SLC) and ATP-binding cassette (ABC) transporters comprise a variety of proteins expressed on cell membranes responsible for intrusion or extrusion of substrates, respectively, including nutrients, xenobiotics, and chemotherapeutic agents. These transporters mediate the cellular disposition of tyrosine kinase inhibitors (TKIs), and their genetic variants could affect its function, potentially predisposing patients to chronic myeloid leukaemia (CML) and modulating treatment response. We explored the impact of genetic variability (single nucleotide variants—SNVs) of drug transporter genes (ABCB1, ABCG2, SLC22A1, and SLC22A5) on CML susceptibility, drug response, and BCR-ABL1 mutation status. We genotyped 10 SNVs by tetra-primers-AMRS-PCR in 198 CML patients and 404 controls, and assessed their role in CML susceptibility and prognosis. We identified five SNVs associated with CML predisposition, with some variants increasing disease risk, including TT genotype ABCB1 (rs1045642), and others showing a protective effect (GG genotype SLC22A5 rs274558). We also observed different haplotypes and genotypic profiles associated with CML predisposition. Relating to drug response impact, we found that CML patients with the CC genotype (rs2231142 ABCG2) had an increased risk of TKI resistance (six-fold). Additionally, CML patients carrying the CG genotype (rs683369 SLC22A1) presented a 4.54-fold higher risk of BCR-ABL1 mutations. Our results suggest that drug transporters’ SNVs might be involved in CML susceptibility and TKI response, and predict the risk of BCR-ABL1 mutations, highlighting the impact that SNVs could have in therapeutic selection.info:eu-repo/semantics/publishedVersio

    New nanotechnologies for the treatment and repair of skin burns infections

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    Burn wounds are highly debilitating injuries, with significant morbidity and mortality rates worldwide. In association with the damage of the skin integrity, the risk of infection is increased, posing an obstacle to healing and potentially leading to sepsis. Another limitation against healing is associated with antibiotic resistance mainly due to the use of systemic antibiotics for the treatment of localized infections. Nanotechnology has been successful in finding strategies to incorporate antibiotics in nanoparticles for the treatment of local wounds, thereby avoiding the systemic exposure to the drug. This review focuses on the most recent advances on the use of nanoparticles in wound dressing formulations and in tissue engineering for the treatment of burn wound infections.The authors would like to thank the financial support received from Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project references M-ERA-NET/0004/2015-PAIRED and UIDB/04469/2020, co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio
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