905 resultados para Erythrocyte Indices


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This study examines the performance of series of two geomagnetic indices and series synthesized from a semi-empirical model of magnetospheric currents, in explaining the geomagnetic activity observed at Northern Hemipshere's mid-latitude ground-based stations. We analyse data, for the 2007 to 2014 period, from four magnetic observatories (Coimbra, Portugal; Panagyurishte, Bulgary; Novosibirsk, Russia and Boulder, USA), at geomagnetic latitudes between 40° and 50° N. The quiet daily (QD) variation is firstly removed from the time series of the geomagnetic horizontal component (H) using natural orthogonal components (NOC) tools. We compare the resulting series with series of storm-time disturbance (Dst) and ring current (RC) indices and with H series synthesized from the Tsyganenko and Sitnov (2005, doi:10.1029/2004JA010798) (TS05) semi-empirical model of storm-time geomagnetic field. In the analysis, we separate days with low and high local K-index values. Our results show that NOC models are as efficient as standard models of QD variation in preparing raw data to be compared with proxies, but with much less complexity. For the two stations in Europe, we obtain indication that NOC models could be able to separate ionospheric and magnetospheric contributions. Dst and RC series explain the four observatory H-series successfully, with values for the mean of significant correlation coefficients, from 0.5 to 0.6 during low geomagnetic activity (K less than 4) and from 0.6 to 0.7 for geomagnetic active days (K greater than or equal to 4). With regard to the performance of TS05, our results show that the four observatories separate into two groups: Coimbra and Panagyurishte, in one group, for which the magnetospheric/ionospheric ratio in QD variation is smaller, a dominantly QD ionospheric contribution can be removed and TS05 simulations are the best proxy; Boulder and Novosibirsk,in the other group, for which the ionospheric and magnetospheric contributions in QD variation can not be differentiated and correlations with TS05 series can not be made to improve. The main contributor to magnetospheric QD signal are Birkeland currents. The relatively good success of TS05 model in explaining ground-based irregular geomagnetic activity at mid-latitudes makes it an effective tool to classify storms according to their main sources. For Coimbra and Panagyurishte in particular, where ionospheric and magnetospheric daily contributions seem easier to separate, we can aspire to use the TS05 model for ensemble generation in space weather (SW) forecasting and interpretation of past SW events.

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Automatic detection of blood components is an important topic in the field of hematology. The segmentation is an important stage because it allows components to be grouped into common areas and processed separately and leukocyte differential classification enables them to be analyzed separately. With the auto-segmentation and differential classification, this work is contributing to the analysis process of blood components by providing tools that reduce the manual labor and increasing its accuracy and efficiency. Using techniques of digital image processing associated with a generic and automatic fuzzy approach, this work proposes two Fuzzy Inference Systems, defined as I and II, for autosegmentation of blood components and leukocyte differential classification, respectively, in microscopic images smears. Using the Fuzzy Inference System I, the proposed technique performs the segmentation of the image in four regions: the leukocyte’s nucleus and cytoplasm, erythrocyte and plasma area and using the Fuzzy Inference System II and the segmented leukocyte (nucleus and cytoplasm) classify them differentially in five types: basophils, eosinophils, lymphocytes, monocytes and neutrophils. Were used for testing 530 images containing microscopic samples of blood smears with different methods. The images were processed and its accuracy indices and Gold Standards were calculated and compared with the manual results and other results found at literature for the same problems. Regarding segmentation, a technique developed showed percentages of accuracy of 97.31% for leukocytes, 95.39% to erythrocytes and 95.06% for blood plasma. As for the differential classification, the percentage varied between 92.98% and 98.39% for the different leukocyte types. In addition to promoting auto-segmentation and differential classification, the proposed technique also contributes to the definition of new descriptors and the construction of an image database using various processes hematological staining

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Deep-water coral ecosystems are hot spots of biodiversity and provide habitats and refuges for several deep-sea species. However, their role in shaping the biodiversity of the surrounding open slopes is still poorly known. We investigated how meiofaunal biodiversity varies with and is related to the occurrence of deep-water living scleractinian corals and coral rubble in two deep-sea areas (the Rockall Bank, northeastern Atlantic) and the Santa Maria di Leuca (central Mediterranean). In both areas, replicated sampling on alive and dead coral areas and from the adjacent slope sediments without corals (at the same and increasing depths) allowed us to demonstrate that sediments surrounding the living corals and coral rubble were characterised by higher meiofaunal biodiversity (as number of higher taxa, and nematode species richness) than the slope sediments. Despite the soft sediments surrounding the living coral having a higher nutritional value than those not associated with corals, with the opposite seen for coral rubble, the presence of both alive and dead corals had a significant effect on nematode assemblages. Our data suggest that, due particularly to the effects on habitat heterogeneity/complexity, both living coral and coral rubble promoted higher biodiversity levels than in surrounding slope sediments. We conclude that the protection of deep-water corals can be crucial to preserve the biodiversity of surrounding open slopes, and that the protection of dead corals, a so-far almost neglected habitat in terms of biological conservation, can further contribute to the maintenance of a high deep-sea biodiversity along continental margins.

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CHAPTER II - This study evaluated the effects of two different types of acute aerobic exercise on the osmotic stability of human erythrocyte membrane and on different hematological and biochemical variables that are associated with this membrane property. The study population consisted of 20 healthy and active men. Participants performed single sessions of two types of exercise. The first session consisted of 60 min of moderate-intensity continuous exercise (MICE). The second session, executed a week later, consisted of high-intensity interval exercise (HIIE) until exhaustion. The osmotic stability of the erythrocyte membrane was represented by the inverse of the salt concentration (1/H50) at the midpoint of the sigmoidal curve of dependence between the absorbance of hemoglobin and the NaCl concentration. The values of 1/H50 changed from 2.29 ± 0.1 to 2.33 ± 0.09 after MICE and from 2.30 ± 0.08 to 2.23 ± 0.12 after HIIE. In MICE has occurred an increase in the mean corpuscular volume, probably due to in vivo lysis of older erythrocytes, with preservation of cells that were larger and more resistant to in vitro lysis. The study showed that a single bout of acute exercise affected the erythrocyte osmotic stability, which increased after MICE and decreased after HIIE.

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Date of Acceptance: 02/03/2015