Stochastic behavior of atrial and ventricular intrinsic cardiac neurons

2006 ◽  
Vol 101 (2) ◽  
pp. 413-419 ◽  
Author(s):  
M. Waldmann ◽  
G. W. Thompson ◽  
G. C. Kember ◽  
J. L. Ardell ◽  
J. A. Armour
Keyword(s):  
Nervous System ◽  
Correlation Coefficient ◽  
Cross Correlation ◽  
Mechanical Deformation ◽  
Short Term ◽  
Stochastic Behavior ◽  
Sensory Stimuli ◽  
Spatially Distributed ◽  
Tightly Coupled ◽  
Anesthetized Dogs

To quantify the concurrent transduction capabilities of spatially distributed intrinsic cardiac neurons, the activities generated by atrial vs. ventricular intrinsic cardiac neurons were recorded simultaneously in 12 anesthetized dogs at baseline and during alterations in the cardiac milieu. Few (3%) identified atrial and ventricular neurons (2 of 72 characterized neurons) responded solely to regional mechanical deformation, doing so in a tightly coupled fashion (cross-correlation coefficient r = 0.63). The remaining (97%) atrial and ventricular neurons transduced multimodal stimuli to display stochastic behavior. Specifically, ventricular chemosensory inputs modified these populations such that they generated no short-term coherence among their activities (cross-correlation coefficient r = 0.21 ± 0.07). Regional ventricular ischemia activated most atrial and ventricular neurons in a noncoupled fashion. Nicotinic activation of atrial neurons enhanced ventricular neuronal activity. Acute decentralization of the intrinsic cardiac nervous system obtunded its neuron responsiveness to cardiac sensory stimuli. Most atrial and ventricular intrinsic cardiac neurons generate concurrent stochastic activity that is predicated primarily upon their cardiac chemotransduction. As a consequence, they display relative independent short-term (beat-to-beat) control over regional cardiac indexes. Over longer time scales, their functional interdependence is manifest as the result of interganglionic interconnections and descending inputs.

scholarly journals Short-Term Radio-X-Ray Correlations of Cygnus X-1

2004 ◽  
Vol 194 ◽  
pp. 202-202
Author(s):  
T. Gleissner ◽  
J. Wihns ◽  
G. G. Pooley ◽  
M. A. Nowak ◽  
K. Pottschmidt ◽  
...  
Keyword(s):  
White Noise ◽  
Correlation Coefficient ◽  
Time Scales ◽  
Cross Correlation ◽  
Short Term ◽  
X Ray ◽  
Noise Statistics ◽  
Short Time

We analyze simultaneous radio-X-ray data of Cygnus X-l from the Ryle telescope (RT) and RXTE over more than 4 a. We show that apparent correlations on short time scales in the lightcurves of Cyg X-l are probably the coincidental outcome of white noise statistics.As a measure of correlation between radio and X-ray emission, we calculate the maximum cross-correlation coefficient, ccf, of simultaneous radio and X-ray lightcurves, which are rebinned to a resolution of 32 s and smoothed. Every single X-ray lightcurve segment is cross-correlated with the corresponding radio lightcurve, up to a maximum shift Δt = ±10 h.

scholarly journals Detrended Multiple Cross-Correlation Coefficient applied to solar radiation, air temperature and relative humidity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Solar Energy ◽  
Correlation Coefficient ◽  
Air Temperature ◽  
Cross Correlation ◽  
Global Solar Radiation ◽  
Meteorological Variables ◽  
Hourly Data ◽  
Cross Correlations

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.

scholarly journals Multiplexed neurochemical transmission emulated using a dual-excitatory synaptic transistor

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mingxue Ma ◽  
Yao Ni ◽  
Zirong Chi ◽  
Wanqing Meng ◽  
Haiyang Yu ◽  
...  
Keyword(s):  
Neural Network ◽  
Central Nervous System ◽  
Nervous System ◽  
Long Term Potentiation ◽  
Short Term ◽  
Term Potentiation ◽  
Binary Neural Network ◽  
Neuromorphic Systems ◽  
Human Brains

AbstractThe ability to emulate multiplexed neurochemical transmission is an important step toward mimicking complex brain activities. Glutamate and dopamine are neurotransmitters that regulate thinking and impulse signals independently or synergistically. However, emulation of such simultaneous neurotransmission is still challenging. Here we report design and fabrication of synaptic transistor that emulates multiplexed neurochemical transmission of glutamate and dopamine. The device can perform glutamate-induced long-term potentiation, dopamine-induced short-term potentiation, or co-release-induced depression under particular stimulus patterns. More importantly, a balanced ternary system that uses our ambipolar synaptic device backtrack input ‘true’, ‘false’ and ‘unknown’ logic signals; this process is more similar to the information processing in human brains than a traditional binary neural network. This work provides new insight for neuromorphic systems to establish new principles to reproduce the complexity of a mammalian central nervous system from simple basic units.

scholarly journals Water insecurity, illness and other factors of everyday life: A case study from Choma District, Southern Province, Zambia

Water SA ◽  
2018 ◽  
Vol 44 (4 October) ◽  
Author(s):  
Richard A Marcantonio
Keyword(s):  
Drinking Water ◽  
Everyday Life ◽  
Water Resource ◽  
Water Safety ◽  
Water Insecurity ◽  
Water Storage Capacity ◽  
Southern Province ◽  
Spatially Distributed ◽  
Tightly Coupled ◽  
Specific Outcome

Recent reports from the UN find that 2.6 billion people have gained access to improved drinking water sources since 1990, but 663 million people still live without. Other recent work demonstrates that 4 billion people annually face severe water scarcity as a result of seasonal fluctuations in water availability and quality. How is it that, despite the significant development in water resource availability documented by the UN, literally billions of people are regularly experiencing water insecurity? To begin to understand how a lack of access to reliable water resources affects everyday life, I focus on a specific outcome of water insecurity: waterborne illness. Given the difficulty in linking illness to a particular source, this research focuses on perceptions of water safety. I ask participants about illness they perceive coming from their drinking water, conducting face-to-face surveys (N = 224) spatially distributed around Choma town, Southern Province, Zambia. In particular, I investigate how these perceptions affect everyday life and what intersecting factors are likely to increase or decrease the probability of a person perceiving drinking water as the source of their illness. Our findings demonstrate that individual perceptions of waterborne illness are tightly coupled with perceptions of water needs being met or not, water flexibility (water storage capacity and water resource type and number available), total water use, food security and distance to various services. My work identifies and qualifies intersecting relationships that are critical to the design of any policy or other means of intervention intended to reduce experienced and perceived waterborne illness and other everyday needs of subsistence farmers facing the challenges presented by climate change and other forms of environmental change.

scholarly journals TAILA DHARA IN NIDRANASHA W.S.R. TO INSOMNIA

2018 ◽  
Vol 6 (06) ◽  
Author(s):  
Sumit Raosaheb Patil
Keyword(s):  
Heart Failure ◽  
Chronic Pain ◽  
Nervous System ◽  
Stable State ◽  
Low Energy ◽  
Deep Sleep ◽  
Short Term ◽  
Disturbed Sleep ◽  
The Mind

ABSTRACT Ayurveda says Nidra yuktam Sukham Dukkham, In fact, it says that sleep is one of the three pillars of health. Insomnia or Nidranasha, is not just about being not getting proper sleep but it means that the nervous system has been weakened and reduces our ability to cope up with daily sleep. Insomnia is named as Nidranasha, happens due to vitiation of Kapha, Pitta and Vata dosha. Proper and deep sleep helps the person keep Energetic, Enthusiastic, does Brumhana, increases the Bala, increases vigour and vitality and most it keeps the Mind in stable state for gaining knowledge. Insomnia means inability to get sleep at night or inability to have a restful and sound sleep. Insomnia is typically followed by daytime sleepiness, low energy, irritability, and a depressed mood. Insomnia can be short term, lasting for days or weeks, or long term, lasting more than a month. Insomnia can occur independently or as a result of another problem. Conditions that can result in insomnia include psychological stress, chronic pain, heart failure, hyperthyroidism, heartburn, Alzheimer’s disease and Parkinson’s disease, Arthritis, menopause, and certain medications, and drugs such as caffeine, nicotine, and alcohol. Treatment of Insomnia:- Panchakarma â€“ Taila dhara a type of Shirodhara is very much useful in combacting the Insomnia caused due to various above said disorders. So its a demand of time to know about the real sleep and the disturbed sleep according to Ayurveda and Mordern medicines also and effect of Taila Dhara Brahmi,Jatamamsi siddha) in treating Insomnia.

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