The effect of abiotic factors on the toxicity of cypermethrin against the snail Lymnaea acuminata in the control of fascioliasis

2009 ◽  
Vol 83 (1) ◽  
pp. 39-45 ◽  
Author(s):  
V. Singh ◽  
D.K. Singh
Keyword(s):  
Abiotic Factors ◽  
Rank Correlation ◽  
Snail Population ◽  
Similar Treatment ◽  
Alp Activity ◽  
Test Water ◽  
Maximum Inhibition ◽  
Positive Rank ◽  
Sublethal Concentrations ◽  
Lymnaea Acuminata

AbstractEvery month during the year 2006–2007, the 24, 48, 72 and 96 h LC50 values of a molluscicide, cypermethrin, were determined for a snail Lymnaea acuminata, with concomitant estimation of levels of temperature, pH, dissolved oxygen and carbon dioxide and electrical conductivity, both in control and test water. On the basis of a 24 h toxicity assay, it was noted that LC50 values of 10.39, 10.90 and 11.19 mg l− 1 during the months of May, June and July, respectively, were most effective in killing the snails, while the molluscicide was least effective in the month of January, when its 24 h LC50 was 65.84 mg l− 1.There was a significant positive correlation between LC50 of cypermethrin and levels of dissolved O2/pH of water in corresponding months. On the contrary, a negative correlation was observed between LC50 and dissolved CO2/temperature of test water in the same months. In order to ascertain that such a relationship between toxicity and abiotic factors is not coincidental, the nervous tissue of the snail was assayed for the activity of acetylcholinesterase (AChE), acid phosphatase (ACP) and alkaline phosphatase (ALP) to sublethal concentrations (40% and 80%) of 24 h LC50 during each of the 12 months of the same year. The findings confirmed that abiotic factors indeed influence toxicity of cypermethrin in the snail. A significant positive rank correlation between AChE, ACP and ALP activity did exist following exposure to the corresponding sublethal concentrations. Moreover, there was a maximum inhibition of 61.29 and 76.16% of AChE and ACP, respectively, in snails exposed to 80% of the 24 h LC50 in the month of May. A similar treatment caused a maximum inhibition of 70.53% of ALP activity in the month of June. This work shows conclusively that the best time to control the snail population with cypermethrin is during the months of May and June.

scholarly journals Effect of exposure to sublethal concentrations of zinc cyanide on tissue ATPase activity in the fresh water fish, Cirrhinus mrigala (Ham)

2012 ◽  
Vol 64 (1) ◽  
pp. 257-263 ◽  
Author(s):  
Shwetha Dube ◽  
B.B. Hosetti
Keyword(s):  
Adaptive Response ◽  
Aquatic Organisms ◽  
Fresh Water Fish ◽  
Cirrhinus Mrigala ◽  
Biomarkers Of Exposure ◽  
Maximum Inhibition ◽  
Water Fish ◽  
Treated Fish ◽  
Cyanide Intoxication ◽  
Sublethal Concentrations

The present study was conducted to evaluate the effects of zinc cyanide (Zn(CN)2) on the ATPase (Na+-K+-, Mg2+, Ca2+) activity of the freshwater fish Cirrhinus mrigala (Ham). Fish were exposed to two sublethal concentrations (0.114 and 0.068 mg/L) and the effects were studied in the liver, muscle and gill tissues at the end of 5, 10 and 15 days of exposure. Cyanide intoxication resulted in marked changes in ATPases, represented by a significant decrease in the activities. Maximum inhibition was observed at higher concentration. The order of inhibition in the activity was Na+-K+-> Ca2+ > Mg2+ ATPase. These results imply an immediate adaptive response to the stress, demonstrating alterations in ATPase activities in the tissues of cyanide-treated fish. The present study clearly proposes that ATPases can be used as biomarkers of exposure of aquatic organisms to cyanide intoxication.

5β-PREGNAN-3α-OL-20-ONE IN URINE

1962 ◽  
Vol 41 (2) ◽  
pp. 247-258 ◽  
Author(s):  
H. J. van der Molen ◽  
U. W. Kleef
Keyword(s):  
Acid Hydrolysis ◽  
Rank Correlation ◽  
List Type ◽  
Adrenal Hyperplasia ◽  
Pregnant Females ◽  
Partial Formation ◽  
Males And Females ◽  
Normal Males ◽  
Positive Rank ◽  
Normal Adults

ABSTRACT The occurrence, metabolic formation and degradation of 5β-pregnan-3α-ol-20-one are reviewed. Estimation of 5β-pregnan-3α-ol-20-one in urine has shown that: under acid conditions 5β-pregnane-3α,17α,20α-triol is destroyed with partial formation of pregnanolone; however, the amounts of pregnanolone that are formed, do not interfere with the estimation of pregnanolone in urine of normal adults after acid hydrolysis and offer no explanation for the high levels of pregnanolone in urine of patients with adrenal hyperplasia, as observed by some investigators. Excretion of pregnanolone found in urine during pregnancy (1–15 mg/day) is considerably below the levels reported in the literature so far. Normal adults excrete pregnanolone in urine in amounts within a range of 0.05–0.70 mg/day. There is a positive rank-correlation between the excretion of pregnanolone and pregnanediol in urine of normal males and females and of pregnant females. After administration of ACTH to adults an increase in the excretion of pregnanolone in urine could not always be demonstrated.

Planned and Post Hoc Comparisons in Tests of Concordance and Discordance forG Groups of Judges

1983 ◽  
Vol 8 (3) ◽  
pp. 187-205 ◽  
Author(s):  
Ronald C. Serlin ◽  
Leonard A. Marascuilo
Keyword(s):  
Rank Correlation ◽  
Model Tests ◽  
Friedman's Test ◽  
Group Situation ◽  
Coefficient Of Concordance ◽  
The Mean ◽  
Using Data ◽  
Post Hoc ◽  
Positive Rank ◽  
Level Of Agreement

Statistical procedures for making comparisons on the ranking of a set ofK elements, wines, people, and so forth, have been worked out for the case in which the ranking is done by a single group ofn people. In this special situation, Friedman’s test can be called upon to assess the significance of differences in mean ranking, and Kendall’s coefficient of concordance can be used to measure the level of agreement among the individuals doing the ranking. Unfortunately, the problem of comparingG groups of subjects to determine whether or not they produce the same mean ranking has, until recently, remained unanswered. A procedure was developed for testing two-group concordance by Schucany and Frawley. Hollander and Sethuraman have questioned this procedure and have provided an alternative model for investigating the same problem. It is easy to show that the Schucany and Frawley model tests for positive rank correlation in the mean ranks as an alternative, whereas the Hollander and Sethuraman model tests identity of mean ranks across theK compared elements as the null. In this article, these two models are examined, the criticism is evaluated, and both models are extended to theG group situation. The extension to planned and post hoc comparisons is illustrated using data based on a study described by Marascuilo and Dagenais.

scholarly journals Effect of environmental factors on the fecundity, hatchability and survival of snail Lymnaea (Radix) acuminata (Lamarck): vector of fascioliasis

2009 ◽  
Vol 8 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Harsh Vardhan Jigyasu ◽  
Vinay Kumar Singh
Keyword(s):  
Significant Variation ◽  
Development Process ◽  
Dark Period ◽  
Abiotic Factors ◽  
Significant Negative Correlation ◽  
Polluted Water ◽  
Control Group ◽  
Reproductive Ability ◽  
Group 2 ◽  
Lymnaea Acuminata

Lymnaea acuminata breeds round the year. The effect of pH, temperature, dissolved oxygen, carbon dioxide, light/dark period and clean/polluted water on the fecundity, hatchability and survival of young snails of L. acuminata were studied. It was observed that these environmental variant abiotic factors caused a significant variation in fecundity, hatchability and survival of young snails. Maximum reproduction of this snail was observed in the months of March to May. A significant positive correlation (p<0.05) between D.O. (3.1–7.7 ppm)/pH (7.01–8.96) of water with fecundity (6.0–196.33/20 snails), hatchability (54.69–96.91%) and survival (61.3–95.86%) of young snails was observed for each month and each interval of 24–72 h. In contrast, a significant negative correlation between dissolved CO2 (4.6–16.6 ppm)/temperature (16–37°C) of water was noted with fecundity, hatchability and survival of snails. Percent hatchability in the eggs in different regimens of water was between 96.91–54.69%. The hatching period was prolonged (2–14 days) in snail exposed to different groups of water compared to the control group (2–9 d). This study conclusively shows that variant abiotic factors in different months of the year can significantly alter the reproductive ability and development process in the snail Lymnaea acuminata.

Changes in respiratory movements of the human vocal cords during hyperpnea

1982 ◽  
Vol 52 (3) ◽  
pp. 780-785 ◽  
Author(s):  
S. J. England ◽  
D. Bartlett
Keyword(s):  
Vocal Cord ◽  
Rank Correlation ◽  
Respiratory Cycle ◽  
Vocal Cords ◽  
Expiratory Phase ◽  
Expiratory Time ◽  
Young Subjects ◽  
Exercise Induced ◽  
Positive Rank ◽  
Respiratory Movements

Five healthy young subjects were studied to assess the changes in vocal cord movements that occur between resting breathing and hyperpnea. Both hypercapnia and exercise induced decreases in the extent of narrowing of the glottic aperture occurring during expiration. In addition, four of the subjects showed a significant positive rank correlation between the extent of narrowing of the glottis and the observed length of the expiratory phase of the respiratory cycle. These results indicate that the braking of expiratory airflow by movements of the vocal cords toward the midline is reduced during hyperpnea at the same time that expiratory time is decreased.

scholarly journals Fascioliasis Control:In VivoandIn VitroPhytotherapy of Vector Snail to KillFasciolaLarva

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Kumari Sunita ◽  
D. K. Singh
Keyword(s):  
Life Cycle ◽  
Ferulic Acid ◽  
Aquatic Ecosystem ◽  
Active Component ◽  
Infected Snail ◽  
Threshold Level ◽  
Snail Population ◽  
Lymnaea Acuminata

Snail is one of the important components of an aquatic ecosystem, it acts as intermediate host ofFasciolaspecies. Control of snail population below a certain threshold level is one of the important methods in the campaign to reduce the incidence of fascioliasis. Life cycle of the parasite can be interrupted by killing the snail orFasciolalarva redia and cercaria in the snail body.In vivoandin vitrotoxicity of the plant products and their active component such as citral, ferulic acid, umbelliferone, azadirachtin, and allicin against larva ofFasciolain infected snailLymnaea acuminatawere tested. Mortality of larvae were observed at 2 h, 4 h, 6 h, and 8 h, of treatment. Inin vivotreatment, azadirachtin caused highest mortality in redia and cercaria larva (8 h, LC500.11, and 0.05 mg/L) whereas inin vitrocondition allicin was highly toxic against redia and cercaria (8 h, LC500.01, and 0.009 mg/L). Toxicity of citral was lowest against redia and cercaria larva.

scholarly journals Feeding of Bait to Snail Lymnaea acuminata and Their Effect on Certain Enzyme in the Nervous Tissue

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Pradeep Kumar ◽  
V. K. Singh ◽  
D. K. Singh
Keyword(s):  
Alkaline Phosphatase ◽  
Nervous Tissue ◽  
Ache Activity ◽  
Significant Inhibition ◽  
Control Activity ◽  
Maximum Inhibition ◽  
Clear Glass ◽  
Long Time ◽  
Amino Acid Methionine ◽  
Lymnaea Acuminata

Fascioliasis, a snail-borne parasitic zoonosis, has been recognized for a long time because of its major veterinary and human impact. Different Bait formulations were fed to the snail Lymnaea acuminata in clear glass aquaria having diameter of 30 cm. Snail attractant containing bait formulations was prepared from different binary combination (1 : 1 ratio) of carbohydrates (glucose, starch 10 mM) and amino acid (methionine, histidine 10 mM) in 100 ml of 2% agar solution + sublethal (20% and 60% of 24 h and 96 h LC50) doses of different molluscicides (eugenol, ferulic acid, umbelliferone, and limonene). Snails fed on bait containing sub-lethal concentration of different molluscicides and the snail attractant, causing a significant inhibition in alkaline phosphatase (ALP) and acetylcholinesterase (AChE) activity in the nervous tissue of the vector snail L. acuminata. Maximum inhibition in ALP (20% of control) and AChE (49.49% of control) activity was observed in the nervous tissue of the L. acuminata exposed to 60% of 96 h LC50 of eugenol in the bait pellets containing starch + histidine, starch + methionine, respectively.

Factors influencing average milk yield of herds at two levels of production

1960 ◽  
Vol 2 (2) ◽  
pp. 117-130 ◽  
Author(s):  
Gerald Wiener
Keyword(s):  
Body Size ◽  
Milk Yield ◽  
Management Practices ◽  
Rank Correlation ◽  
Feeding Practice ◽  
High Group ◽  
Factors Influencing ◽  
Yield Difference ◽  
The Difference ◽  
Positive Rank

An experiment was started in 1950 designed to find out what proportion of the difference in milk yield between herds is genetic in origin. Sixty-five pairs of twins were split at birth equally between farms having high-yielding herds and farms having low-yielding herds. A previous paper on this experiment reported on the growth of the twins, the present paper on milk yield and on management practices in the herds.Twenty-four pairs of twins survived to complete one lactation and these provide an estimate of 24%±18% for the genetic part of the difference between the herds.Aspects of rearing of the twins and of management of the herds were examined. Twins in the high-yielding herds were served and calved earlier than those in the low-yielding group but they had a longer interval between service and calving. Differences between average heifer yields and average cow yields were from one-and-a-half to two times greater in the high- than in the low-yielding herd group. There were no obvious quantitative differences in feeding practice between the two groups although differences in body size suggest that twins in the high group were done better. For the age at first service there was a positive rank correlation of 0·30 between body size differences and subsequent differences in first lactation milk yield. There was no single factor of management or environment which appeared to be the cause of the yield difference between the herds.

scholarly journals Environmental stress and parasitism as drivers of population dynamics of Mesodesma donacium at its northern biogeographic range

2011 ◽  
Vol 68 (5) ◽  
pp. 823-833 ◽  
Author(s):  
José M. Riascos ◽  
Olaf Heilmayer ◽  
Marcelo E. Oliva ◽  
Jürgen Laudien
Keyword(s):  
Population Dynamics ◽  
Environmental Stress ◽  
Body Mass ◽  
High Mortality ◽  
Abiotic Factors ◽  
Rank Correlation ◽  
Parasite Load ◽  
Parasite Prevalence ◽  
Strong Impact ◽  
Somatic Production

Abstract Riascos, J. M., Heilmayer, O., Oliva, M. E., and Laudien, J. 2011. Environmental stress and parasitism as drivers of population dynamics of Mesodesma donacium at its northern biogeographic range. – ICES Journal of Marine Science, 68: 823–833. Mesodesma donacium is a commercially important bivalve in Chile and Peru. During strong El Niño events, populations at the northern end of its geographic distribution are wiped out, so to understand its threshold responses to biotic and abiotic factors, the population dynamics of one of the northernmost population remnants was analysed between 2005 and 2007. Strong interannual differences were found in abundance, body mass, growth rate, somatic production, and the prevalence of the parasite Polydora bioccipitalis. A Spearman rank correlation analysis showed that changes in beach slope, seemingly linked to repeated storm surges, negatively affected the clam's abundance and seemingly also affected growth, mortality, body mass somatic production, and parasite prevalence. Infestation by P. bioccipitalis was restricted to adult clams. Juvenile clams suffered high mortality because they inhabit the intertidal zone, where wave action is strong. Larger clams also showed high mortality, which seemed best explained by a synergistic effect of parasite load and environmental stress. This parasite-climate-driven mortality of larger clams had a strong impact on somatic production and implied a dramatic loss of fecundity (82%), which may significantly affect the ability of the species to recover its former abundance and distribution.

Sign in / Sign up

Export Citation Format

Share Document