73 research outputs found
Towards an accurate sleep apnea detection based on ECG signal: The quintessential of a wise feature selection
A wise feature selection from minute-to-minute Electrocardiogram (ECG) signal is a challenging task for
many reasons, but mostly because of the promise of the accurate detection of clinical disorders, such as
the sleep apnea. In this study, the ECG signal was modeled in order to obtain the Heart Rate Variability
(HRV) and the ECG-Derived Respiration (EDR). Selected features techniques were used for benchmark
with different classifiers such as Artificial Neural Networks (ANN) and Support Vector Machine(SVM),
among others. The results evidence that the best accuracy was 82.12%, with a sensitivity and specificity
of 88.41% and 72.29%, respectively. In addition, experiments revealed that a wise feature selection
may improve the system accuracy. Therefore, the proposed model revealed to be reliable and simpler
alternative to classical solutions for the sleep apnea detection, for example the ones based on the
Polysomnography.info:eu-repo/semantics/publishedVersio
Urinary Protein Excretion Profile: A Contribution For Subclinical Renal Damage Identification Among Environmental Heavy Metals Exposure In Southeast Brazil
In Southeast Brazil. Ribeira Valley region has been a major public health concern due to the environmental heavy metals contamination indexes of vegetation, rocks and aquifers, caused by local mining in the past. Human contamination by low levels of heavy metals doesn't cause acute intoxication but in chronic exposure, renal damage may occur with progressive tubulointerstitial changes evolving to glomerular lesion. In this study we investigated the relationship between the profile of urinary excreted proteins (glomerular or tubular origin) of arsenic and mercury and blood lead concentration in children and adults from highly exposed regions of the Ribeira Valley. The subjects were classified as GROUP 1 (G1; higher environmental risk, n=333) and GROUP 2 (G2; lower risk of contamination, n=104). In order to determine the urinary excretion of total protein, albumin (MA, glomerular marker) and alpha I microglobulin (A1M, tubular marker) and the blood lead concentrations, random urine and blood samples were obtained. Plasmatic lead levels were assessed by atomic absorption spectrometry with graphite furnace. Total protein concentration (PROT) was assessed on a biochemical analyzer (pyrogallol red method). MA and A1M were determined by nephelometric method. Group 1 showed a higher frequency of altered urinary excretion of PROT (G1=3.4%; G2=1.0%), MA (G1=9.0%; G2=5.1%) and A1M (G1=7.5%; G2=3.8%), without significant differences between both groups. Elevated arsenic levels were more prevalent among subjects from Group 1 (28.8%) and demonstrated a significant correlation with abnormal urinary excretion of albumin and alpha-1-microglobulin (p=0.019). Lead and mercury levels showed no difference among the groups and no correlation with MA and/or A1M. Our data suggests that abnormal urinary protein excretion is relatively frequent in this population independently of the plasmatic or urinary heavy metal levels. The early detection of possible renal damage become necessary for effective measures can be taken to prevent clinical nephropathies.107I513516Eysink, G.G.J., Avaliação da qualidade ambiental do Rio Ribeira do Iguape- ConsideraçÔes preliminares, relatório técnico da CETESB (1991), p. 54. , CETESB, São PauloPaoliello, M.M.B., De Capitani, E.M., Cunha, F.G., Matsuo, T., Carvalho, M.F., Sakuma, A., Figueiredo, B.R., Exposure of children to lead and cadmium from a mining area of Brazil (2002) Environmental Research, 88, pp. 120-128Bennet, B.G., Exposure of man to environmental arsenic - an exposure commitment assessment (1981) Sci Total Environ, 20 (2), pp. 99-107Hewitt, D.J., Millner, G.C., Nye, A.C., Simmons, H.F., Investigation of arsenic exposure from soil at a superfund site (1995) Environ. Research, 68, pp. 73-81Goyer, R.A., Mechanisms of lead and cadmium nephrotoxicity (1989) Toxicol Lett., 46, pp. 153-162Chia, K.S., Jeyaratnam, J., Lee, J., Tan, C., Ong, H.Y., Ong, C.N., Lee, E., Lead-induced nephropathy: Relationship between various biological exposure indices and early markers of nephrotoxicity (1995) Am J Ind Med, 27 (6), pp. 883-895Kim, R., Rotnitsky, A., Sparrow, D., Weiss, S., Wager, C., Hu, H., A longitudinal study of low level lead exposure and impairment of renal function. The normative aging study (1996) JAMA, 275, pp. 1177-1181Cardenas, A., Roels, H., Bernard, A.M., Markers of early renal changes induced by industrial pollutants. II. Application to workers exposed to lead (1993) Br J Ind Med, 50, pp. 28-36Kusano, E., Suzuki, M., Asano, Y., Takagi, K., Tadashi, K., Human alfa-1-microglobulin and its relationship to renal function (1985) Nephron, 41, pp. 320-324Pergande, M., Jung, K., Precht, S., Fels, L.M., Herbort, C., Stolte, H., Changed excretion of urinary proteins and enzymes by chronic exposure to lead (1994) Nephrol Dial Transplant, 9 (6), pp. 613-618Preventing lead poisoning in young children: A statement by the centers for disease control (1991), Centers for Disease Control and Prevention-USDHHS- PHS, Washington, octoberPaschal, D.C., Trace metals in urine of United States residentes: Reference range concentrations (1998) Environ Research, 76, pp. 53-59not
Combining inhomogeneous magnetization transfer and multipoint Dixon acquisition: potential utility and evaluation
Purpose The recently introduced inhomogeneous magnetization transfer (ihMT) method has predominantly been applied for imaging the central nervous system. Future applications of ihMT, such as in peripheral nerves and muscles, will involve imaging in the vicinity of adipose tissues. This work aims to systematically investigate the partial volume effect of fat on the ihMT signal and to propose an efficient fat-separation method that does not interfere with ihMT measurements.Methods First, the influence of fat on ihMT signal was studied using simulations. Next, the ihMT sequence was combined with a multi-echo Dixon acquisition for fat separation. The sequence was tested in 9 healthy volunteers using a 3T human scanner. The ihMT ratio (ihMTR) values were calculated in regions of interest in the brain and the spinal cord using standard acquisition (no fat saturation), water-only, in-phase, and out-of-phase reconstructions. The values obtained were compared with a standard fat suppression method, spectral presaturation with inversion recovery.Results Simulations showed variations in the ihMTR values in the presence of fat, depending on the TEs used. The IhMTR values in the brain and spinal cord derived from the water-only ihMT multi-echo Dixon images were in good agreement with values from the unsuppressed sequence. The ihMT-spectral presaturation with inversion recovery combination resulted in 24%-35% lower ihMTR values compared with the standard non-fat-suppressed acquisition.Conclusion The presence of fat within a voxel affects the ihMTR calculations. The IhMT multi-echo Dixon method does not compromise the observable ihMT effect and can potentially be used to remove fat influence in ihMT.Neuro Imaging Researc
Magmatismo cĂĄlcio-alcalino Calimiano no embasamento do Terreno Jauru (ProvĂncia Rondoniana - San IgnĂĄcio), CrĂĄton AmazĂŽnico: geoquĂmica e geocronologia Sm-Nd E U/Pb
Effect of allopurinol in addition to hypothermia treatment in neonates for hypoxic-ischemic brain injury on neurocognitive outcome (ALBINO): Study protocol of a blinded randomized placebo-controlled parallel group multicenter trial for superiority (phase III)
Background: Perinatal asphyxia and resulting hypoxic-ischemic encephalopathy is a major cause of death and long-term disability in term born neonates. Up to 20,000 infants each year are affected by HIE in Europe and even more in regions with lower level of perinatal care. The only established therapy to improve outcome in these infants is therapeutic hypothermia. Allopurinol is a xanthine oxidase inhibitor that reduces the production of oxygen radicals as superoxide, which contributes to secondary energy failure and apoptosis in neurons and glial cells after reperfusion of hypoxic brain tissue and may further improve outcome if administered in addition to therapeutic hypothermia. Methods: This study on the effects of ALlopurinol in addition to hypothermia treatment for hypoxic-ischemic Brain Injury on Neurocognitive Outcome (ALBINO), is a European double-blinded randomized placebo-controlled parallel group multicenter trial (Phase III) to evaluate the effect of postnatal allopurinol administered in addition to standard of care (including therapeutic hypothermia if indicated) on the incidence of death and severe neurodevelopmental impairment at 24 months of age in newborns with perinatal hypoxic-ischemic insult and signs of potentially evolving encephalopathy. Allopurinol or placebo will be given in addition to therapeutic hypothermia (where indicated) to infants with a gestational age 65 36 weeks and a birth weight 65 2500 g, with severe perinatal asphyxia and potentially evolving encephalopathy. The primary endpoint of this study will be death or severe neurodevelopmental impairment versus survival without severe neurodevelopmental impairment at the age of two years. Effects on brain injury by magnetic resonance imaging and cerebral ultrasound, electric brain activity, concentrations of peroxidation products and S100B, will also be studied along with effects on heart function and pharmacokinetics of allopurinol after iv-infusion. Discussion: This trial will provide data to assess the efficacy and safety of early postnatal allopurinol in term infants with evolving hypoxic-ischemic encephalopathy. If proven efficacious and safe, allopurinol could become part of a neuroprotective pharmacological treatment strategy in addition to therapeutic hypothermia in children with perinatal asphyxia. Trial registration: NCT03162653, www.ClinicalTrials.gov, May 22, 2017
Isolamento e seleção de fungos produtores de lipases com base na atividade lipĂĄsica e no potencial hidrolĂtico sobre Ăłleo comestĂvel de soja e escuma de caixa de gordura
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans â anteaters, sloths, and armadillos â have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
TRY plant trait database â enhanced coverage and open access
Plant traitsâthe morphological, anatomical, physiological, biochemical and phenological characteristics of plantsâdetermine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traitsâalmost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
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