Dynamics of Species and Size Structures of Phytoplankton at Different Levels of Bottom-Up and Top-Down Effects in Experimental Conditions

Ndi Umunyarwanda is a relatively new concept, having surfaced in post-genocide political narrative in July 2013. There is little doubt however that this concept currently dominates Rwandan identity politics and is envisioned as the answer to almost all the historical ills that have befallen and divided Rwanda. In light of the currently predominant discourse on post-genocide Rwanda, Ndi Umunyarwanda could be perceived as a top-down process of social engineering if considered only from the perspective of the current stage of its political dissemination. However, approached from its inception stage as this essay does, It is a bottom-up phenomenon that originates from Youth Connekt Dialogues (YCD); a series of dialogues held between children of perpetrators, children (of) survivors and representatives of local and central governments. The essay offers a narrative analysis of this emergence of Ndi Umunyarwanda out of YCD. The argument proposed here is that change in post-genocide Rwanda happens in different stages and at different levels. A narrative examination of YCD and Ndi Umunyarwanda as sequentially related phenomena shows that individual and group-initiated changes at grassroots levels can and do shape the national metanarrative of post-genocide nation building.

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Motion metaphors in discourse construction

Review of Cognitive Linguistics ◽

10.1075/rcl.9.1.06gar ◽

2011 ◽

Vol 9 (1) ◽

pp. 107-129

Author(s):

Joaquín Garrido

Keyword(s):

Cognitive Linguistics ◽

Relevance Theory ◽

Integrated Approach ◽

Top Down ◽

Bottom Up ◽

Discourse Representation Theory ◽

Prepositional Phrases ◽

Text Type ◽

Text Structures ◽

Different Levels

Motion metaphors occur at different levels, from prepositional phrases to discourse, including theoretical metaphors. After reviewing Relevance Theory as a bottom-up approach, and Cognitive Linguistics and Segmented Discourse Representation Theory as top-down ones, an integrated approach to metaphor in discourse construction is developed, based on a cognitive operation of connection of lower units into higher ones, similar to subsumption in the Lexical Constructional Model and to chunking in the Usage-Based Approach. In discourse construction, as the analysis of press and poetry examples show, either a motion metaphor may contribute to the discourse structure, or it may result from it. Discourses are packed into text structures; live discourse metaphors develop into text-type metaphors on their way to conventionalization. Metaphor and discourse construction are bottom-up processes, since they result from connection of lower units, but they are also top-down, based on properties of higher units, domains in metaphor and relations in discourse.

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Neural markers of predictive coding under perceptual uncertainty revealed with Hierarchical Frequency Tagging

eLife ◽

10.7554/elife.22749 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 32

Author(s):

Noam Gordon ◽

Roger Koenig-Robert ◽

Naotsugu Tsuchiya ◽

Jeroen JA van Boxtel ◽

Jakob Hohwy

Keyword(s):

Sensory Input ◽

Predictive Coding ◽

Signal Integration ◽

Top Down ◽

Bottom Up ◽

Visual Hierarchy ◽

Neural Markers ◽

Different Levels

There is a growing understanding that both top-down and bottom-up signals underlie perception. But it is not known how these signals integrate with each other and how this depends on the perceived stimuli’s predictability. ‘Predictive coding’ theories describe this integration in terms of how well top-down predictions fit with bottom-up sensory input. Identifying neural markers for such signal integration is therefore essential for the study of perception and predictive coding theories. To achieve this, we combined EEG methods that preferentially tag different levels in the visual hierarchy. Importantly, we examined intermodulation components as a measure of integration between these signals. Our results link the different signals to core aspects of predictive coding, and suggest that top-down predictions indeed integrate with bottom-up signals in a manner that is modulated by the predictability of the sensory input, providing evidence for predictive coding and opening new avenues to studying such interactions in perception.

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The Effectiveness of Human Rights

Reframing Human Rights in a Turbulent Era ◽

10.1093/oso/9780198299578.003.0002 ◽

2021 ◽

pp. 9-48

Author(s):

Gráinne de Búrca

Keyword(s):

Human Rights ◽

International Human Rights Law ◽

Human Rights Law ◽

Crucial Importance ◽

Top Down ◽

International Human Rights ◽

Bottom Up ◽

External Intervention ◽

Different Levels ◽

Multiple Actors

This chapter surveys existing theories of the effectiveness of human rights, and notes that several prominent accounts have adopted either a ‘top down’ or a ‘bottom up’ theory of effectiveness, emphasizing either external intervention or grassroots mobilization as the primary motor of change. The experimentalist theory advanced in this chapter and throughout the book, however, argues that the effectiveness of much human rights law and advocacy comes neither primarily from top-down intervention nor primarily from bottom-up action but through the iterative interaction between multiple actors, norms and institutions situated at different levels within and outside the state. Building on an emerging scholarship from political scientists, anthropologists, and human rights practitioners, the chapter advances an experimentalist account of international human rights law and advocacy, and introduces the three case studies of human rights campaigns which will be discussed in subsequent chapters. The experimentalist account emphasizes the crucial importance of social mobilization and civil society activism, but argues that the interaction of domestic activism with international accountability institutions is particularly effective in promoting human rights.

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FROM IMAGE FEATURES TO SYMBOLS AND VICE VERSA — USING GRAPHS TO LOOP DATA- AND MODEL-DRIVEN PROCESSING IN VISUAL ASSEMBLY RECOGNITION

International Journal of Pattern Recognition and Artificial Intelligence ◽

10.1142/s0218001404003198 ◽

2004 ◽

Vol 18 (03) ◽

pp. 497-517 ◽

Cited By ~ 7

Author(s):

CHRISTIAN BAUCKHAGE ◽

ELKE BRAUN ◽

GERHARD SAGERER

Keyword(s):

Knowledge Representation ◽

Graph Matching ◽

Image Features ◽

Top Down ◽

Object Knowledge ◽

Levels Of Abstraction ◽

Bottom Up ◽

Model Driven ◽

Knowledge Propagation ◽

Different Levels

Graphs and graph matching are powerful mechanisms for knowledge representation, pattern recognition and machine learning. Especially in computer vision their application is manifold. Graphs can characterize relations among image features like points or regions but they may also represent symbolic object knowledge. Hence, graph matching can accomplish recognition tasks on different levels of abstraction. In this contribution, we demonstrate that graphs may also bridge the gap between different levels of knowledge representation. We present a system for visual assembly monitoring that integrates bottom-up and top-down strategies for recognition and automatically generates and learns graph models to recognize assembled objects. Data-driven processing is subdived into three stages: first, elementary objects are recognized from low-level image features. Then, clusters of elementary objects are analyzed syntactically; if an assembly structure is found, it is translated into a graph that uniquely models the assembly. Finally, symbolic models like this are stored in a database so that individual assemblies can be recognized by means of graph matching. At the same time, these graphs enable top-down knowledge propagation: they are transformed into graphs which represent relations between image features and thus describe the visual appearance of the recently found assembly. Therefore, due to model-driven knowledge propagation assemblies may subsequently be recognized from graph matching on a lower computational level and tedious bottom-up processing becomes superfluous.

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