The gene responsible for Friedreich's ataxia, a disease characterized by neurodegeneration and cardiomyopathy, has recently been cloned and its product designated frataxin. A gene in Saccharomyces cerevisiae was characterized whose predicted protein product has high sequence similarity to the human frataxin protein. The yeast gene (yeast frataxin homolog, YFH1) encodes a mitochondrial protein involved in iron homeostasis and respiratory function. Human frataxin also was shown to be a mitochondrial protein. Characterizing the mechanism by which YFH1 regulates iron homeostasis in yeast may help to define the pathologic process leading to cell damage in Friedreich's ataxia.

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A conflict probe is an air traffic management decision support tool that predicts aircraft-toaircraft and aircraft-to-airspace conflicts. In order to achieve the confidence of the air traffic controllers who are provided this tool, a conflict probe must accurately predict these events. To ensure their continued confidence, the accuracy should not only be assessed in the laboratory before the probe is deployed but continue to be reassessed as the system undergoes upgrades and software changes. Furthermore, it is desirable to use recorded air traffic data to test these tools in order to preserve real-world errors that affect their performance. This paper utilizes a proven approach that modifies surveillance radar track data in time to create traffic scenarios containing conflicts with characteristic properties similar to those encountered in actual air traffic operations. It is these time shifted traffic scenarios that are used to evaluate the conflict probe.evaluating the missed and false conflict predictions, the calculation of the corresponding error probabilities, and a regression testing methodology to examine two runs of the conflict probe to determine if the conflict prediction accuracy has improved or degraded over time. A detailed flight example is presented which illustrates the specific processing involved in conflict accuracy analysis. Next using a scenario of many flights, a methodology utilizing categorical data analysis techniques is applied to determine if a new version of the conflict probe's software significantly improved or degraded in conflict prediction accuracy. This paper describes the detailed process of

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