An Examination of the Inorganic Nitrogen Status of a Soil of the Alaskan Coastal Tundra Plain

This experiment was designed to measure in situ concentrations of NH4+ and NO3--N in a soil of the arctic coastal tundra plain, to determine if nitrification was taking place in this soil and to determine if the vascular plants growing in this soil could assimilate NH4+-N. The extractable NH4+-N concentration was approximately 40 μg/g in the 01 horizon and 10 μg/g in the 02 horizon. The NO3--N concentration was approximately 5 μg/g in the 01 horizon and 4 μg/g in the 02 horizon. The presence of NO3--N in this soil indicates that nitrification is taking place but perfusion experiments indicate that it is not bacterial nitrification. Fungi may be responsible for nitrification in this soil. Corex aquatilis, a common plant in the study area, was found to readily assimilate NH4+-N as well as NO3--N

A proposed method for evaluation of morphological changes in the condyle and glenoid fossa by cone beam computed tomography

The difficulty with three-dimensional analyses remains with the myriad of data that is possible to derive from a volume. The goal of this study is to report 3D changes in the temporomandibular joint in a reliable and quantifiable way. The approach included plotting specific referents on the mandibular condyle and tracking them in magnitude (mm) and direction (°) on a reference plane after superimposing the cone beams three-dimensionally on the inferior alveolar nerve canal and the lower contour of the third molar tooth germ. Two sets of measurements were compared for reliability and each measurement showed varied correlation. Linear measurements tended to be more reliable than component and angular measurements. Angular measurements were generally the least reliable. The varied reliability results are likely due to the difficulty in superimposing limited field of view (FOV) cone beam radiographs because of inadequate structures that are able to be superimposed

Collision Integrals for the Exponential Attractive Potential

Numerical integration calculation of collision integrals for exponential attractive potential of gase

Economic Impact of Wildlife-Associated Recreation Expenditures in the Southeast United States: A General Equilibrium Analysis

The economic impact of wildlife-associated recreation in the Southeast United States was evaluated using a general equilibrium model. Exogenous demand shocks to the regional economy were based on estimates of expenditures by wildlife recreationists on hunting, fishing, and wildlife watching activities. Counterfactual simulations were carried out, making alternative assumptions about labor and capital mobility and their supply. Without wildlife-associated recreation expenditures, regional employment would have been smaller by up to 783 thousand jobs, and value added would have been $22 to$48 billion less. These findings underscore the significance of regional factor market conditions in economic impact and general equilibrium analysis.general equilibrium modeling, input-output analysis, regional economic impact, wildlife-associated recreation activities, Resource /Energy Economics and Policy, R13, R15, Q26,

Automatic calculation of the transport collision integrals with tables for the morse potential

Computer program for calculation of transport collision integrals with tables for Morse potentia

Empty pews take a financial toll on many US congregations

Most Christian churches were relying heavily on 'collection plates' to pay their bills before the pandemic struck. And less than half were doing any online fundraising as of 2018.Lilly Endowment Inc

The Luminosity Function for L>L* Galaxies at z > 3

Through use of multiband (U, B, R, I) photometry we have isolated high redshift (3.0<z<3.5) galaxy candidates in a survey of 1.27 deg^2 to R = 21.25 and a survey of 0.02 deg^2 to R = 23.5. Our pool of candidates constrains the nature of the 3.0 < z < 3.5 luminosity function over the range L* < L < 100 L*, if we grant a similar level of completeness to these data as for very faint samples (to R = 25.5) selected in a similar fashion. Our constraints agree with the high redshift sky density at R = 20.5 estimated from Yee et al.'s (1996) serendipitous discovery of a bright, z = 2.7 galaxy, as well as the density at R ~ 23 by Steidel et al. (1996b). We strongly rule out -- by more than two orders of magnitude at M(R) = -25 -- the L > L* luminosity function for z = 3-5 galaxies obtained by a photometric redshift analysis of the Hubble Deep Field (HDF) by Gwyn & Hartwick (1996). Our results at R ~ 23 are more consistent with the photometric redshift analysis of the faint HDF galaxies by Sawicki & Yee (1996), but our present upper limits at the brightest magnitudes (R < 21.5, M(R) < -24) allow more generous volume densities of these super-L* galaxies.Comment: Accepted for publication in ApJ Letters; 14 pages Latex, including 3 figure

Survey incompleteness and the evolution of the QSO luminosity function

We concentrate on a type of QSO survey which depends on selecting QSO candidates based on combinations of colors. Since QSO's have emission lines and power-law continua, they are expected to yield broadband colors unlike those of stellar photospheres. Previously, the fraction of QSO's expected to be hiding (unselected) within the locus of stellar (U-J, J-F) colors was estimated at about 15 percent. We have now verified that the KK88 survey is at least 11 percent incomplete, but have determined that it may be as much as 34 percent incomplete. The 'missing' QSO's are expected to be predominantly at z less than or = 2.2. We have studied the proper motion and variability properties of all stellar objects with J less than or = 22.5 or F less than or = 21.5 in the SA 57 field which has previously been surveyed with a multicolor QSO search by KK88