Scalable Speech Coding for IP Networks

The emergence of Voice over Internet Protocol (VoIP) has posed new challenges to the development of speech codecs. The key issue of transporting real-time voice packet over IP networks is the lack of guarantee for reasonable speech quality due to packet delay or loss. Most of the widely used narrowband codecs depend on the Code Excited Linear Prediction (CELP) coding technique. The CELP technique utilizes the long-term prediction across the frame boundaries and therefore causes error propagation in the case of packet loss and need to transmit redundant information in order to mitigate the problem. The internet Low Bit-rate Codec (iLBC) employs the frame-independent coding and therefore inherently possesses high robustness to packet loss. However, the original iLBC lacks in some of the key features of speech codecs for IP networks: Rate flexibility, Scalability, and Wideband support. This dissertation presents novel scalable narrowband and wideband speech codecs for IP networks using the frame independent coding scheme based on the iLBC. The rate flexibility is added to the iLBC by employing the discrete cosine transform (DCT) and iii the scalable algebraic vector quantization (AVQ) and by allocating different number of bits to the AVQ. The bit-rate scalability is obtained by adding the enhancement layer to the core layer of the multi-rate iLBC. The enhancement layer encodes the weighted iLBC coding error in the modified DCT (MDCT) domain. The proposed wideband codec employs the bandwidth extension technique to extend the capabilities of existing narrowband codecs to provide wideband coding functionality. The wavelet transform is also used to further enhance the performance of the proposed codec. The performance evaluation results show that the proposed codec provides high robustness to packet loss and achieves equivalent or higher speech quality than state-of-the-art codecs under the clean channel condition

Carbon and oxygen isotopic paleoceanography of the Indian and South Atlantic Oceans: Paleoclimate and paleo-ocean circulation

Ocean circulation is intimately associated with continental arrangement and global climate. The purposes of this study are to reconstruct the water mass structure and the deep ocean circulation in the Indian and South Atlantic Oceans during the Cenozoic. Oxygen and carbon isotopes were studied in Cenozoic sediments at six sites (Sites 752, 754, 756, 757, 758, and 762) in ODP (Ocean Drilling Program) Legs 121 and 122 in the northeastern Indian Ocean. These isotopic records are related to global events occurring in middle Miocene, the Eocene / Oligocene boundary, middle to late Eocene, and the Paleocene / Eocene boundary. To compile those records along with a number of published isotopic data from the Indian and South Atlantic Oceans, adjustments to isotopic ratios have been calculated for different foraminiferal species, and benthic and planktonic foraminiferal isotopic data converted into δ values of dissolved inorganic carbon (DIC) of marine water. The general trends of oxygen and carbon isotopic values show an increase to the south. Averaged values in one million year intervals of oxygen and carbon isotopes were calculated for each ODP and DSDP (Deep Sea Drilling Project) site, and the time and spatial distributions of the oxygen and carbon isotopic values were examined from the estimated paleodepth. In the Paleocene ocean, the vertical distribution of isotopic ratios is uniform. However, notable negative shift in oxygen isotopic the remarkable in the Miocene are recognized at about 1500m paleodepth in the northeastern Indian Ocean. The source of the water masses are assumed to be as follows: AABW (Antarctic Bottom Water) or proto-AABW formed in the Southern Ocean (Atlantic sector) throughout the Cenozoic. In the Paleocene, another water mass may have formed at low latitudes including the Tethyan Sea, and this water may could have been warm and highly saline, judging from oxygen isotopic ratios. This water mass corresponds to WSDW (Warm Saline Deep Water), which have encounterd Proto-AABW at mid latitudes during the early Paleogene. This water mass rapidly reduced in size with the closing of the Tethyan Sea at the Paleocene / Eocene boundary, but still continued to 50 Ma in the Indian Ocean and to 40 Ma in the South Atlantic Ocean. AAIW (Antarctic Intermediate Water) developed from the Oligocene (30 Ma) in the Indian Ocean. Proto-NADW (Proto-North Atlantic Deep Water) distinctly developed from the late Pliocene (3 Ma)

Faunal changes of Oligocene benthic foraminifera in the Eastern Equatorial Pacific sites of ODP Leg 199

Abstrac

Distribution of aquatic mosses in the Soya Coast region, East Antarctica

The distribution of aquatic mosses among 73 lakes in the Soya Coast region, East Antarctica, was surveyed. Two species of mosses, Bryum pseudotriquetrum and Leptobryum sp. were found at the bottom of lakes. B. pseudotriquetrum was found in 38 lakes (52.1%), mainly in freshwater lakes throughout the study area. Leptobryum sp. was found in 26 lakes (35.6%) in a rather restricted area, and mainly in relatively saline lakes

Paleoenvironmental changes of late Holocene in the fresh-water lake of the Skarvsnes region in the Soya Coast, East Antarctica

第3回極域科学シンポジウム　横断セッション「海・陸・氷床から探る後期新生代の南極寒冷圏環境変動」11月26日（月）、27日（火） ２階ラウン

Comparison of water quality feature with Antarctic Lake and Lagoon in Hokkaido

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日（金） 統計数理研究所 3階リフレッシュフロ

Geochemical feature of the sediment core from Lake Skallen Oike in East Antarctica.

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日（金） 統計数理研究所 3階リフレッシュフロ

Z-360, a novel therapeutic agent for pancreatic cancer, prevents up-regulation of ephrin B1 gene expression and phosphorylation of NR2B via suppression of interleukin-1 β production in a cancer-induced pain model in mice

<p>Abstract</p> <p>Background</p> <p>Z-360 is an orally active cholecystokinin-2 (CCK2)/gastrin receptor antagonist currently under development as a therapeutic drug for pancreatic cancer. It was previously reported that Z-360 treatment in combination with gemcitabine prolonged the survival period in a lethal pancreatic cancer xenograft model in mice. In a phase Ib/IIa clinical study, Z-360 treatment displayed a trend of reduced pain in patients with advanced pancreatic cancer in combination with gemcitabine including analgesics such as opioids. Here, we investigated the mechanism of analgesic action of Z-360 in a severe cancer-induced pain model in mice, which is considered to be opioid-resistant, by examining ephrin B1 gene expression, <it>N</it>-methyl-D-aspartate receptor NR2B subunit phosphorylation, and interleukin-1β (IL-1β) production.</p> <p>Results</p> <p>In a mouse model of cancer-induced pain, ephrin B1 gene expression in dorsal root ganglia (DRGs) and the phosphorylation of NR2B in the spinal cord were induced. Z-360 treatment inhibited both ephrin B1 gene expression and the phosphorylation of NR2B. In addition, IL-1β production increased in the cancer-inoculated hind paw of mice, but could be suppressed by treatment with Z-360. Moreover, we observed that the CCK1 receptor antagonist devazepide similarly suppressed up-regulation of ephrin B1 gene expression and IL-1β production, and that the intraperitoneal injection of sulfated CCK-8 induced the production of IL-1β in the cancer-inoculated region.</p> <p>Conclusions</p> <p>We have identified a novel pain cascade, in which IL-1β production in cancer-inoculated regions induces ephrin B1 gene expression in DRGs and then ephrin B1 enhances the tyrosine phosphorylation of NR2B via Eph B receptor in the spinal cord. Notably, Z-360 relieves cancer-induced pain by preventing this pain cascade through the suppression of IL-1β production, likely via the blockade of CCK1 receptor. The pre-clinical results presented here support the analgesic action of Z-360 in pancreatic cancer patients with severe, opioid-resistant pain. Pre-clinical and clinical results have demonstrated that Z-360 combined with gemcitabine represents a promising pancreatic cancer therapy approach with characteristic analgesic effects in addition to the prolongation of survival.</p

Magnetic properties of surficial sediments in Lake Ogawara on the Pacific coast of northeastern Japan: spatial variability and correlation with brackish water stratification

To examine limnological conditions in Lake Ogawara on the Pacific coast of northwestern Japan, we investigated the magnetic properties of dredged bottom sediment originally collected from the lake in the summer of 2011. We used non-destructive methods to measure the low-field magnetic susceptibility shortl after sampling, and anhysteretic remanent magnetization (ARM) was assessed in 2012 and 2015. The ARM acquisition and demagnetization curves from littoral sites showed several patterns that reflect the provenance of the sediments. At water depths below 10 m, the magnetic susceptibility and ARM of greenish black mud with high organic content decreased considerably with the increase in water depth, but ARM increased slightly at water depths greater than 16 m. We also found that the magnetic concentrations of mud samples were reduced markedly during a period of storage for about 3 years. We attributed these reductions to diagenetic loss of magnetic minerals, which had been enhanced at deeper sites. It is possible that the ARM carriers in deeper areas were derived from authigenic formation of iron sulfide or from deposition of suspended matter in the hypolimnion water. We propose that the magnetic properties of surficial sediments are controlled by limnological stratification of the brackish lake water, thus possibly providing an analog for down-core variations of magnetic parameters associated with the modification of magnetic minerals during reductive diagenesis