Modulation of orientation-selective neurons by motion: when additive, when multiplicative?

The recurrent interaction among orientation-selective neurons in the primary visual cortex (V1) is suited to enhance contours in a noisy visual scene. Motion is known to have a strong pop-up effect in perceiving contours, but how motion-sensitive neurons in V1 support contour detection remains vastly elusive. Here we suggest how the various types of motion-sensitive neurons observed in V1 should be wired together in a micro-circuitry to optimally extract contours in the visual scene. Motion-sensitive neurons can be selective about the direction of motion occurring at some spot or respond equally to all directions (pandirectional). We show that, in the light of figure-ground segregation, direction-selective motion neurons should additively modulate the corresponding orientation-selective neurons with preferred orientation orthogonal to the motion direction. In turn, to maximally enhance contours, pandirectional motion neurons should multiplicatively modulate all orientation-selective neurons with co-localized receptive fields. This multiplicative modulation amplifies the local V1-circuitry among co-aligned orientation-selective neurons for detecting elongated contours. We suggest that the additive modulation by direction-specific motion neurons is achieved through synaptic projections to the somatic region, and the multiplicative modulation by pandirectional motion neurons through projections to the apical region of orientation-specific pyramidal neurons. For the purpose of contour detection, the V1-intrinsic integration of motion information is advantageous over a downstream integration as it exploits the recurrent V1-circuitry designed for that task.

The history of the hebrew nation : from its first origin to the present time

by J. W. Brooks

Zusatz zu den Vorschlägen und Mitteln über die bürgerliche Cultur und Religionsaufklärung der jüdischen Nation, mit einigen Nachrichten von Juden in Polen und den rußischen Provinzen

[Gottlieb Schlegel]

Ueber das Verhältniß der jüdischen Nation zum christlichen Bürgervereine

von C. F. v. Schmidt-Phiseldek

Worte der Wahrheit und des Friedens an die gesammte jüdische Nation : vorzüglich an diejenigen, so unter dem Schutze des glorreichen und großmächtigsten Kaysers Josephs II. wohnen

[Naphtali Herz Wessely.] Aus dem Hebr. [von David Friedländer]

Über das jetzige Verhältnis der Jüdischen Nation zu dem christlichen Bürgervereine, und dessen künftige Umgestaltung : 2 Abhandlungen

von C. F. von Schmidt-Phiseldek

Die Christen unter den Juden, oder: Wie würde es den Christen gehen, wenn die Juden die herrschende Nation wären? : Ein Seitenstück zu d. Schrift: "Die Juden unter d. Christen" ; nebst e. Schreiben an d. Herrn Pfarrer Oertel zu Markt-Lenkersheim

von Hermann Stern

Das Ende des Antisemitismus : ein Friedensgruss an die deutsche Nation

von Felix Herrmann

Quantitative morphometric analysis of lakes using GIS: rectangularity R , ellipticity E , orientation O , and the rectangularity vs. ellipticity index, REi

Quantitative measures of polygon shapes and orientation are important elements of geospatial analysis. These kinds of measures are particularly valuable in the case of lakes, where shape and orientation patterns can help identifying the geomorphological agents behind lake formation and evolution. However, the lack of built-in tools in commercial geographic information system (GIS) software packages designed for this kind of analysis has meant that many researchers often must rely on tools and workarounds that are not always accurate. Here, an easy-to-use method to measure rectangularity R, ellipticity E, and orientation O is developed. In addition, a new rectangularity vs. ellipticity index, REi, is defined. Following a step-by-step process, it is shown how these measures and index can be easily calculated using a combination of GIS built-in functions. The identification of shapes and estimation of orientations performed by this method is applied to the case study of the geometric and oriented lakes of the Llanos de Moxos, in the Bolivian Amazon, where shape and orientation have been the two most important elements studied to infer possible formation mechanisms. It is shown that, thanks to these new indexes, shape and orientation patterns are unveiled, which would have been hard to identify otherwise.

Einige Worte über den neuerlichen Vorschlag der unbedigten Gleichberechtigung der Juden : zugleich Entgegung auf d. Anklagen, womit d. heutigen Verfechter d. Juden-Emancipation gegen d. poln. Nation auftreten

geschrieben von Heinrich Schmitt

Die Judenfrage gegenüber dem deutschen Handel und Gewerbe : ein Manifest an die deutsche Nation

von Egon Waldegg [d.i. Alexander Pinkert]