Experimental observation of Bethe strings

Almost a century ago, string states-complex bound states of magnetic excitations-were predicted to exist in one-dimensional quantum magnets(1). However, despite many theoretical studies(2-11), the experimental realization and identification of string states in a condensed-matter system have yet to be achieved. Here we use high-resolution terahertz spectroscopy to resolve string states in the antiferromagnetic Heisenberg-Ising chain SrCo2V2O8 in strong longitudinal magnetic fields. In the field-induced quantum-critical regime, we identify strings and fractional magnetic excitations that are accurately described by the Bethe ansatz(1,3,4). Close to quantum criticality, the string excitations govern the quantum spin dynamics, whereas the fractional excitations, which are dominant at low energies, reflect the antiferromagnetic quantum fluctuations. Today, Bethe's result(1) is important not only in the field of quantum magnetism but also more broadly, including in the study of cold atoms and in string theory; hence, we anticipate that our work will shed light on the study of complex many-body systems in general

Aquaculture and Fisheries in the Sundarbans and Adjacent Areas in Bangladesh: Resources, Productivity, Challenges and Opportunities

Estuarine aquatic systems and braided rivers in and adjacent to the Sundarbans and the vast area of the Ganges tidal floodplain next to the core forest area in Bangladesh holds rice aquatic faunal diversity and provides plenty of opportunities to grow fish, shrimps and crabs. Currently these systems provide direct employment opportunity for 1.2 million people and indirect or seasonal livelihood for more than 10 million people across the southwest coast. Hilsa is the largest fishery in this region and shrimp brings the highest cash and export earnings. Proper implementation of fisheries regulation is critical to ensure conservation of the rich fish diversity of this region as well as to continue to support livelihood of millions of people living on fisheries. While aquaculture is the major contributor to national fish production, agricultural GDP and export earning, it requires planned advancement from the current state to continue to grow in harmony with environment. Integration with rice and other crops, and with mangrove wherever possible can bring long-term sustainability of these systems. Change in the river flow due to siltation and reduced upstream flow, climate change, sea level rise, outbreak of disease in fish and crustaceans are major challenges for future growth and sustainability of both aquaculture and fisheries in this region. Collaborative and multi-disciplinary research should be undertaken to address these challenges. In addition, there should be mechanism to bring research outputs into use and make impact on sustainability

Guide on Diabetes and COVID-19 for Healthcare Professionals in Bangladesh

The world is suffering from a pandemic of coronavirus disease-2019 (COVID-19), and people with diabetes mellitus (DM) are more vulnerable to the serious effects of the COVID-19. This interaction is alarming, considering the high transmission rate of COVID-19 and the global prevalence of DM. Considering the importance of the link between COVID-19 and DM, Bangladesh Diabetic Association has formed a panel of national and international experts in the field of public health, diabetes, and endocrinology to provide some evidence-based guidance for the prevention and care of people with DM during the COVID-19 pandemic

Guide on Diabetes and COVID-19 for Healthcare Professionals in Bangladesh

The world is suffering from a pandemic of coronavirus disease-2019 (COVID-19), and people with diabetes mellitus (DM) are more vulnerable to the serious effects of the COVID-19. This interaction is alarming, considering the high transmission rate of COVID-19 and the global prevalence of DM. Considering the importance of the link between COVID-19 and DM, Bangladesh Diabetic Association has formed a panel of national and international experts in the field of public health, diabetes, and endocrinology to provide some evidence-based guidance for the prevention and care of people with DM during the COVID-19 pandemic