145 research outputs found
Understanding the mechanism of warming amplification in the Arctic: Contributions of the global modeling studies to the GRENE Arctic climate change research project
第6回極域科学シンポジウム特別セッション:[S] 北極温暖化とその影響 ―GRENE 北極気候変動プロジェクトと新しい方向性―11月18日(水) 国立極地研究所 2階 大会議
Centromere/kinetochore is assembled through CENP-C oligomerization
Kinetochore is an essential protein complex required for accurate chromosome segregation. The constitutive centromere-associated network (CCAN), a subcomplex of the kinetochore, associates with centromeric chromatin and provides a platform for the kinetochore assembly. The CCAN protein CENP-C is thought to be a central hub for the centromere/kinetochore organization. However, the role of CENP-C in CCAN assembly needs to be elucidated. Here, we demonstrate that both the CCAN-binding domain and the C-terminal region that includes the Cupin domain of CENP-C are necessary and sufficient for chicken CENP-C function. Structural and biochemical analyses reveal self-oligomerization of the Cupin domains of chicken and human CENP-C. We find that the CENP-C Cupin domain oligomerization is vital for CENP-C function, centromeric localization of CCAN, and centromeric chromatin organization. These results suggest that CENP-C facilitates the centromere/kinetochore assembly through its oligomerization.Hara M., Ariyoshi M., Sano T., et al. Centromere/kinetochore is assembled through CENP-C oligomerization. Molecular Cell 83, 2188 (2023); https://doi.org/10.1016/j.molcel.2023.05.023
Large-scale variations of the energy-water balance on land at high latitudes - Analysis using a wetness index -
第3回極域科学シンポジウム/特別セッション「これからの北極研究」11月28日(水) 国立極地研究所 2階大会議
A statistical study of convective and dynamic instabilities in the polar upper mesosphere above Tromsø
We have studied the convective (or static) and dynamic instabilities between 80 and 100 km above Tromsø (69.6° N,
19.2° E) using temperature and wind data of 6 min and 1 km resolutions primarily almost over a solar cycle obtained
with the sodium lidar at Tromsø. First, we have calculated Brunt–Väisälä frequency (N) for 339 nights obtained from
October 2010 to December 2019, and the Richardson number (Ri) for 210 nights obtained between October 2012 to
December 2019. Second, using those values (N and Ri), we have calculated probabilities of the convective instability
(N2<0) and the dynamic instability (0≤Ri<0.25) that can be used for proxies for evaluating the atmospheric stability. The probability of the convective instability varies from about 1% to 24% with a mean value of 9%, and that of
the dynamic instability varies from 4 to 20% with a mean value of 10%. Third, we have compared these probabilities
with the F10.7 index and local K-index. The probability of the convective instability shows a dependence (its correlation coefcient of 0.45) of the geomagnetic activity (local K-index) between 94 and 100 km, suggesting an auroral
infuence on the atmospheric stability. The probability of the dynamic instability shows a solar cycle dependence (its
correlation coefcient being 0.54). The probability of the dynamic instability shows the dependence of the 12 h wave
amplitude (meridional and zonal wind components) (C.C.=0.52). The averaged potential energy of gravity waves
shows decrease with height between 81 and 89 km, suggesting that dissipation of gravity waves plays an important
role (at least partly) in causing the convective instability below 89 km. The probability of the convective instability
at Tromsø appears to be higher than that at middle/low latitudes, while the probability of the dynamic instability is
similar to that at middle/low latitudes
Arctic challenge - our research strategy for Arctic climate change
第3回極域科学シンポジウム/特別セッション「これからの北極研究」11月28日(水) 国立極地研究所 2階大会議
Dissipative Field Theory with Caldeira-Leggett Method and its Application to Disoriented Chiral Condensation
The effective field theory including the dissipative effect is developed
based on the Caldeira-Leggett theory at the classical level. After the
integration of the small field fluctuations considered as the field radiation,
the integro-differential field equation is given and shown to include the
dissipative effects. In that derivation, special cares should be taken for the
boundary condition of the integration. Application to the linear sigma model is
given, and the decay process of the chiral condensate is calculated with it,
both analytically in the linear approximation and numerically. With these
results, we discuss the stability of chiral condensates within the quenched
approximation.Comment: 16pages, ReV-Te
Relationship between retreating sea ice and trend of cloud cover over the Arctic Ocean in Coupled GCM, MIROC
第3回極域科学シンポジウム/特別セッション「これからの北極研究」11月28日(水) 国立極地研究所 2階大会議
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