873 research outputs found
A revision of Antarctic and some Indo-Pacific apodid sea cucumbers (Echinodermata: Holothuroidea: Apodida)
Eight new apodid species from Antarctica are described: myriotrochids Achiridota smirnovi sp. nov., Myriotrochus nikiae sp. nov., Prototrochus linseae sp. nov., Prototrochus barnesi sp. nov., and chiridotids Kolostoneura griffithsi sp.nov., Scoliorhapis bipearli sp. nov., Scoliorhapis massini sp. nov., Taeniogyrus prydzi sp. nov. Genera Scoliorhapis H. L. Clark, Taeniogyrus Semper and Trochodota Ludwig are reviewed. Scoliodotella Oguro is a junior synonym of Scoliorhapis H. L. Clark. Trochodota Ludwig type species is fixed as Holothuria (Fistularia) purpurea Lesson. Trochodota Ludwig is a junior synonym of Taeniogyrus Semper. Sigmodota Studer type species is fixed as Chiridota contorta Ludwig, and Sigmodota Studer is raised out of synonymy with Taeniogyrus Semper. Species assigned to Sigmodota are Chiridota contorta Ludwig, Taeniogyrus dubius H. L. Clark (as Sigmodota dubia) and Taeniogyrus magnibaculus Massin and Hétérier (as Sigmodota magnibacula). Non-Antarctic new genus Rowedota gen. nov. is erected with type species Taeniogyrus allani Joshua, and other assigned species Trochodota epiphyka O’Loughlin, Trochodota mira Cherbonnier, Trochodota shepherdi Rowe and Trochodota vivipara Cherbonnier. Trochodota species not assigned to Rowedota gen.nov. and Sigmodota Studer are assigned to Taeniogyrus Semper. Other Antarctic apodid species discussed are Myriotrochus antarcticus Smirnov and Bardsley, Myriotrochus hesperides O’Loughlin and Manjón-Cabeza and Taeniogyrus antarcticus Heding. Non-Antarctic apodid species discussed are Chiridota pisanii Ludwig, Chiridota australiana Stimpson and Trochodota maculata H. L. Clark. The spelling of the species name Myriotrochus macquariensis Belyaev and Mironov is corrected. A table with Antarctic Apodida species and their distributions is provided. A table with specimen and ossicle sizes for some Taeniogyrinae species is provided. A key to genera of Taeniogyrinae is provided. Species names are standardized to: macquariensis; studeri; theeli
The phyllophorid sea cucumbers of southern Australia (Echinodermata: Holothuroidea: Dendrochirotida: Phyllophoridae)
A new monotypic Phyllophoridae (Phyllophorinae) genus Phyllostauros, with author O’Loughlin, is erected for Thyone vercoi Joshua and Creed. We raise Phyllophorella Heding and Panning (subgenus of Phyllophorus Grube) to generic rank. The holotype and three paratypes of Phyllophorus ventripes Joshua and Creed are conspecific with Thyone vercoi Joshua and Creed. We make Phyllophorus ventripes Joshua and Creed a subjective junior synonym of Thyone vercoi Joshua and Creed. One paratype of Phyllophorus ventripes Joshua and Creed is conspecific with Phyllophorus thyonoides H. L. Clark. We reject the synonymy of Thyone okeni Bell with Thyone venusta Selenka. Twelve new species of Phyllophoridae are described for southern Australia, with author O’Loughlin: Lipotrapeza eichleri, Lipotrapeza litusi,Massinium melanieae, Massinium vimsi, Massinium watsonae, Phyllophorella notialis, Thyone flindersi, Thyone joshuai, Thyone kerkosa, Thyone spenceri, Thyone tourvillei, Thyonidiella kungi. Phyllophoridae species reported previously for southern Australia are reviewed: Lipotrapeza ventripes (Joshua and Creed); Lipotrapeza vestiens (Joshua); Neothyonidium dearmatum (Dendy and Hindle); Phyrella thyonoides (H. L. Clark); Thyone nigra Joshua and Creed; Thyone okeni Bell; Thyone vercoi Joshua and Creed. Species Phyrella thyonoides (H. L. Clark) is re-assigned to genus Phyllophorella Heding and Panning. A key is provided for the southern Australian species of Phyllophoridae. We acknowledge the rejection for nomenclatorial purposes by the ICZN (Opinion 417) of the publication by Oken 1815, and hence the current invalid statusof genus Thyone Oken. A petition has been sent to the ICZN for re-validation of Thyone Oken and we retain the use of Thyone Oken provisionally. The petition includes a similar request for re-validation of Psolus Oken
The paracaudinid sea cucumbers of Australia and New Zealand (Echinodermata: Holothuroidea: Molpadida: Caudinidae)
The four Paracaudina Heding species reported in Australia are reviewed: Paracaudina australis (Semper); Paracaudina chilensis (Müller); Paracaudina luticola Hickman; Paracaudina tetrapora (H. L. Clark). The New Zealand species Paracaudina coriacea (Hutton) is raised out of synonymy with the Chilean species Paracaudina chilensis (Müller). Both Paracaudina chilensis (Müller) and Paracaudina coriacea (Hutton) occur in New Zealand. The synonymy of the Chinese and Japanese species Paracaudina ransonnetii (Marenzeller) with Paracaudina chilensis (Müller) is maintained. Five new Caudinidae species are erected for Australia, with authors O’Loughlin and Barmos: Paracaudina ambigua, Paracaudina bacillis, Paracaudina cuprea, Paracaudina keablei, Paracaudina tripoda. A key is provided for Paracaudina species in Australia and New Zealand
Implementation of an education-focused PhD program in anatomy and cell biology at Indiana University: Lessons learned and future challenges
In 2008, the Indiana University School of Medicine, in collaboration with the School of Education, admitted its first student to a newly approved PhD program in Anatomy and Cell Biology focusing on educational research rather than biomedical research. The goal of the program is twofold: (1) to provide students with extensive training in all of the anatomical disciplines coupled with sufficient teaching experience to assume major educational responsibilities upon graduation and (2) to train students to conduct rigorous medical education research and other scholarly work necessary for promotion and tenure. The 90 credit hour curriculum consists of biomedical courses taught within the School of Medicine and education courses taught within the School of Education, including courses in health sciences pedagogy, curriculum development, learning theory, quantitative, and qualitative research methods, statistics, and electives. To date, 16 students have entered the program, seven have passed their qualifying examinations, and five have earned their PhD degrees. Four students have received national recognition for their educational research and four graduates have obtained faculty appointments. Going forward, we must adapt the program's biomedical course requirements to incorporate the new integrated curriculum of the medical school, and we must secure additional funding to support more students. Overcoming these challenges will enable us to continue producing a small but stable supply of doctoral-level anatomy educators for a growing academic market
Are Horned Particles the Climax of Hawking Evaporation?
We investigate the proposal by Callan, Giddings, Harvey and Strominger (CGHS)
that two dimensional quantum fluctuations can eliminate the singularities and
horizons formed by matter collapsing on the nonsingular extremal black hole of
dilaton gravity. We argue that this scenario could in principle resolve all of
the paradoxes connected with Hawking evaporation of black holes. However, we
show that the generic solution of the model of CGHS is singular. We propose
modifications of their model which may allow the scenario to be realized in a
consistent manner.Comment: 26 page
Black Hole Remnants and the Information Puzzle
Magnetically charged dilatonic black holes have a perturbatively infinite
ground state degeneracy associated with an infinite volume throat region of the
geometry. A simple argument based on causality is given that these states do
not have a description as ordinary massive particles in a low-energy effective
field theory. Pair production of magnetic black holes in a weak magnetic field
is estimated in a weakly-coupled semiclassical expansion about an instanton and
found to be finite, despite the infinite degeneracy of states. This suggests
that these states may store the information apparently lost in black hole
scattering processes.Comment: 16 pages, revision has 5 figures uuencode
Drained cyclic capacity of plate anchors in dense sand:Experimental and theoretical observations
This paper provides experimental evidence that shows that the drained cyclic capacity of a plate anchor in dry dense sand may be higher than the equivalent monotonic capacity. The experimental data show that when cyclic loading is low relative to the monotonic capacity, increases in the eventual capacity are observed; when the magnitudes of the cyclic loads are closer to the monotonic capacity, no increases in capacity are observed. These responses are explained in the paper using an elasto-plastic macro-element model extended with expandable bounding and memory surfaces that address the increase in strength or stiffness caused by changes in soil density and fabric when the anchor is subject to cyclic loading in dense sand. </jats:p
On the Boundary Dynamics of Chern-Simons Gravity
We study Chern-Simons theory with a complex G_C or a real G x G gauge group
on a manifold with boundary - this includes Lorentzian and Euclidean (anti-) de
Sitter (E/A)dS gravity for G=SU(2) or G=SL(2,R). We show that there is a
canonical choice of boundary conditions that leads to an unambiguous, fully
covariant and gauge invariant, off-shell derivation of the boundary action - a
G_C/G or G WZW model, coupled in a gauge invariant way to the boundary value of
the gauge field. In particular, for (E/A)dS gravity, the boundary action is a
WZW model with target space (E/A)dS_3, reminiscent of a worldsheet for
worldsheet mechanism. We discuss in some detail the properties of the boundary
theories that arise and we confront our results with various related
constructions in the literature.Comment: 22 pages, LaTeX2e, v2: JHEP3.cls, references and a footnote adde
Folds, Bosonization and non-triviality of the classical limit of 2D string theory
In the 1-dimensional matrix model one identifies the tachyon field in the
asymptotic region with a nonlocal transform of the density of fermions. But
there is a problem in relating the classical tachyon field with the surface
profile of the fermi fluid if a fold forms in the fermi surface. Besides the
collective field additional variables are required to describe folds.
In the quantum theory we show that the are the quantum dispersions of the
collective field. These dispersions become rather than
precisely after fold formation, thus giving additional `classical' quantities
and leading to a rather nontrivial classical limit. A coherent pulse reflecting
from the potential wall turns into high energy incoherent quanta (if a fold
forms), the frequency amplification being of the order of the square root of
the number of quanta in the incident wave.Comment: Latex, 12 page
- …
