Cumulative Cross Research Articles

Effect of two-spotted spider mite population (Tetranychus urticae Koch) on growth parameters and yield of the summer apple cv. Katja

Warabieda W. (2015): Effect of two-spotted spider mite population (Tetranychus urticae Koch) on growth parameters and yield of the summer apple cv. Katja. Hort. Sci. (Prague), 42: 167–175. The effect of two-spotted spider mite populations (Tetranychus urticae Koch) on the yield and growth parameters of the early-season apple cv. Katja was evaluated during a 3-year study. In the case of the colonisation of apple trees exceeding 1,462, 2,760 and 1,548 cumulative mite days (CMDs) in the subsequent years of research, a significant reduction of the cumulative yield (14 kg/tree) and of the cumulative trunk cross sectional area increase (5.7 cm2) was observed. No significant effect of spider mites on the average weight of the fruit was observed, while the pest affected fruit colouration. The calculated values of economic injury level were 60.5, 155.5 and 51.8 CMDs in subsequent years of the study, respectively. These values are much lower than the action threshold recommended in Poland and elaborated for the European red mite – Panonychus ulmi (Koch) on apple trees. The results suggest that the tolerance of early-season apple cultivars to T. urticae may be lower when compared to late-season varieties infested with P. ulmi; therefore, the decision to implement pest management for two-spotted spider mite should be taken at a lower infestation threshold than previously thought.

‘Buddhaʼs light’ of cumulative particles**Presented at the International Seminar Quarks-2014, Suzdal’, Russia, 2–8 June 2014

We show analytically that in the cumulative particles production off nuclei multiple interactions leads to a glory-like backward-focusing effect. Employing the small phase space method, we arrived at a characteristic angular dependence of the production cross section near the strictly backward direction. This effect takes place for any number of interactions of rescattered particles, either elastic or inelastic (with resonance excitations in intermediate states), when the final particle is produced near the corresponding kinematical boundary. In the final angles interval, including the value , the angular dependence of the cumulative production cross section can have a crater-like (or funnel-like) form. Such a behaviour of the cross section near the backward direction is in qualitative agreement with some of the available data. Explanation of this effect and the angular dependence of the cross section near are presented for the first time

Analytic calculation of 1-jettiness in DIS at O α s $$ \mathcal{O}\left({\alpha}_s\right) $$

We present an analytic $\mathcal O(\alpha_s)$ calculation of cross sections in deep inelastic scattering (DIS) dependent on an event shape, 1-jettiness, that probes final states with one jet plus initial state radiation. This is the first entirely analytic calculation for a DIS event shape cross section at this order. We present results for the differential and cumulative 1-jettiness cross sections, and express both in terms of structure functions dependent not only on the usual DIS variables $x$, $Q^2$ but also on the 1-jettiness $\tau$. Combined with previous results for log resummation, predictions are obtained over the entire range of the 1-jettiness distribution.

Influence of a one-neutron-excess projectile on low-energy incomplete fusion

Background: Incomplete fusion has been found to be an important contributor in light heavy-ion ($A\ensuremath{\le}20$) induced reactions even at slightly above barrier energies.Purpose: For better insight into the dynamics of incomplete fusion, the onset and influence of incomplete fusion need to be investigated in terms of projectile energy (${E}_{\mathrm{lab}}$) and entrance channel mass-asymmetry (${\ensuremath{\mu}}_{A}$). A rich set of experimental data on incomplete fusion may be useful to correlate the probability of incomplete fusion with the various entrance channel parameters and eventually to develop a theoretical model code for the same. Presently, there is no theoretical model available which can explain low-energy incomplete fusion data consistently.Methods: The excitation functions of complete and incomplete fusion residues populated in the $^{13}C$+$^{169}\mathrm{Tm}$ system have been measured using the recoil-catcher activation technique followed by offline $\ensuremath{\gamma}$ spectroscopy. The evaporation residues have been identified on the basis of characteristic $\ensuremath{\gamma}$ lines and confirmed through the decay-curve analysis.Results: The excitation functions of $xn$ and $pxn$ channels are found to be in good agreement with the statistical model code pace4; this suggests the population of these channels via complete fusion. Some residues are found to have a contribution from their higher charge isobar precursor decay. The precursor contribution has been deduced from the cumulative cross section using the standard successive radioactive decay formulations. The excitation functions of $\ensuremath{\alpha}$-emitting channels are observed to be significantly enhanced as compared to the statistical model code pace4. This enhancement may be attributed to the contribution from incomplete fusion. The incomplete fusion strength function for $^{13}C$+$^{169}\mathrm{Tm}$ is compared with that obtained in the $^{12}C$+$^{169}\mathrm{Tm}$ system. It has been found that the one-neutron (1$n$) excess projectile $^{13}C$ (as compared to $^{12}C$) results in a less incomplete fusion contribution due to its relatively large negative alpha-$Q$ value. Recently proposed ``alpha-$Q$-value systematics'' seems to explain incomplete fusion data.

Mated progeny production is a biomarker of aging in Caenorhabditis elegans.

The relationships between reproduction and aging are important for understanding the mechanisms of aging and evaluating evolutionary theories of aging. To investigate the effects of progeny production on reproductive and somatic aging, we conducted longitudinal studies of Caenorhabditis elegans hermaphrodites. For mated wild-type animals that were not sperm limited and survived past the end of the reproductive period, high levels of cross-progeny production were positively correlated with delayed reproductive and somatic aging. In this group of animals, individuals that generated more cross progeny also reproduced and lived longer than individuals that generated fewer cross progeny. These results indicate that progeny production does not accelerate reproductive or somatic aging. This longitudinal study demonstrated that cumulative cross progeny production through day four is an early-stage biomarker that is a positive predictor of longevity. Furthermore, in mated animals, high levels of early cross progeny production were positively correlated with high levels of late cross progeny production, indicating that early progeny production does not accelerate reproductive aging. The relationships between progeny production and aging were further evaluated by comparing self-fertile hermaphrodites that generated relatively few self progeny with mated hermaphrodites that generated many cross progeny. The timing of age-related somatic degeneration was similar in these groups, suggesting progeny production does not accelerate somatic aging. These studies rigorously define relationships between progeny production, reproductive aging, and somatic aging and identify new biomarkers of C. elegans aging. These results indicate that some mechanisms or pathways control age-related degeneration of both reproductive and somatic tissues in C. elegans.

Excitation functions for the formation of longer lived isotopes by deuteron irradiation of Europium

Excitation functions for nuclear reactions induced on natural europium targets by energetic deuterons were studied up to 50MeV. A standard stacked foil technique was used for irradiation and high resolution gamma spectrometry was applied for activity assessment. Direct or cumulative cross sections for reaction products with half-life longer than 2h were determined. Reactions leading to the formation of the radionuclides 147,149,151,153Gd, 147,148,149,150m,150g,152m,152g,154gEu, 153Sm and 150Pm were studied. In most cases no earlier data were available in the literature. The new experimental results were compared with values tabulated in the on-line TENDL2011 library.

Dictionaries Construction Using Alternating Projection Method in Compressive Sensing

This letter introduces a novel algorithm to construct sensing and measurement dictionaries in compressive sensing using alternating projection method. The cumulative and mutual cross coherence of the constructed dictionaries are lower than those of Gaussian random dictionary. The concept of General Restricted Isometry Constant (GRIC) is introduced. Low cumulative cross coherence puts bound on GRIC and small GRIC improves successful recovery rate of OMP algorithm. Experiments demonstrate that OMP algorithm performs better using dictionaries constructed by the proposed algorithm than Gaussian random dictionaries and those constructed by Schnass' algorithm.

New measurement of cross sections of evaporation residues from thenatPr+12C reaction: A comparative study on the production of149Tb

Production cross sections of evaporation residues, $^{149}$Tb, $^{150}$Tb, $^{151}$Tb and $^{149}$Gd, have been measured using the stacked foil technique followed by off-line $\gamma$-spectrometry in $^{12}$C induced reactions on naturally abundant mononuclidic praseodymium target in the 44-79 MeV incident energy range. Measured data have been interpreted comparing with previous measurements and theoretical prediction of nuclear reaction model code \textsc{PACE4}. About 5% and 14% of the theoretical cross sections have been measured for $^{149}$Tb and $^{150}$Tb, respectively. The new cross sections of $^{149}$Tb complement those measured earlier by $\alpha$-spectrometry. Cross sections of $^{151}$Tb are comparable to the theory. Cumulative cross section of $^{149}$Gd sheds light on the nuclear reaction mechanism. In addition, a discussion has been made to show the feasibility of producing $^{149}$Tb in $p$- and $\alpha$-induced reactions on gadolinium isotopes.

A Novel Dictionaries Preconditioning Algorithm for Compressive Sensing

A Novel dictionaries preconditioning algorithm for compressive sensing is proposed in this paper. This algorithm uses alternating projection method to construct sensing and measurement dictionaries with low mutual and cumulative cross coherence. The coherence property of the constructed dictionaries is superior to those constructed by Schnass’ method and by Dictionaries Construction algorithm. The complexity and computation amount is lower than Dictionaries Construction algorithm. The constructed dictionaries improve the performance of OMP and SP algorithms.

Preliminary assessment of flying and handling qualities for mini-UAVs

The purpose of this work is to identify some criteria for the evaluation of flying and handling qualities of small scale Unmanned Aerial Vehicles (mini-UAVs). A possible solution for the evaluation of handling qualities is based on the minimization of cumulative cross track error (estimated along a sequence of waypoints) at constant altitude and speed, assuming gradual variation of the control inputs (throttle, elevator and ailerons). A complete parametric analysis of vehicle open loop dynamics is performed for a demonstrative mini-UAV. The flying and handling qualities are assessed implementing the selected platform in a full state flight simulator including a realistic autonomous navigation and control system. Different target paths are considered and a parametric study based on the minimization of the cross track error is presented. A section of conclusions summarizes the key results and presents suggestions for future work.

Low-energy neutral-current neutrino scattering onTe128,130isotopes

Differential, total, and cumulative cross section calculations for neutral current neutrino scattering on $^{128,130}\mathrm{Te}$ isotopes are performed in the context of the quasiparticle random phase approximation by utilizing realistic two-nucleon forces. These isotopes are the main contents of detectors of ongoing experiments with multiple neutrino physics goals (COBRA and CUORE at Gran Sasso), including potential low-energy astrophysical neutrino (solar, supernova, geoneutrinos) detection. The incoming neutrino energy range adopted in our calculations (${\ensuremath{\varepsilon}}_{\ensuremath{\nu}}\ensuremath{\leqslant}100$ MeV) covers the low-energy $\ensuremath{\beta}$-beam neutrinos and the pion-muon stopped neutrino beams existing or planned to be conducted at future neutron spallation sources. The aim of these facilities is to measure neutrino-nucleus cross sections at low and intermediate neutrino energies with the hope of shedding light on open problems in neutrino-induced reactions on nuclei and neutrino astrophysics. Such probes motivate theoretical studies on weak responses of various nuclear systems; thus the evaluated cross sections may be useful in this direction.

Reaction mechanism in the20Ne+59Co system at 3--7 MeV/nucleon, and observation of entrance-channel mass-asymmetry of the incomplete fusion fraction

Incomplete fusion of $^{20}\mathrm{Ne}$ with $^{59}\mathrm{Co}$ has been investigated at 3--7 MeV/nucleon using the measurement and analysis of excitation functions. The recoil-catcher technique followed by offline gamma-ray spectroscopy has been employed. Evaporation residues are found to have contributions from precursor decays, which have been separated out from the measured cumulative cross sections of evaporation residues. Measured independent cross sections are compared with PACE-2 predictions. The PACE-2 calculations are carried out for evaporation residues formed in complete fusion (CF), and the parameters are optimized so as to reproduce the cross section of evaporation residues produced exclusively in CF, e.g., $\mathit{xn}$ and pxn products. With these parameters, the predicted CF cross sections for alpha emission products are calculated. Any substantial enhancement in the experimental cross section over the PACE-2 prediction is taken as a signature of incomplete fusion (ICF). The analysis indicates the occurrence of incomplete fusion involving the breakup of $^{20}\mathrm{Ne}$ into $^{16}\mathrm{O}$ $+$ $^{4}\mathrm{He}$ and/or $^{12}\mathrm{C}$ $+$ $^{8}\mathrm{Be}$(2\ensuremath{\alpha}) followed by fusion of one of the fragments with the target nucleus $^{59}\mathrm{Co}$. These data also suggest that the probability of incomplete fusion increases with the projectile energy. Moreover, the ICF probability is found to increase with entrance-channel mass-asymmetry of the projectile-target systems.

Production of 225Ac and 223Ra by irradiation of Th with accelerated protons

The possibility of producing 225Ac and 223Ra by irradiation of natural 232Th with medium-energy protons was examined. Thorium foils were irradiated with 90-, 110-, and 135-MeV protons at the accelerator of the Institute for Nuclear Research, Russian Academy of Sciences, in Troitsk (Moscow oblast). The cumulative production cross sections for 225Ac were 6.7 ± 0.9, 9.8 ± 1.9, and 13.9 ± 1.5 mb, and for 227Th (223Ra precursor), 43 ± 5, 37 ± 6, and 35 ± 4 mb, respectively. Based on the experimental data and theoretical calculations, the possible yields of 225Ac and 223Ra in irradiation of thick thorium targets at various accelerators were determined. An efficient procedure was suggested for isolating the products from the irradiated targets: 225Ac, by liquid extraction and extraction chromatography, and 223Ra, by sublimation from a thorium-lanthanum melt followed by thermochromatographic separation in metallic titanium columns and extraction-chromatographic isolation of radium. The procedure allows production of large (units of curies) amounts of radiochemically pure 225Ac and 223Ra, which is promising for wide use of these radionuclides in nuclear medicine.

Positron scattering and ionization of neon atoms — theoretical investigations

Although positron scattering with inert gas atoms has been studied in theory as well as in experiment, there are discrepancies. The present work reports all the major total cross sections of e+—neon scattering at incident energies above ionization threshold, originating from a complex potential formalism. Elastic and cumulative inelastic scatterings are treated in the complex spherical e+—atom potential. Our total inelastic cross section includes positronium formation together with ionization and excitation channels in Ne. Because of the Ps formation channel it is difficult to separate out ionization cross sections from the total inelastic cross sections. An approximate method similar to electron—atom scattering has been applied to bifurcate ionization and cumulative excitation cross sections at energies from threshold to 2000 eV. Comparisons of present results with available data are made. An important outcome of this work is the relative contribution of different scattering processes, which we have shown by a bar-chart at the ionization peak.

Instantaneous-shape sampling for calculation of the electromagnetic dipole strength in transitional nuclei

Electromagnetic dipole absorption cross sections of transitional nuclei with large-amplitude shape fluctuations are calculated in a microscopic way by introducing the concept of instantaneous-shape sampling, which is based on slow shape dynamics as compared with fast dipole vibrations. The dipole strength is calculated by means of the quasiparticle random-phase approximation (QRPA) for the instantaneous shapes, the probability of which is obtained by means of the interacting boson approximation. The calculations agree well with the experimental photoabsorption cross sections near the nucleon emission threshold, but they underestimate it at low energies. The cumulative cross sections for the region below the threshold are a factor of 2 too low.

Combined application of computer tomography and light microscopy for analysis of conductive xylem area in coarse roots of European beech and Norway spruce

Axial water transport in trees is mainly deter- mined by the gradient of negative water pressure and the structure of conductive xylem elements (i.e. conduits) con- necting the fine roots with the foliage. There is still an essential lack of knowledge concerning the relationship between wood structure and hydraulic properties, especially of coarse roots. To this end, the study aimed (1) to work out a novel approach, based on the combination of computer tomography (CT) and light microscopy (LM), for determin- ing the cumulative cross-sectional lumen area of conduits involved in the water transport of coarse roots in European beech (Fagus sylvatica) and Norway spruce (Picea abies) and (2) to demonstrate its adequacy in quantifying the functional relationship between sapwood anatomy and ascending water mass flow in the xylem. The cross-sectional sapwood area of coarse roots was assessed through CT. The cumulative cross- sectional lumen area of conduits in the sapwood (i.e. the lumen area of conductive conduits) was measured by LM in combination with interactive image analysis. The new approach was developed with coarse roots of both the tree species growing in a 60-year-old mixed forest in Bavaria, Germany. The combination of the two methods unveiled spruce to possess a distinct sapwood/heartwood boundary in small-diameter roots, whereas such roots of beech reflected a gradual transition zone; only large-diameter roots displayed a distinct boundary in beech. Additionally, the cumulative lumen area of conductive conduits was found to be approxi- mately 12% of the total coarse root cross-sectional area in both the tree species. The new approach of measuring the conductive lumen area of coarse-root conduits yielded levels of specific sap flow (i.e. axial conductivity) that substantially differed from those derived from commonly applied meth- ods, which were based on sap flow per unit of total cross- sectional root area or xylem cross-sectional area of individual roots. The combination of CT and LM will facilitate func- tional comparisons of woody roots differing in diameter and of tree species of different anatomical xylem structure.

Measurement of the W + jet cross section at CDF

A measurement of W->e nu + n-jet cross sections in ppbar collisions at sqrt(s)=1.96 TeV using the Collider Detector at Fermilab in Run II is presented. The measurement is based on an integrated luminosity of 320 pb-1, and includes events with jet multiplicity from >= 1 to >= 4. In each jet multiplicity sample the differential and cumulative cross sections with respect to the transverse energy of the n^(th)-leading jet are measured. For W+>=2 jets the differential cross section with respect to the 2-leading jets invariant mass m_(j_(1)j_(2)) and angular separation Delta R_(j_(1)j_(2)) is also reported. The data are compared to predictions from Monte Carlo simulations.

Measurement of activation cross sections of the proton induced nuclear reactions on palladium

Excitation functions of proton induced reactions on Pd are important for medical radioisotope production, for activation analysis, for development of low activation materials and other purposes. No experimental data exist in the literature for low and medium energy range protons. A detailed study of the excitation functions was performed up to 80 MeV proton energy by using the stacked foil irradiation technique and gamma-ray spectrometry. The irradiations were carried out at the external beam lines of the AVF cyclotron at the Tohoku University. Japan (80 and 70 MeV) and the CGR 560 cyclotron at the Vrije Universiteit Brussels (38, 29 and 17 MeV). The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the parallel measured excitation functions of natAl(p,x)22,24Na and natCu(p,x)56,58Co, 62,65Zn monitor reactions. Excitation functions for direct and cumulative cross sections have been measured for the production of 105mg,106m,110mAg, 101Pd, 101mRh and 97Ru radionuclei. Calculations for the excitation functions using the Alice-IPPE code were performed with a view to estimate the weight of the different contributing reactions and to check the trend and the magnitude of the obtained experimental data.

Simulation of the apparent diffusion of helium-3 in the human acinus

Functional MRI of the lungs with hyperpolarized helium provides an index of apparent diffusion measured over several seconds (ADCsec) that is only 2% of its free diffusion in air (0.88 cm2/s). The potential of ADCsec to noninvasively assess in vivo lung structure of diseased lungs at the length scales corresponding to several seconds is critically dependent on the exact link between ADCsec and lung peripheral structure. To understand the intruigingly small ADCsec, numerical simulations of gas transport were performed in 1) a trumpet model, 2) a symmetrical, and 3) an asymmetrical multiple-branch-point model of the human acinus. For initial gas boluses in different locations of the acinar models, ADCsec was quantified as follows. At different time intervals, we computed a coefficient of variation (CoV) of the concentration distributions within each acinar model. The slope in the semilog plot of log(CoV) vs. time was proportional to the ADCsec generated by the internal model structure, provided that the outer model boundaries were similar across all models (i.e., similar cumulative cross section vs. average path length). The simulations revealed an ADCsec that amounted to approximately 1% of free diffusion in the trumpet model of the acinus, i.e., corresponding to free diffusion within the acinar geometric boundaries. Our simulations show that for initial conditions corresponding to those used in MRI experiments, intra-acinar branching introduces a dramatic diffusion delay, comparable to what is observed experimentally.

Theory of Time-Dependent Reactive Scattering: Cumulative Time-Evolving Differential Cross Sections and Nearside−Farside Analyses of Time-Dependent Scattering Amplitudes for the H + D2 → HD + D Reaction

Nearside-farside (NF) theory, originally developed in the energy domain for the time-independent description of molecular collisions and chemical reactions, is applied to the plane wave packet (PWP) formulation of time-dependent scattering. The NF theory decomposes the partial wave series representation for the time-dependent PWP scattering amplitude into two time-dependent subamplitudes: one N, the other F. In addition, NF local angular momentum (LAM) theory is applied to the PWP scattering amplitude. The novel concept of a cumulative time-evolving differential cross section is introduced, in which the upper infinite time limit of a half-Fourier transform is replaced by a finite time. In a similar way, a cumulative energy-evolving angular distribution is defined. Application is made to the state-to-state reaction, H + D2(v(i) = 0, j(i) = 0) --> HD(v(f) = 3, j(f) = 0) + D, where v(i), j(i) and v(f), j(f) are vibrational and rotational quantum numbers for the initial and final states, respectively. This reaction exhibits time-direct and time-delayed (by about 25 fs) collision mechanisms. It is shown that the direct-time mechanism is N dominant scattering, whereas the time-delayed mechanism exhibits characteristics of NF interference. The NF and LAM theories provide valuable insights into the time-dependent properties of a reaction, as do snapshots from a movie of the cumulative time-evolving differential cross section.