RELATIVE TOXICITY OF SOME CHEMICAL PESTICIDES AGAINST JUTE HAIRY CATERPILLAR (SPILOSOMA OBLIQUA W.) IN TOSSA JUTE (CORCHORUS OLITORIUS L.)

Pesticides have been a major contributor to the growth of agricultural productivity and food supply. Pesticides were a key factor in significant agricultural productivity growth during the last century and continue to be a critical factor in reducing crop damage. Fifteen insecticides were investigated to select their effective and economic doses against Hairy caterpillar in a Tossa Jute variety during April-October’ 2020 at the Department of Entomology, Manikganj and Narayanganj, Bangladesh Jute Research Institute (BJRI), Bangladesh following Randomized Completely Block Design with three replications. All new insecticides with a standard were found effective for controlling jute hairy caterpillar giving 95.38, 94.55, 95.19, 92.85, 93.59, 94.22, 93.49, 93.62, 89.84, 95.72, 93.56, 93.38, 94.42, 95.39, 91.34 and 95.41 % at Manikganj; 95.78, 93.32, 93.97, 93.18, 92.09, 92.49, 93.74, 92.93, 92.29, 93.69, 93.95, 93.17, 95.31, 94.99, 92.11 and 94.53 % reduction of infestation at Narayanganj at 5th day after spray over control plot respectively. In Manikganj, the highest fibre yield (3.66 t/ha) was found in the plot treated with Rock 20 EC and the lowest (2.96t/ha) was found in Reset 20WDG treated plot. In case of Narayanganj, the highest fibre yield (3.85 t/ha) was found in the plot treated with Proxy 20 EC and the lowest (2.79t/ha) was found in Daman treated plot. These insecticides can be recommended for the farmer’s use to control jute hairy caterpillar.

DETERMINATION OF CHEMICAL AND TOXICOLOGICAL CHARACTERISTICS OF WATER QUALITY IN RECREATIONAL AREAS ON THE MATYRA RIVER

В работе приведены и проанализированы данные химических и токсикологических исследований воды р. Матыра Липецкой области. Отмечены превышения допустимых значений по органолептическим показателям, а также по сульфатам, аммоний-иону и нитритам. Кроме того, было проведено определение относительной токсичности с помощью метода, основанного на регистрации изменений оптической плотности культуры водоросли хлорелла ( Chlorella vulgaris ). В результате биотестирования показано, что все пробы воды проявили токсичность, которая проявляется в стимуляции роста культуры хлорелла. Такая стимуляция роста свидетельствует о том, что исследованные пробы содержат легкоусвояемые органические и неорганические соединения. При сравнении полученных значений концентраций с предыдущими исследованиями отмечена отрицательная динамика по всем определяемым загрязняющим веществам, что свидетельствует о снижении качества воды. The paper presents and analyzes the data of chemical and toxicological studies of the water of the Matyra river of the Lipetsk region. Excess of permissible values for organoleptic parameters, as well as for sulfates, ammonium ion and nitrites were noted. In addition, the relative toxicity was determined using a method based on the registration of changes in the optical density of the Chlorella (Chlorella vulgaris) algae culture. The results of the bioassay showed that all water samples demonstrated toxicity, which manifests itself in stimulating the growth of chlorella culture. Such growth stimulation indicates that the samples studied contain easily digestible organic and inorganic compounds. When comparing the obtained concentration values with previous studies, negative dynamics was noted for all identified pollutants, which indicates a decrease in water quality.

AI Informed Toxicity Screening of Amine Chemistries used in the Synthesis of Hybrid Organic-Inorganic Perovskites

This paper describes a machine learning guided framework for screening the potential toxicity impact of amine chemistries used in the synthesis of hybrid organic-inorganic perovskites. Using a combination of a probabilistic molecular fingerprint technique that encodes bond connectivity (MinHash) coupled to non-linear data dimensionality reduction methods (UMAP), we develop an “Amine Atlas’. We show how the Amine Atlas can be used to rapidly screen the relative toxicity levels of amine molecules used in the synthesis of 2D and 3D perovskites and help identify safer alternatives. Our work also serves as a framework for rapidly identifying molecular similarity guided, structure-function relationships for safer materials chemistries that also incorporate sustainability/ toxicity concerns.

Assessing the Relative Toxicity of Different Road Salts and Effect of Temperature on Salinity Toxicity: LCx Values vs. No Effect Concentration (NEC) Values

Freshwater biota are at risk globally from increasing salinity, including increases from deicing salts in cold regions. A variety of metrics of toxicity are used when estimating the toxicity of substances and comparing the toxicity between substances. However, the implications of using different metrics is not widely appreciated. Using the mayfly Colobruscoides giganteus (Ephemeroptera: Colobruscoidea) we compare the toxicity of seven different salts where toxicity was estimated using two metrics 1) the no effect concentrations (NEC) and 2) the lethal concentrations for 10, 25 and 50% of the test populations (LCx). The LCx values were estimated using two different models, the classic log-logistic model and the newer toxicokinetic-toxicodynamic (TKTD) model. We also compare the toxicity of two salts (NaCl and CaCl2) for C. giganteus at water temperatures of 4°C, 7°C and 15°C using the same metrics of toxicity. Our motivation for using a mayfly to assess salinity toxicity was because mayflies are generally salt sensitive, are ecologically important and are common in Australian (sub-)alpine streams. Considering 144-hour LCx values, we found toxicity differed between various salts, i.e., the lowest 144-hour LC50 (8 mS/cm) for a salt used by a ski resort was half that of the highest 144-hour LC50 from artificial marine salts and CaCl2 applied to roads (16mS/cm). 144-hour LC50 results at 7°C showed that analytical grade NaCl was significantly more toxic (7.3mS/cm) compared to analytical grade CaCl2 (12.5mS/cm). Yet for NEC values, there were comparably fewer differences in toxicity between salts and none between the same salts at different temperatures. We conclude that LCx values are better suited to compare difference in toxicity between substances or between the same substance at different test temperatures, while NEC values are better suited to estimating concentrations of substances that have no effect to the test species and endpoint measured under laboratory conditions.

Behavioural Responses and Mortality of Clarias gariepinus Juveniles Exposed to Acute Concentrations of Paraquat

Paraquat is the most common contact and non- selective herbicide for exterminating vegetative pest. Fish are ideal sentinels for detecting aquatic pollutants and are largely used as bio indicators of environmental pollution. This study is aimed to determine the behavioural changes, lethal concentrations (LCs) and mean lethal time (MLT) of paraquat exposed to Clarias gariepinus. A 96 hours renewable bioassay was conducted with various paraquat concentrations 0.0, 0.25, 0.50, 0.75, 1.0 and 1.25 mg/l. Behavioural changes and cumulative mortality were observed and recorded at 12, 24, 48, 72 and 96 hour. Behavioural changes such as air gulping, erratic swimming, loss of balance, excessive mucus secretion, discolouration and death were observed with severity increasing as concentration and duration of exposure increases. The LC50 values were decreased from 0.191mg/l (0.171 – 0.222) in 12 hour to 0.107mg/l (0.065 – 0.150) in 96 hour, while relative toxicity factor (TF) was increased from 1 to 1.79 times respectively. The 96hr MLT values were decreased from 91.18 hours (54.09-105.64) at the lowest concentration to 16.22 hours (9.06 – 25.15) at the highest concentration with relative toxicity time (RTT) increasing from 1 to 5.62 times. Herbicide should be apply with caution and studies on the sub lethal effects of paraquat on the haematological, biochemical and histological parameters of C. gariepinus juveniles will be necessary.