scholarly journals MeLa: A Programming Language for a New Multidisciplinary Oceanographic Float

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6081
Author(s):  
Sébastien Bonnieux ◽  
Dorian Cazau ◽  
Sébastien Mosser ◽  
Mireille Blay-Fornarino ◽  
Yann Hello ◽  
...  
Keyword(s):  
Programming Language ◽  
Embedded Software ◽  
Detection Algorithm ◽  
Global Scale ◽  
P Wave ◽  
Anthropogenic Activity ◽  
Acoustic Data ◽  
Signal Processing Algorithms ◽  
Blue Whales ◽  
Argo Project

At 2000 m depth in the oceans, one can hear biological, seismological, meteorological, and anthropogenic activity. Acoustic monitoring of the oceans at a global scale and over long periods of time could bring important information for various sciences. The Argo project monitors the physical properties of the oceans with autonomous floats, some of which are also equipped with a hydrophone. These have a limited transmission bandwidth requiring acoustic data to be processed on board. However, developing signal processing algorithms for these instruments requires one to be an expert in embedded software. To reduce the need of such expertise, we have developed a programming language, called MeLa. The language hides several aspects of embedded software with specialized programming concepts. It uses models to compute energy consumption, processor usage, and data transmission costs early during the development of applications; this helps to choose a strategy of data processing that has a minimum impact on performances. Simulations on a computer allow for verifying the performance of the algorithms before their deployment on the instrument. We have implemented a seismic P wave detection and a blue whales D call detection algorithm with the MeLa language to show its capabilities. These are the first efforts toward multidisciplinary monitoring of the oceans, which can extend beyond acoustic applications.

Abstract P505: Real-world Data Validation Of A Novel P-wave Based Automatic Atrial Fibrillation Detection Algorithm

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Åke Olsson ◽  
Magnus Samulesson
Keyword(s):  
Real World ◽  
False Negative ◽  
Detection Algorithm ◽  
P Wave ◽  
Detection Accuracy ◽  
The Novel ◽  
Real World Data ◽  
P Waves ◽  
World Data ◽  
Rr Variability

Background: Automatic ECG algorithms using only RR-variability in ECG to detect AF have shown high false positive rates. By including P-wave presence in the algorithm, research has shown that it can increase detection accuracy for AF. Methods: A novel RR- and P-wave based automatic detection algorithm implemented in the Coala Heart Monitor ("Coala", Coala Life AB, Sweden) was evaluated for detection accuracy by the comparison to blinded manual ECG interpretation based on real-world data. Evaluation was conducted on 100 consecutive anonymous printouts of chest- and thumb-ECG waveforms, where the algorithm had detected both irregular RR-rhythms and strong P-waves in either chest or thumb recording (non-AF episodes classified by algorithm as Category 12).The recordings, without exclusions, were generated from 5,512 real-world data recordings from actual Coala users in Sweden (both OTC and Rx users) during the period of March 5 to March 22, 2019, with no control or influence by the researchers or any other organization or individual. The prevalence of cardiac conditions in the user population was unknown.The blinded recordings were each manually interpreted by a trained cardiologist. The manual interpretation was compared with the automatic analysis performed by the detection algorithm to determine the number of additional false negative indications for AF as presented to the user. Results: The trained cardiologist manually interpreted 0 of the 100 recordings as AF. Manual interpretation showed that the novel automatic AF algorithm yielded 0 % False Negative error and 100 % Negative Predictive Value (NPV) for detection of AF. Irregular RR-rhythms were detected in 569 recordings (10 % of a total of 5,512 recordings). The 100 non-AF recordings containing both irregular RR-rhythms and strong P-waves constituted 18% of all recordings with irregular RR-rhythms. Respiratory sinus arrhythmia was the single most prevalent condition and was found in 47% of irregular RR-rhythms with strong P-waves. Conclusion: The novel, P-wave based automatic ECG algorithm used in the Coala, showed a zero percent False Negative error rate for AF detection in ECG recordings with RR-variability but presence of P-waves, as compared to manual interpretation by a cardiologist.

scholarly journals Opportunistically recorded acoustic data support Northeast Atlantic mackerel expansion theory

2015 ◽  
Vol 73 (4) ◽  
pp. 1115-1126 ◽  
Author(s):  
Jeroen van der Kooij ◽  
Sascha M.M. Fässler ◽  
David Stephens ◽  
Lisa Readdy ◽  
Beth E. Scott ◽  
...  
Keyword(s):  
North Sea ◽  
Stock Assessment ◽  
Detection Algorithm ◽  
Trawl Survey ◽  
Northeast Atlantic ◽  
Acoustic Data ◽  
The North ◽  
The North Sea ◽  
Northern North Sea ◽  
Feeding Grounds

Abstract Fisheries independent monitoring of widely distributed pelagic fish species which conduct large seasonal migrations is logistically complex and expensive. One of the commercially most important examples of such a species in the Northeast Atlantic Ocean is mackerel for which up to recently only an international triennial egg survey contributed to the stock assessment. In this study, we explore whether fisheries acoustic data, recorded opportunistically during the English component of the North Sea International Bottom Trawl Survey, can contribute to an improved understanding of mackerel distribution and provide supplementary data to existing dedicated monitoring surveys. Using a previously published multifrequency acoustic mackerel detection algorithm, we extracted the distribution and abundance of schooling mackerel for the whole of the North Sea during August and September between 2007 and 2013. The spatio-temporal coverage of this unique dataset is of particular interest because it includes part of the unsurveyed summer mackerel feeding grounds in the northern North Sea. Recent increases in landings in Icelandic waters during this season suggested that changes have occurred in the mackerel feeding distribution. Thus far it is poorly understood whether these changes are due to a shift, i.e. mackerel moving away from their traditional feeding grounds in the northern North Sea and southern Norwegian Sea, or whether the species' distribution has expanded. We therefore explored whether acoustically derived biomass of schooling mackerel declined in the northern North Sea during the study period, which would suggest a shift in mackerel distribution rather than an expansion. The results of this study show that in the North Sea, schooling mackerel abundance has increased and that its distribution in this area has not changed over this period. Both of these findings provide, to our knowledge, the first evidence in support of the hypothesis that mackerel have expanded their distribution rather than moved away.

scholarly journals Characterizing the Spatial Patterns of Global Fertilizer Application and Manure Production

2010 ◽  
Vol 14 (2) ◽  
pp. 1-22 ◽  
Author(s):  
Philip Potter ◽  
Navin Ramankutty ◽  
Elena M. Bennett ◽  
Simon D. Donner
Keyword(s):  
Soil Nutrients ◽  
Spatial Patterns ◽  
National Level ◽  
Nutrient Content ◽  
Global Scale ◽  
Anthropogenic Activity ◽  
Spatially Explicit ◽  
Nutrient Runoff ◽  
Fertilizer Use ◽  
The Impact

Abstract Agriculture has had a tremendous impact on soil nutrients around the world. In some regions, soil nutrients are depleted because of low initial soil fertility or excessive nutrient removals through intense land use relative to nutrient additions. In other regions, application of chemical fertilizers and manure has led to an accumulation of nutrients and subsequent water quality problems. Understanding the current level and spatial patterns of fertilizer and manure inputs would greatly improve the ability to identify areas that might be sensitive to aquatic eutrophication or to nutrient depletion. The authors calculated spatially explicit fertilizer inputs of nitrogen (N) and phosphorus (P) by fusing national-level statistics on fertilizer use with global maps of harvested area for 175 crops. They also calculated spatially explicit manure inputs of N and P by fusing global maps of animal density and international data on manure production and nutrient content. Significantly higher application rates were found for both fertilizers and manures in the Northern Hemisphere, with maxima centered on areas with intensive cropland and high densities of livestock. Furthermore, nutrient use is confined to a few major hot spots, with approximately 10% of the treated land receiving over 50% of the use of both fertilizers and manures. The authors’ new spatial disaggregation of the rich International Fertilizer Industry Association (IFA) fertilizer-use dataset will provide new and interesting avenues to explore the impact of anthropogenic activity on ecosystems at the global scale and may also have implications for policies designed to improve soil quality or reduce nutrient runoff.

A New Method to Detect P-Wave Based on Quadratic Function

2011 ◽  
Vol 267 ◽  
pp. 462-467
Author(s):  
Nan Quan Zhou
Keyword(s):  
Quadratic Function ◽  
Least Square Method ◽  
Detection Algorithm ◽  
Least Square ◽  
P Wave ◽  
Good Effect ◽  
Rate Variation ◽  
Optimal Interval ◽  
Wave Detection ◽  
Wide Range

The paper presents a P-wave detection algorithm based on fitting function in the optimal interval. In the algorithm we used quadratic function to fit the P wave by this means of least square method in every interval, which was shifted in local range. Then we found the optimal fitting interval of P wave by comparing the error of fitting. Finally, we obtained the characteristic points of P wave by using the fitting function to fit P wave in the optimal interval. The performance of the algorithm tested using the records of the MIT-BIH database was effective and accurate. The algorithm on the wide range of heart rate variation and small P wave of ECG P-wave detection has good effect. Also it has some capabilities of anti-interference, particularly the false dismissal probability is quite low.

scholarly journals Evaluation of Percutaneous Coronary Intervention for Acute ST-Segment Elevation Myocardial Infarction with Hypertension by Dynamic Electrocardiogram Feature Data

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
Guoqiang Wang ◽  
Yu Wang ◽  
Ru Zhao
Keyword(s):  
Myocardial Infarction ◽  
Percutaneous Coronary Intervention ◽  
Coronary Intervention ◽  
Detection Algorithm ◽  
P Wave ◽  
St Segment Elevation ◽  
Segment Elevation Myocardial Infarction ◽  
Wave Detection ◽  
St Segment ◽  
Percutaneous Coronary

This work was to study the application value of dynamic electrocardiogram (ECG) feature data in evaluating the curative effect of percutaneous coronary intervention in acute ST-segment elevation myocardial infarction with hypertension, so as to facilitate the early diagnosis and treatment of the disease. In this study, 90 patients with acute ST-segment elevation myocardial infarction accompanied by hypertension were selected as the study subjects and randomly divided into group A (oral aspirin antiplatelet therapy), group B (thrombolytic drug streptokinase (SK) therapy), and group C (percutaneous coronary intervention), with 30 cases in each group. In addition, a P-wave detection algorithm was introduced for automatic detection and analysis of electrocardiograms, and the efficacy of patients was assessed by Holter feature data based on the P-wave detection algorithm. The results showed that the diagnostic error rate, sensitivity, and predictive accuracy of the P-wave detection algorithm for ST-segment elevation myocardial infarction caused by acute occlusion of left main coronary artery (LMCA) were 0.24%, 95.41%, and 92.33%, respectively; the diagnostic error rate, sensitivity, and predictive accuracy for non-LMCA (nLMCA) ST-segment elevation myocardial infarction were 0.28%, 95.32%, and 96.07%, respectively; the proportion of patients with symptom to blood flow patency time <3 h in group C (55.3%) was significantly higher than that in groups A and B (22.1% and 22.6%) ( P  < 0.05). Compared with group A, the content of B-type natriuretic peptide (pre-proBNP) at 1 week, 2 weeks, and 3 weeks after treatment in groups B and C was significantly lower and group C was significantly lower than group B ( P  < 0.05). In summary, the P-wave detection algorithm has a high application value in the diagnosis and early prediction of acute ST-segment elevation myocardial infarction. Percutaneous coronary intervention in the treatment of acute ST-segment elevation myocardial infarction with hypertension can shorten the opening time of infarction blood flow, so as to effectively protect the heart function of patients.

scholarly journals GOME-2 observations of oxygenated VOCs: what can we learn from the ratio glyoxal to formaldehyde on a global scale?

2010 ◽  
Vol 10 (8) ◽  
pp. 19031-19069 ◽  
Author(s):  
M. Vrekoussis ◽  
F. Wittrock ◽  
A. Richter ◽  
J. P. Burrows
Keyword(s):  
Vegetation Index ◽  
Lower Troposphere ◽  
Global Scale ◽  
Photochemical Activity ◽  
Biogenic Emissions ◽  
Anthropogenic Activity ◽  
Anthropogenic Emissions ◽  
Data Sets ◽  
Large Cities ◽  
First Time

Abstract. Collocated data sets of glyoxal (CHO.CHO) and formaldehyde (HCHO) were retrieved for the first time from measurements of the Global Ozone Monitoring Experiment-2 (GOME-2 during the first two years of operation in 2007 and 2008. Both oxygenated Volatile Organic Compounds, OVOC are key intermediate species produced during the oxidation of precursor hydrocarbons. Their short lifetime of a few hours in the lower troposphere links them to emission sources and makes them useful tracers of photochemical activity. The global composite maps of GOME-2 HCHO and CHO.CHO have strong similarities confirming their common atmospheric and/or surface sources. The highest column amounts of these OVOCs are recorded over regions with enhance biogenic emissions (e.g. tropical forests) in South America, Africa and Indonesia). Enhanced OVOC values are also present over areas of anthropogenic activity and biomass burning (e.g. over China, N. America, Europe and Australia). The ratio of CHO.CHO to HCHO, RGF, has been used, for the first time on a global scale, to classify the sources according to biogenic and/or anthropogenic emissions of the precursors; RGF between 0.040 to 0.060 point to the existence of biogenic emissions with the highest values being observed at the highest Enhanced Vegetation Index, EVI. RGFs below 0.040 are indicative of anthropogenic emissions and associated with high levels of NO2. This decreasing tendency of RGF with increasing NO2 is also observed when analyzing data for individual large cities, indicating that it is a common feature. The results obtained for RGF from GOME-2 data are compared with the findings based on regional SCIAMACHY observations showing good agreement. This is explained by the excellent correlation of the global retrieved column amounts of CHO.CHO and HCHO from the GOME-2 and SCIAMACHY instruments for the period 2007–2008.

scholarly journals Seasonal Occurrence of Sympatric Blue Whale Subspecies: the Chilean and Southeast Indian Ocean Pygmy Blue Whales With the Antarctic Blue Whale

2021 ◽  
Vol 8 ◽  
Author(s):  
Gary Truong ◽  
Tracey L. Rogers
Keyword(s):  
Indian Ocean ◽  
Southern Hemisphere ◽  
Lower Latitude ◽  
Seasonal Patterns ◽  
Austral Winter ◽  
Blue Whale ◽  
Acoustic Data ◽  
The Pacific ◽  
The Antarctic ◽  
Blue Whales

There are multiple blue whale acoustic populations found across the Southern Hemisphere. The different subspecies of blue whales feed in separate areas, but during their migration to lower-latitude breeding areas each year, Antarctic blue whales become sympatric with pygmy and Chilean blue whales. Few studies have compared the degree of this overlap of the Southern Hemisphere blue whale subspecies across ocean basins during their migration. Using up to 16 years of acoustic data, this study compares the broad seasonal presence of Antarctic blue whales, Chilean blue whales, and Southeast Indian Ocean (SEIO) pygmy blue whales across the Pacific and Indian Oceans. Antarctic blue whales were sympatric with the other two blue whale subspecies during the migrating season of every year. Despite this overlap, Chilean and pygmy blue whale detections peaked earlier during the austral autumn (April–May) while Antarctic blue whale detections peaked later during the austral winter (June). Chilean (Pacific Ocean) and SEIO (Indian Ocean) pygmy blue whales showed similar seasonal patterns in detections despite occurring in different ocean basins. Though we have shown that Antarctic blue whales have the potential to encounter other blue whale subspecies during the breeding season, these distinct groups have remained acoustically stable through time. Further understanding of where these whales migrate will enable a better insight as to how these subspecies continue to remain separate.

scholarly journals Characterizing flow in the first hundred-meter depth of a fractured aquifer using hybrid seismic methods, acoustic logging, and flow-log measurements

2021 ◽  
Vol 76 ◽  
pp. 62
Author(s):  
Jean-Luc Mari ◽  
Frederick Delay ◽  
Gilles Porel ◽  
Pierre Gaudiani
Keyword(s):  
Wave Velocity ◽  
Field Experiments ◽  
Seismic Profile ◽  
P Wave ◽  
Fractured Aquifer ◽  
Acoustic Logging ◽  
Acoustic Data ◽  
Reflection Seismic ◽  
Seismic Methods ◽  
P Wave Velocity

Understanding subsurface flow, especially in fractured rocks only housing water through a few preferential pathways, is still challenging. The point is mainly associated with the poor accessibility of the subsurface and the lack of accurate representations for both heterogeneity and spatial distribution of water bearing bodies. This notwithstanding, highly-resolved geophysical investigations bring new images of the subsurface. This is exemplified over a fractured limestone aquifer at the site scale (for example, that of the radius of influence of an extraction well). On an experimental site, situated in the Cher region (France), two boreholes have been drilled for field experiments. Full Waveform Acoustic Logging (FWAL) and seismic experiments were conducted. Hybrid seismic imaging, which consists in combining refraction and reflection seismic results, has been carried out. Based on a four-step procedure, the processing of refracted and reflected waves provided two sections. After assemblage, these sections produced in a first step an extended time reflectivity section starting from the surface and, in a second step, a section over depth after calibration with Vertical Seismic Profile (VSP) and acoustic data. However, even the Very High Resolution (VHR) seismic methods do not have a sufficient vertical resolution to describe accurately the geological formation. The acoustic sections were processed to separate the different wave fields, to extract the criss-cross events and to build a criss-cross index log. A log of fracturation index, based on both criss-cross index and P-wave velocity measurements, was computed to detect the presence of fractures. After calibration, and under the assumption that the slower the P-wave velocity, the higher the permeability – porosity, a 3D seismic block of reflection can inform on preferential areas where flow should occur. At the scale of an open wellbore, acoustic loggings that measure wave velocities over a short distance within the well also inform on open features crosscut by the well. Finally, flow log measurements confirm the occurrence of flowing horizons that were previously marked by both seismic and acoustic data. Seismic and acoustic data are therefore suited to image contrasted hydraulic properties over fractured subsurface systems usually poorly documented.

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