Browsing by Author "Santos, R."
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- Angular distributions in $t \overline{t}H(H → b \overline{b})$ reconstructed events at the LHCPublication . Amor dos Santos, S. P.; Araque, J.P.; Cantrill, R.; Castro, N.F.; Fiolhais, M.C.N.; Frederix, R.; Gonçalo, R.; Martins, R.; Santos, R.; Silva, J.; Onofre, A.; Peixoto, H.; Reigoto, A.The associated production of a Higgs boson and a top-quark pair, $t{\bar t} H$, in proton-proton collisions is addressed in this paper for a center of mass energy of 13TeV at the LHC. Dileptonic final states of $t{\bar t}H$ events with two oppositely charged leptons and four jets from the decays $t\rightarrow bW^+ \rightarrow b \ell^+\nu_\ell$, $\bar{t}\rightarrow \bar{b}W^- \rightarrow \bar{b} \ell^-\bar{\nu}_\ell$ and $h\rightarrow b\bar{b}$, are used. Signal events, generated with MadGraph5_aMC@NLO, are fully reconstructed by applying a kinematic fit. New angular distributions of the decay products as well as angular asymmetries are explored in order to improve discrimination of $t{\bar t} H$ signal events over the dominant irreducible background contribution, $t{\bar t}b{\bar b}$. Even after the full kinematic fit reconstruction of the events, the proposed angular distributions and asymmetries are still quite different in the $t\bar{t}H$ signal and the dominant background ($t\bar{t}b\bar{b}$).
- ARHL and Tinnitus in Portuguese Population: what we can hear from a sample of elderly individuals.Publication . Flook, M.; Lopes, S.; Aparicio, M.; Santos, R.; Andrade, C.; Andrade, S.; Martins, J.; O'Neill, A.; Escada, P.; Argüello, Patricia; Alcântara, P.; O'Neill, J.; Villaverde Cabral, M.; Antunes, M.; Matos, T.; Fialho, G.; Caria, H.
- Designing an early selection morphological traits index for reproductive efficiency in Pura Raza Española maresPublication . Perdomo-González, Davinia I; Sánchez-Guerrero, María J; Bartolomé, Ester; Santos, R.; Molina, Antonio; Valera, MercedesThe low rate of reproductive efficiency in horses may be linked to the equine industry’s practice of maintaining breeding stock that stands out for its athletic or morphological performance but exhibits poor reproductive efficiency. In this study, the age at first foaling, age at last foaling, interval between first and second foaling, average interval between foaling, foaling number and reproductive efficiency, and their relationship with the morphological records in 19,758 Pura Raza Española (PRE) mares were analyzed. After a partial least squares analysis height at withers, lateral hock angle, dorsal-sternal diameter, perimeter of anterior cannon bone, angle of shoulder, thoracic perimeter, hip-stifle distance, and angle of croup were the most important traits related with reproductive traits in PRE mares. A multivariate animal model with both morphological and reproductive traits was applied, including age, geographical area, coat color, and average stud size in the decade of the mare’s first foaling. The results indicate that reproductive selection is feasible, and is enhanced by the use of morphological traits, given the moderate to high magnitudes of heritability values in both types of traits, which oscillated between 0.1 (interval between first and second foaling) and 0.95 (height at withers). The resulting genetic parameters were used to develop a series of selection indexes based on morphological or morphological and reproductive combination traits to improve reproductive efficiency traits in PRE mares and thus compute the expected genetic response (EGR) for the different strategies. The increase in EGR, when comparing EGR using only reproductive traits as selection criteria vs. using a combined index of both morphological and reproductive traits, oscillated between 4.0% for the age at first foaling to 46.8% for the interval between first and second foaling. In addition, two precocity indexes showed positive EGR when the age at last foaling and the interval between first and second foaling, both with and without morphological traits, were used as selection criteria. Therefore, this analysis reveals that the preselection of reproductive traits based on morphological traits is possible in PRE mares. Ultimately, this knowledge will help breeders achieve genetic progress in reproductive traits, leading to healthier and more successful breeding outcomes in horses.
- Hydration status using free water reserve in Portuguese adolescentsPublication . Gonçalves, C.; Padrão, P.; Abreu, S.; Graça, Pedro; Santos, R.; Moreira, P.Introduction: Few data is available about the hydration status of active adolescents in free living conditions. Cell dehydration may be prevalent in healthy, free-living children at school and they could be in a state of chronic voluntary dehydration. Objective: This study aims to describe hydration status assessed by Free Water Reserve (FWR) in adolescents. Method: Two hundred participants (118 girls), aged 13-18 years completed the study. Urinary volume (ml/d) and urinary osmolality (mosm/kg) were measured by one 24h urinary collection, and coefficient of creatinine was used to validate completeness of urine collections. FWR (measured urine volume minus the obligatory urine volume) was used for characterization of hydration status. Positive values of FWR indicate euhydration, negative values the risk of hypo-hydration. Results: Median urinary volume excretion was 1100.0 ml/d for boys and 1025.0 ml/d for girls (p=0.923). Mean urinary osmolality was 715.7±172.3 mosm/kg for boys and 597.42±193.1 mosm/kg for girls (p=0.247). Median FWR (ml/24h) was positive in both sex groups (173.2 ml/d in boys and 373.2 ml/d in girls); however, 40.2% of boys and 31.4% of girls (p=0.195) were at risk of hypo-hydration status. Conclusions: In this sample of adolescents approximately one third was classified as at risk of hypo-hydration status. Preventive measures to increase the level of total water intake should be considered.
- Medico-legal age estimation in a sub-adult portuguese population: validation of Atlas Schour and Massler and LondonPublication . Cesário, C.; Santos, R.; Pestana, D.; Pereira, Cristiana Palmela"Introduction: Age estimation in children and adolescents often depends on morphological methods, such as examination of dental development. Objectives: The aim of this project was to validate, in a Portuguese population, two forensic methods of dental age estimation – Schour and Massler charts and the London atlas. Materials and Methods: The test sample was composed by 108 dental radiographs of living and known-age individuals. Dental age was estimated according to each method. Chronological age was then compared to the estimated dental age using individual t-test and paired t-test. Results: Results showed that the Schour and Massler charts underestimated age and the London atlas overestimated age. Nevertheless, the London atlas performed better in all measures. Mean differences for both the London atlas and Schour and Massler were 0,1389 and -5,4167 months respectively. Schour and Massler charts showed significant statistical difference between dental age and chronological age (p <0.05). Discussion and Conclusions: We conclude that, in the evaluated sample, age estimation using the London atlas represents an improvement in forensic age estimation from developing teeth. Further studies should be done with a larger Portuguese population sample."
- Prevalence of Lower Back Pain in Portuguese Equestrian RidersPublication . Duarte, Carlota; Santos, R.; Fernandes, Orlando; Raimundo, Armando; Autor correspondente: Santos, R..Lower back pain is prevalent in equestrian athletes, but its prevalence and associated factors are unknown in the Portuguese equestrian population. A questionnaire regarding lower back pain and possible associated factors was answered by 347 respondents. Of the respondents, 214 (61.7%) stated having experienced lower back pain in the past 12 months and therefore completed the Roland Morris disability questionnaire. Among the latter, 63.1% stated that lower back pain impaired their performance. The probability of suffering from lower back pain was higher in individuals with higher weekly riding workloads, who reported equestrianism as their main occupation, and who performed daily stable duties. Considering a Roland Morris disability score of 4 as the cut-off value for dysfunction, this sample had an average score of 5.39 ± 4.42. Individuals who stated equestrianism was their main occupation showed a significantly higher risk (OR = 1.759, p = 0.041) of exhibiting a score ≥ 4 than those who stated equestrianism as a hobby. Age (p = 0.029), body mass index (p = 0.047), and daily performance of stable duties (p = 0.030) were also associated with a higher Roland Morris disability score. Further research is needed to understand the full impacts of lower back pain in Portuguese equestrian athletes.
- Probing the CP nature of the Higgs coupling in $t{\bar t}h$ events at the LHCPublication . Amor Dos Santos, S.; Fiolhais, M.C.N.; Frederix, R.; Gonçalo, R.; Gouveia, E.; Martins, R.; Onofre, A.; Pease, C.M.; Peixoto, H.; Reigoto, A.; Santos, R.; Silva, J.The determination of the CP nature of the Higgs coupling to top quarks is addressed in this paper, using tt¯h events produced in s=13 TeV proton-proton collisions at the LHC. Dileptonic final states are employed, with two oppositely charged leptons and four jets, corresponding to the decays t→bW+→bℓ+νℓ, t¯→b¯W-→b¯ℓ-ν¯ℓ, and h→bb¯. Pure scalar (h=H), pure pseudoscalar (h=A), and CP-violating Higgs boson signal events, generated with MadGraph5_aMC@NLO, are fully reconstructed through a kinematic fit. We furthermore generate samples that have both a CP-even and a CP-odd component in the tt¯h coupling in order to probe the ratio of the two components. New angular distributions of the decay products, as well as CP angular asymmetries, are explored in order to separate the scalar from the pseudoscalar components of the Higgs boson and reduce the contribution from the dominant irreducible background, tt¯bb¯. Significant differences between the angular distributions and asymmetries are observed, even after the full kinematic fit reconstruction of the events, allowing to define the best observables for a global fit of the Higgs couplings parameters.