Cut Tree Construction from Massive Graphs

The construction of cut trees (also known as Gomory-Hu trees) for a given graph enables the minimum-cut size of the original graph to be obtained for any pair of vertices. Cut trees are a powerful back-end for graph management and mining, as they support various procedures related to the minimum cut, maximum flow, and connectivity. However, the crucial drawback with cut trees is the computational cost of their construction. In theory, a cut tree is built by applying a maximum flow algorithm for $n$ times, where $n$ is the number of vertices. Therefore, naive implementations of this approach result in cubic time complexity, which is obviously too slow for today's large-scale graphs. To address this issue, in the present study, we propose a new cut-tree construction algorithm tailored to real-world networks. Using a series of experiments, we demonstrate that the proposed algorithm is several orders of magnitude faster than previous algorithms and it can construct cut trees for billion-scale graphs.Comment: Short version will appear at ICDM'1

Electromagnetically levitated vibration isolation system for the manufacturing process of silicon monocrystals

This paper introduces a study on an Electromagnetically Levitated Vibration Isolation System (ELVIS) for isolation control of large-scale vibration. This system features no mechanical contact between the isolation table and the installation floor, using a total of four electromagnetic actuators which generate magnetic levitation force in the vertical and horizontal directions. The configuration of the magnet for the vertical direction is designed to prevent any generation of restoring vibratory force in the horizontal direction. The isolation system is set so that vibration control effects due to small earthquakes can be regulated to below 5(gal) versus horizontal vibration levels of the installation floor of up t 25(gal), and those in the horizontal relative displacement of up to 30 (mm) between the floor and levitated isolation table. In particular, studies on the relative displacement between the installation floor and the levitated isolation table have been made for vibration control in the horizontal direction. In case of small-scale earthquakes (Taft wave scaled: max. 25 gal), the present system has been confirmed to achieve a vibration isolation to a level below 5 gal. The vibration transmission ratio of below 1/10 has been achieved versus continuous micro-vibration (approx. one gal) in the horizontal direction on the installation floor

Positioning and Microvibration Control by Electromagnets of an Air Spring Vibration Isolation System

Active positioning and microvibration control has been attempted by electromagnets equipped in a bellows-type, air-spring vibration isolation system. Performance tests have been carried out to study the effects. The main components of the system's isolation table were four electromagnetic actuators and controllers. The vibration isolation table was also equipped with six acceleration sensors for detecting microvibration of the table. The electromagnetic actuators were equipped with bellows-type air springs for passive support of the weight of the item placed on the table, with electromagnets for active positioning, as well as for microvibration control, and relative displacement sensors. The controller constituted a relative feedback system for positioning control and an absolute feedback system for vibration isolation control. In the performance test, a 1,490 kg load (net weight of 1,820 kg) was placed on the vibration isolation table, and both the positioning and microvibration control were carried out electromagnetically. Test results revealed that the vibration transmission was reduced by 95%

H3K9 Demethylases JMJD1A and JMJD1B Control Prospermatogonia to Spermatogonia Transition in Mouse Germline

Histone H3 lysine 9 (H3K9) methylation is dynamically regulated by methyltransferases and demethylases. In spermatogenesis, prospermatogonia differentiate into differentiating or undifferentiated spermatogonia after birth. However, the epigenetic regulation of prospermatogonia to spermatogonia transition is largely unknown. We found that perinatal prospermatogonia have extremely low levels of di-methylated H3K9 (H3K9me2) and that H3K9 demethylases, JMJD1A and JMJD1B, catalyze H3K9me2 demethylation in perinatal prospermatogonia. Depletion of JMJD1A and JMJD1B in the embryonic germline resulted in complete loss of male germ cells after puberty, indicating that H3K9me2 demethylation is essential for male germline maintenance. JMJD1A/JMJD1B-depleted germ cells were unable to differentiate into functional spermatogonia. JMJD1 isozymes contributed to activation of several spermatogonial stem cell maintenance genes through H3K9 demethylation during the prospermatogonia to spermatogonia transition, which we propose is key for spermatogonia development. In summary, JMJD1A/JMJD1B-mediated H3K9me2 demethylation promotes prospermatogonia to differentiate into functional spermatogonia by establishing proper gene expression profiles

A novel laser melting sampler for discrete, sub-centimeter depth-resolved analyses of stable water isotopes in ice cores

We developed a novel laser melting sampler (LMS) for ice cores to measure the stable water isotope ratios (δ18O and δD) as temperature proxies at sub-centimeter depth resolutions. In this LMS system, a 2 mm diameter movable evacuation nozzle holds an optical fiber through which a laser beam irradiates the ice core. The movable nozzle intrudes into the ice core, the laser radiation meanwhile melts the ice cylindrically, and the meltwater is pumped away simultaneously through the same nozzle and transferred to a vial for analysis. To avoid isotopic fractionation of the ice through vaporization, the laser power is adjusted to ensure that the temperature of the meltwater is always kept well below its boiling point. A segment of a Dome Fuji shallow ice core (Antarctica), using the LMS, was then demonstrated to have been discretely sampled with a depth resolution as small as 3 mm: subsequent analysis of δ18O, δD, and deuterium excess (d) was consistent with results obtained by hand segmentation within measurement uncertainties. With system software to control sampling resolution, the LMS will enable us to identify temperature variations that may be detectable only at sub-centimeter resolutions in ice cores

Langerhans cell histiocytosis of the sternum

We report a rare case of Langerhans cell histiocytosis involving the sternum. The patient was a 12-year-old girl presenting with anterior chest pain and swelling. Radiographs and computed tomography showed an osteolytic lesion in the sternum. Technetium bone scintigraphy revealed increased uptakes in the sternum, the greater trochanter of the right femur, and the right distal tibia. Incisional biopsy for the sternum lesion was performed, and the histopathologic diagnosis was Langerhans cell histiocytosis. She was treated with chemotherapy and the symptoms disappeared

Molecular Characteristics of Extended-Spectrum Beta-Lactamases and qnr Determinants in Enterobacter Species from Japan

The incidence of extended-spectrum β-lactamases (ESBLs) has been increasing worldwide, but screening criteria for detection of ESBLs are not standardized for AmpC-producing Enterobacteriaceae such as Enterobacter species. In this study, we investigated the prevalence of ESBLs and/or AmpC β-lactamases in Japanese clinical isolates of Enterobacter spp. and the association of plasmid-mediated quinolone resistance (PMQR) determinants with ESBL producers. A total of 364 clinical isolates of Enterobacter spp. collected throughout Japan between November 2009 and January 2010 were studied. ESBL-producing strains were assessed by the CLSI confirmatory test and the boronic acid disk test. PCR and sequencing were performed to detect CTX-M, TEM, and SHV type ESBLs and PMQR determinants. For ESBL-producing Enterobacter spp., pulsed-field gel electrophoresis (PFGE) was performed using XbaI restriction enzyme. Of the 364 isolates, 22 (6.0%) were ESBL producers. Seven isolates of Enterobacter cloacae produced CTX-M-3, followed by two isolates producing SHV-12. Two isolates of Enterobacter aerogenes produced CTX-M-2. Of the 22 ESBL producers, 21 had the AmpC enzyme, and six met the criteria for ESBL production in the boronic acid test. We found a significant association of qnrS with CTX-M-3-producing E. cloacae. The 11 ESBL-producing Enterobacter spp. possessing blaCTX-M, blaSHV, or blaTEM were divided into six unique PFGE types. This is the first report about the prevalence of qnr determinants among ESBL-producing Enterobacter spp. from Japan. Our results suggest that ESBL-producing Enterobacter spp. with qnr determinants are spreading in Japan

Phase II trial of erlotinib in patients with advanced non-small-cell lung cancer harboring epidermal growth factor receptor mutations: additive analysis of pharmacokinetics

Background: We conducted a phase II trial of erlotinib in patients with advanced non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations and evaluated the relationship between plasma concentration and efficacy of erlotinib. Methods: Patients who were previously treated but naive to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs), with advanced NSCLC harboring EGFR mutations, were enrolled. Erlotinib was given at 150 mg once daily until disease progression. The primary end point was objective response rate (ORR). Plasma trough levels of erlotinib were measured on Days 2 (D2) and 8 (D8) by high-performance liquid chromatography. Results: In total, 29 patients were enrolled from September 2008 to January 2011. ORR was 61.5 % (95 % confidence interval [CI] 40.57-79.8) of 26 assessable patients. The median progression-free survival (PFS) and overall survival (OS) were 6.3 months and 16.9 months, respectively. Skin rash was observed in 24 patients, mostly at grade 1 or 2. Grade 2 pneumonitis was observed in one patient. We collected blood samples from 16 patients. The median PFS of the high and low D8/D2 ratio group was 11.2 months and 5.7 months, respectively (p = 0.044, hazard ratio = 0.301, 95 % CI 0.094-0.968). Conclusion: Erlotinib showed an ORR comparable to that seen in previous studies for patients with NSCLC harboring EGFR mutations, although response, the primary end point, did not reach the predetermined threshold level. The D8/D2 ratio of erlotinib plasma trough levels might be a predictive factor for PFS

Genome-Wide Association Study Confirming Association of HLA-DP with Protection against Chronic Hepatitis B and Viral Clearance in Japanese and Korean

Hepatitis B virus (HBV) infection can lead to serious liver diseases, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC); however, about 85–90% of infected individuals become inactive carriers with sustained biochemical remission and very low risk of LC or HCC. To identify host genetic factors contributing to HBV clearance, we conducted genome-wide association studies (GWAS) and replication analysis using samples from HBV carriers and spontaneously HBV-resolved Japanese and Korean individuals. Association analysis in the Japanese and Korean data identified the HLA-DPA1 and HLA-DPB1 genes with Pmeta = 1.89×10−12 for rs3077 and Pmeta = 9.69×10−10 for rs9277542. We also found that the HLA-DPA1 and HLA-DPB1 genes were significantly associated with protective effects against chronic hepatitis B (CHB) in Japanese, Korean and other Asian populations, including Chinese and Thai individuals (Pmeta = 4.40×10−19 for rs3077 and Pmeta = 1.28×10−15 for rs9277542). These results suggest that the associations between the HLA-DP locus and the protective effects against persistent HBV infection and with clearance of HBV were replicated widely in East Asian populations; however, there are no reports of GWAS in Caucasian or African populations. Based on the GWAS in this study, there were no significant SNPs associated with HCC development. To clarify the pathogenesis of CHB and the mechanisms of HBV clearance, further studies are necessary, including functional analyses of the HLA-DP molecule