THE CAPSULE AND ITS RELATION TO THE EMBRYOGENESIS OF THE ICHNEUMONID PARASITOID MESOLEIUS TENTHREDINIS MORL. IN THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HTG.) (HYMENOPTERA:TENTHREDINIDAE)

1960 ◽  
Vol 38 (4) ◽  
pp. 769-775 ◽  
Author(s):  
Joan F. Bronskill
Keyword(s):  
British Columbia ◽  
Blood Cells ◽  
Oxygen Supply ◽  
Outer Region ◽  
Germ Band ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Histochemical Tests ◽  
Inner Region ◽  
Host Blood

Eggs of the parasitoid Mesoleius tenthredinis Morl. from British Columbia develop and hatch in approximately 120 hours when reared at 23 ± 0.5 °C and a relative humidity of 72 ± 2% within field-collected larch sawfly (Pristiphora erichsonii (Htg.)) larvae from British Columbia and Newfoundland, and within laboratory-reared P. crichsonii larvae from British Columbia. However, they develop normally for only 70 to 80 hours within field-collected larvae from Manitoba as encapsulation of the developing eggs occurs and development ceases in the late germ band stage. The capsule is formed by an accumulation of host blood cells. During the formation of the capsule the innermost blood cells become flattened, fibrous, and enucleated, and eventually form a mass of concentric sheaths of non-cellular material. Thus, the definitive capsule is both cellular (outer region) and non-cellular (inner region). Histochemical tests indicate the presence of mucopolysaccharide in the capsule. It is suggested that the capsule inhibits the embryonic development of the parasitoid by interfering with its oxygen supply.

The structure and composition of the capsule of Trichinella spiralis in host muscle

Parasitology ◽  
1970 ◽  
Vol 60 (2) ◽  
pp. 223-227 ◽  
Author(s):  
R. G. Bruce
Keyword(s):  
Cell Walls ◽  
Trichinella Spiralis ◽  
Outer Region ◽  
Capsule Wall ◽  
Late Professor ◽  
Ultrastructural Studies ◽  
University Of Cambridge ◽  
The Matrix ◽  
Histochemical Tests ◽  
Inner Region

SUMMARYThe results of ultrastructural studies and histochemical tests on the capsule of Trichinella spiralis are given. The capsule wall is shown to consist of two layers, an outer region of tightly compacted fibrils and an inner region of fibrils dispersed through matrix cytoplasm. Histochemical tests show the capsule wall to consist mainly of collagen and cystine. The appearance of the matrix, which is packed with mitochondria, rough endoplasmic reticulum, smooth reticulum and Golgi complexes, together with the histochemical reaction to the five enzymes tested, strongly suggests that the matrix is a region of high metabolic activity. Although there are several very large nuclei in the matrix there is no evidence of cell walls; consequently the matrix is a syncytium.I wish to thank the A.R.C. for financial support while this work was carried out. I should also like to thank Dr D. L. Lee for his advice on many occasions and the late Professor Boyd of the Anatomy Department, University of Cambridge, for the use of the electron microscope in that Department.

THE NATURAL IMMUNITY OF THE LARCH SAWFLY (PRISTIPHORA ERICHSONII (HTG.)) TO THE INTRODUCED PARASITE MESOLEIUS TENTHREDINIS MORLEY, IN MANITOBA AND SASKATCHEWAN

1953 ◽  
Vol 31 (4) ◽  
pp. 313-332 ◽  
Author(s):  
J. A. Muldrew
Keyword(s):  
British Columbia ◽  
Embryonic Development ◽  
Incubation Period ◽  
Natural Immunity ◽  
Sawfly Larvae ◽  
Ringer’S Solution ◽  
Pristiphora Erichsonii ◽  
Effective Inhibition ◽  
Larch Sawfly ◽  
Immunity Reaction

By 1945 it was suspected that the larch sawfly in Saskatchewan and Manitoba had developed an immunity to the introduced parasite Mesoleius tenthredinis Morley. Results of subsequent studies showed that embryonic development of M. tenthredinis in sawfly larvae from Manitoba and Saskatchewan was inhibited three to four days after oviposition. No such inhibition occurred in larvae from British Columbia where the parasite is still highly effective. Inhibition seemed to be related to the deposition of phagocytic capsules around parasite embryos, which occurred in host larvae from Manitoba and Saskatchewan but not in larvae from British Columbia. Encapsulated parasite embryos were shown to be viable, for a number of them hatched after being placed in Ringer's solution. Viability decreased with age. Some embryos were viable seven months after oviposition, though the normal incubation period is 7 to 10 days. Unencapsulated embryos developed more rapidly than encapsulated embryos in Ringer's solution. Results obtained indicate that the phagocytes of the larch sawfly from Manitoba and Saskatchewan play an important role in the immunity reaction of this insect to M. tenthredinis.

Pristiphora erichsonii. [Distribution map].

1959 ◽  
Author(s):  
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
Distribution Map ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Pristiphora erichsonii (Htg.) (Hymenopt., Tenthredinoidea) (Larch Sawfly). Hosts: Larix spp. Information is given on the geographical distribution in EUROPE (excl. USSR), Austria, Britain, Czechoslovakia, Denmark, Finland, France, Germany, Ireland, Netherlands, Norway, Poland, Rumania, Sweden, ASIA (excl. USSR), Japan, USSR, NORTH AMERICA, Canada, U.S.A.

The Effects of Oxygen Supply, Epinephrine, and Acetylcholine on the Distribution of Blood Flow in Trout Gills

1979 ◽  
Vol 83 (1) ◽  
pp. 31-39 ◽  
Author(s):  
JOHN H. BOOTH
Keyword(s):  
Blood Flow ◽  
Liquid Nitrogen ◽  
Blood Cells ◽  
Adrenergic Receptors ◽  
Oxygen Supply ◽  
Central Compartment ◽  
Rapid Freezing ◽  
Saturated Water ◽  
Secondary Lamellae ◽  
Ventral Aorta

Injecting vitally stained blood cells into the ventral aorta of unrestrained, cannulated fish, and rapid freezing in liquid nitrogen, permitted the examination of the effects of oxygen supply, epinephrine and acetylcholine on branchial lamellar perfusion. Compared to the conditions in resting fish in air-saturated water, hypoxia and injection of epinephrine significantly increased the proportion of secondary lamellae receiving stained cells, and acetylcholine caused a significant reduction, but hyperoxia did not significantly affect the proportion of lamellae containing stained cells. Perfusion of the filamental central compartment was not affected by the treatments. It is concluded that trout can respond to changes in oxygen supply by varying the number of secondary lamellae perfused with blood, and that the distribution of blood flow is regulated by cholinergic and adrenergic receptors. It is suggested, however, that lamellar recruitment would not be useful in minimizing the costs of osmo- and iono-regulation.

scholarly journals PROSPECTS FOR TREATMENT AND LIFE-SAVING FOR PATIENTS WITH CORONAVIRUS INFECTION

2020 ◽  
Vol 5 (7(76)) ◽  
pp. 44-51
Author(s):  
Alexander Alexeyevich Medenkov ◽  
Vitaly Nikolayevich Frantsuzov ◽  
Mikhail Vyacheslavovich Dvornikov
Keyword(s):  
Gas Exchange ◽  
Medical Practice ◽  
Blood Cells ◽  
Oxygen Supply ◽  
Blood Substitute ◽  
Symptomatic Treatment ◽  
Analysis Of Means ◽  
Life Saving ◽  
History Of ◽  
Coronavirus Infection

The article is devoted to the analysis of means of symptomatic treatment of coronavirus infection. Pathogenesis and symptoms of damage to organs and systems are considered. The main mechanisms of disruption of blood supply to organs and tissues are noted. The history of the development and use of perfluorane in disorders of gas exchange in the lungs and the function of red blood cells to transport oxygen is presented. Data on the effectiveness of the use of blood substitute in medical practice is considered. The properties and qualities of perfluorane and the mechanisms of its action to improve the oxygen supply of organs and tissues are considered. Evidence of the use of perfluorane in various diseases is given. The prospect of using perfluorane for the treatment of patients with coronavirus infection has been shown.

Estimation of Parasitism of Larch Sawfly Cocoons by Bessa harveyi Tnsd. in Survey Collections

1959 ◽  
Vol 91 (8) ◽  
pp. 496-500 ◽  
Author(s):  
W. G. H. Ives ◽  
R. M. Prentice
Keyword(s):  
Forest Insect ◽  
Small Areas ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Insect Survey ◽  
Forest Biology ◽  
Biology Laboratory ◽  
Total Parasitism

The Forest Insect Survey at the Forest Biology Laboratory, Winnipeg, has been compiling records for a number of years on the percentage of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), parasitized by the tachinid Bessa harveyi Tnsd. Sawfly cocoons were collected each fall from the soil in infested stands, and those containing living larvae were dissected to determine the percentage of parasitism by B. harveyi. These estimates have been used to provide an index of parasitism (Lejeune and Hildahl, 1954), but are of limited value for a number of reasons: (1) estimates can be expressed only as percentage of sound cocoons parasitized; (2) total parasitism cannot be estimated because a portion of the parasites emerge from the cocoons before collection; and (3) estimates of parasitism may not be representative of the stand because there is a tendency to collect cocoons where they are easiest to find; hence all the cocoons in a collection may be from one or two small areas. If the proportion of cocoons containing B. harveyi varies within a stand such collections may give unreliable estimates of parasitism.

History of the Larch Sawfly, with Notes on Origin and Biology,

1955 ◽  
Vol 87 (3) ◽  
pp. 103-111 ◽  
Author(s):  
H. C. Coppel ◽  
K. Leius
Keyword(s):  
British Columbia ◽  
North America ◽  
Native Species ◽  
Insect Pest ◽  
Forest Insect ◽  
Larch Sawfly ◽  
History Of ◽  
Biological Characters ◽  
The Difference ◽  
Forest Biology

The larch sawfly, Pristiphora erichronii (Htg.), is currently considered a major forest insect pest in Canada. At the present time within Canada, the sawfly reacts to parasitism by Mesoleius tenthredinis Morley in two ways. In Manitoba and Saslratchewan the sawfly encapsulates approximately 100 per cent of the parasite eggs deposited, whereas in British Columbia encapsulation rarely exceeds four per cent (Muldrew, 1953). The reasons for the difference in degree of encapsulation are apparently unknown; however, since the origin of the sawfly itself is obscure, the possibility exists that a native species, an introduced species, Or a combination of both may he present, or that geographical or ecological units may have arisen. Studies now under way by officers of the Forest Biology and Entomology divisions are attacking the problem of identity and origin following the pattern established for the European spruce sawfly, Diprion hercyniae (Htg.). In this instance, as with the larch sawfly, parasites were introduced on the assumption that the pest had been introduced from Europe. Critical investigations by Reeks (1941) and Balch, Reeks, and Smith (1941), involving morphological, cytological, and other biological characters, showed that the species occurring in North America was one of two species common in Europe, and previously referred to there as Gilpinia polytoma (Htg.). Balch et al. (1941) showed that D. hercyniae had been introduced into North America.

Measurement and Analysis of Buoyancy-Induced Heat Transfer in Aero-Engine Compressor Rotors

2020 ◽  
Author(s):  
Richard W. Jackson ◽  
Dario Luberti ◽  
Hui Tang ◽  
Oliver J. Pountney ◽  
James A. Scobie ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Outer Region ◽  
Conjugate Problem ◽  
Radial Temperature ◽  
Nusselt Numbers ◽  
Induced Flow ◽  
Aero Engines ◽  
Inner Region ◽  
Buoyancy Induced Flow

Abstract The flow inside cavities between co-rotating compressor discs of aero-engines is driven by buoyancy, with Grashof numbers exceeding 1013. This phenomenon creates a conjugate problem: the Nusselt numbers depend on the radial temperature distribution of the discs, and the disc temperatures depend on the Nusselt numbers. Furthermore, Coriolis forces in the rotating fluid generate cyclonic and anti-cyclonic circulations inside the cavity. Such flows are three-dimensional, unsteady and unstable, and it is a challenge to compute and measure the heat transfer from the discs to the axial throughflow in the compressor. In this paper, Nusselt numbers are experimentally determined from measurements of steady-state temperatures on the surfaces of both discs in a rotating cavity of the Bath Compressor-Cavity Rig. The data are collected over a range of engine-representative parameters and are the first results from a new experimental facility specifically designed to investigate buoyancy-induced flow. The radial distributions of disc temperature were collected under carefully-controlled thermal boundary conditions appropriate for analysis using a Bayesian model combined with the equations for a circular fin. The Owen-Tang buoyancy model has been used to compare predicted radial distributions of disc temperatures and Nusselt numbers with some of the experimentally determined values, taking account of radiation between the interior surfaces of the cavity. The experiments show that the average Nusselt numbers on the disc increase as the buoyancy forces increase. At high rotational speeds the temperature rise in the core, created by compressibility effects in the air, attenuates the heat transfer and there is a critical rotational Reynolds number for which the Nusselt number is a maximum. In the cavity, there is an inner region dominated by forced convection and an outer region dominated by buoyancy-induced flow. The inner region is a mixing region, in which entrained cold throughflow encounters hot flow from the Ekman layers on the discs. Consequently, the Nusselt numbers on the downstream disc in the inner region tend to be higher than those on the upstream disc.

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