Experimental Studies on the Nature of Species. I. Effect of Varied Environments on Western North American Plants.Jens Clausen , David D. Keck , William M. Hiesey

1941 ◽  
Vol 75 (756) ◽  
pp. 74-79 ◽  
Author(s):  
Carl L. Hubbs
Keyword(s):  
North American ◽  
Experimental Studies

scholarly journals Brazilian norms for the International Affective Picture System (IAPS): comparison of the affective ratings for new stimuli between Brazilian and North-American subjects

2008 ◽  
Vol 57 (4) ◽  
pp. 270-275 ◽  
Author(s):  
Cristina Lasaitis ◽  
Rafaela Larsen Ribeiro ◽  
Orlando Francisco Amodeo Bueno
Keyword(s):  
North American ◽  
Experimental Studies ◽  
International Affective Picture System ◽  
The Self ◽  
Self Assessment ◽  
North Americans ◽  
The North ◽  
Reliable Instrument ◽  
Student’S T ◽  
Normative Ratings

OBJECTIVE: The study presents the Brazilian norms for 240 new stimuli from International Affective Picture System (IAPS), a database of affective images widely used in research, compared to the North-American normative ratings. METHODS: The participants were 448 Brazilian university students from several courses (269 women and 179 men) with mean age of 24.2 (SD = 7.8), that evaluated the IAPS pictures in the valence, arousal and dominance dimensions by the Self-Assessment Manikin (SAM) scales. Data were compared across the populations by Pearson linear correlation and Student's t-tests. RESULTS: Correlations were highly significant for all dimensions; however, Brazilians' averages for arousal were higher than North-Americans'. CONCLUSIONS: The results show stability in relation to the first part of the Brazilian standardization and they are also consistent with the North-American standards, despite minor differences relating to interpretation of the arousal dimension, demonstrating that IAPS is a reliable instrument for experimental studies in the Brazilian population.

scholarly journals Glucocorticoids coordinate changes in gut microbiome composition in wild North American red squirrels

2021 ◽  
Author(s):  
Lauren Petrullo ◽  
Tiantian Ren ◽  
Martin Wu ◽  
Rudy Boonstra ◽  
Rupert Palme ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
North American ◽  
Gut Microbiome ◽  
Pathogenic Bacteria ◽  
Experimental Studies ◽  
Ecological Framework ◽  
Ecological Change ◽  
Red Squirrels ◽  
Microbiome Diversity ◽  
North American Red Squirrels

Gut microbiome diversity plays an important role in host health and fitness, in part through the diversification of gut metabolic function and pathogen protection. Elevations in glucocorticoids (GCs) appear to reduce gut microbiome diversity in experimental studies, suggesting that a loss of microbial diversity may be a negative consequence of increased GCs. However, given that ecological factors like food availability and population density may independently influence both GCs and microbial diversity, understanding how these factors structure the GC-microbiome relationship is crucial to interpreting its significance in wild populations. Here, we used an ecological framework to investigate the relationship between GCs and gut microbiome diversity in wild North American red squirrels (Tamiasciurus hudsonicus). We found that higher GCs predicted lower gut microbiome diversity and an increase in metabolic taxa. In addition, we identified a loss of potentially pathogenic bacteria with increasing GCs. Both dietary heterogeneity and an upcoming masting event exhibited direct effects on gut microbiome diversity, whereas conspecific density and host reproductive activity impacted diversity indirectly via changes in GCs. Together, our results suggest that GCs coordinate the effects of ecological change and host biology on gut microbiome diversity, and highlight the importance of situating the GC-microbiome relationship within an ecological framework.

scholarly journals Community-Engaged Research Builds a Nature-Culture of Hope on North American Great Plains Rangelands

2019 ◽  
Vol 8 (1) ◽  
pp. 22 ◽  
Author(s):  
Hailey Wilmer ◽  
Lauren Porensky ◽  
María Fernández-Giménez ◽  
Justin Derner ◽  
David Augustine ◽  
...  
Keyword(s):  
Great Plains ◽  
North American ◽  
Research Effort ◽  
Experimental Studies ◽  
Rangeland Management ◽  
Specific Information ◽  
Team Members ◽  
Community Engaged Research ◽  
The North ◽  
Effective Community

In the North American Great Plains, multigenerational ranches and grassland biodiversity are threatened by dynamic and uncertain climatic, economic, and land use processes. Working apart, agricultural and conservation communities face doubtful prospects of reaching their individual goals of sustainability. Rangeland research could serve a convening platform, but experimental studies seldom involve local manager communities. The Collaborative Adaptive Rangeland Management (CARM) project, however, has undertaken a ten-year, ranch-level, participatory research effort to explore how community-engaged research can increase our understanding of conservation and ranching goals. Using ethnographic data and the nature-culture concept—which recognizes the inseparability of ecological relationships that are shaped by both biological and social processes—we examine the CARM team’s process of revising their management objectives (2016–2018). In CARM’s early days, the team established locally-relevant multifunctional goals and objectives. As team members’ understanding of the ecosystem improved, they revised objectives using more spatially, temporally and ecologically specific information. During the revision process, they challenged conventional ecological theories and grappled with barriers to success outside of their control. The emerging CARM nature-culture, based on a sense of place and grounded in hope, provides insights into effective community-engaged research to enhance rangeland livelihood and conservation outcomes.

scholarly journals Experimental Studies of Mimicry in some North American Butterflies

Nature ◽  
1957 ◽  
Vol 180 (4583) ◽  
pp. 444-444 ◽  
Author(s):  
JANE VAN ZANDT BROWER
Keyword(s):  
North American ◽  
Experimental Studies

Mass Harvesting, Ichthyofaunal Assemblages, and Ancestral Paiute Fishing in the North American Great Basin

2020 ◽  
Vol 85 (4) ◽  
pp. 715-736
Author(s):  
B. Sunday Eiselt
Keyword(s):  
Great Basin ◽  
North American ◽  
Fish Assemblages ◽  
Experimental Studies ◽  
Investment Model ◽  
Technology Investment ◽  
The North ◽  
Middle Range ◽  
Mean Size ◽  
Tui Chub

Documenting variability in the archaeological record is critical to our understanding human fishing adaptations in the North American Great Basin over time. Unfortunately, in the absence of robust middle range techniques for interpreting fishbone assemblages, many studies have been limited in their capacity to engage in theoretical discussions of the role of fishing in forager subsistence regimes. The Northern Paiute in Oregon and Nevada exploited seasonally aggregated tui chub (Siphateles bicolor) through mass-harvesting techniques using nets and baskets. This article integrates experimental studies with ethnographic and archaeological data to infer the types of fishing gear that were used from the reconstructed sizes of tui chub remains. The mean size of fish assemblages is compared to the coefficient of variation to identify fishing techniques based on the size parameters of gear types, and a technology investment model is used to assess regional variations in commitments to fishing in open lake and marshland settings. Results are compared to tui chub assemblages from two protohistoric archaeological sites in eastern Oregon, revealing two distinctive fishing strategies with general implications for the organization of labor by hunter-gatherer fisherfolk.

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