Standardless PIXE analysis of thick biomineral structures

The particle-induced X-ray emission (PIXE) of thick biomineral targets provides pertinent surface analysis, but if good reference materials are missing then complementary approaches are required to handle the matrix effects. This is illustrated by our results from qualitative and semiquantitative analysis of biomaterials and calcified tissues in which PIXE usually detected up to 20 elements with Z > 14 per sample, many at trace levels. Relative concentrations allow the classification of dental composites according to the mean Z and by multivariate statistics. In femur bones from streptozotocin-induced diabetic rats, trace element changes showed high individual variability but correlated to each other, and multivariate statistics improved discrimination of abnormal pathology. Changes on the in vitro demineralization of dental enamel suggested that a dissolution of Ca compounds in the outermost layer results in the uncovering of deeper layers containing higher trace element levels. Thus, in spite of significant limitations, standardless PIXE analysis of thick biomineral samples together with proper additional procedures can provide relevant information in biomedical research

Human risk in agriculture: problems and perspectives

Eurasian Studies in Business and Economics book series (EBES, volume 13/1) Series Print ISSN 2364-5067, Series Online ISSN 2364-5075Agriculture is an economic sector facing large risk, mainly from natural factors and despite of relatively low price responsiveness to supply and demand causes output volatility in general. It is a risky business, and risk assessment and management tools have become increasingly important in recent years. Risk assessment and management is a complex process, since the risk arises from different sources. Typically, literature analyzes financial, business, credit, or currency risk. There is lack of research of human risk, especially in agriculture sector. It is important to identify knowledge, attitudes, behaviors, and priorities among farmers regarding safety, health, and risk management. This research focuses on identifying main human risk factors, identifying vulnerable populations in agriculture, including immigrants, migrants, refugees, young and older persons, women, persons with disabilities, and minority workers. The research explores human risk assessment and management problems in agriculture. Only then is it possible to increase safety and health for agriculture workers and decrease human risk manifestation in agriculture and to make the agriculture sector socially beneficial for its nationBioekonomikos plėtros fakultetasVytauto Didžiojo universiteta