Introduction: Covid-19 and the conditions and struggles of agrarian classes of labour.

Covid-19 generated a crisis in capitalism, but not of capitalism. Capitalism reproduces itself in crisis and in ways that have significant but uneven impacts on the conditions and struggles of agrarian classes of labour. This article explores preliminary studies of how Covid-19 has affected agrarian social formations in Africa, Asia and Latin America and the farmers, petty commodity producers, labourers and agribusinesses who populate them. It considers some of the implications for wage-labour, agriculture, accumulation and social reproduction including care work. And it briefly considers Covid-19's political impacts-in terms of the role of the state and possibilities for challenging capitalism, its violence and its ecological crisis.

Review of synthesis, assay, and prediction of ß and γ-secretase inhibitors.

Alzheimer's disease (AD) is characterize with several pathologies this disease, amyloid plaques, composed of the ß-amyloid peptide and ß-amyloid peptide are hallmark neuropathological lesions in Alzheimer's disease brain. Indeed, a wealth of evidence suggests that ß-amyloid is central to the pathophysiology of AD and is likely to play an early role in this intractable neurodegenerative disorder. AD is the most prevalent form of dementia, and current indications show that twenty-nine million people live with AD worldwide, a figure expected rise exponentially over the coming decades. Clearly, blocking disease progression or, in the best-case scenario, preventing AD altogether would be of benefit in both social and economic terms. However, current AD therapies are merely palliative and only temporarily slow cognitive decline, and treatments that address the underlying pathologic mechanisms of AD are completely lacking. While familial AD (FAD) is caused by autosomal dominant mutations in either amyloid precursor protein (APP) or the presenilin (PS1, PS2) genes. First, we revised Desing, synthesis, and Biological assay of ß and γ-secretase inhibitors. Next, we review 2D QSAR, 3D QSAR, CoMFA, CoMSIA and Docking with different compound to find out the structural requirements. Next, we revised QSAR studies using method of Artificial Neural Network (ANN) in order to understand the essential structural requirement for binding with receptor for ß and γ-secretase inhibitors.

Review of synthesis, biological assay and QSAR studies of ß-secretase inhibitors.

Alzheimer's disease (AD) is highly complex. While several pathologies characterize this disease, amyloid plaques, composed of the ß-amyloid peptide, are hallmark neuropathological lesions in Alzheimer's disease brain. Indeed, a wealth of evidence suggests that ß-amyloid is central to the pathophysiology of AD and is likely to play an early role in this intractable neurodegenerative disorder. The BACE-1 enzyme is essential for the generation of ß-amyloid. BACE-1 knockout mice do not produce ß-amyloid and are free from Alzheimer's associated pathologies, including neuronal loss and certain memory deficits. The fact that BACE-1 initiates the formation of ß-amyloid, and the observation that BACE-1 levels are elevated in this disease provide direct and compelling reasons to develop therapies directed at BACE-1 inhibition, thus reducing ß-amyloid and its associated toxicities. In this sense, quantitative structure-activity relationships (QSAR) could play an important role in studying these ß-secretase inhibitors. QSAR models are necessary in order to guide the ß-secretase synthesis. This work is aimed at reviewing different design and synthesis and computational studies for a very large and heterogeneous series of ß-secretase inhibitors. First, we review design, synthesis, and Biological assay of ß-secretase inhibitors. Next, we review 2D QSAR, 3D QSAR, CoMFA, CoMSIA and Docking with different compounds to find out the structural requirements. Next, we review QSAR studies using the method of Linear Discriminant Analysis (LDA) in order to understand the essential structural requirement for receptor binding for ß- secretase inhibitors.