Embedding interactive innovation approaches in the top-down agricultural research and extension system of Ethiopia : Insights of Tigray

Abstract Food security interventions and policies need reliable estimates of actual crop production and the scope to enhance production on existing cropland. We assess the performance of two widely used “top-down” gridded frameworks (GAEZ and AgMIP) versus an alternative “bottom-up” approach that estimates extra production potential locally, for a number of representative sites, and then upscales the results to larger spatial scales (GYGA). Our results show that estimates from top-down frameworks are alarmingly unlikely, with estimated potential production being lower than current production at some locations. The consequences of using these coarse estimates to predict food security are illustrated by an example from sub-Saharan Africa. Our study shows that current foresights on food security, land use, and climate change and associate priority setting on AR&D based on yield potential and yield gaps derived from top-down approaches are subject to a high degree of uncertainty and would benefit from incorporating estimates from bottom-up approaches.

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Meeting the challenges to agricultural research and extension

American Journal of Alternative Agriculture ◽

10.1017/s0889189300003684 ◽

1990 ◽

Vol 5 (4) ◽

pp. 184-187 ◽

Cited By ~ 2

Author(s):

Richard Sauer

Keyword(s):

Agricultural Production ◽

Agricultural Research ◽

Research Center ◽

Conventional Agriculture ◽

The Public ◽

Alternative Technologies ◽

Extension System ◽

Alternative Systems ◽

Public Agricultural Research

AbstractThe public agricultural research and extension system has provided the foundation for great improvements in U.S. agricultural production. However, our incomparable productivity has brought with it serious problems. These problems have also led to a rapidly changing perception about both agricultural scientists and today's conventional agriculture. Critics are placing high on the agenda of the agricultural research and extension establishment the need for alternative technologies that are more sustainable and less exploitative of our resources. The growing demand for alternative systems offers challenges for every part of the establishment-research and extension administrators, branch station/research center directors, and faculty. These challenges and how they should be met are discussed. Alternative systems will become the conventional agriculture of tomorrow.

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Top-Down Processing and Visual Reorientation Illusions in a Virtual Reality Environment

Swiss Journal of Psychology ◽

10.1024/1421-0185.63.3.143 ◽

2004 ◽

Vol 63 (3) ◽

pp. 143-149 ◽

Cited By ~ 3

Author(s):

Fred W. Mast ◽

Charles M. Oman

Keyword(s):

Virtual Reality ◽

Visual Processing ◽

Line Length ◽

Perceptual Cues ◽

Virtual Reality Environment ◽

Top Down ◽

Test Conditions ◽

The Subject ◽

Processing Mechanisms

The role of top-down processing on the horizontal-vertical line length illusion was examined by means of an ambiguous room with dual visual verticals. In one of the test conditions, the subjects were cued to one of the two verticals and were instructed to cognitively reassign the apparent vertical to the cued orientation. When they have mentally adjusted their perception, two lines in a plus sign configuration appeared and the subjects had to evaluate which line was longer. The results showed that the line length appeared longer when it was aligned with the direction of the vertical currently perceived by the subject. This study provides a demonstration that top-down processing influences lower level visual processing mechanisms. In another test condition, the subjects had all perceptual cues available and the influence was even stronger.

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Functional Anatomy of Intensity Aspects of Attention

Zeitschrift für Neuropsychologie ◽

10.1024/1016-264x.14.3.181 ◽

2003 ◽

Vol 14 (3) ◽

pp. 181-190 ◽

Cited By ~ 2

Author(s):

Walter Sturm

Keyword(s):

Right Hemisphere ◽

Functional Anatomy ◽

Fmri Data ◽

Functional Networks ◽

Top Down ◽

Stimulus Modality ◽

Spatial Orienting ◽

Phasic Alertness ◽

Co Activation ◽

Attention System

Abstract: Behavioral and PET/fMRI-data are presented to delineate the functional networks subserving alertness, sustained attention, and vigilance as different aspects of attention intensity. The data suggest that a mostly right-hemisphere frontal, parietal, thalamic, and brainstem network plays an important role in the regulation of attention intensity, irrespective of stimulus modality. Under conditions of phasic alertness there is less right frontal activation reflecting a diminished need for top-down regulation with phasic extrinsic stimulation. Furthermore, a high overlap between the functional networks for alerting and spatial orienting of attention is demonstrated. These findings support the hypothesis of a co-activation of the posterior attention system involved in spatial orienting by the anterior alerting network. Possible implications of these findings for the therapy of neglect are proposed.

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