scholarly journals Non-invasive MRI Studies of Ventilatory and Cardiovascular Performance in Edible Crabs Cancer pagurus During Warming Under Elevated CO2 Levels

2021 ◽  
Vol 11 ◽  
Author(s):  
Bastian Maus ◽  
Sebastian Gutsfeld ◽  
Christian Bock ◽  
Hans-Otto Pörtner
Keyword(s):  
Oxygen Uptake ◽  
Thermal Tolerance ◽  
Decapod Crustacean ◽  
Temperature Dependent ◽  
Non Invasive ◽  
Cancer Pagurus ◽  
Decapod Crustacea ◽  
Infra Red ◽  
Cardiovascular Performance ◽  
Flow Through

The thermal tolerance of marine decapod crustacea is defined through their capacities for oxygen uptake and distribution. High ambient CO2 levels were previously shown to reduce hemolymph oxygen levels at enhanced cardiac performance during warming. This study investigated the impacts of warming under two CO2 levels on ventilation and hemolymph circulation in edible crabs Cancer pagurus. It also highlights changes in the ventilatory and cardiac pauses displayed by Decapoda under routine metabolism. Animals were exposed to step-wise, sub-critical warming (12–20°C over 5 days) under control (470 μatm) and high (1,350 μatm) water PCO2. Flow-through respirometry was combined with magnetic resonance imaging and infra-red photoplethysmography to allow for simultaneous, non-invasive measurements of metabolic rates (M˙O2), ventilation and cardiovascular performance. Crabs spent significantly more time in a low M˙O2 state (metabolic pause), when experiencing high CO2 conditions above 16°C, compared to normocapnic warming. Heart rates leveled off beyond 18°C at any CO2 level. Cardiac output continued to increase with high-CO2-warming, due to elevated cardiac stroke volumes. Consequently, temperature-dependent branchial hemolymph flow remained unaffected by CO2. Instead, a suppressing effect of CO2 on ventilation was found beyond 16°C. These results indicate constrained oxygen uptake at stable cardiovascular performance in a decapod crustacean.Cancer pagurus: urn:lsid:zoobank.org:act:B750F89A-84B5-448B-8D80-EBD724A1C9D4

scholarly journals Spectral Decomposition of the Flow and Characterization of the Sound Signals through Stenoses with Different Levels of Severity

2021 ◽  
Vol 8 (3) ◽  
pp. 41
Author(s):  
Fardin Khalili ◽  
Peshala T. Gamage ◽  
Amirtahà Taebi ◽  
Mark E. Johnson ◽  
Randal B. Roberts ◽  
...  
Keyword(s):  
Pressure Fluctuations ◽  
High Energy ◽  
Sound Sources ◽  
Severity Level ◽  
Non Invasive ◽  
Flow Through ◽  
Severity Of The Disease ◽  
Proper Orthogonal ◽  
Different Levels

Treatments of atherosclerosis depend on the severity of the disease at the diagnosis time. Non-invasive diagnosis techniques, capable of detecting stenosis at early stages, are essential to reduce associated costs and mortality rates. We used computational fluid dynamics and acoustics analysis to extensively investigate the sound sources arising from high-turbulent fluctuating flow through stenosis. The frequency spectral analysis and proper orthogonal decomposition unveiled the frequency contents of the fluctuations for different severities and decomposed the flow into several frequency bandwidths. Results showed that high-intensity turbulent pressure fluctuations appeared inside the stenosis for severities above 70%, concentrated at plaque surface, and immediately in the post-stenotic region. Analysis of these fluctuations with the progression of the stenosis indicated that (a) there was a distinct break frequency for each severity level, ranging from 40 to 230 Hz, (b) acoustic spatial-frequency maps demonstrated the variation of the frequency content with respect to the distance from the stenosis, and (c) high-energy, high-frequency fluctuations existed inside the stenosis only for severe cases. This information can be essential for predicting the severity level of progressive stenosis, comprehending the nature of the sound sources, and determining the location of the stenosis with respect to the point of measurements.

Effects of recent thermal history on thermal behaviour, thermal tolerance and oxygen uptake of Yellowtail Kingfish (Seriola lalandi) juveniles

2021 ◽  
pp. 103023
Author(s):  
Ernesto Larios-Soriano ◽  
Ana Denisse Re-Araujo ◽  
Fernando Díaz ◽  
Laura L. López-Galindo ◽  
Carlos Rosas ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Thermal Behaviour ◽  
Thermal History ◽  
Thermal Tolerance ◽  
Yellowtail Kingfish ◽  
Seriola Lalandi

scholarly journals Barrier Evaluation by Linearly Increasing Voltage Technique Applied to Si Solar Cells and Irradiated Pin Diodes

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
E. Gaubas ◽  
T. Ceponis ◽  
V. Kalendra ◽  
J. Kusakovskij ◽  
A. Uleckas
Keyword(s):  
Solar Cells ◽  
Temperature Dependent ◽  
Particle Detectors ◽  
Si Solar Cells ◽  
Diffusion Capacitance ◽  
Barrier Capacitance ◽  
Infra Red ◽  
The Impact ◽  
And Diffusion ◽  
Current Transients

Technique for barrier evaluation by measurements of current transients induced by linearly increasing voltage pulse based on analysis of barrier and diffusion capacitance changes is presented. The components of the barrier capacitance charging and generation/recombination currents are discussed. Different situations of the impact of deep center defects on barrier and diffusion capacitance changes are analyzed. Basics of the profiling of layered junction structures using the presented technique are discussed. Instrumentation for implementation of this technique and for investigations of the steady-state bias infra-red illumination and temperature dependent variations of the barrier capacitance charging and generation/recombination currents are described. Applications of this technique for the analysis of barrier quality in solar cells and particle detectors fabricated on silicon material are demonstrated.

Application and In situ calibration of a pulsed-doppler flowmeter for blood flow measurement in crustaceans

1994 ◽  
Vol 74 (2) ◽  
pp. 455-458 ◽  
Author(s):  
C.N. Airriess ◽  
B.R. McMahon ◽  
I.J. McGaw ◽  
G.B. Bourne
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
The Body ◽  
Pulsed Doppler ◽  
Arterial Perfusion ◽  
Non Invasive ◽  
In Situ Calibration ◽  
Flow Through ◽  
Doppler Flowmeter

The pulsed-Doppler flowmeter permits continuous, non-invasive measurement of blood flow through several arteries simultaneously. Summation of volume flow rates through all arteries leaving the heart allows determination of cardiac output, stroke volume, and the percentage of cardiac output delivered to each region of the body. The use of this system for investigating changes in arterial perfusion as well as its calibration in situ are described.

Practical infra-red illumination and observation techniques for wildlife studies using ICI-962 perspex

2003 ◽  
Vol 25 (2) ◽  
pp. 201 ◽  
Author(s):  
C Marks ◽  
F Busana ◽  
F Gigliotti ◽  
M Lindeman
Keyword(s):  
Uv Light ◽  
Ultra Violet ◽  
Ir Radiation ◽  
Long Wavelength ◽  
Non Invasive ◽  
Radiation Sources ◽  
Infra Red ◽  
Invaluable Tool ◽  
Free Ranging ◽  
Wavelength Light

MAMMALS do not normally visually perceive infrared (IR) or ultra-violet (UV) light that exists on either side of the visual spectrum from 390 to 760 nanometers (nm) (Wolken 1975). There is no evidence to suggest that nocturnal mammals have become more sensitive to long wavelength light as an adaptive response (Lythgoe 1979), although some reptiles can sense longer wavelength, thermal IR radiation (Barrett et al. 1970). Because it is not perceived, and is unlikely to affect animal behaviour, IR observation can be an invaluable tool for wildlife researchers. This paper describes the construction and use of simple IR radiation sources that can be used for non-invasive behavioural observations of captive and free-ranging mammals.

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