Inferring Stratigraphic Position of Fossil Vertebrates from the Niobrara Chalk of Western Kansas

The stratigraphy of the Smoky Hill Chalk Member of the Niobrara Chalk of western Kansas is well understood as a result of the work of Hattin (1982) and Stewart (1988). Marker units identified by Hattin (1982) allow quick determination of the stratigraphic position of a specific outcrop. This study demonstrates that it is now possible to determine the stratigraphic positions of specimens from locality data, thus permitting one to infer stratigraphic position of specimens collected long ago. This technique is particularly useful in the upper half of the Smoky Hill Chalk Member, where biostratigraphy is not informative. The stratigraphic distribution of the type skulls of the pterosaur Pteranodon is examined as an example of the procedure, which in turn demonstrates that the procedure can have the power to reject hypotheses. Inferring stratigraphic positions of fossil vertebrates may be useful in further studies of the large collections of fossil vertebrates from the Smoky Hill Chalk Member. In addition, examination of the stratigraphic distribution of outcrops of the Smoky Hill Chalk Member in western Kansas suggests that most of the fossil vertebrates collected from the member came from a rather restricted stratigraphic interval between Marker Units 15 and 20

Reassessment of the Triassic archosauriform Scleromochlus taylori: Neither runner nor biped, but hopper

The six known specimens of Scleromochlus taylori and casts made from their negative impressions were examined to reassess the osteological evidence that has been used to interpret Scleromochlus’s locomotion and phylogenetic relationships. It was found that the trunk was dorsoventrally compressed. The upper temporal fenestra was on the lateral surface of skull and two-thirds the size of the lower, the jaw joint posteriorly placed with short retroarticular process, and teeth short and subconical, but no evidence of external nares or antorbital fossae was found. The posterior trunk was covered with ~20 rows of closely spaced transversely elongate dorsal osteoderms. The coracoid was robust and elongate. The acetabulum was imperforate and the femoral head hemispherical and only weakly inturned such that the hip joint was unsuited to swinging in a parasagittal plane. The presence of four distal tarsals is confirmed. The marked disparity of tibial and fibular shaft diameters and of proximal tarsal dimensions indicates that the larger proximal tarsal is the astragalus and the significantly smaller tarsal is the calcaneum. The astragalus and calcaneum bear little resemblance to those of Lagosuchus, and the prominent calcaneal tuber confirms that the ankle was crurotarsal. There is no evidence that preserved body and limb postures are unnatural, and most specimens are preserved in what is interpreted as a typical sprawling resting pose. A principal component analysis of skeletal measurements of Scleromochlus and other vertebrates of known locomotor type found Scleromochlus to plot with frogs, and that finding combined with skeletal morphology suggests Scleromochlus was a sprawling quadrupedal hopper. Phylogenetic analyses found that Scleromochlus was not an ornithodiran, but was either within the Doswelliidae or outside the clade consisting of the most recent common ancestor of the Erythrosuchidae and Archosauria and all its descendants

Local u'g'r'i'z' Standard Stars in the Chandra Deep Field-South

Because several observing programs are underway in various spectral regimes to explore the Chandra Deep Field South (CDF-S), the value of local photometric standards is obvious. As part of an NOAO Surveys Program to establish u'g'r'i'z' standard stars in the southern hemisphere, we have observed the central region of the CDF-S to create local standards for use by other investigators using these filters. As a courtesy, we present the CDF-S standards to the public now, although the main program will not finish until mid-2005.Comment: Accepted by AJ (scheduled for October 2003 issue). 26 pages, 5 tables, 5 figures. High resolution version of Figure 7 available at http://home.fnal.gov/~dtucker/Southern_ugriz/index.htm

Nonorthogonal Quantum States Maximize Classical Information Capacity

I demonstrate that, rather unexpectedly, there exist noisy quantum channels for which the optimal classical information transmission rate is achieved only by signaling alphabets consisting of nonorthogonal quantum states.Comment: 5 pages, REVTeX, mild extension of results, much improved presentation, to appear in Physical Review Letter

Serving Others at the Expense of Self: The Relationship Between Nonprofit CEO Compensation and Performance in Trade and Professional Associations

This paper investigates the organizational importance of relative CEO compensation in trade associations and professional societies. It is known that there is variation in how much pay is tied to performance in different subcategories of nonprofit organizations. However, instead of looking at how performance affects pay, we investigate how CEO compensation affects organization performance when CEOs are aware of their peer compensation and are able to influence their own. We hypothesized that CEOs who knowingly earn less will be associated with both greater financial and nonfinancial organizational performance. This altruistic perspective draws on theories from leadership and psychology rather than the more typical agency perspective and focuses on the alignment between CEO and stakeholders in a nonprofit setting. We find strong support for the relationship between lower relative CEO compensation and organization performance, while results for the moderating effect of organizational size are mixed

Genome sequence analysis of La Crosse virus and in vitro and in vivo phenotypes

<p>Abstract</p> <p>Background</p> <p>La Crosse virus (LACV), family <it>Bunyaviridae</it>, is a mosquito-borne virus recognized as a major cause of pediatric encephalitis in North America with 70–130 symptomatic cases each year. The virus was first identified as a human pathogen in 1960 after its isolation from a 4 year-old girl who suffered encephalitis and died in La Crosse, Wisconsin. The majority of LACV infections are mild and never reported, however, serologic studies estimate infection rates of 10–30/100,000 in endemic areas.</p> <p>Results</p> <p>In the present study, sequence analysis of the complete LACV genomes of low-passage LACV/human/1960, LACV/mosquito/1978, and LACV/human/1978 strains and of biologically cloned derivatives of each strain, indicates that circulating LACVs are genetically stable over time and geographic distance with 99.6–100%, 98.9–100%, 97.8–99.6%, and 99.2–99.7% amino acid identity for N, NsS, M polyprotein, and L proteins respectively. We identified 5 amino acid differences in the RNA polymerase and 4 nucleotide differences in the non-coding region of the L segment specific to the human virus isolates, which may result in altered disease outcomes.</p> <p>Conclusion</p> <p>All three wild type viruses had similar <it>in vitro </it>growth kinetics and phenotypes in mosquito C6/36 and Vero cells, and similar levels of neurovirulence and neuroinvasiveness in Swiss Webster mice. The biologically cloned derivative of LACV/human/1960 was significantly less neuroinvasive than its uncloned parent and differed in sequence at one amino acid position in the G_Nglycoprotein, identifying this residue as an attenuating mutation.</p