scholarly journals Susceptibility of Plutella xylostella (L.) to Bacillus thuringiensis Berliner strains

BioAssay ◽  
2021 ◽  
Vol 11 ◽  
pp. ba11001
Author(s):  
Cácia L. T. P. Viana ◽  
Sergio A. De Bortoli ◽  
Elizabeth C. Pedroso ◽  
Alessandra M. Vacari
Keyword(s):  
Bacillus Thuringiensis ◽  
Plutella Xylostella ◽  
Lethal Concentration ◽  
Susceptibility Pattern ◽  
High Susceptibility ◽  
Very High

The objective was to observe the susceptibility of a population of Plutella xylostella (L.) maintained for 100 generations in laboratory to strains of Bacillus thuringiensis Berliner. The concentrations 9×104, 1.5×105, 6×105, 8×105, 9×105, 1.5×106, 2×106, 3×106, 4.5×106, 6×106, 7.5×106, 9×106, 1.5×107, 2×107, 3×107, 4×107, 4.5×107, 6×107, 7.5×107, 9.5×107, 1.5×108 e 3×108 spores/mL were evaluated for the strains: E1, 49.30A, E2, 1.7L, T3A.259, T3A.140, T08024, E26, E22 and T07. The strains E26, E22 and T07 did not cause mortality for P. xylostella larvae. The P. xylostella larvae have a very high susceptibility pattern to the concentrations evaluated for six strains tested (E1, 49.30A, E2, 1.7L, T3A.259 and T3A.140). Only the T08.024 strain allowed the estimation of lethal concentration that kills 50% of the population (2.7 spores/mL).

scholarly journals Susceptibility of a Field-Derived, Bacillus thuringiensis-Resistant Strain of Diamondback Moth to In Vitro-Activated Cry1Ac Toxin

2001 ◽  
Vol 67 (9) ◽  
pp. 4372-4373 ◽  
Author(s):  
Ali H. Sayyed ◽  
Roxani Gatsi ◽  
Thaleia Kouskoura ◽  
Denis J. Wright ◽  
Neil Crickmore
Keyword(s):  
Bacillus Thuringiensis ◽  
Plutella Xylostella ◽  
Resistant Strain ◽  
Diamondback Moth ◽  
Resistance Mechanism ◽  
Lethal Concentration ◽  
Susceptible Population ◽  
Resistant Population ◽  
Susceptible Populations

ABSTRACT Resistant and susceptible populations of the diamondback moth (Plutella xylostella) were tested with crystalline, solubilized, and partially and fully activated forms of theBacillus thuringiensis Cry1Ac δ-endotoxin. Fully activated toxin greatly reduced the resistance ratio (ratio of the 50% lethal concentration for the resistant population to that for the susceptible population) of the resistant population, suggesting that a defect in toxin activation is a major resistance mechanism.

scholarly journals Markers of hikikomori in young people dur

2021 ◽  
pp. 70-74
Author(s):  
Inna Chuhueva ◽  
Viktoriia Sakovska
Keyword(s):  
Fast Food ◽  
Educational Activity ◽  
Psychological State ◽  
Defence Mechanism ◽  
High Susceptibility ◽  
New Era ◽  
Long Time ◽  
Definition Of ◽  
The Impact ◽  
Very High

The article summarizes the definition of the term “hikikomori”, analyzes the situation of quarantine restriction: its essence and features of the impact on adolescence. Peculiarities of manifestation of hikikomori markers at adolescence are determined. We consider the studied phenomenon in the system of approaches like a way to meet needs, as a set of manifestations of syndromes of a new era, as a psychological defence mechanism, as a psychological state and process. Depending on the intensity of markers, we divide hikikomori into counter-dependent, poorly adaptable and interdependent, super dependent. The parameters that determine the level of manifestations of hikikomori include antisocial solitude at home, antisocially with leaving the house, selective society. The levels of manifestation of hikikomori include physical, emotional, social. Quarantine restrictions, as unusual living conditions that require forced solitude, selfisolation can be a factor that encourages the emergence of markers of hikikomori in adolescents. Such people have a shift in activity in cyberspace and at night, inseparable stay with the gadget (during meals, in the bathroom, in the toilet, etc.). Neglect of the organization of life (do not clean the bed after sleep, do not clean the room for a long time, do not change clothes during the day and wear night pyjamas around the clock, neglect a healthy diet, eat outside the regime, mostly fast food, etc.). In communication with others, they show irritability with the desire to avoid contact and solitude in their room. Also, at such a person, disorganization of educational activity hastily is observed. It is difficult for them to organize the learning process; they show procrastination (postponement of tasks). If the classes are as videoconferencing, they do not include video and microphone. They are away from contact with the group and the teacher, even if they need contact for feedback, they ignore it. An empirical study of the susceptibility to hikikomori markers in adolescents revealed that about 40% of subjects have a high susceptibility to hikikomori markers, and almost 11% of young men – very high.

scholarly journals Susceptibilidad a la licuación de suelos y sedimentos en el valle Ullum-Zonda (31º30’ S-68º25’ O), Precordillera, Andes Centrales, Argentina

2021 ◽  
Vol 48 (2) ◽  
pp. 333
Author(s):  
Silvia Palacios ◽  
Gabriela Lara ◽  
Laura Perucca
Keyword(s):  
Industrial Sector ◽  
Distal Portion ◽  
Alluvial Fan ◽  
San Juan ◽  
Historical Records ◽  
High Susceptibility ◽  
Conditioning Factors ◽  
Sedimentary Deposits ◽  
San Juan River ◽  
Very High

. The earthquakes of 1894, 1944, 1952 and 1977 occurred in the province of San Juan in central-wesern Argentina caused numerous processes of soils and sediment liquefaction, including those in the Ullum-Zonda valley. Historical records showed cracks, sand volcanoes, craters and differential settlements, which caused significant damage to housing and the agro-industrial sector of the region. In this work, we carried out a study of the susceptibility to liquefaction of soils and sedimentary deposits in the Ullum-Zonda valley. This was conducted using a methodology in which conditioning factors such as depth of the water table, historical records of liquefaction, potential seismogenic sources, origin, age and grain size of the soils and sedimentary deposits, among others, were evaluated and weighted. An iterative process of overlapping maps weighted the influence of the different factors in the assessment of susceptibility. Once the optimal combination was achieved, a final map with the zoning of soils and sediment susceptibility to liquefaction was obtained for the Ulum-Zonda Valley. The achieved zoning was related to a susceptibility index (SI), qualitatively classified as very high, high, moderate and low. The zone of very high susceptibility to liquefaction is located in the distal portion of the alluvial fan formed by the San Juan River in the Ullum-Zonda Valley, the areas of high to moderate susceptibility in the middle sector of the fan, and those of moderate to low susceptibility correspond to the proximal-middle sector of the fan. The main villages of the Ullum-Zonda valley, Ibáñez (head of the Ullum department) to the north of the San Juan River, Basilio Nievas (head of the Zonda department), to the south of the river, Tacú residential sector (located south of the Ullum dam) and the yacht clubs (located on the northeast periphery of the dam) are located in the areas of high to very high susceptibility, where the main conditioning factors are soil and sediments granulometry and the depth of the phreatic level.

The initial stages in the action of an insecticidal delta-endotoxin of Bacillus thuringiensis var. israelensis on the epithelial cells of the malpighian tubules of the insect, Rhodnius prolixus

1988 ◽  
Vol 90 (1) ◽  
pp. 131-144
Author(s):  
S.H. Maddrell ◽  
N.J. Lane ◽  
J.B. Harrison ◽  
J.A. Overton ◽  
R.B. Moreton
Keyword(s):  
Bacillus Thuringiensis ◽  
Intercellular Junctions ◽  
Fluid Secretion ◽  
Malpighian Tubules ◽  
Ultrastructural Changes ◽  
Cytoplasmic Vacuolization ◽  
Large Numbers ◽  
Delta Endotoxin ◽  
High Concentrations ◽  
Very High

The effects of the 27 X 10(3) Mr insecticidal delta-endotoxin from Bacillus thuringiensis var. israelensis have been studied using, as a model system, isolated insect Malpighian tubules. At all concentrations of the toxin higher than 1 microgram ml-1 (4 X 10(−8) moll-1) applied to the outer surface of the tubules, fluid secretion failed within about 30 min. Except at very high concentrations, where failure always takes at least 30 s, there was an inverse relationship between the concentration of toxin and the time of failure of toxin-treated tubules. During exposure to toxin, the tubules were initially unaffected for a relatively long period and then rapid failure occurred. If the tubules were removed into toxin-free saline just before failure would have occurred, fluid secretion remained normal for at least 2 h, but on return to the origin toxin-containing saline failure was almost immediate. The toxin was found not to bind to the basement membrane. Ultrastructural changes became evident as tubule failure occurred. These initially involved modifications to the basal side of the cells, but later also to the luminal microvilli. Intercellular junctions became disassociated and cytoplasmic vacuolization occurred. The population of intramembranous particles in the basal membranes became reduced with time. Our findings suggest the following hypothesis for the initial stages in the interaction of the toxin with the tubules. Toxin molecules attach to the accessible cell membranes progressively and irreversibly. They do not readily associate by diffusing laterally in the membrane, so that toxic effects develop only when sufficiently large numbers of them attach close together. The molecules may then associate in some way as a complex, perhaps forming a pore in the membrane. Relatively few such pores lead rapidly to cell failure and death.

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