Exercise in Giraffes

2021 ◽  
pp. 292-315
Author(s):  
Graham Mitchell
Keyword(s):  
Aerobic Exercise ◽  
High Speed ◽  
Oxygen Demand ◽  
Running Economy ◽  
Anaerobic Exercise ◽  
Metabolic Energy ◽  
Fiber Types ◽  
Metabolic Demand ◽  
High Speeds ◽  
Anaerobic Energy

Observation of giraffes reveal that they can run at very high speeds (~60 km h–1) for short periods (~5 minutes) but can also run at lower speeds (40 km h–1) for much longer periods. This combination of these two types of exercise capabilities is unusual. Their short periods of high speed running have the characteristics of anaerobic exercise. Analysis of the fiber types in their gastrocnemius muscle, and estimates of the available anaerobic energy sources support that conclusion. Longer periods depend on aerobic exercise and requires an adequate supply of oxygen to the lungs, adequate delivery of oxygen to muscles, and sufficient mitochondria to use oxygen. Despite the limitations of giraffe airway and lung anatomy the respiratory system of giraffes can supply sufficient oxygen. The volume of mitochondria in giraffe muscles far exceeds the volume required for maximum aerobic exercise. The cardiovascular system has evolved to generate high blood pressure rather than the circulation of high blood volumes, but if the maximum cardiac output is combined with an increase in the number of circulating erythrocytes, then oxygen delivery to muscles can match oxygen demand. Metabolic demand for oxygen can be reduced by an increase in running economy through storage of metabolic energy as elastic energy in tendons, and it is likely that because leg tendons of giraffes are long (~2 m) that the requirement for metabolic energy can be reduced by 30–40%.

Anaerobic exercise in teleost fish

1982 ◽  
Vol 60 (5) ◽  
pp. 1131-1134 ◽  
Author(s):  
David R. Jones
Keyword(s):  
Teleost Fish ◽  
High Speed ◽  
Swimming Performance ◽  
Anaerobic Exercise ◽  
Glycogen Depletion ◽  
Sufficient Power ◽  
Anaerobic Energy ◽  
Blood Haemoglobin ◽  
Burst Swimming ◽  
Steady Performance

In teleost fish, high speed ("burst") swimming is performed anaerobically while sustained performance is aerobic. The degree to which anaerobic energy production contributes to swimming performance in the steady exercise zone (swimming maintained for 2 to 200 min) in unknown. The relationship between oxygen consumption or scope for activity and swimming speed (U), the repayment of an oxygen debt during recovery from fatigue, and the reduction in maximum sustained speed (critical velocity, Ucrit) by reduced environmental oxygen or lowered blood haemoglobin suggest that steady performance in salmonids is aerobic. In salmonids, sufficient power is provided from the oxygen consumed to swim steadily at least at 80% of Ucrit. On the other hand, depending on the temperature, aerobic power output in cyprinids is only sufficient to reach 30–50% of Ucrit. Aerobic relationships holding for salmonids do not apply to cyprinids. In fact, high respiratory quotients early in exercise along with glycogen depletion and lactate accumulation rates in muscle during vigorous swimming suggest that steady performance in cyprinids is worthy of further examination.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

RED CUT COBALT

Alloy Digest ◽  
1980 ◽  
Vol 29 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Cast Iron ◽  
High Speed ◽  
Elevated Temperatures ◽  
High Speed Steel ◽  
Heat Treating ◽  
High Speeds ◽  
Red Hardness ◽  
Nonferrous Alloys ◽  
Cutting Point

Abstract RED CUT COBALT steel is made by adding 5% cobalt to the conventional 18% tungsten -4% chromium-1% vanadium high-speed steel. Cobalt increases hot or red hardness and thus enables the tool to maintain a higher hardness at elevated temperatures. This steel is best adapted for hogging cuts or where the temperature of the cutting point of the tool in increased greatly. It is well adapted for tools to be used for reaming cast-iron engine cylinders, turning alloy steel or cast iron and cutting nonferrous alloys at high speeds. This datasheet provides information on composition, physical properties, and hardness as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-367. Producer or source: Teledyne Vasco.

CPM REX 25

Alloy Digest ◽  
1980 ◽  
Vol 29 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
High Speed Steel ◽  
High Hardness ◽  
Heat Treating ◽  
High Speeds ◽  
Aisi Type ◽  
Tool Performance ◽  
End Mills ◽  
Machining Operations

Abstract CPM REX 25 is a super high-speed steel made without cobalt. It is comparable to AISI Type T15 cobalt-containing high-speed steel in response to heat treatment, properties, and tool performance. CPM REX 25 is recommended for machining operations requiring heavy cuts, high speeds and feeds, and difficult-to-machine materials of high hardness and abrasion resistance. Typical applications are boring tools, drills, gear cutters, punches, form tools, end mills and broaches. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-365. Producer or source: Crucible Materials Corporation.

scholarly journals Pathophysiology and clinical consequences of arterial blood gases and pH after cardiac arrest

2020 ◽  
Vol 8 (S1) ◽  
Author(s):  
Chiara Robba ◽  
Dorota Siwicka-Gieroba ◽  
Andras Sikter ◽  
Denise Battaglini ◽  
Wojciech Dąbrowski ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Mechanical Ventilation ◽  
Cardiac Arrest ◽  
Oxygen Demand ◽  
Blood Gases ◽  
Metabolic Energy ◽  
High Morbidity ◽  
Arterial Blood Gases ◽  
Arterial Blood ◽  
Clinical Consequences

AbstractPost cardiac arrest syndrome is associated with high morbidity and mortality, which is related not only to a poor neurological outcome but also to respiratory and cardiovascular dysfunctions. The control of gas exchange, and in particular oxygenation and carbon dioxide levels, is fundamental in mechanically ventilated patients after resuscitation, as arterial blood gases derangement might have important effects on the cerebral blood flow and systemic physiology.In particular, the pathophysiological role of carbon dioxide (CO2) levels is strongly underestimated, as its alterations quickly affect also the changes of intracellular pH, and consequently influence metabolic energy and oxygen demand. Hypo/hypercapnia, as well as mechanical ventilation during and after resuscitation, can affect CO2 levels and trigger a dangerous pathophysiological vicious circle related to the relationship between pH, cellular demand, and catecholamine levels. The developing hypocapnia can nullify the beneficial effects of the hypothermia. The aim of this review was to describe the pathophysiology and clinical consequences of arterial blood gases and pH after cardiac arrest.According to our findings, the optimal ventilator strategies in post cardiac arrest patients are not fully understood, and oxygen and carbon dioxide targets should take in consideration a complex pattern of pathophysiological factors. Further studies are warranted to define the optimal settings of mechanical ventilation in patients after cardiac arrest.

A Method of Making High-Speed Compression Tests on Small Copper Cylinders

1948 ◽  
Vol 15 (3) ◽  
pp. 248-255
Author(s):  
E. T. Habib
Keyword(s):  
High Speed ◽  
Underwater Explosion ◽  
Dynamic Calibration ◽  
Test Apparatus ◽  
Compression Tests ◽  
High Speeds

Abstract In mechanical gages used to measure the pressure from an underwater explosion, small copper cylinders are compressed at high speeds. This paper describes the test apparatus designed for the dynamic calibration of these cylinders, presents the results obtained with this apparatus, and compares these results with those obtained by other experimenters.

Stability of Water-Lubricated, Hydrostatic, Conical Bearings With Spiral Grooves for High-Speed Spindles

2001 ◽  
Vol 124 (2) ◽  
pp. 398-405 ◽  
Author(s):  
S. Yoshimoto ◽  
S. Oshima ◽  
S. Danbara ◽  
T. Shitara
Keyword(s):  
High Speed ◽  
Water Pressure ◽  
Rotating Shaft ◽  
Pressurized Water ◽  
High Speeds ◽  
Theoretical Predictions ◽  
The Stability ◽  
Stability Of Water ◽  
Spiral Grooves ◽  
Good Agreement

In this paper, the stability of water-lubricated, hydrostatic, conical bearings with spiral grooves for high-speed spindles is investigated theoretically and experimentally. In these bearing types, pressurized water is first fed to the inside of the rotating shaft and then introduced into spiral grooves through feeding holes located at one end of each spiral groove. Therefore, water pressure is increased due to the effect of the centrifugal force at the outlets of the feeding holes, which results from shaft rotation. In addition, water pressure is also increased by the viscous pumping effect of the spiral grooves. The stability of the proposed bearing is theoretically predicted using the perturbation method, and calculated results are compared with experimental results. It was consequently found that the proposed bearing is very stable at high speeds and theoretical predictions show good agreement with experimental data.

scholarly journals Comparison of Serum HIF-1α Levels in Swimming Athletes Before and After Hypoxic Non-Hypoxic Exercise

2020 ◽  
Vol 21 (1) ◽  
pp. 36-39
Author(s):  
Syahrastani Syahrastani ◽  
Argantos Argantos ◽  
Siska Alicia Farma
Keyword(s):  
Aerobic Exercise ◽  
The Body ◽  
Anaerobic Exercise ◽  
Adaptation To Hypoxia ◽  
Cross Sectional ◽  
Hypoxic Conditions ◽  
Before And After ◽  
Cross Sectional Design ◽  
Age Range ◽  
Hypoxic Exercise

The situation of lack of oxygen supply to cells and tissues is often not realized by many people (hypoxia). Hypoxia can occur in various situations in life. The main effect of hypoxia is the effect on the brain, so the body will do everything it can to restore the state of homeostasis. HIF-1α protein is a marker of hypoxic conditions. HIF-1α regulates the synthesis of many genes to maintain and restore body homeostasis from hypoxia to normoxia. This study was a descriptive study with cross-sectional design. The sample of this study were six swimming athletes with a 12-19 year age range who met the inclusion and exclusion criteria. The HIF-1α protein is measured by the ELISA method. Data were analyzed statistically. The results showed higher levels of HIF-1α after anaerobic exercise than the levels of HIF-1α before and after aerobic exercise. This is greatly influenced by the intensity of the exercise carried out. This proves that cellular adaptation to hypoxia is more stable in aerobic exercise, where the body's metabolism during aerobic exercise is more stable  

scholarly journals β-endorphin response to aerobic and anaerobic exercises in Wistar male rats

2020 ◽  
Vol 29 (3) ◽  
pp. 245-9
Author(s):  
Rostika Flora ◽  
Mohammad Zulkarnain ◽  
Sukirno
Keyword(s):  
Physical Exercise ◽  
Aerobic Exercise ◽  
Brain Tissue ◽  
Exercise Group ◽  
Anaerobic Exercise ◽  
Treadmill Running ◽  
Male Rats ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Aerobic And Anaerobic

BACKGROUND Physical exercise is strongly associated with the release of β-endorphin. It is assumed that the type and intensity of physical exercise contributes to the release of β-endorphin. This study aimed to compare levels of β-endorphin in brain tissue in response to aerobic and anaerobic physical exercise. METHODS This study was an experimental laboratory study using 35 male Wistar rats divided into one control group and two physical exercise treatment groups: aerobic and anaerobic. Physical exercise was conducted on an animal treadmill running at aspeed of 20 m/min for 30 min of aerobic exercise and 35 m/min with 1-min intervals every 5 min for 20 min for anaerobic exercises. Each aerobic and anaerobic exercise group was furtherly classified into three subgroups (1×/week, 3×/week, and 7×/week). β-endorphin levels were determined using enzyme-linked immunosorbent assay. The data were analyzed using independent t-test and one-way analysis of variance. RESULTS The highest mean of β-endorphin level was found in the weekly exercise (54.45 [1.41] pg/ml) of aerobic exercise group and daily exercise (70.50 [11.67] pg/ml) of anaerobic exercise group. Mean of β-endorphin level in control group was 33.34 (3.54) pg/ml. A significant increased of β-endorphin mean level (p<0.001) was found in all aerobic and anaerobic exercise groups except the aerobic exercise 7×/week group(37.37 [6.30] pg/ml) compared to control. CONCLUSIONS Both aerobic and anaerobic physical exercise conducted for 6 weeks could increase the level of β-endorphin in brain tissue.

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