Conventional theory predicts that ultrahigh lattice thermal conductivity can only occur in crystals composed of strongly bonded light elements, and that it is limited by anharmonic three-phonon processes. We report experimental evidence that departs from these long-held criteria. We measured a local room-temperature thermal conductivity exceeding 1000 watts per meter-kelvin and an average bulk value reaching 900 watts per meter-kelvin in bulk boron arsenide (BAs) crystals, where boron and arsenic are light and heavy elements, respectively. The high values are consistent with a proposal for phonon-band engineering and can only be explained by higher-order phonon processes. These findings yield insight into the physics of heat conduction in solids and show BAs to be the only known semiconductor with ultrahigh thermal conductivity.

The conserved Ipl1 protein kinase is essential for proper chromosome segregation and thus cell viability in the budding yeast Saccharomyces cerevisiae. Its human homologue has been implicated in the tumorigenesis of diverse forms of cancer. We show here that sister chromatids that have separated from each other are not properly segregated to opposite poles of ipl1-2 cells. Failures in chromosome segregation are often associated with abnormal distribution of the spindle pole–associated Nuf2-GFP protein, thus suggesting a link between potential spindle pole defects and chromosome missegregation in ipl1 mutant cells. A small fraction of ipl1-2 cells also appears to be defective in nuclear migration or bipolar spindle formation. Ipl1 associates, probably directly, with the novel and essential Sli15 protein in vivo, and both proteins are localized to the mitotic spindle. Conditional sli15 mutant cells have cytological phenotypes very similar to those of ipl1 cells, and the ipl1-2 mutation exhibits synthetic lethal genetic interaction with sli15 mutations. sli15 mutant phenotype, like ipl1 mutant phenotype, is partially suppressed by perturbations that reduce protein phosphatase 1 function. These genetic and biochemical studies indicate that Sli15 associates with Ipl1 to promote its function in chromosome segregation.

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Background: Cardiac myxomas are rare but are the most common cardiac tumors. This study is based on our clinical experience with cardiac myxomas over a period of 11 years at Sejong General Hospital. We focused on the embolic complications of patients with cardiac myxoma. Methods: We retrospectively reviewed the medical records of 59 consecutive patients with cardiac myxoma who were treated between January 2000 and March 2011. The myxomas were divided into two types: type 1, with an irregular or villous surface and a soft consistency, and type 2, with a smooth surface and a compact consistency. The 59 investigated patients were classified into the embolic group and the non-embolic group. Results: Cardiac obstructive symptoms, embolic events and constitutional symptoms were observed in 37 (62.7%), 13 (22.0%) and 10 (16.9%) patients, respectively. When the embolic and non-embolic groups were compared, there were no significant differences in vascular risk factors, the ejection fraction, the left atrial diameter or the tumor size. However, type 1 myxomas were significantly more frequent in the embolic group (p = 0.009 by Fisher’s exact test). A binary logistic regression analysis showed that type 1 pathology alone was independently associated with myxoma-related embolism (p = 0.008; odds ratio 10.056; 95% confidence interval 1.828–55.337). There were no operative deaths in any of the 59 patients studied. Among the 13 patients with embolism, 11 (84.6%) had brain infarcts. The main patterns of the lesions were multiple lesions (8 out of 11 patients, 72.7%) and lesions in the middle cerebral artery territories (7 out of 11 patients, 63.6%). The other 2 patients were found to have occlusion of the left central retinal artery and left external iliac artery. Additionally, incidental cerebral aneurysms were found in the latter case. There was no recurrence of myxoma or myxoma-related symptoms in the 53 patients receiving outpatient management during the follow-up period (range 2 months to 11 years). Conclusions: The embolic potential of myxoma was associated with an irregular surface pathology but not with vascular risk factors. Echocardiography should be performed in patients with embolic events, especially when cerebral infarcts with multiple territorial lesions are detected. Surgical resection is a relatively safe and curative procedure for cardiac myxoma.