Comparative analysis of the survival and regeneration potential of juvenile and matured earthworm, Eudrilus eugeniae, upon in vivo and in vitro maintenance.

Eudrilus eugeniae is a clitellum-dependent earthworm that requires intact clitellum segments for its survival and regeneration. The present study aims to interconnect the survival and regeneration ability that varies between in vivo and in vitro maintenance upon different sites of amputation. The amputated portion of the worm that possesses intact clitellum (13th-18th segments) survived and had the potential to regenerate, whereas worms with partial or without clitellum segments only survived and were unable to regenerate. Besides segment length and clitellum segments, clitellum factors also determined the survival, blastemal initiation and differentiation potential. The survivability and regeneration potential of worms were augmented upon in vitro maintenance. Notably, the amputated segments (1st-10th segments) and posterior segments of similar length, which usually die within the 4th day in vivo, survived for more than 60 days in vitro but lacked the regeneration ability. On the other hand, the amputated posterior segments (30th to 37th segments) from juvenile worms, maintained in in vitro condition, survived and initiated blastema with multiple buds but lacked the ability to regenerate. Interestingly, the equal half of adult worm blastema that is maintained in in vitro conditions were able to form the blastema-like structure with the help of a unique stick. The anterior blastema failed to retain the regenerative structure but the posterior portion of the amputated blastema, which is also associated with a small portion of the body segment, showed the ability to retain the regenerative structure. Our results conclude that the survivability is enhanced upon in vitro maintenance and this condition favours the adult dedifferentiated blastemal and stem cell-enriched juvenile posterior segments to form a regenerative blastema.

Current scenario of solid waste management techniques and challenges in Covid-19 - A review.

Annually, world generates 2.01 billion tonnes of solid wastes and it is expected to generate 2.2 billion tonnes of solid waste by 2025. Globally double the amount of waste generation was anticipated by 2050, hence an urgent action is required for this intricate problem in adopting better management techniques and recycling strategies. Unfortunately, poor management of wastes causes vulnerable effects to the society in terms of health. Waste management is the key infrastructure to be developed in society, but so far it is not recognized as much in many developing countries. Significant innovations and improvements are made in the last few decades globally, but still 2 to 3 billion people around the world lack access to waste collection services. The aim of this present study is to give an overview of different types of waste techniques that are effectively followed by different countries and the action plans need to follow. This review focuses on the global current scenario of waste generation, and its management methods with relevant literatures providing the upgrades in the phases of waste management services like collection and transport, various techniques adopted for waste management, policies and legislation, countries investment in waste management process and the impact of solid waste management during Covid-19. Collectively we conclude that Asian countries need to allot more fund for handling solid waste. Also with the available waste management technique, it is not possible to achieve zero waste. Therefore, more new techniques are needed to be adapted.