scholarly journals A Theoretical Analysis of Relations between Pressure Changes along Xylem Vessels and Propagation of Variation Potential in Higher Plants

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 372
Author(s):  
Ekaterina Sukhova ◽  
Elena Akinchits ◽  
Sergey V. Gudkov ◽  
Roman Y. Pishchalnikov ◽  
Vladimir Vodeneev ◽  
...  
Keyword(s):  
Higher Plants ◽  
Initial Point ◽  
Electrical Signal ◽  
Terminal Point ◽  
Hydraulic Pressure ◽  
Long Distance ◽  
Variation Potential ◽  
Damaged Zone ◽  
Pressure Dynamics ◽  
The Impact

Variation potential (VP) is an important long-distance electrical signal in higher plants that is induced by local damages, influences numerous physiological processes, and participates in plant adaptation to stressors. The transmission of increased hydraulic pressure through xylem vessels is the probable mechanism of VP propagation in plants; however, the rates of the pressure transmission and VP propagation can strongly vary. We analyzed this problem on the basis of a simple mathematical model of the pressure distribution along a xylem vessel, which was approximated by a tube with a pressure gradient. It is assumed that the VP is initiated if the integral over pressure is more than a threshold one, taking into account that the pressure is transiently increased in the initial point of the tube and is kept constant in the terminal point. It was shown that this simple model can well describe the parameters of VP propagation in higher plants, including the increase in time before VP initiation and the decrease in the rate of VP propagation with an increase in the distance from the zone of damage. Considering three types of the pressure dynamics, our model predicts that the velocity of VP propagation can be stimulated by an increase in the length of a plant shoot and also depends on pressure dynamics in the damaged zone. Our results theoretically support the hypothesis about the impact of pressure variations in xylem vessels on VP propagation.

scholarly journals Electrical Signaling of Plants under Abiotic Stressors: Transmission of Stimulus-Specific Information

2021 ◽  
Vol 22 (19) ◽  
pp. 10715
Author(s):  
Maxim Mudrilov ◽  
Maria Ladeynova ◽  
Marina Grinberg ◽  
Irina Balalaeva ◽  
Vladimir Vodeneev
Keyword(s):  
Abiotic Factors ◽  
Electrical Signal ◽  
Specific Information ◽  
Systemic Response ◽  
Long Distance ◽  
Variation Potential ◽  
Electrical Signals ◽  
Physiological Processes ◽  
Abiotic Stressors ◽  
Electrical Signaling

Plants have developed complex systems of perception and signaling to adapt to changing environmental conditions. Electrical signaling is one of the most promising candidates for the regulatory mechanisms of the systemic functional response under the local action of various stimuli. Long-distance electrical signals of plants, such as action potential (AP), variation potential (VP), and systemic potential (SP), show specificities to types of inducing stimuli. The systemic response induced by a long-distance electrical signal, representing a change in the activity of a complex of molecular-physiological processes, includes a nonspecific component and a stimulus-specific component. This review discusses possible mechanisms for transmitting information about the nature of the stimulus and the formation of a specific systemic response with the participation of electrical signals induced by various abiotic factors.

scholarly journals Inactivation of H+-ATPase Participates in the Influence of Variation Potential on Photosynthesis and Respiration in Peas

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1585
Author(s):  
Lyubov Yudina ◽  
Oksana Sherstneva ◽  
Ekaterina Sukhova ◽  
Marina Grinberg ◽  
Sergey Mysyagin ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Higher Plants ◽  
Pulse Amplitude ◽  
Electrical Signal ◽  
Sodium Orthovanadate ◽  
Variation Potential ◽  
Pam Fluorometer ◽  
Pea Seedlings ◽  
Photosynthesis And Respiration ◽  
Respiratory Responses

Local damage (e.g., burning, heating, or crushing) causes the generation and propagation of a variation potential (VP), which is a unique electrical signal in higher plants. A VP influences numerous physiological processes, with photosynthesis and respiration being important targets. VP generation is based on transient inactivation of H+-ATPase in plasma membrane. In this work, we investigated the participation of this inactivation in the development of VP-induced photosynthetic and respiratory responses. Two- to three-week-old pea seedlings (Pisum sativum L.) and their protoplasts were investigated. Photosynthesis and respiration in intact seedlings were measured using a GFS-3000 gas analyzer, Dual-PAM-100 Pulse-Amplitude-Modulation (PAM)-fluorometer, and a Dual-PAM gas-exchange Cuvette 3010-Dual. Electrical activity was measured using extracellular electrodes. The parameters of photosynthetic light reactions in protoplasts were measured using the Dual-PAM-100; photosynthesis- and respiration-related changes in O2 exchange rate were measured using an Oxygraph Plus System. We found that preliminary changes in the activity of H+-ATPase in the plasma membrane (its inactivation by sodium orthovanadate or activation by fusicoccin) influenced the amplitudes and magnitudes of VP-induced photosynthetic and respiratory responses in intact seedlings. Decreases in H+-ATPase activity (sodium orthovanadate treatment) induced fast decreases in photosynthetic activity and increases in respiration in protoplasts. Thus, our results support the effect of H+-ATPase inactivation on VP-induced photosynthetic and respiratory responses.

The methodological approach for the determination of the pressure of artificial raindrops as a question of the theory of splash soil erosion

2020 ◽  
pp. 24-28
Author(s):  
Mihail Zver'kov
Keyword(s):  
Block Diagram ◽  
Methodological Approach ◽  
Control Measures ◽  
Soil Conditions ◽  
Effective Pressure ◽  
Long Distance ◽  
Splash Erosion ◽  
Rain Drops ◽  
Artificial Rain ◽  
The Impact

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.

DISCRESSION OF THE SAMPLE RESORTS POLICE IN THE IMPLEMENTATION OF ADMINISTRATIVE LAW PERSPECTIVE INVESTIGATION

2020 ◽  
Vol 4 (2) ◽  
pp. 147
Author(s):  
Tamrin Muchsin ◽  
Sri Sudono Saliro ◽  
Nahot Tua Parlindungan Sihaloho ◽  
Sardjana Orba Manullang
Keyword(s):  
Empirical Research ◽  
Qualitative Method ◽  
Government Regulation ◽  
Sampling Technique ◽  
Administrative Law ◽  
Criminal Investigation ◽  
Accurate Data ◽  
Long Distance ◽  
The Impact ◽  
Depth Interviews

It is still found that investigating officers do not have an S1 degree or equivalent in thejurisdiction of the Sambass Resort Police as mandated in PP No. 58 of 2010 concerningAmendments to Government Regulation Number 27 of 1983 concerning theImplementation of KUHAP article 2A paragraph (1) letter a. If the requirements ofinvestigators are not fulfilled, there will automatically be limits of authority, includingthe inability to issue investigation orders, detention warrants and other administrativeletters. This study used a qualitative method with juridical empirical research. Toobtain accurate data, purposive sampling technique was used, and primary datacollection by conducting in-depth interviews. The research results found, among others:first, discretion regarding the administration of investigations in the jurisdiction of theSambas Resort Police for the Sambas District Police who do not have investigatingofficers who meet the requirements, is then taken over by the Head of the CriminalInvestigation Unit as the supervisor of the integrated criminal investigation function.Second, the impact of an integrated investigation administration causes the time tocarry out investigations to be slow due to the long distance between the Sector Policeand the Resort Police.

45. Education at distance: Broadcasting ECG rounds to Southeastern Ontario (BESO Project). An innovative approach for teaching electrocardiography

2007 ◽  
Vol 30 (4) ◽  
pp. 51 ◽  
Author(s):  
A. Baranchuk ◽  
G. Dagnone ◽  
P. Fowler ◽  
M. N. Harrison ◽  
L. Lisnevskaia ◽  
...  
Keyword(s):  
Health Care ◽  
Real Time ◽  
Digital Signal ◽  
Teaching Methodology ◽  
Care Providers ◽  
Long Distance ◽  
Medicine Clerkship ◽  
Time Problem ◽  
The Impact ◽  
Ecg Interpretation

Electrocardiography (ECG) interpretation is an essential skill for physicians as well as for many other health care professionals. Continuing education is necessary to maintain these skills. The process of teaching and learning ECG interpretation is complex and involves both deductive mechanisms and recognition of patterns for different clinical situations (“pattern recognition”). The successful methodologies of interactive sessions and real time problem based learning have never been evaluated with a long distance education model. To evaluate the efficacy of broadcasting ECG rounds to different hospitals in the Southeastern Ontario region; to perform qualitative research to determine the impact of this methodology in developing and maintaining skills in ECG interpretation. ECG rounds are held weekly at Kingston General Hospital and will be transmitted live to Napanee, Belleville, Oshawa, Peterborough and Brockville. The teaching methodology is based on real ECG cases. The audience is invited to analyze the ECG case and the coordinator will introduce comments to guide the case through the proper algorithm. Final interpretation will be achieved emphasizing the deductive process and the relevance of each case. An evaluation will be filled out by each participant at the end of each session. Videoconferencing works through a vast array of internet LANs, WANs, ISDN phone lines, routers, switches, firewalls and Codecs (Coder/Decoder) and bridges. A videoconference Codec takes the analog audio and video signal codes and compresses it into a digital signal and transmits that digital signal to another Codec where the signal is decompressed and retranslated back into analog video and audio. This compression and decompression allows large amounts of data to be transferred across a network at close to real time (384 kbps with 30 frames of video per second). Videoconferencing communication works on voice activation so whichever site is speaking has the floor and is seen by all the participating sites. A continuous presence mode allows each site to have the same visual and audio involvement as the host site. A bridged multipoint can connect between 8 and 12 sites simultaneously. This innovative methodology for teaching ECG will facilitate access to developing and maintaining skills in ECG interpretation for a large number of health care providers. Bertsch TF, Callas PW, Rubin A. Effectiveness of lectures attended via interactive video conferencing versus in-person in preparing third-year internal medicine clerkship students for clinical practice examinations. Teach Learn Med 2007; 19(1):4-8. Yellowlees PM, Hogarth M, Hilty DM. The importance of distributed broadband networks to academic biomedical research and education programs. Acad Psychaitry 2006;30:451-455

scholarly journals The Effect of LiDAR Sampling Density on DTM Accuracy for Areas with Heavy Forest Cover

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 265
Author(s):  
Mihnea Cățeanu ◽  
Arcadie Ciubotaru
Keyword(s):  
Forest Cover ◽  
Initial Point ◽  
Ground Surface ◽  
Digital Terrain Model ◽  
Morphological Data ◽  
Sampling Density ◽  
Terrain Model ◽  
Digital Terrain ◽  
Point Density ◽  
The Impact

Laser scanning via LiDAR is a powerful technique for collecting data necessary for Digital Terrain Model (DTM) generation, even in densely forested areas. LiDAR observations located at the ground level can be separated from the initial point cloud and used as input for the generation of a Digital Terrain Model (DTM) via interpolation. This paper proposes a quantitative analysis of the accuracy of DTMs (and derived slope maps) obtained from LiDAR data and is focused on conditions common to most forestry activities (rough, steep terrain with forest cover). Three interpolation algorithms were tested: Inverse Distance Weighted (IDW), Natural Neighbour (NN) and Thin-Plate Spline (TPS). Research was mainly focused on the issue of point data density. To analyze its impact on the quality of ground surface modelling, the density of the filtered data set was artificially lowered (from 0.89 to 0.09 points/m2) by randomly removing point observations in 10% increments. This provides a comprehensive method of evaluating the impact of LiDAR ground point density on DTM accuracy. While the reduction of point density leads to a less accurate DTM in all cases (as expected), the exact pattern varies by algorithm. The accuracy of the LiDAR-derived DTMs is relatively good even when LiDAR sampling density is reduced to 0.40–0.50 points/m2 (50–60 % of the initial point density), as long as a suitable interpolation algorithm is used (as IDW proved to be less resilient to density reductions below approximately 0.60 points/m2). In the case of slope estimation, the pattern is relatively similar, except the difference in accuracy between IDW and the other two algorithms is even more pronounced than in the case of DTM accuracy. Based on this research, we conclude that LiDAR is an adequate method for collecting morphological data necessary for modelling the ground surface, even when the sampling density is significantly reduced.

scholarly journals The Effect of Repeated Whole-Body Cryotherapy on Sirt1 and Sirt3 Concentrations and Oxidative Status in Older and Young Men Performing Different Levels of Physical Activity

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Gabriela Wojciak ◽  
Jadwiga Szymura ◽  
Zbigniew Szygula ◽  
Joanna Gradek ◽  
Magdalena Wiecek
Keyword(s):  
Physical Activity ◽  
Young Men ◽  
Oxidative Status ◽  
Whole Body ◽  
Stress Index ◽  
Blood Levels ◽  
Long Distance ◽  
Antioxidant Defence ◽  
Whole Body Cryotherapy ◽  
The Impact

Background: The activity of antioxidant enzymes and sirtuins (Sirt) decreases along with age, which is counteracted by aerobic training. Sirtuins increase antioxidant defence. Whole-body cryotherapy (WBC) increases total antioxidant capacity (TAC) in young men. The aim of our study was to assess the impact of 24 WBC treatments on the blood concentration of selected sirtuins and the level of antioxidant defence as well as oxidative stress index of training and non-training men depending on age. Methods: The study involved 40 males. In each group, there were 10 non-training older and young men (60 NTR and 20 NTR), and 10 older and young long-distance runners (60 TR, 20 TR). During an 8-week period, participants underwent 24 WBC treatments (3 min −130 °C), which were performed three times a week (Monday, Wednesday, Friday). The concentrations of Sirt1, Sirt3, TAC, total oxidative status and the activity of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in the blood were determined before 1 WBC and after 1 WBC, 12 WBC and 24 WBC. Results: After 1 WBC, the activity of GPx and the concentration of Sirt1 and TAC in 60 TR and TAC in 60 NTR increased. After 12 WBC, the level of Sirt1 in 20 NTR and SOD in 20 TR increased. After 24 WBC, the level of Sirt1 increased in 60 TR and in 20 NTR, Sirt3 in 60 TR and SOD in 20 TR. Conclusions: Cryogenic temperatures increase blood levels of Sirt1 and Sirt3 and systemic antioxidant defence in men, but the effect is dependent on age, level of performed physical activity and the number of applied treatments.

scholarly journals Modular Approach to Ultra-fast Charging Stations

2021 ◽  
Author(s):  
Carola Leone ◽  
Michela Longo
Keyword(s):  
Impact Analysis ◽  
Road Transport ◽  
Modular Approach ◽  
Long Distance ◽  
Charging Infrastructure ◽  
Charging Station ◽  
Fast Charging ◽  
Modular Architectures ◽  
The Impact ◽  
Fast Charging Station

AbstractRoad transport electrification is essential for meeting the European Union's goals of decarbonization and climate change. In this context, an Ultra-Fast Charging (UFC) system is deemed necessary to facilitate the massive penetration of Electric Vehicles (EVs) on the market; particularly as medium-long distance travels are concerned. Anyway, an ultra-fast charging infrastructure represents the most critical point as regards hardware technology, grid-related issues, and financial sustainability. Thus far, this paper presents an impact analysis of a fast-charging station on the grid in terms of power consumption, obtained by the Monte Carlo simulation. Simulation results show that it is not economical convenient size the assumed ultra-fast charging station for the maximum possible power also considering its high impact on the grid. In view of the results obtained from the impact analysis, the last part of the paper focuses on finding a method to reduce the power installed for the DC/DC stage while keeping the possibility for the electric vehicle to charge at their maximum power. To achieve this goal a modular approach is proposed. Finally, two different modular architectures are presented and compared. In both the solutions, the probability of having EVs charging at limited power is less than 5%.

scholarly journals Analysis of the Impact of a Multi-Strain Probiotic on Body Composition and Cardiorespiratory Fitness in Long-Distance Runners

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3758
Author(s):  
Joanna Smarkusz-Zarzecka ◽  
Lucyna Ostrowska ◽  
Joanna Leszczyńska ◽  
Karolina Orywal ◽  
Urszula Cwalina ◽  
...  
Keyword(s):  
Body Composition ◽  
Cardiorespiratory Fitness ◽  
The Body ◽  
Double Blind Study ◽  
Distance Runners ◽  
Long Distance ◽  
Double Blind ◽  
Necrosis Factor Alpha ◽  
Total Body ◽  
The Impact

Use of probiotic supplements, the benefits of which have not been proven in sportspeople, is becoming more widespread among runners. The aim of this study was to evaluate the effect of a multi-strain probiotic on body composition, cardiorespiratory fitness and inflammation in the body. The randomised, double-blind study included 66 long-distance runners. The intervention factor was a multi-strain probiotic or placebo. At the initial and final stages of the study, evaluation of body composition and cardiorespiratory fitness was performed and the presence of inflammation determined. In the group of men using the probiotic, an increase in lean body mass (p = 0.019) and skeletal muscle mass (p = 0.022) was demonstrated, while in the group of women taking the probiotic, a decrease in the content of total body fat (p = 0.600) and visceral fat (p = 0.247) was observed. Maximum oxygen consumption (VO2max) increased in women (p = 0.140) and men (p = 0.017) using the probiotic. Concentration of tumour necrosis factor-alpha decreased in women (p = 0.003) and men (p = 0.001) using the probiotic and in women (p = 0.074) and men (p = 0.016) using the placebo. Probiotic therapy had a positive effect on selected parameters of body composition and cardiorespiratory fitness of study participants and showed a tendency to reduce inflammation.

Sign in / Sign up

Export Citation Format

Share Document