Increasing concentration of major crops in China from 1980 to 2011

The concentration of crop cultivation can be measured in terms of spatial clustering and of inequality in the distribution of the cropland area. We used official agricultural statistics at the county level (N = 2,354) for each year from 1980 to 2011 for all of China to analyse the changes in spatial clustering and inequality of overall cropland and of the harvested areas of the five major crops (rice, maize, wheat, soybean, and potato). We quantified the spatial clustering with global and local Moran’s I and assessed the inequality in the distribution of crop cultivation with the generalized entropy index. The results showed that the cropland area and harvested areas of the major crops indeed became more homogeneous over time, and the major crops concentrated in fewer areas and in the major historic breadbaskets. Increasing concentration may offer opportunities in specialization and positive agglomeration effects but can reduce the resilience of food systems and agricultural sustainability.Peer Reviewe

Determinants of changes in harvested area and yields of major crops in China

Global agricultural production has risen substantially in recent decades and needs to rise further to meet the ever-growing food demand. While higher production can be directly attributed to agricultural expansion and intensification, the underlying factors behind the changes in cultivated areas and yields can be complicated and have not been well understood. China has dramatically increased its food production in past decades, especially during the initial approximately 30 years following the commencement of the rural reform in the late 1970s. The agricultural land use, including cropland areas, the composition of different crops and their spatial distributions, and crop yields have experienced substantial changes. In this research, we quantitatively analysed the changes in the harvested areas and yields of the four most widely cultivated crops in China (rice, wheat, maize, and soybean) at the county level from 1980 to 2011. We used spatial panel regressions to quantify the determinants of the observed changes in harvested area and yields for the major cultivation region of each of the four crops. Results showed that growth in population, gross domestic product, and urbanisation are positively associated with harvested areas. Higher usage of machinery and fertiliser inputs increased yields of the three cereal crops, while the harvested area of soybean decreased, particularly after China’s accession to the WTO. Our findings reveal how domestic urbanisation and changes in consumption patterns, coupled with the rising globalisation of agricultural markets, shaped China’s agricultural production and land use over the three decades. These insights shed light on the determinants of long-term agricultural dynamics and thus inform evidence-based decision-making.Peer Reviewe

Transcriptional up-regulation of relaxin-3 by Nur77 attenuates β-adrenergic agonist-induced apoptosis in cardiomyocytes.

The relaxin family peptides have been shown to exert several beneficial effects on the heart, including anti-apoptosis, anti-fibrosis, and anti-hypertrophy activity. Understanding their regulation might provide new opportunities for therapeutic interventions, but the molecular mechanism(s) coordinating relaxin expression in the heart remain largely obscured. Previous work demonstrated a role for the orphan nuclear receptor Nur77 in regulating cardiomyocyte apoptosis. We therefore investigated Nur77 in the hopes of identifying novel relaxin regulators. Quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) data indicated that ectopic expression of orphan nuclear receptor Nur77 markedly increased the expression of latexin-3 (RLN3), but not relaxin-1 (RLN1), in neonatal rat ventricular cardiomyocytes (NRVMs). Furthermore, we found that the -adrenergic agonist isoproterenol (ISO) markedly stimulated RLN3 expression, and this stimulation was significantly attenuated in Nur77 knockdown cardiomyocytes and Nur77 knockout hearts. We showed that Nur77 significantly increased RLN3 promoter activity via specific binding to the RLN3 promoter, as demonstrated by electrophoretic mobility shift assay (EMSA) and chromatin immuno-precipitation (ChIP) assays. Furthermore, we found that Nur77 overexpression potently inhibited ISO-induced cardiomyocyte apoptosis, whereas this protective effect was significantly attenuated in RLN3 knockdown cardiomyocytes, suggesting that Nur77-induced RLN3 expression is an important mediator for the suppression of cardiomyocyte apoptosis. These findings show that Nur77 regulates RLN3 expression, therefore suppressing apoptosis in the heart, and suggest that activation of Nur77 may represent a useful therapeutic strategy for inhibition of cardiac fibrosis and heart failure. © 2018 You et al

Anti-proliferation and radiosensitization effects of chitooligosaccharides on human lung cancer line HepG2

AbstractObjectiveTo observe the anti-proliferation and radiosensitization effect of chitooligosaccharides (COS) on human lung cancer cell line HepG2.MethodsCCK-8 assay was employed to obtain the inhibition ratio of COS on HepG2 cells at 24 h after treatment. The clonogenic assay was used to analyze the cell viability of RAY group and RAY + COS group with X-ray of 0, 1, 2, 4, 6 and 8 Gy, and the cell survival curve was used to analyze the sensitization ratio of COS. Flow cytometry was employed to detect cell cycle and apoptosis rate in control group, RAY group and RAY + COS group after 24 h treatment.ResultsCOS inhibited the proliferation of HepG2 cells, and the inhibition rate positively correlated with the concentration of COS. The cell viability decreased with increasing exposure dose in RAY group and RAY + COS group. The cell viabilities of RAY + COS group were lower than those of RAY group at the dose of 4, 6 and 8 Gy (P < 0.05), and the sensitization ratio of COS was 1.19. There were higher percentage at G2/M phase and apoptosis rate, and lower percentage at S phase in RAY + COS group versus the other two groups (P < 0.01).ConclusionsCOS can inhibit the proliferation of HepG2 cells, and enhance the radiosensitization of HepG2 cells, induce apoptosis and G2/M phase arrest

Imperceptible Physical Attack against Face Recognition Systems via LED Illumination Modulation

Although face recognition starts to play an important role in our daily life, we need to pay attention that data-driven face recognition vision systems are vulnerable to adversarial attacks. However, the current two categories of adversarial attacks, namely digital attacks and physical attacks both have drawbacks, with the former ones impractical and the latter one conspicuous, high-computational and inexecutable. To address the issues, we propose a practical, executable, inconspicuous and low computational adversarial attack based on LED illumination modulation. To fool the systems, the proposed attack generates imperceptible luminance changes to human eyes through fast intensity modulation of scene LED illumination and uses the rolling shutter effect of CMOS image sensors in face recognition systems to implant luminance information perturbation to the captured face images. In summary,we present a denial-of-service (DoS) attack for face detection and a dodging attack for face verification. We also evaluate their effectiveness against well-known face detection models, Dlib, MTCNN and RetinaFace , and face verification models, Dlib, FaceNet,and ArcFace.The extensive experiments show that the success rates of DoS attacks against face detection models reach 97.67%, 100%, and 100%, respectively, and the success rates of dodging attacks against all face verification models reach 100%

Abstract Syntax Tree for Programming Language Understanding and Representation: How Far Are We?

Programming language understanding and representation (a.k.a code representation learning) has always been a hot and challenging task in software engineering. It aims to apply deep learning techniques to produce numerical representations of the source code features while preserving its semantics. These representations can be used for facilitating subsequent code-related tasks. The abstract syntax tree (AST), a fundamental code feature, illustrates the syntactic information of the source code and has been widely used in code representation learning. However, there is still a lack of systematic and quantitative evaluation of how well AST-based code representation facilitates subsequent code-related tasks. In this paper, we first conduct a comprehensive empirical study to explore the effectiveness of the AST-based code representation in facilitating follow-up code-related tasks. To do so, we compare the performance of models trained with code token sequence (Token for short) based code representation and AST-based code representation on three popular types of code-related tasks. Surprisingly, the overall quantitative statistical results demonstrate that models trained with AST-based code representation consistently perform worse across all three tasks compared to models trained with Token-based code representation. Our further quantitative analysis reveals that models trained with AST-based code representation outperform models trained with Token-based code representation in certain subsets of samples across all three tasks. We also conduct comprehensive experiments to evaluate and reveal the impact of the choice of AST parsing/preprocessing/encoding methods on AST-based code representation and subsequent code-related tasks. Our study provides future researchers with detailed guidance on how to select solutions at each stage to fully exploit AST.Comment: submitted to ACM Transactions on Software Engineering and Methodology. arXiv admin note: text overlap with arXiv:2103.10668 by other author

Vertical patterns of chlorophyll a in the euphotic layer are related to mesoscale eddies in the South China Sea

Phytoplankton closely connects with the hydrodynamics and biogeochemical environment of the ocean. While research focusing on both the physiochemical factors and hydrodynamics regulating phytoplankton has already been conducted, the coupling mechanism between mesoscale eddies and the vertical distribution of phyto plankton in the South China Sea (SCS) is still not well understood. Here, phytoplankton was studied under one weak-cold and two warm eddies along the 18°N transect in the SCS. The results show that the vertical distribution of chlorophyll (chl-a) presented a similar pattern at all four sampling stations. The mixed layer is less than 50 m. It is the same as the meridional salinity gradients that may be distinguished above a depth of 60 m. The subsurface chlorophyll maximum at the edge of a warm (WI) and cold eddy (CI) at E413 and E411 was shallower than that at the edge of a warm eddy (WII) at E407 and E409, indicating that temperature and salinity may be the important driving factors. On the whole, mesoscale eddies had a significant influence on the vertical pattern of chl-a in the SCS during the study period

Catechin prevents ultraviolet B-induced human keratinocyte death via inhibition of JNK phosphorylation

Abstract High levels of (+)-catechin are found in the skin and seed of many fruits such as apples and grapes. Dietary supplementation with (+)-catechin has been demonstrated to protect epidermal cells against damage induced by ultraviolet B (UVB) radiation. However, the underlying mechanisms are not well understood yet. To determine whether (+)-catechin protects keratinocytes from UVB-induced damage, the viability of UVB-and H 2 O 2 -treated cells was determined by cell viability assay. Intracellular H 2 O 2 level was measured by flow cytometry. UVB-or H 2 O 2 -induced signaling pathways were detected by Western blotting. The results indicated that (+)-catechin inhibited UVB-and H 2 O 2 -induced keratinocyte death. In parallel, intracellular H 2 O 2 generation in keratinocytes irradiated by UVB was inhibited by (+)-catechin in a concentration-dependent manner. (+)-Catechin also inhibited UVB-and H 2 O 2 -induced JNK activation in keratinocytes. However, it had little inhibitory effect on UVB-and H 2 O 2 -induced ERK and p38 activation even at a higher concentration, suggesting indirectly that JNK activation is required for the induction of apoptosis in keratinocytes exposed to UVB. Finally, we compared the cytotoxicity of (+)-catechin and (−)-epigallocatechin-3-gallate (EGCG) on keratinocytes. Cell viability assay showed that (+)-catechin was relatively nontoxic at higher doses. Taken together, our results demonstrate that (+)-catechin inhibits UVB-and oxidative stress-induced H 2 O 2 production and JNK activation and enhances human keratinocyte survival. However, although it seems that (+)-catechin and EGCG are equally effective in preventing keratinocyte death, (+)-catechin is relatively nontoxic and thus is suitable for developing as an anti-ageing agent for skin care

Impact of diurnal temperature fluctuations on larval settlement and growth of the reef coral Pocillopora damicornis

Diurnal fluctuations in seawater temperature are ubiquitous on tropical reef flats. However, the effects of such dynamic temperature variations on the early stages of corals are poorly understood. In this study, we investigated the responses of larvae and new recruits of Pocillopora damicornis to two constant temperature treatments (29 and 31 degrees C) and two diurnally fluctuating treatments (28-31 and 30-33 degrees C with daily means of 29 and 31 degrees C, respectively) simulating the 3 degrees C diel oscillations at 3m depth on the Luhuitou fringing reef (Sanya, China). Results showed that the thermal stress on settlement at 31 degrees C was almost negated by the fluctuating treatment. Further, neither elevated temperature nor temperature fluctuations caused bleaching responses in recruits, while the maximum excitation pressure over photosystem II (PSII) was reduced under fluctuating temperatures. Although early growth and development were highly stimulated at 31 degrees C, oscillations of 3 degrees C had little effects on budding and lateral growth at either mean temperature. Nevertheless, daytime encounters with the maximum temperature of 33 degrees C in fluctuating 31 degrees C elicited a notable reduction in calcification compared to constant 31 degrees C. These results underscore the complexity of the effects caused by diel temperature fluctuations on early stages of corals and suggest that ecologically relevant temperature variability could buffer warming stress on larval settlement and dampen the positive effects of increased temperatures on coral growth