The Role of Prior Message Context in Evaluative Judgments of High- and Low-Diversity Messages

1977 ◽  
Vol 20 (4) ◽  
pp. 295-307 ◽  
Author(s):  
James J. Bradac ◽  
Robert A. Davies ◽  
John A. Courtright
Keyword(s):  
Evaluative Judgments ◽  
Low Diversity

Assessing the Role of Contingency Awareness in Attitudinal Conditioning with Implications for Advertising Research

1989 ◽  
Vol 26 (1) ◽  
pp. 30-43 ◽  
Author(s):  
Chris T. Allen ◽  
Chris A. Janiszewski
Keyword(s):  
Cognitive Processes ◽  
Theory Development ◽  
Basic Mechanism ◽  
Contingency Learning ◽  
Television Commercials ◽  
Conditioning Procedure ◽  
Contingency Awareness ◽  
Evaluative Judgments ◽  
Post Hoc

The authors investigate a basic mechanism for shaping attitudes that has largely been ignored by empirical researchers in the marketing discipline. Two experiments are reported in which traditional Pavlovian procedures are merged with a view of conditioning that encourages theorizing about attendant cognitive processes. The data indicate that contingency learning or awareness may be a requirement for successful attitudinal conditioning. Contingency awareness entails conscious recognition of the relational pattern between the conditioned and unconditioned stimuli used in a conditioning procedure. In experiment 1, the conditioning procedure affected the evaluative judgments of subjects who were classified ( post hoc) as contingency aware. In experiment 2, instructions that promoted contingency learning as part of the procedure again influenced participants’ attitude judgments. Implications are offered for theory development and for constructing advertisements to foster attitudinal conditioning. Specific suggestions for further research on how one might structure television commercials to foster contingency learning also are presented.

The Role of Fire in Natural Communities: An Example from the Southern Sierra Nevada, California

1976 ◽  
Vol 3 (2) ◽  
pp. 91-99 ◽  
Author(s):  
David J. Parsons
Keyword(s):  
Sierra Nevada ◽  
Woody Species ◽  
Past Century ◽  
The Past ◽  
Shrub Community ◽  
Healthy State ◽  
Low Diversity ◽  
Vegetational Succession ◽  
Dead Material

The exclusion of fire from the low-elevation foothills of the southern Sierra Nevada of California over the past century has resulted in large expanses of over-mature, senescent chaparral. The fuel buildup associated with this situation poses a threat, in that any fire which gets started has the potential of becoming a major holocaust.A detailed analysis is made of the vegetational succession following fire in four different-aged stands of Chamise chaparral in the southern Sierra Nevada. Progression from a diverse multi-species herb and shrub community towards a dense, structurally uniform, low-diversity stand dominated by a single woody species, Adenostoma fasciculatum (Chamise), is demonstrated. An increase in shrub cover and height along with the amount of dead material found laddered through the canopy, create optimal conditions for combustion within some 35 years following the last fire. The herbaceous vegetation shows a high diversity and cover in the first few years after burning, but rapidly decreases thereafter. Evidence is presented that frequent fires are required to maintain the chaparral community in a vigorous and healthy state. The need to institute progressive fuel-management programmes which recognize the natural role of fire in the evolution of the chaparral type wherever it is found, is discussed and advocated. Attempts are also made to relate these findings to the preservation of other fire-adapted vegetation types of the world.

scholarly journals The Discussion Goes on: What Is the Role ofEuryarchaeotain Humans?

Archaea ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
H.-P. Horz ◽  
G. Conrads
Keyword(s):  
Experimental Data ◽  
Scientific Community ◽  
Intestinal Tract ◽  
Bacterial Species ◽  
Methanogenic Archaea ◽  
Archaeal Species ◽  
Methanosphaera Stadtmanae ◽  
Low Diversity ◽  
Health And Disease

The human body (primarily the intestinal tract, the oral cavity, and the skin) harbours approximately 1,000 different bacterial species. However, the number of archaeal species known to colonize man seems to be confined to a handful of organisms within the classEuryarchaeota(includingMethanobrevibacter smithii,M. oralis, andMethanosphaera stadtmanae). In contrast to this conspicuously low diversity ofArchaeain humans their unique physiology in conjunction with the growing number of reports regarding their occurrence at sites of infection has made this issue an emerging field of study. While previous review articles in recent years have addressed the putative role of particularly methanogenic archaea for human health and disease, this paper compiles novel experimental data that have been reported since then. The aim of this paper is to inspire the scientific community of “Archaeaexperts” for those unique archaeal organisms that have successfully participated in the human-microbe coevolution.

Integrating Compositional and Decompositional Analyses to Represent the Intervening Role of Perceptions in Evaluative Judgments

1981 ◽  
Vol 18 (1) ◽  
pp. 13-28 ◽  
Author(s):  
Morris B. Holbrook
Keyword(s):  
Conjoint Analysis ◽  
Integrative Approach ◽  
Stage Model ◽  
Evaluative Judgment ◽  
Evaluative Judgments ◽  
Product Features ◽  
Decompositional Analysis ◽  
Relationship Of ◽  
Aesthetic Preferences

In the study of preference formation, compositional methods (e.g., linear compensatory attitude models) and decompositional techniques (e.g., conjoint analysis) have developed along relatively separate paths. The author attempts to integrate these two approaches via a two-stage model of evaluative judgment whose testing incorporates aspects of both analytic procedures. Specifically, the overall effect of objective product features on affect is broken down into a compositional relationship of affect to perceptions (i.e., attitude structure) and a decompositional analysis of the dependence of perceptions on product features (i.e., psychophysical relations). The approach is illustrated by a study of aesthetic preferences among piano performances differing in four factorially arrayed musical features (tempo, rhythm, dynamics, and phrasing). An integration of decompositional and compositional methods generates a summary path-analytic diagram that clearly represents the process wherein objective product features shape perceptions which, in turn, determine affect. This integrative approach appears to be applicable in several marketing contexts.

scholarly journals Strong selective sweeps on the X chromosome in the human-chimpanzee ancestor explain its low divergence

2014 ◽  
Author(s):  
Julien Y Dutheil ◽  
Kasper Munch ◽  
Kiwoong Nam ◽  
Thomas Mailund ◽  
Mikkel Schierup
Keyword(s):  
X Chromosome ◽  
Incomplete Lineage Sorting ◽  
Underlying Mechanism ◽  
Selective Sweeps ◽  
Lineage Sorting ◽  
X Chromosomes ◽  
Unique Role ◽  
Ancestral Species ◽  
Low Diversity

The human and chimpanzee X chromosomes are less divergent than expected based on autosomal divergence. This has led to a controversial hypothesis proposing a unique role of the X chromosome in human-chimpanzee speciation. We study incomplete lineage sorting patterns between humans, chimpanzees and gorillas to show that this low divergence is entirely due to megabase-sized regions comprising one-third of the X chromosome, where polymorphism in the human-chimpanzee ancestral species was severely reduced. Background selection can explain 10% of this reduction at most. Instead, we show that several strong selective sweeps in the ancestral species can explain this reduction of diversity in the ancestor. We also report evidence of population specific sweeps in extant humans that overlap the regions of low diversity in the ancestral species. These regions further correspond to chromosomal sections shown to be devoid of Neanderthal introgression into modern humans. This suggests that the same X-linked regions that undergo selective sweeps are among the first to form reproductive barriers between diverging species. We hypothesize that meiotic drive is the underlying mechanism causing these two observations.

Role of photosymbiosis and biogeography in the diversification of early Paleogene acarininids (planktonic foraminifera)

Paleobiology ◽  
2001 ◽  
Vol 27 (2) ◽  
pp. 311-326 ◽  
Author(s):  
Frédéric Quillévéré ◽  
Richard. D. Norris ◽  
Issam Moussa ◽  
William. A. Berggren
Keyword(s):  
High Latitude ◽  
Planktonic Foraminifera ◽  
Evolutionary Diversification ◽  
Tropical Environments ◽  
Low Latitudes ◽  
Low Diversity ◽  
Close Relationship ◽  
The Tropics ◽  
Early Paleogene

Radiations are commonly believed to be linked to the evolutionary appearance of a novel morphology or ecology. Previous studies have demonstrated a close relationship between the evolutionary appearance of algal photosymbiosis in planktonic foraminifera and evolutionary diversification of Paleogene photosymbiotic clades. For example, the evolution of photosymbiosis was synchronous with the abrupt evolution of four major groups of Paleogene planktonic foraminifera including two clades within the genus Morozovella, as well as the genera Acarinina and Igorina. Our new isotopic and biogeographic data suggest that the acarininids evolved from a photosymbiotic ancestor (which we identify as Praemurica inconstans or early representatives of Praemurica uncinata), but also demonstrate that photosymbiosis did not trigger an immediate species-level radiation in this group. Instead, the acarininids remained a low-diversity taxon restricted to high latitudes for nearly 1.8 million years before radiating ecologically and taxonomically. The eventual radiation of the acarininids is tied to an expansion of their geographic range into the mid and low latitudes. Biogeographic analyses of modern plankton suggest that high-latitude environments may be less conducive to establishing radiations simply because there are fewer niches available to be filled than there are in the tropics. Accordingly, the acarininids may have initially failed to diversify because they started off in environments that presented few opportunities to sustain a large radiation. The high-latitude origin of the acarininids continued to retard their overall diversification until they were able to develop strategies that allowed them to expand into tropical environments and fully exploit their photosymbiotic ecology.

Species richness, relative abundance and dwarfism in Azorean bivalves: consequences of latitude, isolation or productivity? Or all three?

2013 ◽  
Vol 94 (3) ◽  
pp. 567-578 ◽  
Author(s):  
Brian Morton ◽  
Regina Tristão Da Cunha ◽  
António M. De Frias Martins
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Nutrient Deficiency ◽  
Maximum Size ◽  
Bivalve Species ◽  
Population Densities ◽  
Large Numbers ◽  
Low Diversity ◽  
Population Sizes

The Azorean seabed is depauperate in terms of bivalve species richness, there being only between ~70 and 80 recorded to date, most being sub-tidal and generally lacking of specialists. Analysis of large numbers (>3200) of Azorean bivalve shells has revealed that, overall, each species is only ~50% the shell length size of Mediterranean conspecifics. Thus, although Azorean bivalve size may be a consequence of decreasing latitude (Bergmann's Rule), the islands are located at approximately the same latitude as the Mediterranean (and are influenced by those waters) where larger conspecifics occur. Hence, the main reason for bivalve dwarfism in the archipelago appears to result from low oceanic productivity (Foster's Rule). This, in turn, is associated with low diversity, possibly resulting from past extinctions and isolation, and low population sizes, except for Ervilia castanea, which here overwhelmingly occupies higher-energy inshore habitats and associated higher productivities. Nevertheless, this species too is dwarfed by mainland conspecifics. Similarly, the introduced Venerupis decussata, found solely within the lagoonal environment of Fajã de Santo Cristo on São Jorge, is somewhat smaller than its mainland conspecifics, although it is abundant enough to warrant artisanal exploitation. This study therefore, supports Foster's Rule and argues for the role of nutrient deficiency in regulating Azorean species richness and individual maximum size. In waters of locally higher productivities, however, population densities increase, but not size.

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