GPU Based Software Correlators - Perspectives for VLBI2010

Caused by historical separation and driven by the requirements of the PC gaming industry, Graphics Processing Units (GPUs) have evolved to massive parallel processing systems which entered the area of non-graphic related applications. Although a single processing core on the GPU is much slower and provides less functionality than its counterpart on the CPU, the huge number of these small processing entities outperforms the classical processors when the application can be parallelized. Thus, in recent years various radio astronomical projects have started to make use of this technology either to realize the correlator on this platform or to establish the post-processing pipeline with GPUs. Therefore, the feasibility of GPUs as a choice for a VLBI correlator is being investigated, including pros and cons of this technology. Additionally, a GPU based software correlator will be reviewed with respect to energy consumption/GFlop/sec and cost/GFlop/sec

Pair Plasma Dominance in the Parsec-Scale Relativistic Jet of 3C345

We investigate whether a pc-scale jet of 3C345 is dominated by a normal plasma or an electron-positron plasma. We present a general condition that a jet component becomes optically thick for synchrotron self-absorption, by extending the method originally developed by Reynolds et al. The general condition gives a lower limit of the electron number density, with the aid of the surface brightness condition, which enables us to compute the magnetic field density. Comparing the lower limit with another independent constraint for the electron density that is deduced from the kinetic luminosity, we can distinguish the matter content. We apply the procedure to the five components of 3C345 (C2, C3, C4, C5, and C7) of which angular diameters and radio fluxes at the peak frequencies were obtainable from literature. Evaluating the representative values of Doppler beaming factors by their equipartition values, we find that all the five components are likely dominated by an electron-positron plasma. The conclusion does not depend on the lower cutoff energy of the power-law distribution of radiating particles.Comment: 17 page

Antitumor activity of platinum analogs against human lung cancer cell lines and tumor specimens.

Antitumor activities of five platinum analogs, including cisplatin, carboplatin, 254-S, DWA2114R, and NK121, were compared using five human lung cancer cell lines and 19 tumor specimens obtained from lung cancer patients. The antitumor activity was evaluated by determining the ratio of the maximum tolerated dose of each drug to the 70% tumor growth inhibitory concentration in a colony assay. Cisplatin was the most potent agent, followed by 254-S and carboplatin. DWA2114R and NK121 were less potent than cisplatin and 254-S. Cross-resistance to adriamycin was also investigated using an adriamycin-resistant small cell lung cancer subline, SBC -3/ADM30. SBC-3/ADM30 was 1.7- to 4.0-fold more resistant to cisplatin, carboplatin, NK121, and DWA2114R, than was the parent line, SBC-3, and the subline was 2.0-fold more sensitive to 254-S. Using SBC-3, in vitro combination effects of etoposide and cisplatin, carboplatin, or 254-S were evaluated by the median-effect principle. Synergism was noted when cisplatin and etoposide were combined at a fixed molar ratio of 1:1. Combination of carboplatin and etoposide showed an additive effect. The combination of 254-S and etoposide was antagonistic at low concentrations, but was markedly synergistic at higher concentrations. These data suggested the efficacy of 254-S in the treatment of lung cancer.</p

Efficacy and safety of micafungin in empiric and D-index-guided early antifungal therapy for febrile neutropenia ; A subgroup analysis of the CEDMIC trial

Objectives: The D-index is defined as the area over the neutrophil curve during neutropenia. The CEDMIC trial confirmed the noninferiority of D-index-guided early antifungal therapy (DET) using micafungin to empirical antifungal therapy (EAT). In this study, we evaluated the efficacy and safety of micafungin in these settings. Methods: From the CEDMIC trial, we extracted 67 and 113 patients who received micafungin in the DET and EAT groups, respectively. Treatment success was defined as the fulfilment of all components of a five-part composite end point. Fever resolution was evaluated at seven days after the completion of therapy. Results: The proportion of high-risk treatments including induction chemotherapy for acute leukemia and allogeneic hematopoietic stem cell transplantation was significantly higher in the DET group than in the EAT group (82.1% vs. 52.2%). The efficacy of micafungin was 68.7% (95%CI: 56.2–79.4) and 79.6% (71.0–86.6) in the DET and EAT groups, respectively. When we focused on high-risk treatments, the efficacy was 69.1% (55.2–80.9%) and 78.0% (65.3–87.7%), respectively (P = 0.30). There was no significant difference in any of the 5 components between the two groups. Conclusions: The efficacy of micafungin in patients undergoing high-risk treatment was not strongly impaired in DET compared to that in EAT

Phase II study of ifosfamide, cisplatin, and vindesine combination in advanced non-small cell lung cancer.

Twenty-seven previously untreated patients with unresectable non-small cell lung cancer were treated with a 3-drug combination of ifosfamide, cisplatin, and vindesine as a phase II study. Patients received ifosfamide, 1.3g/m2, on days 1 to 5; cisplatin, 20mg/m2, on days 1 to 5; and vindesine, 3mg/m2, on days 1 and 8; with a sufficient parenteral hydration. Courses were repeated every 4 weeks. Twenty males and seven females with a median age of 61 years were treated and fully evaluated. Five patients had stage IIIA, seven had stage IIIB, and 15 had stage IV disease. One patient with adenocarcinoma achieved a complete response and 16 achieved a partial response, for an overall response rate of 63% (95% confidence limit: 45% to 81%). The median duration of response was 34 weeks (range: 9 to 52 weeks). The median survival time was 58 weeks for patients with IIIA/B disease, and 33 weeks for those with IV disease. The major toxicity was myelosuppression, however, it was generally well-tolerated. These results indicate that the 3-drug combination is active against non-small cell lung cancer and warrants further clinical trials.</p

Mortality and morbidity in two-year disease-free survivors of small cell lung cancer after treatment with combination chemotherapy with or without irradiation.

We evaluated the long-term outcome of 148 patients with small cell lung cancer (SCLC) who had been entered into clinical trials of chemotherapy with or without thoracic and prophylactic cranial irradiation (PCI) between 1981 and 1987. Eighteen patients (12%) survived for 2 or more years. With a minimum follow-up of 4.5 years, 10 of the 18 patients who remained disease-free at 2 years are currently alive and free of SCLC. Seven of these 10 patients currently function as they did before diagnosis. However, three suffer from central nervous system changes of varying degrees in severity which appeared 2-3 years after PCI. Eight of the 18 patients who were disease-free at 2 years have died. Two died of isolated relapse in the brain at 3.6 and 4.2 years after initiation of chemotherapy. Five died of other malignancies while continuing their complete response to SCLC; two of non-small cell lung cancer, two of acute myelogenous leukemia, and one of hepatocellular carcinoma. Another patient died of an unrelated disease without any evidence of SCLC. A small but substantial proportion of patients who underwent intensive treatment will achieve long-term survival; however, these patients remain at higher risk for second cancers and late toxicities. Therefore, attention must be directed to defining the safest way to employ such treatment in the management of SCLC.</p