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New species of Acoela (Acoelomorpha) from the Gulf of California
No full textHooge, Matthew D., Eppinger, Neil (2005): New species of Acoela (Acoelomorpha) from the Gulf of California. Zootaxa 1009 (1): 1-14, DOI: 10.11646/zootaxa.1009.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.1009.1.
FIGURE 4 in New species of Acoela (Acoelomorpha) from the Gulf of California
No full textFIGURE 4. Isodiametra bajaensis sp. nov.; reconstructions to show arrangement of organs. A. Dorsal reconstruction of whole organism. B. Sagittal reconstruction of whole organism. bn, bursal nozzle; cs, digestive central syncytium; e, egg; fg, frontal gland; gp, gonopore; gr, granules; gs, glandular secretions; m, mouth; mg, mucoid gland; p, penis; sb, seminal bursa; sph, vaginal sphincter; st, statocyst; sv, seminal vesicle; t, testes.Published as part of Hooge, Matthew D. & Eppinger, Neil, 2005, New species of Acoela (Acoelomorpha) from the Gulf of California, pp. 1-14 in Zootaxa 1009 (1) on page 7, DOI: 10.11646/zootaxa.1009.1.1, http://zenodo.org/record/504887
Praeaphanostoma gusana Hooge & Eppinger 2005, sp. nov.
No full textPraeaphanostoma gusana sp. nov. (Figs. 7,8) Type Material. Holotype. AMNH PLATY 1664, set of 1.5µmthick serial sagittal sections of epoxyembedded specimen stained with toluidine blue. Paratype. AMNH PLATY 1665, set of 1.5µmthick serial sagittal sections of epoxyembedded specimen stained with toluidine blue. Type Locality. San Felipe, Baja California, from intertidal fine sand from the northwest corner of San Felipe Bay (31°01'03.4" N, 114°49'50.3" W). Other Material Examined. Photographs of living specimens in squeeze preparations, and one set of 1.5µmthick serial sagittal sections of epoxyembedded specimen. Etymology. Species name is a derivation of the Spanish gusano, worm. Description. Mature, living specimens ~ 400 µm long and ~ 150 µm wide (Figs. 7A, 8A, B). Preserved specimens contracted to ~ 260 µm long. Anterior and posterior ends rounded. Body cylindrical. Epidermis completely ciliated. Rhabdoid glands present. Body colorless in transmitted light, but digestive syncytium with yellow coloration. Frontal organ well developed. Cell bodies of frontal glands positioned ~ 110 µm behind frontal pore (Fig. 7B). Mouth opening on ventral surface, middle of body. Digestive central syncytium extends from frontal glands posteriorly to male copulatory apparatus. Ovaries paired, ventral; extend from frontal glands posteriorly to seminal bursa (Figs. 7A, B). Testes paired, lateral to eggs; separate from ovary. Testes extend from frontal gland posteriorly to level of seminal bursa (Figs. 7A, B). Common gonopore opens anteriorly to vagina and posteriorly to male copulatory apparatus (Figs. 7A, 8C). Narrow vagina extends anteriorly along posterior side of seminal vesicle; opens to seminal bursa (Figs. 7B, 8C). Seminal bursa with welldefined bursa wall. Bursa filled with sperm in living specimens, but sperm absent in fixed specimens (Fig. 8C). Bursa without bursal appendage. Gonopore opens directly to welldeveloped, curved penis with outer longitudinal muscles and inner circular muscles (Figs. 7B, 8C). Tip of penis with a cluster of granules (Kornsekret, sensu Dörjes 1968). Penis invaginated into muscular seminal vesicle filled with sperm clustered to anterior side of penis. Remarks. The genus Praeaphanostoma is composed of 10 species that can be distinguished from other members of the Isodiametridae by their possession of a walled seminal bursa that lacks an appendage such as a bursal nozzle, and their lack of eyespots (as found in Ancylocirrus), or a long tubular, ciliated vagina (as found in Bursosaphia). Praeaphanostoma gusana has a single gonopore, a slightly curved penis with granules clustered at the tip of the lumen, and is without a sphincter on the vagina. While all of these are common features in this genus, no other member of Praeaphanostoma has this exact suite of characters.Published as part of Hooge, Matthew D. & Eppinger, Neil, 2005, New species of Acoela (Acoelomorpha) from the Gulf of California, pp. 1-14 in Zootaxa 1009 (1) on pages 10-13, DOI: 10.11646/zootaxa.1009.1.1, http://zenodo.org/record/504887
Haplogonaria amarilla Hooge & Eppinger 2005, sp. nov.
No full textHaplogonaria amarilla sp. nov. (Figs. 1–3) Type Material: Holotype. AMNH PLATY 1658, one set of 1.5µmthick serial sagittal sections of epoxyembedded specimens stained with toluidine blue. Paratypes. AMNH PLATY 1659, one set of 1.5µmthick serial sagittal sections of epoxyembedded specimens stained with toluidine blue, and AMNH PLATY 1660, epoxyembedded whole mount. Type Locality. San Felipe, Baja California, medium grained sand from a small pool of standing sea water at the high intertidal from the south side of San Felipe Bay (30°58'35.1"N, 114°48'22.6"W). Other Material Examined. Living specimens in squeeze preparations; three sets of 1.5µmthick serial sections of epoxyembedded specimens; several whole mounts for fluorescence imaging of musculature. Etymology. Species name is a derivation of the Spanish amarillo, yellow, referring to the species body color. Description. Mature, living specimens up to 650 µm long and 150 µm wide (Figs. 1A, 2). Preserved specimens contracted to approximately 360 µm long and 140 µm wide (Figs. 1B, 3). Body cylindrical. Anterior and posterior ends rounded. Body color yellow by transmitted light. Epidermis completely ciliated. Many large rhabdoid glands present; mostly concentrated at anterior end (Figs. 1, 2). Musculature with circular muscles that encircle the body along entire length of animal; straight longitudinal muscles present between frontal organ and anterior edge of mouth; longitudinalcrossover muscles (fibers with a longitudinal orientation anteriorly, but bend medially to cross diagonally) present in both dorsal and ventral body wall; anterior end with ventral diagonal muscles positioned between outer circular and inner longitudinal muscles (Fig. 3A). Frontal organ well developed; cell bodies of frontal glands positioned ~ 100 µm behind frontal pore (Figs. 1B, 2B). Mouth opening on ventral surface, middle of body. Digestive central syncytium extends from posterior end of frontal glands to level of seminal vesicle. Ovary presumed to be unpaired, ventral; no more than two eggs —positioned medially—discernible in live and sectioned material (Figs. 1, 2A, C). Testes paired, dorsal, compact; separate from ovary. Testes extend anteriorly to level of mouth and posteriorly to male copulatory organ. Common gonopore on ventral surface opens anteriorly to spermfilled seminal vesicle composed of thin layer of muscle and surrounded on ventral and posterior sides by several conspicuous nuclei (Figs. 1B, 2B, 3B). Gonopore opens posteriorly to illdefined, weakwalled vagina that runs anteriorly over dorsal side of seminal vesicle to spermfilled seminal bursa; bursa with welldeveloped bursal wall (Figs. 1B, 2B). Remarks. There are presently 14 described species of Haplogonaria that are united in having an unpaired ovary, paired testes, and a seminal bursa that lacks a bursal nozzle. Some species, such as H. arenaria (Ax, 1959), H. elegans Faubel, 1976, and H. stradbrokensis Hooge, 2003 have a nonmuscular, or weakly muscular seminal vesicle, while other species, such as H. phyllospadicis Hooge & Tyler, 2003, and H. simplex Dörjes, 1968, have a strongly muscular seminal vesicle. H. amarilla is more like the former, with only a very thin layer of muscle contributing to the wall of the seminal vesicle (Fig. 3B). It is unusual for members of the Haploposthiidae to have a vagina positioned as it is in this species; that is, opening posterior to, and passing dorsally over the seminal vesicle. Within the Haplogonaria, this configuration of the vagina is shared only with H. sinubursalia Dörjes, 1968. In other regards, the vagina and bursa of H. amarilla are dissimilar to that of H. sinubursalia, which has a vagina filled with granular secretions (vesicula granulorum), and a bursa bearing a cap of cells on its proximal wall; both of these features are lacking in H. amarilla.Published as part of Hooge, Matthew D. & Eppinger, Neil, 2005, New species of Acoela (Acoelomorpha) from the Gulf of California, pp. 1-14 in Zootaxa 1009 (1) on pages 2-6, DOI: 10.11646/zootaxa.1009.1.1, http://zenodo.org/record/504887
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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