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Alignment between galaxies and large-scale structure

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Chinese Journal of Astronomy and Astrophysics 2009年第1期9卷 41-58页

作者： A. Faltenbacher Cheng Li simon d. M. White Yi-Peng Jing Shu-de Mao Jie Wang Max-Planck-Institute for Astrophysics Karl-Schwarzschild-Str. 1 D-85741 Garching Germany MPA/SHAO Joint Center for Astrophysical Cosmology at Shanghai Astronomical Observatory Shanghai 200030 China Jodrell Bank Centre for Astrophysl＇cs Alan Turing Building The University of Manchester Manchester M13 9PL UK department of Physics Institute of Computational Cosmology University of Durham Science Laboratories South Road Durham DH1 3LE UK

Based on the Sloan digital Sky Survey dR6 （SdSS） and the ＇Millennium Simulation （MS）, we investigate the alignment between galaxies and large-scale structure. For this purpose, we develop two new statistical tools, namely the alignment correlation function and the cos（20）-statistic. The former is a two-dimensional extension of the traditional two-point correlation function and the latter is related to the ellipticity correlation function used for cosmic shear measurements. Both are based on the cross correlation between a sample of galaxies with orientations and a reference sample which represents the large-scale structure. We apply the new statistics to the SdSS galaxy catalog. The alignment correlation function reveals an overabundance of reference galaxies along the major axes of red, luminous （L 〉～L＊） galaxies out to projected separations of 60 h-lMpc. The signal increases with central galaxy luminosity. No alignment signal is detected for blue galaxies. The cos（2θ）-statistic yields very similar results. Starting from a MS semi-analytic galaxy catalog, we assign an orientation to each red, luminous and central galaxy, based on that of the central region of the host halo （with size similar to that of the stellar galaxy）. As an alternative, we use the orientation of the host halo itself. We find a mean projected misalignment between a halo and its central region of -25°. The misalignment decreases slightly with increasing luminosity of the central galaxy. Using the orientations and luminosities of the semi-analytic galaxies, we repeat our alignment analysis on mock surveys of the MS. Agreement with the SdSS results is good if the central orientations are used. Predictions using the halo orientations as proxies for cen- tral galaxy orientations overestimate the observed alignment by more than a factor of 2. Finally, the large volume of the MS allows us to generate a two-dimensional map of the alignment correlation function, which shows the reference galaxy distrib

关键词： dark matter halos clustering-galaxies large-scale structure of Universe- cosmology theory -dark matter

A high incidence of non-cavity nesting in an introduced population of House Sparrows suggests that the species should not be constrained by cavity-nest site availability

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Avian Research 2017年第4期8卷 202-209页

作者： Elizabeth Louise Sheldon simon Charles Griffith department of Biological Sciences Macquarie UniversitySydneyNSW 2109Australia

Background: The House Sparrow(Passer domesticus) has undergone dramatic population declines in many parts of *** has been widely hypothesised that a lack of cavity nest sites has contributed to this *** the idea of the House Sparrow being nest site limited is somewhat incompatible with the long history of nest site plasticity in the ***: The nest-site selection in a population of non-native House Sparrows introduced to Australia from Europe just over 150 years ago was *** prevalence of non-cavity nesting was quantified,and nest-site selection in terms of landscape and nesting structure were ***: Flexible nesting behaviors were reported over a range of different landscapes and a surprisingly high rate of nesting in vegetation(43%) was *** nests found in vegetation were not in cavities,but were woven into the foliage and supported by branches and ***: The high rate of vegetation nesting indicates that in this introduced population,the House Sparrow is unlikely to be constrained by cavity-nest site *** high degree of nest site plasticity in the Australian population may suggest that European House Sparrows have the potential to shift away from their proclivity for cavity *** work in Europe should examine the incidence of non-cavity nesting in House Sparrows more closely,and perhaps reconsider the idea that House Sparrows are nest-site constrained.

关键词： Passer domesticus Cavity nests House Sparrow decline Nesting plasticity

Expanding plant genome-editing scope by an engineered iSpyMacCas9 system that targets A-rich PAM sequences

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Plant Communications 2021年第2期2卷 78-88页

作者： simon Sretenovic desuo Yin Adam Levav Jeremy d.Selengut Stephen M.Mount Yiping Qi department of Plant Science and Landscape Architecture University of MarylandCollege ParkMD 20742USA Hubei Academy of Agricultural Sciences Wuhan 430064China Montgomery Blair High School Silver SpringMD 20901USA Center for Bioinformatics and Computational Biology University of MarylandCollege ParkMD 20742USA department of Cell Biology and Molecular Genetics University of MarylandCollege ParkMD 20742USA Institute for Bioscience and Biotechnology Research University of MarylandRockvilleMD 20850USA

The most popular CRISPR-SpCas9 systemrecognizes canonical NGG protospacer adjacent motifs(PAMs).Previously engineered SpCas9 variants,such as Cas9-NG,favor G-rich PAMs in genome *** this manuscript,we describe a new plant genome-editing system based on a hybrid iSpyMacCas9 platform that allows for targeted mutagenesis,C to T base editing,and A to G base editing at A-rich *** study fills amajor technology gap in the CRISPR-Cas9 system for editing NAAR PAMs in plants,which greatly expands the targeting scope of ***,our vector systems are fully compatible with Gateway cloning and will work with all existing single-guide RNA expression systems,facilitating easy adoption of the systems by *** anticipate that more tools,such as prime editing,homology-directed repair,CRISPR interference,and CRISPR activation,will be further developed based on our promising iSpyMac-Cas9 platform.

关键词： plant genome editing iSpyMacCas9 PAM cytosine base editing adenine base editing

Mate-recognition and species boundaries in the ascomycetes

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Fungal diversity 2013年第1期58卷 1-12页

作者： simon H.Martin Emma T.Steenkamp Michael J.Wingfield Brenda d.Wingfield department of Genetics Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoria 0002South Africa department of Microbiology and Plant Pathology Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoria 0002South Africa

Reproductive gene evolution is commonly invoked as a source of reproductive isolation during *** possibility has not been adequately explored in the Ascomycota,the most species-rich fungal *** mechanisms of mate-recognition in this group are relatively simple:a“mating type”locus determines reproductive mode and sexual compatibility,and two pheromone/receptor pairs control sexual ***,ascomycete reproductive genes can experience unique and interesting evolutionary forces,which could lead to rapid *** this review,we examine the mechanisms of sexual interaction in ascomycetes and explore current evidence as to whether these mechanisms allow for species-specificity in *** discuss the evolutionary forces that can drive reproductive gene divergence,how these may apply in the world of ascomycetes,and their possible consequences for speciation.

关键词： Ascomycota Speciation Mating type Pheromone Receptor

Natural regeneration in logging gaps of different sizes in Subri River Forest Reserve(Ghana)

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Journal of Forestry Research 2022年第4期33卷 1157-1174页

作者： Maame Esi Hammond Radek Pokorný simon Abugre Augustine Gyedu department of Silviculture Faculty of Forestry and Wood TechnologyMendel University in BrnoZemědělská361300 BrnoCzech Republic department of Forest Science School of Natural ResourcesUniversity of Energy and Natural ResourcesP.O.Box 214SunyaniGhana Forest Services division(FSd) P.M.BKumasiGhana

Subri River Forest Reserve(SR)is the most extensive forest area in Ghana with an accompanying rich floral *** the years,logging from both legally prescribed and illegal operations remain the predominant forest disturbance in *** creation following logging is crucial in determining tree species composition and ***,the study evaluated the composition and diversity of naturally regenerated tree species in logging gaps of different sizes and,again examined the roles of these tree species in fulfilling the economic and ecological agenda of sustainable forest management after logging in *** gaps were randomly selected:4 each were grouped into small size(≤200 m^(2)),medium size(201–300 m^(2)),and large size(≥300 m^(2)).data were gathered from 1 m^(2) circular area at gap centres and repeatedly inside 1 m width strip along 20 m individual N-S-E-W *** diversity differed significantly between gap *** diversity indices were measured in large size *** sizes shared similar *** were significant differences among various height groupings of tree species across all three gap *** preferred medium to large size gaps,while shadetolerant tree species preferred small size gaps for their *** and Lower Risk Near Threatened tree species under Conservation Status and,Premium and Commercial tree species under Utilisation Status preferred small size gaps for their proliferation and ***,we recommend the single tree-based selective logging for ensuring creations of small to medium size(200–300 m^(2))gaps through adjustments to the logging permit process,revision of Allocation Quota Permit,strict adherence to the 40-year polycyclic selection system,along with more dedicated enforcement and *** along these protocols would tremendously facilitate natural regeneration of different suites of timber species resulting in the improvement of the overall biodiversity conservat

关键词： Conservation status Gap size diversity Logging Natural regeneration Subri River Forest Reserve Tree species Utilisation status

Inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes

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Insect Science 2014年第3期21卷 291-300页

作者： Jean Peccoud Joêl Bonhomme Frédérique Mahéo Manon de la Huerta Olivier Cosson Jean-Christophe simon INRA Institut de Génétique Environnement et Protection des Plantes (UMR IGEPP) Domaine de La Motte 35653 le Rheu cedex France

Herbivorous insects frequently harbor bacterial symbionts that affect their ecol- ogy and evolution. Aphids host the obligatory endosymbiont Buchnera, which is requiredfor reproduction, together with facultative symbionts whose frequencies vary across aphid populations. These maternally transmitted secondary symbionts have been particularlystudied in the pea aphid, Acyrthosiphon pisum, which harbors at least 8 distinct bacterial species （not counting Buchnera） having environmentally dependent effects on host *** particular, these symbiont species are associated with pea aphid populations feeding on specific plants. Although they are maternally inherited, these bacteria are occasionallytransferred across insect lineages. One mechanism of such nonmaternal transfer is paternal transmission to the progeny during sexual reproduction. To date, transmission of secondarysymbionts during sexual reproduction of aphids has been investigated in only a handful of aphid lineages and 3 symbiont species. To better characterize this process, we investigatedinheritance patterns of 7 symbiont species during sexual reproduction of pea aphids through a crossing experiment involving 49 clones belonging to 9 host-specialized biotypes, and117 crosses. Symbiont species in the progeny were detected with diagnostic qualitative PCR at the fundatrix stage hatching from eggs and in later parthenogenetic *** found no confirmed case of paternal transmission of symbionts to the progeny, and we observed that maternal transmission of a particular symbiont species （Serratia symbiotica）was quite inefficient. We discuss these observations in respect to the ecology of the pea aphid.

关键词： bacteria Homoptera paternal inheritance phytophagous insects symbiosis transmission failure

A simple,azulene-based colorimetric probe for the detection of nitrite in water

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Frontiers of Chemical Science and Engineering 2020年第1期14卷 90-96,F0004页

作者： Lloyd C.Murfin Carlos M.Lopez-Alled Adam C.Sedgwick Jannis Wenk Tony d.James simon E.Lewis department of Chemistry University of BathBath BA27AYUK Centre for Sustainable Chemical Technologies University of BathBath BA27AYUK department of Chemical Engineering and Water Innovation and Research Centre(WIRC@Bath) University of BathBath BA27AYUK

We describe the synthesis and evaluation of an azulene-based chemodosimeter for *** probe was found to undergo two distinct color changes upon introduction of aqueous nitrite ion.A near-instant formation of a grey color provides a qualitative indication of the presence of nitrite,followed by the formation of a deep-yellow/orange color,the endpoint from which quantitative data can be *** azulene probe exhibits 1:1 stoichiometry of reaction with nitrite in water,and is selective for nitrite over other *** azulene probe was applied to determine nitrite content in cured meat,and compared with the British Standard testing procedure(Griess test).The value obtained from the azulene-based probe agreed closely with the standard *** procedure only requires the preparation of one standard solution,instead of the three required for the standard Griess test.

关键词： azulene nitrite diazoquinone

Flow Field and Performance of Cross Flow Fans——Experimental and Theoretical Investigations

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Journal of Thermal Science 2003年第3期12卷 234-238页

作者： Martin Gabi simon dornstetter Toni Klemm Institute of Fluid Machinery University of Karlsruhe (TH) D-76128 Karlsruhe GermanyRobert Bosch GmbH D-71701 Schwieberdingen GermanyInstitute of Fluid Machinery University of Karlsruhe (TH) D-76128 Karlsruhe Germany

due to the construction and the operating principle the prediction of performance of Cross Flow Fans (CFF) is difficult and the knowledge about the internal flow regime is limited. To investigate the impact of geometrical parameters on the performance of CFF, experimental investigations, using Particle Imaging Velocimetry (PIV), and CFd calculations were carried out. Some results of PIV measurements and CFd calculations are presented, which give an impression of the internal flow and confirm the numerical calculations.

关键词： fans cross-flow fans computational fluid dynamics particle imaging velocimetry

Hepatitis B Surface Antigen and Hepatitis C Virus Antibodies among drug Users in Burkina Faso

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Advances in Microbiology 2024年第1期14卷 92-104页

作者： Sylvie Zida Kadari Cissé Odette Ky-Zerbo dinanibè Kambiré Serge Théophile Soubeiga simon Tiendrebéogo Fatou Sissoko Issa Sory Célestine Ki-Toé Solange dioma djeneba Zorom Adama Ouédraogo Cedric dimitri Axon Hien Mahamoudou Sanou Seni Kouanda Henri Gautier Ouédraogo Institut de Recherche en Sciences de la Santé Ouagadougou Burkina Faso dé partement de G&eacuteographie Universit&eacute Norbert ZONGO Koudougou Burkina Faso Secré tariat permanent du Conseil national de lutte contre le Sida et les IST (SP/CNLS-IST) Ouagadougou Burkina Faso Initiative Privé e et Communautaire pour la Sant&eacute et la Riposte au VIH/SIDA au Burkina Faso (IPC/BF) Ouagadougou Burkina Faso Unité de Formation et de Recherche en Sciences de la Sant&eacute (UFR-SDS) Universit&eacute Joseph KI-ZERBO Ouagadougou Burkina Faso

Introduction: The epidemiology of both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among drug users (dUs) is little known in West Africa. The study aimed to assess the prevalence of hepatitis B and C viruses among drug users in Burkina Faso. Methodology: This was a cross-sectional biological and behavioral survey conducted between June and August 2022, among drug users in Ouagadougou and Bobo dioulasso, the two main cities of Burkina Faso. A respondent-driven sampling (RdS) was used to recruit drug users. Hepatitis B surface antigen was determined using lateral flow rapid test kits and antibodies to hepatitis C virus in serum determined using an Enzyme-Linked Immunosorbent Assay. data were entered and analyzed using Stata 17 software. Weighted binary logistic regression was used to identify the associated factors of hepatitis B and C infections and a p-value Results: A total of 323 drug users were recruited with 97.5% males. The mean age was 32.7 years old. The inhaled or smoked mode was the most used by drug users. The adjusted hepatitis B and hepatitis C prevalence among study participants were 11.1% and 2.3% respectively. The marital status (p = 0.001), and the nationality (p = 0.011) were significantly associated with hepatitis B infection. The type of drug used was not significantly associated with hepatitis B infection or hepatitis C infection. Conclusion: The prevalence of HBsAg and anti-HCV antibodies among dUs are comparable to those reported in the general population in Burkina Faso. This result suggests that the main routes of contamination by HBV and HCV among dUs are similar to those in the population, and could be explained by the low use of the injectable route by dUs in Burkina Faso.

关键词： drug Users Hepatitis C Hepatitis B Prevalence Burkina Faso