Surface water quality, public health, and ecological risks in Bangladesh-a systematic review and meta-analysis over the last two decades.

Water quality has recently emerged as one of the utmost severe ecological problems being faced by the developing countries all over the world, and Bangladesh is no exception. Both surface and groundwater sources contain different contaminants, which lead to numerous deaths due to water-borne diseases, particularly among children. This study presents one of the most comprehensive reviews on the current status of water quality in Bangladesh with a special emphasis on both conventional pollutants and emerging contaminants. Data show that urban rivers in Bangladesh are in a critical condition, especially Korotoa, Teesta, Rupsha, Pashur, and Padma. The Buriganga River and few locations in the Turag, Balu, Sitalakhya, and Karnaphuli rivers have dissolvable oxygen (DO) levels of almost zero. Many waterways contain traces of NO3, NO2, and PO4-3 pollutants. The majority of the rivers in Bangladesh also have Zn, Cu, Fe, Pb, Cd, Ni, Mn, As, and Cr concentrations that exceed the WHO permissible limits for safe drinking water, while their metal concentrations exceed the safety threshold for irrigation. Mercury poses the greatest hazard with 90.91% of the samples falling into the highest risk category. Mercury is followed by zinc 57.53% and copper 29.16% in terms of the dangers they pose to public health and the ecosystem. Results show that a considerable percentage of the population is at risk, being exposed to contaminated water. Despite hundreds of cryptosporidiosis cases reported, fecal contamination, i.e., Cryptosporidium, is totally ignored and need serious considerations to be regularly monitored in source water.

Pollen morphology of selected melliferous plants and its taxonomic implications using microscopy.

This research aimed to explore the melliferous bee flora pollen from arid zones of District Attock, Islamabad Capital and Rawalpindi. Morpho-palynological features has provided key information for the classification and help to explain the taxonomy of several genera and species. Therefore, in this work, we examined the morphological characters of pollen potentially to be used for the species delimitation of bee flora. A total of 18 bee floral species, classified into 12 different families were collected, pressed, identified and then acetolyized to observe the grains under microscopy. Bee pollen can be described by small, medium to large sized morphotypes presenting five types of shapes, prolate spheroidal in (seven species), sub-prolate (six species), oblate spheroidal (three species), oblate and prolate (one species each) was examined. The observed polar and equatorial diameter were found maximum in Zea mays 73.5 µm and Pelargonium inquinans 66.75 µm respectively. Pollen of six different types was found namely: tricolporate, 3-zonocolporate, monoportae, tetracolporate, tetraporate and mononsulcate. Whereas highest value of colpi length was measured in Grewia tenax (24.55 µm). Exine surface nature of pollen was examined echinate psilate and scabrate. Exine thickness noted to be maximum in Verbena tenuisecta (8.40 µm) and minimum in Citrus macrocarpa (0.4 µm). Bee floral species considered difficult to identify based on other morphological traits were successfully distinguished using pollen quantitative and qualitative traits, confirming the importance of pollen morphology to diagnose characters to correctly identify honeybee flora. RESEARCH HIGHLIGHTS: Pollen diversity among honeybee flora. Highly variations observed via microscopy in pollen micromorphology. Palyno-morph has taxonomic value for the identification of honeybee floral species.

Implication of scanning electron microscopy in the seed morphology with special reference to three subfamilies of Fabaceae.

The current research work was aimed to determine the morphological variation in the seeds of subfamilies Caesalpinioideae, Mimosoideae, and Papilionoideae using scanning electron microscope to investigate the different seed features including; Seed length, width, weight, hilum shape, position, fracture line pattern, pleurogram shape, texture crudeness, ornamentation wall, and surface ornamentation. A total of 12 species were collected. The study reveals that the seed types alters from psilate to rugose, pleurogram shape from lunar to U shape, hilum shape from elliptical to depressed, hilum position from terminal to subterminal, fracture line pattern from reticulate irregular ridges to psilate with regular ridges, texture crudeness from fine to coarse, surface ornamentation from reticulate to psilate, and ornamentation wall also varies from thin to thick. In all the studied species, it was found that seed surface was brown in color except in Senna alata, in which seed surface was black. Regarding the seed size, it was found that the smallest seed was observed for Sesbania sesban, while the largest seed was observed for Pongamia pinnata. The present research article indicates the taxonomic significance of seed morphology in the subfamilies Caesalpinioideae, Mimosaceae, and Papilionoideae.

Microscopic implication and evaluation of herbaceous melliferous plants of southern Khyber Pakhtunkhwa-Pakistan using light and scanning electron microscope.

The aim of the present study is to investigate the pollen morphology of melliferous plant taxa of Southern Khyber Pakhtunkhwa-Pakistan. Using light microscope (LM) and scanning electron microscope (SEM), the palynological study of 18 species of melliferous plants namely Calendula arvensis, Cenchrus pennisetiformis, Citrullus colocynthis, Cucumis melo subsp. agrestis var. agrestis, Cucurbita maxima, Cymbopogon jwarancusa, Cynodon dectylon, Dactyloctenium aegyptium, Helianthus annus, Lagenaria siceraria, Launaea procumbens, Luffa cylindrica, Pennisetum glaucum, Saccharum spontaneum, Sonchus asper, Verbesina encelioides, Xanthium strumarium, and Zea mays was carried out. Both qualitative and quantitative characteristics of pollen were studied. Variations were observed in pollen morphology. The dominant pollen shape was prolate-spheroidal (11 species). All the pollen units were monad. The highest exine thickness was found in Citrullus colocynthis (8.45 µm). The maximum polar and equatorial diameter (102 and 97.55 µm) was found in Luffa cylindrica. Similarly, the highest P/E ratio was found in Cucurbita maxima (1.46). Most of the species showed tricolpate and monoporate type of pollen. The exine sculpturing, number of spines per pollen and between colpi and the pollen fertility and sterility provided significant results for the documentation of melliferous plants. Thus, the information listed in this article will prove helpful to identify the potential melliferous plants in the area, geographical origin of the honey, and the availability of pure honey in the local and international market.

Microscopic investigation of pollen morphology of Brassicaceae from Central Punjab-Pakistan.

The intention of the current study is to provide an account on the palynological features of Brassicaceae from Central Punjab-Pakistan as a basis for future studies. Different morpho-palynological characteristics both qualitative and quantitative were analyzed during this research which includes shape of pollen, diameter of pollen, P/E ratio, exine sculpturing, thickness of exine, type of pollen, shape and size of lumens, and thickness of murus. Taxonomic keys were also constructed based on pollen morphological characters for correct identification of species. This study aims to provide detailed information of pollen diversity and their exine structure based on both qualitative and quantitative characters by using Light microscopy and Scanning electron microscopy. Shape of pollen is mostly prolate, but some species also have sub-prolate to spheroidal prolate types. Exine ornamentation in most species was reticulate, whereas micro reticulate (one species) and coarsely reticulate (one species) exine also observed in some pollen. All the pollen mentioned in this study have tricolpate apertures. Variation found in thickness of exine and other characters proved to be helpful at generic and specific level. The results reinforced the significance of pollen morphological features of family Brassicaceae and aid for valuable taxonomic tool in plant systematics.

3-Hydr-oxy-1,2,3,9-tetra-hydro-pyrrolo[2,1-b]quinazolin-4-ium chloride dihydrate: (+)-vasicinol hydro-chloride dihydrate from Peganum harmala L.

The title compound, C(11)H(13)N(2)O(+)·Cl(-)·2H(2)O, the dihydrate of (+)-vasicinol hydro-chloride, is a pyrrolidinoquinazoline alkaloid. It was isolated from the ethyl acetate fraction of the leaves of Peganum harmala L. The pyrrolidine ring has an envelope conformation with the C atom at position 2 acting as the flap and the C atom at position 3, carrying the hydroxyl substituent, has an S configuration. The absolute configuration was determined as a result of the anomalous scattering of the Cl atom. In the crystal structure, mol-ecules stack along the a axis, connected to one another via inter-molecular O-H⋯Cl and N-H⋯Cl hydrogen bonds, forming approximately triangular-shaped R(2) (1)(7) rings, and O-H⋯Cl and O-H⋯O hydrogen bonds, forming penta-gonal-shaped R(5) (4)(10) rings. The overall effect is a ribbon-like arrangement running parallel to the a axis.