Using an acoustic telemetry array to assess fish volumetric space use: a case study on impoundments, hypoxia and an air-breathing species (Neoceratodus forsteri)

2017 ◽  
Vol 68 (8) ◽  
pp. 1532 ◽  
Author(s):  
D. T. Roberts ◽  
V. Udyawer ◽  
C. Franklin ◽  
R. G. Dwyer ◽  
H. A. Campbell
Keyword(s):  
Atmospheric Oxygen ◽  
Habitat Preferences ◽  
Three Dimensional ◽  
Depth Sensor ◽  
Experimental Conditions ◽  
Air Breathing ◽  
Hypoxic Conditions ◽  
Hypoxic Zone ◽  
Increasing Demand ◽  
Oxygen Requirements

Facultative air-breathing fish can persist in hypoxic waters due to their capacity to acquire atmospheric oxygen. Most studies examining responses of air-breathing fish to aquatic hypoxia have occurred under experimental conditions. How air-breathing fish respond to hypoxic conditions in the field has received less attention. Using depth sensor transmitters and an array of acoustic receivers to monitor the facultative air-breathing Australian lungfish (Neoceratodus forsteri), we investigated habitat preferences and behavioural responses to seasonal hypoxic zones in a riverine impoundment. Three-dimensional (3-D) kernel utilisation distribution (KUD) models revealed that during stratified conditions, lungfish remained above the oxycline, rarely venturing into hypoxic waters, whereas during holomixis lungfish used a wider range of depths. Total volumetric space utilisation did not change significantly during stratified periods, but the distribution of space used changed, constrained by the oxycline. Despite N. forsteri having lungs to supplement oxygen requirements, the presence of a hypoxic zone constrained the core (50% 3-D-KUD) volumetric space used by lungfish to <1.6% of the total available space of the study area. With increasing demand for new impoundments in many tropical and subtropical regions, the present study provides insights to how air-breathing fish species may respond to altered riverine conditions from impoundments.

Chronic Hypoxia as a Potential Factor in Human Life-threatening Diseases

2017 ◽  
Vol 10 (4) ◽  
pp. 3759-3762
Author(s):  
Sandhya MNVS ◽  
Vanitha K ◽  
Ramesh A
Keyword(s):  
Chronic Hypoxia ◽  
Atmospheric Oxygen ◽  
Human Life ◽  
The Body ◽  
Cellular Damage ◽  
Otto Warburg ◽  
Regular Treatment ◽  
Breathing Exercises ◽  
Hypoxic Conditions ◽  
Cancerous Cell

The review article focuses on the importance of adequate oxygen levels in the body as cure and therapy for many ailments. It is known that hypoxia is the cause for cellular damage and if it can be applied to major patho-physiology’s, it can be observed that slow and chronic hypoxic conditions are the cause for most of the diseases. On the contrary, providing each cell of the body with proper oxygen may be helpful in maintaining the immunity of the body and therefore treating many disease conditions. This theory, if tested may show positive results in heart related diseases, neuronal disorders, stresses, digestive disorders and the unresolved cancer too. Slow decrease in the levels of atmospheric oxygen could be a reason to induce chronic hypoxia. According to Dr. Otto Warburg, a Noble laurate, a normal cell when deprived of oxygen, may get converted to a cancerous cell, whereas a cancerous cell cannot survive in aerobic conditions. If this part of his research be concentrated on, there could be fruitful results in the treatment of cancer. To maintain adequate levels of oxygen in the body, simple yogic breathing practices are helpful. And to maintain the adequate atmospheric oxygen, trees and plants which cleanse the atmospheric air are useful. Clinical surveys on volunteers who have been practicing regular breathing exercises can prove the fact that proper and concentrated respiration could prevent many diseases. Thus, supplementing breathing exercises along with the regular treatment for cancer patients could be helpful in alleviating cancer and other diseases.

scholarly journals Numerical and experimental study on turbulence statistics in a large fan-stirred combustion vessel

2021 ◽  
Vol 62 (5) ◽  
Author(s):  
M. E. Morsy ◽  
J. Yang
Keyword(s):  
Isotropic Turbulence ◽  
Burning Velocity ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Turbulence Models ◽  
Initial Pressure ◽  
Dynamics Modeling ◽  
Turbulence Statistics ◽  
Experimental Conditions ◽  
Measured Velocity

Abstract Particle image velocimetry (PIV) has become a popular non-intrusive tool for measuring various types of flows. However, when measuring three-dimensional flows with two-dimensional (2D) PIV, there are some uncertainties in the measured velocity field due to out-of-plane motion, which might alter turbulence statistics and distort the overall flow characteristics. In the present study, three different turbulence models are employed and compared. Mean and fluctuating fields obtained by three-dimensional computational fluid dynamics modeling are compared to experimental data. Turbulence statistics such as integral length scale, Taylor microscale, Kolmogorov scale, turbulence kinetic energy, dissipation rate, and velocity correlations are calculated at different experimental conditions (i.e., pressure, temperature, fan speed, etc.). A reasonably isotropic and homogeneous turbulence with large turbulence intensities is achieved in the central region extending to almost 45 mm radius. This radius decreases with increasing the initial pressure. The influence of the third dimension velocity component on the measured characteristics is negligible. This is a result of the axisymmetric features of the flow pattern in the current vessel. The results prove that the present vessel can be conveniently adopted for several turbulent combustion studies including mainly the determination of turbulent burning velocity for gaseous premixed flames in nearly homogeneous isotropic turbulence. Graphic abstract

Secondary motion in convection layers generated by lateral heating of a solute gradient

2002 ◽  
Vol 455 ◽  
pp. 1-19 ◽  
Author(s):  
CHO LIK CHAN ◽  
WEN-YAU CHEN ◽  
C. F. CHEN
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Convection Cell ◽  
Experimental Conditions ◽  
Longitudinal Plane ◽  
Secondary Motion ◽  
Solute Gradient

The three-dimensional motion observed by Chen & Chen (1997) in the convection cells generated by sideways heating of a solute gradient is further examined by experiments and linear stability analysis. In the experiments, we obtained visualizations and PIV measurements of the velocity of the fluid motion in the longitudinal plane perpendicular to the imposed temperature gradient. The flow consists of a horizontal row of counter-rotating vortices within each convection cell. The magnitude of this secondary motion is approximately one-half that of the primary convection cell. Results of a linear stability analysis of a parallel double-diffusive flow model of the actual ow show that the instability is in the salt-finger mode under the experimental conditions. The perturbation streamlines in the longitudinal plane at onset consist of a horizontal row of counter-rotating vortices similar to those observed in the experiments.

THE IMMATURE STAGES OF PTYCHOPTERA LENIS LENIS (DIPTERA: PTYCHOPTERIDAE) WITH NOTES ON THEIR BIOLOGY

1973 ◽  
Vol 105 (8) ◽  
pp. 1091-1099 ◽  
Author(s):  
I. D. Hodkinson
Keyword(s):  
Life Cycle ◽  
Water Depth ◽  
Adult Stage ◽  
Atmospheric Oxygen ◽  
Adult Emergence ◽  
Fourth Instar ◽  
Immature Stages ◽  
Experimental Conditions ◽  
Marginal Areas ◽  
Pharate Adult

AbstractThe four larval instars and the pupa of Ptychoptera lenis lenis Osten Sacken are described. Instars 2 to 4 are very similar morphologically but instar 1 is markedly different. Both a pharate pupal and a pharate adult stage were observed. Larvae are found in stagnant marginal areas of ponds where water depth does not exceed 4 cm and where benthic deposits of plant detritus exceed 8 cm. Fourth instar larvae, under experimental conditions, survived up to 45 days without contact with atmospheric oxygen but development was arrested. P. lenis has a 1 year life cycle with an extended adult emergence season from late May to the end of July.

Design and preparation of three-dimensional MnO/N-doped carbon nanocomposites based on waste biomass for high storage and ultra-fast transfer of lithium ions

2018 ◽  
Vol 6 (40) ◽  
pp. 19479-19487 ◽  
Author(s):  
Qiaoxia Feng ◽  
Huanxin Li ◽  
Zhong Tan ◽  
Zhongyuan Huang ◽  
Lanlan Jiang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Three Dimensional ◽  
Waste Biomass ◽  
Energy Storage Devices ◽  
Lithium Ions ◽  
Carbon Nanocomposites ◽  
Storage Devices ◽  
Fast Charging ◽  
Increasing Demand ◽  
High Storage

Batteries with fast charging capability are urgently needed to meet the rapidly increasing demand for energy storage devices.

Pathways for urea production during early life of an air-breathing teleost, the African catfish Clarias gariepinus Burchell

2001 ◽  
Vol 204 (12) ◽  
pp. 2155-2165 ◽  
Author(s):  
Bendik F. Terjesen ◽  
Terry D. Chadwick ◽  
Johan A. J. Verreth ◽  
Ivar Rønnestad ◽  
Patricia A. Wright
Keyword(s):  
Early Development ◽  
Early Life ◽  
Developmental Stages ◽  
Clarias Gariepinus ◽  
African Catfish ◽  
Life Stages ◽  
Carbamoyl Phosphate ◽  
Experimental Conditions ◽  
Air Breathing ◽  
Urea Production

SUMMARY Embryos and larvae of the African catfish Clarias gariepinus excrete significant quantities of urea. The present study focused on the potential urea-generating pathways during early development of this teleost; uricolysis, argininolysis and the ornithine–urea cycle (OUC). Uricase, allantoinase, allantoicase and ureidoglycollate lyase of the uricolytic pathway were expressed in all early life stages and in adult liver of C. gariepinus. Uricase activity increased in starved larvae compared with yolk-sac larvae. The key regulatory enzyme of the teleost OUC, carbamoyl phosphate synthetase III (CPSase III), was expressed predominantly in muscle of developing C. gariepinus larvae and showed negligible activity in the absence of its allosteric effector N-acetyl-l-glutamate. CPSase III and ornithine carbamoyl transferase activities increased in fed larvae compared with starved larvae. In contrast to the early developmental stages, adult C. gariepinus expressed only low and variable levels of CPSase III, suggesting that, under the experimental conditions employed, OUC expression is influenced by developmental stage in this species. The data indicate that early C. gariepinus life stages express the enzymes necessary for urea production by uricolysis, argininolysis and the OUC, and this may explain why urea tissue levels and urea excretion rates are substantial during the early development of this air-breathing teleost.

scholarly journals Trajectory-Based Air-Writing Recognition Using Deep Neural Network and Depth Sensor

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 376 ◽  
Author(s):  
Md. Shahinur Alam ◽  
Ki-Chul Kwon ◽  
Md. Ashraful Alam ◽  
Mohammed Y. Abbass ◽  
Shariar Md Imtiaz ◽  
...  
Keyword(s):  
Neural Network ◽  
Nearest Neighbor ◽  
Short Term Memory ◽  
Three Dimensional ◽  
Recognition System ◽  
Writing Systems ◽  
Depth Sensor ◽  
Handheld Device ◽  
Proposed Model ◽  
Long Short Term Memory

Trajectory-based writing system refers to writing a linguistic character or word in free space by moving a finger, marker, or handheld device. It is widely applicable where traditional pen-up and pen-down writing systems are troublesome. Due to the simple writing style, it has a great advantage over the gesture-based system. However, it is a challenging task because of the non-uniform characters and different writing styles. In this research, we developed an air-writing recognition system using three-dimensional (3D) trajectories collected by a depth camera that tracks the fingertip. For better feature selection, the nearest neighbor and root point translation was used to normalize the trajectory. We employed the long short-term memory (LSTM) and a convolutional neural network (CNN) as a recognizer. The model was tested and verified by the self-collected dataset. To evaluate the robustness of our model, we also employed the 6D motion gesture (6DMG) alphanumeric character dataset and achieved 99.32% accuracy which is the highest to date. Hence, it verifies that the proposed model is invariant for digits and characters. Moreover, we publish a dataset containing 21,000 digits; which solves the lack of dataset in the current research.

scholarly journals Three-Dimensional Flow Characteristics in Slit-Type Permeable Spur Dike Fields: Efficacy in Riverbank Protection

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 964 ◽  
Author(s):  
Shampa ◽  
Yuji Hasegawa ◽  
Hajime Nakagawa ◽  
Hiroshi Takebayashi ◽  
Kenji Kawaike
Keyword(s):  
Shear Stress ◽  
Longitudinal Velocity ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Efficient Solutions ◽  
Staggered Grid ◽  
Bed Shear Stress ◽  
Experimental Conditions ◽  
Alluvial Rivers ◽  
Spur Dike

This paper focuses on finding efficient solutions for the design of a highly permeable pile spur (or slit type) dike field used in morphologically dynamic alluvial rivers. To test the suitability of different arrangements of this type of permeable pile spur dike field, laboratory experiments were conducted, and a three-dimensional multiphase numerical model was developed and applied, based on the experimental conditions. Three different angles to the approach flow and two types of individual pile position arrangements were tested. The results show that by using a series of slit-type spurs, the approach velocity of the flow can be considerably reduced within the spur dike zone. Using different sets of angles and installation positions, this type of permeable spur dike can be used more efficiently than traditional dikes. Notably, this type of spur dike can reduce the longitudinal velocity, turbulence intensity, and bed shear stress in the near-bank area. Additionally, the deflection of the permeable spur produces more transverse flow to the opposite bank. Arranging the piles in staggered grid positions among different spurs in a spur dike field improves functionality in terms of creating a quasi-uniform turbulence zone while simultaneously reducing the bed shear stress. Finally, the efficacy of the slit-type permeable spur dike field as a solution to the riverbank erosion problem is numerically tested in a reach of a braided river, the Brahmaputra–Jamuna River, and a comparison is made with a conventional spur dike field. The results indicate that the proposed structure ensures the smooth passing of flow compared with that for the conventional impermeable spur structure by producing a lower level of scouring (low bed shear stress) and flow intensification.

Sign in / Sign up

Export Citation Format

Share Document