583 research outputs found
Sharing Computing Resources with Virtual Machines by Transparent Data Access
Cloud computing has rapid growth in enterprise and academic areas. Computing platform makes up the transition from physical servers to virtual machines (VMs) in the cloud. Instead of many advantages, VMs remain several problems to employ effective utilization of physical computing resources, especially many-core accelerators. Even though GPGPU is a hopeful solution for high-load applications, existing methods to utilize GPUs from VMs are subjected to various restraints. In order to solve this problem, we propose a flexible method to share external computing resources by providing transparent access for data in the VMs. By committing commands to a computing host which processes the jobs as substitution, VMs can process high load jobs as necessary even if the VM has a tiny configuration. The computing host mounts the working directories in the VMs and enqueues jobs committed by the VMs. Experimental results show that the overhead of our implementation is sufficiently small in the low I/O load processes
A Light-weight Content Distribution Scheme for Cooperative Caching in Telco-CDNs
A key technique to reduce the rapid growing of video-on-demand’s traffic is a cooperative caching strategy aggregating multiple cache storages. Many internet service providers have considered the use of cache servers on their networks as a solution to reduce the traffic. Existing schemes often periodically calculate a sub-optimal allocation of the content caches in the network. However, such approaches require a large computational overhead that cannot be amortized in a presence of frequent changes of the contents’ popularities. This paper proposes a light-weight scheme for a cooperative caching that obtains a sub-optimal distribution of the contents by focusing on their popularities. This was made possible by adding color tags to both cache servers and contents. In addition, we propose a hybrid caching strategy based on Least Frequently Used (LFU) and Least Recently Used (LRU) schemes, which efficiently manages the contents even with a frequent change in the popularity. Evaluation results showed that our light-weight scheme could considerably reduce the traffic, reaching a sub-optimal result. In addition, the performance gain is obtained with a computation overhead of just a few seconds. The evaluation results also showed that the hybrid caching strategy could follow the rapid variation of the popularity. While a single LFU strategy drops the hit ratio by 13.9%, affected by rapid popularity changes, our proposed hybrid strategy could limit the degradation to only 2.3%
An Appropriate Number of Hidden Units for Three Layered Neural Networks to Parity Discrimination
Effect of Plant Diversity on Ruminal Degradability of Goats Grazing in a Semi-natural Pasture
Poster Session
A New 100-GHz Band Front-End System with a Waveguide-Type Dual-Polarization Sideband-Separating SIS Receiver for the NRO 45-m Radio Telescope
We developed a waveguide-type dual-polarization sideband-separating SIS
receiver system of the 100-GHz band for the 45-m radio telescope at the
Nobeyama Radio Observatory, Japan. This receiver is composed of an ortho-mode
transducer and two sideband-separating SIS mixers, which are both based on the
waveguide technique. The receiver has four intermediate frequency bands of
4.0--8.0 GHz. Over the radio frequency range of 80--120 GHz, the
single-sideband receiver noise temperatures are 50--100 K and the image
rejection ratios are greater than 10 dB. We developed new matching optics for
the telescope beam as well as new IF chains for the four IF signals. The new
receiver system was installed in the telescope, and we successfully observed
the 12CO, 13CO and C18O emission lines simultaneously toward the Sagittarius B2
region to confirm the performance of the receiver system. The SSB noise
temperature of the system, including the atmosphere, became approximately half
of that of the previous receiver system. The Image Rejection Ratios (IRRs) of
the two 2SB mixers were calculated from the 12CO and HCO+ spectra from the W51
giant molecular cloud, resulting in > 20 dB for one polarization and > 12 dB
for the other polarization.Comment: 10 pages, 13 figures, Accepted for publication in PASJ, version with
high resolution figures is available via
http://www.nro.nao.ac.jp/library/report/list.htm
Cache-22: A Highly Deployable End-To-End Encrypted Cache System with Post-Quantum Security
Cache systems are crucial for reducing communication overhead on the Internet. The importance of communication privacy is being increasingly and widely recognized; therefore, we anticipate that nearly all end-to-end communication will be encrypted via secure sockets layer/transport layer security (SSL/TLS) in the near future. Herein we consider a catch-22 situation, wherein the cache server checks whether content has been cached or not, i.e., the cache server needs to observe it, thereby violating end-to-end encryption. We avoid this catch-22 situation by proposing an encrypted cache system which we call Cache-22. To maximize its deployability, we avoid heavy, advanced cryptographic tools, and instead base our Cache-22 system purely on traditional SSL/TLS communication. It employs tags for searching, and its design concept enables the service provider to decide, e.g., via an authentication process, whether or not a particular user should be allowed to access particular content. We provide a prototype implementation of the proposed system using the color-based cooperative cache proposed by Nakajima et al. (IEICE Trans. 2017) under several ciphersuites containing post-quantum key exchanges in addition to ECDHE (Elliptic Curve-based). We consider NIST Post-Quantum Cryptography round 3 finalists and alternate candidates: lattice-based (Kyber, SABER, NTRU), code-based (BIKE), and isogeny-based (SIKE). Compared to direct HTTPS communication between a service provider and a user, employing our Cache-22 system has a merit to drastically reduce communications between a cache server and the service provider (approximately 95%) which is effective in a hierarchical network with a cost disparity
Fatty Acid Accumulation and Resulting PPARα Activation in Fibroblasts due to Trifunctional Protein Deficiency
To examine fatty acid accumulation and its toxic effects in cells, we analyzed skin fibroblasts from six patients with mitochondrial trifunctional protein deficiency, who had abnormalities in the second through fourth reactions in fatty acid β-oxidation system. We found free fatty acid accumulation, enhanced three acyl-CoA dehydrogenases, catalyzing the first reaction in the β-oxidation system and being assumed to have normal activities in these patients, and PPARα activation that was confirmed in the experiments using MK886, a PPARα specific antagonist and fenofibrate, a PPARα specific agonist. These novel findings suggest that the fatty acid accumulation and the resulting PPARα activation are major causes of the increase in the β-oxidation ability as probable compensation for fatty acid metabolism in the patients' fibroblasts, and that enhanced cell proliferation and increased oxidative stress due to the PPARα activation relate to the development of specific clinical features such as hypertrophic cardiomyopathy, slight hepatomegaly, and skeletal myopathy. Additionally, significant suppression of the PPARα activation by means of MK886 treatment is assumed to provide a new method of treating this deficiency
Endobronchial Ultrasound Doppler Image Features Correlate with mRNA Expression of hif1-α and vegf-c in Patients with Non–Small-Cell Lung Cancer
IntroductionWe attempted to assess the correlation between the Doppler mode image patterns during endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration and the expression of angiogenesis-related molecules within lymph nodes in patients with non–small-cell lung cancer.MethodsThirty-eight archived EBUS- transbronchial needle aspiration samples of lymph nodes (27 metastatic and 11 nonmetastatic) in patients with non–small-cell lung cancer with Doppler mode ultrasound image were analyzed. The Doppler mode image of the vasculature of the targeted lymph node was categorized into the following groups: normal blood flow, low blood flow (LBF), and high blood flow (HBF). Vascular index ratio (vascular area/lymph node area) of each metastatic lymph node was calculated. Total RNA and protein was extracted and analyzed for expression of HIF-1α, VEGF-A, and VEGF-C by quantitative RT-PCR and enzyme-linked immunosorbent assay.ResultsWithin the 27 metastatic lymph nodes, eight were categorized into the LBF group and 19 into the HBF group. Vascular index ratio was significantly higher in HBF than LBF (p = 0.0003). mRNA expression of HIF-1α and VEGF-A was significantly higher in metastatic lymph nodes than in benign lymph nodes (p < 0.0001). Compared with LBF and HBF, HIF-1α mRNA expression was significantly higher in LBF (p = 0.01) and VEGF-C mRNA expression was significantly higher in HBF (p = 0.0315). There was no significant difference in protein expression by enzyme-linked immunosorbent assay analysis.ConclusionsThe vascularity of metastatic lymph nodes observed by EBUS correlates with the mRNA expression of HIF-1α and VEGF-C (not VEGF-A). This correlation is a clinical utility that needs to be evaluated further
浸潤および血管新生を通しての人肝細胞癌の進行におけるケラチン19分子の役割
BACKGROUND: Keratin (K) 19-positive hepatocellular carcinoma (HCC) is well known to have a higher malignant potential than K19-negative HCC: However, the molecular mechanisms involved in K19-mediated progression of HCC remain unclear. We attempted to clarify whether K19 directly affects cell survival and invasiveness in association with cellular senescence or epithelial-mesenchymal transition (EMT) in K19-positive HCC. METHODS: K19 expression was analysed in 136 HCC surgical specimens. The relationship of K19 with clinicopathological factors and survival was analysed. Further, the effect of K19 on cell proliferation, invasion, and angiogenesis was examined by silencing K19 in the human HCC cell lines, HepG2, HuH-7, and PLC/PRF/5. Finally, we investigated HCC invasion, proliferation, and angiogenesis using K19-positive HCC specimens. RESULTS: Analysis of HCC surgical specimens revealed that K19-positive HCC exhibited higher invasiveness, metastatic potential, and poorer prognosis. In vitro experiments using the human HCC cell lines revealed that K19 silencing suppressed cell growth by inducting apoptosis or upregulating p16 and p27, resulting in cellular senescence. In addition, transfection with K19 siRNA upregulated E-cadherin gene expression, significantly inhibited the invasive capacity of the cells, downregulated angiogenesis-related molecules such as vasohibin-1 (VASH1) and fibroblast growth factor 1 (FGFR1), and upregulated vasohibin-2 (VASH2). K19-positive HCC specimens exhibited a high MIB-1 labelling index, decreased E-cadherin expression, and high microvessel density around cancer foci. CONCLUSION: K19 directly promotes cancer cell survival, invasion, and angiogenesis, resulting in HCC progression and poor clinical outcome. K19 may therefore be a novel drug target for the treatment of K19-positive HCC.博士(医学)・乙第1399号・平成29年3月15日© The Author(s). 2016 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
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