scholarly journals Uncoupled seasonal variability of transparent exopolymer and Coomassie stainable particles in coastal Mediterranean waters

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Marina Zamanillo ◽  
Eva Ortega-Retuerta ◽  
Carolina Cisternas-Novoa ◽  
Cèlia Marrasé ◽  
Carles Pelejero ◽  
...  
Keyword(s):  
Seasonal Variability ◽  
Environmental Variability ◽  
Temporal Dynamics ◽  
Surface Mixed Layer ◽  
Planktonic Food ◽  
Parallel Surface ◽  
Different Types ◽  
Vertical Distributions ◽  
Organic Carbon Cycling ◽  
Northwestern Mediterranean Sea

Transparent exopolymer particles (TEP) and Coomassie stainable particles (CSP) are gel-like particles, ubiquitous in the ocean, that affect important biogeochemical processes including organic carbon cycling by planktonic food webs. Despite much research on both groups of particles (especially TEP) over many years, whether they exist as distinctly stainable fractions of the same particles or as independent particles, each with different driving factors, remains unclear. To address this question, we examined the temporal dynamics of TEP and CSP over 2 complete seasonal cycles at 2 coastal sites in the Northwestern Mediterranean Sea, the Blanes Bay Microbial Observatory (BBMO) and the L’Estartit Oceanographic Station (EOS), as well as their spatial distribution along a coast-to-offshore transect. Biological, chemical, and physical variables were measured in parallel. Surface concentrations (mean ± standard deviation [SD]) of TEP were 36.7 ± 21.5 µg Xanthan Gum (XG) eq L–1 at BBMO and 36.6 ± 28.3 µg XG eq L–1 at EOS; for CSP, they were 11.9 ± 6.1 µg BSA eq L–1 at BBMO and 13.0 ± 5.9 µg BSA eq L–1 at EOS. Seasonal variability was more evident at EOS, where surface TEP and CSP concentrations peaked in summer and spring, respectively, and less predictable at the shore-most station, BBMO. Vertical distributions between surface and 80 m, monitored at EOS, showed highest TEP concentrations within the surface mixed layer during the stratification period, whereas CSP concentrations were highest before the onset of summer stratification. Phytoplankton were the main drivers of TEP and CSP distributions, although nutrient limitation and saturating irradiance also appeared to play important roles. The dynamics and distribution of TEP and CSP were uncoupled both in the coastal sites and along the transect, suggesting that they are different types of particles produced and consumed differently in response to environmental variability.

Predicting the vertical distributions of reef fish larvae in the Straits of Florida from environmental factors

2010 ◽  
Vol 67 (11) ◽  
pp. 1755-1767 ◽  
Author(s):  
Klaus B. Huebert ◽  
Su Sponaugle ◽  
Robert K. Cowen
Keyword(s):  
Coral Reef ◽  
Environmental Factors ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Fish Assemblages ◽  
Environmental Variability ◽  
Fish Larvae ◽  
Straits Of Florida ◽  
Diel Vertical Migrations ◽  
Vertical Distributions

Three seasons of vertically stratified ichthyoplankton sampling at the edge of the Florida Current revealed consistent accumulations of some coral reef fish larvae under taxon-specific environmental conditions. Environmental variability ranging from predictable (seasonal differences in temperature, diel changes in light, and vertical gradients in many variables) to stochastic (changes in wind-driven turbulence and patchiness of zooplankton) was used to model larval distributions. In five taxa, including the commercially important Epinephelini (groupers), relative larval densities were predicted with significant accuracy based entirely on sampling depth. Models yielding these predictions were cross-validated among all seasons, indicating that larval vertical distributions were remarkably unaffected by other environmental factors, while revealing strong behavioral preferences for specific ranges of hydrostatic pressure. Pomacentridae (damselfish) larvae consistently occupied shallower depths at night than during the day, demonstrating diel vertical migrations. At the community level, depth and season were two major factors structuring larval coral reef fish assemblages. Predictable vertical distributions of larvae in the Straits of Florida can facilitate modeling the same taxa elsewhere in the Western Central Atlantic.

scholarly journals Spatial and temporal prediction of fin whale distribution in the northwestern Mediterranean Sea

2008 ◽  
Vol 65 (7) ◽  
pp. 1260-1269 ◽  
Author(s):  
Sophie Laran ◽  
Alexandre Gannier
Keyword(s):  
Mediterranean Sea ◽  
Marine Protected Area ◽  
Environmental Variability ◽  
Correct Classification ◽  
Fin Whale ◽  
Chl A ◽  
Temporal Prediction ◽  
Northwestern Mediterranean Sea ◽  
Northwestern Mediterranean

Abstract Laran, S. and Gannier, A. 2008. Spatial and temporal prediction of fin whale distribution in the northwestern Mediterranean Sea. – ICES Journal of Marine Science, 65: 1260–1269. Understanding the distribution of the cetaceans is crucial to improving their conservation. Therefore, a prediction model of fin whale’s (Balaenoptera physalus) summer distribution was developed from data collected between May and August, in the Pelagos Mediterranean Marine Mammals Sanctuary. Explanatory variables were selected by multiple logistic regression, among several physiographic and oceanographic parameters. Depth, chlorophyll (Chl a) concentration, and sea surface temperature (SST) were selected for characterizing fin whale presence. Remote sensing imagery (Chl a and SST) was used at an 8-d resolution to capture short-term environmental variability. With the selection of a presence/absence threshold by the receiver operating characteristic curve, a correct classification of 70% (49% for presence, 85% for absence) was achieved for the initial dataset. Model reliability was also tested on an independent dataset, collected in the northwestern Basin; a correct classification of 71% (41% for presence prediction, 86% for absence prediction) was obtained. This study contributes to an understanding of where fin whales might concentrate to feed in summer. Weekly predictions of their distribution represent a valuable conservation tool in a marine protected area, for example to prevent collisions with ships.

Evolution, Microbes, and Changing Ocean Conditions

2020 ◽  
Vol 12 (1) ◽  
pp. 181-208 ◽  
Author(s):  
Sinéad Collins ◽  
Philip W. Boyd ◽  
Martina A. Doblin
Keyword(s):  
Experimental Evolution ◽  
Environmental Variability ◽  
Cumulative Effect ◽  
Model Systems ◽  
Environmental Drivers ◽  
Marine Microbes ◽  
Evolutionary Potential ◽  
Tolerance Limits ◽  
Different Types

Experimental evolution and the associated theory are underutilized in marine microbial studies; the two fields have developed largely in isolation. Here, we review evolutionary tools for addressing four key areas of ocean global change biology: linking plastic and evolutionary trait changes, the contribution of environmental variability to determining trait values, the role of multiple environmental drivers in trait change, and the fate of populations near their tolerance limits. Wherever possible, we highlight which data from marine studies could use evolutionary approaches and where marine model systems can advance our understanding of evolution. Finally, we discuss the emerging field of marine microbial experimental evolution. We propose a framework linking changes in environmental quality (defined as the cumulative effect on population growth rate) with population traits affecting evolutionary potential, in order to understand which evolutionary processes are likely to be most important across a range of locations for different types of marine microbes.

Arrhythmia Diagnosis through ECG Signal Classification Using A Hybrid CNN-LSTM Model: Comparison with current Deep Learning Approaches (Preprint)

2020 ◽  
Author(s):  
Nicos Maglaveras ◽  
Georgios Petmezas ◽  
Vassilis Kilintzis ◽  
Leandros Stefanopoulos ◽  
Andreas Tzavelis ◽  
...  
Keyword(s):  
Deep Learning ◽  
Cardiac Arrhythmias ◽  
Model Comparison ◽  
Temporal Dynamics ◽  
Experimental Studies ◽  
Signal Classification ◽  
Ecg Signal ◽  
Learning Approaches ◽  
Different Types

BACKGROUND Electrocardiogram (ECG) recording and interpretation is the most common method used for the diagnosis of cardiac arrhythmias, nonetheless this process requires significant expertise and effort from the doctors’ perspective. Automated ECG signal classification could be a useful technique for the accurate detection and classification of several types of arrhythmias within a short timeframe. OBJECTIVE To review current approaches using state-of-the-art CNNs and deep learning methodologies in arrhythmia detection via ECG feature classification techniques and propose an optimised architecture capable of different types of arrhythmia diagnosis using publicly existing annotated arrhythmia databases from the MIT-BIH databases available at PHYSIONET (physionet.org) . METHODS A hybrid CNN-LSTM deep learning model is proposed to classify beats derived from two large ECG databases. The approach is proposed after a systematic review of current AI/DL methods applied in different types of arrhythmia diagnosis using the same public MIT-BIH databases. In the proposed architecture the CNN part carries out feature extraction and dimensionality reduction, and the LSTM part performs classification of the encoded ECG beat signals. RESULTS In experimental studies conducted with the MIT-BIH Arrhythmia and the MIT-BIH Atrial Fibrillation Databases average accuracies of 96.82% and 96.65% were noted respectively. CONCLUSIONS The proposed system can be used for arrhythmia diagnosis in clinical and mHealth applications managing a number of prevalent arrhythmias such as VT, AFIB, LBBB etc. The capability of CNNs to reduce the ECG beat signal’s size and extract its main features can be effectively combined with the LSTMs’ capability to learn the temporal dynamics of the input data for the accurate and automatic recognition of several types of cardiac arrhythmias. CLINICALTRIAL Not applicable.

scholarly journals THE ROLE OF THE SPECIFICS OF SCHOOL INSTRUCTION IN RELATION TO MANIFESTATIONS OF SEMANTIC SENSORY ABILITIES AS MENTAL RESOURCES OF DIFFERENT TYPES OF MODALITY

2019 ◽  
Vol 1 (1) ◽  
pp. 9-16
Author(s):  
Yana Sipovkaya Ivanovna
Keyword(s):  
School Health ◽  
Temporal Dynamics ◽  
Sensory Sensitivity ◽  
Number Of Factors ◽  
Older Adolescents ◽  
Different Types ◽  
Patriotic Education ◽  
Depth Study ◽  
Degree Of Differentiation ◽  
Mental Resources

The article examines the manifestations of semantic sensory abilities of different types of modality: tactile, auditory, taste, olfactory and visual, among older teens who study at two schools with different pedagogical orientation: a school with in-depth study of foreign languages and a school "Health", emphasizing attention to the physical and patriotic education of youth. The study involved 37 ninth-graders of the senior adolescence (15 years). Methodological basis of the study was "Visual semantics". The results of the study showed that there is no difference in the degree of manifestation of sensory abilities of tactile, auditory, taste, olfactory and visual types in adolescents. It probably depends on the degree of differentiation of semantic abilities to a greater extent than from the educational environment. These results emphasize both the theoretical and practical novelty of the proposed approach in view of a number of factors. First of all, a new method for diagnosing semantic sensory abilities had been approved. Furthermore, - studying regression (Alexandrov et al., 2017) of semantic sensory abilities as a variant of mental development and adaptive application of human mental resources. Finally, - data on the absence of differences in the degree of expression of sensory semantic abilities of all types in older adolescents. The established facts increase our understanding of the most basic, low-differentiated component of the conceptual experience - semantic abilities and one of its manifestations-sensory sensations, directing factors of heterogeneity in the semantic constructions of older adolescents to research. Moreover, the study of manifestations of semantic sensory sensitivity in other age periods is of particular relevance, which will allow us to reveal the temporal dynamics of the development of this component of conceptual experience.

scholarly journals Modeling and Dynamics Analysis of a Universal Interface for Constructing Floating Fractional Order Mem-Elements

2021 ◽  
Author(s):  
Ya Li ◽  
Lijun Xie ◽  
Ciyan Zheng ◽  
Dongsheng Yu ◽  
Jason K. Eshraghian
Keyword(s):  
Fractional Order ◽  
Temporal Dynamics ◽  
Memory Systems ◽  
Memory Element ◽  
Frequency Responses ◽  
Fine Grain ◽  
Practical Design ◽  
Different Types ◽  
Universal Interface ◽  
Memory Characteristics

Abstract Fractional-order systems generalize classical differential systems and have empirically shown to achieve fine-grain modeling of the temporal dynamics and frequency responses of certain real-world phenomena. Although the study of integer-order memory element (mem-element) emulators has persisted for several years, the study of fractional-order memory elements (FOMEs) has received little attention. To promote the study of the characteristics and applications of mem-element systems in fractional calculus (FC) and memory systems, in this paper, we propose a novel universal interface for constructing floating FOMEs. When the topological structure of the interface remains unchanged, the floating fractional-order memristor (FOMR), fractional-order memcapacitor (FOMC) and fractional-order meminductor (FOMI) emulators can be realized by using the impedance combinations of different passive elements, without any mem-element emulators and mutators. When compared with previously proposed FOMEs, the proposed fractional-order mem-element emulators based on a universal interface not only feature the characteristics of floating terminals and simpler circuit structures, but can also realize all three different types of FOMEs. To explore the dynamical relationships between the mem-elements and the fractional order, we mathematically derive and analyze the maximum and minimum possible values of memductance, memcapacitance and inverse meminductance which accounts for practical design considerations when building FO systems. The memory characteristics of FOMEs are analyzed by varying their orders and stimuli frequencies. The consistency of theoretical analysis, numerical calculation and simulation results validates the correctness of our proposed emulators.

scholarly journals Environmental Variability Of The Ponto-Caspian And Mediterranean Basins During The Last Climatic Macrocycle

2020 ◽  
Vol 13 (4) ◽  
pp. 6-23
Author(s):  
Tamara A. Yanina
Keyword(s):  
Climate Change ◽  
Late Pleistocene ◽  
Global Climate Change ◽  
Environmental Variability ◽  
Global Climate ◽  
Caspian Basin ◽  
Single System ◽  
Different Types ◽  
Mediterranean Regions ◽  
Basin System

This paper reviews reconstructions of the the evolution of the Ponto-Caspian basin system to certain parts of the Pontian-Mediterranean system in order to analyze their correlation and response of the systems to the global climate change. The Ponto–Caspian and Mediterranean basins belong to different types of water basins and evolved differently in the Late Pleistocene responding in different ways to the global climate change. The paleogeographic reconstructions and correlation analysis of the Late Pleistocene events (within the last climatic macrocycle) made it possible to view the evolution of the basins as parts of a single system allowing to identify certain specific features and patterns in their functioning. The study is based on the analysis and integration of the data published by numerous researchers including the author of the paper and numerous colleagues from many countries who have been studying the paleogeography of the Ponto-Caspian and Mediterranean regions in the Late Pleistocene.

Sign in / Sign up

Export Citation Format

Share Document