Nitrogen Partitioning and Mobilization Patterns in Bean Plants

The assimilation and distribution of N in the vegetative and reproductive plant parts of edible grain legumes are important processes determining final seed and protein yields. Limited information is available describing these processes for beans (Phaseolus vulgaris L.J. The objective of this study was to measure the N partitioning and mobilization patterns in this important grain legume. Two dry bean cultivars, '3512' and '3591', were labeled with either K15NO3 or 15N2 at the late vegetative (V5), early pod development (R2-R3), and seed filling (R6) developmental stages in the greenhouse. Initial N partitioning was evaluated on plants harvested 48 h after the start of labeling, while the N mobilization patterns were evaluated on the 15NO3 labeled plants harvested at subsequent developmental stages and at physiological maturity (R9). Both cultivars had similar dry weight and N distribution patterns throughout development, but 3512 had a larger final seed yield while the final seed N concentrations were greater for 3591. These differences developed from R6 to R9 where the dry weight increase in 3591 had a N concentration of 28.1 g kg-1 compared with 9.9 g kg-1 for 3512. The relative proportion of 15N in each plant part was dependent upon the growth stage and 15N source, and was independent of cultivar. Greater proportions were found in the mature leaves and roots of plants labeled with 15NO3, and in the seed and nodules in those plants labeled with 15N2 at all growth stages. Pods and seeds were major sinks from both 15N sources when applied at R2-R3 and R6, respectively. The seed at R9 contained 64, 73, and 84% of the labeled-N applied at the V5, R2-R3, and R6 growth stages, respectively. The seed contained an average of 68% of the total plant N and 53% of the total plant dry weight at R9. These data indicate that the photosynthetic and N2-fixation activities during seed filling can have a significant influence on the final seed N concentrations and yield

Nitrogen Sources for Bean Seed Production

Beans (Phaseolus valgaris L.) often respond to N fertilization; however, N fertilization is not practiced for maximum seed production in southern Idaho. This suggests that the symbiotic relationship and/or soil N sources can provide most of the N needed by this legume. Our objective was to evaluate the relative contribution of the symbiotic-nonsymbiotic N sources by studying the effects of N fertilization on the symbiotic N? fixation and seed yields under field conditions. Experiments were conducted on silt loam soils belonging to the Portneuf series (Xerollic Calciortnids). An acetylene reduction (AR) method was used to determine the effect of N fertilization treatments on the relative seasonal Ng (AR) fixation. The symbiotic N? fixation was also estimated by the equation, N? = Nup — (Nl + Nm - Nh) — ?Nf, where Nup is the accumulated N uptake measured near physiological maturity, Nl and Nh are the amounts of soil NO?-N in the root zone before planting and near physiological maturity, Nm is the N mineralized from soil organic N sources, and ? is the recovery of the N fertilizer (Nf) applied. Estimates of the N fertilizer recoveries were obtained from two experiments using 15N-depleted (NH?)?SO?. The symbiotic N? relationship contributed up to 90 kg N/ha, which was 40 to 50% of the total N found in bean plants near physiological maturity. The amount of symbiotic N? fixed decreased as the available soil N or fertilizer N increased, and increased as the N required by the individual cultivars increased. The response to N fertilization depended upon the cultivar, as well as on the N available from soil sources. Measured fertilizer N recoveries ranged from 7 to 33%. An average of 52% of the total N uptake near physiological maturity was taken up after the maximum symbiotic Ng(AR) rate occurred; while the seed contained an average of 60% of the total N uptake. A low N fertilization rate (< 50 kg N/ha) when the soil Nl was low (<50 kg N/ha) ensured an early vigorous plant growth but did not always increase seed yields. Higher N fertilization rates may be required on soils with lower amounts of mineralizable N

Tourism destination competitiveness: second thoughts on the world economic forum reports

The Travel and Tourism Competitiveness Reports of the World Economic Forum elaborate the Travel and Tourism Competitiveness Index (TTCI) as an overall measure of destination competitiveness for 130 economies worldwide. From a tourism management point of view, a measure such as the TTCI is expected to be instrumental in explaining and predicting the tourism performance of receiving countries. This study explores several ways to transform the TTCI into a formative structural model. Partial least squares path modelling, PLS regression, mixture modelling and non-linear covariance-based structural equation modelling are applied to examine the TTCI's predictive power. The analysis probes possible measures for improvement. The destination countries may be subject to unobserved heterogeneity with regard to how the various constituents of competitiveness act on tourism performance. Interaction phenomena seem to prohibit a simple cause-effect pattern and non-linear relationships show encouraging results

True and intentionally fabricated memories

The aim of the experiment reported here was to investigate the processes underlying the construction of truthful and deliberately fabricated memories. Properties of memories created to be intentionally false - fabricated memories - were compared to properties of memories believed to be true - true memories. Participants recalled and then wrote or spoke true memories and fabricated memories of everyday events. It was found that true memories were reliably more vivid than fabricated memories and were nearly always recalled from a first person perspective. In contrast, fabricated differed from true memories in that they were judged to be reliably older, were more frequently recalled from a third person perspective, and linguistic analysis revealed that they required more cognitive effort to generate. No notable differences were found across modality of reporting. Finally, it was found that, intentionally fabricated memories were created by recalling and then ‘editing’ true memories. Overall, these findings show that true and fabricated memories systematically differ, despite the fact that both are based on true memories

Energy levels of Bk249 populated in the α decay of 99253Es and β- Decay of 96249Cm

The level structure of Bk249 has been investigated by measuring the γ-ray spectra of an extremely pure Es253 sample obtained by milking this nuclide from Cf253 source material produced in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Additional information on the Bk249 levels was obtained from the β - decay study of Cm249, produced by neutron irradiation of Cm248. Using the results of the present study together with the data from previous Cm248(α,t) and Cm248(He3,d) reactions, the following single-particle states have been identified in Bk249: 7/2+[633], 0.0 keV; 3/2-[521], 8.78 keV; 1/2+[400], 377.55 keV; 5/2+[642], 389.17 keV; 1/2-[530], 569.20 keV; 1/2-[521], 643.0 keV; 5/2-[523], 672.9 keV; and 9/2+[624], 1075.1 keV. Four vibrational bands were identified at 767.9, 932.2, 1150.7, and 1223.0 keV with tentative assignments of {7/2+ [633] 1-}9/2-, {7/2+ [633] 0-}7/2-, {7/2+ [633] 1-}5/2-, and {7/2+ [633] 0+}7/2+, respectively. A band at 899.9 keV was observed in γ-γ coincidence measurements and given a tentative spin assignment of 3/2. It is possibly associated with a 2- phonon coupled to the ground state, with configuration {7/2+ [633] 2-}3/2-. Three levels at 624.3, 703.5, and 769.1 keV were assigned spins of 5/2, 7/2, and 9/2, respectively. These could be the members of the 3/2+ [651] band, expected in this energy region

Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

We present the first measurement of directed flow ($v_1$) at RHIC. $v_1$ is found to be consistent with zero at pseudorapidities $\eta$ from -1.2 to 1.2, then rises to the level of a couple of percent over the range $2.4 < |\eta| < 4$. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure

Azimuthal anisotropy: the higher harmonics

We report the first observations of the fourth harmonic (v_4) in the azimuthal distribution of particles at RHIC. The measurement was done taking advantage of the large elliptic flow generated at RHIC. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 4 pages, 6 figures, contribution to the Quark Matter 2004 proceeding

Plasma Wakefield Acceleration with a Modulated Proton Bunch

The plasma wakefield amplitudes which could be achieved via the modulation of a long proton bunch are investigated. We find that in the limit of long bunches compared to the plasma wavelength, the strength of the accelerating fields is directly proportional to the number of particles in the drive bunch and inversely proportional to the square of the transverse bunch size. The scaling laws were tested and verified in detailed simulations using parameters of existing proton accelerators, and large electric fields were achieved, reaching 1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found in this case.Comment: 9 pages, 7 figure

The energy dependence of ptp_t angular correlations inferred from mean-ptp_{t} fluctuation scale dependence in heavy ion collisions at the SPS and RHIC

We present the first study of the energy dependence of $p_t$ angular correlations inferred from event-wise mean transverse momentum fluctuations in heavy ion collisions. We compare our large-acceptance measurements at CM energies $\sqrt{s_{NN}} =$ 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. $p_t$ angular correlation structure suggests that the principal source of $p_t$ correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with $\ln \sqrt{s_{NN}}$ from the onset of observable jet-related fluctuations near 10 GeV.Comment: 10 pages, 4 figure

All-optical switching and strong coupling using tunable whispering-gallery-mode microresonators

We review our recent work on tunable, ultrahigh quality factor whispering-gallery-mode bottle microresonators and highlight their applications in nonlinear optics and in quantum optics experiments. Our resonators combine ultra-high quality factors of up to Q = 3.6 \times 10^8, a small mode volume, and near-lossless fiber coupling, with a simple and customizable mode structure enabling full tunability. We study, theoretically and experimentally, nonlinear all-optical switching via the Kerr effect when the resonator is operated in an add-drop configuration. This allows us to optically route a single-wavelength cw optical signal between two fiber ports with high efficiency. Finally, we report on progress towards strong coupling of single rubidium atoms to an ultra-high Q mode of an actively stabilized bottle microresonator.Comment: 20 pages, 24 figures. Accepted for publication in Applied Physics B. Changes according to referee suggestions: minor corrections to some figures and captions, clarification of some points in the text, added references, added new paragraph with results on atom-resonator interactio