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Topic acute toxicity of Fitomas-E in honey bees (Apis mellifera)  [PDF]
Yana González,Ramón Montano,Axel Mancebo,Consuelo González
RETEL : Revista de Toxicología en Línea , 2010,
Abstract: FitoMas–E is a formulation obtained by ICIDCA. Its main uses are nutrition improvement, flowering and fructification, maturation of the cane, herbicide action enhancer, soil ameliorative, and germination maximizer. The objective of this work was to evaluate the potential contact toxicity of Fitomas-E to honey bees. The product was applied in a single topic dose of 100 μg per bee. Forty four honey bees of the Apis mellifera species were randomly distributed in two experimental groups, a control and a treated group (Fitomas-E). Mortality of the bee and the appearance of toxicity signs at 4, 24 and 48 hours after the test were the variables analyzed. The study culminated with 13.13 % of survival in the Control Group and 27.27% in the Treated Group. Concerning clinical observations, the animals did not show toxic signs, no alterations in their behavior attributed to the administration of the test substance. According to the results obtained in this highly sensitive species for ecotoxicological tests, it’s possible to conclude that Fitomas-E DL50 is higher than 100 μg per bee.
Implementation of Fuzzy Rule Based Technical Indicator in Share Market
M. Shahjalal,Abeda Sultana,Nirmal Kanti Mitra,A.F.M. Khodadad Khan
The International Journal of Applied Economics and Finance , 2012,
Abstract: Technical indicators are used in the stock and the currency markets for buying and selling decisions. The aim of this study was to develop a fuzzy rule based technical indicator for stock markets. Generalized volumes and generalized prices are used as linguistic variables. The Z-shaped, S-shaped and Triangular fuzzy numbers are used in this study. Success rates have been tested by real time trading and backward testing method. This fuzzy rule based indicator indicates a buy, hold or sell signal. The signals are agreed well with the classical technical indicators.
Peteira,Belkis; Fernández,Arais; Rodríguez,H; González,E;
Revista de Protecci?3n Vegetal , 2008,
Abstract: the use of resistance inducers in plants appears as an ecologically amicable and attractive alternative for producers. in this work, the effect of fitomas on the induction of different enzymatic systems associated with the defense mechanisms in rice plants inoculated with steneotarsonemus spinki was studied and compared with that caused by bion under identical conditions. fitomas was shown to be as effective in decreasing the mite population as when bion was applied. it caused the activation of enzymes such as peroxidases, polyphenol oxidases, phenylalanine ammonia liases and chitinases.
In vitro bioassay as a predictor of in vivo response
Ross Barnard, Konstantin G Gurevich
Theoretical Biology and Medical Modelling , 2005, DOI: 10.1186/1742-4682-2-3
Abstract: For dose-response curve reaches a plateau in vitro we demonstrated that the in vivo response has only one maximum. For biphasic patterns of biological response in vitro both the bimodal and biphasic in vivo responses might be observed.As the main result of this work we have demonstrated that in vivo responses might be predicted from dose-effect curves measured in vitro.In vitro bioassay is very useful in biomedical experiments. It has the potential to yield very important data about molecular mechanism of action of any biologically active compounds. However, the major challenge for such experiments is extrapolation to in vivo responses. Unfortunately, there is a substantial discrepancy between in vitro and in vivo experiments, and there is a paucity of work directed to prediction of in vivo response from in vitro bioassay. So, the purpose of the present work was development of a theoretical framework to enable improved prediction of in vivo response from in vitro bioassay results.A survey of literature revealed that most cases of dose-effect curves for in vitro experiments fall into three classes. They are:? monophasic response;? biphasic pattern;? bimodal or polymodal dose-effect curve.MONOPHASIC RESPONSE is the form most commonly reported in articles on in vitro bioassay. In these cases, with increasing dose of biologically active substance (BAS), the cellular response increases to a maximum (dose-response curve reaches a plateau). The most general schemes exhibiting this class of response can be classified as 3 classes:(I) BAS regulation of enzyme activity,(II) Ligand interaction with one type of receptor, and(III) Ligand interaction with negatively cooperative receptors.We will consider these three classes:(I): BAS might regulate enzyme activity. It might be:? substrate:E+S ←→ ES → E+P → cell response, (scheme 1)where E is enzyme, S is substrate, ES is enzyme-substrate complex, P is product. Cellular response is suggested to be proportional to product concentrat
Comparison of Biochemical and Bioassay Methods in Assessing Organophosphate Resistance in Blattella Germanica
M Abolhasani,M Shaeghi,H Ladonii
Journal of School of Public Health and Institute of Public Health Research , 2003,
Abstract: In this study we employed two methods for gauging the sensitivity of B. germanica strains to organophosphorus insecticides: an in-vivo bioassay that used linear regression analysis (with mortality on a probit scale and logarithm of concentration) and an in-vitro enzyme assay.In the bioassay method, B. germanica nymphs of stage 1 (2-3 days old) were exposed to patches of paper impregnated with 2% diazinon and propoxur. Compared to the sensitive (reference) strains, all but one of the tested strains showed resistance to diazinonzinon with resistance ratios of 0.97 to 1.67. As for propoxur, all strains were sensitive with the exception of one subject that showed a resistance ratio of 1.6. The enzyme assays used common esterase and acetylcholine esterase methods. Comparison of in-vivo and in-vitro tests on stage 1 nymphs of B. germanica shows that both methods are reasonably sensitive in measuring resistance/sensitivity ratios. In addition, the bioassay modality makes it possible to gauge the degree of insecticide sensitivity while the in-vitro method can only determine quantitative or qualitative changes in enzymes effected by carbamates and organophosphates. This study is the first of its kind, conducted by the school of Public Health in Tehran University of Medical Sciences.
Virtual screening of bioassay data
Amanda C Schierz
Journal of Cheminformatics , 2009, DOI: 10.1186/1758-2946-1-21
Abstract: Pharmaceutical bioassay data is not readily available to the academic community. The data held at PubChem is not curated and there is a lack of detailed cross-referencing between Primary and Confirmatory screening assays. With regard to the number of false positives that occur in the primary screening process, the analysis carried out has been shallow due to the lack of cross-referencing mentioned above. In six cases found, the average percentage of false positives from the High-Throughput Primary screen is quite high at 64%. For the cost-sensitive classification, Weka's implementations of the Support Vector Machine and C4.5 decision tree learner have performed relatively well. It was also found, that the setting of the Weka cost matrix is dependent on the base classifier used and not solely on the ratio of class imbalance.Understandably, pharmaceutical data is hard to obtain. However, it would be beneficial to both the pharmaceutical industry and to academics for curated primary screening and corresponding confirmatory data to be provided. Two benefits could be gained by employing virtual screening techniques to bioassay data. First, by reducing the search space of compounds to be screened and secondly, by analysing the false positives that occur in the primary screening process, the technology may be improved. The number of false positives arising from primary screening leads to the issue of whether this type of data should be used for virtual screening. Care when using Weka's cost-sensitive classifiers is needed - across the board misclassification costs based on class ratios should not be used when comparing differing classifiers for the same dataset.The drug-development process is both time-consuming and expensive: it takes an average of 15 years and $800 million to bring a drug to the market [1]. The process of discovering a new drug for a particular disease usually involves High-Throughput Screening (HTS), a mixture of robotics, control software, liquid-handl
Fundora,L. R; Cabrera,J. A; González,J; Ruiz,L. A;
Cultivos Tropicales , 2009,
Abstract: this work was developed in a cooperative production unit (ubpc) from ?camilo cienfuegos? agricultural enterprise, santa cruz del norte town, havana province, during 2005, which is geographically situated at 83° 10' n, 23° 10' w and 103 m over sea level, with the objective of studying the influence of the national phytostimulant fitomas-e combined with the biofertilizer ecomic? and mineral fertilization on sweet potato yield and other variables. six treatments were studied in the experiment employing the clone inivit b 98-2. results showed significant differences among treatments for those combinations studied, so proving crop answer to the combined application of phytostimulant, biofertilizers and mineral fertilization, besides obtaining yield increments of 50 % compared to the control. in general, this work showed that the combined application of phytostimulant fitomas-e with an efficient amf and 50 % mineral fertilization with npk improves crop development and yields under production conditions.
Review on Bioassay Technology of Endocrine Disrupting Pesticides

Han Zhihu,Bu Yuanqing,Shan Zhengjun,Cai Daoji,

生态毒理学报 , 2011,
Abstract: The endocrine disrupting pesticides are severely harmful to the health of human beings and other animals. Bioassay can be used to detect the hormone-like pesticides in the environment rapidly and conveniently. In this study, several common bioassay techniques of endocrine disrupting pesticides were reviewed, which can be generalized as in vivo assay, in vitro assay and non-cellular assay. The advantages and limitations of each method were discussed respectively, as well as their application in the evaluation of endocrine disrupting pesticides in the environment. This study aims to provide useful information for the development and application of bioassay techniques of endocrine disrupting pesticides in China.
Aggregating Behavior of Phenolic Compounds — A Source of False Bioassay Results?  [PDF]
Leena Pohjala,P?ivi Tammela
Molecules , 2012, DOI: 10.3390/molecules170910774
Abstract: Previous descriptions of quercetin, a widely studied flavonoid, as a frequently reported nonspecific screening hit due to aggregating behavior has raised questions about the reliability of in vitro bioactivity reports of phenolic compounds. Here a systematic study on 117 phenolic compounds is presented, concerning their aggregating tendency and the relevance of this phenomenon to obtaining false bioassay results. Fourteen compounds formed aggregates detectable by dynamic light scattering (DLS) when assayed at 10 μM in Tris-HCl pH 7.5. Flavonoids were more prone to aggregation than other phenolic compounds, and the aggregate formation was highly dependent on the vehicle, ionic strength and pH. The compounds were also assayed against three unrelated enzymes in the presence and absence of Triton X-100, and their bioactivity ratios were collected from PubChem database. By comparing these datasets, quercetin and rhamnetin were confirmed as promiscuous inhibitors. In general, flavonoids exhibited also higher bioactivity ratios in the PubChem database than coumarins or organic acids. To conclude, aggregate formation can be controlled with Triton X-100 and this phenomenon needs to be considered when bioassay data is interpreted, but our data indicates that it does not always lead to unspecific inhibition of biological targets.
Chronic toxicity bioassay with populations of the crustacean Artemia salina exposed to the organophosphate diazinon
Bustos-Obregon,Eduardo; Vargas,álvaro;
Biological Research , 2010, DOI: 10.4067/S0716-97602010000300013
Abstract: a chronic toxicity bioassay was conducted with the microcrustacean artemia salina as the testing organism for the toxic organophosphate diazinon in order to determine if the species is an appropriate indicator of pollution in aquatic environments. tests of animal exposure to different concentrations of the toxicant were performed for 24, 48 and 72 hours after larvae hatching. registered mortality data was used to obtain the lethal dose 50 (ld50) of the organophosphate for each exposure time, considering the immobilization of a. salina larvae as the mortality parameter. the lethal concentration (ld50) in the same exposure times was calculated by evaluating morphological changes on the three initial stages of larval development. both doses were determined by using probit statistical analysis. results indicate greater dose-response exactitude after 24 hours of exposure to the toxicant. high sensitivity of the organism to the toxicant was determined, thus indicating that a. salina is an appropriate ecotoxicological bioindicator of aquatic environments polluted with pesticides, with the special consideration that this species is a natural resident of saline water bodies, and thus could be used to control pollution in these environments as a result of the unrestrained usage of such toxic substances.
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