Browsing by Issue Date, starting with "2019-06"
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- A responsabilidade social na estratégia das empresas: o caso das startups sociaisPublication . Júnior, Patrícia Juliana Miguel; Martins, José MoleiroA presente dissertação, elaborada no âmbito do Mestrado em Gestão e Empreendedorismo, do Instituto Superior de Contabilidade e Administração de Lisboa, aborda a influência da responsabilidade social na estratégia das startups sociais. Partindo-se da evolução da responsabilidade social para a responsabilidade social estratégica e posteriormente do empreendedorismo social e dimensões associadas, procurou-se compreender até que ponto os conceitos estavam relacionados. Dos dois conceitos surge responsabilidade social empresarial e do empreendedorismo social surge o Empreendedorismo Social Empresarial, um processo que visa capacitar os negócios a desenvolver atividades mais avançadas e eficientes de responsabilidade social (Austin & Reficco, 2009). Foi adotada a metodologia de estudo de caso múltiplos, tendo sido analisadas 3 startups sociais. Concluiu-se que a responsabilidade social ao longo dos anos colocou em destaque os problemas sociais e as startups sociais transformaram ideias para sua resolução, em produtos e serviços e que as mesmas apostam em iniciativas de responsabilidade social.
- Chaos analysis and explicit series solutions to the seasonally forced SIR epidemic modelPublication . Duarte, Jorge; Januário, Cristina; Martins, Nuno; Rogovchenko, Svitlana; Rogovchenko, YuriyDespite numerous studies of epidemiological systems, the role of seasonality in the recurrent epidemics is not entirely understood. During certain periods of the year incidence rates of a number of endemic infectious diseases may fluctuate dramatically. This influences the dynamics of mathematical models describing the spread of infection and often leads to chaotic oscillations. In this paper, we are concerned with a generalization of a classical Susceptible–Infected–Recovered epidemic model which accounts for seasonal effects. Combining numerical and analytic techniques, we gain new insights into the complex dynamics of a recurrent disease influenced by the seasonality. Computation of the Lyapunov spectrum allows us to identify different chaotic regimes, determine the fractal dimension and estimate the predictability of the appearance of attractors in the system. Applying the homotopy analysis method, we obtain series solutions to the original nonautonomous SIR model with a high level of accuracy and use these approximations to analyze the dynamics of the system. The efficiency of the method is guaranteed by the optimal choice of an auxiliary control parameter which ensures the rapid convergence of the series to the exact solution of the forced SIR epidemic model.
- Os daltónicos e as suas dificuldades: uma revisão da literaturaPublication . Sousa, L.; Mendanha, Luís; Oliveira, Manuel; Quintino, WilsonA discromatopsia é um termo científico usado para designar qualquer tipo de defeito da visão cromática. A palavra Daltonismo é popularmente usada como sinónimo de discromatopsia, em referência ao químico e cientista John Dalton (1766-1844), que tinha protanopia e foi o primeiro a estudar o tema. As discromatopsias podem ser congénitas ou adquiridas. No caso do defeito congénito os indivíduos apresentam geralmente ambos os olhos acometidos,uma boa acuidade visual, excepto no caso dos monocromatas e não há piora, nem melhora na evolução do defeito com o passar do tempo. No caso do defeito adquirido os indivíduos possuem um ou ambos os olhos acometidos, a sua acuidade visual está comprometida e o defeito pode agravar se ou evoluir para a cura, dependendo da condição/patologia que está afetando a visão cromática.
- Evaluation of urinary protein and creatinine concentration in athletes after high-performance physical exercisePublication . Tavares, Ana Sofia; Ladeira, Carina; Quintão, João Filipe; Luís, Maria Carolina; Pereira, Miguel Oliveira; Abreu, RenatoIntense physical exercise without a planned or structured physical activity can induce potentials risks in the human body. The objective of this study is to verify the existence of a modulation of the values of creatinine and urinary proteins after performing a training session of high intensity. Furthermore, we intend to verify the existence of significant alterations of these analytes in sportsmen who regularly use protein supplementation, compared to a group of athletes who do not use supplementation after performing the same high-performance training. A convenience sample of 18 sportsmen attending gyms, both genders and between the ages of 18 and 35 were divided into two groups: users of protein supplementation (n = 9) and individual non-users of protein supplementation (n = 9). The two groups were subjects to a physical activity training session of high intensity, performed by a qualified professional. Urine samples were collected before and after the training session and proteinuria and creatinuria were analyzed by the Abbott® Architect C8200 system. Statistical treatment of the results was performed using the SPSS (version 22), as well as descriptive and inferential statistics. Results showed that in both groups, physical exercise-induced a significant increase in all these parameters. Both levels of protein and creatinine increased in urine approximately twice more after the physical training with an estimated time of 45 minutes. However, no statistically significant changes were observed from one group to another, although there were slight changes in the user group of protein supplementation.
- Os efeitos sociais e económicos da economia paralela em tempos de crisePublication . Cabral, José Mascarenhas; Mendes, António AlfredoNão será de estranhar que em tempos de crise a economia paralela seja considerada como uma das causas para justificar o incumprimento do objetivo orçamental por insuficiência na obtenção de receitas fiscais, dificultando o cumprimento da missão do estado na prossecução dos seus objetivos de prestação de serviços ao cidadão, não lhe sendo apontada por contraponto quase nenhuma virtude. No entanto, com este trabalho de dissertação pretende-se discutir os principais efeitos da economia paralela, nomeadamente da economia informal nas vertentes social e económica, identificando os seus aspetos nocivos mas também os seus contributos sociais e económicos positivos. Por outro lado as sociedades atuais têm vindo a ter uma preocupação crescente com o Bem-Estar dos seus cidadãos, propondo-se a garantir um conjunto de necessidades que permitam a sua existência com dignidade. Este documento revisa a literatura académica com incidência particular sobre este tema sendo complementado indicadores estatísticos estabelecendo igualmente correlações entre as variáveis em análise. Nesta dissertação, utilizando a metodologia qualitativa, pretende-se concluir que em períodos de crise, apesar dos seus conhecidos aspetos negativos de que sobressaem a concorrência desleal e não igualdade dos cidadãos, a economia paralela, nomeadamente em situações de desemprego ou subemprego, pode ter um papel social relevante para o bem estar das famílias, e igualmente um contributo marginal para a economia. Isto porque grande parte do rendimento obtido por esta via entrará no circuito económico e estará sujeito como o restante às tributações indiretas através do consumo de bens e serviços.
- Acuidade visual, equilíbrio oculomotor e estereopsia nos jovens universitáriosPublication . Fortes, S.; Oliveira, Manuel; Mendanha, Luís; Quintino, Wilson; Graça, N.; Rodrigues, S.A visão tem um papel crucial na vida social, académica e/ou profissional do indivíduo. Deste modo, importante a deteção precoce das possíveis anomalias da função visual, tais como as reduções da acuidade visual, disfunções da Visão Binocular (como insuficiências de convergência, estrabismo, etc.), isso com o intuito de melhorar a qualidade de vida do indivíduo.
- Influence of Re and Ru doping on the structural, optical and photocatalytic properties of nanocrystalline TiO2Publication . Barrocas, Beatriz; Monteiro, Olinda; Nunes, Manuel R.; Silvestre, António JorgeTiO2 and TM-doped TiO2 (TM = Re, Ru) anatase crystalline nanopowders were synthesized by a simple hydrothermal method. Samples with nominal TM/Ti ratio of 0.01 were prepared for this study. Their structural, microstructural and optical properties were studied. The lattice parameters of the different prepared samples were calculated and their mean crystallite sizes determined to be in the range 15–7 nm, the lower values being obtained for the doped crystallites. The samples’ specific surface areas were determined and correlated with their mean crystallite sizes. The incorporation of the dopant elements results in an increase of the optical absorption in the visible range. The samples’ optical bandgap and Urbach energies were calculated from UV–Vis diffuse reflectance spectra. The photocatalytic behavior of the synthesized samples was investigated for the rhodamine B and phenol degradation processes, the kinetics of the different photo-oxidation reactions being also studied. The results showed that doping either with Re or Ru can lead to enhancement of the TiO2 photocatalytic efficiency and that, among the synthesized samples Ru-doped TiO2 is the most efficient photocatalyst for both the Rhodamine B and phenol photodegradation reactions.
- Electrostatic dust cloth to assess occupational exposure to bioburden in primary health care centersPublication . Viegas, Carla; Santos, Patrícia; Almeida, Beatriz; Monteiro, Ana; Carolino, Elisabete; Viegas, SusanaPrimary health care centres (PHCC) in Portugal ensure the prevision of primary health care to the population of a specific geographic area and have a crucial role in health promotion and disease prevention. Surprisingly, there is a gap of information regarding this occupational environment, although bioburden (comprising fungi and bacteria burden) assessment and control in health care facilities is currently a mandatory and vital part of prevention strategies against hospital-acquired infections. A total of 10 primary health care canters located in the city of Lisbon were investigated for the first time. The sample collection was conducted in workstations where was consider a critical risk of occupational exposure to bioburden and active and passive sampling methods were applied. Bioburden collected by the 81 electrostatic dust cloth (EDC) was analyzed by culture based-methods and molecular detection using qPCR targeting 5 different fungi, namely 4 Aspergillus sections (Flavi, Fumigati, Circumdati and Versicolores) and Stachybotrys chartarum complex will be performed shortly. EDC weight, extraction and bioburden characterization by culture based-methods followed the same procedures already described elsewhere. Additionally, particles measurements were performed as in the same previous study. The fungal contamination levels ranged from 0 to 53397.03 CFU.m-2 (workers canteen). Among Aspergillus genera observed, the most prevalent was Aspergillus section Versicolores (0.09%) followed by Nigri (0.03%). Sections Candidi and Fumigati were also isolated in smaller counts (0.01%). The total bacterial contamination ranged from 0 CFU.m-2 to 4670.91 CFU.m-2 (treatment room). A load of Gram-negative bacteria ranged from 0 to 530.79 CFU.m-2. Among other results, statistical correlation analyses suggest that higher EDC weights are related to higher concentrations of the particles 5.0 and higher values of TPM. It was possible to identify the PHCC with higher counts regarding fungal counts (significant differences) through EDC, enabling the decision about the further need to apply different sampling approaches and also to identify potential indoor contamination sources. Thus, EDC can be applied as a screening-method for particles assessment and as a complementary method for assessing bioburden, since it provides a long-term integrated sample, whereas air samples can only reflect the load from a shorter period of time.
- Assessment of azole resistance in clinical settings by passive samplingPublication . Aranha Caetano, Liliana; Almeida, Beatriz; Viegas, CarlaThe exposure to the fungal burden is an increased risk factor for the development of respiratory symptoms and fungal diseases. The emergence worldwide of azole resistance in fungal species is a major concern for public health. Clinical settings must provide a clean and safe environment to protect patients and staff from fungal diseases. The aim of this study was to assess the fungal burden and prevalence of azole resistance in clinical settings in Portugal using passive sampling methods. Ten Primary Health Care Centers were evaluated through passive sampling, including electrostatic dust cloths, heating ventilation, and air conditioning filters, and settled dust. All samples were plated onto Sabouraud dextrose agar media and screened for azole resistance using agar media supplemented with itraconazole, voriconazole and posaconazole through incubation at 27 °C, for 5 days. Fungal species were identified based on macro and micromorphology. Fungal load ranged from 348 to 424628 CFU·m−2 in EDC, 0 to 56500 CFU·m−2 in HVAC filter, and 2 to 514 CFU·g−1 in settled dust. EDC samples presented the highest fungal loads and wider diversity. Azole resistance was observed in all Primary Health Care Centers. Multi-azole resistance (fungal growth in two or more azoles) was observed in 90% units for Penicillium sp., C. sitophila, and Cladosporium sp. None of the samples containing Aspergillus sp. colonies presented resistance to the tested azoles. The knowledge of the fungal burden and prevalence of resistance to azole-based antifungal drugs in clinical environments will allow a better risk characterization regarding fungal burden.
- Characterization of microseismic noise in Cape VerdePublication . Carvalho, Joana; Silveira, Graça; Schimmel, Martin; Stutzmann, EleonoreThe interaction of ocean waves with either the seafloor or other ocean waves generates primary (PM) and secondary microseisms (SM) that propagate through the crust and mantle, predominantly as Rayleigh waves. The horseshoe geometry and surrounding bathymetry of the Cape Verde archipelago play a significant role in the ambient-noise generation in this region. We analyze the microseisms recorded in the region using two different temporary seismic networks, and we determine the number of signals polarized as Rayleigh waves and their back azimuth (BAZ) as a function of time and frequency. The relative number of polarized signals between PM and SM varies between the stations. At most of the stations, the SM can be divided into two frequency bands. At lower frequencies (0.1-0.2 Hz), the number of SM signals is stable throughout the year, whereas at higher frequencies (0.2-0.3 Hz) this number varies with the season, with more polarized signals during the northern hemisphere spring and summer. In both frequency ranges and at most stations, the BAZ does not vary significantly over the year and points toward sources within the archipelago and outside. We compute the source site effect and show that the local bathymetry around the Cape Verde Islands strongly amplifies local SM sources. Finally, we compare the measured BAZ with source areas derived from an ocean-wave model, which confirms that Cape Verde stations mostly record local sources.