A preliminary study of microbial function in the soil at Canadian low Arctic

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

Shift-Interleave Coding for DNA-Based Storage: Correction of IDS Errors and Sequence Losses

We propose a novel coding scheme for DNA-based storage systems, called the shift-interleave (SI) coding, designed to correct insertion, deletion, and substitution (IDS) errors, as well as sequence losses. The SI coding scheme employs multiple codewords from two binary low-density parity-check codes. These codewords are processed to form DNA base sequences through shifting, bit-to-base mapping, and interleaving. At the receiver side, an efficient non-iterative detection and decoding scheme is employed to sequentially estimate codewords. The numerical results demonstrate the excellent performance of the SI coding scheme in correcting both IDS errors and sequence losses.Comment: submitted to IEEE conferenc

Physical Mechanism for a Temporal Decrease of the Gutenberg-Richter b-Value Prior to a Large Earthquake

Observations of seismicity prior to large earthquakes show that the slope of a Gutenberg-Richter magnitude-frequency relation, referred to as a b-value, sometimes decreases with time to the mainshock. Yet, underlying physical processes associated with the temporal change of a b-value remain unclear. Here we utilize continuum models of fully dynamic earthquake cycles with fault frictional heterogeneities and aim to simulate the temporal variation of a b-value. We first identify a parameter regime in which the model gives rise to an active and accelerating foreshock behavior prior to the mainshock. We then focus on the spatio-temporal pattern of the simulated foreshocks and analyze their statistics. We find that the b-value of simulated foreshocks decreases with time prior to the mainshock. A marked decrease in the resulting b-value occurs over the duration of less than a few percent of the mainshock recurrence interval, broadly consistent with foreshock behaviors and b-value changes as observed in nature and laboratory, rock-friction experiments. In this model, increased shear stresses on creeping (or velocity-strengthening) fault patches resulting from numerous foreshocks make these creeping patches more susceptible to future coseismic slip, increasing the likelihood of large ruptures and leading to a smaller b-value with time. This mechanism differs from a widely invoked idea that the decrease of a b-value is caused by a rapid increase in shear stress that promotes micro-crack growth, and offers a new interpretation of b-value changes prior to a large earthquake

Diversity of cold-adapted ciliates from glacier snow and cryoconite in Arctic region

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階セミナー室

TRPM2 exacerbates central nervous system inflammation in experimental autoimmune encephalomyelitis by increasing production of CXCL2 chemokines

多発性硬化症の新たな病態増悪機構を解明 --TRPM2を介したケモカイン産生が神経炎症の増悪に至る好中球の浸潤を引き起こす--. 京都大学プレスリリース. 2018-09-13.Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system (CNS) characterized by demyelination and axonal injury. Current therapies that mainly target lymphocytes do not fully meet clinical need due to the risk of severe side effects and lack of efficacy against progressive MS. Evidence suggests that MS is associated with CNS inflammation, although the underlying molecular mechanism is poorly understood. Transient receptor potential melastatin 2 (TRPM2), a Ca²⁺-permeable nonselective cation channel, is expressed at high levels in the brain and by immune cells, including monocyte lineage cells. Here, we show that TRPM2 plays a pathological role in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Knockout or pharmacological inhibition of TRPM2 inhibited progression of EAE, and TRPM2-knockout (TRPM2-KO) mice showed lower activation of Iba1-immunopositive monocyte lineage cells and neutrophil infiltration of the CNS than wild-type (WT) mice. Moreover, CXCL2 production in TRPM2-KO mice was significantly reduced at Day 14 although the severity of EAE was the same as that in WT mice at that time point. In addition, we used bone marrow chimeric mice to show that TRPM2 expressed by CNS-infiltrating macrophages contributes to progression of EAE. Since CXCL2 induces migration of neutrophils, these results indicate that reduced expression of CXCL2 in the CNS suppresses neutrophil infiltration and slows progression of EAE in TRPM2-KO mice. Together, the results suggest that TRPM2 plays an important role in progression of EAE pathology and shed light on its putative role as a therapeutic target for MS. SIGNIFICANCE STATEMENT: Current therapies for multiple sclerosis (MS), which mainly target lymphocytes, carry the risk of severe side effects and lack efficacy against the progressive form of the disease. Here, we found that the transient receptor potential melastatin 2 (TRPM2) channel, abundantly expressed in CNS-infiltrating macrophages, plays a crucial role in development of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. EAE progression was suppressed by knockout or pharmacological inhibition of TRPM2; this was attributed to a reduction in CXCL2 chemokine production by CNS-infiltrating macrophages in TRPM2-knockout mice, resulting in suppression of neutrophil infiltration into the CNS. These results reveal an important role of TRPM2 in the pathogenesis of EAE and shed light on its potential as a therapeutic target

Establishing Principles for a More Sustainable Pension System in Japan, and Identifying Challenges (Japanese)

This paper looks into the intermingling of the self insurance and public assistance principles in Japan's government-sponsored pension system that has been eroding public trust in the system. Using a newly developed pension funding model (the RIETI model), we analyze options for reforms quantitatively by clarifying the respective roles to be played by the financially fair insurance model and public assistance to poor retirees. In particular, we have simulated a pair of reform options: (1) fund the entire Basic Pension by the national treasury as a form of minimum guarantee to all the people in accordance with the assistance principle and Employees' Welfare Pension will be purified as a earning-related financially fair system on top of the Basic Pension, (2) reorganizing the National Pension and Employees' Welfare Pension systems into a new integrated, single-tier pension based on an earnings-related financially fair mechanism, with a supplementary pension for low-income pension recipients paid entirely from the national treasury on the basis of the assistance principle. In the first reform option, if the level of Employees' Welfare Pension contributions set out in the 2004 pension reform were maintained for second-tier contributions, a benefit multiplier of approximately 1.91 times the current rate could be achieved. If benefits were maintained at the levels set in the 2004 reform, the contribution rate for the second-tier pension could be reduced to about 11.93%. In these cases, an additional 7-point hike in the consumption tax would be required to fund Basic Pension benefits at the peak of old-age population. In the second reform option, the additional consumption tax would be relatively low, but the asset size of the earning-related pension system would greatly expand, creating a reserve fund twice as large as that under the current system. We have concluded that the capital market impact of introducing such a system needs to be taken into consideration. Furthermore, our simulations demonstrate that switching to such a system would significantly change the relationship between benefits and contributions. Therefore introduction of the new system would improve the return on contributions for some income groups and diminish it for others.

BioGlue® coronary embolism during open heart surgery

AbstractIn cases of iatrogenic coronary embolism during cardiac surgery or percutaneous coronary intervention, small air bubbles or foreign bodies are directly injected, which usually result in serious adverse events if not treated promptly. We herein describe the case of a patient who developed acute myocardial infarction resulting in shock due to BioGlue® (CryoLife, Atlanta, GA, USA)-induced coronary embolism during the surgical repair of aortic dissection and was treated for retrieval of the material using a thrombectomy catheter.<Learning objective: Coronary embolism caused by surgical adhesives is a rare but potentially life-threatening complication. It is important for surgeons to promptly recognize and treat this serious condition in consultation with cardiologists.

Diversity of phototrophic bacteria in Russell Glacier, Greenland

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