3,714 research outputs found
A probable early 16th century colonial shipwreck in the Portuguese coast
UIDB/04666/2020 UIDP/04666/2020The Ria de Aveiro F site was discovered during preventive archaeological works carried out in the scope of the 2002 expansion of Aveiro’s harbour into the Ria de Aveiro, a lagoon system located in northern Portugal which played a great role in the salt trade of the Early Modern period. Despite the global destruction of the context caused by the dredging works, several well preserved structural elements were recovered. They belonged to two ships, a carvel-built one and a clinker-built one. The former features several construction characteristics that are common in the Mediterranean. The latter possibly corresponds to a small support boat. Beside the structural findings, several rigging elements wooden and rope artifacts, some pottery shards, ballast stones and a limestone cannonball were also recovered. The global study of the findings allowed to assign these remains to a chronology around the first half of the 16th century. Wood identification analysis were recently carried out; the results indicate the use of tropical, South American species in the construction of the clinker-built vessel. This data allows us to suggest that this site may belong to an initial phase of the relationship between the Americas and the Iberian Peninsula.publishersversionpublishe
Angiogenesis and Breast Cancer
Angiogenesis is an essential step for breast cancer progression and dissemination. The development of new blood vessels in cancer setting (angiogenesis) is conducted by numerous physiological and pathological stimuli, where the main stimulus is hypoxia. The knowledge of different molecular pathways regulating angiogenesis is constantly growing. An increased and complex scenario of angiogenesis is nowadays available in breast cancer, specifically, and permits not only to understand most of the important phases of neoplastic growth but also offer an exciting perspective for new therapeutic proposals based on blocking new blood vessels sprouting. This review focused on historical and recent understanding of angiogenesis occurrence in breast cancer
Numerical modeling and optimization of an air handling unit
Concerns about the efficiency of Heating, Ventilating, and Air Conditioning systems, including Air Handling Units (AHUs), started in the last century due to the energy crisis. Thenceforth, important improvements on the AHUs performance have emerged. Among the various improvements, the control of the AHUs and the redesign of the fans are the most important ones. Although, with increasingly demanding energy efficiency requirements, other constructive solutions must be investigated. Therefore, the objective of this work is to investigate, using a computational fluid dynamics (CFD) tool, the fluid flow inside an AHU and to analyze different constructive solutions in order to improve the AHU performance. The numerical model provided a reasonable agreement with the experimental results in terms of air flow rate, despite the assumed simplifications. Regarding the constructive solution concept, the CFD results for the two different flow control units (FCUs) showed improvements in terms of fan static pressure rise. Under real conditions, improvements of 15.1% when compared with the case without the FCU were obtained. Nevertheless, it was concluded that the axial component of the air velocity, at the fan exit, can have a determinant impact on the FCU viability. Finally, an improved FCU geometry, with a new body shape, which resulted in an additional improvement of 6.1% in the fan static pressure rise.The second author would like to express his gratitude for the support given by FCT through the Grant SFRH/BD/130588/2017
Using analog ensembles with alternative metrics for hindcasting with multistations
This study concerns making weather predictions for a location where no data is available, using
meteorological datasets from nearby stations. The hindcast with multiple stations is performed with
different variants of the Analog Ensemble (AnEn) method. In addition to the traditional Monache
metric used to identify analogs in datasets from one or two stations, several new metrics are explored, namely cosine similarity, normalization, and k-means clustering. These were analyzed and
benchmarked to find the ones that bring improvements. The best results were obtained with the
k-means metric, yielding between 3% and 30% of lower quadratic error when compared against
the Monache metric. Also, by making the predictors to include two stations, the performance of
the hindcast improved, decreasing the error up to 16%, depending on the correlation between the
predictor stations.info:eu-repo/semantics/publishedVersio
Computational Fluid Dynamics Modeling of Ammonia Concentration in a Commercial Broiler Building
In the present study, a numerical model was developed to predict the flow pattern inside a broiler building. The model intends to predict the velocities fields inside the domain and am-monia (NH3) emitted or released by litter from poultry housing. The numerical model developed in Computational Fluid Dynamics (CFD) commercial code, intends to represent a commercial broiler building, and intends to simulate the 3D and heat transfer, in steady state flow. The evaporative cooling pads were also included in the model. The validation of the model was based in experimental measurements obtained in previous studies. The simulations were fo-cused on Summer, Winter and also Mid-Season situation. The numerical results of NH3 concen-tration were compared with the experimental measurements, and a quite good agreement was verified. The numerical results allowed the characterization of: the inside flow pattern devel-oped for the summer and winter situation; the inside NH3 distribution, and the velocity field distribution inside the broiler building. It was found that NH3 concentration increases along the tunnel, especially in low flow rate imposed from the exhaust fan. Also, it was verified that the low velocities inside domain are no sufficient to remove the gaseous pollutants.info:eu-repo/semantics/publishedVersio
Tell me who your friends are?! The mediating role of friends use in cannabis abuse
Objective: To evaluate the relationship between onset age of cannabis use and cannabis abuse testing the mediating role of the number of friends using cannabis with a sample of Portuguese cannabis users. Comparing men and women regarding these relationships. Method: A sample of 529 Portuguese cannabis users, composed of 276 men and 244 women, aged from 14 to 21 years, completed a sociodemographic questionnaire, the Cannabis Abuse Screening Test and four questions related to cannabis use. Data were analyzed using the PROCESS macro in SPSS version 26.0. Results: The onset age of cannabis use was negatively related to the number of friends using cannabis, while the number of friends using cannabis showed a positive relationship with cannabis abuse. As predicted, the number of friends using cannabis seems to have a mediating role in the relationship between the onset age of cannabis use and cannabis abuse since the indirect effect was found to be significant. The pattern of the relationships among the variables observed was found to be similar both for the male and women' samples. However, males reported higher cannabis abuse than females. Conclusion: Results highlight the mediating role of the friends' using cannabis in the relationship between the onset age of cannabis use and users' abuse. Results highlight the importance of early intervention to cannabis use. Particularly, the pattern of the relationships observed among the studied variables emphasized the need to monitor and peer training intervention or the promotion of social skills.info:eu-repo/semantics/acceptedVersio
Conjugated linoleic acid reduces permeability and fluidity of adipose plasma membranes from obese Zucker rats
NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. July 2010; 398 (2): 199-204.Conjugated linoleic acid (CLA) is a dietary fatty acid frequently used as a body fat reducing agent whose effects upon cell membranes and cellular function remain unknown. Obese Zucker rats were fed atherogenic diets containing saturated fats of vegetable or animal origin with or without 1% CLA, as a mixture of cis(c)9,trans(t)11 and t10,c12 isomers. Plasma membrane vesicles obtained from visceral adi- pose tissue were used to assess the effectiveness of dietary fat and CLA membrane incorporation and its outcome on fluidity and permeability to water and glycerol. A significant decrease in adipose membrane fluidity was correlated with the changes observed in permeability, which seem to be caused by the incor- poration of the t10,c12 CLA isomer into membrane phospholipids. These results indicate that CLA supple- mentation in obese Zucker rats fed saturated and cholesterol rich diets reduces the fluidity and permeability of adipose membranes, therefore not supporting CLA as a body fat reducing agent through membrane fluidification in obese fat consumers
Post-traumatic stress disorder in the military police of Rio de Janeiro: can a risk profile be identified?
Background: Significant exposure to critical incidents characteristic of military police work has a potentially traumatic effect and multiple consequences for the mental health of these professionals, such as Post Traumatic Stress Disorder (PTSD). This study aims to investigate the occurrence of PTSD in this occupational group and its correlations with socio-demographic and occupational variables. Methods: This is a cross-sectional study of Rio de Janeiro’s Military Police officers (n = 3.577). Data was collected from self-reported questionnaires applied in an institutional health program. Post-Traumatic Stress Disorder Checklist—Civilian version was used to assess PTSD. Results: Rates of 16.9% for full PTSD and 26.7% for partial PTSD were found. Based on logistic regression analysis, female officers and police officers in lower ranks of the military hierarchy and performing administrative duties were found to be at most risk of developing PTSD. Conclusions: These results suggest the need to further understand the predictive organizational and individual variables of PTSD correlated with the increased vulnerability of professionals in order to contribute to institutional policies for the prevention and rehabilitation of these cases.info:eu-repo/semantics/publishedVersio
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