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
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
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
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
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
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
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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