Berberine for prevention of dementia associated with diabetes and its comorbidities: A systematic review

Background A growing number of epidemiological studies indicate that metabolic syndrome (MetS) and its associated features play a key role in the development of certain degenerative brain disorders, including Alzheimer’s disease and vascular dementia. Produced by several different medicinal plants, berberine is a bioactive alkaloid with a wide range of pharmacological effects, including antidiabetic effects. However, it is not clear whether berberine could prevent the development of dementia in association with diabetes. Objective To give an overview of the therapeutic potential of berberine as a treatment for dementia associated with diabetes. Search strategy Database searches A and B were conducted using PubMed and ScienceDirect. In search A, studies on berberine’s antidementia activities were identified using “berberine” and “dementia” as search terms. In search B, recent studies on berberine’s effects on diabetes were surveyed using “berberine” and “diabetes” as search terms. Inclusion criteria Clinical and preclinical studies that investigated berberine’s effects associated with MetS and cognitive dysfunction were included. Data extraction and analysis Data from studies were extracted by one author, and checked by a second; quality assessments were performed independently by two authors. Results In search A, 61 articles were identified, and 22 original research articles were selected. In search B, 458 articles were identified, of which 101 were deemed relevant and selected. Three duplicates were removed, and a total of 120 articles were reviewed for this study. The results demonstrate that berberine exerts beneficial effects directly in the brain: enhancing cholinergic neurotransmission, improving cerebral blood flow, protecting neurons from inflammation, limiting hyperphosphorylation of tau and facilitating β-amyloid peptide clearance. In addition, evidence is growing that berberine is effective against diabetes and associated disorders, such as atherosclerosis, cardiomyopathy, hypertension, hepatic steatosis, diabetic nephropathy, gut dysbiosis, retinopathy and neuropathy, suggesting indirect benefits for the prevention of dementia. Conclusion Berberine could impede the development of dementia via multiple mechanisms: preventing brain damages and enhancing cognition directly in the brain, and indirectly through alleviating risk factors such as metabolic dysfunction, and cardiovascular, kidney and liver diseases. This study provided evidence to support the value of berberine in the prevention of dementia associated with MetS

How is teacher evaluation policy enacted?-The workings of performativity and micro-politics in Japanese schools

This thesis is concerned with the extent to which new teacher evaluation policies and practices in Japan are about controlling teachers or represent opportunities for authentic professional development. It seeks to examine how the new teacher evaluation policies are embedded within the wider policy formation, what perspectives teachers have on the new policies and what their experiences are, and how the new teacher evaluation policies are actually being enacted in schools. The thesis uses a range of methods to explore these concerns. For the purpose of macro analysis of the new teacher evaluation policies, it examines both primary and secondary documentation around policy development. For studying the impact of the policy in schools, it draws on data from a national survey and in-depth interviews with a sample of teachers and head teachers. In this way, it employs a mixed methods approach in which quantitative data is used to provide a general picture of how teachers experience and perceive the new teacher evaluation policies and practices and qualitative data is used to provide the depth of analysis required to look at the nature of performativity in schools. The concept of performativity has been central to the overall investigation. The study argues for a particular reading of performativity — a work through, as opposed to work upon, perspective. This analytical lens illustrates how the new teacher evaluation policies have played a role in producing or reinforcing the mutually policing relations that lead to destabilisation of teacher’s identities. This thesis concludes that the enactment of new teacher evaluation policies has had significant indirect impacts on teachers and teachers’ work by affecting modes of school management and teachers’ relationships. By illustrating the usefulness of the work through perspective of performativity, it has enabled theorizing of performativity to advance. It also illuminates both congruence and variance between teacher evaluation policies as enacted in Japan and other countries. Japan’s teacher evaluation is no less effective as a measure of political control than its counterparts in other countries, but it can work in a more subtle way: teacher evaluation affects, repositions, and reconstructs teachers’ work and identities through affected relationships as mentioned above. This implies that teachers as well as policymakers should develop a more broad, macro-political and critical perspective on teacher evaluation

Induced Riemannian structures on null hypersurfaces

Given a null hypersurface $L$ of a Lorentzian manifold, we construct a Riemannian metric $\widetilde{g}$ on it from a fixed transverse vector field $\zeta$. We study the relationship between the ambient Lorentzian manifold, the Riemannian manifold $(L,\widetilde{g})$ and the vector field $\zeta$. As an application, we prove some new results on null hypersurfaces, as well as known ones, using Riemannian techniques.Comment: 26 page