113,437 research outputs found
Fistulotrypa Bassler 1929
No full textGenus Fistulotrypa Bassler, 1929 TYPE SPECIES. — Fistulotrypa ramosa Bassler, 1929 by original designation from the Lower Permian of Timor.Published as part of Nekhorosheva, Lyudmila V., 2002, Paleozoic Bryozoa from Severnaya Zemlya (Russian Arctic), pp. 317-327 in Geodiversitas 24 (2) on page 320, DOI: 10.5281/zenodo.537816
Halloporina Bassler 1913
No full textGenus Halloporina Bassler, 1913 TYPE SPECIES. — Calloporina crenulata Ulrich, 1893 by original designation from the Middle Ordovician, Trentonian of Minnesota, USA.Published as part of Nekhorosheva, Lyudmila V., 2002, Paleozoic Bryozoa from Severnaya Zemlya (Russian Arctic), pp. 317-327 in Geodiversitas 24 (2) on page 322, DOI: 10.5281/zenodo.537816
Repressors of Quorum-Sensing-Induced Aggregation in Vibrio Cholerae
No full textVibrio cholerae is the pathogen responsible for the disease cholera. To cause disease, V. cholerae must have the ability to form surface-attached multicellular communities called biofilms. The formation of surface biofilms is regulated by quorum sensing (QS). QS is a process in which bacteria collectively regulate gene expression in response to the secretion, accumulation, and detection of signaling molecules called autoinducers. The low cell density QS-state promotes biofilm formation while the high cell density QS-state promotes biofilm dispersal. Previous work in the Bassler laboratory identified an aggregation program in V. cholerae that occurs in liquid in the high cell density QS-state and is independent of components known to be required for surface biofilm formation. In this previous work, members of the Bassler group identified genes that function as activators of aggregation. In this study, I identified putative repressors of aggregation by performing a transposon mutagenesis screen in a low cell density-locked QS-state V. cholerae strain, a genetic background in which cells are normally unable to aggregate. This screen was successful, and I discovered two genes that act as repressors of aggregation: fbp and clpX. I validated both fbp and clpX and eliminated some mechanisms by which these genes may be regulating aggregation, which included control of the levels of O1 antigen and modulation of the QS-state of the cells. These findings increase our understanding of mechanisms that V. cholerae uses to transition between the planktonic and community phases of its life cycle
Exechonella Canu & Bassler in Duvergier 1924
No full textExechonella sp. ( Fig. 2E) Material examined. Abrolhos Bank, Bahia State, Brazil: MNRJ-Bry1375, Parcel dos Abrolhos, 4 m depth, February 2014, col. R. Moura, G. Amado-Filho & A. Bastos. Description. Small encrusting fragments comprising a few zooids (Fig. 2E). Autozooids rhomboidal, longer than wide, separated by deep fissures; frontal wall convex, perforated by large circular pores surrounded by a smooth flat collar. Orifice almost quadrate, as wide as long; condyles, avicularia, kenozooids and ovicells not observed. Geographic distribution. Abrolhos Bank, Bahia State (Bastos et al. 2018; present study). Remarks. Due to the poor preservation and difficulty of obtaining colonies from the inner core, this specimen can be identified only to genus level. According to Cáceres-Chamizo et al. (2017), two species of Exechonella are confirmed to occur in Brazilian waters: E. brasiliensis Canu & Bassler, 1928a, described from the Bahia coast (Canu & Bassler 1928a; Vieira et al. 2008), and E. vieirai Cáceres-Chamizo et al. 2017, described from Alagoas and Bahia states (Vieira et al. 2008; Winston et al. 2014; Almeida et al. 2015a).Published as part of Ramalho, Laís V., Taylor, Paul D., Moraes, Fernando Coreixas, Moura, Rodrigo, Amado-Filho, Gilberto M. & Bastos, Alex C., 2018, Bryozoan framework composition in the oddly shaped reefs from Abrolhos Bank, Brazil, southwestern Atlantic: taxonomy and ecology, pp. 155-186 in Zootaxa 4483 (1) on page 159, DOI: 10.11646/zootaxa.4483.1.6, http://zenodo.org/record/143757
Calyptotheca ornatissima Canu & Bassler 1928, n. comb.
No full textCalyptotheca ornatissima (Canu & Bassler, 1928a) n. comb. (Figs. 48–53; Table 5) Gemelliporidra ornatissima Canu & Bassler, 1928a: 79, pl. 5, figs. 1–2; Almeida et al. 2015b: 5. Material examined. UFBA 605, Camamu Bay, 13°53’S, 38°59’W, 18–20 m, coll. October 2012 (on sponge Timea sp.); UFBA 1178, Camamu Bay, 13°53’S, 38°59’W, 18–20 m, coll. October 2012 (on sponge Chondrilla nucula); UFBA 1179, Camamu Bay, 13°53’S, 38°59’W, 18–20 m, coll. October 2012 (on sponge Timea sp.). Comparative material. USNM 8554, Gemelliporidra ornatissima, holotype, F. Canu & R. Bassler det., Bahia, Brazil, 49 m, coll. 1877 by Steamer Norseman. Description. Colony encrusting, orange in life. Zooidal skeleton orange and avicularia white. Autozooids almost quadrangular to rectangular, rarely polygonal, limited by distinct raised walls. Frontal shield heavily calcified, tuberculate, entirely punctured by 20–50 pseudopores. Primary orifice small relative to frontal shield length, dimorphic (shorter in ovicelled zooids than infertile ones), subcircular, sunken, rounded anter separated from widely and shallowly V-shaped poster by two strong rounded condyles placed at the proximal quarter of orifice; lunula restricted to distal edge of the orifice. Proximal border of orifice slightly raised, often surrounded by short tubercles and with a suboral umbo; suboral umbo often carrying a laterally oriented avicularium with an elongated triangular rostrum. Frontal avicularia similar in shape to suboral avicularium, common, scattered throughout the colony, frequently near zooidal margins and also above ovicells. One elongate avicularium often placed at latero-distal zooidal margin, directed distally or proximally, rostrum acute and curved, with complete crossbar; sometimes a curved avicularium seen at proximal zooidal margin. Vicarious avicularium large, longer than wide, rostrum somewhat spatulate, oblong with concave lateral edges; palate calcified in distal third with rounded proximal margin, thinning proximally along lateral edges; mandible hinged on two strong square condyles situated in the corners of the straight proximal end of avicularium; cystid surrounding almost the entire avicularium except in the rounded distal edge, frontal shield similar to autozooid. Ovicell prominent, ooecia globose, same tuberculate and porous calcification as autozooids, secondary calcification cormidial (i.e. with Y-shaped suture lines of calcification), closed by zooidal operculum. Orifice dimorphic, wider than in autozooids. Remarks. Calyptotheca ornatissima n. comb. has not been figured since its original description (Canu & Bassler 1928a), and only recently it has been reported again from Brazilian coast (Bahia) by Almeida et al. (2015b). Although it was originally assigned to the genus Gemelliporidra Canu & Bassler, 1927, the morphology of orifice (proximal sinus, condyles, lunula and dimorphism; figs. 49, 51, 52 and 53), avicularia (both adventitious and vicarious; figs. 50–53), and ovicell (calcification similar to autozooidal frontal shield; secondary calcification cormidial; figs. 51 and 53) (Cumming & Tilbrook 2014; Cumming 2015) suggest that it belongs to the genus Calypthoteca. The species is characterized by multilayered orange colonies with white spots representing the avicularia and ovicells (Canu & Bassler 1928a; figs. 52 and 53). It can be distinguished from other Calyptotheca by its avicularia (suboral, frontal, lateral and vicarious; Figs. 49–50). Other species of the genus were already reported in association with corals, several invertebrates such as other bryozoans and gorgonians, shells, rocks and kelps (e.g., Winston 1986; Florence et al. 2007; Cumming & Tilbrook 2014). Colonies of Calyptotheca ornatissima n. comb. examined here are robust and covered lower and upper portions of the smooth-textured sponges Chondrilla nucula Schmidt, 1862 (Fig. 13) and Timea sp. (Fig. 16), representing the first record of the association of Calyptotheca ornatissima n. comb. with sponges. Distribution. Atlantic: endemic to Brazil (Bahia) (Vieira et al. 2008).Published as part of Almeida, Ana C. S., Souza, Facelucia B. C., Menegola, Carla & Vieira, Leandro M., 2017, Diversity of marine bryozoans inhabiting demosponges in northeastern Brazil, pp. 281-323 in Zootaxa 4290 (2) on pages 300-302, DOI: 10.11646/zootaxa.4290.2.3, http://zenodo.org/record/89271
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Arthropoma cecilii : Canu & Bassler 1929
No full textArthropoma cecilii (Audouin, 1826) ( Figs 5H, 7G) Flustra cecilii Audouin, 1826: 239. Arthropoma cecilii: Canu & Bassler, 1929: 296; Marcus, 1937: 96, fig. 49; 1955: 297; Vieira et al., 2008: 31; Ramalho et al., 2011: 777, fig. 5; Bastos et al., 2018: table 1. Material examined. Abrolhos Bank, Bahia State, Brazil: MNRJ-Bry1376, Parcel dos Abrolhos, 4 m depth, February 2014, col. R. Moura, G. Amado-Filho & A. Bastos. Short description. Encrusting colonies, forming single layers (Fig. 5H); orange in colour with white ovicells when alive (Fig. 7G). Autozooids hexagonal to rectangular, frontal wall perforated by large circular pseudopores, except in a central area beneath the orifice. Ovicell hyperstomial. Geographic distribution. Espírito Santo, Rio de Janeiro and São Paulo states (Marcus 1937, 1955; Ramalho et al. 2011), Abrolhos Bank, Bahia State, Brazil (Bastos et al. 2018; present study). Remarks. Arthropoma cecilii has a worldwide distribution, although its apparent cosmopolitan nature deserves re-evaluation. In the present study, colonies were recorded only at 15 m deep, inside the cores and on the surface of the reefs; those on the external reef surfaces were alive and fertile.Published as part of Ramalho, Laís V., Taylor, Paul D., Moraes, Fernando Coreixas, Moura, Rodrigo, Amado-Filho, Gilberto M. & Bastos, Alex C., 2018, Bryozoan framework composition in the oddly shaped reefs from Abrolhos Bank, Brazil, southwestern Atlantic: taxonomy and ecology, pp. 155-186 in Zootaxa 4483 (1) on pages 170-176, DOI: 10.11646/zootaxa.4483.1.6, http://zenodo.org/record/143757
Investigating the Function of LuxT: A Quorum-Sensing Transcription Factor in Vibrio species
No full textBacteria coordinate population-wide gene expression using a cell-cell communication process called quorum-sensing (QS). QS involves the production, release, and group-wide detection of small molecules called autoinducers. In the model marine bacterium Vibrio harveyi, the QS regulatory system relies on the production of five small regulatory RNAs (Qrr1-5) that are produced at low cell density when autoinducer concentrations are low. Recently, the Bassler group identified LuxT as a transcriptional repressor of qrr1, encoding one of the Qrr sRNAs. The possibility that LuxT regulates genes in addition to qrr1 has not been investigated. This thesis aims to further the understanding of the role of LuxT through primary literature research regarding QS and LuxT and analysis of transcriptomic studies. RNA-Sequencing data revealed that LuxT regulates 264 genes in V. harveyi, including genes necessary for type III secretion, type VI secretion, siderophore production, and production of the aerolysin pore-forming toxin, all of which are known virulence factors in Vibrio bacteria. These results demonstrate that LuxT is a global regulator in V. harveyi and the findings highlight the interconnected relationship between QS and virulence. Because LuxT is conserved among Vibrios, it is predicted that LuxT regulates the same behaviors in other species, including in the human pathogens Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus. Thus, this study is particularly relevant to public health initiatives that aim to develop novel therapies for combating bacterial diseases and address the antibiotic resistance crisis
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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