Purpose: Despite the public health successes of newborn bloodspot screening, uncertainty associated with variant forms of primary screening targets has led to discrepancies in medical management. This study explored health-care providers' approaches to managing atypical forms of inherited metabolic diseases (IMDs) in the absence of evidence-based guidelines.Methods: Semistructured telephone interviews were conducted with metabolic specialists. 3-Methylcrotonyl CoA deficiency and variant forms of phenylketonuria, biotinidase deficiency, and fatty acid oxidation disorders were considered. Data were analyzed inductively and deductively using a novel taxonomy of uncertainty.Results: Health-care providers (n = 12) navigate diagnostic, prognostic, and therapeutic challenges of uncertainty while interpreting patient and family attitudes, preferences, and ideas in the care of children with these result types. Participants explained the limits of classifying mild and atypical metabolic phenotypes.Participants also described the challenge of finding balance between cautious care and overmedicalization. Developing consistent care plans and honest communication with families were perceived as effective strategies when navigating uncertainty.Conclusion: Providers' experiences suggest a need for transparent and accessible guidelines that account for challenges associated with uncertainty generated by screening. Timely consideration of this challenge is warranted with increasing emergence of genotype-first approaches to screening.Genetics in Medicine (2020) 22:566-573; https://doi.

Analytical models for estimating semiconductor losses are commonly used for heatsink selection in the design process of power converters. While such models are established and widely known for different dc-dc converters, rectifiers and inverters, they have not been developed for matrix converters. Therefore, one has to resort to the use of numerical simulation for this purpose. Although numerical simulation is a straightforward approach as long as the power switching devices are properly modeled, it is typically time consuming and requires accurate physical models for the device. In this paper, an analytical approach to characterizing the semiconductor losses of the conventional matrix converter (CMC) and the indirect matrix converter (IMC) is presented. The analytical results are verified against the simulation results from a detailed numerical model under a wide variety of operating conditions.

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