853 research outputs found

    Mode of action of the hemin-controlled inhibitor of protein synthesis

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    Despite the finding that the hemin-controlled translational inhibitor in reticulocyte lysates is a cyclic AMP-independent protein kinase that phosphorylates the small subunit of the initiation factor eIF-2, the mechanism of inhibition of translation remained unexplained. Whereas treatment of hemin-containing lysates with inhibitor in the presence of ATP inhibited translation, the same treatment of highly purified eIF-2 did not affect its ability to form a ternary complex with initiator Met-tRNA and GTP or a 40S initiation complex. We have isolated from ribosomal salt washes a protein (eIF-2 stimulating protein) that enhances the capacity of unphosphorylated eIF-2 to form ternary or 40S initiation complexes but has no effect on the phosphorylated factor. At low concentrations, eIF-2 is virtually inactive without this stimulating protein. Therefore, the translational inhibitor acts by converting eIF-2 to a form that is not stimulated by the stimulating protein

    A Robust Real-Time Automatic License Plate Recognition Based on the YOLO Detector

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    Automatic License Plate Recognition (ALPR) has been a frequent topic of research due to many practical applications. However, many of the current solutions are still not robust in real-world situations, commonly depending on many constraints. This paper presents a robust and efficient ALPR system based on the state-of-the-art YOLO object detector. The Convolutional Neural Networks (CNNs) are trained and fine-tuned for each ALPR stage so that they are robust under different conditions (e.g., variations in camera, lighting, and background). Specially for character segmentation and recognition, we design a two-stage approach employing simple data augmentation tricks such as inverted License Plates (LPs) and flipped characters. The resulting ALPR approach achieved impressive results in two datasets. First, in the SSIG dataset, composed of 2,000 frames from 101 vehicle videos, our system achieved a recognition rate of 93.53% and 47 Frames Per Second (FPS), performing better than both Sighthound and OpenALPR commercial systems (89.80% and 93.03%, respectively) and considerably outperforming previous results (81.80%). Second, targeting a more realistic scenario, we introduce a larger public dataset, called UFPR-ALPR dataset, designed to ALPR. This dataset contains 150 videos and 4,500 frames captured when both camera and vehicles are moving and also contains different types of vehicles (cars, motorcycles, buses and trucks). In our proposed dataset, the trial versions of commercial systems achieved recognition rates below 70%. On the other hand, our system performed better, with recognition rate of 78.33% and 35 FPS.Comment: Accepted for presentation at the International Joint Conference on Neural Networks (IJCNN) 201

    Chrono-Nutrition: The Relationship between Time-of-Day Energy and Macronutrient Intake and Children's Body Weight Status

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    The time of eating has been considered to have an important role in weight regulation. However, it is unknown if there are specific daily patterns of energy and macronutrient distribution that could be more beneficial for metabolic outcomes, especially obesity. This study aimed to assess the effect of time-of-day energy and macronutrient intake at 4 y of age on the weight status at 7 y of age. The study sample included 1961 children from the population-based birth cohort Generation XXI, with data on 3-day food diaries at 4 y and body mass index (BMI) z-scores at 7 y. Dietary patterns based on the collected data were obtained for the distribution of energy and macronutrients across eating occasions. Having a relatively higher energy intake at lunch and supper (OR = 1.19, 95% CI = 1.05 to 1.34) or at mid-afternoon (OR = 1.18, 95% CI = 1.05 to 1.34) at 4 y was associated with higher odds of becoming overweight/obese at 7 y. A relatively higher intake of fat at lunch was positively associated with later children’s odds for being overweight or obese (OR = 1.17, 95% CI = 1.03 to 1.32). These associations were independent of the effect on children’s eating behaviors related to appetite. Our results also show a detrimental relation between skipping breakfast and eating late in the day and children’s body weight. Considering all daily eating occasions, a higher proportion of energy and macronutrient intake at the main meals and a lower proportion during the afternoon and evening seems to be more beneficial for children’s weight. These results emphasize the important role of daily food intake rhythm on excessive weight gain in childhood

    Demanda hídrica e eficiência de uso da água pelo arroz: influência do período de supressão da irrigação.

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    Effectiveness of repetitive influenza vaccination against SARS-CoV-2 infection among a cohort of health care workers in Portugal

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    Vaccination for influenza has been essential over the years to protect the most vulnerable populations. Moreover, it was recently suggested that influenza vaccination might confer some nonspecific immunity to other viruses and be associated with a lower risk for coronavirus disease 2019 (COVID-19) morbidity and mortality. Therefore, we aimed to assess the effectiveness of repetitive influenza vaccination against SARS-CoV-2 infection in a cohort of health care workers (HCWs). This study was conducted among HCWs at São João University Hospital Center (CHUSJ), Porto, Portugal, a tertiary reference hospital for diagnosis and therapy, one of the largest hospitals in the country with approximately 6000 HCWs. We analyzed databases for influenza vaccination conducted between 2012 and 2019 and COVID-19 laboratory testing retrieved from the first and last registered positive COVID test date before HCW's COVID-19 vaccination started. The study outcome was the incidence of the first SARS-CoV-2 infection, as determined by reverse transcription polymerase chain reaction (RT-PCR). Age and sex were considered potential confounders. We used multivariable Cox regression to estimate odds ratios. Neither the absolute number nor the proportion of influenza shots influenced the risk of getting infected by SARS-CoV-2 (adjusted odds ratio 1.02, 95% CI: 0.9–1.06 and 1.17 95% CI: 0.86–1.58, respectively). Similar findings were observed in most cases when the analysis was restricted by year. The findings from our retrospective observational analysis of a HCWs cohort failed to support any protective effect between repetitive influenza vaccination and SARS-CoV-2 infection

    Scaling of spontaneous rotation with temperature and plasma current in tokamaks

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    Using theoretical arguments, a simple scaling law for the size of the intrinsic rotation observed in tokamaks in the absence of momentum injection is found: the velocity generated in the core of a tokamak must be proportional to the ion temperature difference in the core divided by the plasma current, independent of the size of the device. The constant of proportionality is of the order of 10 km⋅s−1⋅MA⋅keV−110\,\mathrm{km \cdot s^{-1} \cdot MA \cdot keV^{-1}}. When the intrinsic rotation profile is hollow, i.e. it is counter-current in the core of the tokamak and co-current in the edge, the scaling law presented in this Letter fits the data remarkably well for several tokamaks of vastly different size and heated by different mechanisms.Comment: 5 pages, 3 figure

    Development and validation of predictive equations for spirometry in Portuguese children

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    Background There are no data on lung function reference values for Portuguese children, and the contribution from the Portuguese data set in the Global Lung Function Initiative (GLI) is scant. Objectives We aimed to estimate new up-to-date reference values for Portuguese children by fitting a multivariable regression model to a general population sample. Further, we intended to assess the external validity of the obtained reference values and to compare them to the GLI reference values. Methods A random sample of 858 children from 20 primary schools were screened by health questionnaire, physical examination, and spirometry. Spirometric parameters recorded were FVC, FEV1, and FEF25-75. Multiple regression models were used to derive reference equations. Results Overall, 481 children, aged between 7 and 12 years, 267 boys (55.5%), were included. Boys had higher values for FVC and FEV1 than girls (P < .05). The strongest correlation was found for FVC with height (r = 0.71 for boys and 0.70 for girls), while the lowest correlation was observed in both sexes for FEF25-75 with age (r = 0.23). Height was the most significant predictor of FVC, FEV1, and FEF25-75 in our models. Weight and body mass index were not significant predictors for boys but had a significant effect on girls’ equations for all spirometry parameters. Compared to obtained reference equations with GLI, they performed better for FVC in boys, FEV1 in girls, and FEF25-75 in both boys and girls. Conclusion We offer up-to-date reference values of spirometry for Portuguese children that can be used in clinical practice and research.Deriving cohort was funded by Project NORTE-01-0145-FEDER-000010 – Health, Comfort and Energy in the Built Environment (HEBE), cofinanced by Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER and of the Foundation for Science and Technology schoolarships SFRH/BD/108605/2015 and SFRH/BD/112269/2015. Validating cohort was funded by Programa Operacional de Saúde – Saúde XXI, Quadro Comunitário de Apoio III and by Administração Regional de Saúde do Norte. For follow-up assessments Generation XXI received funding from Fundação para a Ciência e a Tecnologia (PTDC/SAU-ESA/108577/ 2008), co-funded by FEDER through COMPETE and from Fundação Calouste Gulbenkian. This work was supported by national funds through FCT – Fundação para a Ciência e Tecnologia, I.P., under the projects 2022.07363.PTDC, UIDB/04750/2020 and LA/P/0064/2020. Generation XXI was funded by Programa Operacional de Saúde – Saúde XXI, Quadro Comunitário de Apoio III and Administração Regional de Saúde Norte (Regional Department of Ministry of Health)

    Application of a Latent Transition Model to Estimate the Usual Prevalence of Dietary Patterns

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    Background: This study aims to derive habitual dietary patterns of the Portuguese adult population by applying two methodological approaches: a latent class model and a latent transition model. The novel application of the latent transition model allows us to determine the day-to-day variability of diet and to calculate the usual prevalence of dietary patterns. Methods: Participants are from the National Food, Nutrition and Physical Activity Survey of the Portuguese population, 2015-2016 (2029 women; 1820 men, aged >= 18 years). Diet was collected by two 24 h dietary recalls (8-15 days apart). Dietary patterns were derived by: (1) a latent class model using the arithmetic mean of food weigh intake, with concomitant variables (age and sex); (2) a latent transition model allowing the transition from one pattern to another, with the same concomitant variables. Results: Six dietary patterns were identified by a latent class model. By using a latent transition model, three dietary patterns were identified: "In-transition to Western" (higher red meat and alcohol intake; followed by middle-aged men), "Western" (higher meats/eggs and energy-dense foods intake; followed by younger men), and "Traditional-Healthier" (higher intake of fruit, vegetables and fish, characteristic of older women). Most individuals followed the same pattern on both days, but around 26% transited between "In-transition to Western" and "Western". The prevalence of the dietary patterns using a single recall day (40%, 27%, 33%, respectively) is different from the usual prevalence obtained by the latent transition probabilities (48%, 36%, 16%). Conclusion: Three dietary patterns, largely dependent on age and sex, were identified for the Portuguese adult population: "In-transition to Western" (48%), "Western" (36%), and "Traditional-Healthier" (16%), but 26% were transient between patterns. Dietary patterns are, in general, deviating from traditional habits
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