Descriptions of spawning of the pouched lamprey (Geotria australis) in tanks and of morphological changes leading up to and following spawning

2020 ◽  
Vol 26 (3) ◽  
pp. 301 ◽  
Author(s):  
K. R. Paton ◽  
M. H. Cake ◽  
D. J. Bird ◽  
I. C. Potter

The anadromous Geotria australis, one of only three lamprey species representing the early agnathan (jawless) stage of vertebrate evolution in Australia and New Zealand, is declining in abundance. Its adults were caught soon after they had entered rivers on their non-trophic upstream migration and maintained in laboratory tanks for 13–15 months through to spawning. As adult G. australis are susceptible to haemorrhagic septicaemia, they were treated prophylactically and maintained in 3-m3 aquaria supplied with a flow-through charcoal filtration system and UV steriliser. Air temperature and the light:dark regime were constantly adjusted to parallel those in the environment. Males developed the very large suctorial disc and gular pouch characteristic of maturity and both sexes matured at the same time as in the wild. While males frequently showed aggressive behaviour towards each other, the same male and female mated on several occasions. The male coiled around the female and, with his urogenital papilla close to the female’s cloaca, twisted and vibrated, leading to egg release. These eggs formed coagulated clusters as in the wild, with many progressing through to the eight-cell stage. Remarkably, numerous G. australis were still alive 95–392 days after the end of the short spawning period, and one male after a further 119 days. Postspawning survival would be facilitated inter alia by extensive proteolysis, reflected in a shortening of the body. The data in this paper emphasise that G. australis is a highly atypical lamprey and provides invaluable information for conserving this declining species.

2020 ◽  
pp. 14-17
Author(s):  
Irina A. Shkuratova ◽  
◽  
Lyudmila I. Drozdova ◽  
Aleksander I. Belousov ◽  

Mycotoxicological monitoring of forages shows that the problem of mycotoxicosis has been relevant for several decades. Minimal doses of mycotoxins in feed lead to a decrease in milk productivity, increased sensitivity to infectious and non-infectious diseases. When several mycotoxins enter the body simultaneously, a synergistic effect develops, causing a significant increase in toxicity. Feed contaminated with several types of fungi and their toxins is dangerous for dairy cattle. It was found that the feed mixture contained the types of associations of Aspergillus spp. fungi + Fusarium; Aspergillus spp. + Penicillium spp. + Mucor spp; Fusarium + Penicillium; Mucor spp. + Fusarium + Ustilaginales. Pathogenetic features of metabolic and morphological changes in highly productive cows with polymycotoxicosis were studied. Feeding food contaminated with various metabolites of mold fungi leads to the development of signs of chronic toxemia in animals. Clinical manifestations are the development of diarrhea and dehydration, with a decrease in milk productivity. Metabolic disorders feature the development of an inflammatory process, metabolic acidosis, hyperfermentonemia, with an increase in the amount of creatinine and urea in the blood serum. Metabolic signs indicate the development of hepatorenal syndrome due to structural disorders of the liver and kidneys. Histological signs of polymicotoxicosis are intracapillary and hemorrhagic glomerulonephritis, hepatocyte micronecrosis, and proliferation of connective tissue stroma cells, which leads to the development of atrophic cirrhosis in the interstitial and circular phases.


Author(s):  
N. I. Maslova

The article presents analysis of material and results of their own studies on changes in the permeability of cellular structures, organs and tissues in carp, which is of great importance in determining age-related indicators. The cells permeability in liver and gonads estimation was carried out under the experimental base of VNIIR on two carp genotypes during the pre-spawning period. The carp groups taken for analysis differed significantly in their genotypes. In females of the Khrapunov group the fecundity was 2023.0 thousand units, while the number of oocytes filled with yolk was only 0.7%, in the Ostashevsky ones - 1370.0 thousand units and 8.6%, respectively. During estimation the chemical composition of the generative tissue in females and males it was established that the cholesterol and lecithin content in males is higher than that of females, while feeding dependence is observed, especially on the amount of protein in the diet. For example, in females on protein diet contained less glycogen in gonads than on females on carbohydrate diet. Lecithin and cholesterol are higher in males than in females, which corresponds to increasing the Gyurdy Ratio (estimation of cell membrane strength). In spermatogenesis the content of phospholipids and cholesterol in the liver was decreased less than during ovogenesis. This indicates a lower level of synthetic processes in the milts compared with the ovaries. The cholesterol content in sperm is higher than in caviar in 19.6 times, and phospholipids almost doubled. With increasing age, the Gyordy Ratio for caviar decreases, for sperm it increases, the percentage of caviar fertilization increases. As the body age metabolism deteriorates, cellular permeability decreases (the ratio of lecithin and cholesterol changes significantly). At the same time, the permeability of cells in different organs and tissues varies and depends on living conditions, especially feeding and to some extent on the origin. In fish the gross productivity decreases as growth slows down and more energy is spent on adaptation to environmental conditions.


Author(s):  
M. S. Bugaeva ◽  
O. I. Bondarev ◽  
N. N. Mikhailova ◽  
L. G. Gorokhova

Introduction. The impact on the body of such factors of the production environment as coal-rock dust and fluorine compounds leads to certain shift s in strict indicators of homeostasis at the system level. Maintaining the relative constancy of the internal environment of the body is provided by the functional consistency of all organs and systems, the leading of which is the liver. Organ repair plays a crucial role in restoring the structure of genetic material and maintaining normal cell viability. When this mechanism is damaged, the compensatory capabilities of the organ are disrupted, homeostasis is disrupted at the cellular and organizational levels, and the development of the main pathological processes is noted.The aim of the study is to compare the morphological mechanisms of maintaining structural homeostasis of the liver in the dynamics of the impact on the body of coal-rock dust and sodium fluoride.Materials and methods. Experimental studies were conducted on adult white male laboratory rats. Features of morphological mechanisms for maintaining structural homeostasis of the liver in the dynamics of exposure to coal-rock dust and sodium fluoride were studied on experimental models of pneumoconiosis and fluoride intoxication. For histological examination in experimental animals, liver sampling was performed after 1, 3, 6, 9, 12 weeks of the experiment.Results. The specificity of morphological changes in the liver depending on the harmful production factor was revealed. It is shown that chronic exposure to coal-rock dust and sodium fluoride is characterized by the development of similar morphological changes in the liver and its vessels from the predominance of the initial compensatory-adaptive to pronounced violations of the stromal and parenchymal components. Long-term inhalation of coal-rock dust at 1–3 weeks of seeding triggers adaptive mechanisms in the liver in the form of increased functional activity of cells, formation of double-core hepatocytes, activation of immunocompetent cells and endotheliocytes, ensuring the preservation of the parenchyma and the general morphostructure of the organ until the 12th week of the experiment. Exposure to sodium fluoride leads to early disruption of liver compensatory mechanisms and the development of dystrophic changes in the parenchyma with the formation of necrosis foci as early as the 6th week of the experiment.Conclusions. The study of mechanisms for compensating the liver structure in conditions of long-term exposure to coal-rock dust and sodium fluoride, as well as processes that indicate their failure, and the timing of their occurrence, is of theoretical and practical importance for developing recommendations for the timely prevention and correction of pathological conditions developing in employees of the aluminum and coal industry.The authors declare no conflict of interests.


1990 ◽  
Vol 70 (2) ◽  
pp. 331-390 ◽  
Author(s):  
J. I. Hoffman ◽  
J. A. Spaan

The blood vessels that run on the surface of the heart and through its muscle are compliant tubes that can be affected by the pressures external to them in at least two ways. If the pressure outside these vessels is higher than the pressure at their downstream ends, the vessels may collapse and become Starling resistors or vascular waterfalls. If this happens, the flow through these vessels depends on their resistance and the pressure drop from their inflow to the pressure around them and is independent of the actual downstream pressure. In the first part of this review, the physics of collapsible tubes is described, and the possible occurrences of vascular waterfalls in the body is evaluated. There is good evidence that waterfall behavior is seen in collateral coronary arteries and in extramural coronary veins, but the evidence that intramural coronary vessels act like vascular waterfalls is inconclusive. There is no doubt that in systole there are high tissue pressures around the intramyocardial vessels, particularly in the subendocardial muscle of the left ventricle. The exact nature and values of the forces that act at the surface of the small intramural vessels, however, are still not known. We are not certain whether radial (compressive) or circumferential and longitudinal (tensile) stresses are the major causes of vascular compression; the role of collagen struts in modifying the reaction of vessel walls to external pressures is unknown but possibly important; direct examination of small subepicardial vessels has failed to show vascular collapse. One of the arguments in favor of intramyocardial vascular waterfalls has been that during a long diastole the flow in the left coronary artery decreases and reaches zero when coronary arterial pressure is still high: it can be as much as 50 mmHg in the autoregulating left coronary arterial bed and approximately 15-20 mmHg even when the vessels have been maximally dilated. These high zero flow pressures, especially during maximal vasodilatation, have been regarded as indicating a high back pressure to flow that is due to waterfall behavior of vessels that are exposed to tissue pressures.(ABSTRACT TRUNCATED AT 400 WORDS)


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tali Leibovich-Raveh ◽  
Ashael Raveh ◽  
Dana Vilker ◽  
Shai Gabay

AbstractWe make magnitude-related decisions every day, for example, to choose the shortest queue at the grocery store. When making such decisions, which magnitudes do we consider? The dominant theory suggests that our focus is on numerical quantity, i.e., the number of items in a set. This theory leads to quantity-focused research suggesting that discriminating quantities is automatic, innate, and is the basis for mathematical abilities in humans. Another theory suggests, instead, that non-numerical magnitudes, such as the total area of the compared items, are usually what humans rely on, and numerical quantity is used only when required. Since wild animals must make quick magnitude-related decisions to eat, seek shelter, survive, and procreate, studying which magnitudes animals spontaneously use in magnitude-related decisions is a good way to study the relative primacy of numerical quantity versus non-numerical magnitudes. We asked whether, in an animal model, the influence of non-numerical magnitudes on performance in a spontaneous magnitude comparison task is modulated by the number of non-numerical magnitudes that positively correlate with numerical quantity. Our animal model was the Archerfish, a fish that, in the wild, hunts insects by shooting a jet of water at them. These fish were trained to shoot water at artificial targets presented on a computer screen above the water tank. We tested the Archerfish's performance in spontaneous, untrained two-choice magnitude decisions. We found that the fish tended to select the group containing larger non-numerical magnitudes and smaller quantities of dots. The fish selected the group containing more dots mostly when the quantity of the dots was positively correlated with all five different non-numerical magnitudes. The current study adds to the body of studies providing direct evidence that in some cases animals’ magnitude-related decisions are more affected by non-numerical magnitudes than by numerical quantity, putting doubt on the claims that numerical quantity perception is the most basic building block of mathematical abilities.


2020 ◽  
Vol 03 (04) ◽  
pp. 69-73
Author(s):  
Samira Mammadhasan Yagubova ◽  
◽  
Elchin Chingiz Akbarov ◽  
Tarana Nadir Mirzayeva ◽  
◽  
...  

During the staphylococcal infection, changes in the interaction of glandular cells, dystrophic and disorganizing pathologies in tissues, especially acute structural and hemodynamic changes in the stroma of the glands in the pituitary-adrenal-thyroid system, develop from the first day of the experiment. At the end of the experiment, on the background of a decrease in exudative processes, fibroplastic reactions are significantly activated, resulting in signs of incomplete regeneration – mainly sclerotic processes and cystic-atrophic changes in the parenchyma. Structural changes in tissues in the early stages of staphylococcal infection and the dynamics of development are characterized by specific symptoms in each of the glands. Since the pituitary gland is exposed to endogenous and exogenous factors earlier and more often than the adrenal glands, and the adrenal glands are earlier than the thyroid gland, dystrophic and destructive changes in the pituitary and adrenal glands are more pronounced at the early stage of the experiment. These morphological changes can change the hormonal status of the body and lead to dysfunction of the endocrine system as a whole – a decrease in the functional activity of the glands to some extent, and even inhibition of adenohypophyseal cells. Key words: staphylococcal infection, peritonitis, pituitary, adrenal and thyroid glands


1930 ◽  
Vol 26 (7) ◽  
pp. 118-124
Author(s):  
S. I. Sherman

Currently, autohemotherapy takes one of the places of honor among; of our therapeutic measures and there is not a single area of ​​practical medicine where oisch is not applied. At the same time, this type of therapy still does not have an exact scientific basis; Thus, there are many different views on the essence of the action of this method, but there are still no precise indications and contraindications for the use of autohemotherapy for certain types of diseases, then the dosage, frequency of injections, their number, etc., vary sharply among different authors. we will review the following issues - the essence of the action of autohemotherapy, the dosage and frequency of injections, the reaction of the body (general, focal, local), the advantage of one or another method of using autoblood injections (intracutaneous, subcutaneous and intramuscular routes of administration) and, finally, morphological changes in blood during this method of treatment.


Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 319-335 ◽  
Author(s):  
M. Jerka-Dziadosz ◽  
N. Garreau de Loubresse ◽  
J. Beisson

kin241 is a monogenic nuclear recessive mutation producing highly pleiotropic effects on cell size and shape, generation time, thermosensitivity, nuclear reorganization and cortical organization. We have analyzed the nature of the cortical disorders and their development during division, using various specific antibodies labelling either one of the cortical cytoskeleton components, as was previously done for analysis of cortical pattern formation in the wild type. Several abnormalities in basal body properties were consistently observed, although with a variable frequency: extra microtubules in either the triplets or in the lumen; nucleation of a second kinetodesmal fiber; abnormal orientation of the newly formed basal body with respect to the mother one. The latter effect seems to account for the major observed cortical disorders (reversal, intercalation of supplementary ciliary rows). The second major effect of the mutation concerns the spatiotemporal map of cortical reorganization during division. Excess basal body proliferation occurs and is correlated with modified boundaries of some of the cortical domains identified in the wild type on the basis of their basal body duplication pattern. This is the first mutant described in a ciliate in which both the structure and duplication of basal bodies and the body plan are affected. The data support the conclusion that the mutation does not alter the nature of the morphogenetic signal(s) which pervade the dividing cell, nor the competence of cytoskeletal structures to respond to signalling, but affects the local interpretation of the signals.


Author(s):  
Ana L. Ibáñez ◽  
Diana Y. Montero

This study documents the presence of crypsis in Mugil curema juveniles under laboratory culture. Initially, the juveniles were located in one brown tank (BT1), later almost half of the individuals were placed in a white tank (WT) where they showed a pigmentation change to white. After being moved to another brown tank (BT2), the juveniles changed to their brown original colour, but kept a few small white spots on the dorsal axis of the body. The ventral head melanophore pattern also changed in the white specimens. Temperature (°C), oxygen (mg l−1) and Illuminance light (Lux m−2), total length (mm) and total weight (g) were determined by tank. Chromaticity was measured in L*(relative luminance) a*(measurement relating to the redness or greenness of the light) b*(measurement relating to the yellowness or blueness of the light) coordinates where all three values are required to completely describe an object’s colour. One-way ANOVA showed no differences for temperature, oxygen and illuminance light among tanks. Length and weight were similar for BT1 and WT but both were different from BT2. The white juveniles depicted similar L* as the WT background as well as the dorsal area of the brown pigmentation and converted juveniles to the brown tanks BT1 and BT2, respectively. Therefore, the fish's body relative luminance matches the background. To our knowledge this behaviour has not been reported before for any fish mullet either cultured or living in the wild.


Author(s):  
Vaibhav K. Arghode ◽  
Pramod Kumar ◽  
Yogendra Joshi ◽  
Thomas S. Weiss ◽  
Gary Meyer

Effective air flow distribution through perforated tiles is required to efficiently cool servers in a raised floor data center. We present detailed computational fluid dynamics (CFD) modeling of air flow through a perforated tile and its entrance to the adjacent server rack. The realistic geometrical details of the perforated tile, as well as of the rack are included in the model. Generally models for air flow through perforated tiles specify a step pressure loss across the tile surface, or porous jump model based on the tile porosity. An improvement to this includes a momentum source specification above the tile to simulate the acceleration of the air flow through the pores, or body force model. In both of these models geometrical details of tile such as pore locations and shapes are not included. More details increase the grid size as well as the computational time. However, the grid refinement can be controlled to achieve balance between the accuracy and computational time. We compared the results from CFD using geometrical resolution with the porous jump and body force model solution as well as with the measured flow field using Particle Image Velocimetry (PIV) experiments. We observe that including tile geometrical details gives better results as compared to elimination of tile geometrical details and specifying physical models across and above the tile surface. A modification to the body force model is also suggested and improved results were achieved.


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