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Spatiotemporal distributions of cloud properties over China based on Himawari-8 advanced Himawari imager data 期刊论文
ATMOSPHERIC RESEARCH, 2020, 240
作者:  Yang, Yikun;  Zhao, Chuanfeng;  Fan, Hao
收藏  |  浏览/下载:20/0  |  提交时间:2020/08/18
Cloud fraction  Cloud top height  Cloud top temperature  Cloud optical thickness  Himawari-8  Diurnal variation  
Diurnal Cycle of Precipitation Over the Maritime Continent Under Modulation of MJO: Perspectives From Cloud-Permitting Scale Simulations 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (13)
作者:  Wei, Yuntao;  Pu, Zhaoxia;  Zhang, Chidong
收藏  |  浏览/下载:10/0  |  提交时间:2020/08/18
tropical convection  diurnal cycle of precipitation  cloud-permitting simulation  MJO  
Evaluation of an Improved Convective Triggering Function: Observational Evidence and SCM Tests 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (11)
作者:  Wang, Yi-Chi;  Xie, Shaocheng;  Tang, Shuaiqi;  Lin, Wuyin
收藏  |  浏览/下载:11/0  |  提交时间:2020/08/18
convection trigger  convection  diurnal cycle of precipitation  E3SM  precipitation  single-column model  
Nearest neighbours reveal fast and slow components of motor learning 期刊论文
NATURE, 2020, 577 (7791) : 526-+
作者:  Kollmorgen, Sepp;  Hahnloser, Richard H. R.;  Mante, Valerio
收藏  |  浏览/下载:5/0  |  提交时间:2020/07/03

A new method for analysing change in high-dimensional data is based on nearest-neighbour statistics and is applied here to song dynamics during vocal learning in zebra finches, but could potentially be applied to other biological and artificial behaviours.


Changes in behaviour resulting from environmental influences, development and learning(1-5) are commonly quantified on the basis of a few hand-picked features(2-4,6,7) (for example, the average pitch of acoustic vocalizations(3)), assuming discrete classes of behaviours (such as distinct vocal syllables)(2,3,8-10). However, such methods generalize poorly across different behaviours and model systems and may miss important components of change. Here we present a more-general account of behavioural change that is based on nearest-neighbour statistics(11-13), and apply it to song development in a songbird, the zebra finch(3). First, we introduce the concept of '  repertoire dating'  , whereby each rendition of a behaviour (for example, each vocalization) is assigned a repertoire time, reflecting when similar renditions were typical in the behavioural repertoire. Repertoire time isolates the components of vocal variability that are congruent with long-term changes due to vocal learning and development, and stratifies the behavioural repertoire into '  regressions'  , '  anticipations'  and '  typical renditions'  . Second, we obtain a holistic, yet low-dimensional, description of vocal change in terms of a stratified '  behavioural trajectory'  , revealing numerous previously unrecognized components of behavioural change on fast and slow timescales, as well as distinct patterns of overnight consolidation(1,2,4,14,15) across the behavioral repertoire. We find that diurnal changes in regressions undergo only weak consolidation, whereas anticipations and typical renditions consolidate fully. Because of its generality, our nonparametric description of how behaviour evolves relative to itself-rather than to a potentially arbitrary, experimenter-defined goal(2,3,14,16)-appears well suited for comparing learning and change across behaviours and species(17,18), as well as biological and artificial systems(5).


  
Nitric Oxide Abundance in the Martian Thermosphere and Its Diurnal Variation 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (9)
作者:  Cui, J.;  Fu, M-H;  Ren, Z-P;  Gu, H.;  Guo, J-H;  Wu, X-S;  Wu, Z-P;  Lai, H-R;  Wei, Y.
收藏  |  浏览/下载:11/0  |  提交时间:2020/07/02
nitric oxide  Mars  diurnal variation  Mass spectrometer  thermosphere  
Convection Initiation in Monsoon Coastal Areas (South China) 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (11)
作者:  Bai, Lanqiang;  Chen, Guixing;  Huang, Ling
收藏  |  浏览/下载:5/0  |  提交时间:2020/05/13
convection initiation  monsoon  coast  radar  rainfall  diurnal cycle  
Contrasting frontal and warm-sector heavy rainfalls over South China during the early-summer rainy season 期刊论文
ATMOSPHERIC RESEARCH, 2020, 235
作者:  Wu, Naigeng;  Ding, Xi;  Wen, Zhiping;  Chen, Guixing;  Meng, Zhiyong;  Lin, Liangxun;  Min, Jinzhong
收藏  |  浏览/下载:10/0  |  提交时间:2020/07/02
Warm-sector heavy rainfall  Frontal heavy rainfall  Monsoon  Land-sea breeze  Diurnal variation  Early-summer rainy season  
Potential circadian effects on translational failure for neuroprotection 期刊论文
NATURE, 2020
作者:  Sakai, Akito;  Minami, Susumu;  Koretsune, Takashi;  Chen, Taishi;  Higo, Tomoya;  Wang, Yangming;  Nomoto, Takuya;  Hirayama, Motoaki;  Miwa, Shinji;  Nishio-Hamane, Daisuke;  Ishii, Fumiyuki;  Arita, Ryotaro;  Nakatsuji, Satoru
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/03

Neuroprotectant strategies that have worked in rodent models of stroke have failed to provide protection in clinical trials. Here we show that the opposite circadian cycles in nocturnal rodents versus diurnal humans(1,2) may contribute to this failure in translation. We tested three independent neuroprotective approaches-normobaric hyperoxia, the free radical scavenger alpha-phenyl-butyl-tert-nitrone (alpha PBN), and the N-methyl-d-aspartic acid (NMDA) antagonist MK801-in mouse and rat models of focal cerebral ischaemia. All three treatments reduced infarction in day-time (inactive phase) rodent models of stroke, but not in night-time (active phase) rodent models of stroke, which match the phase (active, day-time) during which most strokes occur in clinical trials. Laser-speckle imaging showed that the penumbra of cerebral ischaemia was narrower in the active-phase mouse model than in the inactive-phase model. The smaller penumbra was associated with a lower density of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL)-positive dying cells and reduced infarct growth from 12 to 72 h. When we induced circadian-like cycles in primary mouse neurons, deprivation of oxygen and glucose triggered a smaller release of glutamate and reactive oxygen species, as well as lower activation of apoptotic and necroptotic mediators, in '  active-phase'  than in '  inactive-phase'  rodent neurons. alpha PBN and MK801 reduced neuronal death only in '  inactive-phase'  neurons. These findings suggest that the influence of circadian rhythm on neuroprotection must be considered for translational studies in stroke and central nervous system diseases.


Studies in rats and mice at different times of day suggest that the failure of neuroprotective strategies for stroke in translational studies might be related to the difference in circadian cycles between humans and rodents.


  
Ground-Based Observations Reveal Unique Valley Precipitation Patterns in the Central Himalaya 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (5)
作者:  Ouyang, Lin;  Yang, Kun;  Lu, Hui;  Chen, Yingying;  Lazhu;  Zhou, Xu;  Wang, Yan
收藏  |  浏览/下载:8/0  |  提交时间:2020/07/02
precipitation  diurnal cycle  seasonal variation  central Himalaya  
Highly porous nature of a primitive asteroid revealed by thermal imaging 期刊论文
NATURE, 2020, 579 (7800) : 518-522
作者:  Quinn, Robert A.;  Melnik, Alexey, V;  Vrbanac, Alison;  Fu, Ting;  Patras, Kathryn A.;  Christy, Mitchell P.;  Bodai, Zsolt;  Belda-Ferre, Pedro;  Tripathi, Anupriya;  Chung, Lawton K.;  Downes, Michael;  Welch, Ryan D.;  Quinn, Melissa;  Humphrey, Greg;  Panitchpakdi, Morgan;  Weldon, Kelly C.;  Aksenov, Alexander;  da Silva, Ricardo;  Avila-Pacheco, Julian;  Clish, Clary;  Bae, Sena;  Mallick, Himel;  Franzosa, Eric A.;  Lloyd-Price, Jason;  Bussell, Robert;  Thron, Taren;  Nelson, Andrew T.;  Wang, Mingxun;  Leszczynski, Eric;  Vargas, Fernando;  Gauglitz, Julia M.;  Meehan, Michael J.;  Gentry, Emily;  Arthur, Timothy D.;  Komor, Alexis C.;  Poulsen, Orit;  Boland, Brigid S.;  Chang, John T.;  Sandborn, William J.;  Lim, Meerana;  Garg, Neha;  Lumeng, Julie C.;  Xavier, Ramnik J.;  Kazmierczak, Barbara, I;  Jain, Ruchi;  Egan, Marie;  Rhee, Kyung E.;  Ferguson, David;  Raffatellu, Manuela;  Vlamakis, Hera;  Haddad, Gabriel G.;  Siegel, Dionicio;  Huttenhower, Curtis;  Mazmanian, Sarkis K.;  Evans, Ronald M.;  Nizet, Victor;  Knight, Rob;  Dorrestein, Pieter C.
收藏  |  浏览/下载:56/0  |  提交时间:2020/05/13

Carbonaceous (C-type) asteroids(1) are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites(2,3) and are essential for understanding planetary formation processes. However, their physical properties remain poorly known because carbonaceous chondrite meteoroids tend not to survive entry to Earth'  s atmosphere. Here we report on global one-rotation thermographic images of the C-type asteroid 162173 Ryugu, taken by the thermal infrared imager (TIR)(4) onboard the spacecraft Hayabusa2(5), indicating that the asteroid'  s boulders and their surroundings have similar temperatures, with a derived thermal inertia of about 300 J m(-2) s(-0.5) K-1 (300 tiu). Contrary to predictions that the surface consists of regolith and dense boulders, this low thermal inertia suggests that the boulders are more porous than typical carbonaceous chondrites(6) and that their surroundings are covered with porous fragments more than 10 centimetres in diameter. Close-up thermal images confirm the presence of such porous fragments and the flat diurnal temperature profiles suggest a strong surface roughness effect(7,8). We also observed in the close-up thermal images boulders that are colder during the day, with thermal inertia exceeding 600 tiu, corresponding to dense boulders similar to typical carbonaceous chondrites(6). These results constrain the formation history of Ryugu: the asteroid must be a rubble pile formed from impact fragments of a parent body with microporosity(9) of approximately 30 to 50 per cent that experienced a low degree of consolidation. The dense boulders might have originated from the consolidated innermost region or they may have an exogenic origin. This high-porosity asteroid may link cosmic fluffy dust to dense celestial bodies(10).


Thermal imaging data obtained from the spacecraft Hayabusa2 reveal that the carbonaceous asteroid 162173 Ryugu is an object of unusually high porosity.