Antibacterial activity and cytotoxicity of extractives from Uvaria hamiltonii stem bark

The extracts as well as piperolactum C, goniopedaline, 6beta-hydroxystigmasta-4,22-dien-3-one and a mixture of cis- and trans-4-hydroxymelleins obtained from Uvaria hamiltonii stem bark exhibited mild to moderate in vitro antibacterial activity. The results obtained were compared with a standard antibiotic, kanamycin. In a brine shrimp lethality bioassay the pet-ether, dichloromethane, methanol extracts and a major alkaloid, piperolactum C were found to exhibit mild to moderate cytotoxicity.     

Scale insect pests on ornamental plants in urban habitats in Turkey

Ornamental plants play an increasingly important role in urban habitats in Turkey. Scale insects are a serious pest group that attack ornamental plants. In this study, a total of 67 species of Coccoidea belonging to 7 families, which are harmful to ornamental plants, are given in Tables 1, 2, and 3. These tables are based on the authors data and on bibliographic sources. The most numerous families are Diaspididae (31), Coccidae (23), Pseudococcidae (7), Eriococcidae (3), and the Margarodidae, Kermesidae and Astereolecaniidae (1). Twenty-one of these species are harmful to flowering fruit and deciduous trees, 5 species are harmful to conifers, while 15 species are important orchard pests. Their hosts and distributions are also taken into consideration.     

Über das Vorkommen von Blattlausarten(Aphidoidea) im türkischen Forst

Zusammenfassung Die Aphiden in den türkischen Forsten (114 Arten in 7 Familien) und deren Wirtspflanzen sowie ihre ö konomische Bedeutung sind in diesem Artikel zusammengestellt. Die wichtigsten Arten sind.Pineus orientalis (Dreyf.),P. pini (Macq.) (Adelgidae);Cinara cedri Mime.,C. palaestinensis H. R. Lamb. (Lachidae);Eriosoma lanuginosum (Hart.) (Pemphigidae);Phyllaphis fagi (L.) (Callaphidae) undAphis craccivora Koch (Aphididae).Weitere in den türkischen Wäldern verbreitete Blattlausarten können orts- und zeitweise von Bedeutung sein.

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Summary The aphids of Turkish forests (114 species in 7 families), their host plants and economic importance are summarized. More important species are:Pineus orientalis (Dreyf.),P. pini (Macq.) (Adelgidae);Cinara cedri Mim.,C. palaestinensis H. R. Lamb. (Lachnidae);Eriosoma lanuginosum (Hart.) (Pemphigidae);Phyllaphis fagi (L.) (Callaphididae) andAphis craccivora Koch (Aphididae).The other aphids which are recorded in Turkish forest, in some extent are important species.

     

Insecticide resistance compromises the control of Aedes aegypti in Bangladesh

BACKGROUND

With no effective drugs or widely available vaccines, dengue control in Bangladesh is dependent on targeting the primary vector Aedes aegypti with insecticides and larval source management. Despite these interventions, the dengue burden is increasing in Bangladesh, and the country experienced its worst outbreak in 2019 with 101 354 hospitalized cases. This may be partially facilitated by the presence of intense insecticide resistance in vector populations. Here, we describe the intensity and mechanisms of resistance to insecticides commonly deployed against Ae. aegypti in Dhaka, Bangladesh.

RESULTS

Dhaka Ae. aegypti colonies exhibited high-intensity resistance to pyrethroids. Using CDC bottle assays, we recorded 2–24% mortality (recorded at 24 h) to permethrin and 48–94% mortality to deltamethrin, at 10× the diagnostic dose. Bioassays conducted using insecticide–synergist combinations suggested that metabolic mechanisms were contributing to pyrethroid resistance, specifically multi-function oxidases, esterases, and glutathione S-transferases. In addition, kdr alleles were detected, with a high frequency (78–98%) of homozygotes for the V1016G mutation. A large proportion (≤ 74%) of free-flying and resting mosquitoes from Dhaka colonies survived exposure to standard applications of pyrethroid aerosols in an experimental free-flight room. Although that exposure affected the immediate host-seeking behavior of Ae. aegypti, the effect was transient in surviving mosquitoes.

CONCLUSION

The intense resistance characterized in this study is likely compromising the operational effectiveness of pyrethroids against Ae. aegypti in Dhaka. Switching to alternative chemical classes may offer a medium-term solution, but ultimately a more sustainable and effective approach to controlling dengue vectors is required. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Reducing Marble-SO2 Reaction Rate by the Application of Certain Surfactants

Sulfur dioxide (SO₂), prevalent in the modern urban environment of industrial countries, attacks calcite (CaCO₃)in marble. As a result, a gypsum (CaSO₄·2H₂O) crust is produced at rain-sheltered surfaces while areas exposed to rain experience accelerated erosion. We have investigated theeffect of certain surfactants as protective agents against SO₂ attack. We report that the anions oxalate (C₂O₄ ^-2) and oleate (C₁₇H₃₃COO^-) from solutions of their highly soluble alkali salt species areable to replace carbonate (CO₃ ^-2) in calcite producingless reactive substrate of oxalate and oleate of calcium. Experiments to measure the protection obtained by these treatments were carried out in the laboratory and field conditions at nearly 1ppm and 10 ppb SO₂ concentrations, respectively. We found that these treatments provided significantprotection to marble exposed in sheltered areas, up to 30% reduction of reaction rate by treatment with 2 × 10^-4M sodium oleate and up to 14% by a 2 × 10^-3 M with potassium oxalate solutions, but become ineffective over long term exposure when applied to surfaces exposed to rain.Carrara marble was used in the reported study. Ion chromatographywas the analytical tool, which allowed precise measurements of ionic concentrations of these salts, the amount of their uptakeby marble, and the thickness of the gypsum crust. X-ray diffraction allowed determination of the new minerals formed at the marble surface by the treatment with surfactants.     

Antitumor activity of epifriedelanol from Vitis trifolia.

The isolation and NMR spectral data of epifriedelanol from Vitis trifolia are reported. It demonstrated antitumor activity in a potato disc bioassay.     

Changes in luteinizing hormone-containing gonadotrophs after moulting induced by fasting and zinc in laying hens (Gallus domesticus)

The purpose of the present study was to investigate egg production performance, immunohistochemical (IHC) identification, localization and morphological characterization of moulted hen’s pars distalis luteinizing hormone (LH) gonadotrophs. This system has been validated for chicken LH by immunodetection of purified hormones on dot blots, western blotting and by specific labelling of cells on sagittal sections of chicken pituitaries. This study showed that egg production and egg weight increased significantly after zinc-induced moult when compared with fasting-induced moult. Luteinizing hormone-gonadotrophs are of numerous shapes and distributed throughout the adenohypophysis, with densely populated regions on the margins of pars distalis. Moulting of laying hens was associated with a significant increase in immunoreactive LH gonadotroph cell count and cell size, which peaked at the subsequent production stages. Zinc-induced moulting also caused a significant increase in LH gonadotroph cell size as compared with fasting-induced moulting. The nuclear size of LH-positive cells was distinct during decreased egg production. Our results validate the use of ovine LHβ antibodies for the IHC localization of chicken LH gonadotrophs. This technology was further applied to the characterization of the shape and morphological changes of gonadotrophs as a function of the egg production status of the birds.