Volume relationships during the pregnancy cycle of the tsetse fly Glossina austeni

1972 ◽  
Vol 50 (7) ◽  
pp. 999-1010 ◽  
Author(s):  
S. S. Tobe ◽  
K. G. Davey
Keyword(s):  
Small Volume ◽  
Tsetse Fly ◽  
Reproductive State ◽  
Volume Changes ◽  
Constant Weight ◽  
Low Level ◽  
Histological Sections ◽  
Glossina Austeni ◽  
A Value ◽  
Air Sacs

Because of their haematophagous and viviparous habits, female Glossina austeni undergo large changes in both volume and weight during each pregnancy cycle. As the developing larva in the uterus increases in size, the volume of the mother also increases. These changes in volume of the adult fly occur almost exclusively in the abdomen, which does not contain significant air sacs with which to buffer the volume changes. The changes in abdominal volume are made possible by an elastic ventral abdominal cuticle which is manifested in histological sections as changes in the thickness of the ventral abdominal cuticle during the pregnancy cycle. Stretching appears to occur in the endocuticle.Female G. austeni tend to feed to a constant weight irrespective of their reproductive state. Before the first ovulation, flies feed to a weight of about 50 mg but subsequently feed to a weight of about 80 mg. This increase coincides with the cessation of postemergence cuticle deposition, as well as ovulation, but it is not known whether these events are functionally related.Haemolymph volume of female G. austeni remains at a low level throughout the observed pregnancy cycles at a value of about 5 μliters. This small volume may impose limitations on the transport of nutrients through the haemolymph. Following feeding, haemolymph volume does not change.

Mechanical impedances of lungs and chest wall in the cat

1992 ◽  
Vol 73 (2) ◽  
pp. 427-433 ◽  
Author(s):  
Z. Hantos ◽  
A. Adamicza ◽  
E. Govaerts ◽  
B. Daroczy
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Small Volume ◽  
Angular Frequency ◽  
Forced Oscillations ◽  
Amplitude Dependence ◽  
Volume Changes ◽  
The Real ◽  
Output Flow ◽  
Frequency Independent

In nine anesthetized and paralyzed cats, the mechanical impedances of the total respiratory system (Zrs) and the lungs (ZL) were measured with small-volume pseudorandom forced oscillations between 0.2 and 20 Hz. ZL was measured after thoracotomy, and chest wall impedance (Zw) was calculated as Zw = Zrs-ZL. All impedances were determined by using input airflow [input impedance (Zi)] and output flow measured with a body box [transfer impedance (Zt)]. The differences between Zi and Zt were small for Zrs and negligible for ZL. At 0.2 Hz, the real and imaginary parts of ZL amounted to 33 +/- 4 and 35 +/- 3% (SD), respectively, of Zrs. Up to 8 Hz, all impedances were consistent with a model containing a frequency-independent resistance and inertance and a constant-phase tissue part (G-jH)/omega alpha, where G and H are coefficients for damping and elastance, respectively, omega is angular frequency, and alpha determines the frequency dependence of the real and imaginary parts. G/H was higher for Zw than for ZL (0.29 +/- 0.05 vs. 0.22 +/- 0.04, P less than 0.01). In four cats, the amplitude dependence of impedances was studied: between oscillation volumes of 0.8 and 3 ml, GL, HL, Gw, and Hw decreased on average by 3, 9, 26, and 29%, respectively, whereas the change in G/H was small for both ZL (7%) and Zw (-4%). The values of H were two to three times higher than the quasistatic elastances estimated with greater volume changes (greater than 20 ml).

scholarly journals The control of diuresis in the tsetse fly Glossina austeni: a preliminary investigation of the diuretic hormone

1975 ◽  
Vol 63 (2) ◽  
pp. 391-401
Author(s):  
J. D. Gee
Keyword(s):  
Sialic Acid ◽  
Nervous Tissue ◽  
Preliminary Investigation ◽  
Tsetse Fly ◽  
Malpighian Tubules ◽  
Diuretic Hormone ◽  
Glossina Austeni ◽  
Heat Stable ◽  
Soluble Molecule ◽  
Degradative Enzyme

The rate of secretion of the Malpighian tubules of Glossina austeni is controlled by a diuretic hormone. This hormone is present in the nervous tissue of the fly together with a degradative enzyme that can be activated by boiling. It is demonstrated that the Malpighian tubules are able to destroy the diuretic hormone; they may therefore participate in the control of diuresis. The diuretic hormone appears to be a heat-stable, non-dialysable, alcohol-soluble molecule, containing amino acid, glucose and sialic acid residues.

scholarly journals Temporary prosthetic fitting for below-knee amputation

1989 ◽  
Vol 13 (2) ◽  
pp. 86-89 ◽  
Author(s):  
H. Ozyalcin ◽  
E. Sesli
Keyword(s):  
Developing Countries ◽  
Small Volume ◽  
High Pressures ◽  
Knee Prosthesis ◽  
High Price ◽  
Volume Changes ◽  
Dressing Method ◽  
Knee Amputation ◽  
Long Period ◽  
Prosthetic Fitting

The problems encountered in fitting and using the permanent below-knee prosthesis in developing countries are the high price of the prosthesis, inadequate fitting and lack of proper rehabilitation. In Turkey, the preferred treatment of the stump post-operatively is by the soft dressing method with bandaging for maturation and shrinkage. Generally, the application of the permanent prosthesis is in the sixth month post-operatively. Since in patellar-tendon-bearing (PTB) sockets, stumps have to withstand high pressures in limited areas, the PTB socket can only tolerate small volume changes in the stump. For this reason bandaging over a long period may be insufficient for adequate stump shrinkage and amputees will need another below-knee prosthesis, which most of them cannot afford after only a few weeks use. In the authors' clinic, 19 amputees were fitted with simple, effective and inexpensive temporary prostheses following either conventional immediate post-operative dressing or the soft dressing method. The temporary prosthesis is worn for two months. It produces fast stump shrinkage, helps maturation and permits ambulatory discharge even in bilateral amputees. For economical reasons, only eight of nineteen patients were fitted with permanent prostheses, all wearing them successfully without the necessity of further rehabilitation.

Use of Enterobacteriaceae Analysis Results for Predicting Absence of Salmonella Serovars on Beef Carcasses

2009 ◽  
Vol 72 (2) ◽  
pp. 260-266 ◽  
Author(s):  
JOHN R. RUBY ◽  
STEVEN C. INGHAM
Keyword(s):  
Small Volume ◽  
Large Data ◽  
Data Sets ◽  
Data Set ◽  
A Value ◽  
Large Data Set ◽  
Intervention Treatment ◽  
Beef Carcasses ◽  
Predictive Approach ◽  
Potential Use

Previous work using a large data set (no. 1, n = 5,355) of carcass sponge samples from three large-volume beef abattoirs highlighted the potential use of binary (present or absent) Enterobacteriaceae results for predicting the absence of Salmonella on carcasses. Specifically, the absence of Enterobacteriaceae was associated with the absence of Salmonella. We tested the accuracy of this predictive approach by using another large data set (no. 2, n = 2,163 carcasses sampled before or after interventions) from the same three data set no. 1 abattoirs over a later 7-month period. Similarly, the predictive approach was tested on smaller subsets from data set no. 2 (n = 1,087, and n = 405) and on a much smaller data set (no. 3, n = 100 postintervention carcasses) collected at a small-volume abattoir over 4 months. Of Enterobacteriaceae-negative data set no. 2 carcasses, >98% were Salmonella negative. Similarly accurate predictions were obtained in the two data subsets obtained from data set no. 2 and in data set no. 3. Of final postintervention carcass samples in data set nos. 2 and 3, 9 and 70%, respectively, were Enterobacteriaceae positive; mean Enterobacteriaceae values for the two data sets were −0.375, and 0.169 log CFU/100 cm2 (detection limit = −0.204, and Enterobacteriaceae negative assigned a value of −0.505 log CFU/100 cm2). Salmonella contamination rates for final postintervention beef carcasses in data set nos. 2 and 3 were 1.1 and 7.0%, respectively. Binary Enterobacteriaceae results may be useful in evaluating beef abattoir hygiene and intervention treatment efficacy.

Aircraft Applications of Insecticides in East Africa. II.—An experimental Attempt to Produce a Fly-free Corridor through a Belt of Tsetse-infested Woodland

1953 ◽  
Vol 44 (3) ◽  
pp. 601-609 ◽  
Author(s):  
K. S. Hocking ◽  
H. C. M. Parr ◽  
D. Yeo ◽  
P. A. Robins
Keyword(s):  
East Africa ◽  
Wind Direction ◽  
Tsetse Fly ◽  
Low Level ◽  
Median Diameter ◽  
Savannah Woodland ◽  
Mass Median ◽  
Mass Median Diameter

An experimental attempt was made to produce a fly-free corridor through a belt of savannah woodland containing the tsetse fly G. swynnertoni.An area two miles wide and four miles long was treated with a coarse spray of a 4·6 per cent, w/v solution of DDT in Shell Diesoline. The dosage per application was 0·5 gallons per acre, and seven applications were made, at intervals of approximately two weeks, so that the treatment covered two pupal periods.The fly density had fallen to a very low level by the end of the experiment, and the area remained virtually free from flies for the subsequent two months. An examination of the data suggests, however, that the fly population was maintained largely by immigrant flies, and was certainly subject to wide variations, and it seems certain that the effect of the applications would have been considerably less upon a stable, self-supporting population.The drop spectrum of the ground deposit had a mass median diameter of 0·35 mm., and the recovery of insecticide in the area was approximately 60 per cent. Leeward and under sides of obstacles did not receive a dose although in some cases dosages were obtained on apparently leeward sides, probably because of local reversals of wind direction.

scholarly journals Synchrotron imaging of the grasshopper tracheal system: morphological and physiological components of tracheal hypermetry

2009 ◽  
Vol 297 (5) ◽  
pp. R1343-R1350 ◽  
Author(s):  
Kendra J. Greenlee ◽  
Joanna R. Henry ◽  
Scott D. Kirkton ◽  
Mark W. Westneat ◽  
Kamel Fezzaa ◽  
...  
Keyword(s):  
Late Stage ◽  
Early Stage ◽  
Tissue Growth ◽  
Whole Body ◽  
Body Volume ◽  
Volume Changes ◽  
Tracheal System ◽  
Body Regions ◽  
Air Sacs ◽  
Synchrotron Imaging

As grasshoppers increase in size during ontogeny, they have mass specifically greater whole body tracheal and tidal volumes and ventilation than predicted by an isometric relationship with body mass and body volume. However, the morphological and physiological bases to this respiratory hypermetry are unknown. In this study, we use synchrotron imaging to demonstrate that tracheal hypermetry in developing grasshoppers ( Schistocerca americana) is due to increases in air sacs and tracheae and occurs in all three body segments, providing evidence against the hypothesis that hypermetry is due to gaining flight ability. We also assessed the scaling of air sac structure and function by assessing volume changes of focal abdominal air sacs. Ventilatory frequencies increased in larger animals during hypoxia (5% O2) but did not scale in normoxia. For grasshoppers in normoxia, inflated and deflated air sac volumes and ventilation scaled hypermetrically. During hypoxia (5% O2), many grasshoppers compressed air sacs nearly completely regardless of body size, and air sac volumes scaled isometrically. Together, these results demonstrate that whole body tracheal hypermetry and enhanced ventilation in larger/older grasshoppers are primarily due to proportionally larger air sacs and higher ventilation frequencies in larger animals during hypoxia. Prior studies showed reduced whole body tracheal volumes and tidal volume in late-stage grasshoppers, suggesting that tissue growth compresses air sacs. In contrast, we found that inflated volumes, percent volume changes, and ventilation were identical in abdominal air sacs of late-stage fifth instar and early-stage animals, suggesting that decreasing volume of the tracheal system later in the instar occurs in other body regions that have harder exoskeleton.

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