A Biography of John Dorsett

John Dorsett came to Savannah from New York City sometime prior to July 1838. During: his brief eight year residence in Savannah he became well known in both the social and business communities. At the time of his death he left a wife and three children but the absence of a will has decreed that the value of :his estate be lost in history.https://digitalcommons.georgiasouthern.edu/sav-bios-lane/1054/thumbnail.jp

Soil Nitrogen Transformations And Retention During A Deciduous To Coniferous Successional Transition

Thesis (Ph.D.) University of Alaska Fairbanks, 2005The mineralization, retention and movement of soil nitrogen (N) was investigated in forest types which encompass one of the most dramatic plant successional transitions in the boreal forest---the shift from deciduous, mid-succession, stands of balsam poplar (Poputus balsamifera) to coniferous, late-succession, stands of white spruce (Picea glauca). Nitrogen is an essential nutrient that often limits plant productivity in the boreal forest. Nitrogen uptake by plants is constrained by the activity of soil microbes and their associated exoenzymes which depolymerize (break down) organic molecules and release forms of N that are useable by plants (e.g., amino acids, ammonium and nitrate). The availability of labile carbon (C) is generally thought to limit soil microbes; however, it has been hypothesized that soil microbes in floodplain stands of balsam poplar are actually N limited. Balsam poplar trees also have large N requirements; thus, the overall demand for N is considerable in these stands and biological N retention should be high. In contrast, lower primary productivity and more recalcitrant soil organic matter in white spruce stands should result in comparatively less immobilization and less retention of N in this stand type. Experimental N additions resulted in the acceleration of net N mineralization and nitrate leaching in both stand types, probably because biological N demand was rapidly satiated. In balsam poplar soil, net nitrification was greatly stimulated by N additions; while in white spruce soil only net ammonification was stimulated; indicating that different mechanisms control ammonium oxidation or nitrate immobilization in these stands. Nitrogen additions did not affect soil microbial biomass in either stand. Results from a laboratory soil incubation study indicate that, compared to mid-succession soil, soil organic matter in late succession stands was more labile and the mineralization of C and N were significantly more temperature sensitive. Thus, climatic warming may result in the release of a larger proportion of soil C and N from late succession stands. A separate study examining soil solution N concentrations and movement showed that the Tanana River is a source of active layer nitrate during the growing season in both mid and late succession stands

Summary statement of the Asilomar conference on recombinant DNA molecules

This meeting was organized to review scientific progress in research on recombinant DNA molecules and to discuss appropriate ways to deal with the potential biohazards of this work. Impressive scientific achievements have already been made in this field and these techniques have a remarkable potential for furthering our understanding of fundamental biochemical processes in pro- and eukaryotic cells. The use of recombinant DNA methodology promises to revolutionize the practice of molecular biology. Although there has as yet been no practical application of the new techniques, there is every reason to believe that they will have significant practical utility in the future

Generalization of tiled models with curved surfaces using typification

Especially for landmark buildings or in the context of cultural heritage documentation, highly detailed digital models are being created in many places. In some of these models, surfaces are represented by tiles which are individually modeled as solid shapes. In many applications, the high complexity of these models has to be reduced for more x efficient visualization and analysis. In our paper, we introduce an approach to derive versions at different scales from such a model through the generalization method of typification that works for curved underlying surfaces. Using the example of tiles placed on a curved roof - which occur, for example, very frequently in ancient Chinese architecture, the original set of tiles is replaced by fewer but bigger tiles while keeping a similar appearance. In the first step, the distribution of the central points of the tiles is approximated by a spline surface. This is necessary because curved roof surfaces cannot be approximated by planes at large scales. After that, the new set of tiles with less rows and/or columns is distributed along a spline surface generated from a morphing of the original surface towards a plane. The degree of morphing is dependent on the desired target scale. If the surface can be represented as a plane at the given resolution, the tiles may be converted to a bump map or a simple texture for visualization. In the final part, a perception-based method using CSF (contrast sensitivity function) is introduced to determine an appropriate LoD (level of detail) version of the model for a given viewing scenario (point of view and camera properties) at runtime.BMBF/GDI-Grid projectNational Basic Reseach Program of China/2010CB731800National High Technology Research and Development Program of China/2008AA12160

An unappreciated role for RNA surveillance

BACKGROUND: Nonsense-mediated mRNA decay (NMD) is a eukaryotic mRNA surveillance mechanism that detects and degrades mRNAs with premature termination codons (PTC(+ )mRNAs). In mammals, a termination codon is recognized as premature if it lies more than about 50 nucleotides upstream of the final intron position. More than a third of reliably inferred alternative splicing events in humans have been shown to result in PTC(+ )mRNA isoforms. As the mechanistic details of NMD have only recently been elucidated, we hypothesized that many PTC(+ )isoforms may have been cloned, characterized and deposited in the public databases, even though they would be targeted for degradation in vivo. RESULTS: We analyzed the human alternative protein isoforms described in the SWISS-PROT database and found that 144 (5.8% of 2,483) isoform sequences amenable to analysis, from 107 (7.9% of 1,363) SWISS-PROT entries, derive from PTC(+ )mRNA. CONCLUSIONS: For several of the PTC(+ )isoforms we identified, existing experimental evidence can be reinterpreted and is consistent with the action of NMD to degrade the transcripts. Several genes with mRNA isoforms that we identified as PTC(+ )- calpain-10, the CDC-like kinases (CLKs) and LARD - show how previous experimental results may be understood in light of NMD

Overview of Recent Flight Flutter Testing Research at NASA Dryden

In response to the concerns of the aeroelastic community, NASA Dryden Flight Research Center, Edwards, California, is conducting research into improving the flight flutter (including aeroservoelasticity) test process with more accurate and automated techniques for stability boundary prediction. The important elements of this effort so far include the following: (1) excitation mechanisms for enhanced vibration data to reduce uncertainty levels in stability estimates; (2) investigation of a variety of frequency, time, and wavelet analysis techniques for signal processing, stability estimation, and nonlinear identification; and (3) robust flutter boundary prediction to substantially reduce the test matrix for flutter clearance. These are critical research topics addressing the concerns of a recent AGARD Specialists' Meeting on Advanced Aeroservoelastic Testing and Data Analysis. This paper addresses these items using flight test data from the F/A-18 Systems Research Aircraft and the F/A-18 High Alpha Research Vehicle

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at root s=7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of root s = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb(-1). The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 &lt; p(T) &lt; 400 GeV and rapidity in the range vertical bar y vertical bar &lt; 2.1. The b&lt;(b)over bar&gt;-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 &lt; m(jj) &lt; 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured b (b) over bar -dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1140/epjc/s10052-011-1846-4</p

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of root s = 7 TeV corresponding to an integrated luminosity of 38 pb(-1). Jets are reconstructed with the anti-k(t) algorithm with distance parameters R = 0.4 or R = 0.6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT &gt;= 20 GeV and pseudorapidities vertical bar eta vertical bar &lt; 4.5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2.5 % in the central calorimeter region (vertical bar eta vertical bar &lt; 0.8) for jets with 60 &lt;= p(T) &lt; 800 GeV, and is maximally 14 % for p(T) &lt; 30 GeV in the most forward region 3.2 &lt;= vertical bar eta vertical bar &lt; 4.5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon p(T), the sum of the transverse momenta of tracks associated to the jet, or a system of low-p(T) jets recoiling against a high-p(T) jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-p(T) jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined.ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1140/epjc/s10052-013-2304-2 </p