Classification of Red Beds at Point of Rocks, Morton County, Kansas: A Historical Review

The age of red beds exposed below the bluff-capping Ogallala Formation at Point of Rocks in Morton County, Kansas, has been disputed since they were first recognized in the late 1800s. Over the years, nearly 25 maps and reports have variously classified the strata as Cretaceous, Jurassic, Triassic, or Permian, creating an interesting history of speculation and stratigraphic nomenclature. Many of the interpretations relied on the indirect method of comparing lithologies to similar exposures in surrounding states, but none were in-depth studies. Until recently, the Kansas Geological Survey has considered the rocks to be Jurassic based on Zeller (1968), the currently recognized stratigraphic guide and chart for Kansas. A comprehensive study by Smith et al. (2015)--using outcrop descriptions, subsurface information, and detrital zircon data--constrained the age of the red beds at Point of Rocks, assigning them to the Guadalupian Big Basin Formation, the uppermost Permian unit in Kansas

Certifying the restricted isometry property is hard

This paper is concerned with an important matrix condition in compressed sensing known as the restricted isometry property (RIP). We demonstrate that testing whether a matrix satisfies RIP is NP-hard. As a consequence of our result, it is impossible to efficiently test for RIP provided P \neq NP

Paleoecology of the Permian (Wolfcampian) Phylloid Alga Calcipatera from an In Situ Occurrence in Kansas, U.S.A.

In situ occurrences of the calcareous marine phylloid alga Calcipatera cottonwoodensis in the Permian Cottonwood Limestone Member (Beattie Limestone) occur in Greenwood County, Kansas, in association with platy algal packstones, which are the phylloid algal facies most commonly described in the literature. The in situ algal facies occurs in the upper 0.45 m of an exposure where it is overlain and underlain by algal packstones composed of transported and broken fragments of Calcipatera cottonwoodensis. Calcipatera cottonwoodensis colonized coarse carbonate sands or carbonate mud substrates. During growth, carbonate mud accumulated in the cup-shaped thalli, and death followed when the rate of sedimentation exceeded the rate of algal growth. The three lithologies--substrate, cup-filling, and smothering--are easily recognized on polished surfaces. Other members of the Calcipatera cottonwoodensis benthic community are Shamovella, encrusting and boring algae, foraminiferids, fenestrate and ramose bryozoans, brachiopods, bivalves, gastropods, trilobites, ostracodes, and echinoids. This occurrence and biotic association compares well with those described by Toomey (1976) and Wahlman (1988, 2002) from the Permian (Wolfcampian) of West Texas

THE INFLUENCE OF BREEDING EXPERIENCE ON NEST SUCCESS IN RED-WINGED BLACKBIRD

The Red-winged Blackbird (Agelaius phoeniceus) is a polygynous species, and females are typically responsible for the majority of parental care. Despite their limited involvement, males can contribute to reproduction through nest defense and the feeding of nestlings. Some aspects of nest defense may be learned, and older males are more likely to feed young, suggesting that males with previous breeding experience may enjoy higher nest success than their naïve counterparts. We manipulated territory ownership on 10 wetlands in central North Dakota in order to examine the influence of breeding experience on reproductive success. We found no evidence that breeding experience increased nest survival (x– = 23.0%) or increased the number of fledglings per nest (x– = 2.2). In this population, territory quality may contribute more to nesting success than male parental contributions

Comment on "A centrosome-independent role for gamma-TuRC proteins in the spindle assembly checkpoint"

Müller et al. (Reports, 27 October 2006, p. 654) showed that inhibition of the γ-tubulin ring complex (γ-TuRC) activates the spindle assembly checkpoint (SAC), which led them to suggest that γ-TuRC proteins play molecular roles in SAC activation. Because γ-TuRC inhibition leads to pleiotropic spindle defects, which are well known to activate kinetochore-derived checkpoint signaling, we believe that this conclusion is premature

Habitat Characteristics of Spring Blackbird Roosts in East-central South Dakota

In the northern Great Plains, blackbirds (Icteridae) roost almost exclusively in emergent-dominated wetlands. The physical characteristics of wetland roosts are not well understood. From March 20 to April 20, 1999, we studied 16 wetlands used as blackbird roosts in east-central South Dakota. Six wetlands had major roosts (range: 102,000-298,000 blackbirds); whereas, 10 wetlands had minor roosts (range: 2,010-34,000 blackbirds). Maximum roost size was correlated directly with emergent vegetation area (P = 0.05) and possibly with wetland basin area (P ≤ 0.10). Water depths were greater at used sites within wetlands of major roosts (median = 44 cm) than at used sites of minor roosts (median = 25 cm). Palustrine wetlands with large expanses of emergents (\u3e 100 ha) and water depths (\u3e 40 cm) had an increased likelihood of developing into major spring roosts in east-central South Dakota

Feeding Habitats of Spring-Migrating Blackbirds in East-central South Dakota

Between March 27 and April 21, 1998, we monitored blackbird (Icteridae) activity and habitat selection at a migratory staging area in east-central South Dakota. We used fixed-area observation points located within 20 l-km2 circular plots centered on four wetland basins that were used as night roosts. Each roost was surveyed four times, with the surveys spread evenly throughout the blackbird migration. We recorded the number of blackbird flocks, flock size and composition, habitat used, and behavior (e.g., loafing and feeding). Fifty percent (n = 242) of the 482 flocks recorded in the quadrats was observed loafing in trees of woodlots and shelterbelts. Feeding flocks preferred habitats classified as Corn (e.g., disked, plowed, and stubble corn fields) over two other foraging habitat categories (Cultivated and Grassland). A comparison of proportional availability of Cultivated habitat (soybean [Lathyrus odoratus] and wheat [Triticum aestivum] stubble, inclusive) against proportional use by feeding flocks indicated that this habitat was avoided. Grassland habitat (hayfields, CRP, and pasture) was used according to its availability. Intensity of Grassland use depended on time of survey (AM and PM), with use greater during the PM survey. A two-factor model (habitat, time, and the interaction term) provided the best parsimonious fit of 15 a priori models tested with Akaike\u27s information criterion (AICc). Selection of foraging habitats by blackbirds might reflect comparable strategies used by other early migrating granivores. This knowledge could help wildlife managers maximize the placement of corn field food plots for optimum benefit to wildlife species

A Rigorous Path Integral for Supersymmetric Quantum Mechanics and the Heat Kernel

In a rigorous construction of the path integral for supersymmetric quantum mechanics on a Riemann manifold, based on B\"ar and Pf\"affle's use of piecewise geodesic paths, the kernel of the time evolution operator is the heat kernel for the Laplacian on forms. The path integral is approximated by the integral of a form on the space of piecewise geodesic paths which is the pullback by a natural section of Mathai and Quillen's Thom form of a bundle over this space. In the case of closed paths, the bundle is the tangent space to the space of geodesic paths, and the integral of this form passes in the limit to the supertrace of the heat kernel.Comment: 14 pages, LaTeX, no fig

Precambrian nomenclature in Kansas

The informal stratigraphic term “Precambrian” is replaced by formal nomenclature—Proterozoic and Archean Eonothems/Eons—and the informal term Hadean. The Phanerozoic Eonothem/Eon, representing all rocks younger than the Proterozoic, is added. The Proterozoic is further divided into Paleoproterozoic, Mesoproterozoic, and Neoproterozoic Erathems/Eras. The name Rice Formation (Scott, 1966) is abandoned, and the use of the informal term “Rice unit” is recommended. The proposed name Rice Series (Berendsen, 1994) is not accepted. These changes are adopted by the Kansas Geological Survey (KGS) and the stratigraphic nomenclature of Zeller (1968) has been revised accordingly