RESUMEN
Task-based runtime systems are an important branch of parallel programming research, since tasks decouple computation from the compute units, giving the runtime systems greater flexibility than a thread-based solution. This makes it easier to deal with the ever-increasing complexity of parallel architectures by providing a separation of concerns-the specification of parallelism is separated from the implementation of the parallel computations on a specific architecture. The Open Community Runtime is one such system, aimed at large-scale parallel systems. Unlike many other task-based runtime systems, the creators not only provided an implementation but there is also a comprehensive specification document. This has allowed us to create an independent implementation, called OCR-Vx. In this article, we present our experience of developing the runtime system, put our work in the context of the specification and the other implementations, and describe key lessons that we have learned during our work. We discuss the design and implementation issues of task-based runtime systems and applications including task synchronization and scheduling, data management, memory consistency, the relation between shared-memory and distributed-memory runtime systems, NUMA architectures, and heterogeneous systems. The article is aimed at audiences not familiar with OCR, since we believe these lessons could be valuable for developers working on other task-based runtime systems or designing new ones.
RESUMEN
BACKGROUND: The objective of the study was to report a rare case of primary neuroendocrine carcinoma of the right kidney in a 36 year old male. METHODS: The patient was clinically assessed; CT and OctreoScan scintigraphy were performed and levels of 5-HIAA, vanillylmandelic acid and NSE were determined. The tumor and metastases were histologically and immunohistochemically examined. RESULTS: The imaging methods showed a cystic tumor in the lower pole of the right kidney. Macroscopically, the entire tumor was sized 8x8x7 cm. Histologically, it was made up of ribbon-line or trabecular patterns of tumor cells. Occasional adenomatoid and cystic structures were present. The tumor cell nuclei were round or oval, with no irregularities and fine lumpy chromatin. The mitotic count was < 1 /10HPF and the proliferation marker Ki-67 was < 1 % of tumor cells. Immunohistochemically, the tumor cells were positive with antibodies against chromogranin A, synaptophysin, CD56 (focally), cytokeratins AE1-AE3 (focally), vimentin (most cells), glucagon (focally), and pancreatic polypeptide (PP; focally). Antibodies against serotonin, somatostatin, gastrin, vasoactive intestinal polypeptide (VIP) and calcitonin did not react with the tumor. The results of biochemical markers (5-HIAA, vanillylmandelic acid and NSE) did not correlate with development or treatment of the tumor. CONCLUSIONS: Primary neuroendocrine carcinoma of the kidney was diagnosed both histologically and immunohistochemically. The patient was clinically investigated using CT and OctreoScan scintigraphy. Within two years from nephrectomy, metastases were found in the right humerus and retrocaval lymph nodes. The metastatic lesions were surgically removed. Currently, the patient's condition is good, with no tumor progression detected.