End-to-End Entity Detection with Proposer and Regressor

Named entity recognition is a traditional task in natural language processing. In particular, nested entity recognition receives extensive attention for the widespread existence of the nesting scenario. The latest research migrates the well-established paradigm of set prediction in object detection to cope with entity nesting. However, the manual creation of query vectors, which fail to adapt to the rich semantic information in the context, limits these approaches. An end-to-end entity detection approach with proposer and regressor is presented in this paper to tackle the issues. First, the proposer utilizes the feature pyramid network to generate high-quality entity proposals. Then, the regressor refines the proposals for generating the final prediction. The model adopts encoder-only architecture and thus obtains the advantages of the richness of query semantics, high precision of entity localization, and easiness of model training. Moreover, we introduce the novel spatially modulated attention and progressive refinement for further improvement. Extensive experiments demonstrate that our model achieves advanced performance in flat and nested NER, achieving a new state-of-the-art F1 score of 80.74 on the GENIA dataset and 72.38 on the WeiboNER dataset

Abrupt drainage basin reorganization following a Pleistocene river capture

River capture is a dramatic natural process of internal competition through which mountainous landscapes evolve and respond to perturbations in tectonics and climate. River capture may occur when one river network grows at the expense of another, resulting in a victor that steals the neighboring headwaters. While river capture occurs regularly in numerical models, field observations are rare. Here we document a late Pleistocene river capture in the Yimeng Mountains, China that abruptly shifted 25 km^2 of drainage area from one catchment to another. River terraces and imbricated cobbles indicate that the main channel incised 27 m into granitic bedrock within 80 kyr, following the capture event, and upstream propagating knickpoints and waterfalls reversed the flow direction of a major river. Topographic analysis shows that the capture shifted the river basins far from topographic equilibrium, and active divide migration is propagating the effects of the capture throughout the landscape

ZmCom1 Is Required for Both Mitotic and Meiotic Recombination in Maize

CtIP/Ctp1/Sae2/Com1, a highly conserved protein from yeast to higher eukaryotes, is required for DNA double-strand break repair through homologous recombination (HR). In this study, we identified and characterized the COM1 homolog in maize. The ZmCom1 gene is abundantly expressed in reproductive tissues at meiosis stages. In ZmCom1-deficient plants, meiotic chromosomes are constantly entangled as a formation of multivalents and accompanied with chromosome fragmentation at anaphase I. In addition, the formation of telomere bouquet, homologous pairing and synapsis were disturbed. The immunostaining assay showed that the localization of ASY1 and DSY2 was normal, while ZYP1 signals were severely disrupted in Zmcom1 meiocytes, indicating that ZmCom1 is critically required for the proper SC assembly. Moreover, RAD51 signals were almost completely absent in Zmcom1 meiocytes, implying that COM1 is required for RAD51 loading. Surprisingly, in contrast to the Atcom1 and Oscom1 mutants, Zmcom1 mutant plants exhibited a number of vegetative phenotypes under normal growth condition, which may be partly attributed to mitotic aberrations including chromosomal fragmentation and anaphase bridges. Taken together, our results suggest that although the roles of COM1 in HR process seem to be primarily conserved, the COM1 dysfunction can result in the marked dissimilarity in mitotic and meiotic outcomes in maize compared to Arabidopsis and rice. We suggest that this character may be related to the discrete genome context

Abrupt drainage basin reorganization following a Pleistocene river capture

River capture is a dramatic natural process of internal competition through which mountainous landscapes evolve and respond to perturbations in tectonics and climate. River capture may occur when one river network grows at the expense of another, resulting in a victor that steals the neighboring headwaters. While river capture occurs regularly in numerical models, field observations are rare. Here we document a late Pleistocene river capture in the Yimeng Mountains, China that abruptly shifted 25 km^2 of drainage area from one catchment to another. River terraces and imbricated cobbles indicate that the main channel incised 27 m into granitic bedrock within 80 kyr, following the capture event, and upstream propagating knickpoints and waterfalls reversed the flow direction of a major river. Topographic analysis shows that the capture shifted the river basins far from topographic equilibrium, and active divide migration is propagating the effects of the capture throughout the landscape

Response of Runoff-Sediment System to Vegetation Variation in the Yellow River Basin in the Last 20 Years

The Yellow River basin suffers from the most serious soil erosion of any area in the world. It is also a key area for soil–water conservation and ecological protection in China. It is important to determine the status of the ecological protection of the Yellow River basin in recent years. We examined the vegetation patterns and spatio-temporal changes in runoff sediment in the Yellow River basin in the last 20 years. The results can provide a sound basis for regional ecological management. Vegetation coverage in the Yellow River basin has increased in the last two decades. The natural runoff has more than doubled over this time and the runoff coefficient has increased by more than 30%. However, the growth in the measured runoff has significantly weakened owing to continually high water consumption. The sediment concentration from Toudaoguai to Tongguan has decreased by 74.11% and the sediment modulus has decreased by 34.75%. Ecological protection of the Yellow River has significantly improved the vegetation coverage since 2000. The functions of water and soil conservation have improved, but the latter function needs to be strengthened. In addition, measures for ecological protection are needed to strengthen the overall management of water resources

Should Desert and Desertification Regions Be Confused? New Insights Based on Vegetation Quality and Its Inter-Decadal Variations

As the most unique ecosystem on the Earth’s surface, desert and desertification region cannot be confused. The current research on spatial distinction of desert and desertification region is still lacking. Based on NDVI (normalized difference vegetation index) data from 1998 to 2020, we aimed to distinguish the differences between desert and desertification region. Improvement and degradation of vegetation quality in China have coexisted in the past 20 years. Within the low value classification in 1998, the regions where vegetation quality remained High increase were mainly concentrated in Loess Plateau. Within the medium value classification in 1998, the High increase classifications were mainly distributed in the west of the Taihang Mountains, north of the Qinling–Daba Mountains, east of the Qinghai–Tibet Plateau, Yunnan–Guizhou Plateau, and the Northeast Plain. Within the high value classification in 1998, the High increase classification was distributed in the south of the Yangtze River. In 1998 and 2020, China had a total area of 2.50 million km2 of desert regions, accounting for 26% of China’s land area. After 20 years of large-scale ecological protection, desert regions have hardly undergone significant changes. Desertification regions decreased from 2.80 million km2 to 1.67 million km2, a decrease of 40.3%

Grain Security in Light of the Current Geopolitical Background and Agricultural Policy in the Democratic People’s Republic of Korea

Grain problems in the Democratic People’s Republic of Korea (DPRK) have been the focus of global attention for many years. In this context, scientific evaluations of grain supply and consumption are very important as a component of agricultural cooperation between China and the DPRK and will also promote a stable development of the society across Northeast Asia. The results of this analysis showed that DPRK grain production in 2019 was equivalent to that seen in 1975. Dominant grain-producing areas within the DPRK include the plains in the west and southwest encompassing North Phyongan, South Phyongan, Pyongyang, North Hwanghae, and South Hwanghae. The data showed that the DPRK was basically grain self-sufficient prior to 1995 but subsequently has been unable to meet the demand, even given reliance on imports and international assistance. The cultivated land area within the DPRK includes large proportions of slope farmland, an important factor that influences the grain production. The DPRK also boasts good irrigation infrastructure that provides a good basis for grain production. This means that, under normal circumstances, 56.59% of cultivated land can be effectively irrigated. Chemical fertilizer supplies have, however, been unable to meet the agricultural production demands, currently remaining at the 1970s levels. It is clear that the DPRK needs to increase chemical and organic fertilizer inputs in order to ensure soil fertility. As the southern region of the DPRK has sufficient water and is hot enough, the implementation of multi-cropping farming systems will ensure an increase of at least 4.9 million tons in grain production and will guarantee supply for at least 1.88 million people

Grain Security in Light of the Current Geopolitical Background and Agricultural Policy in the Democratic People’s Republic of Korea

Grain problems in the Democratic People’s Republic of Korea (DPRK) have been the focus of global attention for many years. In this context, scientific evaluations of grain supply and consumption are very important as a component of agricultural cooperation between China and the DPRK and will also promote a stable development of the society across Northeast Asia. The results of this analysis showed that DPRK grain production in 2019 was equivalent to that seen in 1975. Dominant grain-producing areas within the DPRK include the plains in the west and southwest encompassing North Phyongan, South Phyongan, Pyongyang, North Hwanghae, and South Hwanghae. The data showed that the DPRK was basically grain self-sufficient prior to 1995 but subsequently has been unable to meet the demand, even given reliance on imports and international assistance. The cultivated land area within the DPRK includes large proportions of slope farmland, an important factor that influences the grain production. The DPRK also boasts good irrigation infrastructure that provides a good basis for grain production. This means that, under normal circumstances, 56.59% of cultivated land can be effectively irrigated. Chemical fertilizer supplies have, however, been unable to meet the agricultural production demands, currently remaining at the 1970s levels. It is clear that the DPRK needs to increase chemical and organic fertilizer inputs in order to ensure soil fertility. As the southern region of the DPRK has sufficient water and is hot enough, the implementation of multi-cropping farming systems will ensure an increase of at least 4.9 million tons in grain production and will guarantee supply for at least 1.88 million people

Dynamic assessment of the COVID-19 lockdown in the Xinjiang region using night-time light remote sensing

ABSTRACTChina used to have the world’s most stringent prevention policies during the COVID-19 pandemic. The strict lockdown in Xinjiang region in 2022 was considered to be the longest in the process of COVID-19 pandemic prevention. Therefore, we examined the dynamic effects of the COVID-19 lockdown in Xinjiang region using night-time light data. The findings showed that before the outbreak of COVID-19, the night-time light in Xinjiang region still maintained a significant growth. However, after the lockdown of COVID-19 in August 2022, the night-time light showed a significant decrease, especially in August. Urumqi's night-time light decreased by at least 25% compared to the non-lockdown, while that in other major cities was between 5% and 15%. After the lockdown was lifted in November 2022, the night-time light in Urumqi increased by at least 50% compared to the lockdown, while that in other major cities was generally less than 30%. The regions where night-time light decreased in Urumqi were mainly within a radius of 40 km, whereas that in other cities were mainly concentrated within a radius of 6 km. The changes in statistical data and night-time light indicated that the economic activities in Xinjiang region were significantly affected by the COVID-19 lockdown