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Experimental hybridization and reproductive isolation between two sympatric species of tephritid fruit flies in the Anastrepha fraterculus species group

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Insect Science 2018年第6期25卷 1045-1055页

作者： juan Rull Eduardo Tadeo Rodrigo lasa Christian l.Rodriguez Alma Altuzar-Molina Martin Aluja PROIMI Biotecnologia-OONICET LIEMEN-Division Control Biologico de PlagasTucumanArgentina Red de Manejo Biorracional de Plagas y Vectores Instituto de EcologiaA.C.XalapaVeracruzMexico

Among tephritid fruit flies,hybridization has been found to produce local adaptation and speciation,and in the case of pest species,induce behavioral and ecological alterations that can adversely impact efficient pest *** species group within Anastrepha (Diptera:Tephritidae),is a rapidly radiating aggregate,which includes cryptic species complexes,numerous sister species,and several pest species. Molecular studies have highlighted the possibility of introgression between *** and *** isolation has been studied among morphotypes of the A. fraterculus species complex as a tool for species *** we examined the exis- tence and strength of prezygotic and postzygotic isolation between sympatric populations of two closely related species within the highly derivedfraterculus group (*** and ***),coexisting in *** adults of both species showed a strong tendency for assortative mating,a small proportion of hybrid pairings in both directions were *** also observed asymmetric postzygotic isolation,with one hybrid cross displaying a strong reduction in fecundity and F1 egg *** was greater for the progeny of homotypic and hybrid crosses in the maternal *** was a marked female biased sex ratio distortion for both F1 hybrid *** between *** and *** in nature may be difficult but possible;these two species display stronger reproductive isolation than all pairs of species previously examined in the *** species *** postzygotie isolation is suggestive of Wolbachia mediated cytoplasmic incompatibilities that may be exploited in area-wide pest management.

关键词： Anastrephafraterculus Anastrepha obliqua Haldane's rule introgression prezygotic isolation postzygotic isolation

Historical Sediment Record of ^(137)Cs, δ-HCH, and δ^(13)C Reflects the Impact of land Use on Soil Erosion

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Journal of Mountain Science 2014年第4期11卷 866-874页

作者： TANG Xiang-Yu ZHANG Xin-Bao GUAN Zhuo lONG Yi TANG Qiang lü Yu-juan Key laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences College of Water Resources and Architectural Engineering Northwest A&F University

This paper reports the concentrations of 137Cs, hexaehlorocyclohexane （HCH）, dichlorodiphenyltrichloroethanes （DDT） and its main degradation products, δ3C, and organic carbon in pond sediments （O-210 cm, sectioned by 2-20 cm interval） and surface soils （the 0-3 cm horizon） collected in 2OlO from Chenjia catchment, which is located in Yanting county in the hilly central Sichuan of China. α-, β-, and γ-HCH, DDT, and DDD were not detected throughout the sediment profile. Trace concentrations of δ-HCH （0.89-29.31 ng g^-1） and p,p＇- DDE （1.85-6.02 ng g^-1） were detected only in top 40 cm sediment. The 137Cs fallout peak in 1963 （corresponding to the 55-60 cm depth）, the sedimentary signature left by the last year of HCH use in 1989 （an additional indicator at 20-25 cm）, and the obvious original channel bed prior to the construction of the pond in 1956 were used as temporal markers to estimate changes in average sedimentation rate between different periods due to changes in land use. Continuous, marked decrease in average sedimentation rate （i.e., 3.79, 1.35 and 1.07 cm year-1 in 1956-1963, 1963-1989, and 1989-2010, respectively） over time was observed, probably due to the reforestation, abandoning of steep sloping farmland for afforestation and natural re-vegetation （implementation of the Grain for Green Program）, and the conversion of part of gently sloping farmlandterraces to orchard land since the 1980s, especially since the 1990s. This was corroborated by the observed decrease （more negative） in δ3C of sediment towards the surface, which indicates increased relative contribution of eroded soil particles coming from slopes with increased tree cover in sediment source area. Combined use of 137Cs, δ-HCH, and δ3C record in sediments has been demonstrated to be a powerful approach to reconstruction of response in sedimentation rate to historical land use changes.

关键词： Cesium-137 Hexaehlorocyclohexane(HCH) Sedimentation history land use

Effect of nitrogen and phosphorus on the water quality in the Three Gorges Reservoir Area during and after its construction

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Journal of Environmental Sciences 2004年第3期16卷 358-363页

作者： lIUHong lIUHui-juan QUJiu-hui StateKeylaboratoryofEnvironmentalAquaticChemistry ResearchCenterforEco-EnvironmentalSciencesChineseAcademyofSciences.Beijing100085.China

A survey concerning the concentration of the nutrients in the Three Gorges Reservoir Area was carried out. This paper presents the parameters(NO 3 - N, NO 2 - N, Kjeldahl N, non ionic ammonia, P PO 4 and TP) determined at 16 sampling sites from 1997 to 1999 The dominant soluble nitrogen form was NO 3 - N followed by Kjeldahl N, NO 2 - N and non ionic ammonia. Mean values of NO 3 - N, NO 2 - N, Kjeldahl N and non ionic ammonia ranged from 0 50 to 2 37 mg/l, 0 022 to 0 084 mg/l, 0 33 to 0 99 mg/l and 0 007 to 0 092 mg/l respectively. Mean values of P PO 4 at most sampling sites were higher than 0 1 mg/l for subject to eutrophication. The major factors influencing the concentrations of N and P might be agricultural runoff, municipal and industrial effluents. In addition, 6 kinds of soil were sampled at the area where would inundated after the dam completed. Two approaches were adopted to simulate the N and P release from the inundated soils. The results showed that the soils would release nitrogen and phosphorus to the overlying water when the soils were inundated. The characteristics of soil affected the equilibrium concentrations of N and P between the soil and the overlying water.

关键词： Three Gorges Reservoir Area nitrogen phosphorus inundated soil

Preparation and Oxidation Resistance of BN-MgAlON Composites by Hot-pressing Sintering

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Journal of Iron and Steel Research International 2015年第5期22卷 423-430页

作者： Ran lIU Xin-yuan ZHANG Xing-juan WANG Ya-na QIE Qing l Fu GAO Key laboratory for Advanced Metallurgy Technology of Ministry of Education Hebei United University College of Metallurgy and Energy Hebei United University

BN-MgA1ON composites were prepared by hot-pressing sintering under nitrogen atmosphere with BN-Mg- A1ON composite powders as raw material and Y2 O3 as sintering additive. Based on thermodynamic analysis, the oxi- dation resistance of BN-MgAION composites was investigated and the dynamics of oxidation process was also ana- lyzed. The oxidation process and the micro-morphology of the samples before and after oxidation were characterized by X-ray diffraction and scanning electron microscopy. The dynamics of oxidation resistance of the BN-MgA1ON composites was investigated via the analysis of the constant temperature oxidation mass gain curves. The results show that the main components of the material are MgA1ON, Sialon, BN and CaYAI3 07 at 1 650--1750 ＊C, and the content of CaYA1307 decreases as the sintering temperature increases. The BN-MgA1ON composites prepared at 1750 ℃ is uniform and compact with the balanced distributions of A1, Mg, O, and N. The oxidation process of BN- MgA1ON composites in air mainly consists of MgAION, Sialon and BN oxidation. The section after being oxidized at 1000--1300 ℃ involves three layers, namely, the outer layer, the middle layer and the inner layer. The oxidation process follows the parabola model. The apparent activation energy of the oxidation process is 2.13 × 10 5 J/mol and the frequency factor is 4.66 × 10 6.

关键词： boron-rich slag carbothermal reduction nitridation hot-pressing sintering BN-MgAION compositeoxidation resistance

Development of quadrilateral spline thin plate elements using the B-net method

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Acta Mechanica Sinica 2013年第4期29卷 567-574页

作者： juan Chen Chong-Jun li School of Mathematics and Quantitative Economics Dongbei University of Finance and Economics School of Mathematical Sciences Dalian University of Technology

The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh distortions. In a previous work, we constructed an 8-node quadrilateral spline element l8 using the triangular area coordinates and the B- net method, which can be insensitive to mesh distortions and possess the second order completeness in the Cartesian co- ordinates. In this paper, a thin plate spline element is devel- oped based on the spline element l8 and the refined tech- nique. Numerical examples show that the present element indeed possesses higher accuracy than the DKQ element for distorted meshes.

关键词： Spline finite element ~ Refined quadrilateral el-ement ~ Discrete Kirchhoff plate element ~ Triangular areacoordinates ~ B-net method

Drinking water production by uitrafiltration of Songhuajiang River with PAC adsorption

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Journal of Environmental Sciences 2007年第5期19卷 536-539页

作者： XIA Sheng-ji lIU Ya-nane lI Xing YAO juan-juan State Key laboratory of Pollution Control and Resources Reuse Tongji University Shanghai 200092 China School of Environmental Science and Engineering Dong Hua UniversityShanghai 201620China School of Architecture and Civil Engineering Beijing University of Technology Bejing 100083 China

In recent years, membrane ultrafiltration （UF） of surface water for drinking water treatment has become a more attractive technology worldwide as a possible alternative treatment to conventional clarification. To evaluate the performance of ultrafiltration membranes for treatment of surface water in North China, a 48-m^2 low pressure hollow fiber membrane ultrafiltration pilot plant was constructed. Ultrafiltration was operated in cross-flow and with powdered activated carbon （PAC） adsorption. Turbidity was almost completely removed to less than 0.2 NTU （below Chinese standard 1 NTU）. It was found that PAC addition enhanced organic matter removal. The combined process of PAC/UF allowed to 41% removal of CODMn, 46% removal of DOC and 57% decrease in UV254 absorbance. The elimination of particles, from average 12000/ml in the raw water to approximately 15/ml in the permeated, was observed. When PAC concentration was below 30 mg/l, backwashing could recovery the membrane flux with backwash interval/backwashing duration of 1/30.

关键词： surface water drinking water treatment ultrafiltration powdered activated carbon

Need for infliximab dose intensification in Crohn's disease and ulcerative colitis

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World Journal of Gastroenterology 2014年第27期20卷 9170-9177页

作者： Carlos Taxonera David Olivares juan l Mendoza Manuel Díaz-Rubio Enrique Rey Inflammatory Bowel Disease Unit Department of Gastroenterology Hospital Clínico San Carlos Instituto de Investigación del Hospital Clínico San Carlos (IdISSC) Department of Gastroenterology Hospital Clínico San Carlos

AIM: To compare the need for infliximab dose intensification in two cohorts of patients with Crohn’s disease (CD) or ulcerative colitis (UC).

关键词： Crohn's disease Ulcerative colitis Infliximab Dose intensification Costs

Precise drag prediction of airfoil flows by a new algebraic model

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Acta Mechanica Sinica 2020年第1期36卷 35-43页

作者： Meng-juan Xiao Zhen-Su She State Key laboratory for Turbulence and Complex Systems College of EngineeringPeking UniversityBeijing100871China

We report the results of accurate prediction of lift(C l)and drag(C D)coefficients of two typical airfoil flows(NACA0012 and RAE2822)by a new algebraic turbulence model,in which the eddy viscosity is specified by a stress length(Sl)function predicted by structural ensemble dynamics(SED)*** accuracy of the prediction of C D with error of a few counts(one count is 10−4)and of C l with error under 1%-2%are uniformly obtained for varying angles of attack(AoA),indicating an order of magnitude improvement of drag prediction accuracy compared to currently used models(typically around 20 to 30 counts).More interestingly,the SED-Sl model is distinguished with fewer parameters of clear physical meaning,which quantify underlying turbulent boundary layer(TBl)with a universal multi-layer structure,and is thus promising to be more easily generalizable to complex *** use of the new model for the calibration of flow condition in experiment and the extraction of flow physics from numerical simulation data of aeronautic flows are discussed.

关键词： lift and drag coefficients Airfoil Flows Stress length Structural ensemble dynamics

On the role of endogenous neurotoxins and neuroprotection in Parkinson's disease

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Neural Regeneration Research 2017年第6期12卷 897-901页

作者： juan Segura-Aguilar Molecular and Clinical Pharmacology ICBM Faculty of Medicine University of Chile

For 50 years ago was introduced l-3,4-dihydroxyphenylalanine（l-dopa） in Parkinson＇s disease treatment and during this significant advances has been done but what trigger the degeneration of the nigrostriatal system remain unknown. There is a general agreement in the scientific community that mitochondrial dysfunction, protein degradation dysfunction, alpha-synuclein aggregation to neurotoxic oligomers, neuroinflammation, oxidative and endoplasmic reticulum stress are involved in the loss of dopaminergic neurons containing neuromelanin in Parkinson＇s disease. The question is what triggers these mechanisms. The age of normal onset in idiopathic Parkinson＇s disease suggests that environmental factors such as metals, pollutants or genetic mutations cannot be involved because these factors are related to early onset of Parkinsonism. Therefore, we have to search for endogenous neurotoxins and neuroprotection in order to understand what trigger the loss of dopaminergic neurons. One important feature of Parkinson＇s disease is the rate of the degenerative process before the motor symptoms are evident and during the disease progression. The extremely slow rate of Parkinson＇s disease suggests that the neurotoxins and the neuroprotection have to be related to dopamine metabolism. Possible candidates for endogenous neurotoxins are alpha-synuclein neurotoxic oligomers, 4-dihydroxyphenylacetaldehyde and ortho-quinones formed during dopamine oxidation to neuromelanin. Vesicular monoamine transporter-2, DT-diaphorase and glutathione transferase M2-2 seems to be the most important neuroprotective mechanism to prevent neurotoxic mechanism during dopamine oxidation.

关键词： dopamine endogenous endoplasmic degeneration reticulum extremely glutathione Dopamine transporter metabolism