scholarly journals Mechanics of lung ventilation in a large aquatic salamander, siren lacertina

1998 ◽  
Vol 201 (5) ◽  
pp. 673-682 ◽  
Author(s):  
E L Brainerd ◽  
J A Monroy
Keyword(s):  
Lung Ventilation ◽  
Active Phase ◽  
Body Cavity ◽  
Intermediate Step ◽  
Cavity Pressure ◽  
Mixed Gas ◽  
Necturus Maculosus ◽  
Axial Muscles ◽  
Two Phases ◽  
Internal Oblique

Lung ventilation in Siren lacertina was studied using X-ray video, measurements of body cavity pressure and electromyography of hypaxial muscles. S. lacertina utilizes a two-stroke buccal pump in which mixing of expired and inspired gas is minimized by partial expansion of the buccal cavity during exhalation and then full expansion after exhalation is complete. Mixing is further reduced by the use of one or two accessory inspirations after the first, mixed-gas cycle. Exhalation occurs in two phases: a passive phase in which hydrostatic pressure and possibly lung elasticity force air out of the lungs, and an active phase in which contraction of the transverse abdominis (TA) muscle increases body cavity pressure and forces most of the remaining air out. In electromyograms of the lateral hypaxial musculature, the TA became active 200-400 ms before the rise in body cavity pressure, and activity ceased at peak pressure. The TA was not active during inspiration, and no consistent activity during breathing was noted in the external oblique, internal oblique and rectus abdominis muscles. The finding that the TA is the primary expiratory muscle in S. lacertina agrees with findings in a previous study of another salamander, Necturus maculosus. Together, these results indicate that the use of the TA for exhalation is a primitive character for salamanders and support the hypothesis that the breathing mechanism of salamanders represents an intermediate step in evolution between a buccal pump, in which only head muscles are used for ventilation, and an aspiration pump, in which axial muscles are used for both exhalation and inhalation. <P>

Breathing movements in the frog Rana pipiens. I. The mechanical events associated with lung and buccal ventilation

1975 ◽  
Vol 53 (3) ◽  
pp. 332-344 ◽  
Author(s):  
N. H. West ◽  
D. R. Jones
Keyword(s):  
Rana Pipiens ◽  
Buccal Cavity ◽  
Lung Ventilation ◽  
Cavity Pressure ◽  
Normal Pattern ◽  
Large Pressure ◽  
Dilator Muscle ◽  
Recovery Stroke ◽  
Two Phases ◽  
Low Pressures

The normal pattern of breathing movements in Rana pipiens has been studied by recording pressure and volume changes in the buccal cavity and lungs, and electromyograms from the muscles involved in this activity. Two types of breathing movement were obtained, one concerned with ventilation of the buccal cavity (buccal cycles) and the other with lung ventilation (lung cycles). Only in the latter type of movement were the nares and glottis actively involved. During buccal cycles the nares remained open and the glottis closed, so although excursions of the buccal floor were some two-thirds of the magnitude of those occurring during lung cycles, only low pressures were generated. The onset of a lung cycle was signalled by activity in the laryngeal dilator muscle. When the glottis opened, lung pressure and volume decreased, and buccal cavity pressure and volume increased. After closure of the nares, the buccal floor was rapidly elevated by the activity of the breathing muscles and air was forced into the lungs from the buccal cavity. At peak pressure in the lungs and buccal cavity the glottis closed and nares opened. The recovery stroke of the buccal pump was passive. No evidence was found for large pressure differentials between the buccal cavity and lungs when the glottis was open, and air-flow recordings at the external nares showed two phases of flow during each buccal cycle and four phases with each lung ventilation cycle.

Mechanics of lung ventilation in a post-metamorphic salamander, Ambystoma Tigrinum

2000 ◽  
Vol 203 (6) ◽  
pp. 1081-1092 ◽  
Author(s):  
R.S. Simons ◽  
W.O. Bennett ◽  
E.L. Brainerd
Keyword(s):  
Aquatic Environment ◽  
Lung Ventilation ◽  
Body Cavity ◽  
Transversus Abdominis ◽  
Ambystoma Tigrinum ◽  
Emg Activity ◽  
Cavity Pressure ◽  
X Ray ◽  
Tiger Salamanders ◽  
Aquatic Salamanders

The mechanics of lung ventilation in frogs and aquatic salamanders has been well characterized, whereas lung ventilation in terrestrial-phase (post-metamorphic) salamanders has received little attention. We used electromyography (EMG), X-ray videography, standard videography and buccal and body cavity pressure measurements to characterize the ventilation mechanics of adult (post-metamorphic) tiger salamanders (Ambystoma tigrinum). Three results emerged: (i) under terrestrial conditions or when floating at the surface of the water, adult A. tigrinum breathed through their nares using a two-stroke buccal pump; (ii) in addition to this narial two-stroke pump, adult tiger salamanders also gulped air in through their mouths using a modified two-stroke buccal pump when in an aquatic environment; and (iii) exhalation in adult tiger salamanders is active during aquatic gulping breaths, whereas exhalation appears to be passive during terrestrial breathing at rest. Active exhalation in aquatic breaths is indicated by an increase in body cavity pressure during exhalation and associated EMG activity in the lateral hypaxial musculature, particularly the M. transversus abdominis. In terrestrial breathing, no EMG activity in the lateral hypaxial muscles is generally present, and body cavity pressure decreases during exhalation. In aquatic breaths, tidal volume is larger than in terrestrial breaths, and breathing frequency is much lower (approximately 1 breath 10 min(−)(1)versus 4–6 breaths min(−)(1)). The use of hypaxial muscles to power active exhalation in the aquatic environment may result from the need for more complete exhalation and larger tidal volumes when breathing infrequently. This hypothesis is supported by previous findings that terrestrial frogs ventilate their lungs with small tidal volumes and exhale passively, whereas aquatic frogs and salamanders use large tidal volumes and and exhale actively.

Hypaxial muscle activity during running and breathing in dogs

2002 ◽  
Vol 205 (13) ◽  
pp. 1953-1967 ◽  
Author(s):  
Stephen M. Deban ◽  
David R. Carrier
Keyword(s):  
Muscle Activity ◽  
Respiratory Function ◽  
Lung Ventilation ◽  
Transversus Abdominis ◽  
Trunk Muscles ◽  
Dual Function ◽  
Intercostal Muscle ◽  
Terrestrial Vertebrates ◽  
Axial Muscles ◽  
External Oblique

SUMMARYThe axial muscles of terrestrial vertebrates serve two potentially conflicting functions, locomotion and lung ventilation. To differentiate the locomotor and ventilatory functions of the hypaxial muscles in mammals, we examined the locomotor and ventilatory activity of the trunk muscles of trotting dogs under two conditions: when the ventilatory cycle and the locomotor cycle were coupled and when they were uncoupled. Patterns of muscle-activity entrainment with locomotor and ventilatory events revealed (i)that the internal and external abdominal oblique muscles performed primarily locomotor functions during running yet their activity was entrained to expiration when the dogs were standing, (ii) that the internal and external intercostal, external oblique thoracic and transversus abdominis muscles performed both locomotor and respiratory functions simultaneously, (iii) that the parasternal internal intercostal muscle performed a primarily respiratory function (inspiration) and (iv) that the deep pectoralis and longissimus dorsi muscles performed only locomotor functions and were not active while the dogs were standing still. We conclude that the dual function of many hypaxial muscles may produce functional conflicts during running. The redundancy and complexity of the respiratory musculature as well as the particular pattern of respiratory—locomotor coupling in quadrupedal mammals may circumvent these conflicts or minimize their impact on respiration.

Quantitative Characterization of Fe/Al2O3 Catalysts. Part II: Reduction, Sulfidation, and CO/Hydrogenation Activity

1992 ◽  
Vol 46 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Douglas P. Hoffmann ◽  
Marwan Houalla ◽  
Andrew Proctor ◽  
David M. Hercules
Keyword(s):  
Solid Solution ◽  
Particle Size ◽  
Co Hydrogenation ◽  
Active Phase ◽  
Alumina Support ◽  
Activity Data ◽  
Co Chemisorption ◽  
Hydrogenation Activity ◽  
Sulfided Catalysts ◽  
Two Phases

ESCA, Mössbauer spectroscopy, XRD, and CO chemisorption were used to study the reduction and sulfidation reactions of a series of 1 to 24 wt % Fe/Al2O3 catalysts. The speciation and particle size of the active phase were correlated with CO hydrogenation activity data. Two phases were previously identified in all oxidic catalysts: Fe2O3 and Fe+3 in solid solution with the alumina support. The Fe2O3 phase was found to reduce to Fe0 and sulfide to Fe1- xS. For the reduced and sulfided catalysts, Mössbauer was able to identify two iron species which were detected as a single solid solution species in the oxidic catalysts. The two species were found to differ by their location in the alumina support. One species is incorporated within the alumina matrix [Fe+2(A)] and the other species [Fe+2(B)] is present at the alumina surface. Both ESCA and CO chemisorption indicate that the Fe particle size increases with increasing iron loading. The turnover frequency (TOF) for CO hydrogenation appears to be a function of the extent of reduction and particle size of the metallic iron phase.

A Rotor Position Detection Method of SRM by Measuring Mutually Induced Voltages

2012 ◽  
Vol 462 ◽  
pp. 757-762
Author(s):  
Lin He ◽  
Jie Bai ◽  
He Xu Sun ◽  
Jie Gao
Keyword(s):  
Active Phase ◽  
Sine Wave ◽  
Induced Voltage ◽  
Primary Coil ◽  
Switched Reluctance ◽  
Rotor Position ◽  
Position Detection ◽  
Reluctance Motor ◽  
Inactive Phase ◽  
Two Phases

This paper describes a method of indirect rotor position measuring for sensorless SRM. The principle is based on measuring the mutually induced voltage in the two inactive phase which is adjacent to the energized phase of the SRM. The mutual voltage in the inactive phase, induced due to the current in the active phase, varies with the position of the rotor. In this paper the SRM was seen as a Differential transformer. One phase was chosen as the primary coil of the transformer, and the adjacent two phases were the Secondary coils. The two Secondary coils were connected in anti-series. A sine wave signal was poured to the primary coil and then we measured the mutual-inductance voltage and processed in a microcontroller to estimate the position of the rotor. The feasibility of the method was proved by an experiment of 8/6 pole four-phase switched reluctance motor.

scholarly journals Kyphotic deformity in pott’s spine

2014 ◽  
Vol 2 (4) ◽  
pp. 201-204
Author(s):  
Sushil Poudel
Keyword(s):  
At Risk ◽  
Spinal Tuberculosis ◽  
Active Phase ◽  
Kyphotic Deformity ◽  
Growth Spurt ◽  
Type I ◽  
Type Ii ◽  
Tuberculosis Patients ◽  
Two Phases ◽  
Deformity Progression

Kyphotic deformity is a well-known complication in spinal tuberculosis patients. This deformity, which is seen in 15% of patients treated conservatively, progresses in two phases: Phase I, which includes the changes in the active phase, and Phase II, which includes changes after the disease is cured. Factors influencing deformity progression are severity of the angle before treatment, the level of the lesion, and age of the patient. Adults have an increase less than 30? during the active phase with no additional changes in the healed phase. During the growth spurt of the children, there is worsening of the deformity in 39% (Type I), an improvement in 44% (Type II), and no change in 17% (Type III). Spine-at risk radiologic signs aid in early identification of the children at risk of late progressive deformity. Surgery for preventing deformity must be done earlier rather than later and in patients with severe disease.DOI: http://dx.doi.org/10.3126/jkmc.v2i4.11790Journal of Kathmandu Medical CollegeVol. 2, No. 4, Issue 6, Oct.-Dec., 2013Page: 201-204

scholarly journals Drosophila melanogaster Responses against Entomopathogenic Nematodes: Focus on Hemolymph Clots

Insects ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 62 ◽  
Author(s):  
Alexis Dziedziech ◽  
Sai Shivankar ◽  
Ulrich Theopold
Keyword(s):  
Drosophila Melanogaster ◽  
Entomopathogenic Nematodes ◽  
Coagulation Factor ◽  
Coagulation Factors ◽  
Body Cavity ◽  
Cellular Level ◽  
Primary Phase ◽  
The Body ◽  
Infection Models ◽  
Two Phases

Several insect innate immune mechanisms are activated in response to infection by entomopathogenic nematodes (EPNs). In this review, we focus on the coagulation of hemolymph, which acts to stop bleeding after injury and prevent access of pathogens to the body cavity. After providing a general overview of invertebrate coagulation systems, we discuss recent findings in Drosophila melanogaster which demonstrate that clots protect against EPN infections. Detailed analysis at the cellular level provided insight into the kinetics of the secretion of Drosophila coagulation factors, including non-classical modes of secretion. Roughly, clot formation can be divided into a primary phase in which crosslinking of clot components depends on the activity of Drosophila transglutaminase and a secondary, phenoloxidase (PO)-dependent phase, characterized by further hardening and melanization of the clot matrix. These two phases appear to play distinct roles in two commonly used EPN infection models, namely Heterorhabditis bacteriophora and Steinernema carpocapsae. Finally, we discuss the implications of the coevolution between parasites such as EPNs and their hosts for the dynamics of coagulation factor evolution.

scholarly journals Mechanics of lung ventilation in a larval salamander Ambystoma tigrinum.

1998 ◽  
Vol 201 (20) ◽  
pp. 2891-2901 ◽  
Author(s):  
EL Brainerd
Keyword(s):  
Buccal Cavity ◽  
Lung Ventilation ◽  
Ambystoma Tigrinum ◽  
Pressure Measurements ◽  
Primitive Character ◽  
X Ray ◽  
Tiger Salamanders ◽  
Transverse Abdominis ◽  
External Oblique ◽  
Internal Oblique

The larval stage of the tiger salamander Ambystoma tigrinum is entirely aquatic, but the larvae rely on their lungs for a large proportion of their oxygen uptake. X-ray video and pressure measurements from the buccal and body cavities demonstrate that the larvae inspire using a two-stroke buccal pump and exhale actively by contracting the hypaxial musculature to increase body pressure. Larvae begin a breath by expanding the buccal cavity to draw in air through the mouth, while simultaneously exhaling air from the lungs to mix with the fresh air in the buccal cavity. The mouth then closes, and the buccal cavity compresses to pump a portion of the mixture into the lungs. The remaining air in the buccal cavity is then released as bubbles from the mouth and gill slits. Ventilatory volumes estimated from X-ray video records indicate that approximately 80 % of the air pumped into the lungs is fresh air and 20 % is previously expired air. Exhalation in larval tiger salamanders is active, powered by contraction of all four layers of lateral hypaxial musculature. Electromyography indicates that the transverse abdominis (TA) muscle is active for the longest duration and shows the highest-amplitude activity, but the external oblique superficialis, the external oblique profundus and the internal oblique also show consistent, low-level activity. The finding that the TA muscle is active during exhalation in larval tiger salamanders contributes to a growing body of evidence that the use of the TA for exhalation is a primitive character for tetrapods.

scholarly journals Automatic Working Phase Picker for Domestic load from Three phase supply

2020 ◽  
Vol 9 (2) ◽  
pp. 973-975
Keyword(s):  
Phase 1 ◽  
Active Phase ◽  
Electrical Equipment ◽  
Routine Work ◽  
Three Phase ◽  
Two Phases ◽  
Phase Number ◽  
At Home

Absence of phase is a very common and serious problem in every sector, at home or workplace. Many times, one or two phases in three phase supply cannot be live. Regardless of this, certain electrical equipment in one room and OFF in another room would be on, several times. This causes considerable disturbance to our routine work. This paper is intended to test the availability of any live phase, and will only link the load to the specific live phase. There is only one phase available, and then the load will still be ON. The idea is conceived with ARDUINO. This controller continually checks the live state of all connected phases, using a Relay the load is connected to active phase by controller. Transistor is operated the relay.When two or more phases are active but load is only connected to phase 1,that active phase number is display in LCD for observation.

MANAGEMENT OF LATENT TO ACTIVE PERIOD ON DELIVERY ADVANCEMENT

2017 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
DINI KURNIAWATI
Keyword(s):  
Caesarean Section ◽  
Postpartum Hemorrhage ◽  
Active Phase ◽  
Active Period ◽  
Management Intervention ◽  
Two Phases ◽  
Latent Phase ◽  
First Stage Of Labor

The first stage of labor to the complete dilatation of the cervix consists of two phases , latent (dilatation 1 cm to 3 cm) and active phases ( 4 cm to 10 cm). Latent phase has a longer duration of the active phase, so more obstetric interventions than those admitted in the this phase. Intervention and duration of the latent phase will cause discomfort and anxiety in the mother during this phase of waiting for progress. Increasing the number of interventions at this phase can be caused by a diagnosis or assessment is less precise and cause complications. Complications in this phase causes of postpartum hemorrhage, chorioamnionitis, and neonatal risk. Interventions at latent phase include oxytocin, amniotic rupture membranes (amniotomy). Woman with prolonged latent phase intervention such as caesarean section (SC). In this phase is need management intervention to reduce the discomfort.Key Word : latent phase, active phase, intervention management, labor

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