Experimental Manipulation of Putative Selective Agents Provides Evidence for the Role of Natural Enemies in the Evolution of Plant Defense

Evolution ◽  
1997 ◽  
Vol 51 (5) ◽  
pp. 1435 ◽  
Author(s):  
Rodney Mauricio ◽  
Mark D. Rausher
Keyword(s):  
Plant Defense ◽  
Natural Enemies ◽  
Experimental Manipulation ◽  
Selective Agents

TESTING GOAL-DRIVEN CAPTURE BY THREAT

2019 ◽  
Author(s):  
Chris Robert Harrison Brown
Keyword(s):  
Experimental Evidence ◽  
Attentional Capture ◽  
Critical Role ◽  
Experimental Manipulation ◽  
Contingent Capture ◽  
Top Down ◽  
Affective Stimuli ◽  
Clinical Disorders ◽  
Positive Stimuli

Attention has long been characterised within prominent models as reflecting a competition between goal-driven and stimulus-driven processes. It remains unclear, however, how involuntary attentional capture by affective stimuli, such as threat-laden content, fits into such models. While such effects were traditionally held to reflect stimulus-driven processes, recent research has increasingly implicated a critical role of goal-driven processes. Here we test an alternative goal-driven account of involuntary attentional capture by threat, using an experimental manipulation of goal-driven attention. To this end we combined the classic ‘contingent capture’ and ‘emotion-induced blink’ (EIB) paradigms in an RSVP task with both positive or threatening target search goals. Across six experiments, positive and threat distractors were presented in peripheral, parafoveal, and central locations. Across all distractor locations, we found that involuntary attentional capture by irrelevant threatening distractors could be induced via the adoption of a search goal for a threatening category; adopting a goal for a positive category conversely led to capture only by positive stimuli. Our findings provide direct experimental evidence for a causal role of voluntary goals in involuntary capture by irrelevant threat stimuli, and hence demonstrate the plausibility of a top-down account of this phenomenon. We discuss the implications of these findings in relation to current cognitive models of attention and clinical disorders.

scholarly journals Arousing Motives or Eliciting Stories? On the Role of Pictures in a Picture–Story Exercise

Assessment ◽  
2021 ◽  
pp. 107319112110361
Author(s):  
Philipp Schäpers ◽  
Stefan Krumm ◽  
Filip Lievens ◽  
Nikola Stenzel
Keyword(s):  
Experimental Design ◽  
Experimental Manipulation ◽  
Implicit Motives ◽  
Achievement Motive ◽  
Picture Story Exercise ◽  
Power Motive ◽  
Picture Story ◽  
Measurement Approach

Picture–story exercises (PSE) form a popular measurement approach that has been widely used for the assessment of implicit motives. However, current theorizing offers two diverging perspectives on the role of pictures in PSEs: either to elicit stories or to arouse motives. In the current study, we tested these perspectives in an experimental design. We administered a PSE either with or without pictures. Results from N = 281 participants revealed that the experimental manipulation had a medium to large effect for the affiliation and power motive domains, but no effect for the achievement motive domain. We conclude that the herein chosen pictures cues function differentially across motives, as they aroused the affiliation and power motives, but not the achievement motive.

scholarly journals The experimental manipulation of atmospheric drought: Teasing out the role of microclimate in biodiversity experiments

2021 ◽  
Author(s):  
Beatriz A. Aguirre ◽  
Brian Hsieh ◽  
Samantha J. Watson ◽  
Alexandra J. Wright
Keyword(s):  
Experimental Manipulation

Role of plant defense in the utilization of native browse in southern Ethiopia

1995 ◽  
Vol 32 (2) ◽  
pp. 147-161 ◽  
Author(s):  
A. Woodward ◽  
D. L. Coppock
Keyword(s):  
Plant Defense ◽  
Southern Ethiopia

The role of temperature in microhabitat selection by northern water snakes (Nerodia sipedon)

1992 ◽  
Vol 70 (3) ◽  
pp. 417-422 ◽  
Author(s):  
Ian C. Robertson ◽  
Patrick J. Weatherhead
Keyword(s):  
Experimental Manipulation ◽  
Time Of Day ◽  
Microhabitat Selection ◽  
Nerodia Sipedon ◽  
Leopard Frogs ◽  
Water Snake ◽  
Northern Water Snakes ◽  
Water Snakes ◽  
Circadian Patterns

Using field observations and laboratory experiments we examined the role of temperature in microhabitat selection by an eastern Ontario population of northern water snakes (Nerodia sipedon). From 1349 random transects through a marsh we found that basking activity peaked at 09:00 and then declined steadily until 14:00 before increasing again. Our ability to detect snakes depended upon the microhabitat they occupied, and to the time of day when the snakes were encountered in water. In the field, temperatures of basking snakes averaged (±SE) 26.3 ± 0.7 °C (n = 36), while captive snakes in a thermal gradient showed a narrower selectivity, averaging 27.7 ± 0.4 °C (n = 21). The temperatures of basking snakes never exceeded 33 °C, even though a model snake placed in the sun reached 48 °C, suggesting that the snakes were thermoregulating to prevent overheating. In both the field and enclosures, water snakes basked more frequently as the temperature of the air increased relative to the water. Experimental manipulation of water temperature relative to air temperature revealed that temperature influenced microhabitat selection independently of circadian patterns. Finally, when in water, snakes tended to frequent habitats where leopard frogs (Rana pipiens), a common prey species, were most abundant, suggesting that prey distribution may also be an important component of water snake habitat selection.

Role of Oomycete Elicitors in Plant Defense Signaling

2019 ◽  
pp. 59-74
Author(s):  
Sudisha Jogaiah ◽  
Sharathchandra Ramasandra Govind ◽  
Huntrike Shekar Shetty
Keyword(s):  
Plant Defense ◽  
Defense Signaling ◽  
Plant Defense Signaling

scholarly journals Serotonin Receptors – From Molecular Biology to Clinical Applications

2011 ◽  
pp. 15-25 ◽  
Author(s):  
M. PYTLIAK ◽  
V. VARGOVÁ ◽  
V. MECHÍROVÁ ◽  
M. FELŠÖCI
Keyword(s):  
Pulmonary Hypertension ◽  
Serotonin Receptors ◽  
Clinical Applications ◽  
Panic Disorders ◽  
The Past ◽  
Complex Processes ◽  
Selective Agents ◽  
Different Populations ◽  
Irritable Bowel

Serotonin (5-hydroxytryptamine) is an ubiquitary monoamine acting as one of the neurotransmitters at synapses of nerve cells. Serotonin acts through several receptor types and subtypes. The profusion of 5-HT receptors should eventually allow a better understanding of the different and complex processes in which serotonin is involved. Its role is expected in the etiology of several diseases, including depression, schizophrenia, anxiety and panic disorders, migraine, hypertension, pulmonary hypertension, eating disorders, vomiting and irritable bowel syndromes. In the past 20 years, seven distinct families of 5-HT receptors have been identified and various subpopulations have been described for several of them. Increasing number of 5-HT receptors has made it difficult to unravel the role of 5-HT receptor subpopulations due to the lack of suitable selective agents. The present review describes the different populations and nomenclature of recently discovered 5-HT receptors and their pharmacological relevance.

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