124 research outputs found

    Optical gas sensing with liquid crystal droplets and convolutional neural networks

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    UIDB/50009/2020 UIDB/ 04378/2020 SCENT-ERC-2014-STG-639123, 2015-2022Liquid crystal (LC)-based materials are promising platforms to develop rapid, miniaturised and low-cost gas sensor devices. In hybrid gel films containing LC droplets, characteristic optical texture variations are observed due to orientational transitions of LC molecules in the presence of distinct volatile organic compounds (VOC). Here, we investigate the use of deep convolutional neural networks (CNN) as pattern recognition systems to analyse optical textures dynamics in LC droplets exposed to a set of different VOCs. LC droplets responses to VOCs were video recorded under polarised optical microscopy (POM). CNNs were then used to extract features from the responses and, in separate tasks, to recognise and quantify the vapours exposed to the films. The impact of droplet diameter on the results was also analysed. With our classification models, we show that a single individual droplet can recognise 11 VOCs with small structural and functional differences (F1-score above 93%). The optical texture variation pattern of a droplet also reflects VOC concentration changes, as suggested by applying a regression model to acetone at 0.9–4.0% (v/v) (mean absolute errors below 0.25% (v/v)). The CNN-based methodology is thus a promising approach for VOC sensing using responses from individual LC-droplets.publishersversionpublishe

    Effects of bodyweight neuromuscular training with and without instability on balance control in active universitarians

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    The purpose of this study was to analyse the effects of a nine-week unstable vs stable bodyweight neuromuscular training programme on balance control. Seventy-seven physically active universitarians were randomly distributed into an unstable training group (UTG), a stable training group (STG), and a control group (CG). The intervention was conducted three times a week for nine weeks. Pre- and post-intervention assessments included static balance control under an unstable surface (eyes open (EOFS), eyes closed (ECFS), challenging visual-vestibular system (CVVS)), assessed as centre-of pressure fluctuations with a force plate. A mixed ANOVA was performed to test the within- and between-subjects factors. After the intervention, no significant differences were found between groups. All groups presented significant improvements in balance measurements in EOFS (p = 0.01), ECFS (p = 0.01; p = 0.02), and CVVS (p = 0.01) conditions. The training groups tended to have significantly better balance control (antero-posterior) than the CG on EOFS. In the CVVS condition, the UTG tended to have better balance control than the CG. There was no overall significant train ing advantage gained by using unstable or stable surfaces in terms of the improvement in static balance control in active universitar ians. Both training groups exhibited similar training adaptations.D915-7373-ED16 | Cesar LeaoN/

    Structural changes in intestinal enteroendocrine cells after ileal interposition in normal rats

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    INTRODUCTION: No therapeutic approach has significantly impacted the progression of diabetes. As early improvement of glicaemic control is observed after bariatric surgeries, there is currently a search for surgical procedures that can promote euglycemia also in non-obese patients. Glicaemic control can be achieved by increasing the blood concentration of GLP-1, a hormone produced by L cells that are more densely concentrated in the terminal ileum. The interposition of ileal segment to a more anterior region (proximal jejunum) can promote a greater stimulation of the L cells by poorly digested food, increasing the production of GLP-1 and reflecting on glicaemic control.
AIMS: To investigate long-term histological modifications of intestinal mucosa of rats submitted to interposition of ileum segment to a proximal region (jejunum).
METHODS: Forty 8-week old male Wistar-EPM1 rats (Rattus norvegicus albinus) were randomly distributed into 3 groups: the Interposition Group (IG) was subjected to ileal interposition, the Sham Group (SG) was subjected to sham operations, and the Control Group (CG) was not subjected to surgery. All animals were followed until the 60th postoperative day (8 postoperative week) when they were euthanized. Segments of jejunum and ileum from all groups were collected and analyzed by optical microscopy and immunohistochemistry.
RESULTS: No structural nor histological changes in intestinal L cells in the interposed intestinal segment and other intestinal segments were noted after ileal interposition surgery. 
CONCLUSION: As L cells endocrine characteristics were likely maintained, the use of metabolic surgical techniques for the treatment of metabolic diseases, especially diabetes, seems to be justified

    The relationship between static and dynamic balance in active young adults

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    Purpose. The objectives were to analyse differences of static and dynamic balance between sexes and test the correlations between static and dynamic balance measures. Methods. The study involved 77 physically active adults, university students (age: 19.1 ? 1.1 years; height: 170.2 ? 9.2 cm; body mass: 64.1 ? 10.7 kg). Static balance was assessed with a force platform under Romberg conditions: a foam surface, eyes open (EOFS); eyes closed (ECFS); challenging the visual-vestibular system (CVVS). The Y Balance Test (YBT) evaluated dynamic balance in anterior, posteromedial, and posterolateral directions. One-way ANOVA examined potential differences between sexes, and the Pearson product-moment test verified the correlations between YBT and static balance measures. Results. Sex differences were found for all conditions in static balance variables: ellipse area (EA), centre of pressure displacement anteroposterior (DAP) and mediolateral (DML), mean velocity anteroposterior (VAP) and mediolateral (VML), total mean velocity (TV). Females presented a better stability index than males for EOFS (25% DAP, 20% DML, 30% VAP, 21% VML, 19% TV), ECFS (26% DAP, 32% DML, 28% VAP, 32% VML, 32% TV), and CVVS (27% EA, 26% DAP, 19% DML, 17% VAP, 20% VML, 18% TV). Males demonstrated 6% better performance on YBT posterolateral. Correlation tests revealed small to moderate correlations between static and dynamic balance, except for a large positive correlation between YBT anterior and sway area under the CVVS condition [r = 0.54 (0.19; 0.77)] for women. Conclusions. The findings indicate a weak relationship between static and dynamic balance in controlling posture.D915-7373-ED16 | Cesar LeaoN/

    Macrophage Depletion in Hypertensive Rats Accelerates Development of Cardiomyopathy

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    Inflammation contributes to the process of ventricular remodeling after acute myocardial injury. To investigate the role of macrophages in the chronic process of cardiac remodeling, they were selectively depleted by intravenous administration of liposomal clodronate in heart failure-prone hypertensive Ren-2 rats from the age of 7 until 13 weeks. plain liposomes were used for comparison. Liposomal clodronate treatment reduced the number of blood monocytes and decreased the number of macrophages in the myocardium. Compared to plain liposomes, liposomal clodronate treatment rapidly worsened left ventricular ejection function in hypertensive rats. Liposomal clodronate-treated Ren-2 rat hearts showed areas of myocyte loss with abundant inflammatory cell infiltration, predominantly comprising CD4 positive T lymphocytes. The current-study showed that lack of macrophages vas associated with earlier development of myocardial dysfunction in hypertensive rats. Modulation of macrophage function may be of value in the evolution of cardiomyopath

    Nutrition status and quantification of blood minerals by TXRF spectroscopy in vegetarian and non-vegetarian university students.

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    This study investigated whether university students following a vegetarian diet differed from non-vegetarian students in nutrient intake, biochemical, hematological and blood mineral profile of nutritionally relevant elements. In total, 107 students from a university, following either a non-vegetarian or a vegetarian diet for at least 1 year prior to the study, were recruited in two stages, setting up two experiments. Nutrient intake (experiment 1, n = 58), and biochemical and hematological parameters (experiment 2, n = 49) were evaluated. TXRF spectroscopy was used for determination of trace elements in whole blood. Vegetarians showed differences in nutrient intake, mainly higher consumption of unsaturated fatty acids and fiber. No significant differences in the biochemical and hematological parameters were found. The prevalence of abnormal parameters in a considerable number of vegetarians and non-vegetarians were found, mainly regarding high density lipoprotein (HDL-c) and total cholesterol (TC). TXRF spectroscopy proved to be a simple tool for determining nutrition-relevant elements (K, Fe, Cu and Zn) in blood samples. The high incidence of abnormal parameters, regardless of the dietary pattern, raises concern about the high prevalence of bad eating habits among young university students. Particularly for the vegetarian students, these results may partly counteract the beneficial lifestyle of a vegetarian diet evidenced by previous studies. It is important for students to be aware of its potential nutritional limitations. In this context, food and nutrition education programs in the academic context could contribute to set up autonomous and healthy subjects, regardless of the diet chosen

    Effect of cooking method on the formation of 7-ketocholesterol in Atlantic hake (Merluccius hubbsi) and smooth weakfish (Cynoscion leiarchus) fillets.

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    The levels of cholesterol and 7-ketocholesterol were measured in raw Atlantic hake (Merluccius hubbsi) and smooth weakfish (Cynoscion leiarchus) fillets and in fillets subjected to the following cooking methods: baking in an electric or microwave oven; baking, grilling or stewing in a steam-convection oven; simmering on a stove; electric grilling; and deep frying. The raw samples from both fishes exhibited significantly (p < 0.05) higher cholesterol levels (62.71 ? 6.06 mg/100 ge74.16 ? 3.96 mg/ 100 g) than the processed fillets. In all of the samples, 7-ketocholesterol was detected at significantly (p < 0.05) different levels depending on the cooking method and the type of fish. Steam cooking keeping the surface of the product moist produced small decrease in the cholesterol content (26.65%e29.96%) and a low level of 7-ketocholesterol in the samples (6.90 ? 0.21 mg/ge6.47 ? 0.28 mg/g). Baking in electric or steam-convection ovens at high temperatures and long times greatly reduced the cholesterol content (52.77%e65.08%), which was associated with a large increase in 7-ketocholesterol levels (11.54 ? 0.45 mg/ge13.94 ? 1.17 mg/g). These results indicate the necessity of revising the baking procedures for fish to increase the healthiness of food

    nutrition and performance in football

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    Nutrition is an undeniable part of promoting health and performance among football (soccer) players. Nevertheless, nutritional strategies adopted in elite football can vary significantly depending on culture, habit and practical constraints and might not always be supported by scientific evidence. Therefore, a group of 28 Portuguese experts on sports nutrition, sports science and sports medicine sought to discuss current practices in the elite football landscape and review the existing evidence on nutritional strategies to be applied when supporting football players. Starting from understanding football?s physical and physiological demands, five different moments were identified: preparing to play, match-day, recovery after matches, between matches and during injury or rehabilitation periods. When applicable, specificities of nutritional support to young athletes and female players were also addressed. The result is a set of practical recommendations that gathered consensus among involved experts, highlighting carbohydrates periodisation, hydration and conscious use of dietary supplements.D915-7373-ED16 | Cesar LeaoN/

    High Migratory Survival and Highly Variable Migratory Behavior in Black-Tailed Godwits

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    Few studies have been able to directly measure the seasonal survival rates of migratory species or determine how variable the timing of migration is within individuals and across populations over multiple years. As such, it remains unclear how likely migration is to affect the population dynamics of migratory species and how capable migrants may be of responding to changing environmental conditions within their lifetimes. To address these questions, we used three types of tracking devices to track individual black-tailed godwits from the nominate subspecies (Limosa limosa limosa) throughout their annual cycles for up to 5 consecutive years. We found that godwits exhibit considerable inter- and intra-individual variation in their migratory behavior across years. We also found that godwits had generally high survival rates during migration, although survival was reduced during northward flights across the Sahara Desert. These patterns differ from those observed in most other migratory species, suggesting that migration may only be truly dangerous when crossing geographic barriers that lack emergency stopover sites and that the levels of phenotypic flexibility exhibited by some populations may enable them to rapidly respond to changing environmental conditions

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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