167 research outputs found

    ТНЕ INFLUENCE Of CORТICAL FACТORS ON NEURO-VEGETAТIVE REACТIVIТY

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    The ргоblеm of interrelations between the cervical cortex and its higher vegetative centers has an essential bеагiпg on the complex process of influencing and regulating functions in the organisrn. Recently it has assumed а particular actuality, brought about bу the гapid progress of our knowledge on the physiological importance ol formatio reticularis in which higher vegetative centers аге included. With the pur pose of studying some particular aspects in this interrelation, we in­vestigated the changes in the neuro-vegetative reactivity during examination sessions of students; as well known, in them а widespread radiation occurs of excitation processes produced bу the examination state. The influence of the functional conditions of the сегеbгаl согtех on some of the vegetative functions during examination of students was also subject to investigation bу Gotzev and associates

    ТНЕ EFFECT OF VARNA SEA-COAST CLIMAТIC FACTORS ON NEURO-VEGEТAТIVE REACТIVIТY

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    The effect of Black sea-coast factors оn various functions of healthy individuals and persons with various affections has been the objective of а number оf investigations in Bulgaria. The alterations of the neuro-vegetative reactivity under the effect of climatic factors of the sea-shore region is of special interest, for it greatly contributes to the elucidatjon оf the mechanism bу which these factors influence and mnodify the various functions оf the organism

    Achieving good environmental status in the Black Sea: scale mismatches in environmental management

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    The Black Sea has suffered severe environmental degradation. Governance of the Black Sea region is complex and results in a series of scale mismatches which constrain management. This paper develops a simple classification of spatial scale mismatches incorporating the driver, pressure, state, welfare, response (DPSWR) framework. The scale mismatch classification is applied to two major environmental problems of the Black Sea, eutrophication and small pelagic fisheries. A number of scale mismatches are described and classified and potential solutions are identified

    Seasonal differences in fatty acid content of white brine cheese offered at the Bulgarian market

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    The present study provides scientific information for fatty acid composition of white brine cheese from cow milk, produced from all regions of Bulgaria, across seasons for the period 2012–2016. A total of 670 samples produced from different manufacturers and collected from supermarkets by Offi-cial control of Bulgarian Food Safety Agency (BFSA) were examined. Fatty acid composition was determined by gas chromatography. The milk fat purity of 18 samples was established through gas chromatographic analysis of triglycerides. Seasonal variations were observed in fatty acid composi-tion of white brine cheese. The seasonal changes in the concentration of lauric, myristic, palmitic, stearic, oleic and α-linolenic acids have largely contributed to the variation of fatty acid composition of cheese. Saturated fatty acids (SFAs) were in the range 68.39–71.53% of total FAs and the propor-tion of unsaturated fatty acids (UFA) was 28.44–31.61% of total FAs. Fourty-five out of examined samples have exhibited different fatty acid profile than that established in the present study for cow milk cheese. The determined SFAs were 44.7–57.5% and UFA varied from 42.5% to 55.3%. The fatty acids with short chain (C4:0 ÷ C10:0) were not detected or in traces, lauric and myristic acids were in small amounts, while palmitic and oleic acids predominated in the fatty acid composition of cheese analogues

    Removal of power-line interference from the ECG: a review of the subtraction procedure

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    BACKGROUND: Modern biomedical amplifiers have a very high common mode rejection ratio. Nevertheless, recordings are often contaminated by residual power-line interference. Traditional analogue and digital filters are known to suppress ECG components near to the power-line frequency. Different types of digital notch filters are widely used despite their inherent contradiction: tolerable signal distortion needs a narrow frequency band, which leads to ineffective filtering in cases of larger frequency deviation of the interference. Adaptive filtering introduces unacceptable transient response time, especially after steep and large QRS complexes. Other available techniques such as Fourier transform do not work in real time. The subtraction procedure is found to cope better with this problem. METHOD: The subtraction procedure was developed some two decades ago, and almost totally eliminates power-line interference from the ECG signal. This procedure does not affect the signal frequency components around the interfering frequency. Digital filtering is applied on linear segments of the signal to remove the interference components. These interference components are stored and further subtracted from the signal wherever non-linear segments are encountered. RESULTS: Modifications of the subtraction procedure have been used in thousands of ECG instruments and computer-aided systems. Other work has extended this procedure to almost all possible cases of sampling rate and interference frequency variation. Improved structure of the on-line procedure has worked successfully regardless of the multiplicity between the sampling rate and the interference frequency. Such flexibility is due to the use of specific filter modules. CONCLUSION: The subtraction procedure has largely proved advantageous over other methods for power-line interference cancellation in ECG signals

    Effect of Contour Shape of Nervous System Electromagnetic Stimulation Coils on the Induced Electrical Field Distribution

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    BACKGROUND: Electromagnetic stimulation of the nervous system has the advantage of reduced discomfort in activating nerves. For brain structures stimulation, it has become a clinically accepted modality. Coil designs usually consider factors such as optimization of induced power, focussing, field shape etc. In this study we are attempting to find the effect of the coil contour shape on the electrical field distribution for magnetic stimulation. METHOD AND RESULTS: We use the maximum of the induced electric field stimulation in the region of interest as the optimization criterion. This choice required the application of the calculus of variation, with the contour perimeter taken as a pre-set condition. Four types of coils are studied and compared: circular, square, triangular and an 'optimally' shaped contour. The latter yields higher values of the induced electrical field in depths up to about 30 mm, but for depths around 100 mm, the circular shape has a slight advantage. The validity of the model results was checked by experimental measurements in a tank with saline solution, where differences of about 12% were found. In view the accuracy limitations of the computational and measurement methods used, such differences are considered acceptable. CONCLUSION: We applied an optimization approach, using the calculus of variation, which allows to obtain a coil contour shape corresponding to a selected criterion. In this case, the optimal contour showed higher intensities for a longer line along the depth-axis. The method allows modifying the induced field structure and focussing the field to a selected zone or line

    Dataset of manually measured QT intervals in the electrocardiogram

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    BACKGROUND: The QT interval and the QT dispersion are currently a subject of considerable interest. Cardiac repolarization delay is known to favor the development of arrhythmias. The QT dispersion, defined as the difference between the longest and the shortest QT intervals or as the standard deviation of the QT duration in the 12-lead ECG is assumed to be reliable predictor of cardiovascular mortality. The seventh annual PhysioNet/Computers in Cardiology Challenge, 2006 addresses a question of high clinical interest: Can the QT interval be measured by fully automated methods with accuracy acceptable for clinical evaluations? METHOD: The PTB Diagnostic ECG Database was given to 4 cardiologists and 1 biomedical engineer for manual marking of QRS onsets and T-wave ends in 458 recordings. Each recording consisted of one selected beat in lead II, chosen visually to have minimum baseline shift, noise, and artifact. In cases where no T wave could be observed or its amplitude was very small, the referees were instructed to mark a 'group-T-wave end' taking into consideration leads with better manifested T wave. A modified Delphi approach was used, which included up to three rounds of measurements to obtain results closer to the median. RESULTS: A total amount of 2*5*548 Q-onsets and T-wave ends were manually marked during round 1. To obtain closer to the median results, 8.58 % of Q-onsets and 3.21 % of the T-wave ends had to be reviewed during round 2, and 1.50 % Q-onsets and 1.17 % T-wave ends in round 3. The mean and standard deviation of the differences between the values of the referees and the median after round 3 were 2.43 ± 0.96 ms for the Q-onset, and 7.43 ± 3.44 ms for the T-wave end. CONCLUSION: A fully accessible, on the Internet, dataset of manually measured Q-onsets and T-wave ends was created and presented in additional file: 1 (Table 4) with this article. Thus, an available standard can be used for the development of automated methods for the detection of Q-onsets, T-wave ends and for QT interval measurements

    Scientific, Technical and Economic Committee for Fisheries (STECF) : 64th Plenary Report (PLEN-20-02)

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    The Scientific, Technical and Economic Committee for Fisheries (STECF) held its 64th plenary as a virtual meeting from 6-10 July 2020.-- 128 pagesCommission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar discipline

    Ten lessons on the resilience of the EU common fisheries policy towards climate change and fuel efficiency - A call for adaptive, flexible and well-informed fisheries management

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    To effectively future-proof the management of the European Union fishing fleets we have explored a suite of case studies encompassing the northeast and tropical Atlantic, the Mediterranean, Baltic and Black Seas. This study shows that European Union (EU) fisheries are likely resilient to climate-driven short-term stresses, but may be negatively impacted by long-term trends in climate change. However, fisheries' long-term stock resilience can be improved (and therefore be more resilient to increasing changes in climate) by adopting robust and adaptive fisheries management, provided such measures are based on sound scientific advice which includes uncertainty. Such management requires regular updates of biological reference points. Such updates will delineate safe biological limits for exploitation, providing both high long-term yields with reduced risk of stock collapse when affected by short-term stresses, and enhanced compliance with advice to avoid higher than intended fishing mortality. However, high resilience of the exploited ecosystem does not necessarily lead to the resilience of the economy of EU fisheries from suffering shocks associated with reduced yields, neither to a reduced carbon footprint if fuel use increases from lower stock abundances. Fuel consumption is impacted by stock development, but also by changes in vessel and gear technologies, as well as fishing techniques. In this respect, energy-efficient fishing technologies already exist within the EU, though implementing them would require improving the uptake of innovations and demonstrating to stakeholders the potential for both reduced fuel costs and increased catch rates. A transition towards reducing fuel consumption and costs would need to be supported by the setup of EU regulatory instruments. Overall, to effectively manage EU fisheries within a changing climate, flexible, adaptive, well-informed and well-enforced management is needed, with incentives provided for innovations and ocean literacy to cope with the changing conditions, while also reducing the dependency of the capture fishing industry on fossil fuels. To support such management, we provide 10 lessons to characterize 'win-win' fishing strategies for the European Union, which develop leverages in which fishing effort deployed corresponds to Maximum Sustainable Yield targets and Common Fisheries Policy minimal effects objectives. In these strategies, higher catch is obtained in the long run, less fuel is spent to attain the catch, and the fisheries have a higher resistance and resilience to shock and long-term factors to face climate-induced stresses
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