scholarly journals Optimización del tratamiento térmico para la inducción al desove de Argopecten purpuratus (Mollusca: Bivalvia)

2021 ◽  
Vol 56 (2) ◽  
pp. 145-150
Author(s):  
Jhon Dionicio-Acedo ◽  
Alison Cabrera-Simon ◽  
Maryandrea Rosado-Salazar ◽  
Arturo Aguirre-Velarde

Based on methodologies currently used in commercial hatcheries, four thermic treatments were compared to induce the gametes expulsion of Argopecten purpuratus. The treatments evaluated included: 1) gradual increase in temperature, 2) gradual decrease, 3) 5 °C thermal-shock, 4) 10 °C thermal-shock and 5) control at constant temperature 16 °C. After induction, the number of fertilized oocytes in each treatment was estimated. The results show that a gradual increase in temperature between 16 and 26 °C causes a significantly higher proportion of fertilized oocytes compared to other treatments.

2021 ◽  
Vol 9 (1) ◽  
pp. 44-54
Author(s):  
V.I. Trykhlib ◽  
T.I. Lysenko ◽  
A.O. Yeroshenko ◽  
О.S. Martynchuk ◽  
K.P. Bieliaieva ◽  
...  

The article provides a review of the literature on the effectiveness of glucocorticoids in viral infections, including the new coronavirus infection COVID-19. The results of our research of the dynamics of laboratory parameters in patients who recovered and those who died are presented. The average age of patients who received 8 mg of dexamethasone and recovered was less than that of the deceased. The average day on which the patients were hospitalized in the ICU and who received 8 mg of dexamethasone in both groups was the same (on average on day 7). It is noteworthy that in patients who recovered, the febrile temperature was more often recorded before hospitalization, while in those who died it was more often subfebrile. The temperature during hospitalization in all categories of patients was on average at subfebrile numbers. The respiratory rate on admission in all categories of patients did not differ significantly and on average was about 19/min (up to 20/min was in 50 % of patients who recovered and 58.3 % of those who died). Those who recovered were more likely to have a normal heart rate on admission, but tachycardia was less common than within those who died. In patients who subsequently died, lower saturation levels were more often recorded upon admission. In the first 3 days after hospitalization, in patients who recovered and received 8 mg of dexamethasone, leukocytosis and granulocytosis were recorded more often; there was an increased number of stab neutrophils and the number of patients with it. The patients who subsequently died more often developed leukopenia, more pronounced lymphopenia with an increased quantity of patients with it; they presented more pronounced thrombocytopenia (the number of patients with it did not differ from those who recovered), higher erythrocyte sedation rate. In patients who subsequently died, during the observation period, there was a gradual increase in the number of leukocytes, but a gradual decrease in the number of lymphocytes, the creatine phosphokinase level increased from the 7th–9th days of hospitalization; on days 4–6 of hospitalization, the lactate dehydrogenase level significantly increased with its subsequent decline to a level that was greater than this in patients who recovered. Initially. The patients who recovered had an increase in leukocytes with their subsequent gradual decrease, a gradual increase in the level of lymphocytes, a decrease in the level of creatine phosphokinase, lactate dehydrogenase. In all categories of patients, a gradual decrease in the number of stab neutrophils was observed over time, a gradual increase in the number of platelets was also observed over time, but in those who recovered their level was slightly higher; in both groups, an increase in the urea level was observed over time, but in those who died its level from day 7 and later was significantly higher than in those who recovered; in patients in both groups, an increase in the level of creatinine was observed over time, but in those who died, its level from day 7 and later was significantly higher than in those who recovered; both groups showed a decrease in C-reactive protein over time, but those who died from the very beginning of their hospital stay and during all follow-up periods had higher levels than those who recovered.


1982 ◽  
Vol 72 (3) ◽  
pp. 941-958
Author(s):  
J. Enrique Luco

abstract The variation with distance of the values of local magnitude, ML, obtained from strong-motion records at short distances to the sources is examined. The available data seem to indicate a gradual decrease with distance from the fault up to a distance of about 20 km followed by a gradual increase for distances in the range from 20 to 100 km. This type of distance dependence can be predicted on the basis of available correlations of peak Wood-Anderson seismograph response with peak velocity and of peak velocity with distance to the fault and local magnitude obtained from actual Wood-Anderson records. These correlations are employed to obtain an alternative relation between local magnitude, synthesized peak Wood-Anderson response and distance to the fault. The alternative relation which is valid only at short distances to the fault gives good agreement with the available data and seems to indicate a degree of saturation of the Wood-Anderson response at short distances. The average estimates of ML based on this alternative relation for several well-recorded events are similar to those obtained on the basis of Richter's standard definition. The alternative estimates have the advantage of removing the distance dependence exhibited by the standard estimates. The effects that this modification of the relation between local magnitude, peak Wood-Anderson response, and distance has on certain estimates of peak strong-motion amplitudes are also examined.


1933 ◽  
Vol 58 (4) ◽  
pp. 401-414 ◽  
Author(s):  
Raymond C. Parker

1. Races of fibroblasts that are functionally distinct have been isolated from the various tissues and organs of a single chick embryo. 2. Functionally distinct races of fibroblasts have also been isolated from corresponding parts of embryos of different ages. 3. Under the conditions of the experiments, and for the particular races of fibroblasts that have been studied, it has not been possible to demonstrate a gradual decrease, or a gradual increase, in the rate of multiplication of fibroblasts obtained from corresponding parts of embryos of gradually increasing ages. 4. Experiments made on strains of fibroblasts derived from the mesonephros and metanephros of a 16 day chick embryo have indicated that the rate of multiplication of these cells in a given medium reflects the physiological state, at the moment of isolation, of the particular part of the embryo from which they are obtained. 5. The rate of multiplication of a given race of fibroblasts in a particular medium does not serve, necessarily, as an index of the age of the individual from which the race is derived. 6. The functional differences that distinguish the various races of fibroblasts are permanent; they are retained by the cells from passage to passage indefinitely, despite such attempts as have thus far been made to change them.


1975 ◽  
Vol 21 (5) ◽  
pp. 675-681 ◽  
Author(s):  
Thomas L. McDonald ◽  
L. P. Mallavia

A host response to infection by Coxiella burneti was investigated. Infected yolk sacs were harvested from embryonated eggs and assayed for glycolytic activity. Assays of glycolytic enzymes included glucose isomerase, aldolase, phosphofructokinase, fructose-1,6-diphosphatase, glyceraldehyde-3-phosphate dehydrogenase, enolase, and pyruvate kinase. No significant differences in enzymatic activity between normal and infected tissues through the 12th day were observed. From the 13th day through the 16th day, the glycolytic activity of normal tissues decreased. Glycolytic activity of infected tissues did not decrease, but showed a gradual increase during this same time period. Embryos from infected eggs demonstrated a gradual decrease in total weight from the 12th day until death occurred on the 16th day.


1962 ◽  
Vol 60 (3) ◽  
pp. 311-321 ◽  
Author(s):  
B. Gerichter ◽  
D. L. Boros

An LD 50 doseS. typhi(strain Ty was injected intraperitoneally into white mice, and the number of micro-organisms was determined after 1 min. and subsequently, in the blood, and after 3 hr. and subsequently, in the spleen and liver. The course of the infection was observed for 34 days.The number of bacteria gradually increased in the blood stream during the first post-infective hours. It was possible to differentiate by external signs from the sixth post-infective hour and onwards between sick animals and recovering ones. This difference corresponded to the bacterial concentration in the blood stream and internal organs.In the sick animals the increase in the bacterial count of blood stream continued till 9–10 hr. after the inoculation, when it reached its first peak. During the following 8 hr. a clear decrease in the blood count was evident which was attributed to the ‘clearing mechanism’ of the blood. The onset of a new bacterial rise in the blood stream appeared 18 hr. after the inoculation and reached a second peak during the further 6–8 hr.In contrast to the observed decrease in the bacterial blood count, a steady and gradual increase in the count of the internal organs was seen; it was steadily progressive till the exitus.In the recovering animals a steady decrease in the bacterial blood count was recorded. Between 24 and 26 hr. the number of micro-organisms in the blood and spleen was found to be 400 times less in the recovering animals than in the moribund ones. From 48 hr. and onwards a slow and gradual decrease in the bacterial count of the surviving animals was observed. The blood became sterile after 25 days. In the spleen and liver of the surviving animals after 48 hr. a new increase in the bacterial count is evident, accompanied by hyperplasia of the spleen. The number of bacteria reached a new peak in the liver on the third day and in the spleen on the fourth day after the infection.Subsequently a slow and gradual decrease in the bacterial count was observed in both organs, but even after 34 days a small number of persisting bacteria in the spleen and liver tissue may be found.


1982 ◽  
Vol 60 (12) ◽  
pp. 3409-3419 ◽  
Author(s):  
Annie Jaoul ◽  
Pierre Roubaud

The resistance of common carp (Cyprinus carpio L.) eggs to hot and cold shock has been studied by measuring the survival rate during the course of an incubation at a constant temperature of 20 °C. When incubation was pursued in oxygen-saturated conditions, a 1-h-long thermal shock which occurred during the synchronous segmentation stage had no effect within the temperature range of 8–28 °C. At gastrula stage, this interval reached 0.3 °C and at the end of epiboly it reached 36 °C. With hypoxic incubation conditions, a 1-h postepibolic shock had no effect within the range of 1–36 °C. On the contrary, a 12 °C (or less) preblastulean cold shock or a 30 °C (or more) pregastrulean hot shock induced a significant loss of further resistance to hypoxy. An overoxygenation during the shock did not increase the embryonic resistance. During the synchronous segmentation, the sensitivity to cold shock varied occasionally, possibly in relation with the mitotic cycle. Sensitivity to thermal shock also depended on the gametes' fertility. The resistance to thermic shock was compared with the thermic profiles that are described to be optimum in laboratory conditions at constant temperature, or in natural conditions of development. Hypoxy or hyperoxy cannot be the determining factor in thermic-shock effects on carp eggs: several hypotheses were reviewed to explain the acquisition of an increasing resistance to the variation of the environmental temperature.


2020 ◽  
Vol 10 (14) ◽  
pp. 4983 ◽  
Author(s):  
Intarat Naruemon ◽  
Long Liu ◽  
Dai Liu ◽  
Xiuzhen Ma ◽  
Keiya Nishida

In diesel engines, fuel mixing is an important process in determining the combustion efficiency and emissions level. One of the measures used to achieve fuel mixing is controlling the nature and behavior of the fuel spray by shaping the injection rate. The mechanism underlying the behavior of the spray with varying injection rates before the start of combustion is not fully understood. Therefore, in this research, the fuel injection rate shape is investigated to assess the spraying and mixing behavior. Diesel sprays with different ambient temperatures and injection pressures are modeled using the CONVERGE-CFD software. The validation is performed based on experimental data from an Engine Combustion Network (ECN). The verified models are then used to analyze the characteristics of the diesel spray before and after the end-of-injection (EOI) with four fuel injection rate shapes, including a rectangular injection rate shape (RECT), a quick increase gradual decrease injection rate shape (QIGD), a gradual increase gradual decrease injection rate shape (GIGD), and a gradual increase quick decrease injection rate shape (GIQD). The spray vapor penetrations, liquid lengths, evaporation ratios, Sauter mean diameter (SMDs), distributions of turbulence kinetic energy, temperatures, and equivalence ratios were compared under different injection rate shapes. The results show that the QIGD injection rate shape can enhance mixing during injection, while the GIQD injection rate shape can achieve better mixing after the EOI.


2010 ◽  
Vol 50 (9-11) ◽  
pp. 1783-1788 ◽  
Author(s):  
H. Gualous ◽  
R. Gallay ◽  
G. Alcicek ◽  
B. Tala-Ighil ◽  
A. Oukaour ◽  
...  

Author(s):  
W. J. Abramson ◽  
H. W. Estry ◽  
L. F. Allard

LaB6 emitters are becoming increasingly popular as direct replacements for tungsten filaments in the electron guns of modern electron-beam instruments. These emitters offer order of magnitude increases in beam brightness, and, with appropriate care in operation, a corresponding increase in source lifetime. They are, however, an order of magnitude more expensive, and may be easily damaged (by improper vacuum conditions and thermal shock) during saturation/desaturation operations. These operations typically require several minutes of an operator's attention, which becomes tedious and subject to error, particularly since the emitter must be cooled during sample exchanges to minimize damage from random vacuum excursions. We have designed a control system for LaBg emitters which relieves the operator of the necessity for manually controlling the emitter power, minimizes the danger of accidental improper operation, and makes the use of these emitters routine on multi-user instruments.Figure 1 is a block schematic of the main components of the control system, and Figure 2 shows the control box.


Author(s):  
G.C. Bellolio ◽  
K.S. Lohrmann ◽  
E.M. Dupré

Argopecten purpuratus is a scallop distributed in the Pacific coast of Chile and Peru. Although this species is mass cultured in both countries there is no morphological description available of the development of this bivalve except for few characterizations of some larval stages described for culture purposes. In this work veliger larvae (app. 140 pm length) were examined by the scanning electron microscope (SEM) in order to study some aspects of the organogenesis of this species.Veliger larvae were obtained from hatchery cultures, relaxed with a solution of MgCl2 and killed by slow addition of 21 glutaraldehyde (GA) in seawater (SW). They were fixed in 2% GA in calcium free artificial SW (pH 8.3), rinsed 3 times in calcium free SW, and dehydrated in a graded ethanol series. The larvae were critical point dried and mounted on double scotch tape (DST). To permit internal view, some valves were removed by slightly pressing and lifting the tip of a cactus spine wrapped with DST, The samples were coated with 20 nm gold and examined with a JEOL JSM T-300 operated at 15 KV.


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