Results 251 to 260 of about 112,587 (303)

ROBUST ESTIMATION OF THE MEDIAN LETHAL DOSE

Journal of Biopharmaceutical Statistics, 2002
Alternatives to M-estimation for robust estimation of the median lethal dose in biological assays are developed. A class of link functions based on the Student-t distribution is proposed, where degrees of freedom are estimated from the data by maximum likelihood. Other alternatives include slash and finite mixture distributions.
G E, Kelly, J K, Lindsey
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Interval Estimation of the Median Lethal Dose

Biometrics, 1986
Assuming a logistic dose-response curve, one can construct a confidence interval for the LD50 from the asymptotic likelihood ratio test. Reasons are given for preferring this likelihood ratio interval to the established interval calculated by applying Fieller's theorem to the maximum likelihood estimates.
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The median lethal dose and its estimation

Archives of Toxicology, 1985
An important paper by Zbinden and Fluri-Roversi (1981) has shown the many weaknesses in any policy or regulatory system that regards an estimated LD50 in an animal species as an adequate guide to toxicity in man. The present paper draws attention to some statistical aspects of LD50 estimation that are too often neglected or misunderstood when this ...
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Estimation of Median Lethal Dose of Cypermethrin and Betacyfluthrin

INTERNATIONAL JOURNAL OF TOXICOLOGICAL AND PHARMACOLOGICAL RESEARCH, 2017
Present study was aimed to evaluate the median lethal dose (LD50) of two broadly used, type II pyrethroid pesticides Cypermethrin and Beta-cyfluthrin against Wistar albino rats. The albino rats corresponding to experimental sets were orally administrated different doses of selected pyrethroids for estimation of median lethal dose.
Brijender Bhushan, Prabhu Narain Saxena
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Approximate lethal dose versus median lethal dose in acute toxicity testing of pharmaceuticals

Archives of Toxicology, 1989
The relation between approximate lethal doses (ALD, i.e. the lowest dose at which mortality occurs) and the corresponding median lethal doses (LD50) was investigated in 231 acute toxicity studies in mice and rats. The ALD values were divided into four classes (less than 5 mg/kg, 5-50 mg/kg, 50-500 mg/kg, 500-2000 mg/kg) and the LD50/ALD factors were ...
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Median Lethal Dose for Guinea Pigs of Cobalt-60 Gamma Irradiation

Radiation Research, 1960
The acute 30-day median lethal dose in Hartley guinea pigs was determined for cobalt-60 gamma -irradiation. The median lethal dose was found to be 326 rads, Change in weight of the irradiated animals was recorded for a period of 30 days. Extravasation of blood into viscera and serous cavities was the most frequent finding at autopsy. (auth)
W T, NEWTON, M, TER-POGOSSIAN
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The Median Lethal Dose-Design and Estimation

Journal of the Royal Statistical Society: Series D (The Statistician), 2001
Summary. A biological assay from a pharmaceutical company is simulated with various designs and a range of parameter values. Three estimation techniques-Fieller's method, profile likelihood and the bootstrap-of finding confidence intervals for the median lethal dose LD50 are compared.
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Corrigendum: The Median Lethal Dose-Design and Estimation

Journal of the Royal Statistical Society: Series D (The Statistician), 2001
I am grateful to Graham Healey, Huntingdon Life Sciences Limited, and Jochen Mueller-Cohrs, Aventis Behring GmbH, Marburg, for pointing out the following error. Owing to a computing error in calculating the deviance the results on the likelihood ratio (LR) method in Table 1 were incorrect. It has now been recomputed and is shown below. Section 4 should
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