From Jan</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2013 to Nov</span><span style="font-family:Verdana;">.<...From Jan</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2013 to Nov</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2018, we carried out the investigation on vegetation studies in the ecological monitoring programs, Shenzhen</span><span style="font-family:Verdana;"> and</span><span style="font-family:""><span style="font-family:Verdana;"> totally researched 170 plant communities of mountain areas etc., </span><span style="font-family:Verdana;">few areas of street regions and parks etc., for communities’ structural characteristics and plant diversity. We comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level and the main affected factors. We also researched and analyzed these communities’ structural characteristics and pant diversity, </span><span style="font-family:Verdana;">comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level, the main affected factors;researched and analyzed the relationship between plant community structure characteristics with the absorbing ability to PM</span><sub><span style="font-family:Verdana;">2.5</span></sub><span style="font-family:Verdana;"> pollutants. The result showed that the structure and plant diversity of natural </span><span style="font-family:Verdana;">forest </span></span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">obviously better than</span><span style="font-family:Verdana;"> artificial disturbed forest or artificial forest, the semi-natural forest w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> the middle level of the forests, In the indices of height, DBH, coverage and crow width etc. of tree layer, natural forests and semi-natural forests were obvious higher than that of artificial disturbed forest or artificial forest;in some forests of artificial disturbed forest or artificial forest, though their richness indices of family and genus were a slightly higher, but this contribution was majorly due to herb layer plants, and some shrub layer plants. Analyz</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> three kinds of communities, the number of tree layer species of natural forest was</span><span style="font-family:Verdana;"> the </span><span style="font-family:""><span style="font-family:Verdana;">largest, and their every </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity index value was </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">highest;these characteristics values of semi-natural forest were second, artificial disturbed forests or artificial forests were </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">lowest;in shrub layer, and herb layer, few </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity indices of artificial disturbed forest or artificial forest were </span><span style="font-family:Verdana;">a slightly higher than that of some natural forests, but the integral values of the diversity indices of natural forest and semi-natural forest were obvious</span></span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> higher than the former. The research showed that in the artificial disturbed forest or artificial forest, because there have some little scale clearing area</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;">, so some pioneer plant species could enter the community and formed a temporarily </span><span style="font-family:Verdana;">increase of species diversity, however</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> these species major </span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> some shrub and herb plants;but tree layer possessed obvious</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> more, even surpass</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> several ten times biomass than shrub and herb layers</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> Therefore</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the respect</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of maintain ecosystem stability and other</span><span style="font-family:Verdana;"> ecological efficient have </span><span style="font-family:Verdana;">major and dominated position and so on;and then this community can </span></span><span style="font-family:Verdana;">be </span><span style="font-family:Verdana;">natural recovery and succession, those forementioned new entire plants shall withdraw from the community and are replaced by the original plants of the community;but this process has already caused the ecological efficient loss and ecosystem unstable. Above research results are better evidence and theory reference to the argument problems on that </span><span style="font-family:Verdana;">are</span><span style="font-family:""><span style="font-family:Verdana;"> natural forest and natural restoration forest biodiversity higher? or is artificial forest biodiversity higher? and or is more artificial disturbed forest higher?</span><span style="font-family:Verdana;"> Our researches showed that used random investigation method set quadrats, and combined typical investigation method, the structural indices in the all layer of community and all diversity indices of tree, shrub and herb layers and the integral values </span></span><span style="font-family:Verdana;">were</span><span style="font-family:""><span style="font-family:Verdana;"> similar, same or usually these indices in the community which set 600 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 800 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total quatrat area were higher (</span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity) than that of more than 3000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 4000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 7000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, even more than 17,000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;">rat area of communities. These lot</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of researches further proved that according to minimum area method for vegetation survey, in subtropical region, using random investigation method combined with typical investigation set 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> - 500 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:""><span展开更多
The collision of the Indian and Eurasian plates during the Eocene represents a major tectonic shift that significantly altered biotic dynamics and promoted species diversification across the Oriental region.To explain...The collision of the Indian and Eurasian plates during the Eocene represents a major tectonic shift that significantly altered biotic dynamics and promoted species diversification across the Oriental region.To explain the diversification of taxa from the Indian subcontinent into Southeast Asia,two principal hypotheses have been proposed:the“Biotic-ferry”and“Step-stone”models.The subfamily Perittopinae,a lineage of semi-aquatic bugs comprising a single genus and 20 extant species,provides an ideal system for testing these hypotheses due to its disjunct distribution spanning the Indian subcontinent and Southeast Asia.This study conducted a comprehensive taxonomic analysis of the entire subfamily,incorporating newly defined morphological characters and multilocus phylogenetic analyses to reconstruct evolutionary relationships and historical biogeography.Morphological and phylogenetic evidence confirmed the monophyly of Perittopinae and supported the establishment of three new genera-Indoperittopus gen.nov.,Pachyperittopus gen.nov.,and Falciperittopus gen.nov.-in addition to four new species and four new combinations.Biogeographic reconstructions indicated a southern Indian origin,with initial diversification potentially occurring during the mid-Paleocene,coinciding with the major phases of the India-Eurasia collision.Subsequent range expansion over marine barriers facilitated colonization of the northern Sunda Shelf,consistent with the“Step-stone”dispersal mechanism.Later northward expansion from the southern Sunda Shelf during the early Miocene triggered further diversification of the genus Perittopus within the Indo-China Peninsula.These findings advance understanding of Perittopinae systematics,phylogeny,and historical biogeography,identifying the northward drift of the Indian plate and its eventual collision with Eurasia as catalysts of diversification within this semi-aquatic lineage.展开更多
The segmentation of unlabeled medical images is troublesome due to the high cost of annotation, and unsupervised domain adaptation is one solution to this. In this paper, an improved unsupervised domain adaptation met...The segmentation of unlabeled medical images is troublesome due to the high cost of annotation, and unsupervised domain adaptation is one solution to this. In this paper, an improved unsupervised domain adaptation method was proposed. The proposed method considered both global alignment and category-wise alignment. First, we aligned the appearance of two domains by image transformation. Second, we aligned the output maps of two domains in a global way. Then, we decomposed the semantic prediction map by category, aligning the prediction maps in a category-wise manner. Finally, we evaluated the proposed method on the 2017 Multi-Modality Whole Heart Segmentation Challenge dataset, and obtained 82.1 on the dice similarity coefficient and 4.6 on the average symmetric surface distance, demonstrating the effectiveness of the combination of global alignment and category-wise alignment.展开更多
Point cloud based place recognition plays an important role in mobile robotics. In this paper, we propose a weighted aggregation method from structure information adaptively for point cloud place recognition. Firstly,...Point cloud based place recognition plays an important role in mobile robotics. In this paper, we propose a weighted aggregation method from structure information adaptively for point cloud place recognition. Firstly, to preserve the prior distributions and local geometric structures, we fuse learned hidden features with handcrafted features in the beginning. Secondly, we further extract and aggregate adaptively weighted features concerning density and relative spatial information from these fused features, named Weighted Aggregation with Density Estimation (WADE) module. Then, we conduct the WADE block iteratively to group the latent manifold structures. Finally, comparison results on two public datasets Oxford Robotcar and KITTI show that the proposed approach exceeds the comparison approaches on recall rate averagely 7% - 8%.展开更多
目的行人检测是指使用矩形框和置信度找出图像或者视频中的所有行人。传统的图像行人检测方法对于姿态各异或者相互遮挡的行人无能为力。深度神经网络(deep neural networks,DNN)在目标检测领域表现出色,然而依然难以解决行人检测中一...目的行人检测是指使用矩形框和置信度找出图像或者视频中的所有行人。传统的图像行人检测方法对于姿态各异或者相互遮挡的行人无能为力。深度神经网络(deep neural networks,DNN)在目标检测领域表现出色,然而依然难以解决行人检测中一些问题。本文提出一种融合密度和精细分数的行人检测方法DC-CSP(density map and classifier modules with center and scale prediction)。方法首先,在CSP(center and scale prediction)网络的基础上添加密度图模块(density map module,DMM)和分类器模块(classifier module,CM),得到DC-CSP网络;然后,针对置信度不精确问题,利用不同模块对分数预测结果的互补性质,设计阶段分数融合(stage score fusion,SSF)规则对检测分数进行更新,使得行人置信度上升、背景置信度下降;最后,基于NMS(non-maximum suppression),利用估计的行人密度图,设计改进的自适应NMS(improved adaptive NMS,IAN)后处理方法,能够进一步改善检测结果,对相互遮挡行人提高交并比(intersection over union,IOU)阈值从而减少漏检,对单个行人降低IOU阈值从而减少错检。结果在公开数据集Citypersons和Caltech上进行定量和定性分析。定量分析中,与其他方法相比,本文方法在Citypersons数据集的Reasonable、Heavy、Partial以及Bare子集上,对数平均漏检率分别下降了0.8%、1.3%、1.0%和0.8%,在Caltech数据集的Reasonable和All子集上分别下降了0.3%和0.7%;在定性分析中,可视化结果表明,本文方法在一定程度上解决了各种不同场景下存在的相互遮挡行人漏检、单个行人错检以及置信度不精确等一系列问题。此外,消融实验证明了所设计模块及其对应规则的有效性。结论本文方法使用联合多个模块的卷积神经网络(convolutional neural network,CNN),针对密度特征、分类特征分别设计IAN方法和SSF规则,在一定程度上解决了相互遮挡行人漏检、单个行人错检以及置信度不精确的问题,在多个数据集上证明了方法的有效性和鲁棒性。展开更多
This study aimed to propose an operational definition of late-onset hypogonadism(LOH)that incorporates both clinical symptoms and serum testosterone measurements to evaluate the prevalence of LOH in aging males in Chi...This study aimed to propose an operational definition of late-onset hypogonadism(LOH)that incorporates both clinical symptoms and serum testosterone measurements to evaluate the prevalence of LOH in aging males in China.A population-based sample of 6296 men aged 40 years-79 years old was enrolled from six representative provinces in China.Serum total testosterone(TT),sex hormone-binding globulin(SHBG),and luteinizing hormone(LH)were measured and free testosterone(cFT)was calculated.The Aging Males’Symptoms(AMS)scale was used to evaluate the LOH symptoms.Finally,5078 men were included in this analysis.The TT levels did not decrease with age(P=0.59),and had no relationship with AMS symptoms(P=0.87 for AMS total score,P=0.74 for≥3 sexual symptoms).The cFT levels decreased significantly with age(P<0.01)and showed a negative association with the presence of≥3 sexual symptoms(P=0.03).The overall estimated prevalence of LOH was 7.8%(395/5078)if a cFT level<210 pmol l−1 combined with the presence of≥3 sexual symptoms was used as the criterion of LOH.Among them,26.1%(103/395)and 73.9%(292/395)had primary and secondary hypogonadism,respectively.After adjustment for confounding factors,primary and secondary hypogonadism was positively related to age and comorbidities.Body mass index was an independent risk factor for secondary hypogonadism.The results suggest that the AMS total score is not an appropriate indicator for decreased testosterone,and that the cFT level is more reliable than TT for LOH diagnosis.Secondary hypogonadism is the most common form of LOH.展开更多
Objective: To assess the value of intraoperative ultra- sonography in hepatobiliary surgery. Methods: Aloka-650 and Aloka-500 with a 3.5 MHz probe were used in preoperative uitrasonography and those with 5 MHz or 7.5 ...Objective: To assess the value of intraoperative ultra- sonography in hepatobiliary surgery. Methods: Aloka-650 and Aloka-500 with a 3.5 MHz probe were used in preoperative uitrasonography and those with 5 MHz or 7.5 MHz probes in intraopera- tive ultrasonography. All patients with carcinoma were confirmed pathologically. Results: In 44 patients with liver cancer (76 tumors), the diagnostic rate of intraoperative ultra- sonography was 97% (74/76), which was markedly higher than 84% (64/76) of preoperative ultra- sonography (P<0.05). The diagnostic rate (92%; 22/24) of intraoperative ultrasonography for tumors ≤2 cm in diameter was markedly higher than that (54%; 13/24) of preoperative ultrasonography (P< 0.01). The diagnostic rate (94%; 16/17) of intra- operative ultrasonography for tumor embulus of the vein was also markedly higher than that (53%; 9/ 17) of preoperative ultrasonography (P<0.01). The diagnostic rates of intraoperative and preoperative ultrasonography for cholelithiasis were 99% (108/ 109) and 97% (106/109) respectively (P>0.05). Yet the diagnostic rate (100%; 12/12) of intraopera- tive ultrasonography for gallbladder carcinoma was markedly higher than that (66.7%; 8/12) of pre- operative ultrasonography (P<0.05). The diagnos- tic rates of intraoperative ultrasonography for chole- docholith and biliary tract cancer were all 100%, markedly higher than those (83%; 20/24 and 75%; 12/16) of preoperative ultrasonography (P<0.05). Conclusions: Intraoperative ultrasonography can raise the detective rate of the liver occupying lesions comparing with that of preoperative untrasonogra- phy. It is of valuable in selecting operative scheme and locating small lesions.展开更多
Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with ...Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China.展开更多
Hyperspectral image(HSI)contains a wealth of spectral information,which makes fine classification of ground objects possible.In the meanwhile,overly redundant information in HSI brings many challenges.Specifically,the...Hyperspectral image(HSI)contains a wealth of spectral information,which makes fine classification of ground objects possible.In the meanwhile,overly redundant information in HSI brings many challenges.Specifically,the lack of training samples and the high computational cost are the inevitable obstacles in the design of classifier.In order to solve these problems,dimensionality reduction is usually adopted.Recently,graph-based dimensionality reduction has become a hot topic.In this paper,the graph-based methods for HSI dimensionality reduction are summarized from the following aspects.1)The traditional graph-based methods employ Euclidean distance to explore the local information of samples in spectral feature space.2)The dimensionality-reduction methods based on sparse or collaborative representation regard the sparse or collaborative coefficients as graph weights to effectively reduce reconstruction errors and represent most important information of HSI in the dictionary.3)Improved methods based on sparse or collaborative graph have made great progress by considering global low-rank information,local intra-class information and spatial information.In order to compare typical techniques,three real HSI datasets were used to carry out relevant experiments,and then the experimental results were analysed and discussed.Finally,the future development of this research field is prospected.展开更多
Objective To evaluate the therapeutic effects of telbivudine and entecavir on patients with chronic hepatitis B by meta-analysis method. Methods Databases including the Cochrane Library, PubMed, EMBASE and HighWire we...Objective To evaluate the therapeutic effects of telbivudine and entecavir on patients with chronic hepatitis B by meta-analysis method. Methods Databases including the Cochrane Library, PubMed, EMBASE and HighWire were searched from January 2008 to October 2012. Randomized controlled trials on treatment of chronic hepatitis B with telbivudine and entecavir were included. According to the Cochrane systematic reviews, the methodological quality of the included studies was evaluated and effective data was extracted from these studies and analyzed. Results Six studies were included eventually. The telbivudine group included 417 cases and the entecavir group included 396 cases. For 12-week antiviral treatment of chronic hepatitis B, the rate of undetectable HBV DNA was 39.1% with telbivudine and 38.6% with entecavir [OR = 1.04, 95% CI(0.62, 1.73), P > 0.05]; for treatment of HBeAg(+) hepatitis B, the HBeAg clearance rate was 23.8% with telbivudine and 3.8% with entecavir [OR= 8.07, 95% CI(2.69, 24.21), P < 0.05], and the HBeAg seroconversion rate was 6.7% with telbivudine and 3.8% with entecavir [OR = 4.95, 95% CI(1.60, 15.31), P < 0.05]; the ALT normalization rate was 54.3% with telbivudine and 58.5% with entecavir [OR = 0.84, 95% CI(0.49, 1.45), P > 0.05]; and for early-stage treatment, the incidence of adverse events was 17.2% with telbivudine and 22.0% with entecavir [OR = 0.66, 95% CI(0.33, 1.32), P > 0.05]. For 1-year antiviral treatment of chronic hepatitis B, the rate of undetectable HBV DNA was 79.4% with telbivudine and 89.7% with entecavir [OR = 0.46, 95% CI(0.28, 0.74), P < 0.05]; for treatment of HBeAg(+) hepatitis B, the HBeAg clearance rate was 28.9% with telbivudine and 15.6% with entecavir [OR = 2.21, 95% CI(1.06, 4.58), P < 0.05], and the HBeAg seroconversion rate was 31.2% with telbivudine and 18.5% with entecavir [OR = 2.31, 95% CI(1.23, 4.31), P < 0.05]; the ALT normalization rate was 85.8% with telbivudine and 84.9% with entecavir [OR = 0.90, 95% CI(0.29, 2.84), P > 0.05]; and the resistance rate was 6.0% with telbivudine and 0.76% with entecavir [OR = 5.71, 95% CI(1.67, 19.47), P < 0.05]. Conclusions For 1-year treatment of chronic hepatitis B, the difference in ALT normalization between telbivudine and entecavir was not statistically significant; and telbivudine was superior over entecavir in terms of HBeAg undetectable and HBeAg seroconversion; entecavir was superior over telbivudine in terms of HBV DNA undetectable and resistance; and both drugs had similar rates of adverse events in early-stage treatment and no severe adverse event was noted. Both telbivudine and entecavir are effective antiviral drugs against hepatitis B.展开更多
This paper introduces the use of point cloud processing for extracting 3D rock structure and the 3DEC-related reconstruction of slope failure,based on a case study of the 2019 Pinglu rockfall.The basic processing proc...This paper introduces the use of point cloud processing for extracting 3D rock structure and the 3DEC-related reconstruction of slope failure,based on a case study of the 2019 Pinglu rockfall.The basic processing procedure involves:(1)computing the point normal for HSV-rendering of point cloud;(2)automatically clustering the discontinuity sets;(3)extracting the set-based point clouds;(4)estimating of set-based mean orientation,spacing,and persistence;(5)identifying the block-forming arrays of discontinuity sets for the assessment of stability.The effectiveness of our rock structure processing has been proved by 3D distinct element back analysis.The results show that Sf M modelling and rock structure computing provides enormous cost,time and safety incentives in standard engineering practice.展开更多
As a low cost non-staple food resource,the high-viscosity paste and poor gel-forming ability of tapioca starch limit its industrial application.Herein,molasses hydrocolloids that is a by-product of the sugar refining ...As a low cost non-staple food resource,the high-viscosity paste and poor gel-forming ability of tapioca starch limit its industrial application.Herein,molasses hydrocolloids that is a by-product of the sugar refining process was applied as a blending modifier to reduce the viscosity of tapioca starch paste.The test results of paste and rheological properties show that molasses hydrocolloids exhibited a good physical viscosity-reducing effect on tapioca starch paste.The irregular network structure and high K^(+)/Ca^(2+)ion contents of molasses hydrocolloids exerted wrapping,adhesion,barrier,and hydration effects on starch,leading to the reduction of viscosity.The scanning electron microscope images and textural analysis demonstrated that this strategy also improve the structure of tapioca starch gel and enhanced its puncture strength by 75.46%.This work shows the great potential of molasses hydrocolloids as a lowcost and desirable material for the viscosity reduction of tapioca starch.展开更多
文摘From Jan</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2013 to Nov</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> 2018, we carried out the investigation on vegetation studies in the ecological monitoring programs, Shenzhen</span><span style="font-family:Verdana;"> and</span><span style="font-family:""><span style="font-family:Verdana;"> totally researched 170 plant communities of mountain areas etc., </span><span style="font-family:Verdana;">few areas of street regions and parks etc., for communities’ structural characteristics and plant diversity. We comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level and the main affected factors. We also researched and analyzed these communities’ structural characteristics and pant diversity, </span><span style="font-family:Verdana;">comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level, the main affected factors;researched and analyzed the relationship between plant community structure characteristics with the absorbing ability to PM</span><sub><span style="font-family:Verdana;">2.5</span></sub><span style="font-family:Verdana;"> pollutants. The result showed that the structure and plant diversity of natural </span><span style="font-family:Verdana;">forest </span></span><span style="font-family:Verdana;">were </span><span style="font-family:Verdana;">obviously better than</span><span style="font-family:Verdana;"> artificial disturbed forest or artificial forest, the semi-natural forest w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> the middle level of the forests, In the indices of height, DBH, coverage and crow width etc. of tree layer, natural forests and semi-natural forests were obvious higher than that of artificial disturbed forest or artificial forest;in some forests of artificial disturbed forest or artificial forest, though their richness indices of family and genus were a slightly higher, but this contribution was majorly due to herb layer plants, and some shrub layer plants. Analyz</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> three kinds of communities, the number of tree layer species of natural forest was</span><span style="font-family:Verdana;"> the </span><span style="font-family:""><span style="font-family:Verdana;">largest, and their every </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity index value was </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">highest;these characteristics values of semi-natural forest were second, artificial disturbed forests or artificial forests were </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">lowest;in shrub layer, and herb layer, few </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity indices of artificial disturbed forest or artificial forest were </span><span style="font-family:Verdana;">a slightly higher than that of some natural forests, but the integral values of the diversity indices of natural forest and semi-natural forest were obvious</span></span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> higher than the former. The research showed that in the artificial disturbed forest or artificial forest, because there have some little scale clearing area</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;">, so some pioneer plant species could enter the community and formed a temporarily </span><span style="font-family:Verdana;">increase of species diversity, however</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> these species major </span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> some shrub and herb plants;but tree layer possessed obvious</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> more, even surpass</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> several ten times biomass than shrub and herb layers</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> Therefore</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the respect</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of maintain ecosystem stability and other</span><span style="font-family:Verdana;"> ecological efficient have </span><span style="font-family:Verdana;">major and dominated position and so on;and then this community can </span></span><span style="font-family:Verdana;">be </span><span style="font-family:Verdana;">natural recovery and succession, those forementioned new entire plants shall withdraw from the community and are replaced by the original plants of the community;but this process has already caused the ecological efficient loss and ecosystem unstable. Above research results are better evidence and theory reference to the argument problems on that </span><span style="font-family:Verdana;">are</span><span style="font-family:""><span style="font-family:Verdana;"> natural forest and natural restoration forest biodiversity higher? or is artificial forest biodiversity higher? and or is more artificial disturbed forest higher?</span><span style="font-family:Verdana;"> Our researches showed that used random investigation method set quadrats, and combined typical investigation method, the structural indices in the all layer of community and all diversity indices of tree, shrub and herb layers and the integral values </span></span><span style="font-family:Verdana;">were</span><span style="font-family:""><span style="font-family:Verdana;"> similar, same or usually these indices in the community which set 600 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 800 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total quatrat area were higher (</span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-diversity) than that of more than 3000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, 4000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 7000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, even more than 17,000 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;">rat area of communities. These lot</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> of researches further proved that according to minimum area method for vegetation survey, in subtropical region, using random investigation method combined with typical investigation set 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> or 400 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> - 500 m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> total qua</span></span><span style="font-family:Verdana;">d</span><span style="font-family:""><span
基金supported by the Natural Science Foundation of Tianjin,China(24JCYBJC01910)National Natural Science Foundation of China(32322012,32470467)。
文摘The collision of the Indian and Eurasian plates during the Eocene represents a major tectonic shift that significantly altered biotic dynamics and promoted species diversification across the Oriental region.To explain the diversification of taxa from the Indian subcontinent into Southeast Asia,two principal hypotheses have been proposed:the“Biotic-ferry”and“Step-stone”models.The subfamily Perittopinae,a lineage of semi-aquatic bugs comprising a single genus and 20 extant species,provides an ideal system for testing these hypotheses due to its disjunct distribution spanning the Indian subcontinent and Southeast Asia.This study conducted a comprehensive taxonomic analysis of the entire subfamily,incorporating newly defined morphological characters and multilocus phylogenetic analyses to reconstruct evolutionary relationships and historical biogeography.Morphological and phylogenetic evidence confirmed the monophyly of Perittopinae and supported the establishment of three new genera-Indoperittopus gen.nov.,Pachyperittopus gen.nov.,and Falciperittopus gen.nov.-in addition to four new species and four new combinations.Biogeographic reconstructions indicated a southern Indian origin,with initial diversification potentially occurring during the mid-Paleocene,coinciding with the major phases of the India-Eurasia collision.Subsequent range expansion over marine barriers facilitated colonization of the northern Sunda Shelf,consistent with the“Step-stone”dispersal mechanism.Later northward expansion from the southern Sunda Shelf during the early Miocene triggered further diversification of the genus Perittopus within the Indo-China Peninsula.These findings advance understanding of Perittopinae systematics,phylogeny,and historical biogeography,identifying the northward drift of the Indian plate and its eventual collision with Eurasia as catalysts of diversification within this semi-aquatic lineage.
文摘The segmentation of unlabeled medical images is troublesome due to the high cost of annotation, and unsupervised domain adaptation is one solution to this. In this paper, an improved unsupervised domain adaptation method was proposed. The proposed method considered both global alignment and category-wise alignment. First, we aligned the appearance of two domains by image transformation. Second, we aligned the output maps of two domains in a global way. Then, we decomposed the semantic prediction map by category, aligning the prediction maps in a category-wise manner. Finally, we evaluated the proposed method on the 2017 Multi-Modality Whole Heart Segmentation Challenge dataset, and obtained 82.1 on the dice similarity coefficient and 4.6 on the average symmetric surface distance, demonstrating the effectiveness of the combination of global alignment and category-wise alignment.
文摘Point cloud based place recognition plays an important role in mobile robotics. In this paper, we propose a weighted aggregation method from structure information adaptively for point cloud place recognition. Firstly, to preserve the prior distributions and local geometric structures, we fuse learned hidden features with handcrafted features in the beginning. Secondly, we further extract and aggregate adaptively weighted features concerning density and relative spatial information from these fused features, named Weighted Aggregation with Density Estimation (WADE) module. Then, we conduct the WADE block iteratively to group the latent manifold structures. Finally, comparison results on two public datasets Oxford Robotcar and KITTI show that the proposed approach exceeds the comparison approaches on recall rate averagely 7% - 8%.
文摘目的行人检测是指使用矩形框和置信度找出图像或者视频中的所有行人。传统的图像行人检测方法对于姿态各异或者相互遮挡的行人无能为力。深度神经网络(deep neural networks,DNN)在目标检测领域表现出色,然而依然难以解决行人检测中一些问题。本文提出一种融合密度和精细分数的行人检测方法DC-CSP(density map and classifier modules with center and scale prediction)。方法首先,在CSP(center and scale prediction)网络的基础上添加密度图模块(density map module,DMM)和分类器模块(classifier module,CM),得到DC-CSP网络;然后,针对置信度不精确问题,利用不同模块对分数预测结果的互补性质,设计阶段分数融合(stage score fusion,SSF)规则对检测分数进行更新,使得行人置信度上升、背景置信度下降;最后,基于NMS(non-maximum suppression),利用估计的行人密度图,设计改进的自适应NMS(improved adaptive NMS,IAN)后处理方法,能够进一步改善检测结果,对相互遮挡行人提高交并比(intersection over union,IOU)阈值从而减少漏检,对单个行人降低IOU阈值从而减少错检。结果在公开数据集Citypersons和Caltech上进行定量和定性分析。定量分析中,与其他方法相比,本文方法在Citypersons数据集的Reasonable、Heavy、Partial以及Bare子集上,对数平均漏检率分别下降了0.8%、1.3%、1.0%和0.8%,在Caltech数据集的Reasonable和All子集上分别下降了0.3%和0.7%;在定性分析中,可视化结果表明,本文方法在一定程度上解决了各种不同场景下存在的相互遮挡行人漏检、单个行人错检以及置信度不精确等一系列问题。此外,消融实验证明了所设计模块及其对应规则的有效性。结论本文方法使用联合多个模块的卷积神经网络(convolutional neural network,CNN),针对密度特征、分类特征分别设计IAN方法和SSF规则,在一定程度上解决了相互遮挡行人漏检、单个行人错检以及置信度不精确的问题,在多个数据集上证明了方法的有效性和鲁棒性。
文摘This study aimed to propose an operational definition of late-onset hypogonadism(LOH)that incorporates both clinical symptoms and serum testosterone measurements to evaluate the prevalence of LOH in aging males in China.A population-based sample of 6296 men aged 40 years-79 years old was enrolled from six representative provinces in China.Serum total testosterone(TT),sex hormone-binding globulin(SHBG),and luteinizing hormone(LH)were measured and free testosterone(cFT)was calculated.The Aging Males’Symptoms(AMS)scale was used to evaluate the LOH symptoms.Finally,5078 men were included in this analysis.The TT levels did not decrease with age(P=0.59),and had no relationship with AMS symptoms(P=0.87 for AMS total score,P=0.74 for≥3 sexual symptoms).The cFT levels decreased significantly with age(P<0.01)and showed a negative association with the presence of≥3 sexual symptoms(P=0.03).The overall estimated prevalence of LOH was 7.8%(395/5078)if a cFT level<210 pmol l−1 combined with the presence of≥3 sexual symptoms was used as the criterion of LOH.Among them,26.1%(103/395)and 73.9%(292/395)had primary and secondary hypogonadism,respectively.After adjustment for confounding factors,primary and secondary hypogonadism was positively related to age and comorbidities.Body mass index was an independent risk factor for secondary hypogonadism.The results suggest that the AMS total score is not an appropriate indicator for decreased testosterone,and that the cFT level is more reliable than TT for LOH diagnosis.Secondary hypogonadism is the most common form of LOH.
文摘Objective: To assess the value of intraoperative ultra- sonography in hepatobiliary surgery. Methods: Aloka-650 and Aloka-500 with a 3.5 MHz probe were used in preoperative uitrasonography and those with 5 MHz or 7.5 MHz probes in intraopera- tive ultrasonography. All patients with carcinoma were confirmed pathologically. Results: In 44 patients with liver cancer (76 tumors), the diagnostic rate of intraoperative ultra- sonography was 97% (74/76), which was markedly higher than 84% (64/76) of preoperative ultra- sonography (P<0.05). The diagnostic rate (92%; 22/24) of intraoperative ultrasonography for tumors ≤2 cm in diameter was markedly higher than that (54%; 13/24) of preoperative ultrasonography (P< 0.01). The diagnostic rate (94%; 16/17) of intra- operative ultrasonography for tumor embulus of the vein was also markedly higher than that (53%; 9/ 17) of preoperative ultrasonography (P<0.01). The diagnostic rates of intraoperative and preoperative ultrasonography for cholelithiasis were 99% (108/ 109) and 97% (106/109) respectively (P>0.05). Yet the diagnostic rate (100%; 12/12) of intraopera- tive ultrasonography for gallbladder carcinoma was markedly higher than that (66.7%; 8/12) of pre- operative ultrasonography (P<0.05). The diagnos- tic rates of intraoperative ultrasonography for chole- docholith and biliary tract cancer were all 100%, markedly higher than those (83%; 20/24 and 75%; 12/16) of preoperative ultrasonography (P<0.05). Conclusions: Intraoperative ultrasonography can raise the detective rate of the liver occupying lesions comparing with that of preoperative untrasonogra- phy. It is of valuable in selecting operative scheme and locating small lesions.
基金mainly supported by National Science Fund for Distinguished Young Scholars (31625024)a grant (2008DP173354) from the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences。
文摘Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China.
基金supported by the National Key Research and Development Project(No.2020YFC1512000)the National Natural Science Foundation of China(No.41601344)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.300102320107 and 201924)in part by the General Projects of Key R&D Programs in Shaanxi Province(No.2020GY-060)Xi’an Science&Technology Project(Nos.2020KJRC0126 and 202018)。
文摘Hyperspectral image(HSI)contains a wealth of spectral information,which makes fine classification of ground objects possible.In the meanwhile,overly redundant information in HSI brings many challenges.Specifically,the lack of training samples and the high computational cost are the inevitable obstacles in the design of classifier.In order to solve these problems,dimensionality reduction is usually adopted.Recently,graph-based dimensionality reduction has become a hot topic.In this paper,the graph-based methods for HSI dimensionality reduction are summarized from the following aspects.1)The traditional graph-based methods employ Euclidean distance to explore the local information of samples in spectral feature space.2)The dimensionality-reduction methods based on sparse or collaborative representation regard the sparse or collaborative coefficients as graph weights to effectively reduce reconstruction errors and represent most important information of HSI in the dictionary.3)Improved methods based on sparse or collaborative graph have made great progress by considering global low-rank information,local intra-class information and spatial information.In order to compare typical techniques,three real HSI datasets were used to carry out relevant experiments,and then the experimental results were analysed and discussed.Finally,the future development of this research field is prospected.
文摘Objective To evaluate the therapeutic effects of telbivudine and entecavir on patients with chronic hepatitis B by meta-analysis method. Methods Databases including the Cochrane Library, PubMed, EMBASE and HighWire were searched from January 2008 to October 2012. Randomized controlled trials on treatment of chronic hepatitis B with telbivudine and entecavir were included. According to the Cochrane systematic reviews, the methodological quality of the included studies was evaluated and effective data was extracted from these studies and analyzed. Results Six studies were included eventually. The telbivudine group included 417 cases and the entecavir group included 396 cases. For 12-week antiviral treatment of chronic hepatitis B, the rate of undetectable HBV DNA was 39.1% with telbivudine and 38.6% with entecavir [OR = 1.04, 95% CI(0.62, 1.73), P > 0.05]; for treatment of HBeAg(+) hepatitis B, the HBeAg clearance rate was 23.8% with telbivudine and 3.8% with entecavir [OR= 8.07, 95% CI(2.69, 24.21), P < 0.05], and the HBeAg seroconversion rate was 6.7% with telbivudine and 3.8% with entecavir [OR = 4.95, 95% CI(1.60, 15.31), P < 0.05]; the ALT normalization rate was 54.3% with telbivudine and 58.5% with entecavir [OR = 0.84, 95% CI(0.49, 1.45), P > 0.05]; and for early-stage treatment, the incidence of adverse events was 17.2% with telbivudine and 22.0% with entecavir [OR = 0.66, 95% CI(0.33, 1.32), P > 0.05]. For 1-year antiviral treatment of chronic hepatitis B, the rate of undetectable HBV DNA was 79.4% with telbivudine and 89.7% with entecavir [OR = 0.46, 95% CI(0.28, 0.74), P < 0.05]; for treatment of HBeAg(+) hepatitis B, the HBeAg clearance rate was 28.9% with telbivudine and 15.6% with entecavir [OR = 2.21, 95% CI(1.06, 4.58), P < 0.05], and the HBeAg seroconversion rate was 31.2% with telbivudine and 18.5% with entecavir [OR = 2.31, 95% CI(1.23, 4.31), P < 0.05]; the ALT normalization rate was 85.8% with telbivudine and 84.9% with entecavir [OR = 0.90, 95% CI(0.29, 2.84), P > 0.05]; and the resistance rate was 6.0% with telbivudine and 0.76% with entecavir [OR = 5.71, 95% CI(1.67, 19.47), P < 0.05]. Conclusions For 1-year treatment of chronic hepatitis B, the difference in ALT normalization between telbivudine and entecavir was not statistically significant; and telbivudine was superior over entecavir in terms of HBeAg undetectable and HBeAg seroconversion; entecavir was superior over telbivudine in terms of HBV DNA undetectable and resistance; and both drugs had similar rates of adverse events in early-stage treatment and no severe adverse event was noted. Both telbivudine and entecavir are effective antiviral drugs against hepatitis B.
基金supported by the National Innovation Research Group Science Fund(No.41521002)the National Key Research and Development Program of China(No.2018YFC1505202)。
文摘This paper introduces the use of point cloud processing for extracting 3D rock structure and the 3DEC-related reconstruction of slope failure,based on a case study of the 2019 Pinglu rockfall.The basic processing procedure involves:(1)computing the point normal for HSV-rendering of point cloud;(2)automatically clustering the discontinuity sets;(3)extracting the set-based point clouds;(4)estimating of set-based mean orientation,spacing,and persistence;(5)identifying the block-forming arrays of discontinuity sets for the assessment of stability.The effectiveness of our rock structure processing has been proved by 3D distinct element back analysis.The results show that Sf M modelling and rock structure computing provides enormous cost,time and safety incentives in standard engineering practice.
基金supported by the National Natural Science Foundation of China(U21B2097)the National Key Research and Development Program of China(2018YFA0901500)the Jiangsu Postdoctoral Research Foundation(2019K242)。
文摘As a low cost non-staple food resource,the high-viscosity paste and poor gel-forming ability of tapioca starch limit its industrial application.Herein,molasses hydrocolloids that is a by-product of the sugar refining process was applied as a blending modifier to reduce the viscosity of tapioca starch paste.The test results of paste and rheological properties show that molasses hydrocolloids exhibited a good physical viscosity-reducing effect on tapioca starch paste.The irregular network structure and high K^(+)/Ca^(2+)ion contents of molasses hydrocolloids exerted wrapping,adhesion,barrier,and hydration effects on starch,leading to the reduction of viscosity.The scanning electron microscope images and textural analysis demonstrated that this strategy also improve the structure of tapioca starch gel and enhanced its puncture strength by 75.46%.This work shows the great potential of molasses hydrocolloids as a lowcost and desirable material for the viscosity reduction of tapioca starch.
