The aboral nervous system of Marsupiocrinus Morris / C. R. C. Paul. --

Paul, Cigia

doi:10.5962/bhl.title.5437

Cited by 20 publications

(28 citation statements)

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“…Though quantitative analysis of discrete characters has long been an essential component of systematic biology (31,32) and macroevolution (7,8,18), previous emphasis has been on classification, genealogy, and evolutionary rates rather than on secular patterns of morphological diversity. Analysis of blastozoans has focused mainly on descriptive and diagnostic characters at lower taxonomic levels (27,(33)(34)(35), although the class Blastoidea has been studied by cladistic (36) and morphometric (16) methods, and the entire subphylum has been analyzed cladistically (30).…”

Section: Blastozoan Morphologymentioning

confidence: 99%

Paleozoic record of morphologica diversity in blastozoan echinoderms.

Foote

1992

Proc. Natl. Acad. Sci. U.S.A.

128

116

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There has been extensive debate about the magnitude and implications of morphological diversity in early Paleozoic animals, with some workers using apparently rapid initial diversification to infer unusual evolutionary processes. Analysis of discrete morphological characters shows that initial morphological diversification in the echinoderm subphylum Blastozoa was so pronounced that morphological diversity relative to taxonomic diversity was greatest in the Cambrian, whereas morphological diversity itself was greatest in the Middle and Upper Ordovician. Thus, a small number of Cambrian taxa sparsely occupied a large range in morphological space, whereas subsequent diversification involved expansion and filling of morphospace. A measure of clade-shape asymmetry and a method for statistical testing of lade shape are used to show that morphological diversity is significantly concentrated early in the history of the Blastozoa. The subphylum represents the highest biologic level at which temporal patterns of morphological diversity have been analyzed. Because this study is based on explicit morphological analysis, not taxonomic proxies for morphological diversity, the results are not artifacts of taxonomic practice.The early Paleozoic represents an extraordinary phase of life's history, involving extensive radiation of basic body plans, macroevolutionary response to vast ecological opportunities, and, arguably, substantial genomic evolution (1-14). Patterns of morphological diversity are central to our understanding of such large-scale evolutionary processes in early metazoans, but very little of our knowledge is based on direct analysis of morphology. Taxonomic diversity is often used to study the radiation of form but provides only an imperfect proxy for morphological diversity (2,4,(15)(16)(17). In fact, it is discrepancies between morphological and taxonomic diversity that may most clearly illuminate the early metazoan radiations (2-5, 15, 16).Echinoderms are a major component of the early Paleozoic radiation. Previous studies have emphasized the pace of morphological evolution in echinoderms based on the temporal occurrence of novelties (8, 18). Such an approach is inadequate for assessing diversity. Each organism consists of primitive and derived characters; therefore, exclusive focus on novelties would mean that different characters were studied for each species, largely defeating the purpose of considering all species simultaneously. Moreover, taxonomic turnover plays an important role in patterns of diversity. For example, a clade that contains lineages with the primitive and derived states of a character represents greater morphological diversity than a similar clade in which lineages with the primitive state have become extinct, leaving only lineages with the derived state. Study of novelties alone would overlook this important distinction. For these reasons, analyses presented here are based on quantification of primitive and derived aspects of morphology.Because it is difficult to quantify organi...

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Section: Blastozoan Morphologymentioning

confidence: 99%

Paleozoic record of morphologica diversity in blastozoan echinoderms.

Foote

1992

Proc. Natl. Acad. Sci. U.S.A.

128

116

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“…4,7,8 This had led to significant effort toward developing chemicals to inhibit crystal growth (scale inhibitors) or to dissolve already-grown crystals (scale dissolvers). 7,9,10 There have been many experiments to understand the morphology of barite crystals, 11 the nucleation and crystal growth process of barite, 12,13 and the morphology and growth rate of etch pits generated during the dissolution of barite. [14][15][16][17][18][19][20][21] These processes are known to be affected by organic and inorganic additives [22][23][24][25][26] or surfactants, 27 which should provide insight for the rational design of more efficient inhibitors and dissolvers.…”

Section: Introductionmentioning

confidence: 99%

The MSXX Force Field for the Barium Sulfate−Water Interface

et al. 2002

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A new force field (MSXX FF) was developed for barium sulfate (BaSO 4 ) to reproduce the experimental properties of BaSO 4 crystal (density, lattice energy, compressibility, and vibrational spectrum) and to describe properly the interaction between BaSO 4 and water (binding energies and interatomic distances of Ba(H 2 O) 8 2+ and (SO 4 )(H 2 O) 6 2-clusters determined from ab initio quantum mechanics calculations). Using this FF in combination with F3C FF for water, the surface energies for several surfaces of BaSO 4 were examined both in a vacuum and in the presence of an explicit water bath in contact with them. The same level of FF's are also reported for CaSO 4 and SrSO 4 .

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“…Much evidence now supports the observation that T cells and their subsets developed in vitro in an Ag-specific fashion can be employed in conjunction with I L 2 in as adoptive immunotherapy for infectious diseases and malignancies [12,[31][32][33]. In addition, as shown here, the combination of IL 2 administration and an IL 2-dependent, M. paratbc Ag-specific CD4+ T cell line is effective therapy for restoring age-associated impaired local (gut-mucosal) immune responses to enterically primed Ag, to the condition of young adult mice.…”

Section: Discussionmentioning

confidence: 99%

“…Successful adoptive transfer treatment thus depends on the source of Ag-specificT cells employed, and also on the route of transfer [33]. Because of these problems in adoptive transfer, we preliminarily evaluated the homing capability of in vitro expanded Ag-specific Th cells derived from GALT.…”

Section: Discussionmentioning

confidence: 99%

Correction of antigen‐specific T cell defects in aged murine gut‐associated lymphoid tissues an immune intervention by combined adoptive transfer of an antigen‐specific immunoregulatory CD4 T cell subset and interleukin 2 administration

Kawanishi

Ajitsu

1991

Eur J Immunol

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Gut-associated lymphoid tissues (GALT) from aged mice enterically immunized with Mycobacterium paratuberculosis protoplasmic antigen show hyperreactive humoral immune responses; this hyperresponsiveness can be corrected to a considerable extent, but not entirely, by systemic administration of interleukin 2 (IL 2) alone. The aim of the present study was to determine further whether the hyperreactivity in the antigen-specific humoral immune responses in aged GALT could be fully restored by adoptive transfer of in vitro expanded antigen-specific IL 2-dependent helper (CD4+VV-) T cells from GALT in conjunction with recombinant IL 2 administration. The results show that the age-associated hyperresponsiveness in gut mucosal antigen-specific humoral immune responses can be entirely corrected by adoptive transfer with the antigen-specific GALT T helper cells together with in vivo IL 2 administration. The mechanism of this restoration involves reversal of the decline in antigen-specific CD8+ suppressor T cell functions in aged GALT.

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The aboral nervous system of Marsupiocrinus Morris / C. R. C. Paul. --

Abstract: See oe ane me tad Fo b-in) Boo 0 seta net Wakahe' Bnasertes a pn Pe rr me fala rp a Sie Gok aehe. :

Cited by 20 publications

References 1 publication

Paleozoic record of morphologica diversity in blastozoan echinoderms.

Paleozoic record of morphologica diversity in blastozoan echinoderms.

The MSXX Force Field for the Barium Sulfate−Water Interface

Correction of antigen‐specific T cell defects in aged murine gut‐associated lymphoid tissues an immune intervention by combined adoptive transfer of an antigen‐specific immunoregulatory CD4 T cell subset and interleukin 2 administration

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