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Abstract A series of N-4 piperazinyl ciprofloxacin derivatives as urea-tethered ciprofloxacin-chalcone hybrids 2a-j and thioacetyl-linked ciprofloxacin-pyrimidine hybrids 5a-i were synthesized. The target compounds were investigated for their antibacterial activity against S. aureus, P. aeruginosa, E. coli, and C. albicans strains, respectively. Ciprofloxacin derivatives 2a-j and 5a-i revealed broad antibacterial activity against either Gram positive or Gram negative strains, with MIC range of 0.06–42.23 µg/mL compared to ciprofloxacin with an MIC range of 0.15–3.25 µg/mL. Among the tested compounds, hybrids 2b, 2c, 5a, 5b, 5h, and 5i exhibited remarkable antibacterial activity with MIC range of 0.06–1.53 µg/mL against the tested bacterial strains. On the other hand, compounds 2c, 2e, 5c, and 5e showed comparable antifungal activity to ketoconazole against candida albicans with MIC range of 2.03–3.89 µg/mL and 2.6 µg/mL, respectively. Further investigations showed that some ciprofloxacin hybrids have inhibitory activity against DNA gyrase as potential molecular target compared to ciprofloxacin with IC50 range of 0.231 ± 0.01–7.592 ± 0.40 µM and 0.323 ± 0.02 µM, respectively. Docking studies of compounds 2b, 2c, 5b, 5c, 5e, 5h, and 5i on the active site of DNA gyrase (PDB: 2XCT) confirmed their ability to form stable complex with the target enzyme like that of ciprofloxacin. Graphical abstract

The lower Eocene-lower Miocene succession in the central part of the Al Jabal Al Akhdar, northeast Libya was investigated to determine its depositional environments and shed some light on diagenetic alterations. This succession is composed mainly of carbonate rocks and includes five formations from base to top; the Apollonia, Darnah, Al Bayda, Al Abraq, and Al Faidiyah. Relatively uniform shallow-marine carbonates were accumulated across northeast Libya, including the study area. Facies analysis of the studied carbonate rocks enables determination of four shallow-marine carbonate facies associations. These facies associations are: (1) restricted lagoon with limited circulation at/or below fair-weather wave base, (2) lagoon with open circulation below the fair-weather wave base, (3) platform-margin reefs, and (4) continental slope setting between the fair-weather and storm wave bases. The abundance of shallow marine carbonates indicates the presence of epeiric or epicontinental sea that covered the whole northern Africa. The depositional history in the studied area was controlled primarily by tectonics and relative sea-level changes. Four unconformities (i.e., sequence boundaries) were observed and separating five depositional sequences in the studied succession. Each depositional sequence shows shallowing-upward trend. The recorded unconformities reflect episodes of non-deposition and/or erosion and are associated with major fall in eustatic sea level. The diagenetic processes of the studied carbonate rocks include; micritization, pyritization, compaction, cementation, aggrading neomorphism and partial dissolution.

Background Varroa mite, Varroa destructor Anderson and Trueman (Parasitiformes: Varroidae), is an ectoparasitic mite of the honey bee, Apis mellifera L. (Hymenoptera: Apidae), with a great economic importance. It is the major deadlock of apiculture development all over the world. Results This work aimed to assess the effect of bee house and dark bee house on numbers of Varroa mite on white card board sheets, worker broods, and alive bees during spring and autumn of 2018 and 2019. Two types of card board for sticking the fallen Varroa mite were evaluated through winter of 2019. Keeping honey bee hives in a dark room during March and September of 2018 and 2019 for a successive 3 days resulted in a great reduction in the number of Varroa inner bee hive, i.e., on the white card board sheets, area of broods, and alive honey bee. Highest number of fallen Varroa mite on the white card board sheets was obtained in the case of using the dark bee house during March and September in 2018 and 2019, followed by keeping in a normal bee house then those fallen in the case of the open apiary. Conclusion The dark bee house grooming behaviour increased through 3 days of dark. Environmental management of bee house and dark bee house can be promising in colony collapse disorder. Modified adhesive sheets were more efficient in this regard than the normal ones.