Effect of shell thickness on exciton and biexciton binding energy of a ZnSe/ZnS core/shell quantum dot

The exciton and biexciton binding energy have been studied for a ZnSe/ZnS core/shell quantum dot using WKB (Wentzel-Kramers-Brillouin) approximation. The exciton binding energy increases for small shell thickness and for large thickness, the binding energy again starts decreasing. A similar result is obtained for biexcitons where for thicker shells, the biexciton attains antibonding.Comment: 5 Figure

The impact of the COVID-19 pandemic on the education of medical, dental and non-medical healthcare professionals in Bangladesh : findings and connotation

Lockdown measures in response to the COVID-19 pandemic had an appreciable impact on the education of all medical, dental, and non-medical healthcare professional (HCP) students. These included the closure of universities necessitating a rapid move to e-learning and new approaches to practical’s. However initially, there was a lack of knowledge and expertise regarding e-learning approaches and the affordability of internet bundles and equipment. We initially con-ducted two pilot studies to assess such current challenges, replaced by a two-stage approach including a full investigation involving 32 private and public universities during the early stages of the pandemic followed by a later study assessing the current environment brought about by the forced changes. Top challenges at the start of the pandemic included a lack of familiarity with e-learning approaches, cost of the internet, lack of IT equipment and the quality of the classes. Universities offered support to staff and students to a varying degree to address identified challenges. Since then, e-learning approaches have widened the possibilities for teaching and learning at convenient times. However, challenges remain. In conclusion, there were considerable challenges at the start of them pandemic. Several key issues have been addressed with hybrid learning here to stay. Remaining challenges include a lack of ICT equipment. However, new innovations will continue

THELOHANELLOIDES BENGALENSIS GEN. AND SP. NOV. (MYXOSPOREA : THELOHANELLIDAE) FROM THE GALL BLADDER OF MARINE CAT FISH OF THE BAY OF BENGAL, INDIA

Thelohanelloides bengaknsis gen. nov. sp. nov. (Myxosporea : Thelohancllidac) has been described from the gall bladder ofindian marine cat fish Anus sagor (Hamilton-Buchanan) from the Bay of Bengal coast of West Bengal. India

TWO NEW SPECIES OF COCCIDIA (APICOMPLEX: EIMERIIDAE) FROM ESTURINE FISHES OF WEST BENGAL, INDIA

During the survey of the parasitic protozoa of teleost fish, two new species of Coccidia are observed from two estuarine fish of West Bengal, India. For the features discussed later, the Coccidian species have been considered new to science. The fishes have been collected from the fishermen at Hooghly-Matia estuary and are brought to the laboratory for examination. The parasites when detected, have been kept in a small screwcap tube with 2-3 ml Potassium dichromate solution (2.5%). After 3 days the sporulated oocysts have been Studied under 100X oil immersion lens. The measurements are taken with an occule micrometer (pum) and are based on 30 Oocysts. The line drawings have been made with the aid of Camera lucida. The microphotographs are taken with Meopta kits

FOUR NEW SPECIES OF CERA TOMYXA THELOHAN 1892 (MYXOSPOREA : CERATOMYXIDAE) FROM GALL BLADDER OF SOME TELEOSTS OF THE BAY OF BENGAL COAST OF WEST BENGAL, INDIA

Four new species of Ceratoinyxa Thelohan l892 (Myxosporea : Ceratomyxidae) have been described from the gallbladder of sorne teleosts of the Bay of Bengal. These are Ceratomyxa Jet/ac sp.n. from Anus Jeila, Ceratomyxa militarisa sp.n. from Osteogeneiosus militaris (Linnaeus), Ceratomyxa sit bequalis sp.n. from Anus gagora (Harnilton-Buchanon) of Ariide and C’eratomyxa asymmetrica sp.n. from Liza parsia of Mugilidae

LEAD (Pb) INDUCED ANAEMIA IN SWISS MICE – LIGHT AND SCANNING ELECTRON MICROSCOPIC STUDIES

Marked reductions in blood haemoglobin level, haematocrit value and erythrocyte count were observed after 1 and 2 weeks of intraperitoneal treatment of Swiss mice with lead nitrate (8 mg/Kg for 5 consecutive days per week), as compared to the respective controls. Echinocytic transformation of many erythrocytes and the formation of a few microcytes, as revealed by both light and scanning electron microscopy, indicated the anaemia to be anisocytic and haemolytic in nature. Moreover, leucopenia accompanied by a decrease of lymphocyte count but rise of neutrophil count was apparent after 2 weeks but not 1 week of treatment. However, cytochemical tests (acid-ferrocyanide reaction and crystal violet staining) indicated that lead treatment did not interfere with utilization of iron for haemoglobin synthesis and also, did not cause denaturation of haemoglobin in already formed erythrocytes. The study hints to the necessity of periodic monitoring of blood picture in workers of different lead-based industries