86,591 research outputs found
Bilateral organization of the vocal control pathway in the budgerigar, Melopsittacus undulatus
No full textAnatomical and electrophysiological methods were used to map the vocal control nuclei of the budgerigar, Melopsittacus undulatus. Beginning with the motor nucleus of the syrinx, nuclei were located using antidromic stimulation and then injected with horseradish peroxidase (HRP). Retrogradely transported HRP labeled afferents to the injected nucleus. This procedure was repeated at successively higher levels along the vocal pathway. Connections found using this strategy then were confirmed using anterograde transport of HRP and/or tritiated proline and orthodromic electrical stimulation. We found that the primary vocal control pathway consisted of (1) the motor nucleus innervating the trachea and syrinx, nXIIts; (2) an archistriatal nucleus, RA; and (3) a neostriatal nucleus, “HVc.” These nuclei correspond to similar, possibly homologous, nuclei in the vocal control pathway of the canary (Nottebohm, F., T. M. Stokes, and C. M. Leonard (1976) J. Comp. Neurol. 165: 457–486) but, because of differences in gross brain morphology, are displaced considerably in absolute position. Furthermore, the projection from RA to the motor nucleus is bilateral in the budgerigar, whereas the same connection is strictly ipsilateral in the canary. The projection of the motor nucleus to muscles of the vocal organ is also bilateral in the budgerigar (Manogue, K. R., and F. Nottebohm (1981) J. Compl. Neurol., in press) but ipsilateral in the canary. the possible significance of these species differences for lateralization of motor control is discussed.</jats:p
Chronik der Königlichen Gewerbe-Akademie zu Berlin
No full textCHRONIK DER KÖNIGLICHEN GEWERBE-AKADEMIE ZU BERLIN
Chronik der Königlichen Gewerbe-Akademie zu Berlin / Nottebohm, Friedrich Wilhelm (Public Domain) ( - )
Title page ( - )
Preface ( - )
Erste Periode. 1821 - 1845 (1)
Zweite Periode. 1845 - 1857 ([23])
Dritte Periode. 1857 - 1871 ([35])
Chronik des Grundstückes der Königlichen Gewerbe-Akademie ([53])
Schlusswort ([61])
Anlage A. An des Königs Majestät ([63])
Anlage B ([65])
Anlage C. An des Königs Majestät ([66])
Anlage D ([68])
Anlage E. Zusammenstellung der Directoren, Lehrer und Privat-Docenten der Königlichen Gewerbe-Akademie von der Gründung der Anstalt am 1. November 1821 bis dahin 1871 ([69])
Anlage F. Nachweisung der Frequenz der Königlichen Gewerbe-Akademie von der Gründung der Anstalt im Jahr 1821 bis 1871 ([79])
Imprint (83)
Anlage G. Frequenz-Skala der Königlichen Gewerbe-Akademie 1821 bis 1871 ( -
Modification of synapses in androgen-sensitive muscle. I. Hormonal regulation of acetylcholine receptor number in the songbird syrinx
No full textThe songbird syrinx is sexually dimorphic and responds to changes in blood testosterone levels with changes in muscle size and in activity of cholinergic enzymes (Luine, V., F. Nottebohm, C. Harding, and B.S. McEwen (1980) Brain Res. 192: 89–107). Here, we demonstrate that there is a sex difference in the number of acetylcholine receptors (AChRs) in the syrinx and that alterations in the levels of circulating testosterone can cause changes in AChR number in syringeal muscles. These results suggest that the size or number of endplates in the syringeal muscles may be increased by circulating testosterone. The time course of these effects was examined after increases in blood testosterone in females and decreases in males. We also examined the effect of increased testosterone in syrinx isolated from neural influences by denervation and found that denervated muscle responded to testosterone with an increase in acetylcholinesterase activity but not with increases in protein content or AChR number.</jats:p
Mapping of radial glia and of a new cell type in adult canary brain
No full textFrontal and coronal sections of adult male and female canary brain were stained with a monoclonal antibody to vimentin using an immunoperoxidase technique; some sections were counterstained with cresyl violet. The position of radial glia cells was mapped using a computer-linked microscope. The telencephalon was found to have a rich set of radial glia. The long processes of these radial glia showed a mediolateral orientation, and were much more abundant in some parts of the telencephalon (e.g., hyperstriatum, caudal neostriatum, and lobus parolfactorius) than in others (e.g., anterior neostriatum, archistriatum, and septum), which had few or no radial glia fibers. A small, elongated cell type not previously described in adult avian brain was frequently seen to be associated with the long processes of the radial glia, oriented in the same direction and often in close apposition. The position of these cells was also systematically mapped, and they were found to be virtually absent outside of the telencephalon. The relation between radial glia fibers and the small, elongated cells was most commonly seen close to the lateral ventricle of the forebrain, where the radial glia cells have their cell bodies. The above observations suggest that there may be a functional relation between radial glia and the small, elongated cells. We hypothesize that the latter cells are young migrating neurons. This hypothesis is tested in a separate publication (A. Alvarez-Buylla and F. Nottebohm, unpublished observations).</jats:p
Direct evidence for loss and replacement of projection neurons in adult canary brain
No full textNormally occurring projection neuron loss and replacement were quantified over a 6 month period in the pathway from the high vocal center (HVC) to the robust nucleus of the archistriatum (RA) in adult male canaries. Fluorescent latex microspheres were injected into RA in April--a procedure resulting in long-term retrograde labeling of RA- projecting HVC neurons. Labeled cell densities were then obtained 4 and 20 d later in April and 195 d later in October. We found that 41–49% of the RA-projecting HVC neurons present the previous April were no longer present in October. Fluorogold injections in RA 3 d prior to death in April and October retrogradely labeled similar overall densities of RA- projecting HVC neurons, indicating that cells lost over this 6 month period were replaced by new RA-projecting HVC neurons. Newer cells were larger than older cells, suggesting that an age-dependent reduction in size might precede death. Over the same time interval, no loss was observed for neurons projecting from the lateral magnocellular nucleus of the anterior neostriatum to RA. Thus, loss was specific to the input from HVC to RA. These findings raise the possibility that much if not all of the pathway from HVC to RA is replaced within a year. The time period examined encompasses the yearly transition from stable song to song learning in the canary (Nottebohm et al., 1986, 1987). A pronounced loss and replacement of neurons implicated in vocal control during this period may relate to the canary's ability to modify song in adulthood.</jats:p
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
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
- …
