34 research outputs found

    Experimental study on RSS based indoor positioning algorithms

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    This work compares the performance of indoor positioning systems suitable for low power wireless sensor networks. The research goal is to study positioning techniques that are compatible with real-time positioning in wireless sensor networks, having low-power and low complexity as requirements. Map matching, approximate positioning (weighted centroid) and exact positioning algorithms (least squares) were tested and compared in a small predefined indoor environment. We found that, for our test scenario, weighted centroid algorithms provide better results than map matching. Least squares proved to be completely unreliable when using distances obtained by the one-slope propagation model. Major improvements in the positioning error were found when body influence was removed from the test scenario. The results show that the positioning error can be improved if the body effect in received signal strength is accounted for in the algorithms.Helder D. Silva is supported by the Portuguese Foundation for Science and Technology under the grant SFRBD/78018/2011.info:eu-repo/semantics/publishedVersio

    Body attenuation and path loss exponent estimation for RSS-based positioning in WSN

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    The influence of the human body in antenna systems has significant impact in the received signal strength (RSS) of wireless transmissions. Accounting for body effect is generally considered as being able to improve position estimation based on RSS measurements. In this work we perform several experiments with a wireless sensor network, using a sensor node equipped with an inertial measurement unit (IMU), in order to obtain the relative orientation between the sensor node and multiple anchor nodes. A model of the RSS attenuation induced by the body was created using experimental measurements in a controlled environment and applied to a real-time positioning system. A path loss exponent (PLE) estimation method using RSS information from neighbor anchors was also implemented and evaluated. Weighted centroid localization (WCL) algorithm was the positioning method used in this work. When the sensor node was placed on the user’s body, accounting for body effect produced negligible improvements (6%) in the best-case scenario and consistently degraded accuracy under real conditions, whether the node was placed on the user’s body (in the order of 3%), 10 cm away (from 14% to 35%) or 20 cm away from the body (from 42% to 105%) for results in the 70th percentile. The PLE estimation method showed improvements (in the order of 11%) when the sensor node is further away from the body. Results demonstrate that the distance between sensor node and the body has an extremely important influence on the accuracy of the position estimate.This work has been supported by FCT (Fundação para a Ciência e Tecnologia) in the scope of the project UID/EEA/04436/2013. Helder D. Silva is supported by FCT under the grant SFRH/BD/78018/2011info:eu-repo/semantics/publishedVersio

    Hipertiroidismo por Secreção Inapropriada Não Tumoral de TSH

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    Apresenta-se um caso clínico de hipertiroidismo por secreção inapropriada não tumoral de TSH, numa mulher de 31 anos, investigado na sequência do achado de T3 e TSH elevados após tiroidecto mia. A resposta exagerada de TSH à TRH e a supressão parcial após triiodotironina aliadas à normal expressão morfológica tomodensitométrica da região selar confirmaram o diagnóstico. As terapêuticas com bromocriptina e ocjreotido revelaram-se ineficazes na supressa da TSH. O ensaio com 3-5-3’ ácido triiodotiroacético ficou deferido pela ocorrência de gravidez e aleitamento

    Myxedema Coma

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    Os AA. apresentam 5 casos de coma mixedematoso observados no período de 1984 a 1992. Trata-se de 4 doentes do sexo feminino e 1 do sexo masculino com idades compreendidas entre os 45 e 73 anos. Em 3 doentes não havia diagnóstico prévio de hipotiroidismo. A depressão do estado de consciência, a hipotermia, a bradicardia e a ausência de bócio eram comuns aos 5 doentes. Foi identificado factor desencadeante em 3 deles. Utilizada levotiroxina e/ou liotironina por via oral, hidrocortisona e medidas de suporte, a evolução foi favorável nos 2 doentes em que tinha sido identificado factor desencadeante, que apresentavam menor depressão do S.N.C. e normalização da temperatura corporal ao 3° dia de terapêutica

    Myxedema Coma

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    Os AA. apresentam 5 casos de coma mixedematoso observados no período de 1984 a 1992. Trata-se de 4 doentes do sexo feminino e 1 do sexo masculino com idades compreendidas entre os 45 e 73 anos. Em 3 doentes não havia diagnóstico prévio de hipotiroidismo. A depressão do estado de consciência, a hipotermia, a bradicardia e a ausência de bócio eram comuns aos 5 doentes. Foi identificado factor desencadeante em 3 deles. Utilizada levotiroxina e/ou liotironina por via oral, hidrocortisona e medidas de suporte, a evolução foi favorável nos 2 doentes em que tinha sido identificado factor desencadeante, que apresentavam menor depressão do S.N.C. e normalização da temperatura corporal ao 3° dia de terapêutica

    Influence of cover cropping on water uptake dynamics in an irrigated Mediterranean vineyard

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    As a result of its physiological characteristics, vine's yield and quality responses are greatly affected by water availability in the soil. Knowledge about water uptake of grapevines in high water availability pedoclimatic conditions is essential when considering the increasing use of irrigation in a previously rainfed crop. We studied the water uptake of irrigated grapevines under different soil covers. The study was carried out over two years in southern Portugal, a Mediterranean climate region, in 'Aragonez' grapevines installed in Vertisols. A cover crop was sown in half the area while maintaining the permanent resident vegetation in the remaining area. Five levels of annual irrigation supply were applied: 200 mm; 150 mm; 100 mm; 50 mm; no irrigation. Soil moisture was monitored every two or three weeks, and weekly after the irrigation start. Results show that water uptake in the interrows did not cease after the beginning of irrigation. Water uptake by the vines occurred to depths of approximately 3.00 m, hence 7.5 times greater than the cover crop root system depth. Results suggest that over time, the presence of the cover crop forces the vine root system, mainly its thinner roots, to seek water at increasingly deeper soil compartments

    An innervated skin 3D in vitro model for dermatological research

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    A 3D in vitro model of innervated skin would be a useful tool in dermatological research to study the effect of different chemicals and compounds on the sensory properties of skin. Current innervated skin models are limited in composition and often composed of ex vivo skin explants and/or animal-derived material. In this study, our aim was to develop a human innervated skin model with a better biomimicry composition for in vitro research. Fibrin hydrogel and aligned electrospun fibers of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) were used as a scaffold to generate the 3D in vitro model. The skin component was made of primary human keratinocytes and primary human fibroblasts, while the neuronal component was composed of iPSC-derived sensory neurons. Our results showed that the dermal component consisted of fibroblasts and synthesized collagen. The epidermal component was characterized by the expression of keratins 10 and 14, and involucrin. Finally, sensory neurons extended axons throughout the scaffold and reached the epidermis. Treating the model with a capsaicin solution for 30 min, which was performed as a proof of concept test for sensitization studies, resulted into partial depletion of substance P and tubulin β3. This model could be used for studying skin-neuron interactions and cutaneous toxicity.</p

    Complete blood count parameters as biomarkers of retinopathy of prematurity: a Portuguese multicenter study

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    © The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Purpose: To evaluate complete blood count (CBC) parameters in the first week of life as predictive biomarkers for the development of retinopathy of prematurity (ROP). Methods: Multicenter, prospective, observational study of a cohort of preterm infants born with gestational age (GA) < 32 weeks or birth weight < 1500 g in eight Portuguese neonatal intensive care units. All demographic, clinical, and laboratory data from the first week of life were collected. Univariate logistic regression was used to assess risk factors for ROP and then multivariate regression was performed. Results: A total of 455 infants were included in the study. The median GA was 29.6 weeks, and the median birth weight was 1295 g. One hundred and seventy-two infants (37.8%) developed ROP. Median values of erythrocytes (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), lymphocytes (p = 0.035), and platelets (p = 0.003) of the group of infants diagnosed with ROP any stage were lower than those without ROP. Mean corpuscular volume (MCV) (p = 0.044), red blood cell distribution width (RDW) (p < 0.001), erythroblasts (p < 0.001), neutrophils (p = 0.030), neutrophils-lymphocytes ratio (p = 0.028), and basophils (p = 0.003) were higher in the ROP group. Higher values of MCV, erythroblasts, and basophils remained significantly associated with ROP after multivariate regression. Conclusion: In our cohort, the increase in erythroblasts, MCV, and basophils in the first week of life was significantly and independently associated with the development of ROP. These CBC parameters may be early predictive biomarkers for ROP.Open access funding provided by FCT|FCCN (b-on). This work was supported by the Laboratório de Genética and the Instituto de Saúde Ambiental (ISAMB) of the Faculdade de Medicina of Universidade de Lisboa and the Instituto de Investigação Científica Bento da Rocha Cabral. The writing of the manuscript was also supported by funds from Fundação para a Ciência e a Tecnologia to ISAMB (ref. UIDB/04295/2020 and UIDP/04295/2020). This work was also part of a doctoral project funding by the company CUF with a PhD grant in Medicine awarded in 2021 and by the Portuguese Society of Ophthalmology with a PhD grant awarded in 2019.info:eu-repo/semantics/publishedVersio

    Complete blood count parameters as biomarkers of retinopathy of prematurity: a Portuguese multicenter study

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    Purpose: To evaluate complete blood count (CBC) parameters in the first week of life as predictive biomarkers for the development of retinopathy of prematurity (ROP). Methods: Multicenter, prospective, observational study of a cohort of preterm infants born with gestational age (GA) < 32 weeks or birth weight < 1500 g in eight Portuguese neonatal intensive care units. All demographic, clinical, and laboratory data from the first week of life were collected. Univariate logistic regression was used to assess risk factors for ROP and then multivariate regression was performed. Results: A total of 455 infants were included in the study. The median GA was 29.6 weeks, and the median birth weight was 1295 g. One hundred and seventy-two infants (37.8%) developed ROP. Median values of erythrocytes (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), lymphocytes (p = 0.035), and platelets (p = 0.003) of the group of infants diagnosed with ROP any stage were lower than those without ROP. Mean corpuscular volume (MCV) (p = 0.044), red blood cell distribution width (RDW) (p < 0.001), erythroblasts (p < 0.001), neutrophils (p = 0.030), neutrophils-lymphocytes ratio (p = 0.028), and basophils (p = 0.003) were higher in the ROP group. Higher values of MCV, erythroblasts, and basophils remained significantly associated with ROP after multivariate regression. Conclusion: In our cohort, the increase in erythroblasts, MCV, and basophils in the first week of life was significantly and independently associated with the development of ROP. These CBC parameters may be early predictive biomarkers for ROP.info:eu-repo/semantics/publishedVersio
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