128 research outputs found
Application of Sentinel-1 satellite to identify oil palm plantations in Balikpapan Bay
Satellite remote sensing has proved to be efficient for monitoring of canopy changes. In tropical areas, optical or multispectral satellite images are very often negatively affected by cloud cover, on the other hand satellites with polarimetric radars have a great advantage given their ability to penetrate clouds, smoke and atmospheric haze. Copernicus Sentinel-1 radar constellation offers both vertically co-polarized and cross-polarized imagery in a relatively high revisit time and resolution. This work describes an approach to identify selected palm oil plantations in Balikpapan Bay, East Kalimantan (Borneo). It gives an overview about advantages for monitoring temporal changes in the tropic environment using radar imagery but also constraints due to ambiguity of canopy type identification. The paper shows a brief comparison with application of multispectral Copernicus Sentinel-2 data and points a roadmap towards a practical application of the technologies
Experimental Feasibility Study of Estimation of the Normalized Central Blood Pressure Waveform from Radial Photoplethysmogram
Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk
Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-layer perceptron (MLP) neural networks, radial basis function (RBF) neural networks and support vector machines (SVM) for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%). Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis
Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk
Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-layer perceptron (MLP) neural networks, radial basis function (RBF) neural networks and support vector machines (SVM) for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%). Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis
Sympathetic Activation and Baroreflex Function during Intradialytic Hypertensive Episodes
BACKGROUND: The mechanisms of intradialytic increases in blood pressure are not well defined. The present study was undertaken to assess the role of autonomic nervous system activation during intradialytic hypertensive episodes. METHODOLOGY/PRINCIPAL FINDINGS: Continuous interbeat intervals (IBI) and systolic blood pressure (SBP) were monitored during hemodialysis in 108 chronic patients. Intradialytic hypertensive episodes defined as a period of at least 10 mmHg increase in SBP between the beginning and the end of a dialysis session or hypertension resistant to ultrafiltration occurring during or immediately after the dialysis procedure, were detected in 62 out of 113 hemodialysis sessions. SBP variability, IBI variability and baroreceptor sensitivity (BRS) in the low (LF) and high (HF) frequency ranges were assessed using the complex demodulation technique (CDM). Intradialytic hypertensive episodes were associated with an increased (nâ=â45) or decreased (nâ=â17) heart rate. The maximal blood pressure was similar in both groups. In patients with increased heart rate the increase in blood pressure was associated with marked increases in SBP and IBI variability, with suppressed BRS indices and enhanced sympatho-vagal balance. In contrast, in those with decreased heart rate, there were no significant changes in the above parameters. End-of-dialysis blood pressure in all sessions associated with hypertensive episode was significantly higher than in those without such episodes. In logistic regression analysis, predialysis BRS in the low frequency range was found to be the main predictor of intradialytic hypertension. CONCLUSION/SIGNIFICANCE: Our data point to sympathetic overactivity with feed-forward blood pressure enhancement as an important mechanism of intradialytic hypertension in a significant proportion of patients. The triggers of increased sympathetic activity during hemodialysis remain to be determined. Intradialytic hypertensive episodes are associated with higher end-of-dialysis blood pressure, suggesting that intradialytic hypertension may play a role in generation of interdialytic hypertension
British randomised controlled trial of AV and VV optimization ("BRAVO") study:rationale, design, and endpoints
Background Echocardiographic optimization of pacemaker settings is the current standard of care for patients treated with cardiac resynchronization therapy. However, the process requires considerable time of expert staff. The BRAVO study is a non-inferiority trial comparing echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay with an alternative method using non-invasive blood pressure monitoring that can be automated to consume less staff resources. Methods/Design BRAVO is a multi-centre, randomized, cross-over, non-inferiority trial of 400 patients with a previously implanted cardiac resynchronization device. Patients are randomly allocated to six months in each arm. In the echocardiographic arm, AV delay is optimized using the iterative method and VV delay by maximizing LVOT VTI. In the haemodynamic arm AV and VV delay are optimized using non-invasive blood pressure measured using finger photoplethysmography. At the end of each six month arm, patients undergo the primary outcome measure of objective exercise capacity, quantified as peak oxygen uptake (VO2) on a cardiopulmonary exercise test. Secondary outcome measures are echocardiographic measurement of left ventricular remodelling, quality of life score and N-terminal pro B-type Natriuretic Peptide (NT-pro BNP). The study is scheduled to complete recruitment in December 2013 and to complete follow up in December 2014. Discussion If exercise capacity is non-inferior with haemodynamic optimization compared with echocardiographic optimization, it would be proof of concept that haemodynamic optimization is an acceptable alternative which has the potential to be more easily implemented
Effect of two commercial preparations containing different GnRH analogues with dopamine antagonists on barbel Barbus barbus (L.) sperm quantity and quality
The drift of early life stages of Percidae and Gobiidae (Pisces: Teleostei) in a free-flowing section of the Austrian Danube
Ocena osiadaĹ powierzchni terenu rejonu ostrawsko-karwiĹskiego naruszonego dziaĹalnoĹciÄ gĂłrniczÄ w odniesieniu do stref geologiczno-inĹźynierskich
The study deals with the evaluation of terrain subsidence (isocatabases) as one of the most important manifestations of mining exploitation. Development of human activities in various spheres of interest occurs also in such affected landscapes. In terms of the engineering geology there is a need for subsidence development assessment in time in relation to the engineering-geological zones representing the geological environment with similar characteristics. It's very essential for the foundation engineering. Overlay analyses in the Geographic Information Systems of the stated factors bring the necessary information for land-use decision-making and planning. The case study in the selected part of the Karvina section of the Ostrava-Karvina District (map sheet 15-44-02) was implemented in the cadastral district of the town of Orlova in the north-east of the Czech Republic.W artykule przyjÄto temat oceny osiadaĹ terenu, jednego z najistotniejszych objawĂłw eksploatacji gĂłrniczej. RozwĂłj dziaĹalnoĹci czĹowieka przejawia siÄ ogĂłlnym naruszeniem krajobrazu. Dla wymagaĹ geologii inĹźynierskiej zachodzi potrzeba oceny rozwoju niecki osiadaĹ w czasie dla odpowiednich stref geologiczno-inĹźynierskich opisujÄ
cy Ĺrodowisko geologiczne o podobnych cechach. Jest to niezbÄdne dla tematyki fundamentowania. Przetworzenie danych z analiz inĹźynierskich przez Geograficzny System Informatyczny (GIS) daje niezbÄdne informacje dla decyzji dotyczÄ
cych zagospodarowania przestrzennego. Jako analizÄ przypadku wybrano miasto Orloga, znajdujÄ
ce siÄ w rejonie Karwiny-ZagĹÄbia Ostrawsko-KarwiĹskiego (karta mapy nr 15-44-02)
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