Annual Periodicity in a Free-Living Hibernator, the Uinta Ground Squirrel

This study documents the timing of seasonal events and associated changes in body weights of Uinta ground squirrels (Spermophilus armatus) that live at three different altitudes. The investigation provides detailed field data for biologists investigating circannual rhythms and hibernation in the laboratory. Ground squirrels aroused and subsequently emerged from hibernation in an overlapping sequence: adult males first, followed by adult females, yearling females and yearling males. Within limits some climatic condition(s) delayed emergence and increased the over lap in emergence sequence. The duration of seasonal activities above ground averaged about 90 days for adult and yearling squirrels. Juveniles were active above ground for 60-70 days. Each summer, adult males and adult and yearling females immerged into estivation-hibernation about the same date. Yearling males immerged later and juveniles immerged last. Adult and yearling squirrels gained body weight rapidly except for brief periods during reproduction. Males began to gain weight after the breeding season. Female weights started to increase immediately after emergence but leveled off during lactation. Juveniles gained weight steadily after emergence from the natal burrow. Mean body weights of squirrels leveled off late in the active season. Seasonal activities and changes in body weights of Uinta ground squirrels were shifted back 6 weeks in time at higher elevations. The annual cycle of Uinta ground sqUirrels appeared to be the result of an interaction between an endogenous timing mechanism and the immediate environmental conditions. Arousal from hibernation occurred about the same date each year and was probably under endogenous control. After arousal, exogenous factors acted to shorten or lengthen subsequent phases in the annual cycle. Later arousal of squirrels at high altitudes indicated that endogenous timing mechanisms of the species are entrained to the enVironmental conditions encountered at the respective altitudes

Word Adjacency Graph Modeling: Separating Signal From Noise in Big Data

There is a need to develop methods to analyze Big Data to inform patient-centered interventions for better health outcomes. The purpose of this study was to develop and test a method to explore Big Data to describe salient health concerns of people with epilepsy. Specifically, we used Word Adjacency Graph modeling to explore a data set containing 1.9 billion anonymous text queries submitted to the ChaCha question and answer service to (a) detect clusters of epilepsy-related topics, and (b) visualize the range of epilepsy-related topics and their mutual proximity to uncover the breadth and depth of particular topics and groups of users. Applied to a large, complex data set, this method successfully identified clusters of epilepsy-related topics while allowing for separation of potentially non-relevant topics. The method can be used to identify patient-driven research questions from large social media data sets and results can inform the development of patient-centered interventions

Differential Parental Care by Adult Mountain Plovers, Charadrius montanus

We studied chick survival of the Mountain Plover (Charadrius montanus) in Montana and found that chicks tended by females had higher survival rates than chicks tended by males, and that chick survival generally increased during the nesting season. Differences in chick survival were most pronounced early in the nesting season, and may be related to a larger sample of nests during this period. When compared to information about the nest survival of male- and female-tended plover nests, our chick data suggest a trade-off for adult plovers between the egg and chick phases of reproduction. Because Mountain Plover pairs have clutches at two nests at two different locations and show differential success between the sexes during the egg and chick phases, we offer that the Mountain Plover breeding system favours optimizing annual recruitment in a dynamic ecologic setting driven by annually unpredictable drought, grazing, and predation pressures

Monitoring Low Density Avian Populations: An Example using Mountain Plovers

Declines in avian populations highlight a need for rigorous, broad-scale monitoring pro-grams to document trends in avian populations that occur in low densities across expansive landscapes. Accounting for the spatial variation and variation in detection probability inherent to monitoring programs is thought to be effort-intensive and time-consuming. We determined the feasibility of the analytical method developed by Royle and Nichols (2003), which uses presence-absence (detection-non-detection) field data, to estimate abundance of Mountain Plovers (Charadrius montanus) per sampling unit in agricultural fields, grassland, and prairie dog habitat in eastern Colorado. Field methods were easy to implement and results suggest that the analytical method provides valuable insight into population patterning among habitats. Mountain Plover abundance was highest in prairie dog habitat, slightly lower in agricultural fields, and substantially lower in grassland. These results provided valuable insight to focus future research into Mountain Plover ecology and conservation

Movements and Home Ranges of Mountain Plovers Raising Broods in Three Colorado Landscapes

We report movements and home-range sizes of adult Mountain Plovers (Charadrius montanus) with broods on rangeland, agricultural fields, and prairie dog habitats in eastern Colorado. Estimates of home range size (95% fixed kernel) were similar across the three habitats: rangeland (146.1 ha +/- 101.5), agricultural fields (131.6 ha +/- 74.4), and prairie dog towns (243.3 ha +/- 366.3). Our minimum convex polygon estimates of home-range size were comparable to those on rangeland reported by Knopf and Rupert (1996). In addition, movements - defined as the distance between consecutive locations of adults with broods - were equivalent across habitats. However, our findings on prairie dog habitat suggest that home-range size for brood rearing may be related to whether the prairie dog habitat is in a complex of towns or in an isolated town

Movements and Home Ranges of Mountain Plovers Raising Broods in Three Colorado Landscapes

We report movements and home-range sizes of adult Mountain Plovers (Charadrius montanus) with broods on rangeland, agricultural fields, and prairie dog habitats in eastern Colorado. Estimates of home range size (95% fixed kernel) were similar across the three habitats: rangeland (146.1 ha +/- 101.5), agricultural fields (131.6 ha +/- 74.4), and prairie dog towns (243.3 ha +/- 366.3). Our minimum convex polygon estimates of home-range size were comparable to those on rangeland reported by Knopf and Rupert (1996). In addition, movements - defined as the distance between consecutive locations of adults with broods - were equivalent across habitats. However, our findings on prairie dog habitat suggest that home-range size for brood rearing may be related to whether the prairie dog habitat is in a complex of towns or in an isolated town

Ricci flow for homogeneous compact models of the universe

Using quaternions, we give a concise derivation of the Ricci tensor for homogeneous spaces with topology of the 3-dimensional sphere. We derive explicit and numerical solutions for the Ricci flow PDE and discuss their properties. In the collapse (or expansion) of these models, the interplay of the various components of the Ricci tensor are studied. We dedicate this paper to honor the work of Josh Goldberg.Comment: 18 pages, 2 figure

Stability of complex hyperbolic space under curvature-normalized Ricci flow

Using the maximal regularity theory for quasilinear parabolic systems, we prove two stability results of complex hyperbolic space under the curvature-normalized Ricci flow in complex dimensions two and higher. The first result is on a closed manifold. The second result is on a complete noncompact manifold. To prove both results, we fully analyze the structure of the Lichnerowicz Laplacian on complex hyperbolic space. To prove the second result, we also define suitably weighted little H\"{o}lder spaces on a complete noncompact manifold and establish their interpolation properties.Comment: Some typos in version 2 are correcte

An Assessment of Factors Affecting Population Growth of the Mountain Plover

Effective conservation measures should target the most sensitive life history attributes of a species, assuming they are responsive to potential management actions. The Mountain Plover (Charadrius montanus) is a species of conservation concern with a patchy breeding distribution in western North America. Plovers prefer areas with short vegetation, bare ground, and disturbance for nesting. Current management tools, including grazing and burning, have been used to attract plovers and enhance nesting success. We used a stage-specific matrix model to study the influence of vital rates, e.g., juvenile and adult annual survival, on population growth rate in the Mountain Plover at two breeding sites in Colorado, South Park and Eastern Colorado, and one breeding site in Montana, USA. Our analysis was motivated by a need to 1) better understand the relationship between demographic rates and population growth rate, 2) assess current management tools for the plover by exploring their effect on population growth rate, and 3) identify areas of the plover’s population biology where additional demographic work is needed. Stochastic population growth rate was most influenced by adult survival, especially in Montana and South Park, Colorado (elasticities \u3e 0.60), and was least influenced by first-year reproduction (all elasticities \u3c 0.20). The modeled relationships between lambda and each demographic rate were generally weak (r2 \u3c 0.30) with the exception of number of eggs hatched per nest in Eastern Colorado (r2 = 0.63), chick survival in South Park (r2 = 0.40) and Montana (r2 = 0.38), and adult survival in Montana (r2 = 0.36). We examined the predicted increase in lambda that would result from increasing each demographic rate from its mean to the maximum value observed in our simulations. Chick and adult survival showed the greatest increase in lambda while eggs hatched per nest produced the smallest increase. Our results suggest that future conservation efforts should favor ways to increase adult or chick survival over efforts to increase nest success. In particular, adult survival rates during the stationary periods, i.e., summer and winter, are relatively high, implying that efforts to increase adult survival rates may need to focus on the migratory periods. Increasing chick survival should be a priority for efforts that are restricted to the breeding grounds because this life history stage is relatively short (\u3c 3 mo) and it offers opportunities for targeted short-term management activities in breeding areas