| 1. |
- Chen, Zeyuan, et al.
(författare)
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Survival in the Tropics despite isolation, inbreeding and asexual reproduction : insights from the genome of the world's southernmost poplar (Populus ilicifolia)
- 2020
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Ingår i: The Plant Journal. - : Wiley. - 0960-7412 .- 1365-313X. ; 103:1, s. 430-442
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Tidskriftsartikel (refereegranskat)abstract
- Species are becoming extinct at unprecedented rates as a consequence of human activity. Hence it is important to understand the evolutionary dynamics of species with already small population sizes. Populus ilicifolia is a vulnerable poplar species that is isolated from other poplar species and is uniquely adapted to the Tropics. It has a very limited size, reproduces partly clonally and is therefore an excellent case study for conservation genomics. We present here the first annotated draft genome of P. ilicifolia, characterize genome-wide patterns of polymorphisms and compare those to other poplar species with larger natural ranges. P. ilicifolia experienced a more prolonged and severe decline of effective population size (Ne) and signs of genetic erosion than any other poplar species with which it was compared. At present, the species has the lowest genome-wide genetic diversity, the highest abundance of long runs of homozygosity, high inbreeding levels as well as a high overall accumulation of deleterious variants. However, more effective purging of severely deleterious variants and adaptation to the Tropics may have contributed to its survival. Hence, in spite of its limited genetic variation, it is certainly worth pursuing the conservation efforts of this unique species.
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| 2. |
- Chen, Weiwei, et al.
(författare)
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Lane departure warning systems and lane line detection methods based on image processing and semantic segmentation : A review
- 2020
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Ingår i: Journal of Traffic and Transportation Engineering (English Edition). - : Elsevier BV. - 2095-7564. ; 7:6, s. 748-774
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Forskningsöversikt (refereegranskat)abstract
- Recently, the development and application of lane line departure warning systems have been in the market. For any of the systems, the key part of lane line tracking, lane line identification, or lane line departure warning is whether it can accurately and quickly detect lane lines. Since 1990s, they have been studied and implemented for the situations defined by the good viewing conditions and the clear lane markings on road. After then, the accuracy for particular situations, the robustness for a wide range of scenarios, time efficiency and integration into higher-order tasks define visual lane line detection and tracking as a continuing research subject. At present, these kinds of lane marking line detection methods based on machine vision and image processing can be divided into two categories: the traditional image processing and semantic segmentation (includes deep learning) methods. The former mainly involves feature-based and model-based steps, and which can be classified into similarity- and discontinuity-based ones; and the model-based step includes different parametric straight line, curve or pattern models. The semantic segmentation includes different machine learning, neural network and deep learning methods, which is the new trend for the research and application of lane line departure warning systems. This paper describes and analyzes the lane line departure warning systems, image processing algorithms and semantic segmentation methods for lane line detection.
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| 3. |
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| 4. |
- Sun, Xuan, et al.
(författare)
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Construction of Electron Transfer Network by Self-Assembly of Self-n-Doped Fullerene Ammonium Iodide
- 2016
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 28:23, s. 8726-8731
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Tidskriftsartikel (refereegranskat)abstract
- Construction of pi-conjugation network in ordered fullerenes by self-assembly remains challenging for improving their optoelectronic performance and developing advanced materials. Here, we present a layered stacking of self-n-doped fullerene ammonium iodide (PCBANI) through a delicate balance among iodide anion-C-60 pi, electrostatic, and C-60 pi-pi interactions to construct an unprecedented supra molecular system. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and computational modeling are carried out to clarify the structure. Remarkably, the formation of intermolecular iodide anion pi interactions between iodide and the surrounded fullerene cores yields an iodide-linked C-60 pi-pi two-dimensional (2-D) network. Consequently, the ordered and tightly packed fullerenes sandwiching iodide could facilitate electron transfer along the network system. Comparative devices incorporating the disordered films show dramatically decreased current densities and manifest the importance of the pi-extended network for electron transfer. This work provides a key strategy to control the packing of ordered electron-transport materials to suppress defect formation. Moreover, engineering self-assembly of self-n-doped fullerenes with novel architectures, such as nanowire, nanotube, and nanoparticle would yield new functionalities that are suitable for photovoltaic devices, nanoelectronics, etc.
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| 5. |
- Wang, Guo-Dong, et al.
(författare)
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Out of southern East Asia : the natural history of domestic dogs across the world
- 2016
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Ingår i: Cell Research. - : Nature Publishing Group. - 1001-0602 .- 1748-7838. ; 26:1, s. 21-33
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Tidskriftsartikel (refereegranskat)abstract
- The origin and evolution of the domestic dog remains a controversial question for the scientific community, with basic aspects such as the place and date of origin, and the number of times dogs were domesticated, open to dispute. Using whole genome sequences from a total of 58 canids (12 gray wolves, 27 primitive dogs from Asia and Africa, and a collection of 19 diverse breeds from across the world), we find that dogs from southern East Asia have significantly higher genetic diversity compared to other populations, and are the most basal group relating to gray wolves, indicating an ancient origin of domestic dogs in southern East Asia 33 000 years ago. Around 15 000 years ago, a subset of ancestral dogs started migrating to the Middle East, Africa and Europe, arriving in Europe at about 10 000 years ago. One of the out of Asia lineages also migrated back to the east, creating a series of admixed populations with the endemic Asian lineages in northern China before migrating to the New World. For the first time, our study unravels an extraordinary journey that the domestic dog has traveled on earth.
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| 6. |
- Wang, Guo-dong, et al.
(författare)
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The genomics of selection in dogs and the parallel evolution between dogs and humans
- 2013
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 4, s. 1860-
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Tidskriftsartikel (refereegranskat)abstract
- The genetic bases of demographic changes and artificial selection underlying domestication are of great interest in evolutionary biology. Here we perform whole-genome sequencing of multiple grey wolves, Chinese indigenous dogs and dogs of diverse breeds. Demographic analysis show that the split between wolves and Chinese indigenous dogs occurred 32,000 years ago and that the subsequent bottlenecks were mild. Therefore, dogs may have been under human selection over a much longer time than previously concluded, based on molecular data, perhaps by initially scavenging with humans. Population genetic analysis identifies a list of genes under positive selection during domestication, which overlaps extensively with the corresponding list of positively selected genes in humans. Parallel evolution is most apparent in genes for digestion and metabolism, neurological process and cancer. Our study, for the first time, draws together humans and dogs in their recent genomic evolution.
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| 7. |
- Wang, Guangwei, et al.
(författare)
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Structural features and gasification reactivity of biomass chars pyrolyzed in different atmospheres at high temperature
- 2018
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 147, s. 25-35
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate the gasification properties of biomass chars obtained under different conditions by using non-isotherm thermogravimetric method. The physical and chemical structure features were also systematically studied. It shows that the gasification reactivities decrease with increasing pyrolysis temperature, and the gasification reactivities for the chars obtained under different atmosphere conditions are in the order of N2 char > CO2 char > CO char > H2 char. The gasification reactivities of the chars are mostly depend on the carbonaceous structure. Three nth-order represented gas-solid models, i.e. Random pore model (RPM), Unreaction core model (URCM) and Volumetric model (VM), were used to describe the reactive behaviors, and it indicates that the RPM is more suitable than the other two models.
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| 8. |
- Weixing, Wang, et al.
(författare)
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Extraction of tunnel center line and cross-sections on fractional calculus, 3D invariant moments and best-fit ellipse
- 2020
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Ingår i: Optics and Laser Technology. - : Elsevier. - 0030-3992 .- 1879-2545. ; 128
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Tidskriftsartikel (refereegranskat)abstract
- In order to measure and analyze the tunnel 3D deformation accurately, effectively and conveniently, we use the 3D point clouds instead of Total station data. A 63.6 m long tunnel was scanned twice by using a Leica C10 laser scanner (max scanning range is 300 m), for each of the scans, to obtain the accurate data and to avoid to having tunnel bending part, we divide the tunnel into five sections for the measurements, and for each measurement, the data is scanned in one station. Since the original data includes some noise, to remove noise in the point clouds, we study a new Fractional calculus template for data smoothing. After that, we propose a new method to extract the tunnel central axis based on the 3D invariant moments, and then the tunnel posture is rotated to make the central axis parallel to the reference direction, which is rotational invariant and repeatable. Based on the central axis in each section, the cross-sections are detected, and the elliptic features of a cross-section are calculated for analyzing the tunnel convergence. To make cross-section measurement rotational invariant, we apply the zeroth, the first and the second moments to obtain major and minor axes through the cross-section center. The experiment results demonstrate that this method can meet the accuracy requirements, and it can be with an accuracy of 2 mm for cross-section measurement. It is useful for tunnel engineering applications both in the tunnel 3D point cloud analysis and 3D information extraction.
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| 9. |
- Yang, Zhen, et al.
(författare)
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Elevated Serum Chemokine CXC Ligand 5 Levels Are Associated with Hypercholesterolemia But Not a Worsening of Insulin Resistance in Chinese People.
- 2010
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 95, s. 3926-3932
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Recent study showed high chemokine CXC ligand 5 (CXCL5) is thought to be associated with insulin resistance in humans. However, evidence from large-scale populations about the relationship between serum CXCL5 level and metabolic phenotypes is scarce. Here we sought to evaluate serum CXCL5 distribution and its association with metabolic phenotypes among middle-aged and older Chinese. Research Design and Methods: We evaluated serum CXCL5 in a cross-sectional sample of 3225 Chinese aged from 50 to 88 yr in a Shanghai downtown district by ELISA. Glucose, insulin, lipid profile, inflammatory marker, and adipokine were also measured. Results: The crude mean of serum CXCL5 concentrations were 1493.31 pg/ml for men and 2059.42 pg/ml for women (P < 0.001), respectively. After multiple adjustment, the odds ratios were substantially higher for hypercholesterolemia (odds ratio 3.26, 95% confidence interval 2.36-4.51) in the highest CXCL5 quartile compared with those in the lowest quartile. These associations remained significant after further adjustment for body mass index, body fat, inflammatory marker, and adipokine. However, serum resistin CXCL5 was not associated with body mass index, percent body fat, fasting glucose, insulin levels, and homeostasis model assessment index-insulin resistance (r = 0.01, 0.01, 0.01, 0.04, and 0.03, respectively; all P > 0.05). Conclusions: Elevated circulating CXCL5 concentrations were associated with higher risk of hypercholesterolemia in middle-aged and elderly Chinese independent of obesity, inflammation, adipokines, and other risk factors but not insulin resistance.
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| 10. |
- Yang, Zhen, et al.
(författare)
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Genetic variation in the GCKR gene is associated with non-alcoholic fatty liver disease in Chinese people
- 2011
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Ingår i: Molecular Biology Reports. - : Springer Science and Business Media LLC. - 0301-4851 .- 1573-4978. ; 38:2, s. 1145-1150
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Tidskriftsartikel (refereegranskat)abstract
- Recent genome-wide association studies reported that GCKR rs780094 polymorphism is associated with elevated fasting serum triglyceride levels and elevated levels of C-reactive protein (CRP). There are a ample of data on the association between circulating triglyceride, CRP concentrations and risk of non-alcoholic fatty liver (NAFLD). To determine whether the GCKR rs780094 polymorphism contributes to the development of non-alcoholic fatty liver, a case-control study was performed in 903 Chinese subjects. Among study population, 436 patients with B-mode ultrasound-proven NAFLD (318 with steatosis hepatis IA degrees, 90 with steatosis hepatis IIA degrees and 28 with steatosis hepatis IIIA degrees) and 467 controls were genotyped by using TaqMan allelic discrimination assays. We confirmed the association of GCKR rs780094 with NAFLD in Chinese people (OR = 1.607, 95% CI 1.139-2.271, P ([dom]) = 7.2 x 10(-3)). In this study, polymorphism in GCKR rs780094 was not significantly associated with the degree of fatty infiltration of the liver. In addition, the T-allele of GCKR rs780094 was significantly associated with increasing fasting triglyceride (P ([add]) = 3.8 x 10(-4)) and CRP (P ([add]) = 2.9 x 10(-4)) concentrations after adjusting for age, gender, and BMI. The association with NAFLD remained significant after adjustment for triglyceride, while adjustment for CRP abolished the association. Genetic variation in GCKR gene rs780094 polymorphism contributes to the risk of NAFLD in Chinese people. The effect of genotype on NAFLD is probably mediated through chronic low-grade systemic inflammation rather than through dislipidemia.
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