Acceleration of the growth of populations and of the multiplication of tetrathyridia of Mesocestoides corti Hoeppli, 1925 (Cestoda: Cyclophyllidea) by some cytostatic agents

1973 ◽  
Vol 51 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Marie Novak ◽  
George Lubinsky
Keyword(s):  
Echinococcus Multilocularis ◽  
Considerable Increase ◽  
Single Injection ◽  
Total Biomass ◽  
Cytostatic Agents ◽  
Average Size

Experiments with tetrathyridia of Mesocestoides corti implanted intraperitoneally into LDF1, SEC, and SWR mice showed that a single injection of cyclophosphamide, 200 mg/kg 1 day after infection, increased the total biomass of tetrathyridial populations in mice dissected 50 days later by 50 to 200%. Similar, though less pronounced, increases in the total biomass of populations were produced by dactinomycin, 0.35 mg/kg once a week, for 4 to 6 weeks. The average size of individual tetrathyridia decreased despite a considerable increase in the total biomass of their populations.The parasiticides lucanthone, which inhibits the growth of Echinococcus multilocularis cysts, and quinacrine, which is inactive in this respect, accelerate the growth of the biomass of tetrathyridial populations much less than the cytostatic agents cyclophosphamide and dactinomycin.

scholarly journals Effects of Indomethacin and Ibuprofen on Cerebral Metabolism and Blood Flow in Traumatized Brain

1983 ◽  
Vol 3 (4) ◽  
pp. 448-459 ◽  
Author(s):  
Hanna M. Pappius ◽  
Leonhard S. Wolfe
Keyword(s):  
Blood Flow ◽  
Considerable Increase ◽  
Glucose Utilization ◽  
Single Injection ◽  
Cerebral Metabolism ◽  
Local Cerebral Blood Flow ◽  
Lesion Area ◽  
Local Cerebral Glucose Utilization ◽  
Biphasic Effect ◽  
Prostaglandin System

Local cerebral glucose utilization (LCGU) and local cerebral blood flow (LCBF) were studied by autoradiographic techniques in indomethacin- and ibuprofen-treated rats with focal cortical freezing lesions. Widespread depression of LCGU, which developed with time after the lesion in untreated animals was significantly diminished by the prostaglandin synthetase inhibitors indomethacin (single injection 7.5 mg/kg) and ibuprofen (36 mg/kg/day). Both drugs were effective when given 6 h before or up to 24 h after the lesion was made. The effect of the drugs was most striking in cortical areas of the traumatized hemisphere, where the depression was most profound in untreated animals. Thus, 3 days afer the lesion, average LCGU in these regions was 46%, 86%, and 98% of normal in untreated, indomethacin-pretreated, and ibuprofen-pretreated rats, respectively. Prostaglandin formation was completely inhibited in the lesion area in the indomethacin-treated rats (PGF2α 1.8 ng/g, compared to 57.5 ng/g in untreated and 1.4 ng/g in nonlesioned animals). The results suggest that some components of the prostaglandin system are involved in mechanisms underlying a widespread depression in functional state of the rat brain that develops in response to injury. In control animals, indomethacin was shown to have a biphasic effect on LCBF, an early depression shown previously by others followed at 24 h by a considerable increase.

Transmission dynamics of Echinococcus multilocularis; its reproduction number, persistence in an area of low rodent prevalence, and effectiveness of control

Parasitology ◽  
2005 ◽  
Vol 131 (1) ◽  
pp. 133-140 ◽  
Author(s):  
K. TAKUMI ◽  
J. VAN DER GIESSEN
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Central Europe ◽  
Definitive Host ◽  
Echinococcus Multilocularis ◽  
Reproduction Number ◽  
Parasite Burden ◽  
Host Population ◽  
Total Biomass ◽  
Control Campaign

On the basis of high prevalences of Echinococcus multilocularis in the growing fox populations in Central Europe, its total biomass may have increased significantly in the past 20 years. E. multilocularis is now also found in areas outside the known endemic area in Central Europe. Therefore, E. multilocularis, the causative agent of a serious parasitic zoonosis, might be of major concern for public health and a challenge to control. Some experimental field trials to control E. multilocularis using an anti-worm drug reduced parasite burden in a contaminated region during the control campaign, but failed to eradicate the parasite completely. It was our aim to develop a mathematical model describing the biomass of egg, larval, and adult worm stages of the E. multilocularis life-cycle, and simulate a hypothetical control campaign. Additionally, we derived the reproduction number of this parasite and explored conditions for the persistence of the parasite's life-cycle. Our model shows that while control campaigns rapidly reduce the worm burden in the definitive host, and consequently eggs in the environment, the pool of larvae in the intermediate host remains large. The parasite's life-cycle persists in a region where prevalence in the intermediate host is low (∼1%). Therefore, we conclude that the parasite is likely to re-emerge if control is discontinued on the basis of reduced worm population. Continued treatment of the definitive host is required to eradicate the larval stage of the parasite from the intermediate host population.

scholarly journals Effects of Probiotics on Growth and Production of Monosex Tilapia (Oreochromis Niloticus) in Nylon Net Cages at Dekar Haor, Sunamganj, Bangladesh

2018 ◽  
Vol 44 (1) ◽  
pp. 69-78
Author(s):  
P Das ◽  
MS Islam ◽  
M Biswas ◽  
PR Das ◽  
ASM Arif
Keyword(s):  
Survival Rate ◽  
Oreochromis Niloticus ◽  
Conversion Ratio ◽  
Production Performance ◽  
Total Biomass ◽  
Fish Production ◽  
Food Conversion ◽  
Net Profit ◽  
Average Size ◽  
Net Cages

To assess the effect of probiotics on growth, survival rate and production performance of all monosex tilapia (Oreochromis niloticus) for a period of 120 days in 2016 in nylon net cages placed in Dekar haor of Sunamganj district. The study was categorized into four treatments as T1 (brand a), T2 (brand b), T3 (brand c) and T4 (control) based on probiotics and each having three replicates. Cages were stocked with nursed male tilapia fry at a density of 35 nos./m3 with average size of 14.33 ± 6.41 - 16.33 ± 3.15 g. Tilapia of all the cages were fed with commercial mega floating feed at a decreasing rate of 10 - 5% of total biomass thrice daily. Feed was supplemented with probiotics at a rate of 0.5 g/kg. Comparatively higher growth (307.33 ± 33.92 g), survival rate (97.6 ± 4.90%), yield (10.5 ± 1.15 kg/m3), net profit (Tk.798.96 ± 90.85/m3) and lower food conversion ratio (1.16) were secured in T3 than that of other treatments, which were manifolds higher than the earthen freshwater and brackish waterbodies. Therefore, results of the study reveal that probiotics may be used in aquaculture for increasing fish production. Asiat. Soc. Bangladesh, Sci. 44(1): 69-78, June 2018

Attempts at chemotherapy of Echinococcus multilocularis infections in rodents

1969 ◽  
Vol 47 (5) ◽  
pp. 1001-1004 ◽  
Author(s):  
G. Lubinsky
Keyword(s):  
Echinococcus Multilocularis ◽  
Single Injection

Attempts were made to inhibit the growth of vegetatively propagated Echinococcus multilocularis cysts in mice by using two antischistosomals, two antimalarials, two organophosphorous parasiticides, and one cytostatic, cyclophosphamide. Of these only the latter and lucanthone inhibited the growth of cysts; 7 to 14 injections of 100 mg/kg of lucanthone inhibited it by 30 to 60%. A single injection of cyclophosphamide, 200 mg/kg, 1 week after infection, inhibited the growth by 75 to 90%. This retardation was still apparent 3 months after the injection of cyclophosphamide.

Attempts at chemotherapy of Echinococcus multilocularis infections in rodents. II. A study of some parasiticides and cytostatic agents

1971 ◽  
Vol 49 (10) ◽  
pp. 1301-1304 ◽  
Author(s):  
G. Lubinsky ◽  
Ch.-F. Lee ◽  
R. W. Baron
Keyword(s):  
Echinococcus Multilocularis ◽  
Cytostatic Agents

Seven parasiticides were studied for their ability to inhibit the growth of Echinococcus cysts, but none was found to be active. Of the six cytostatic agents examined, demecolcine and dactinomycin inhibited the growth of cysts, but only when used in toxic doses.

Crustacean Zooplankton Communities of Acidic, Metal-Contaminated Lakes Near Sudbury, Ontario

1980 ◽  
Vol 37 (12) ◽  
pp. 2282-2293 ◽  
Author(s):  
N. D. Yan ◽  
R. Strus
Keyword(s):  
Phytoplankton Biomass ◽  
Quantitative Data ◽  
Zooplankton Biomass ◽  
Crustacean Zooplankton ◽  
Total Biomass ◽  
Metal Levels ◽  
Total Phytoplankton ◽  
Average Biomass ◽  
Average Size ◽  
Zooplankton Communities

Crustacean zooplankton data for 1973 to 1978 from Clearwater Lake, an acidic, metal-contaminated lake near Sudbury, Ontario, are presented and compared with data from four other contaminated lakes near Sudbury and six uncontaminated lakes in the Muskoka–Haliburton Region of Ontario. Species richness and community biomass were reduced in the contaminated lakes, the latter because of reductions in numbers and average size of community dominants. The greatest reductions were observed in the lake with the highest metal levels, Hannah Lake. Cladocera were much more important contributors to total biomass in the contaminated lakes, forming, for example, 80–96% of the average biomass for the ice-free period in Clearwater Lake. An average of 89% of all adult Crustacea observed in Clearwater Lake were Bosmina longirostris (O. F. Müller). Zooplankton biomass in the contaminated lakes, excluding Hannah Lake, was not significantly correlated with pH, with Cu, Ni, or TP concentrations, or with total phytoplankton biomass. While similarities existed, community structure was different from that of acidic lakes in the La Cloche Mountains that were not contaminated with Cu or Ni. Hypotheses relating to how acidification alters typical phytoplankton–zooplankton interactions were constructed. The scarcity of quantitative data required to test such hypotheses is emphasized.

scholarly journals The invariances of power law size distributions

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2074 ◽  
Author(s):  
Steven A. Frank
Keyword(s):  
Power Law ◽  
Tree Size ◽  
Total Biomass ◽  
Common Pattern ◽  
Simple Interpretation ◽  
Shape Pattern ◽  
Component Processes ◽  
Average Size ◽  
Small Things ◽  
Invariant Properties

Size varies. Small things are typically more frequent than large things. The logarithm of frequency often declines linearly with the logarithm of size. That power law relation forms one of the common patterns of nature. Why does the complexity of nature reduce to such a simple pattern? Why do things as different as tree size and enzyme rate follow similarly simple patterns? Here I analyze such patterns by their invariant properties. For example, a common pattern should not change when adding a constant value to all observations. That shift is essentially the renumbering of the points on a ruler without changing the metric information provided by the ruler. A ruler is shift invariant only when its scale is properly calibrated to the pattern being measured. Stretch invariance corresponds to the conservation of the total amount of something, such as the total biomass and consequently the average size. Rotational invariance corresponds to pattern that does not depend on the order in which underlying processes occur, for example, a scale that additively combines the component processes leading to observed values. I use tree size as an example to illustrate how the key invariances shape pattern. A simple interpretation of common pattern follows. That simple interpretation connects the normal distribution to a wide variety of other common patterns through the transformations of scale set by the fundamental invariances.

Rehabilitation of degraded grasslands in north Syria: use of farmer participatory research to encourage the sowing of annual pasture legumes

1999 ◽  
Vol 35 (4) ◽  
pp. 489-506 ◽  
Author(s):  
F. GHASSALI ◽  
P. S. COCKS ◽  
A. E. OSMAN ◽  
G. GINTZBURGER ◽  
S. CHRISTIANSEN ◽  
...  
Keyword(s):  
Common Property ◽  
Farming Systems ◽  
Total Biomass ◽  
Pasture Legumes ◽  
Farmer Participatory Research ◽  
Legume Seeds ◽  
Increase Productivity ◽  
Series Of Experiments ◽  
Average Size ◽  
Ownership Of Land

A series of experiments on communally-owned grasslands in the barley–livestock zone of north Syria were conducted to test the hypothesis that introduction of Mediterranean annual legumes will increase productivity. The experiments were preceded by a survey to determine farmers' attitudes, describe the farming systems and to select appropriate collaborators. The first experiment examined the establishment of medics (Medicago spp.) and clovers (Trifolium spp.) distributed by hand, and monitored their effects on biomass and seedbank size. Later experiments extended these results to other villages. The principles of farmer participation in research were used to overcome the constraints imposed by the communal ownership of land. The survey revealed that the average size of the 20 villages was 36 families and that each village owned 887 sheep and 790 ha land. All villages had access to communally-owned grasslands, although their dependence on income from sheep varied greatly. These villages were subsequently divided into groups of high, intermediate and low potential.Of the 11 clovers sown in the first experiment, seed numbers of T. tomentosum, T. purpureum, T. haussknechtii, T. pilulare and T. resupinatum increased over three years. By 1996, there were more than 3000 legume seeds m−2 in the seeded treatment compared with less than 2000 in the unseeded treatment (mainly the naturally-occurring Trigonella monspeliaca). The number of medic and clover seedlings also increased significantly, while the number of Trigonella seedlings decreased significantly. Biomass production increased in the final two years and there was no response to added phosphorus.There were similar results in the later experiments. Seedbank size was greater in seeded treatments than in unseeded treatments, there were more seedlings in the seeded treatments, and the most successful species were T. campestre, T. tomentosum, T. speciosum and M. rigidula. The response in biomass was limited to the legume component, although total biomass increased in at least one of the two years. The highest biomass produced was 1112 kg ha−1 and there was no response to added phosphorus.The results suggested that the on-station research previously conducted at ICARDA headquarters was applicable to communally-owned land, although important modifications were needed. For example, at ICARDA phosphorus was necessary to stimulate the growth of legumes; in contrast, it was necessary to sow legumes at the four villages involved in these experiments. The results also suggested that the grasslands were common property, owned and controlled by defined groups of farmers.

scholarly journals Dynamics of closed areas in Norway lobster fisheries

2008 ◽  
Vol 65 (9) ◽  
pp. 1600-1609 ◽  
Author(s):  
I. Philip Smith ◽  
Antony C. Jensen
Keyword(s):  
Fishing Effort ◽  
Fishing Ground ◽  
Total Biomass ◽  
Structured Population Model ◽  
Closed Area ◽  
Structured Population ◽  
Norway Lobster ◽  
Stock Biomass ◽  
Age Structured ◽  
Average Size

AbstractSmith, I. P., and Jensen, A. C. 2008. Dynamics of closed areas in Norway lobster fisheries. – ICES Journal of Marine Science, 65: 1600–1609. A dynamic, age-structured population model was developed to investigate the potential effects of introducing a closed area to a fishery for a species with limited adult mobility and planktonic dispersal of larvae, using biological and fishery information from a Norway lobster fishery in eastern Scotland. Simulated closure of part of the fishing grounds led to a long-term increase in total biomass and recruitment to the fished zone, but the larval subsidy did not compensate for the loss of fishing ground, and fishery yield was reduced under all modelled combinations of closed-area size and prior fishing effort. Concentration of effort in the fished zone and increased recruitment there led to reduced average size, and therefore value, of animals in the catch, as well as increased destruction of biomass by discarding undersized lobsters. Implementation of a closed area also led to oscillations in stock biomass, recruitment, and yield over several years after the closure, particularly with large closed areas and high fishing effort.

scholarly journals The invariances of power law size distributions

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2074 ◽  
Author(s):  
Steven A. Frank
Keyword(s):  
Power Law ◽  
Tree Size ◽  
Total Biomass ◽  
Common Pattern ◽  
Simple Interpretation ◽  
Shape Pattern ◽  
Component Processes ◽  
Average Size ◽  
Small Things ◽  
Invariant Properties

Size varies. Small things are typically more frequent than large things. The logarithm of frequency often declines linearly with the logarithm of size. That power law relation forms one of the common patterns of nature. Why does the complexity of nature reduce to such a simple pattern? Why do things as different as tree size and enzyme rate follow similarly simple patterns? Here I analyze such patterns by their invariant properties. For example, a common pattern should not change when adding a constant value to all observations. That shift is essentially the renumbering of the points on a ruler without changing the metric information provided by the ruler. A ruler is shift invariant only when its scale is properly calibrated to the pattern being measured. Stretch invariance corresponds to the conservation of the total amount of something, such as the total biomass and consequently the average size. Rotational invariance corresponds to pattern that does not depend on the order in which underlying processes occur, for example, a scale that additively combines the component processes leading to observed values. I use tree size as an example to illustrate how the key invariances shape pattern. A simple interpretation of common pattern follows. That simple interpretation connects the normal distribution to a wide variety of other common patterns through the transformations of scale set by the fundamental invariances.

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