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Search Results: 1 - 10 of 159567 matches for " Jonathan H Geisler "
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A supermatrix analysis of genomic, morphological, and paleontological data from crown Cetacea
Jonathan H Geisler, Michael R McGowen, Guang Yang, John Gatesy
BMC Evolutionary Biology , 2011, DOI: 10.1186/1471-2148-11-112
Abstract: We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs) from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters) and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML) searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses.The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene taxa included in our study fell outside crown Mysticeti and crown Odontoceti, suggesting that these two clades radiated in the late Oligocene or later, contra some recent molecular clock studies. Our trees also imply that many character states shared by river dolphins evolved in their oceanic ancestors, contradicting the hypothesis that these characters are convergent adaptations to fluvial habitats.It has been 12 years since the publication of Messenger and McGuire [1], the first major effort to develop a phylogenetic hypothesis for crown Cetacea (Neoceti) based on a combined phylogenetic analysis of morphological and molecular charact
General properties and analytical approximations of photorefractive solitons
A. Geisler,F. Homann,H. -J. Schmidt
Physics , 2003, DOI: 10.1016/j.optcom.2004.04.054
Abstract: We investigate general properties of spatial 1-dimensional bright photorefractive solitons and suggest various analytical approximations for the soliton profile and the half width, both depending on an intensity parameter r.
Single-Port Laparoscopy, NOTES, and Endoluminal Surgery
Pedro F. Escobar,Jihad H. Kaouk,Daniel Geisler,Matthew Kroh
Diagnostic and Therapeutic Endoscopy , 2010, DOI: 10.1155/2010/710130
Constructed Ponds and Small Stream Habitats: Hypothesized Interactions and Methods to Minimize Impacts  [PDF]
Jonathan D. Ebel, Winsor H. Lowe
Journal of Water Resource and Protection (JWARP) , 2013, DOI: 10.4236/jwarp.2013.57073

Extensive research has been conducted on how large impoundments and reservoirs affect hydrologic, geomorphologic and ecological processes in downstream ecosystems. Surprisingly, few studies have addressed the effects of smaller impoundments and constructed ponds. Pond construction has been considered an important tool for managers seeking to reduce sediment, nutrient and pollutant loads, and increase habitat heterogeneity in streams in an effort to conserve or enhance aquatic species diversity. However, we lack information on the interaction between ponds and stream habitats, which may compromise the efficacy of conservation efforts. The objective of this review is to outline possible physical and biological changes to stream ecosystems resulting from pond construction. Greater understanding of how ponds influence watershed processes at various spatial scales is crucial to evaluating the effects of constructed ponds on stream ecosystems.

Revisitando o conceito de cidadania: notas para uma educa??o politécnica
Geisler, Adriana;
Trabalho, Educa??o e Saúde , 2006, DOI: 10.1590/S1981-77462006000200008
Abstract: in opposition to a community and school project which have been denying the effective citizenship to a great contingent of youth and brazilian workers, the polytechnic conception emerges as a part of an emancipating project which is far from the liberal ideology and from its reflexes on the education and work fields. retaking the issue of the citizenship meaning nowadays, this text aims to identify to which citizenship concept the polytechnic conception belongs, considering the educational practices field and its connection to the current aspect of the world of work.
Expression of a prokaryotic P-type ATPase in E. coli Plasma Membranes and Purification by Ni2+-affinity chromatography
Geisler Markus
Biological Procedures Online , 1998, DOI: 10.1251/bpo9
Abstract: In order to characterize the P-type ATPase from Synechocystis 6803 [Geisler (1993) et al. J. Mol. Biol. 234, 1284] and to facilitate its purification, we expressed an N-terminal 6xHis-tagged version of the ATPase in an ATPase deficient E. coli strain. The expressed ATPase was immunodetected as a dominant band of about 97 kDa localized to the E. coli plasma membranes representing about 20-25% of the membrane protein. The purification of the Synecho-cystis 6xHis-ATPase by single-step Ni-affinity chromatography under native and denaturating conditions is described. ATPase activity and the formation of phosphointermediates verify the full function of the enzyme: the ATPase is inhibited by vanadate (IC50= 119 &mgr;M) and the formation of phosphorylated enzyme intermediates shown by acidic PAGE depends on calcium, indicating that the Synechocystis P-ATPase functions as a calcium pump.
Josep Pla und Montaigne. Eine Skizze [Josep Pla and Montaigne. An outline]
Geisler, Eberhard
Zeitschrift für Katalanistik , 2006,
Abstract: Joseph Pla was a great admirer of French literature. As such, the writer Michel de Montaigne was of particular importance to him. Accordingly, Pla once remarked that he owed a plethora of fundamental philosophical knowledge to the author of Essais, as well as the ability to weigh and judge. In Pla’s opinion, the Frenchman was an ideal representative of a non-bombastic view of man and as a moralist. In the following passages, three further relations between the two authors will be reflected upon. To begin with, the depiction of the self and the emerging difficulty with the same phenomenon shall be treated; since the ego is not always present to itself, it vacillates between authenticity on the one hand, and convention and role on the other. Therefore the topic of the instability of human relation stands at the center of Montaigne’s observations as well as of Pla’s, which can evidently be traced in his tale “Contraban”; the theme of instability is counterbalanced by a certain consistency in these authors’ views. At last it demonstrates that both authors tend, with regard to their view of man, towards a policy of power decomposition. Thus they establish, with their understanding of nature and health, an inevitable counterimage (since Pla is defined by a profession towards antique cynicism and its use of the verb “badar”).
Wer war Joan Sales? Hinweis auf einen Autor [Who was Joan Sales? Hints on an author]
Geisler, Eberhard
Zeitschrift für Katalanistik , 2010,
Abstract: The major work of Joan Sales (1912-1983), the novel "Incerta glòria", has suffered a peculiar fate. In spite of the high praise expressed by Mercè Rodoreda in a letter to the author, the work was little acknowledged in Spain (the French translation, on the other hand, was more successful and was compared with the best novels by Bernanos). Only in recent years have critics increasingly surfaced, paying a befitting tribute to the book as a masterpiece and as a unique panorama of the Spanish Civil War and – along with the sequel "El vent de la nit" – the years of Francoism. The novel is clearly written from the view of the vanquished. This article outlines the life of Sales and demonstrates his approach of a critical, liberal and Catalan intellectual. As will be shown, the chief aim of the author is to experience and to seek the abundance of an intensive life, to create an intensity which is expressed in his literary style that is full of metaphors and, particularly, contrasts. A longer section of the article is dedicated to the vestiges of Kierkegaard in the novel. Within this it is above all the figure of the intellectual Soleràs who seems influenced by the Danish philosopher and progenitor of existentialism. The religious aspect is treated by Sales with particular tolerance. He rejects any form of power and hierarchy within religion and represents the theology of the cross, by attributing Christ as the God of the conquered. He defends a version of Catholicism which displays ecumenical traits. Of course, the classical criticism of religion (which viewed the childhood soul of the believer as a scandal) can be applied to the author, but he remains true to the spirit of the Gospel. At the end of the essay an eye is cast over poetry written by the author, in addition to his novel, and the implied attitude towards surrealism is investigated. From this a certain break with the surreal and the conception of the unconscious becomes evident. "Incerta glòria" is, by contrast, is monolithic and wholeheartedly successful. The novel encompasses the totality of the human and preaches a spirit for which any policies of exclusion are foreign.
Single-Port Laparoscopy, NOTES, and Endoluminal Surgery
Pedro F. Escobar,Jihad H. Kaouk,Daniel Geisler,Matthew Kroh,Amanda Nickles Fader,Tommaso Falcone
Diagnostic and Therapeutic Endoscopy , 2010, DOI: 10.1155/2010/710130
The Kinematics of the Globular Cluster System of NGC 5128 with a New, Large Sample of Radial Velocity Measurements
Kristin A. Woodley,Matias Gomez,William E. Harris,Doug Geisler,Gretchen L. H. Harris
Physics , 2010, DOI: 10.1088/0004-6256/139/5/1871
Abstract: New radial velocity measurements for previously known and newly confirmed globular clusters (GCs) in the nearby massive galaxy NGC 5128 are presented. We have obtained spectroscopy from LDSS-2/Magellan, VIMOS/VLT, and Hydra/CTIO from which we have measured the radial velocities of 218 known, and identified 155 new, GCs. The current sample of confirmed GCs in NGC 5128 is now 605 with 564 of these having radial velocity measurements. We have performed a new kinematic analysis of the GC system that extends out to 45 arcmin in galactocentric radius. We have examined the systemic velocity, projected rotation amplitude and axis, and the projected velocity dispersion of the GCs as functions of galactocentric distance and metallicity. Our results indicate that the metal-poor GCs have a very mild rotation signature of (26 pm 15) km/s. The metal-rich GCs are rotating with a higher, though still small signature of (43 pm 15) km/s around the isophotal major axis of NGC 5128 within 15 arcmin. Their velocity dispersions are consistent within the uncertainties and the profiles appear flat or declining within 20 arcmin. We note the small sample of metal-rich GCs with ages less than 5 Gyr in the literature appear to have different kinematic properties than the old, metal-rich GC subpopulation. The mass and mass-to-light ratios have also been estimated using the GCs as tracer particles for NGC 5128. Out to a distance of 20 arcmin, we have obtained a mass of (5.9 pm 2.0) x 10^(11) M_(sun) and a mass-to-light ratio in the B-band of 16 M_(sun)/L_(B,sun). Combined with previous work on the ages and metallicities of its GCs, as well as properties of its stellar halo, our findings suggest NGC 5128 formed via hierarchical merging over other methods of formation, such as major merging at late times.
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