440 research outputs found
Formal verification of kLIBC with the WP frama-C plug-in
This paper presents our results in the formal verification of kLIBC, a minimalistic C library, using the Frama-C/WP tool. We report how we were able to completely verify a significant number of functions from and . We discuss difficulties encountered and describe in detail a problem in the implementation of common functions, for which we suggest alternative implementations. Our work shows that it is presently already viable to verify low-level C code, with heavy usage of pointers. Although the properties proved tend to be shallower as the code becomes of a lower-level nature, it is our view that this is an important direction towards real-world software verification, which cannot be attained by focusing on deep properties of cleaner code, written specifically to be verified.This work is funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT - Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-020486
Adipose tissue derived stem cells secretome: soluble factors and their roles in regenerative medicine
Stem cells have been long looked at as possible therapeutic vehicles for different health related problems. Among the different
existing stem cell populations, Adipose derived Stem Cells (ASCs) have been gathering attention in the last 10 years. When compared to
other stem cells populations and sources, ASCs can be easily isolated while providing higher yields upon the processing of adipose tissue.
Similar to other stem cell populations, it was initially thought that the main potential of ASCs for regenerative medicine approaches was
intimately related to their differentiation capability. Although this is true, there has been an increasing body of literature describing the
trophic effects of ASCs on the protection, survival and differentiation of a variety of endogenous cells/tissues. Moreover, they have also
shown to possess an immunomodulatory character. This effect is closely related to the ASCs’ secretome and the soluble factors found
within it. Molecules such as hepatocyte growth factor (HGF), granulocyte and macrophage colony stimulating factors, interleukins (ILs)
6, 7, 8 and 11, tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), brain derived neurotrophic factor (BDNF),
nerve growth factor (NGF), adipokines and others have been identified within the ASCs’ secretome. Due to its importance regarding future
applications for the field of regenerative medicine, we aim, in the present review, to make a comprehensive analysis of the literature
relating to the ASCs’ secretome and its relevance to the immune and central nervous system, vascularization and cardiac regeneration.
The concluding section will highlight some of the major challenges that remain before ASCs can be used for future clinical applications
0-dimensional persistent homology analysis implementation in resource-scarce embedded systems
Persistent Homology (PH) analysis is a powerful tool for understanding many relevant topological features from a given dataset. PH allows finding clusters, noise, and relevant connections in the dataset. Therefore, it can provide a better view of the problem and a way of perceiving if a given dataset is equal to another, if a given sample is relevant, and how the samples occupy the feature space. However, PH involves reducing the problem to its simplicial complex space, which is computationally expensive and implementing PH in such Resource-Scarce Embedded Systems (RSES) is an essential add-on for them. However, due to its complexity, implementing PH in such tiny devices is considerably complicated due to the lack of memory and processing power. The following paper shows the implementation of 0-Dimensional Persistent Homology Analysis in a set of well-known RSES, using a technique that reduces the memory footprint and processing power needs of the 0-Dimensional PH algorithm. The results are positive and show that RSES can be equipped with this real-time data analysis tool.This work has been supported by FCT-Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020
Cartografia de uso/ocupação do solo por fotointerpretação: Um exemplo de análise sobre o concelho de Oeiras
O artigo pretende demonstrar como as evoluções tecnológicas e cientÃficas têm contribuÃdo para um melhor conhecimento dos fenómenos que decorrem à superfÃcie terrestre, e consequentemente para um mais correcto ordenamento do território. Nele se expõem alguns dos métodos e técnicas que se foram desenvolvendo e experimentando no decurso dum projecto1 de monitorização da evolução do uso do solo para área metropolitana de Lisboa. O que aqui se relata não são somente os procedimentos técnicos relativos à fotointerpretação de fotografias aéreas verticais, e consequente produção da cartografia de uso do solo, mas também uma proposta metodológica para análise, quer quantitativa, quer qualitativa da dinâmica de uso do solo, para os anos de 1991 e 1995. Para sua concretização recorreu-se à s Tecnologias de Informação Geográfica (TIG), em que a integração de informação geográfica proveniente dos processos de fotointerpretação e análise espacial por aplicação de algoritmos complexos, mediante acesso a avançados programas de Sistemas de Informação Geográfica (SIG), é realizado com relativa facilidade e em tempo útil. A área teste é um extracto do território do concelho de Oeiras, escolhida por duas razões: proximidade fÃsica, que permitiu as várias visitas ao terreno; e o facto de se tratar de uma área periurbana, onde a heterogeneidade de usos do solo é rica e é sabido terem ocorrido um conjunto significativo de transformações para os anos em estudo. O exercÃcio foi desenvolvido no decurso dos trabalhos práticos da cadeira de Cartografia Temática do curso de licenciatura em Geografia, variante de Cartografia e Sistemas de Informação Geográfica da Faculdade de Letras da Universidade de Lisboa.info:eu-repo/semantics/publishedVersio
A rare cecal subepithelial tumor in a Crohn´s Disease patient
Appendiceal tumors comprise a variety of histologic types, including appendiceal mucinous neoplasms, which can be grouped as premalignant lesions, tumors of uncertain malignant potential, and malignant lesions. The appendiceal mucinous neoplasms are characterized by mucinous epithelial proliferation with extracellular mucin and pushing tumor margins, commonly an incidental finding during operative exploration. We report the case of a low-grade appendiceal mucinous neoplasm presenting as a subepithelial lesion in Crohn´s Disease patient. The diagnosis was not straightforward, and only surgical resection allowed an accurate diagnosis. Although Inflammatory Bowel Disease is a risk factor for the development of colorectal neoplasms, the absolute risk for appendiceal tumors is uncertain. The frequency of progression to malignancy remains to be determined
Online data mining services for dynamic spatial databases I: system architecture and client applications
This paper describes online data mining services for dynamic spatial databases connected to environmental monitoring networks. These services can use Artificial Neural Networks as data mining techniques to find temporal relations in monitored parameters. The execution of the data mining algorithms is performed at the server side and a distributed processing scheme is used to overcome problems of scalability.
To support the discovery of temporal relations, two other families of online services are made available: vectorial and raster visualization services and a sonification service. The use of this system is illustrated by the DM Plus client application and the SNIRH Data Mining Web site. The sonification service is described and illustrated in the part II paper
Disease-related malnutrition and its repercussions in Portugal
A malnutrição associada à doença é frequente do ponto de vista clÃnico, apresentando elevada morbilidade, mortalidade e impacto na qualidade de vida, em especialidades como a medicina interna, a oncologia, a neurologia, a gastroenterologia e a pediatria, entre outras. Estudos realizados em Portugal estimam existirem cerca de 40% de doentes em risco nutricional à data da admissão hospitalar, dependendo do estadio da doença e do grau/severidade. O custo da hospitalização destes doentes, é cerca de 20% superior ao dos doentes com o mesmo grupo de diagnóstico homogéneo, mas sem risco nutricional associado. No nosso paÃs, o acesso dos doentes malnutridos a avaliação, aconselhamento e tratamento nutricional adequados ainda é limitado, mesmo em ambiente hospitalar. Um conhecimento detalhado da malnutrição associada à doença nas referidas especialidades, permitiria uma melhor caracterização da situação em Portugal, e permitiria estabelecer uma estratégia de intervenção clÃnica e terapêutica, para melhorar este panorama e as suas consequências no nosso paÃs.ABSTRACT - Disease-related malnutrition is clinically common, with high morbidity, mortality, and quality of life impact in medical specialties like internal medicine, oncology, neurology, gastroenterology, and pediatrics, among others. Studies in Portugal have estimated that about 40% of patients are at nutritional risk at hospital admission, depending on disease condition and stage/severity. The hospitalization costs for treating these patients is in average 20% higher than the respective, not at risk diagnosis-related group. The access to an adequate evaluation, counseling and nutritional treatment for malnourished patients is still limited in our country, even in the hospital setting. Detailed knowledge of disease-related malnutrition in the above mentioned medical specialties would allow to better characterize the situation in Portugal, to establish clinical and therapeutic intervention plans in order to improve the situation and consequences in our country.info:eu-repo/semantics/publishedVersio
Mycobacterium tuberculosis strains are differentially recognized by TLRs with an impact on the immune response
Tuberculosis associates with a wide spectrum of disease outcomes. The Beijing (Bj) lineage of Mycobacterium tuberculosis (Mtb) is suggested to be more virulent than other Mtb lineages and prone to elicit non-protective immune responses. However, highly heterogeneous immune responses were reported upon infection of innate immune cells with Bj strains or stimulation with their glycolipids. Using both in vitro and in vivo mouse models of infection, we here report that the molecular mechanism for this heterogeneity may be related to distinct TLR activations. Among this Mtb lineage, we found strains that preferentially activate TLR2, and others that also activate TLR4. Recognition of Mtb strains by TLR4 resulted in a distinct cytokine profile in vitro and in vivo, with specific production of type I IFN. We also uncover a novel protective role for TLR4 activation in vivo. Thus, our findings contribute to the knowledge of the molecular basis underlying how host innate immune cells handle different Mtb strains, in particular the intricate host-pathogen interaction with strains of the Mtb Bj lineage.This work has been funded by Fundacao para a Ciencia e Tecnologia, Portugal. Project grants: PTDC/SAU-MII/101977/2008 and PTDC/BIA-BCM/102776/2008. Personal grants: SFRH/BD/35981/2007 to JC; SFRH/BPD/3306/2007 to AC; SFRH/BPD/77399/2011 to LMT; SFRH/BI/33456/2008 to CS; and SFRH/BPD/33959/2009 to NSO. MS is a Ciencia 2007 fellow. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Performance of the ATLAS Track Reconstruction Algorithms in Dense Environments in LHC Run 2
With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb of data collected by the ATLAS experiment and simulation of proton–proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 . The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The track reconstruction efficiency in the cores of jets with transverse momenta between 200 and 1600 is quantified using a novel, data-driven, method. The method uses the energy loss, , to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is and for jet transverse momenta of 200–400 and 1400–1600 , respectively.Peer Reviewe
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