Relevant bibliographies by topics / Species divergence

Academic literature on the topic 'Species divergence'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Species divergence"

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Bond, Jason E., David A. Beamer, Marshal C. Hedin, and Petra Sierwald. "Gradual evolution of male genitalia in a sibling species complex of millipedes (Diplopoda : Spirobolida : Rhinocricidae : Anadenobolus)." Invertebrate Systematics 17, no. 6 (2003): 711. http://dx.doi.org/10.1071/is03026.

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Jamaican millipedes in the Anadenobolus species complex provide an unusual case study of arthropods having undergone speciation in the absence of conspicuous divergence of male genitalia. Using landmark-based morphometrics, we examined shape deformation of the male anterior copulatory device in three genetically divergent yet morphologically cryptic species. A multivariate analysis of variance and relative warp analysis of nonuniform components show that although male genitalic shape is statistically different among species, many specimens are 'misplaced' in morphological space, perhaps consistent with a condition analogous to incomplete lineage sorting. A simulation of neutral nuclear gene coalescence suggests that such incomplete sorting is expected, given the depth of mtDNA divergences observed across species. The pronounced contrast between deep molecular v. incomplete genitalic divergence is at odds with the paradigm of selection-driven rapid change in male copulatory structure during arthropod speciation. Alternatively, we suggest that male genitalic divergence is evolving neutrally or in concert with other components of the genome (pleiotropy). Although we recognise the empirical validity of rapid genitalic divergence via sexual selection or sexual conflict, such models must be empirically tested using multiple lines of evidence. Accepting the rapid and divergent hypothesis without such multiple evidence scrutiny may result in a gross underestimation of evolutionary diversity and, subsequently, the misinterpretation of processes shaping genitalic change.
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Sun, Xin, Anne Bedos, and Louis Deharveng. "Unusually low genetic divergence at COI barcode locus between two species of intertidalThalassaphorura(Collembola: Onychiuridae)." PeerJ 6 (June 18, 2018): e5021. http://dx.doi.org/10.7717/peerj.5021.

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Species classification is challenging when taxa display limited morphological differences. In this paper, we combined morphology and DNA barcode data to investigate the complicated taxonomy of two Onychiurid Collembolan species.Thalassaphorura thalassophilaandThalassaphorura debilisare among the most common arthropod species in intertidal ecosystems and are often considered to be synonymous. Based on morphological and barcode analyses of fresh material collected in their type localities, we redescribed and compared the two species. However, their morphological distinctiveness was supported by a molecular divergence much smaller than previously reported at the interspecific level among Collembola. This divergence was even smaller than inter-population divergences recognized in the related edaphic speciesT. zschokkei, as well as those known between MOTUs within many Collembolan species. Our results may indicate a link between low genetic interspecific divergence and intertidal habitat, as the only biological peculiarity of the two species of interest compared to other Collembolan species analyzed to date is their strict intertidal life.
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Chantangsi, Chitchai, Denis H. Lynn, Maria T. Brandl, Jeffrey C. Cole, Neil Hetrick, and Pranvera Ikonomi. "Barcoding ciliates: a comprehensive study of 75 isolates of the genus Tetrahymena." International Journal of Systematic and Evolutionary Microbiology 57, no. 10 (October 1, 2007): 2412–23. http://dx.doi.org/10.1099/ijs.0.64865-0.

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The mitochondrial cytochrome-c oxidase subunit 1 (cox1) gene has been proposed as a DNA barcode to identify animal species. To test the applicability of the cox1 gene in identifying ciliates, 75 isolates of the genus Tetrahymena and three non-Tetrahymena ciliates that are close relatives of Tetrahymena, Colpidium campylum, Colpidium colpoda and Glaucoma chattoni, were selected. All tetrahymenines of unproblematic species could be identified to the species level using 689 bp of the cox1 sequence, with about 11 % interspecific sequence divergence. Intraspecific isolates of Tetrahymena borealis, Tetrahymena lwoffi, Tetrahymena patula and Tetrahymena thermophila could be identified by their cox1 sequences, showing <0.65 % intraspecific sequence divergence. In addition, isolates of these species were clustered together on a cox1 neighbour-joining (NJ) tree. However, strains identified as Tetrahymena pyriformis and Tetrahymena tropicalis showed high intraspecific sequence divergence values of 5.01 and 9.07 %, respectively, and did not cluster together on a cox1 NJ tree. This may indicate the presence of cryptic species. The mean interspecific sequence divergence of Tetrahymena was about 11 times greater than the mean intraspecific sequence divergence, and this increased to 58 times when all isolates of species with high intraspecific sequence divergence were excluded. This result is similar to DNA barcoding studies on animals, indicating that congeneric sequence divergences are an order of magnitude greater than conspecific sequence divergences. Our analysis also demonstrated low sequence divergences of <1.0 % between some isolates of T. pyriformis and Tetrahymena setosa on the one hand and some isolates of Tetrahymena furgasoni and T. lwoffi on the other, suggesting that the latter species in each pair is a junior synonym of the former. Overall, our study demonstrates the feasibility of using the mitochondrial cox1 gene as a taxonomic marker for ‘barcoding’ and identifying Tetrahymena species and some other ciliated protists.
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Head, Megan L., Emily A. Price, and Janette W. Boughman. "Body size differences do not arise from divergent mate preferences in a species pair of threespine stickleback." Biology Letters 5, no. 4 (May 27, 2009): 517–20. http://dx.doi.org/10.1098/rsbl.2009.0216.

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Ecological speciation can be driven by divergent natural and/or sexual selection. The relative contribution of these processes to species divergence, however, is unknown. Here, we investigate how sexual selection in the form of male and female mate preferences contributes to divergence of body size. This trait is known be under divergent natural selection and also contributes to sexual isolation in species pairs of threespine sticklebacks ( Gasterosteus aculeatus ). We show that neither female nor male size preferences contribute to body size divergence in this species pair, suggesting that size-based sexual isolation arises primarily through natural selection.
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Oneal, Elen, and L. Lacey Knowles. "Ecological selection as the cause and sexual differentiation as the consequence of species divergence?" Proceedings of the Royal Society B: Biological Sciences 280, no. 1750 (January 7, 2013): 20122236. http://dx.doi.org/10.1098/rspb.2012.2236.

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Key conceptual issues about speciation go unanswered without consideration of non-mutually exclusive factors. With tests based on speciation theory, we exploit the island distribution and habitat differences exhibited by the Caribbean cricket Amphiacusta sanctaecrucis , and with an analysis of divergent ecological selection, sexually selected differentiation and geographical isolation, address how these different factors interact. After testing for divergent selection by comparing neutral genetic and morphological divergence in one ecological (mandible shape) and one sexual (male genitalia shape) trait, we examine whether ecological or sexual selection is the primary mechanism driving population divergence. We find that all three factors—isolation, ecological and sexual selection—contribute to divergence, and that their interaction determines the stage of completeness achieved during the speciation process, as measured by patterns of genetic differentiation. Moreover, despite the striking diversity in genitalic shapes across the genus Amphiacusta , which suggests that sexual selection drives speciation, the significant differences in genitalia shape between forest habitats revealed here implies that ecological divergence may be the primary axis of divergence. Our work highlights critical unstudied aspects in speciation—differentiating the cause from the consequence of divergence—and suggests avenues for further disentangling the roles of natural and sexual selection in driving divergence in Amphiacusta .
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Ma, Tao, Kun Wang, Quanjun Hu, Zhenxiang Xi, Dongshi Wan, Qian Wang, Jianju Feng, et al. "Ancient polymorphisms and divergence hitchhiking contribute to genomic islands of divergence within a poplar species complex." Proceedings of the National Academy of Sciences 115, no. 2 (December 26, 2017): E236—E243. http://dx.doi.org/10.1073/pnas.1713288114.

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How genome divergence eventually leads to speciation is a topic of prime evolutionary interest. Genomic islands of elevated divergence are frequently reported between diverging lineages, and their size is expected to increase with time and gene flow under the speciation-with-gene-flow model. However, such islands can also result from divergent sorting of ancient polymorphisms, recent ecological selection regardless of gene flow, and/or recurrent background selection and selective sweeps in low-recombination regions. It is challenging to disentangle these nonexclusive alternatives, but here we attempt to do this in an analysis of what drove genomic divergence between four lineages comprising a species complex of desert poplar trees. Within this complex we found that two morphologically delimited species, Populus euphratica and Populus pruinosa, were paraphyletic while the four lineages exhibited contrasting levels of gene flow and divergence times, providing a good system for testing hypotheses on the origin of divergence islands. We show that the size and number of genomic islands that distinguish lineages are not associated with either rate of recent gene flow or time of divergence. Instead, they are most likely derived from divergent sorting of ancient polymorphisms and divergence hitchhiking. We found that highly diverged genes under lineage-specific selection and putatively involved in ecological and morphological divergence occur both within and outside these islands. Our results highlight the need to incorporate demography, absolute divergence measurement, and gene flow rate to explain the formation of genomic islands and to identify potential genomic regions involved in speciation.
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Hou, Zhong-e., Zhu Li, and Shu-qiang Li. "Identifying Chinese species of Gammarus (Crustacea: Amphipoda) using DNA barcoding." Current Zoology 55, no. 2 (April 1, 2009): 158–64. http://dx.doi.org/10.1093/czoolo/55.2.158.

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Abstract Using a standard cytochrome c oxidase I sequence, DNA barcoding has been shown to be effective to distinguish known species and to discover cryptic species. Here we assessed the efficiency of DNA barcoding for the amphipod genus Gammarus from China. The maximum intraspecific divergence for widespread species, Gammarus lacustris, was 3.5%, and mean interspecific divergence reached 21. 9%. We presented a conservative benchmark for determining provisional species using maximum intraspecific divergence of Gammarus lacustris. Thirty-one species possessed distinct barcode clusters. Two species were comprised of highly divergent clades with strong neighbor-joining bootstrap values, and likely indicated the presence of cryptic species. Although DNA barcoding is effective, future identification of species of Gammarus should incorporate DNA barcoding and morphological detection.
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Assis, G. M. L., R. F. Euclydes, C. D. Cruz, and C. B. Valle. "Genetic divergence in Brachiaria species." Cropp Breeding and Applied Biotechnology 2, no. 3 (September 30, 2002): 331–38. http://dx.doi.org/10.12702/1984-7033.v02n03a02.

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Fahrenkamp-Uppenbrink, J. "Ancient patterns reveal species divergence." Science 345, no. 6196 (July 31, 2014): 526–28. http://dx.doi.org/10.1126/science.345.6196.526-p.

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Livshits, M. A., and M. V. Volkenstein. "On the divergence of species." Biosystems 24, no. 4 (January 1991): 301–3. http://dx.doi.org/10.1016/0303-2647(91)90048-p.

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Dissertations / Theses on the topic "Species divergence"

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Madsen, Susan M. "Divergence in repetitive DNA sequences among three sitopsis wheat species /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9901260.

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Colbeck, Gabriel Joseph. "Phylogeography, song divergence and reproductive isolation in two species of songbird." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Dissertations/Spring2009/g_colbeck_042009.pdf.

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Henry, Amanda Ann (Shaffer). "Clarkia genetic basis of sister species divergence Clarkia concinna x Clarkia breweri /." Thesis, Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/henry/HenryA0806.pdf.

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Ross, Rebecca Isabel Charlotte. "Local adaptation and adaptive divergence in a hybrid species complex in Senecio." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543007.

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FitzGerald, Alyssa. "Speciation and Ecological Niche Divergence of a Boreal Forest Bird Species Complex." Thesis, State University of New York at Albany, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10276556.

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Evolutionary biologists are supremely interested in the events that cause populations to diverge and speciate, and the mechanisms that maintain divergence over time. Here, I investigate the evolutionary history of a boreal bird species complex. Boreal bird species are co-distributed, diverged during the Pleistocene, and generally have patterns of genetic divergence that are consistent with a single “boreal” clade in northern and eastern North America. The Gray-cheeked Thrush species complex, however, shows a possible species break in eastern North America between the Bicknell’s Thrush ( Catharus bicknelli) and Gray-cheeked Thrush (Catharus minimus ). Using population genetic and genomic analyses of the largest sampling to-date of either species, I find that the eastern break indeed coincides with a species-level divergence, although low levels of admixture in a few individuals and one probable hybrid hint at the possibility of occasional hybridization. Species distribution models (SDMs) of the Last Glacial Maximum revealed that divergence may have been maintained by residence in different late-Pleistocene refugia. However, because speciation occurred mid-Pleistocene, I examined the geographical context of divergence of the Bicknell’s Thrush and Gray-cheeked Thrush using multivariate analyses and ecological niche modeling techniques of local-scale habitat data and broad-scale climate and tree species distributions. Local-scale habitat analyses reveal that the thrushes breed at sites with unique tree species composition, physiognomy (forest structure), and ground cover characteristics; furthermore broad-scale analyses reveal that niche divergence, rather than conservatism, was the predominant pattern for these species, suggesting that ecological divergence has played a role in their speciation. This dissertation supports the hypothesis that the Bicknell’s Thrush and Gray-cheeked Thrush are distinctive species that breed in divergent local- and broad-scale niches and emphasizes that this species-level divergence seems unique among boreal bird species.

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Herrig, Danielle Kay. "Evaluating gene flow, gene expression divergence, and hybrid expression in Drosophila sister species." Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/2222.

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A primary goal of evolutionary biology is to elucidate the factors necessary for a single interbreeding species to become two independent species. Observations and data collected and recorded since the 6th century B.C. have added to our comprehension of the “the origin of species—that mystery of mysteries” (DARWIN 1859). To continue to add to our knowledge of how speciation occurs and how species interact, it is crucial to determine 1) how different categories of genes evolve as species diverge, 2) what happens to hybrids of two species, and 3) if genetic exchange is allowed between species, where it is located. In the first research aim of my dissertation, I look for population genetic trends and signatures of gene flow in a minimally studied set of Drosophila sister species using sequences of 26 nuclear and mitochondrial regions in 29 isofemale lines of D. subobscura and D. madierensis. Standard population genetic tests revealed that the X chromosome evolves faster than the autosomes in these species. We also find evidence of genetic exchange for some autosomal genes while both the sex chromosomes and mitochondrial genomes remain distinct between species. In the second research aim of my dissertation, I assess the rates of gene expression evolution for sex-biased genes located on the X chromosome and autosomes. We find that gene expression evolves faster in males than females and find evidence of faster-X evolution that is exclusive to genes expressed at higher levels in males. The X chromosome has previously been shown to have a disproportionately large influence on hybrid male sterility compared to autosomes. I investigate this trend and find that the sex chromosomes have a large influence on autosomal expression levels in hybrid males and hybrid females. Specifically, uniparental inheritance of the X chromosome results in greater differences between reciprocal hybrids and higher levels of hybrid misexpression.
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Oyakawa, Chisako. "Species-specific Acoustic Structures Organizing Population Divergence and Acoustic Individuality in Wild Agile Gibbons." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/124359.

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Mercader, Rodrigo J. "Species ranges, host selection, and hybridization how increased hybridization is leading to host use divergence in a polyphagous sibling species pair /." Diss., Connect to online resource - MSU authorized users, 2008.

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Thesis (Ph.D.)--Michigan State University. Dept. of Entomology and Program in Ecology, Evolutionary Biology, and Behavior, 2008.
Title from PDF t.p. (viewed on July 17, 2009) Includes bibliographical references (p. 115-126). Also issued in print.
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Zhou, Y. (Yongfeng). "Demographic history and climatic adaptation in ecological divergence between two closely related parapatric pine species." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526206769.

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Abstract Both demographic histories and natural selection complicate the speciation process. There is a need to jointly study the effects of natural selection on so called magic traits that can cause reproductive isolation such as climatic adaptation, and its interaction with neutral demographic histories. Closely related incipient coniferous species offer us a great system for this effort. I used genetic variation at one set of climate-related candidate genes and another set of reference loci and cytoplasmic genomic fragments of two closely related parapatric pine species: Pinus massoniana Lamb. and Pinus hwangshanensis Hisa. Population genetic analyses were used to measure genetic variation and detect signals of ancient and recent selection. Speciation parameters including migration rates and divergence times at candidate genes and reference loci were compared under the Isolation with migration model. Hierarchical Approximate Bayesian Computation (ABC) was used to define demographic and speciation models. Intra- and interspecific genetic variation at cytoplasmic and nuclear intronic sequences were compared between parapatric populations and allopatric populations to distinguish the effects of introgression and incomplete lineage sorting in generating shared genetic variation between the species. The results showed that ancient selection were shared by the lineages leading to the species while recent selection has been species-specific. Candidate genes had significant lower migration rates compared to reference loci. Recent differential climatic selection might counteract against gene flow at underlying genes, which therefore favors divergence between the two pines through ecological speciation. Shared mitotypes were randomly distributed across species’ ranges, which therefore supported the incomplete lineage sorting hypothesis, but the shared nuclear intronic variation distributed more frequently in parapatric populations than in allopatric populations, supported the introgression hypothesis. ABC and species’ distribution modeling also supported the secondary gene flow model. The three genomes had different rates of mutation and gene flow might mirror different phases of the speciation continuum. The results in this thesis are valuable for understanding evolution in general and for other applied purposes such as tree breeding and climate change adaptation
Tiivistelmä Luonnonvalinta ja populaatioiden historian demografia tekevät lajiutumisesta monimutkaisen tapahtumaketjun. Luonnonvalinnan ja demografisten tekijöiden vuorovaikutusta on paras tutkia samanaikaisesti, kun tarkastellaan lajiutumiseen vaikuttavia ominaisuuksia. Tällaisia ovat esimerkiksi ilmastoon sopeutumiseen liittyvät ominaisuudet. Lähisukuiset havupuulajit tarjoavat erinomaiset mahdollisuudet tähän työhön. Tutkin geneettistä muuntelua yhtäältä ilmastosopeutumiseen liittyvissä ns. ehdokasgeeneissä ja toisaalta neutraaleiksi oletetuissa verrokkigeeneissä sekä sytoplasman genomeissa kahdessa lähisukuisessa mäntylajissa Pinus massoniana Lamb. ja Pinus hwangshanensis Hisa, joiden populaatiot esiintyvät joskus erillään toisistaan (allopatrisesti), toisinaan vierekkäin (parapatrisesti). Mittasin muuntelun määrää ja etsin merkkejä valinnan vaikutuksesta. Vertasin erilaisia lajiutumismallien parametrejä verrokki- ja ehdokasgeeneissä. Käytin simulaatioita etsiäkseni parhaat demografiset ja lajiutumiseen liittyvät mallit. Vertasin kloroplastien ja mitokondrioiden genomien sekvenssien lajinsisäistä ja lajien välistä muuntelua allopatrisissa ja parapatrisissa populaatioissa tutkiakseni onko lajien yhteinen muuntelu seurausta siitä että lajien eriytymisestä on kulunut vain vähän aikaa vai siitä että sen jälkeen on tapahtunut geenivirtaa. Kauan sitten tapahtunut valinta on vaikuttanut samalla tavalla kumpaankin lajiin, osin koska tutkimus kohdistui myös niiden yhteiseen edeltäjälinjaan. Äskettäinen valinta taas oli suuremmassa määrin kummallekin lajille ominaista. Viime aikojen ilmastoon liittyvä valinta on voinut vähentää geenivirtaa ehdokasgeeneissä, mikä voisi edistää ekologista lajiutumista. Tuman DNA:n muuntelu jakautuminen tuki sitä mahdollisuutta että lajien yhteinen geneettinen muuntelu johtuu äskettäisestä geenivirrasta, ei vain siitä että lajiutuminen on niin varhaisessa vaiheessa. Mitokondrioiden geeneissä lajeilla yhtä paljon yhteistä muuntelua sekä allopatrisissa että parapatrisissa populaatioissa, mikä tukee sen sijaan eriytymisen jälkeistä epätäydellistä muuntelun erilaistumista. Eri genomit heijastavat lajiutumisprosessin eri vaiheita. Väitöskirjan tulokset ovat osaltaan tuottaneet uutta tietoa lajiutumisesta ja valinnasta. Lisäksi niillä on merkitystä ilmastomuutoksen vaikutusten ymmärtämisessä ja metsänjalostuksessa
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Wyatt, Kimberly M. "Rapid morphological divergence among subpopulations of the introduced common wall lizard, Podarcis muralis." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1377874890.

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Books on the topic "Species divergence"

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Mattson, Carol. Misfits in school: Creative divergent children. Saratoga, Calif: R&E Publishers, 1985.

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Hong, Yunsook. A sociolinguistic study of Seoul Korean: With a special section on language divergence between Northand South Korea. Seoul, Korea: Research Center for Peace and Unification of Korea, 1991.

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Hong, Yunsook. A sociolinguistic study of Seoul Korean: With a special section on language divergence between North and South Korea. Seoul, Korea: Research Center for Peace and Unification of Korea, 1991.

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Blaha, Stephen. The origin of the standard model: The genesis of four quark and lepton species, parity violation, the electro weak sector, color SU(3), three visible generations of fermions, and one generation of dark matter with dark energy ; Quantum theory of the third kind : a new type of divergence-free quantum field theory supporting a unified standard model of elementary particles and quantum gravity based on a new method in the calculus of variations. Auburn, NH: Pingree-Hill Publishing, 2006.

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O, Hope Richard, ed. Educating a new majority: Transforming America's educational system for diversity. San Francisco: Jossey-Bass Publishers, 1996.

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Saff, E. B., Douglas Patten Hardin, Brian Z. Simanek, and D. S. Lubinsky. Modern trends in constructive function theory: Conference in honor of Ed Saff's 70th birthday : constructive functions 2014, May 26-30, 2014, Vanderbilt University, Nashville, Tennessee. Providence, Rhode Island: American Mathematical Society, 2016.

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Ontario Educational Research Council. Conference. [Papers presented at the 33rd Annual Conference of the Ontario Educational Research Council, Toronto, Ontario, December 6-7, 1991]. [Ontario: s.n.], 1991.

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Ontario Educational Research Council. Conference. [Papers presented at the 28th Annual Conference of the Ontario Educational Research Council, Toronto, Ontario, Dec. 1986]. [Toronto, ON: s.n.]., 1986.

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Conference, Ontario Educational Research Council. [Papers presented at the 30th Annual Conference of the Ontario Educational Research Council, Toronto, Ontario, December 2-3, 1988]. [Toronto, ON: s.n.], 1988.

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Ontario Educational Research Council. Conference. [Papers presented at the 34th Annual Conference of the Ontario Educational Research Council, Toronto, Ontario, December 4 - 5, 1992]. [Ontario: s.n.], 1992.

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Book chapters on the topic "Species divergence"

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Jauhar, Prem P. "Karyotypes and Species Evolution and Divergence." In Monographs on Theoretical and Applied Genetics, 29–41. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-84086-9_3.

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Hreggvidsson, Gudmundur Oli, Solveig K. Petursdottir, Sigmar K. Stefansson, Snaedis H. Björnsdottir, and Olafur H. Fridjonsson. "Divergence of Species in the Geothermal Environment." In Adaption of Microbial Life to Environmental Extremes, 41–74. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-48327-6_3.

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Ortíz-Barrientos, Daniel, Jane Reiland, Jody Hey, and Mohamed A. F. Noor. "Recombination and the divergence of hybridizing species." In Contemporary Issues in Genetics and Evolution, 167–78. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-010-0265-3_2.

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Singh, R. S. "Patterns of Species Divergence and Genetic Theories of Speciation." In Population Biology, 231–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-74474-7_8.

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Cohan, Frederick M. "Genomes reveal the cohesiveness of bacterial species taxa and provide a path towards describing all of bacterial diversity." In Trends in the systematics of bacteria and fungi, 282–300. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244984.0282.

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Abstract This book chapter argues that bacterial systematists of the mid-20th century fortuitously created a species-level systematics that actually fits an important universal theory of speciation by discussing taxonomy would allow us to infer the important characteristics of any unknown organism once we classify it to species. It turns out, unexpectedly, that bacterial species taxa share a species-like property with the species taxa of zoology and botany. While recombination within species taxa of all these groups fails to prevent diversification within species, recombination nevertheless appears to act universally as a force of cohesion within species taxa. That is, recurrent recombination within species limits neutral sequence divergence within species taxa of plants, animals, and bacteria; recombination also allows a sharing of generally adaptive genes across a species range. The 95% ANI criterion that demarcates the traditionally defined species taxa of bacteria fortuitously also yields groups of bacteria that are subject to the species-like property of cohesion, where recombination prevents neutral sequence divergence among ecotypes within a species. Use of the ANI criterion, then, not only provides an easily used algorithm for demarcating bacterial species; it also places bacterial demarcation on the same theory-based foundation as the species taxonomy of animals and plants.
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Eanes, Walter F. "Patterns of Polymorphism and Between Species Divergence in the Enzymes of Central Metabolism." In Non-Neutral Evolution, 18–28. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4615-2383-3_2.

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Zhang, Shilu, Sara Knaack, and Sushmita Roy. "Enabling Studies of Genome-Scale Regulatory Network Evolution in Large Phylogenies with MRTLE." In Methods in Molecular Biology, 439–55. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2257-5_24.

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AbstractTranscriptional regulatory networks specify context-specific patterns of genes and play a central role in how species evolve and adapt. Inferring genome-scale regulatory networks in non-model species is the first step for examining patterns of conservation and divergence of regulatory networks. Transcriptomic data obtained under varying environmental stimuli in multiple species are becoming increasingly available, which can be used to infer regulatory networks. However, inference and analysis of multiple gene regulatory networks in a phylogenetic setting remains challenging. We developed an algorithm, Multi-species Regulatory neTwork LEarning (MRTLE), to facilitate such studies of regulatory network evolution. MRTLE is a probabilistic graphical model-based algorithm that uses phylogenetic structure, transcriptomic data for multiple species, and sequence-specific motifs in each species to simultaneously infer genome-scale regulatory networks across multiple species. We applied MRTLE to study regulatory network evolution across six ascomycete yeasts using transcriptomic measurements collected across different stress conditions. MRTLE networks recapitulated experimentally derived interactions in the model organism S. cerevisiae as well as non-model species, and it was more beneficial for network inference than methods that do not use phylogenetic information. We examined the regulatory networks across species and found that regulators associated with significant expression and network changes are involved in stress-related processes. MTRLE and its associated downstream analysis provide a scalable and principled framework to examine evolutionary dynamics of transcriptional regulatory networks across multiple species in a large phylogeny.
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Amaral, Danilo T., Monique Romeiro-Brito, and Isabel A. S. Bonatelli. "Exploring Phylogenetic Relationships and Divergence Times of Bioluminescent Species Using Genomic and Transcriptomic Data." In Bioluminescence, 409–23. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2473-9_32.

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Matzke, Nicholas J. "Science Without Species: Doing Science with Tree-Thinking." In Speciesism in Biology and Culture, 47–61. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99031-2_3.

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AbstractThe focus of this volume is speciesism. While the concepts of species and speciation remain the focus of a great deal of research, it is worth exploring how in recent decades evolutionary biology has, in several ways, moved away from species as the key unit of analysis of biological questions. I begin by outlining how phylogenetic comparative methods have become essential methodological tools in statistical analyses of relationships between traits. Species are not statistically independent observations, because the reality is that they are related, genetically and statistically, on a phylogenetic tree. Phylogeny also plays a key role in modern analyses of spatial patterns in biodiversity, and in fact relying on phylogenetic biodiversity measures can avoid a number of problems created by attempting to impose a uniform species rank across different continents and clades. Similarly, a major challenge in modern studies of diversification and extinction concerns the units of analysis and how they are defined and recognized. Both “genus” and “species” are human-defined ranks imposed on the phylogenetic tree. The phylogenetic tree is the more fundamental reality that is produced by the macroevolutionary process, and it could include every level of gradation of genetic and morphological divergence. Once ranks are imposed upon it, a variety of methodological problems are created as scientists attempt to make these ranks standardized and comparable across different datasets and timescales. I outline how phylogenetic thinking might help provide a solution. I conclude with other examples where cutting-edge science is done with phylogenies without much need of the “species” rank—for example, in the battle against Covid-19.
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Goto, Akira, and Tadashi Andoh. "Genetic divergence between the sibling species of river-sculpin, Cottus amblystomopsis and C. nozawae, with special reference to speciation." In Alternative life-history styles of fishes, 257–66. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-2065-1_15.

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Conference papers on the topic "Species divergence"

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Liao, Yi-Chang. "Acoustic divergence of closely related psylloid species (Hemiptera: Psylloidea)." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.107872.

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Galitskii, V. V. "On the morphological source of divergence of (coniferous) tree species. Model analysis." In Mathematical Biology and Bioinformatics. Pushchino: IMPB RAS - Branch of KIAM RAS, 2018. http://dx.doi.org/10.17537/icmbb18.44.

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Hakim, Ammar, and John Loverich. "Nautilus: Robust, positivity and divergence preserving code for multi-fluid, multi-species electromagnetics and plasma physics applications." In 42nd AIAA Plasmadynamics and Lasers Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2011. http://dx.doi.org/10.2514/6.2011-4011.

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Protopopova, M. V., V. V. Pavlichenko, and V. V. Chepinoga. "GENETIC DIVERGENCE OF RELICT PLANT SPECIES POPULATIONS IN BAIKAL SIBERIA AS A RESULT OF GLOBAL CLIMATE CHANGE." In The All-Russian Scientific Conference with International Participation and Schools of Young Scientists "Mechanisms of resistance of plants and microorganisms to unfavorable environmental". SIPPB SB RAS, 2018. http://dx.doi.org/10.31255/978-5-94797-319-8-983-985.

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Saher, Noor Us. "Molecular Confirmation and Evolutionary Divergence Between Two Species of the Genus Petrolisthes Porcellanid Crabs from the Coastal Waters of Pakistan." In IBRAS 2021 INTERNATIONAL CONFERENCE ON BIOLOGICAL RESEARCH AND APPLIED SCIENCE. Juw, 2021. http://dx.doi.org/10.37962/ibras/2021/125-126.

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"Genome composition and divergence between Russian boreal species in the genus Elymus (Poaceae), as assessed by nuclear gene GBSS1 sequencing." In Plant Genetics, Genomics, Bioinformatics, and Biotechnology. Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 2019. http://dx.doi.org/10.18699/plantgen2019-007.

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Brasoveanu, Dan, and Ashwani K. Gupta. "A Mathematical Model for Predicting Conditions That Prevent Gaseous Fuel-Air Mixing." In ASME 2000 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/detc2000/cie-14683.

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Abstract A unified model is used here to determine the distributions of pressure, temperature and velocity that reduce gaseous fuel-air mixing. The model uses the fuel mass fraction within infinitesimal fluid elements and the total derivative of this fraction with respect to time to quantify the degree and rate of mixing, respectively. An Eulerian representation is used. The model is valid for gaseous fuels that contain a single chemical species and for low-pressure combustors. The model permits the presence of only trace amounts of combustion products within the mixing region. Aside from these restrictions, the mixing model can be applied to a variety of combustor designs and operational conditions. Results show that certain distributions of pressure, temperature and velocity at the fuel-air boundary reduce or even prevent gaseous fuel-air mixing, in particular whenever the logarithmic rate of temperature and the velocity divergence are comparable. These conditions yield low intensity and efficiency combustion as well as high pollutants emission level.
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Urbaniak, Monika, Agnieszka Waśkiewicz, Grzegorz Koczyk, Lidia Błaszczyk, Silvio Uhlig, and Łukasz Stępień. "Naturally-produced beauvericins and divergence of <em>BEAS</em> gene among <em>Fusarium</em> and <em>Trichoderma</em> species." In 1st International Electronic Conference on Toxins. Basel, Switzerland: MDPI, 2021. http://dx.doi.org/10.3390/iect2021-09145.

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Hu, Jian, Xiangyu Chi, Naihua Wang, and Qian Su. "Numerical Study of the Gas-Liquid Mass Transfer in the Volume Control Tank." In 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-92053.

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Abstract In this paper, a novel numerical model is established to conduct transient simulations of gas-liquid mass transfer in volume control tank (VCT). The surface divergence model was coupled with the CFD model to model the gas-liquid mass transfer near the interface. And the species transport model was used to model the homogeneous mass transfer inside the liquid. The simulated data is verified by experimental results. And the deviation between simulation results and experimental results is less than 6.67%. This model can accurately predict the gas-liquid mass transfer in VCT. Moreover, the flow field and concentration field in the VCT were analyzed. And the results show that there are three dominant mechanisms of gas-liquid mass transfer in VCT. The first mechanism is the entrainment of high-concentration fluids by surface jets at the gas-liquid interface. And the second is a double vortex structure above the jet inlet to pump the high-nitrogen-concentration fluid to a low-nitrogen-concentration area. The third is the mass exchange between the vortex at the end of the jet and the jet. Furthermore, the effects of thermal parameters (the temperature, operating pressure and inflow flow rate) on the VCT interface mass transfer process were also studied.
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Lait, Jeff. "Divergence projection with electrostatics." In SIGGRAPH '18: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2018. http://dx.doi.org/10.1145/3214745.3214752.

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Reports on the topic "Species divergence"

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Kugel, H. W., G. M. Gammel, L. R. Grisham, R. Kaita, J. H. Kamperschroer, R. A. Langley, C. W. Magee, et al. Measurements of neutral beam species, impurities, spatial divergence, energy dispersion, pressure, and reionization for the TFTR (Tokamak Fusion Test Reactor) US Common Long Pulse Ion Source. Office of Scientific and Technical Information (OSTI), June 1988. http://dx.doi.org/10.2172/7155086.

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David, Lior, Yaniv Palti, Moshe Kotler, Gideon Hulata, and Eric M. Hallerman. Genetic Basis of Cyprinid Herpes Virus-3 Resistance in Common Carp. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7592645.bard.

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The goal of this project was to provide scientific and technical basis for initiating the development of breeding protocols using marker assisted selection for viral disease resistance in common carp. The specific objectives were: 1) Establishing families and characterizing the phenotypic and genetic variation of viral resistance; 2) Measuring the dynamics of immune response and developing a method to measure the long term immune memory; 3) Developing markers and generating a new genetic linkage map, which will enable initial QTL mapping; and, 4) Identifying genetic linkage of markers and candidate genes (like MHC and TLRs) with resistance to CyHV-3. The common carp is an important farmed freshwater fish species in the world. Edible carp is second only to tilapia in Israeli aquaculture production and ornamental carp (koi) is an important product in both the US and Israel. Carp industries worldwide have recently suffered enormous economic damage due to a viral disease caused by Cyprinid herpes virus 3 (CyHV-3). Aside from preventative measures, a sustainable solution to this problem will be to establish a genetic improvement program of the resistance of fish to the pathogen. The aims of the project was to take the necessary first steps towards that. The differences in survival rates after infection with CyHV-3 virus among 20 families from six types of crosses between three carp lines (two commercial lines and one wild-type carp) revealed that the wild-type carp and its crosses had a much-improved survival over the crosses of the commercial lines themselves. These crosses set the starting point for breeding of commercial strains with improved resistance. Resistant fish had lower antibody titer against the virus suggesting that resistance might depend more on the innate immunity. A set of 500 microsateliite markers was developed and the markers are currently being used for generating a genetic linkage map for carp and for identifying disease resistance QTL. Fourteen candidate immune genes, some of which were duplicated, were cloned from the carp and SNP markers were identified in them. The expression of these genes varied between tissues and suggested functional divergence of some duplicated genes. Initial association between CyHV-3 resistance and one of the genes was found when SNP alleles in these genes were tested for their segregation between susceptible and resistant progeny. The results of this project have implications to the development of viral resistant commercial carp strains and effective immunization against this aggressive disease. The genetic and immunological knowledge accumulated in this project will not only promote carp and koi production but will also contribute to a broader understanding of fish immunogenetics.
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Yogev, David, Ricardo Rosenbusch, Sharon Levisohn, and Eitan Rapoport. Molecular Pathogenesis of Mycoplasma bovis and Mycoplasma agalactiae and its Application in Diagnosis and Control. United States Department of Agriculture, April 2000. http://dx.doi.org/10.32747/2000.7573073.bard.

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Mycoplasma bovis and M. agalactiae are two phylogenetically related mycoplasmas which cause economically significant diseases in their respective bovine or small ruminant hosts. These organisms cause persistent asymptomatic infections that can result in severe outbreaks upon introduction of carrier animals into susceptible herds. Little is known about the mechanisms underlying mycoplasma-host interaction, variation in virulence, or of the factors enabling avoidance of the host immune system. In recent years it has become apparent that the ability of pathogenic microorganisms to rapidly alter surface antigenic structures and to fine tune their antigenicity, a phenomena called antigenic variation, is one of the most effective strategies used to escape immune destruction and to establish chronic infections. Our discovery of a novel genetic system, mediating antigenic variation in M. bovis (vsp) as well as in M. agalactiae (avg) served as a starting point for our proposal which included the following objectives: (i) Molecular and functional characterization of the variable surface lipoproteins (Vsp) system of M. bovis and comparison with the Vsp-counterpart in M. agalactiae (ii) Determination of the role of Vsp proteins in the survival of M. bovis when confronted by host defense factors, (iii) Assessment of Vsp-based genetic and antigenic typing of M. bovis and M. agalactiae for epidemiology of infection and (iv) Improvement of diagnostic tests for M. bovis and M. agalactiae based on the vsp-and vsp-analogous systems. We have carried out an extensive molecular characterization of the vsp system and unravelled the precise molecular mechanism responsible for the generation of surface antigenic variation in M. bovis. Our data clearly demonstrated that the two pathogenic mycoplasma species possess large gene families encoding variable lipoprotein antigens that apparently play an important role in immune evasion and in pathogen-host interaction during infection. Phase variable production of these antigens was found to be mediated by a novel molecular mechanism utilizing double site-specific DNA inversions via an intermediate vsp configuration. Studies in model systems indicate that phase variation of VspA is relevant in interaction between M. bovis and macrophages or monocytes, a crucial stage in pathogenesis. Using an ELISA test with captured VspA as an antigen, phase variation was shown to occur in vivo and under field conditions. Genomic rearrangements in the avg gene family of M. agalactiae were shown to occur in vivo and may well have a role in evasion of host defences and establishment of chronic infection. An epidemiological study indicated that patterns of vsp-related antigenic variation diverge rapidly in an M. bovis infected herd. Marked divergence was also found with avg-based genomic typing of M. agalactiae in chronically infected sheep. However, avg-genomic fingerprints were found to be relatively homogeneous in different animals during acute stages of an outbreak of Contagious Agalactiae, and differ between unrelated outbreaks. These data support the concept of vsp-based genomic typing but indicate the necessity for further refinement of the methodology. The molecular knowledge on these surface antigens and their encoding genes provides the basis for generating specific recombinant tools and serological methods for serodiagnosis and epidemiological purposes. Utilization of these methods in the field may allow differentiating acutely infected herds from chronic herds and disease-free herds. In addition the highly immunogenic nature of these lipoproteins may facilitate the design of protective vaccine against mycoplasma infections.
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Friedman, Haya, Julia Vrebalov, and James Giovannoni. Elucidating the ripening signaling pathway in banana for improved fruit quality, shelf-life and food security. United States Department of Agriculture, October 2014. http://dx.doi.org/10.32747/2014.7594401.bard.

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Background : Banana being a monocot and having distinct peel and pulp tissues is unique among the fleshy fruits and hence can provide a more comprehensive understanding of fruit ripening. Our previous research which translated ripening discoveries from tomato, led to the identification of six banana fruit-associated MADS-box genes, and we confirmed the positive role of MaMADS1/2 in banana ripening. The overall goal was to further elucidate the banana ripening signaling pathway as mediated by MADS-boxtranscriptional regulators. Specific objectives were: 1) characterize transcriptional profiles and quality of MaMADS1/2 repressed fruit; 2) reveal the role of additional MaMADSgenes in ripening; 3) develop a model of fruit MaMADS-box mode of action; and 4) isolate new components of the banana ripening signaling pathway. Major conclusion: The functions of the banana MaMADS1-5 have been examined by complimenting the rinor the TAGL1-suppressed lines of tomato. Only MaMADS5 exhibited partial complementation of TAGL1-suppressed and rinlines, suggesting that while similar genes play corresponding roles in ripening, evolutionary divergence makes heterologous complementation studies challenging. Nevertheless, the partial complementation of tomato TAGL1-surpessed and rinlines with MaMADS5 suggests this gene is likely an important ripening regulator in banana, worthy of further study. RNA-seqtranscriptome analysis during ripening was performed on WT and MaMADS2-suppressed lines revealing additional candidate genes contributing to ripening control mechanisms. In summary, we discovered 39 MaMADS-box genes in addition to homologues of CNR, NOR and HB-1 expressed in banana fruits, and which were shown in tomato to play necessary roles in ripening. For most of these genes the expression in peel and pulp was similar. However, a number of key genes were differentially expressed between these tissues indicating that the regulatory components which are active in peel and pulp include both common and tissue-specific regulatory systems, a distinction as compared to the more uniform tomato fruit pericarp. Because plant hormones are well documented to affect fruit ripening, the expressions of genes within the auxin, gibberellin, abscisic acid, jasmonic acid, salicylic and ethylene signal transduction and synthesis pathways were targeted in our transcriptome analysis. Genes’ expression associated with these pathways generally declined during normal ripening in both peel and pulp, excluding cytokinin and ethylene, and this decline was delayed in MaMADS2-suppressed banana lines. Hence, we suggest that normal MaMADS2 activity promotes the observed downward expression within these non-ethylene pathways (especially in the pulp), thus enabling ripening progression. In contrast, the expressions of ACSand ACOof the ethylene biosynthesis pathway increase in peel and pulp during ripening and are delayed/inhibited in the transgenic bananas, explaining the reduced ethylene production of MaMADS2-suppressed lines. Inferred by the different genes’ expression in peel and pulp of the gibberellins, salicylic acid and cytokinins pathways, it is suggested that hormonal regulation in these tissues is diverse. These results provide important insights into possible avenues of ripening control in the diverse fruit tissues of banana which was not previously revealed in other ripening systems. As such, our transcriptome analysis of WT and ripening delayed banana mutants provides a starting point for further characterization of ripening. In this study we also developed novel evidence that the cytoskeleton may have a positive role in ripening as components of this pathway were down-regulated by MaMADS2 suppression. The mode of cytoskeleton involvement in fruit ripening remains unclear but presents a novel new frontier in ripening investigations. In summary, this project yielded functional understanding of the role and mode of action of MaMADS2 during ripening, pointing to both induction of ethylene and suppression of non-ethylene hormonal singling pathways. Furthermore, our data suggest important roles for cytoskeleton components and MaMADS5 in the overall banana ripening control network. Implications: The project revealed new molecular components/genes involved in banana ripening and refines our understanding of ripening responses in the peel and pulp tissues of this important species. This information is novel as compared to that derived from the more uniform carpel tissues of other highly studied ripening systems including tomato and grape. The work provides specific target genes for potential modification through genetic engineering or for exploration of useful genetic diversity in traditional breeding. The results from the project might point toward improved methods or new treatments to improve banana fruit storage and quality.
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Zchori-Fein, Einat, Judith K. Brown, and Nurit Katzir. Biocomplexity and Selective modulation of whitefly symbiotic composition. United States Department of Agriculture, June 2006. http://dx.doi.org/10.32747/2006.7591733.bard.

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Whiteflies are sap-sucking insects that harbor obligatory symbiotic bacteria to fulfill their dietary needs, as well as a facultative microbial community with diverse bacterial species. The sweetpotato whitefly Bemisia tabaci (Gennadius) is a severe agricultural pest in many parts of the world. This speciesconsists of several biotypes that have been distinguished largely on the basis of biochemical or molecular diagnostics, but whose biological significance is still unclear. The original objectives of the project were (i) to identify the specific complement of prokaryotic endosymbionts associated with select, well-studied, biologically and phylogeographically representative biotypes of B. tabaci, and (ii) to attempt to 'cure’ select biotypes of certain symbionts to permit assessment of the affect of curing on whitefly fitness, gene flow, host plant preference, and virus transmission competency.To identify the diversity of bacterial community associated with a suite of phylogeographically-diverseB. tabaci, a total of 107 populations were screened using general Bacteria primers for the 16S rRNA encoding gene in a PCR. Sequence comparisons with the available databases revealed the presence of bacteria classified in the: Proteobacteria (66%), Firmicutes (25.70%), Actinobacteria (3.7%), Chlamydiae (2.75%) and Bacteroidetes (<1%). Among previously identified bacteria, such as the primary symbiont Portiera aleyrodidarum, and the secondary symbionts Hamiltonella, Cardinium and Wolbachia, a Rickettsia sp. was detected for the first time in this insect family. The distribution, transmission, and localization of the Rickettsia were studied using PCR and fluorescence in situ hybridization (FISH). Rickettsia was found in all 20 Israeli B. tabaci populations screened as well as some populations screened in the Arizona laboratory, but not in all individuals within each population. FISH analysis of B. tabaci eggs, nymphs and adults, revealed a unique concentration of Rickettsia around the gut and follicle cells as well as its random distribution in the haemolymph, but absence from the primary symbiont housing cells, the bacteriocytes. Rickettsia vertical transmission on the one hand and its partial within-population infection on the other suggest a phenotype that is advantageous under certain conditions but may be deleterious enough to prevent fixation under others.To test for the possible involvement of Wolbachia and Cardiniumin the reproductive isolation of different B. tabacibiotypes, reciprocal crosses were preformed among populations of the Cardinium-infected, Wolbachia-infected and uninfected populations. The crosses results demonstrated that phylogeographically divergent B. tabaci are reproductively competent and that cytoplasmic incompatibility inducer-bacteria (Wolbachia and Cardinium) both interfered with, and/or rescued CI induced by one another, effectively facilitating bidirectional female offspring production in the latter scenario.This knowledge has implications to multitrophic interactions, gene flow, speciation, fitness, natural enemy interactions, and possibly, host preference and virus transmission. Although extensive and creative attempts undertaken in both laboratories to cure whiteflies of non-primary symbionts have failed, our finding of naturally uninfected individuals have permitted the establishment of Rickettsia-, Wolbachia- and Cardinium-freeB. tabaci lines, which are been employed to address various biological questions, including determining the role of these bacteria in whitefly host biology.
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Comparison of mechanical behavior between longitudinal lap-welded joints and transverse fillet welded joints of high strength steel. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.302.

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Mechanical behavior of twenty-eight longitudinal lap-welded joints made of high strength steels (HSS) under tension load was investigated by experimental study. Weaknesses due to traditional deformation measurements for fillet welded joints can be perfectly solved by digital image correlation techniques (DIC). The effect of parameters (e.g. weld size, weld length and mismatch ratio) on mechanical properties (e.g. ultimate strength, failure modes, weld ductility and fracture angle) of longitudinal fillet welds and transverse fillet welds, which was introduced in detail in previous work by the authors, were compared. Generally, because of the difference on the combination of shear force and tension force, the fracture angle of longitudinal welded specimens (around 50) were much more divergent from transverse welded specimens (around 20) even though both of them failed at welded zone (welded zone only refers to weld metal in this paper), resulting that the mean strength of longitudinal welded specimens were only 0.58 time of transverse welded specimens. Conversely, the mean deformation capacity of longitudinal welded specimens was almost 4.0 times of transverse welded specimens. Moreover, it was confirmed that the predicted loads of EC3 and AISC Specification were close and slightly conservative for all specimens.
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