High-resolution quantitative analysis of the benthonic foraminifera throughout the K–Pg boundary interval on four sections (Wadi Nukhul, Abu Qada, Thamad, and Sudr Al Hitan) in south Sinai, Egypt was conducted. Planktonic foraminiferal biostratigraphy indicates a complete K–Pg boundary interval in W. Nukhul section, while minor hiatuses characterized the other sections. Benthonic foraminifera reflect outer neritic-upper bathyal setting for the studied interval, while outer neritic setting marks the latest Maastrichtian. The upper Maastrichtian assemblage indicates mesotrophic to slightly eutrophic marine conditions. At the K–Pg boundary in W. Nukhul, benthonic foraminifera display a significant turnover. A major change in the benthonic foraminifera assemblage which is marked by a decrease in the infaunal taxa and buliminids indicates a shortage in the food supply to the sea floor at the K–Pg boundary. This pattern was associated with increased abundance of the epifaunal taxa indicating oligotrophic conditions that linked to the food web collapse due to extinction of the marine primary producers. A partial recovery of the benthonic foraminifera was observed in the early Danian (Pα and lower part of P1a zones). A comparison between the data of the present study and other K–Pg boundary sites in the Tethyan realm indicates a similar shortage in the food supply with no oxygen deficiency. Two third-order sequences were identified in the studied interval based on the biotic attributes of the fauna. The obtained sea level curve was compared to the global sea level curve.

Background

Agriculture crops such as tomatoes and wheat are frequently targeted by insect pests which have a significant negative impact on the agricultural economies. The deployment of entomopathogenic fungi (EPF) for the control of the insect pests is an important alternative to synthetic insecticides. The EPF, Beauveria bassiana (Balsamo) Vuillemin, has been reported widely as a suitable biological control agent of many agricultural pests.

Results

In this study, B. bassiana SS-1 was isolated from local plant crops and its pathogenicity was assessed against the greater wax moth larvae Galleria mellonella (L.). The development of the pathogenic B. bassiana SS-1 on the insect was visualized using scanning electron microscopy (SEM). Results showed the ability of B. bassiana SS-1 to secrete extracellularly the important enzymes essential for insect cuticle penetration. B. bassiana SS1 recorded the maximum mean lipase (5.3 U/ml), protease (32.13 U/ml), and chitinase activities (2.95 U/ml). The endophytic pathogenic fungus B. bassiana SS-1 demonstrated pathogenicity against the fourth instar larvae of G. mellonella showing LC₅₀ at 2.47 × 10² conidia/ml and LC₉₅ at 3.98 × 10⁵ conidia/ml. The SEM results showed physical contact with B. bassiana SS-1 hyphae on the surface of the G. mellonella larvae. Thus, the isolated EPF B. bassiana SS-1, even endophytic, could be a promising biocontrol agent to manage agricultural insect pests.

Conclusion

This study provided a comprehensive characterization of the pathogenicity of B. bassiana SS-1 with its microbiological characteristics. Future studies are needed to focus on the detection of highly virulent isolates against different insect pests and to assess their field contribution as a favorable biological control agent.

Aim: We aimed to investigate the potential inhibitory effects of diterpenes on SARS-CoV-2 main protease (Mpro). Materials & methods: We performed a virtual screening of diterpenoids against Mpro using molecular docking, molecular dynamics simulation and absorption, distribution, metabolism and excretion) analysis. Results: Some tested compounds followed Lipinski’s rule and showed drug-like properties. Some diterpenoids possessed remarkable binding affinities with SARS-CoV-2 Mpro and drug-like pharmacokinetic properties. Three derivatives exhibited structural deviations lower than 1 Å. Conclusion: The findings of the study suggest that some of the diterpenes could be candidates as potential inhibitors for Mpro of SARS-CoV-2.

The present paper is devoted to study some completeness properties of transitive binary relational set, i.e., a set together with a transitive binary relation (so called t-set). We hope that the results of our paper will be a starting  point for a sufficiently general but simple theory of objects that are suitable for modelling various aspects of  computation and useful in modern applications of domain theory to general topology and mathematical analysis.

http://dx.doi.org/10.18642/jmsaa_7100122266

This work is licensed under the Creative Commons Attribution International License (CC BY 3.0).
http://creativecommons.org/licenses/by/3.0/deed.en_US

This paper aims to define fuzzy pretopogenous structure based on way below relation (or an L-fuzzifying pretopogenous structure (LFPT structure, for short)) and study some of its properties. Also, the concepts of L-fuzzifying pre-neighborhood, L-fuzzifying pre-interior, and L-fuzzifying pre-closure operators are established and we used these concepts to build an L-fuzzifying topology. Furthermore, a natural link is established between L-fuzzifying pretopogenous and L-fuzzifying topology. Finally, the maps between L-fuzzifying pretopogenous structures and initial fuzzifying structures are investigated.

https://doi.org/10.2298/FIL2319427S