Browsing by Issue Date, starting with "2016-09"
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- Topologia, anamorfose, e o bestiário das perspectivas curvilíneasPublication . Araújo, António BandeiraFaz-se uma breve digressão pelo catálogo das perspectivas curvilíneas centrais, descrevendo algumas das suas propriedades topológicas, geométricas, e ópticas, enfatizando a sua ligação com o conceito fundamental de anamorfose com vista a esclarecer alguns equívocos clássicos relativos à posição fundamental ocupada pela perspectiva clássica.
- An introduction to helpful forecasting methods for hotel revenue managementPublication . Pereira, LuisRevenue management is a key tool for hotel managers' decision-making process. Cutting-edge revenue management systems have been developed to support managers' decisions and all have as an essential component an accurate forecasting module. This paper aims to introduce new time series forecasting models to be considered as a tool for forecasting daily hotel occupancies. These models were developed in a state space modelling framework which is capable of tackling seasonal complexities such as multiple seasonal periods and non-integer seasonality. An empirical study was carried out to illustrate how a practitioner may apply and compare the performance of different models when forecasting a hotel's daily occupancy. Results showed that the trigonometric model based on the new modelling framework generally outperformed the majority of the other models. These findings are potentially useful to the entire revenue management community facing the challenge of accurately forecasting a hotel's daily demand. (C) 2016 Elsevier Ltd. All rights reserved.
- Mortality predictive factors in subjects with COPD after a pulmonary rehabilitation program: A 3-year studyPublication . Saraiva, Catia; Abreu, Tiago; Neves, Djamila; Rodrigues, FatimaBACKGROUND: COPD is a high-mortality disease and projected to become the third leading cause of death worldwide by 2030. Our aim was to evaluate predictors of 3-y mortality and factors associated with early (1 y) and late (second and third year) mortality in subjects with severe COPD who completed a pulmonary rehabilitation program. METHODS: A historical cohort study was performed with subjects with COPD who were admitted to a day-hospital for chronic respiratory failure for a pulmonary rehabilitation program, from January 2008 to December 2010. The population was characterized based on sociodemographic factors, body mass index, smoking habits, lung function tests, respiratory failure, comorbidities, bacterial colonization, Modified Medical Research Council dyspnea index, 6-min walk test, mechanical ventilation, noninvasive ventilation, long-term oxygen therapy, hospital admissions, and mortality. RESULTS: From 183 patients who completed a pulmonary rehabilitation program, 93 had COPD. Our cohort had 78 male and 15 female subjects. The mean age +/- SD was 68.6 +/- 8.9 y, ranging from 43 to 85 y. After the pulmonary rehabilitation program, there were fewer, although not statistically significantly different hospital admissions (2.1 vs 1.7, P =.17). Three years after the pulmonary rehabilitation program, 34 subjects died (36.6%). Hypercapnic respiratory failure (P = .02), noninvasive ventilation (P = .002), lung cancer (P = .001), shorter 6-min walk distance (P = .03), and higher number of previous hospital admissions (P <.001) were associated with a higher mortality rate. CONCLUSION: There is a high mortality rate in late-stage patients with COPD. The most relevant factors associated with mortality were lung cancer, respiratory failure and noninvasive ventilation, severe exacerbations with hospitalization, and lower functional exercise capacity.
- Building the landscape. Rehabilitation and renewal of traditional mediterranean structuresPublication . Bragança, Carlos; Marçal Gonçalves, MartaOne of the main features of Mediterranean landscapes, particularly in limestone areas, is the terraced land frame, usually supported by dry stone walls. In addition to the scenic aspects and landscape identity, network compartmentalization established by terraces, property division walls, pathways and traditional paths, shapes ecological corridors that frame the different human activities. It is a structure whose conservation is particularly important in areas of intense human impact, or rapid transformation, such as the urban-tourist spaces of the Algarve, where the hills displayed by such structures form the background scenario. In order to put in value their importance for landscape conservation and evolution, this presentation will focus on the interrelated ecological, aesthetic, symbolic, socioeconomic and political aspects that influence the spatial distribution and image of the terraces. Of course, the values that local people can assign to their landscapes will be determinant, but specially at the Algarve, the role of tourists as outsiders must be seriously take into account. We then argue that the future of the dry stone walls structure must be prospected into the diversity of possible solutions about landscape development as the living part of a whole unit that includes the densest urbanized areas with less ecological functions. We call such unit the urban-touristic region of Algarve, inspired on two utopic references: the ‘urban regions’ and the ‘Agroplia’. It means that we try to use landscape as an instrument of knowledge and acknowledgement –democratic governance– of regional spaces.
- The microbiome of coral surface mucus has a key role in mediating holobiont health and survival upon disturbancePublication . Glasl, Bettina; Herndl, Gerhard J.; Frade, Pedro R.Microbes are well-recognized members of the coral holobiont. However, little is known about the short-term dynamics of mucus-associated microbial communities under natural conditions and after disturbances, and how these dynamics relate to the host's health. Here we examined the natural variability of prokaryotic communities (based on 16S ribosomal RNA gene amplicon sequencing) associating with the surface mucus layer (SML) of Porites astreoides, a species exhibiting cyclical mucus aging and shedding. Shifts in the prokaryotic community composition during mucus aging led to the prevalence of opportunistic and potentially pathogenic bacteria (Verrucomicrobiaceae and Vibrionaceae) in aged mucus and to a twofold increase in prokaryotic abundance. After the release of aged mucus sheets, the community reverted to its original state, dominated by Endozoicimonaceae and Oxalobacteraceae. Furthermore, we followed the fate of the coral holobiont upon depletion of its natural mucus microbiome through antibiotics treatment. After re-introduction to the reef, healthy-looking microbe-depleted corals started exhibiting clear signs of bleaching and necrosis. Recovery versus mortality of the P. astreoides holobiont was related to the degree of change in abundance distribution of the mucus microbiome. We conclude that the natural prokaryotic community inhabiting the coral SML contributes to coral health and that cyclical mucus shedding has a key role in coral microbiome dynamics.
- Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticusPublication . Cerqueira, Marco; Rey, Sonia; Silva, Tome; Featherstone, Zoe; Crumlish, Margaret; MacKenzie, Simon1. Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction.2. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution.3. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 degrees C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish.4. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days.5. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice.
- Informational constraints on interceptive actions of elite football goalkeepers in 1v1 dyads during competitive performancePublication . Shafizadeh, Mohsen; Davids, Keith; Correia, Vanda; Wheat, Jonathan; Hizan, HazuanThe aim of this study was to examine whether perceptual variables can provide informational constraints for the goalkeepers to intercept the ball successfully in 1v1 dyads. Video images of 42 actions (1v1 in direct shots) were selected randomly from different matches and divided into conceded goals (n=20) and saved actions (n=22) to investigate interceptive actions of 20 goalkeepers in the English Premier League in season 2013-2014. Time to Contact (TTC) of the closing distance gap between shooter and goalkeeper was obtained by digitising actions in the 18-yard penalty box. Statistical analyses revealed that, in sequences of play resulting in an intercepted shot at goal, goalkeepers closed down outfield players in the X axis, whereas when a goal was conceded, there was a significantly delayed movement by goalkeepers toward the shooters in this plane. The results of canonical correlations showed that a decreasing distance between a shooter and goalkeeper, and accompanied reduction in relative interpersonal velocity followed a temporal pattern. Findings of this study showed how perception of key informational constraints on dyadic system relations, such as TTC, interpersonal distance and relative velocity, constrain elite goalkeepers' interceptive actions, playing an important role in successful performance.
- Multitaxon activity profiling reveals differential microbial response to reduced seawater pH and oil pollutionPublication . Coelho, Francisco J. R. C.; Cleary, Daniel F. R.; Costa, Rodrigo; Ferreira, Marina; Polonia, Ana R. M.; Silva, Artur M. S.; Simoes, Mario M. Q.; Oliveira, Vanessa; Gomes, Newton C. M.There is growing concern that predicted changes to global ocean chemistry will interact with anthropogenic pollution to significantly alter marine microbial composition and function. However, knowledge of the compounding effects of climate change stressors and anthropogenic pollution is limited. Here, we used 16S and 18S rRNA (cDNA)-based activity profiling to investigate the differential responses of selected microbial taxa to ocean acidification and oil hydrocarbon contamination under controlled laboratory conditions. Our results revealed that a lower relative abundance of sulphate-reducing bacteria (Desulfosarcina/Desulfococcus clade) due to an adverse effect of seawater acidification and oil hydrocarbon contamination (reduced pH-oil treatment) may be coupled to changes in sediment archaeal communities. In particular, we observed a pronounced compositional shift and marked reduction in the prevalence of otherwise abundant operational taxonomic units (OTUs) belonging to the archaeal Marine Benthic Group B and Marine Hydrothermal Vent Group (MHVG) in the reduced pH-oil treatment. Conversely, the abundance of several putative hydrocarbonoclastic fungal OTUs was higher in the reduced pH-oil treatment. Sediment hydrocarbon profiling, furthermore, revealed higher concentrations of several alkanes in the reduced pH-oil treatment, corroborating the functional implications of the structural changes to microbial community composition. Collectively, our results advance the understanding of the response of a complex microbial community to the interaction between reduced pH and anthropogenic pollution. In future acidified marine environments, oil hydrocarbon contamination may alter the typical mixotrophic and k-/r-strategist composition of surface sediment microbiomes towards a more heterotrophic state with lower doubling rates, thereby impairing the ability of the ecosystem to recover from acute oil contamination events.
- A method for sex estimation using the proximal femurPublication . Curate, Francisco; Coelho, João; Gonçalves, David; Coelho, Catarina; Ferreira, Maria Teresa; Navega, David; Cunha, EugéniaThe assessment of sex is crucial to the establishment of a biological profile of an unidentified skeletal individual. The best methods currently available for the sexual diagnosis of human skeletal remains generally rely on the presence of well-preserved pelvic bones, which is not always the case. Postcranial elements, including the femur, have been used to accurately estimate sex in skeletal remains from forensic and bioarcheological settings. In this study, we present an approach to estimate sex using two measurements (femoral neck width [FNW] and femoral neck axis length [FNAL]) of the proximal femur. FNW and FNAL were obtained in a training sample (114 females and 138 males) from the Luis Lopes Collection (National History Museum of Lisbon). Logistic regression and the C4.5 algorithm were used to develop models to predict sex in unknown individuals. Proposed cross-validated models correctly predicted sex in 82.5-85.7% of the cases. The models were also evaluated in a test sample (96 females and 96 males) from the Coimbra Identified Skeletal Collection (University of Coimbra), resulting in a sex allocation accuracy of 80.1-86.2%. This study supports the relative value of the proximal femur to estimate sex in skeletal remains, especially when other exceedingly dimorphic skeletal elements are not accessible for analysis. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
- Evolution problems of Navier-Stokes type with anisotropic diffusionPublication . Antontsev, S. N.; de Oliveira, H. B.In this work, we consider the evolutive problem for the incompressible Navier-Stokes equations with a general diffusion which can be fully anisotropic. The existence of weak solutions is proved for the associated initial problem supplemented with no-slip boundary conditions. We prove also the properties of extinction in a finite time, exponential time decay and power time decay. With this respect, we consider the important case of a forces fields with possible different behavior in distinct directions. Perturbations of the asymptotically stable equilibrium are established as well.