14,596 research outputs found
Effects of Various Combinations and Numbers of Lead: Iron Pellets Dosed in Wild-Type Captive Mallards
Final Report, Contract No. 14-16-0008-914INHS Technical Report prepared for unspecified recipien
Study of optimum discrete estimators in measurement analysis
Study of statistical techniques for obtaining estimates of true data parameters uses discrete measured quantities containing random error. These techniques develop estimation procedures as an iterative algorithm for digital computation in real time
A near-infrared and optical photometric study of the Sculptor dwarf spheroidal galaxy: implications for the metallicity spread
We present here a detailed study of the Sculptor dSph galaxy red giant branch
(RGB) and horizontal branch (HB) morphology, combining new near-infrared
photometry from CIRSI, with optical data from the ESO WFI. For a Sculptor-like
old and generally metal-poor system, the position of RGB stars on the
colour-magnitude diagram is mainly metallicity dependent. The advantage of
using optical-NIR colours is that the position of the RGB locus is much more
sensitive to metallicity than with optical colours alone. In contrast the
horizontal branch (HB) morphology is strongly dependent on both metallicity and
age. Therefore a detailed study of both the RGB in optical-NIR colours and the
HB can help break the age-metallicity degeneracy. Our measured photometric
width of the Sculptor giant branch corresponds to a range in metallicity of
0.75 dex. We detect the RGB and AGB bumps in both the NIR and optical
luminosity functions, and derive from them a mean metallicity of [M/H] = -1.3
+/- 0.1. From isochrone fitting we derive a mean metallicity of [Fe/H] = -1.42
with a dispersion of 0.2 dex. These photometric estimators are for the first
time consistent with individual metallicity measurements derived from
spectroscopic observations. No spatial gradient is detected in the RGB
morphology within a radius of 13 arcmin, twice the core radius. On the other
hand, a significant gradient is observed in the HB morphology index, confirming
the `second parameter problem' present in this galaxy. These observations are
consistent with an early extended period of star formation continuing in time
for a few Gyr. (Abridged)Comment: 9 pages, 10 figures. Accepted for publication in MNRA
Methods for injection error analysis and their comparison Scientific report no. 13
Formulation of direct and adjoint methods of trajectory injection error in vector matrix notation and compariso
Observations of an Alligator (Alligator mississippiensis) Nest and Behavior of Hatchlings in Clark County, with anecdotal observations of other Alligator Nests in Arkansas
Historically, the American alligator (Alligator mississippiensis) ranged through southern and much of eastern Arkansas. By the early 1900s, alligator populations had declined due to unregulated hunting, commercial exploitation, and habitat loss. In 1961, the Arkansas Game and Fish Commission (AGFC) established protection of this species, and in 1967 the U.S. Fish and Wildlife Service listed the alligator as an endangered species. The AGFC conducted a restocking program from 1972-1984, and the species made a full recovery in Arkansas. Still, little is known about reproductive biology in the state. We observed an alligator nest near Arkadelphia, Clark Co., the mound of which was 1.6 m long, 1.3 m across, and 43-56 cm in height. Because the nest had not hatched by a date late for the species, we opened the nest because some peeping by live hatchlings could be heard. The nest contained 33 eggs, of which 12 hatched the rest were unfertile or died early. We observed behaviors of baby alligators at the time of hatching from a wild nest, and the development of feeding behaviors while maintained in lab. Babies were aggressive and bit debris and each other while hatching, apparently to aid in their exit from the egg. Aggressive behaviors subsided, and young took crickets, earthworms, and shiners as food. After about 3 days, individuals who both grabbed parts of a shiner or earthworm began the spin behaviors to tear apart food items
THE INFLUENCE OF WATER QUALITY ON THE HOUSING PRICE AROUND LAKE ERIE
The primary objective of this paper is to estimate the influence of Lake Erie water quality on the housing price by taking spatial effects into account. The robust LM tests for spatial autocorrelation suggested that spatial error model specification is more likely model in our study. Fecal coliform counts and Secchi depth disk reading are used as water quality measures. In order to overcome the spatio-temporal aspects of Secchi depth disk reading data, Kriging was used for spatial prediction. We found the significant influences of both water quality measures on housing values. Gradient effects considering the distance from a beach and water quality variables are also observed.Public Economics,
Recommended from our members
Effects of ultrasound on the growth and function of bone and periodontal ligament cells <i>in vitro</i>
The effects of therapeutic ultrasound (US) on tissue healing processes in vivo are likely to involve US-induced changes in key cellular functions. However, these have not yet been clearly delineated and the present study has, therefore, examined the effects of a single 5-min CW exposure of 3.00-MHz US on the growth and functional activity of a human osteoblast-like cell line (MG63 cells) and human periodontal ligament (PDL) cells in vitro. Although cell proliferation was found to be largely unaffected by spatial average intensity (ISA) values of between 140–990 mW/cm2, flow cytometry (FCM) analysis showed that there were pronounced and differential effects on cell function. Thus, bone-associated proteins were down-regulated, whereas collagen type I (COL I) was unaffected and fibronectin (FN) was up-regulated at low intensities in MG63 cells. In contrast, bone protein expression was found to be dose-dependent, and FN and COL I were down-regulated in PDL cells. These results show that US has potentially important effects on the functional activities of connective tissue cells in vitro, which could markedly influence tissue repair and regeneration processes in vivo
- …