O uso do justo valor na mensuração dos activos fixos

Mestrado em Contabilidade, Fiscalidade e Finanças EmpresariaisAs demonstrações financeiras assumem cada vez mais um papel preponderante no processo de tomada de decisão das empresas. Surgem como opções para expressar o valor patrimonial das empresas o Custo Histórico e o Justo Valor. Neste trabalho serão abordados ambas as formas de valorização de ativos, evidenciando as suas vantagens e desvantagens. Através de um modelo com variáveis explicativas (tamanho, sector, alavancagem e rendibilidade) aplicado às empresas do PSI-Geral, verifica-se que a dimensão da empresa não é relevante para a adopção do Justo Valor, as empresas do sector industrial, bem como empresas com maior endividamento são mais propensas ao uso do Justo Valor, e à medida que o ROE aumenta há tendência para as empresas optarem pelo Justo Valor.The financial statements are increasingly taking a leading role in the process of making decision by enterprises. Historical cost and Fair Value appear as options to express the value of the companies. This work will address each of these forms of asset valuation, highlighting their advantages and disadvantages. Through a model with explanatory variables (size, sector, leverage and return-on-equity) applied to enterprises PSI-Geral, it appears that firm size is not relevant to the adoption of the Fair Value, the companies in the industrial sector as well as companies with higher debt are more likely to use the Fair Value, and as ROE increases there is a tendency for companies to opt for Fair Value

Postural control is altered in females with excessive medial knee displacement

Knee valgus motion observed during landing tasks has been proposed as a predictor of future knee injury. It mainly involves excess motion in the frontal plane and is known to be greater in individuals with excessive medial knee displacement (MKD). This affects postural control during sports manoeuvres. Previous sports medicine-related research suggests that the nature of these fluctuations provide rich and more sensitive information to identify risk of (re)injury. We aimed to investigate the fluctuations of the centre of pressure (CoP) in individuals with and without excessive MKD. Twenty females (12 controls; 8 excessive MKD) were instructed to perform single-leg landing tasks from three different directions. The participants landed on a force plate and stayed still for 20 seconds. The fluctuations of the anterior-posterior and medial-lateral directions of the CoP were determined through the calculation of Sample Entropy. Mixed-model ANOVAs (3 [Landing Direction] x 2 [Group]) were used. We have found that only the entropy of the medial-lateral direction was different between groups. Individuals with excessive MKD exhibited an increase in entropy values, indicating greater randomness in CoP fluctuations. This suggests a decreased ability to adapt to environmental demands that likely result in an increased risk of injury

The epidemic emergence of HIV: what novel enabling factors were involved?

Humans acquired retroviruses from simians, mainly through bushmeat handling. All epidemically successful HIV groups started to spread in early 20th century, contrasting with the antiquity of T-cell lymphotropic viruses, implying that novel enabling factors were involved in HIV emergence. Here we review the Parenteral Serial Transmission and the Enhanced Heterosexual Transmission hypotheses for the adaptation and early spread of HIV. Epidemic start roughly coincides in time with peak genital ulcer disease in cities, suggesting a major role for sexual transmission. Only ill-adapted and rare HIV groups emerged after approximately 1950, when injections and transfusions attained their maximal levels, suggesting that if parenteral serial transmission was necessary for HIV adaptation, it had to be complemented by sexual transmission for HIV to reach epidemic potential

Personality and well-being in adolescents

Different profiles of the character dimensions of self-directedness, cooperativeness and self-transcendence result in different levels of wellbeing among adults. However, the description of the multidimensional character profiles on adolescents’ composite wellbeing remains unexplored. This study builds on previous studies with adults, and examines the linear and non-linear associations between the dimensions of the psychobiological model of personality and well-being in adolescents. Participated in this study 1540 adolescents (M=15.44, SD=1.731). Personality was assessed using the Temperament and Character Inventory (TCI). Well-being was evaluated in a composite perspective: satisfaction with social support, health-related quality of life, satisfaction with life and affect. Variable-centered and individual-centered analyses were performed.Self-directedness was strongly associated with all dimensions of affective and cognitive well-being regardless of the other two character traits. Cooperativeness was associated with non-affective well-being and with positive affect, but only when associated to elevation of Self-directedness and Self-transcendence. Self-Directedness and Cooperativeness explained 15.5% of the non-affective well-being variance. Self-Directedness and Self-Transcendence explained 10.4% of the variance in affective well-being. This study confirms the tendencies found in previous studies with adults from other societies, where each character dimension gives an independent contribution to well-being depending on the interactions with other Character dimensions. Also, this study highlights the importance of considering the non-linear influences of the character dimensions in understanding of adolescents’ wellbeing. These results have strong implications for youth positive mental health promotion, including for school-based policies and practices

PLSR Models for Mechanical Strengths of Concrete Composite Materials Reinforced with Pultrusion Wastes

In this paper, we present two Partial Least Squares Regression (PLSR) models for compressive and flexural strength responses of a concrete composite material reinforced with pultrusion wastes. The main objective is to characterize this cost-effective waste management solution for glass fiber reinforced polymer (GFRP) pultrusion wastes and end-of-life products that will lead, thereby, to a more sustainable composite materials industry. The experiments took into account formulations with the incorporation of three different weight contents of GFRP waste materials into polyester based mortars, as sand aggregate and filler replacements, two waste particle size grades and the incorporation of silane adhesion promoter into the polyester resin matrix in order to improve binder aggregates interfaces. The regression models were achieved for these data and two latent variables were identified as suitable, with a 95% confidence level. This technological option, for improving the quality of GFRP filled polymer mortars, is viable thus opening a door to selective recycling of GFRP waste and its use in the production of concrete-polymer based products. However, further and complementary studies will be necessary to confirm the technical and economic viability of the process

Re-use assessment of thermoset composite wastes as aggregate and filler replacement for concrete-polymer composite materials: a case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites

Influence of water and nutrients on cork oak radial growth – looking for an efficient fertirrigation regime

The widespread cork oak (Quercus suber L.) mortality and reduced afforestation /regeneration are causing an overall reduction in cork production. To enhance trees’ growth and vitality, afforestation techniques using fertirrigation were tested. The main objective was the promotion of trees’ growth on new dense plantations using minimum water requirements until reaching productive forests. The experimental plot – Irricork – was installed in 2017 in a ≈1 ha stand with 14 years’ age cork oaks summer-fertirrigated since plantation. Four fertirrigation treatments were applied during fertirrigation campaigns. Radial growth, meteorological parameters and fertirrigation volume were measured every 15–30 days over four years. It was observed that weather, tree size, debarking and trees’ intra-competition had a significant effect on radial increments. Fertirrigation significantly enhanced growth during summer drought and decoupled increments from air vapor pressure deficit constraints. There was a linear relationship between trees’ radial increments and fertirrigation volume up to 140 m3 week–1. Above this value, increments were smoother. In conclusion, summer fertirrigation of 140 m3 week–1 efficiently enhanced the radial growth of trees with 50–75 circumference at breast height, under the particular edaphoclimatic conditions of the stand. This study showed to be, therefore, promising in the use of efficient fertirrigation the enhance cork oaks’ radial growth

Massive introgression drives species radiation at the range limit of Anopheles gambiae

Impacts of introgressive hybridisation may range from genomic erosion and species collapse to rapid adaptation and speciation but opportunities to study these dynamics are rare. We investigated the extent, causes and consequences of a hybrid zone between Anopheles coluzzii and Anopheles gambiae in Guinea-Bissau, where high hybridisation rates appear to be stable at least since the 1990s. Anopheles gambiae was genetically partitioned into inland and coastal subpopulations, separated by a central region dominated by A. coluzzii. Surprisingly, whole genome sequencing revealed that the coastal region harbours a hybrid form characterised by an A. gambiae-like sex chromosome and massive introgression of A. coluzzii autosomal alleles. Local selection on chromosomal inversions may play a role in this process, suggesting potential for spatiotemporal stability of the coastal hybrid form and providing resilience against introgression of medically-important loci and traits, found to be more prevalent in inland A. gambiae

Glycerol ethers as hydrotropes and their use to enhance the solubility of phenolic acids in water

The use of glycerol ethers (with alkyl side chain ranging from one to six methyl groups) as hydrotropes to enhance the solubility of gallic and syringic acids in water was here studied. These compounds were selected by their intrinsic interest and for serving as models for lignin fractions. The results obtained were compared against traditional co-solvents, demonstrating the exceptional hydrotropic ability of glycerol ethers. Setschenow constants show that the hydrophobicities of both solute and hydrotrope play an important role in the solubility enhancement by hydrotropy, shedding light into its molecular mechanism