The study of the functional morphology of the reproductive system of trematodes, as well as its individual parts, provides an opportunity to solve an important problem that plays a huge role in theoretical and practical terms as the directed regulation of the fecundity of endoparasites. The article is devoted to the study of the functional role of vitelline glands and Mehlis glands in the process of formation of resistant egg shells on the example of the Parastrigea robusta trematode. The functional mechanisms are revealed on the basis of histomorphological and ultrastructural studies, underlying the provision of trematode eggshell formation processes and the role of each of the mentioned departments. The sequence of appearance and maturation of shell material in the vitelline follicles during vitellogenesis has been determined. The role of the Mehlis gland is substantiated on the basis of electron microscopy methods and their functional morphological analysis of ultrastructural and micromorphological data. The obtained data reveals information on the structural and functional unity of the mechanisms underlying the formation of a resistant trematode eggshell, the role of vitelline glands, and Mehlis gland in providing a "large number of eggs". According to the results of histological and electron microscopic studies of vitelline glands and Mehlis gland of the Parastrigea robusta trematode, a general scheme of the formation of trematode eggshell was formed. As a result, the obtained knowledge on the peculiarities of the structure and maturation of the vitelline glands and Mehlis gland of Parastrigea robusta will significantly complement the knowledge on the structural features of the female reproductive system of trematodes and the fertility of endoparasites. The results of the work can be used for further research in the selection of anthelmintic agents that affect vitelline glands and Mehlis glands, which will lead to directed regulation of the fertility level of endoparasites.
Zeolite materials are among the relatively cheap and readily available materials for wastewater treatment. However, the performance of zeolite-based systems can be highly affected by the material properties. In this study, the treatment system based on natural zeolite materials from Chankanai mines in Kazakhstan was compared with a synthetic zeolite treatment system for the purification of groundwater. Water quality indices were also developed from a set of selected water quality parameters to further assess the state of water quality of raw groundwater and the effluents treated with natural and synthetic zeolite. The lowest removal efficiency of natural zeolite (30%) was observed with zinc, while the lowest removal efficiency (36%) of synthetic zeolite was observed with arsenic. With turbidity and beryllium, we observed the maximum removal efficiency (100%) of natural zeolite, whereas with turbidity, we observed the highest removal efficiency (100%) of synthetic zeolite. When the groundwater samples were put through the natural zeolite treatment system, removal efficiency of 50% and above was obtained with 27 (79.4%) out of the 34 water quality parameters examined. On the other hand, when the groundwater samples were put through the synthetic zeolite treatment system, more than 50% removal efficiency was attained with 30 (88.2%) out of the 34 water quality parameters studied. The aggregated water quality index of raw groundwater was 3278.24, falling in the “water unsuitable for drinking” category. The effluent treated with natural zeolite generated 144.82 as a water quality index, falling in the “poor water” quality category. Synthetic zeolite generated 94.79 as a water quality index, falling in the “good water” quality category. Across the board, it was shown that the synthetic zeolite treatment system outperformed the natural zeolite treatment system according to a number of water quality parameters. The findings of this study offer substantial knowledge that can be used to develop more efficient groundwater treatment technologies.
The forests of Central Asia are biodiversity hotspots at risk from rapid climate change, but they are understudied in terms of the climate–growth relationships of trees. This classical dendroclimatic case study was performed for six conifer forest stands near their semiarid boundaries across Kazakhstan: (1–3) Pinus sylvestris L., temperate forest steppes; (4–5) Picea schrenkiana Fisch. & C.A. Mey, foothills, the Western Tien Shan, southeast; (6) Juniperus seravschanica Kom., montane zone, the Western Tien Shan, southern subtropics. Due to large distances, correlations between local tree-ring width (TRW) chronologies are significant only within species (pine, 0.19–0.50; spruce, 0.55). The most stable climatic response is negative correlations of TRW with maximum temperatures of the previous (from −0.37 to −0.50) and current (from −0.17 to −0.44) growing season. The strength of the positive response to annual precipitation (0.10–0.48) and Standardized Precipitation Evapotranspiration Index (0.15–0.49) depends on local aridity. The timeframe of climatic responses shifts to earlier months north-to-south. For years with maximum and minimum TRW, differences in seasonal maximal temperatures (by ~1–3 °C) and precipitation (by ~12–83%) were also found. Heat stress being the primary factor limiting conifer growth across Kazakhstan, we suggest experiments there on heat protection measures in plantations and for urban trees, alongside broadening the coverage of the dendroclimatic net with accents on the impact of habitat conditions and climate-induced long-term growth dynamics.
Major losses of fresh tomatoes happen during post-harvest storage due to prompt senescence and diseases. The aim of the research was to evaluate the effects of different spectra of LED lights on the post-harvest preservation of ascorbic acid, lycopene, and total soluble solids, the weight and size of tomato fruits, as well as to determine the optimal exposure time and distance of irradiation and extension of shelf-life. Therefore, experiments were carried out in a climate chamber with shelves equipped with three different light spectra: red light-emitting diodes, red–blue–white light-emitting diodes, and ultraviolet-light-emitting diodes. Light treatment had a certain positive effect on the firmness, size, and mass of samples. Thus, tomato fruits (Panekra) exposed to the spectra of LED lights demonstrated a better quality of firmness and mass compared to the control samples (non-preserved) of tomatoes. The treatments with RL significantly improved the concentration of lycopene than FL and UV-LED lights, although the highest concentration of lycopene was observed in the control samples for the first 7 days of the storage. After 21 days, the ascorbic acid content in the red spectrum was found to be much higher than in the other two spectra and control samples, coming in at about 1.8 mg/100 mL compared to 1.0 mg/100 mL for the control samples. Total soluble solids also increased significantly after preservation, rising from 3.9 °Brix in the control samples to roughly 7.3 °Brix in samples preserved using the full spectrum after 21 days. Overall, the results of the study demonstrated that tomato preservation using the investigated techniques induced lycopene concentration, ascorbic acid, and total soluble solids concentrations. The results derived from this study provide highly useful information in the field of post-harvest preservation.
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