Model–proxy comparison for overshoot phenomenon of Atlantic thermohaline circulation at Bφlling–Allerφd

The overshoot phenomenon of the Atlantic thermohaline circulation （THC） is a transient climate response to meltwater forcing and could induce intense climate change by increasing the magnitudes of Atlantic THC changes at the end of meltwater discharges. This phenomenon was formally presented with the successfully simulated Bolling-Allerod （BA） event in the first transient simulation of the last deglaciation with fully coupled model NCAR-CCSM3 （TraCE-21K）. Currently, not all proxy records of Atlantic THC support the occurrence of the THC overshoot at BA. Commonly used THC proxy from Bermuda Rise （GGC5） does not exhibit THC overshoot at BA but other proxies such as TTR-451 at Eirik Drift do. How to interpret this regional discrepancy of proxy records is a key question for the validation of the Atlantic THC overshoot at BA. Here, we show that the vigor of deep circulation varies regionally during the Atlantic THC overshoot at BA in TraCE-21K simulation, and this regional discrepancy in the simulation is consistent with that in the marine sediment records in North Atlantic. The consistent model-proxy evidence supports the occurrence of Atlantic THC overshoot at BA.     

Insect behaviour: arboreal ants build traps to capture prey

To meet their need for nitrogen in the restricted foraging environment provided by their host plants, some arboreal ants deploy group ambush tactics in order to capture flying and jumping prey that might otherwise escape. Here we show that the ant Allomerus decemarticulatus uses hair from the host plant's stem, which it cuts and binds together with a purpose-grown fungal mycelium, to build a spongy 'galleried' platform for trapping much larger insects. Ants beneath the platform reach through the holes and immobilize the prey, which is then stretched, transported and carved up by a swarm of nestmates. To our knowledge, the collective creation of a trap as a predatory strategy has not been described before in ants.     

Somatic and germline activating mutations of the ALK kinase receptor in neuroblastoma

Neuroblastoma, a tumour derived from the peripheral sympathetic nervous system, is one of the most frequent solid tumours in childhood. It usually occurs sporadically but familial cases are observed, with a subset of cases occurring in association with congenital malformations of the neural crest being linked to germline mutations of the PHOX2B gene. Here we conducted genome-wide comparative genomic hybridization analysis on a large series of neuroblastomas. Copy number increase at the locus encoding the anaplastic lymphoma kinase (ALK) tyrosine kinase receptor was observed recurrently. One particularly informative case presented a high-level gene amplification that was strictly limited to ALK, indicating that this gene may contribute on its own to neuroblastoma development. Through subsequent direct sequencing of cell lines and primary tumour DNAs we identified somatic mutations of the ALK kinase domain that mainly clustered in two hotspots. Germline mutations were observed in two neuroblastoma families, indicating that ALK is a neuroblastoma predisposition gene. Mutated ALK proteins were overexpressed, hyperphosphorylated and showed constitutive kinase activity. The knockdown of ALK expression in ALK-mutated cells, but also in cell lines overexpressing a wild-type ALK, led to a marked decrease of cell proliferation. Altogether, these data identify ALK as a critical player in neuroblastoma development that may hence represent a very attractive therapeutic target in this disease that is still frequently fatal with current treatments.     

绥阳双河洞国家地质公园边界优化

双河洞是世界上最长的白云岩洞系,它构成了绥阳双河洞国家地质公园的主体。随着探测长度的持续增长,现行园区边界已不能满足保护与管理的需求。以双河洞空间分布为参考,运用ArcGIS水文与空间分析工具对池武溪流域及周边数字高程模型(digital elevation model, DEM)数据进行数字河网提取、地表流域分割,并综合考虑自然与人文因素,得到如下认识：(1)园区1∶5万DEM精度下设定1 000 m²的汇流累积量阈值模拟出的数字水系与真实水系一致性高;(2)双河洞系统跨越池武溪地表分水岭,直观反映了地表-地下分水岭不重合的现象;(3)双河洞系统自2018年就已超越现行地质公园边界以及县级行政区界线,核心地质遗迹保护与管理存在真空地带,园区边界优化调整迫在眉睫;(4)园区边界应结合双河洞系统发育界限预判为考量适时进行动态调整,并提出了初步的优化定界方案;(5)未来应加强双河洞区域的示踪试验,更加明确地下分水岭范围,以更加科学、完整地划定园区边界。     

Genome-wide atlas of gene expression in the adult mouse brain

Molecular approaches to understanding the functional circuitry of the nervous system promise new insights into the relationship between genes, brain and behaviour. The cellular diversity of the brain necessitates a cellular resolution approach towards understanding the functional genomics of the nervous system. We describe here an anatomically comprehensive digital atlas containing the expression patterns of approximately 20,000 genes in the adult mouse brain. Data were generated using automated high-throughput procedures for in situ hybridization and data acquisition, and are publicly accessible online. Newly developed image-based informatics tools allow global genome-scale structural analysis and cross-correlation, as well as identification of regionally enriched genes. Unbiased fine-resolution analysis has identified highly specific cellular markers as well as extensive evidence of cellular heterogeneity not evident in classical neuroanatomical atlases. This highly standardized atlas provides an open, primary data resource for a wide variety of further studies concerning brain organization and function.