Wildfire patterns and landscape changes in Mediterranean oak woodlands

Fire is infrequent in the oak woodlands of southern Portugal (montado) but large and severe fires affected these agro-forestry systems in 2003–2005. We hypothesised transition from forest to shrubland as a fire-driven process and investigated the links between fire incidence and montado change to other land cover types, particularly those related with the presence of pioneer communities (generically designed in this context as “transitions to early-successional communities”). We present a landscape-scale framework for assessing the probability of transition from montado to pioneer communities, considering three sets of explanatory variables: montado patterns in 1990 and prior changes from montado to early-successional communities (occurred between 1960 and 1990), fire patterns, and spatial factors. These three sets of factors captured 78.2% of the observed variability in the transitions from montado to pioneer vegetation. The contributions of fire patterns and spatial factors were high, respectively 60.6% and 43.4%, the influence of montado patterns and former changes in montado being lower (34.4%). The highest amount of explained variation in the occurrence of transitions from montado to earlysuccessional communities was related to the pure effect of fire patterns (19.9%). Low spatial connectedness in montado landscape can increase vulnerability to changes, namely to pioneer vegetation, but the observed changes were mostly explained by fire characteristics and spatial factors. Among all metrics used to characterize fire patterns and extent, effective mesh size provided the best modelling results. Transitions from montado to pioneer communities are more likely in the presence of high values of the effective mesh size of total burned area. This cross-boundary metric is an indicator of the influence of large fires in the distribution of the identified transitions and, therefore, we conclude that the occurrence of large fires inmontado increases its probability of transition to shrubland

CAMILA: formal software engineering supported by functional programming

This paper describes two experiences in teaching a formal approach to software engineering at undergraduate level supported by Camila a functional programming based tool Carried on in diferent institutions each of them addresses a particular topic in the area requirement analysis and generic systems design in the first case specification and implementation development in the second Camila the common framework to both experiences animates a set based language extended with a mild use of category theory which can be reasoned upon for program calculation and classification purpose. The project afiliates itself to but is not restricted to the research in exploring Functional Programming as a rapid prototyping environment for formal software model. Its kernel is fully connectable to external applications and equipped with a component repository and distribution facilities. The paper explains how Camila is being used in the educational practice as a tool to think with providing a kind of cross fertilization between students under standing of diferent parts of the curriculum. Furthermore it helps in developinga number of engineering skills namely the ability to analyze and classify information problems and models and to resort to the combined use of diferent programming frameworks in approaching them

Development and characterization of a novel hybrid tissue engineering-based scaffold for spinal cord injury repair

Spinal cord injury (SCI) represents a significant health and social problem, and therefore it is vital to develop novel strategies that can specifically target it. In this context, the objective of the present work was to develop a new range of three-dimensional (3D) tubular structures aimed at inducing the regeneration within SCI sites. Up to six different 3D tubular structures were initially developed by rapid prototyping: 3D bioplotting–based on a biodegradable blend of starch. These structures were then further complemented by injecting Gellan Gum, a polysaccharide-based hydrogel, in the central area of structures. The mechanical properties of these structures were assessed using dynamic mechanical analysis, under both dry and wet conditions, and their morphologies= porosities were analyzed using micro-computed tomography and scanning electron microscopy. Biological evaluation was carried out to determine their cytotoxicity, using both minimum essential medium (MEM) extraction and MTS tests, as well as by encapsulation of an oligodendrocyte-like cell (M03-13 cell line) within the hydrogel phase. The histomorphometric analysis showed a fully interconnected network of pores with porosity ranging from 70% to 85%. Scaffolds presented compressive modulus ranging from 17.4 to 62.0MPa and 4.42 to 27.4 MPa under dry and wet conditions, respectively. Cytotoxicity assays revealed that the hybrid starch=poly-ecaprolactone= Gellan Gum scaffolds were noncytotoxic, as they did not cause major alterations on cell morphology, proliferation, and metabolic viability. Moreover, preliminary cell encapsulation assays showed that the hybrid scaffolds could support the in vitro culture of oligodendrocyte-like cells. Finally, preliminary in vivo studies conducted in a hemisection rat SCI model revealed that the above-referred structures were well integrated within the injury and did not trigger chronic inflammatory processes. The results herein presented indicate that these 3D systems might be of use in future SCI regeneration approaches.Portuguese Foundation for Science and Technology through funds from Programa Operacional Ciencia, Tecnologia, Inovacao (POCTI) and/or Fundo Europeu de Desenvolvimento Regional (FEDER) programs (funding to ICVS, 3B's Research Group, predoctoral and postdoctoral fellowships to N. A. Silva, J. T. Oliveira, A. J. Salgado, and R. A. Sousa-SFRH/BD/40684/2007; SFRH/BD/17135/2004; SFRH/BPD/17595/2004; SFRH/BPD/17151/2004)

Finite element analysis of pectus carinatum surgical correction via a minimally invasive approach

Pectus carinatum (PC) is a chest deformity caused by a disproportionate growth of the costal cartilages compared to the bony thoracic skeleton, pulling the sternum towards, which leads to its protrusion. There has been a growing interest on using the 'reversed Nuss' technique as a minimally invasive procedure for PC surgical correction. A corrective bar is introduced between the skin and the thoracic cage and positioned on top of the sternum highest protrusion area for continuous pressure. Then, it is fixed to the ribs and kept implanted for about 2-3 years. The purpose of this work was to (a) assess the stresses distribution on the thoracic cage that arise from the procedure, and (b) investigate the impact of different positioning of the corrective bar along the sternum. The higher stresses were generated on the 4th, 5th and 6th ribs backend, supporting the hypothesis of pectus deformities correction-induced scoliosis. The different bar positioning originated different stresses on the ribs' backend. The bar position that led to lower stresses generated on the ribs backend was the one that also led to the smallest sternum displacement. However, this may be preferred, as the risk of induced scoliosis is lowered.This work was financially supported by the Potuguese Foundation for Science and Techrnology (FCT) under the R&D project PTDC/SAU-BEB/103368/2008 and the fellowship SFRH/BPD/46851/2008

Influence of PDLA nanoparticles size on drug release and interaction with cells

Polymeric nanoparticles (NPs) are strong candidates for the development of systemic and targeted drug delivery applications. Their size is a determinant property since it defines the NP–cell interactions, drug loading capacity, and release kinetics. Herein, poly(D,L-lactic acid) (PDLA) NPs were produced by the nanoprecipitationmethod, in which the influence of type and concentration of surfactant as well as PDLA concentration were assessed. The adjustment of these parameters allowed the successful production of NPs with defined medium sizes, ranging from 80 to 460 nm. The surface charge of the different NPs populations was consistently negative. Prednisolone was effectively entrapped and released from NPs with statistically different medium sizes (i.e., 80 or 120 nm). Release profiles indicate that these systems were able to deliver appropriate amounts of drug with potential applicability in the treatment of inflammatory conditions. Both NPs populations were cytocompatible with human endothelial and fibroblastic cells, in the range of concentrations tested (0.187–0.784 mg/mL). However, confocal microscopy revealed that within the range of sizes tested in our experiments, NPs presenting amedium size of 120 nmwere able to be internalized in endothelial cells. In summary, this study demonstrates the optimization of the processing conditions to obtain PDLA NPs with narrow size ranges, and with promising performance for the treatment of inflammatory diseases.info:eu-repo/semantics/publishedVersio

Starch/gellan gum hybrid 3D guidance systems for spinal cord injury regeneration: Scaffolds processing, characterization and biological evaluation

[Excerpt] Spinal cord injury (SCI) represents a significant health and social problem and therefore it is urgent to find strategies that can specifically target this problem. In this sense the objective of the present work was to develop a new range of 3D tubular structures aimed at inducing the regeneration within SCI sites. Up to six different 3D tubular structures were initially developed by rapid prototyping-3D bioplotting–based on a biodegradable blend of starch. The mechanical properties of these structures were assessed by DMA, in both dry and wet conditions, and their morphologies/ porosities analysed by micro-CT and SEM. Afterwards, gellan gum hydrogel was injected in the central area of structures. [...]info:eu-repo/semantics/publishedVersio

Automating the processing steps for obtaining bone tissue engineered substitutes : from imaging tools to bioreactors.

Bone diseases and injuries are highly incapacitating and result in a high demand for tissue substitutes with specific biomechanical and structural features. Tissue engineering has already proven to be effective in regenerating bone tissue but has not yet been able to become an economically viable solution due to the complexity of the tissue which is very difficult to be replicated, eventually requiring the utilization of highly labour-intensive processes. Process automation is seen as the solution for mass production of cellularized bone tissue substitutes at an affordable cost by being able to reduce human intervention as well as reducing product variability. The combination of tools such as medical imaging, computer-aided fabrication and bioreactor technologies, which are currently used in tissue engineering, shows potential to generate automated production ecosystems which will in turn enable the generation of commercially available products with widespread clinical application.The authors would like to acknowledge the partial support by the European Network of Excellence EXPERTISSUES (NMP3-CT-2004-500283). Pedro Costa would also like to acknowledge the Portuguese Foundation for Science and Technology for his PhD grant (SFRH/BD/62452/2009)

In vitro characterization on the interactions between carboxymethyl-chitosan/poly(amidoamine) dendrimer nanoparticles and neurons/glial cells

[Excerpt] Central nervous system associated disorders are a leading cause of disability worldwide. In recent years targeted drug delivery nanoparticle based systems for intracellular application have been put forward has a possible therapeutic route to follow. In this sense the objective of the present report was to characterize and evaluate the possible applicability of recently developed carboxymethylchitosan/poly(amidoamine) (CMC/PAMAM) dendrimer nanoparticles in central nervous system (CNS) cell populations. Atomic force and transmission electron microscopy observations revealed that these nanoparticles possessed a nanosphere-like shape and sizes between 2–123 nm. [...]info:eu-repo/semantics/publishedVersio

JITeR: Just-in-time application-layer routing

The paper addresses the problem of providing message latency and reliability assurances for control traf- fic in wide-area IP networks. This is an important problem for cloud services and other geo-distributed information infrastructures that entail inter-datacenter real-time communication. We present the design and validation of JITeR ( Just-In-Time Routing ), an algorithm that timely routes messages at application- layer using overlay networking and multihoming, leveraging the natural redundancy of wide-area IP net- works. We implemented a prototype of JITeR that we evaluated experimentally by placing nodes in sev- eral regions of Amazon EC2. We also present a scenario-based (geo-distributed utility network) evalua- tion comparing JITeR with alternative overlay/multihoming routing algorithms that shows that it provides better timeliness and reliability guarantees

An insight into the synthesis of cationic porphyrin-imidazole derivatives and their photodynamic inactivation efficiency against Escherichia coli

New porphyrin-imidazole derivatives were synthesised by Radziszewski reaction between 2-formyl-5,10,15,20-tetraphenylporphyrin 1 and several (hetem)aromatic 1,2-diones, which after cationization afforded promising monocationic photosensitizers 3a-d. Singlet oxygen studies have demonstrated that all the cationic porphyrin-imidazole conjugates 3a-d were capable to produce cytotoxic species. These photosensitizers were able to photoinactivate Eschericha coli and their inactivation profile was improved in the presence of KI.The authors are grateful to University of Aveiro and FCT/MCT for the financial support for QOPNA research Unit (FCT UID/QUI/00062/2019), the LAQV-REQUIMTE (UIDB/50006/2020), CESAM (UID/AMB/50017/2019) and CQUM (QUI/UI0686/2018) through national founds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement, and to the Portuguese NMR Network. The research contract of N.M.M. Moura (REF.-048-88-ARH/2018) is funded by national funds (OE), through FCT - Fundacao para a Ciencia e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19