Rate of Incisor Growth in the Mountain Pocket Gopher

1958 ◽  
Vol 39 (3) ◽  
pp. 380 ◽  
Author(s):  
Richard S. Miller
Keyword(s):  
1934 ◽  
Vol 49 (48) ◽  
pp. 1415 ◽  
Author(s):  
V. M. Hoge
Keyword(s):  

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 730
Author(s):  
Jonathan Z. Baskin ◽  
Brandon M. White ◽  
Amit Vasanji ◽  
Thomas E. Love ◽  
Steven J. Eppell

Animals with elodont dentition and unfused mandible symphyses are hypothesized to have symmetric incisor morphology. Since these animals maintain their teeth by gnawing, they may provide physiologic feedback on mechanical function when unilateral mandible defects are created that manifest as ipsilateral changes in tooth structure. This defect model would potentially generate important information on the functional/mechanical properties of implants. Rats’ and rabbits’ mandibles and teeth are analyzed with µCT at baseline and post-intervention (n = 8 for each). Baseline incisors were compared. In a unilateral mandible pilot study, defects—ranging from critical size defect to complete ramus osteotomies—were created to assess effect on dentition (rats, n = 7; rabbits, n = 6). Within 90% confidence intervals, animals showed no baseline left/right differences in their incisors. There are apparent dental changes associated with unilateral defect type and location. Thus, at baseline, animals exhibit statistically significant incisor symmetry and there is an apparent relationship between mandible defect and incisor growth. The baseline symmetry proven here sets the stage to study the degree to which hemi-mandible destabilizing procedures result in measurable & reproducible disruption of dental asymmetry. In a validated model, an implant designed to function under load that prevents incisor asymmetry would provide supporting evidence that the implant has clinically useful load-bearing function.


1999 ◽  
Vol 77 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Heather R Kleb ◽  
Scott D Wilson

Few studies have compared scales of heterogeneity among plant communities. We predicted that differences in the sizes of dominant species should allow us to detect small-scale (<256 cm) heterogeneity in mixed-grass prairie but not in adjacent aspen forest. We examined light penetration, soil moisture, available N, elevation, species composition, and plant mass at 10 locations in prairie and forest in both spring and summer. Variables were measured in 1-cm2 plots arranged in pairs separated by 0-256 cm. Several variables in prairie (elevation, litter mass, light penetration, and species composition) showed significant evidence for scale within the range examined. In contrast, only one variable in forest (light penetration in summer) showed evidence for scale in the same range. The scale of heterogeneity in prairie was consistent with the scale of two possible causes, species composition and elevation variability due to northern pocket gopher (Thomomys talpoides Richardson) activity, both of which varied significantly in prairie but not in forest. Whereas some aboveground factors (light and litter mass) varied within the range examined, belowground factors (water and N) did not, suggesting that the scale of heterogeneity differs between above- and below-ground factors. In total, the results suggest that differences in the scale of heterogeneity between prairie and forest reflect the relative sizes of the dominant plants.Key words: aspen, forest, heterogeneity, light, nitrogen, prairie, scale, soil, water.


Author(s):  
C. Youmans ◽  
R. Moore

Several important environmental factors which affect the dynamics of pocket gopher populations have been identified: water content at peak snowpack and depth of snow in spring (Hansen and Ward, 1966; Reid, 1973); weather and Its influence on annual food supplies and cover (Howard and Childs, 1959); production of annual and perennial forbs (Keith et al., 1959; Tietjen et al., 1967); and ground water levels and snow depths (Ingles, 1949; Hansen, 1962). A need for specific information on pocket gophers in Pelican Valley, Yellowstone National Park arose from interest in interactions between grizzly bears (Ursus arctos horribilis) and northern pocket gophers (Thomomys talpoides). Mealey (1975) and Graham (1978) suggested that pocket gophers and their caches may serve as seasonally important food items for grizzlies in Yellowstone National Park.


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