bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of atmospheric humidity and zonal soil water stress on initial growth of planted northern red oak seedlings
Authors: Larson M. M.
Published: February 2009

Northern red oak (Quercusrubra L.) 1-0 seedlings were planted in plastic tubes with a rubber moisture barrier placed around taproots at midpoint so that upper and lower sections of the root system could be independently watered with polyethylene glycol solutions to induce various soil moisture stress conditions. Trees were also grown at two relative humidity (RH) levels.In the first of two studies, soil moisture stress levels were −1/3, −3, −6 bars (1 bar = 105 Pa), and RH's were 75 and 45%. Root regeneration (largely confined to cut end of lower taproot) and top growth decreased, and dieback of planted stems increased, as soil moisture stress of either upper or lower root sections increased. When both sections were −6 bars, root regeneration was nil.In the second study, upper root soil moisture stress levels included a −12-bar treatment which reduced dry weight of leaves and roots to about one-half that of unstressed plants. However, a unit increase in stress to lower root sections was 1.5 to 4 times more inhibitory to growth than a similar stress to upper root sections. Low RH decreased several measures of seedling growth, increased stem dieback, and prolonged time to budbreak from 6 to 12 days for most soil moisture treatments.These studies demonstrate that root regeneration is very sensitive to soil moisture stress on lower roots, where most of the new roots originate, and moderately sensitive to stress on upper roots and to atmospheric stress on shoots.
Short-term impact of a spruce budworm outbreak on a deer wintering area
Authors: Potvin François
Published: February 2009

The impact of the current budworm outbreak on deer (Odocoileusvirginianusborealis Miller) was studied from 1972 to 1979 in a wintering area located at the northern extremity of Témiscouata Lake, Québec. This area encompassed 20 km2 and consisted mostly of balsam fir (Abiesbalsamea (L.) Mill.) and spruce (Piceaglauca (Moench) Voss) stands which suffered high mortality in 1975. The proportion of coniferous cover dropped from 66 to 29% as a result of the outbreak. Nevertheless, the area occupied by deer and the deer population itself remained quite stable. Deer progressively deserted balsam fir - spruce stands and sought shelter in cedar (Thujaoccidentalis L.) stands that are well distributed throughout the study area. Elimination of balsam fir from the shrub layer of the more severely affected stands resulted in a loss of two-thirds of the browse biomass and invasion by raspberry (Rubusidaeus L.). Conversely, tree lichens on dead trees have become an important new food source. The impact of large-scale tree mortality by the budworm in wintering areas sharing the same ecological conditions may depend on the presence or absence of cedar stands as an alternative coniferous cover type.
Cicatrisation et formation de racines adventives sur des boutures de tiges d'épinette de Norvège (Piceaabies (L.) Karst.)
Authors: Girouard Ronald M.
Published: February 2009

A histological study of stem cuttings collected from 4-year-old Piceaabies and planted under intermittent mist, revealed the presence of a closing layer and wound periderm during wound healing and root primordia near leaf traces. No callus tissue was formed. Approximately 14 days after planting, root initiation started in phloem ray parenchyma cells. Root initials divided tangentially or in a slightly oblique plane. After 28 days, root primordia developed when cells divided in various planes. Between the 28th and the 35th day, the morphological differentiation of root primordia began. After 35 days, many primordia possessed an apical meristem, a young rootcap, and the beginning of a vascular cylinder and cortical parenchyma. The roots emerged either through, or a few millimetres above, the basal end of the cuttings. Parenchyma cells located at the proximal end of the roots differentiated into vascular elements and provided a vascular connection between the newly formed organs and the stems.
IMPROVING SUPERVISED LEARNING BY ADAPTING THE PROBLEM TO THE LEARNER
Authors: MENKE JOSHUA , MARTINEZ TONY
Published: February 2009

While no supervised learning algorithm can do well over all functions, we show that it may be possible to adapt a given function to a given supervised learning algorithm so as to allow the learning algorithm to better classify the original function. Although this seems counterintuitive, adapting the problem to the learner may result in an equivalent function that is "easier" for the algorithm to learn. One method of adapting a problem to the learner is to relabel the targets given in the training data. The following presents two problem adaptation methods, SOL-CTR-E and SOL-CTR-P, variants of Self-Oracle Learning with Confidence-based Target Relabeling (SOL-CTR) as a proof of concept for problem adaptation. The SOL-CTR methods produce "easier" target functions for training artificial neural networks (ANNs). Applying SOL-CTR over 41 data sets consistently results in a statistically significant (p < 0.05) improvement in accuracy over 0/1 targets on data sets containing over 10,000 training examples.
SYMMETRY AXIS BASED OBJECT RECOGNITION UNDER TRANSLATION, ROTATION AND SCALING
Authors: HYDER MASHUD , ISLAM MD. MONIRUL , AKHAND M. A. H. , MURASE KAZUYUKI
Published: February 2009

This paper presents a new approach, known as symmetry axis based feature extraction and recognition (SAFER), for recognizing objects under translation, rotation and scaling. Unlike most previous invariant object recognition (IOR) systems, SAFER puts emphasis on both simplicity and accuracy of the recognition system. To achieve simplicity, it uses simple formulae for extracting invariant features from an object. The scheme used in feature extraction is based on the axis of symmetry and angles of concentric circles drawn around the object. SAFER divides the extracted features into a number of groups based on their similarity. To improve the recognition performance, SAFER uses a number of neural networks (NNs) instead of single NN are used for training and recognition of extracted features. The new approach, SAFER, has been tested on two of real world problems i.e., English characters with two different fonts and images of different shapes. The experimental results show that SAFER can produce good recognition performance in comparison with other algorithms.
STOPPED K- PHYSICS WITH FINUDA
Authors:   FOR THE FINUDA COLLABORATION, CAMERINI PAOLO
Published: February 2009

The FINUDA spectrometer is installed at one of the interaction points of the DAΦNE e+e- collider in Frascati(I). By stopping the low energy K - from the ɸ(1020) decays, FINUDA performed a rich program of studies of K- induced interactions on a set of nuclear targets. A survey of the results will be given, with emphasis on the study of non-mesonic weak decays of Λ-hypernuclei and on the search for deeply bound kaonic nuclear clusters.
CUSPS IN THE KAON DECAYS
Authors: RUSETSKY AKAKI
Published: February 2009

We consider two ways of the experimental determination of the S-wave ππ scattering lengths: from K → 3π decays and from Ke4 decays. In both cases the unitary cusps, which emerge due to the difference in the charged and neutral pion masses, play a crucial role. We construct a systematic effective field theory framework which can be used to describe decay amplitudes in the cusp region.
VECTOR MESON PRODUCTION AT HERA
Authors:   FOR THE H1 AND ZEUS COLLABORATIONS, MARAGE PIERRE
Published: February 2009

The rich experimental landscape of exclusive vector meson production at the high energy electron–proton collider HERA is reviewed, with emphasis on the transition from soft to hard diffraction and QCD interpretations.
PHYSICS WITH HADRONIC PROBES AT COMPASS
Authors:   FOR THE COMPASS COLLABORATION, KETZER BERNARD
Published: February 2009

This paper describes the methods and goals of the spectroscopy programme of COMPASS using hadron beams, and reports on first results from a short pilot run using a 190 GeV/c pion beam, carried out in 2004. A partial wave analysis of the reaction π-N → π-π-π+ N' shows significant production of a state with spin-exotic quantum numbers JPC = 1-+ at 1.6 GeV/c2.
CHARM AND CHARMONIUM SPECTROSCOPY AT BELLE
Authors:   FOR THE BELLE COLLABORATION, BRAČKO MARKO
Published: February 2009

The Belle experiment at the KEKB asymmetric-energy e+e- collider provides an excellent environment not only for B physics, but also for studies in charm and charmonium spectroscopy. The paper gives a summary of recent Belle achievements in this field.
CHARM AND CHARMONIUM SPECTROSCOPY AT BABAR
Authors: PALANO ANTIMO
Published: February 2009

We report on the most recent progress in charm and charmonium spectroscopy. Many new states have been discovered in the high statistics data sets from B -factories and CLEO experiment. Some of these particles are candidates for being exotic non [Formula: see text] states. We will concentrate on results obtained at the BABAR experiment which are based on up to ≈ 470 fb-1 of e+e- collisions at the ϒ(4S) resonance at the PEP-II linear accelerator at SLAC.
THE PANDA EXPERIMENT — HADRON PHYSICS WITH ANTIPROTONS AT FAIR
Authors:   FOR THE PANDA COLLABORATION, LANGE JENS SÖREN
Published: February 2009

The PANDA (AntiProton Annihilations at Darmstadt) experiment will investigate [Formula: see text] and [Formula: see text] collisions in the anti-proton beam momentum range pbeam = 1–15 GeV / c , corresponding to a center-of-mass energy of [Formula: see text], at the future FAIR (Facility for Anti-Proton and Ion Research) accelerator complex at GSI, Darmstadt, Germany.
SYNCHRONISATION OF RESONANCES WITH THRESHOLDS
Authors: BUGG DAVID V.
Published: February 2009

The mechanism by which a resonance may be attracted to a sharp threshold is described with several examples. It involves a threshold cusp interfering constructively with either or both (i) a resonance produced via confinement, (ii) attractive t- and u-channel exchanges. More generally, it is suggested that resonances are eigenstates generated by mixing between confined states and long-range meson and baryon exchanges.
SUMMARY OF THE 10-TH INTERNATIONAL WORKSHOP ON MESON PRODUCTION, PROPERTIES AND INTERACTION IN KRAKÓW, POLAND
Authors: FAESSLER AMAND
Published: February 2009

This is a summary of the MESON2008 workshop in Kraków. The original powerpoint summary with all the figures can be found on the conference webpage and in the proceedings of the original talks in this volume. These Proceedings of the summary will therefore not contain the original figures which can be looked up at the two locations mentioned.
DYNAMICS OF STRONG AND RADIATIVE DECAYS OF Ds MESONS
Authors: SOYEUR MADELEINE , LUTZ MATTHIAS F. M.
Published: February 2009

The positive parity scalar [Formula: see text] and axial-vector [Formula: see text] charmed strange mesons are generated by coupled-channel dynamics through the s-wave scattering of Goldstone bosons off the pseudoscalar and vector D ( D s)-meson ground states. The attraction leading to the specific masses of these states reflects the chiral symmetry breaking scale which characterizes the Weinberg-Tomozawa interaction in the chiral Lagrangian. Chiral corrections to order [Formula: see text] are calculated and found to be small. The [Formula: see text] and [Formula: see text] mesons decay either strongly into the isospin-violating π0 D s and [Formula: see text] channels or electromagnetically. We show that the π0-η and ( K 0 D +- K + D 0) mixings act constructively to generate strong widths of the order of 140 keV. The one-loop contribution to the radiative decay amplitudes of scalar and axial-vector states is calculated using the electromagnetic Lagrangian to chiral order [Formula: see text]. We show the importance of taking into account processes involving light vector mesons explicitly in the dynamics of electromagnetic decays to obtain a satisfactory description of the available data.
DYNAMICAL CALCULATIONS OF $\bar K$ AND MULTI-$\bar K$ NUCLEI
Authors: GAZDA D. , MAREŠ J. , FRIEDMAN E. , GAL A.
Published: February 2009

We report on our recent calculations of [Formula: see text] and multi–[Formula: see text] nuclei. Calculations were performed fully self-consistently across the periodic table using the relativistic mean-field approach. We aimed at detailed analysis of dynamical processes and various thresholds that determine the K- absorption width. Further, we studied the behavior of the nuclear medium under the influence of increasing strangeness in order to search for [Formula: see text] condensation precursor phenomena. Last, we explored possibly self-bound strange hadronic configurations consisting of neutrons and [Formula: see text] mesons and studied their properties.
η PRODUCTION IN PROTON-PROTON COLLISIONS AT 72 MeV EXCESS ENERGY
Authors:   FOR THE CELSIUS/WASA COLLABORATION, PETTERSSON H. , BASHKANOV M. , BOGOSLOWSKY D. , CALÉN H. , CLEMENT H. , EKSTRÖM C. , FRANSSON K. , GUSTAFSSON L. , HÖISTAD B. , IVANOV G. , JACEWICZ M. , JIGANOV E. , JOHANSSON T. , KELETA S. , KHAKIMOVA O. , KOCH I. , KREN F. , KULLANDER S. , KUPŚĆ A. , KUZNETSOV A. , MARCINIEWSKI P. , MEIER R. , MOROSOV B. , PAULY C. , PETUKHOV Y. , POVTOREJKO A. , RUBER R. J. M. Y. , SCHÖNNING K. , SCOBEL W. , SHWARTZ B. , SKORODKO T. , SOPOV V. , STEPANIAK J. , THÖRNGREN-ENGBLOM P. , TIKHOMIROV V. , TUROWIECKI A. , WAGNER G. J. , WOLKE M. , YAMAMOTO A. , ZABIEROWSKI J. , ZŁOMANĆZUK J.
Published: February 2009

The production of η mesons at an excess energy of 72 MeV has been studied in the reaction pp → pp(η)γγ. It is shown that a simple model with Pp final states included reproduces observed differential distributions better than the same model restricted to Ss , Sd and Ds final states. The strong influence of the Pp states could be taken as an indication of ρ dominance within an one boson exchange model for the excitation of N *(1535).
EMC STUDIES USING THE SIMULATION FRAMEWORK OF PANDA
Authors:   FOR THE PANDA COLLABORATION, BIEGUN ALEKSANDRA
Published: February 2009

The Anti-Proton ANnihilation at DArmstadt (PANDA) experiment proposed at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt (Germany) will perform a high-precision spectroscopy of charmonium and exotic hadrons, such as hybrids, glueballs and hypernuclei. A highly intense beam of anti-protons provided by High Energy Storage Ring (HESR) with an unprecedented resolution will scan a mass range of 2 to 5.5 GeV/c2.

In preparation for experiments with PANDA, careful and large-scale simulation studies need to be performed in the coming years to determine analysis strategies, to provide feedback for the design, construction and performance optimisation of individual detector components and to design methods for the calibration and interpretation of the experimental results. Results of a simulation for the ElectroMagnetic Calorimeter (EMC), built from lead tungstate (PWO) crystals and placed inside the Target Spectrometer (TS), are presented. The simulations were carried out using the PandaRoot framework, which is based on ROOT and being developed by the PANDA collaboration.
FORWARD SPECTROMETER OF PANDA — REQUIREMENTS AND SOLUTIONS
Authors:   FOR THE PANDA COLLABORATION, WROŃSKA ALEKSANDRA
Published: February 2009

PANDA is a future antiproton experiment designed to study fundamental questions of hadron and nuclear physics. It will work as a fixed-target facility, hence – due to the Lorentz boost – the distribution of reaction products will be strongly forward-peaked, in particular for the near-threshold measurements. Thus, the Forward Spectrometer, covering the most forward angles (θlab < 10°) is one of the key components of PANDA.

In this contribution, current design of the Forward Spectrometer is presented. Spectrometer components, including dipole magnet, tracking detectors, electromagnetic and hadron calorimeter, muon counters, RICH detector and TOF system are discussed. Results of simulations are shown along with tests of the prototype detectors performed in a high-rate environment.
EXCLUSIVE J/ψ PHOTOPRODUCTION IN pp AND $p\bar p$ COLLISIONS
Authors: SCHÄFER WOLFGANG , RYBARSKA ANNA , SZCZUREK ANTONI
Published: February 2009

We report on a detailed investigation of exclusive J/ψ production in proton–proton and proton–antiproton collisions. Predictions for Tevatron and LHC energies are included.
MESON PRODUCTION FROM DIFFRACTIVE PION DISSOCIATION AT COMPASS
Authors:   FOR THE COMPASS COLLABORATION, WEITZEL QUIRIN
Published: February 2009

Diffractive dissociation reactions at COMPASS provide clean access to mesons with masses below ≈ 2.5 GeV /c2. This paper presents a partial wave analysis of about 420 000 π- Pb → π-π-π+ Pb events at 190 GeV/c beam momentum and with four-momentum transfer t' ∈ [0.1,1] GeV 2/c2. The well-known a1(1260), a2(1320) and π2(1670) mesons are resolved with high quality. Also the less established states π(1800) and a4(2040) are seen. In addition, a resonance in the spin-exotic JPC = 1-+ wave is observed. A mass-dependent fit results in a mass and width of [Formula: see text] and [Formula: see text], respectively, which is consistent with the disputed hybrid candidate π1(1600).
RECENT NA48/2 RESULTS ON Ke4 AND K3π DECAYS AND DETERMINATION OF THE ππ SCATTERING LENGTHS
Authors:   FOR THE NA48/2 COLLABORATION, BIZZETI ANDREA
Published: February 2009

Large samples of K± → 3π and K± → π+π-e±ν (Ke4) decays have been collected by the NA48/2 experiment at CERN SPS.

At the π+π- threshold, the π0π0 invariant mass spectrum of the decay K± → π±π0π0 xhibits a Wigner cusp, from which the S-wave ππ scattering lengths are extracted with high precision.

The same scattering lengths are also independently determined from the accurate measurement of the form factors in the Ke4 decay K± → π+π-e±ν.
VISCOSITY OF QUARK PLASMA
Authors: CZERSKI PIOTR
Published: February 2009

The quark viscosity in the quark gluon plasma is evaluated in Hard Thermal Loop (HTL) approximation. The different contributions to the viscosity arising from the various components of the quark spectral function are discussed.
SEMILEPTONIC DECAYS OF HEAVY MESONS AT RHIC
Authors: ŁUSZCZAK MARTAL , MACIUŁA RAFAŁ , SZCZUREK ANTONI
Published: February 2009

We discuss production of nonphotonic electrons in proton-proton scattering at RHIC. The distributions in rapidity and transverse momentum of charm and bottom quarks/antiquarks are calculated in the kt-factorization approach. The hadronization of heavy quarks is done by means of Peterson and Braaten et al. fragmentation functions. The semileptonic decay functions are found by fitting recent semileptonic data obtained by the CLEO and BABAR collaborations.
ANALYZING POWERS MEASUREMENT FOR d - p ELASTIC SCATTERING AT THE INTERNAL TARGET STATION OF NUCLOTRON
Authors: KURILKIN P. K. , SUDA K. , UESAKA T. , LADYGIN V. P. , GURCHIN YU. V. , YU. ISUPOV A. , ITOH K. , JANEK M. , KARACHUK J.-T. , KAWABATA T. , KHRENOV A. N. , KISELEV A. S. , KIZKA V. A. , KLIMAN J. , KRASNOV V. A. , LADYGINA N. B. , LIVANOV A. N. , MAEDA Y. , MALAKHOV A. I. , MATOUCEK V. , MORHAC M. , REZNIKOV S. G. , SAKAGUCHI S. , SAKAI H. , SASAMOTO Y. , SEKIGUCHI K. , SHIKHALEV M. A. , TURZO I. , VASILIEV T. A. , WITAŁA H.
Published: February 2009

Analyzing powers measurement Ay, Ayy and Axx for the d - p elastic scattering were performed at the Internal Target Station of Nuclotron at JINR at Ed = 880 and 2000 MeV. These data are necessary to obtain the information on the 3NF structure and the relativistic effects. They are also important for development of the efficient deuteron beam polarimetry at high energies.

The results of the analyzing powers at Ed = 880 MeV covered the angular range from 60 to 140° in the c.m.s. are compared with several theoretical calculations.

The preliminary data on the analyzing powers measurement Ay, Ayy at Ed = 2000 MeV are discussed.
INSIGHTS INTO THE π-p → ηn REACTION MECHANISM
Authors: DURAND J. , JULIA-DIAZ B. , LEE T.-S. H. , SAGHAI B. , SATO T.
Published: February 2009

A dynamical coupled channels formalism is used to investigate the η–meson production mechanism on the proton induced by pions, in the total center-of-mass energy region from threshold up to 2 GeV. We show how and why studying exclusively total cross section data might turn out to be misleading in pinning down the reaction mechanism.
Φ PRODUCTION IN pp COLLISIONS
Authors: SIBIRTSEV ALEXANDER
Published: February 2009

The data for near-threshold cross section for the reaction pp → ppɸ published by the DISTO and ANKE Collaboration are analyzed in order to evaluate the OZI ratio at low energies by taking into account corrections from the kinematics and the final-state interaction. Combining these new data with the few measurements available at higher energies the limit for the OZI rule violation is evaluated and the possible contribution from a five-quark baryonic resonance coupled to the ɸp system is estimated.
a0(980) AND f0(980) MESONS AS HADRONIC MOLECULES
Authors: BRANZ T. , GUTSCHE T. , LYUBOVUTSKIJ V. E.
Published: February 2009

We discuss a possible interpretation of the scalar mesons f0(980) and a0(980) as hadronic molecules - bound states of K and [Formula: see text] mesons. Using a phenomenological Lagrangian approach we calculate strong as well as the electromagnetic decay properties of both scalars. The covariant and gauge invariant model, which also allows for finite size effects of the hadronic molecule, delivers results in good agreement with experimental data.
DIELECTRON MEASUREMENTS IN NN INTERACTIONS AT A BEAM ENERGY OF 1.25 GeV WITH HADES
Authors:   FOR THE HADES COLLABORATION, GALATYUK TETYANA
Published: February 2009

The dielectron yield in pp and dp reactions at a beam kinetic energy of 1.25 GeV/u has been measured using the HADES spectrometer at GSI. In proton-proton reactions the most abundant source above the π0 Dalitz region is expected to be Δ Dalitz decay. The obsearved large difference in dielectron production in pp and dp systems suggests that dielectron production in the dp system is dominated by a np process. In order to separate Δ Dalitz decays and np bremsstrahlung we compare the dielectron yield observed in pp with the one of dp reactions measured at the same beam energy.
DIELECTRON PRODUCTION IN Ar+KCl AT 1.756 AGeV WITH HADES
Authors:   FOR THE HADES COLLABORATION (The full author list is given in HADES Meson 2008 plenary talk by I. Froehlich.), KŘÍŽEK FILIP
Published: February 2009

The HADES collaboration studied dielectron production in C + C , p + p , and d + p reactions, with the main goal to investigate properties of vectors mesons through their dielectron decay. Production of e+e- pairs in Ar + KCl collisions at a beam energy of 1.756 A GeV was measured recently by the collaboration and preliminary results of the experimental data analysis will be reported. Pair spectra will be compared with a prediction of a thermal model based on the Monte Carlo event generator Pluto.
MEASUREMENT OF POLARISATION TRANSFER IN HYPERON PHOTOPRODUCTION AT MAMI
Authors:   FOR THE CRYSTALBALL@MAMI AND A2 COLLABORATIONS, JUDE T. C. , GLAZIER D. I. , WATTS D. P.
Published: February 2009

The photoproduction of K+ mesons is an important challenge to recent QCD based chiral perturbation theories in the strange quark sector and is an important constraint on the nucleon excitation spectrum. We present preliminary data from a new high precision measurement using the Crystal Ball detector. The measurement pioneers a new technique for tagging strangeness using detailed cluster analysis in segmented calorimeters which has potential wider application at present and future hadron physics facilities.
ALPHA-DECAYS TO MEMBERS OF GROUND-STATE ROTATIONAL BAND OF HEAVY EVEN-EVEN NUCLEI
Authors: XU CHANG , REN ZHONGZHOU
Published: February 2009

We apply a simple barrier penetration approach to calculate α-decay branching ratios to members of ground-state rotational band of heavy even-even nuclei. The influence of α-decay energy, the angular momentum of α-particle, and the excitation probability of the daughter nucleus is taken into account in our calculations. The theoretical branching ratios of α-transitions are found to agree with the available experimental data well.
REVIEW ON THEORETICAL RESEARCHES OF SUPERHEAVY NUCLEI
Authors: REN ZHONGZHOU , DONG TIEKUANG , XU CHANG , CHEN DINGHAN
Published: February 2009

We review the recent progress of theoretical researches on heavy nuclei and superheavy nuclei. At first we analyze the experimental data of long lifetime heavy nuclei and discuss their stability. Then the calculated binding energies and alpha-decay energies of heavy and superheavy nuclei from different models are compared and discussed. This includes the results from the local binding energy formula of heavy nuclei with Z ≥ 90 and N ≥ 130, those from the relativistic mean-field model, and from other models. For the local binding energy formula, it can reproduce experimental binding energies of known heavy and superheavy nuclei well. The relativistic mean-field model and non-relativistic mean-field model show that there is shape coexistence in superheavy nuclei. For some superheavy nuclei, superdeformed prolate shape can be their ground states and there are isomers in lowly excited states due to shape coexistence. The properties of some unknown superheavy nuclei are predicted. Some new views on the stability and on half-lives of heavy and superheavy nuclei are presented. Possible new phenomenon in superheavy region is analyzed and discussed.
NUCLEAR HALO AND ITS SCALING LAWS IN THE EXCITED STATES OF NUCLEI NEAR THE β-STABILITY LINE
Authors: CHEN J. G. , CAI X. Z. , SHI Y. , MA Y. G. , REN Z. Z. , FANG D. Q. , GUO W. , WANG H. W. , TIAN W. D. , SHEN W. Q.
Published: February 2009

The excited states of some odd A nuclei near the stability line have been systematically investigated from light to intermediate mass with the spherical relativistic mean field (RMF) model. The ratio between the valence nucleon root-mean-square (RMS) radius and the core rms radius, the separation energy and the density distribution have been deduced as signatures for halo or skin structure. We have presented the scaling laws of the ratio of valence particle rms radii and square-potential radii versus the scaled separation energies. The probability for a valence particle being out of the binding potential has also been extracted. We proposed a relaxed necessary condition for nuclear halo occurrence.
ISOSPIN DEPENDENCE OF REACTIONS48Ca+243-251Bk
Authors: SHEN CAIWAN , ABE YASUHISA , BOILLEY DAVID , KOSENKO GRIGORY , ZHAO ENGUANG
Published: February 2009

The fusion process of48Ca induced reactions is studied with the two-step model. In this model, the fusion process is devided into two stages: first, the sticking stage where projectile and target come to the touching point over the Coulomb barrier from infinite distance, and second, the formation stage where the di-nucleus formed with projectile and target evolve to form the spherical compound nucleus from the touching point. By the use of the statistical evaporation model, the residue cross sections for different neutron evaporation channels are analyzed. From the results, optimum reactions are given to synthesize Z=117 element with48Ca induced reactions.
SHELL CORRECTION ENERGY AND THE ENTRANCE CHANNEL EFFECT ON THE FORMATION OF SUPERHEAVY NUCLEI
Authors: BIAN BAO-AN , ZHANG FENG-SHOU , DU SAI-SAI
Published: February 2009

Based on the improved isospin dependent molecular dynamics model in which the shell correction energy of the system is calculated by using deformed two-center shell model and the surface energy of the system is improved by introducing a switch function that combines the surface energies of projectile and target with the one of the compound nucleus. The effects of the shell correction energy on synthesis of superheavy nuclei and the fusion cross sections in asymmetric and nearly symmetric reaction systems leading to the same compound nuclei 62 Zn , 76 Kr , and 202 Pb are studied. The entrance channel mass asymmetry dependence of compound nucleus formation is found by analyzing the shell correction energies, Coulomb barriers and fusion cross sections. The experimental data are described quantitatively by the present model. It is found that the compound nucleus formation is favorable for the systems with larger mass asymmetry.
AB INITIO NO CORE METHODS: APPLICATIONS TO LIGHT NUCLEI
Authors: VARY JAMES P. , MARIS PIETER , SHIROKOV ANDREY
Published: February 2009

We introduce a no-core full configuration (NCFC) approach and present results for 4 He , 12 C , 14 F and some other nuclei with the realistic NN interaction, JISP16. We obtain ground state energies and their uncertainties through exponential extrapolations that we demonstrate are reliable in 4 He where fully converged results are obtained. We find 12 C is overbound by 1.7 MeV and we predict the yet-to-be-measured binding energy of 14 F to be 70.2±3.5 MeV. The extrapolated spectrum of 14 F is in reasonable agreement with known features of the 14 B spectrum. Distinctions are drawn between this approach and the no-core shell model (NCSM).
PROPERTIES OF NUCLEI AND HYPERNUCLEI WITH THE DEFORMED SKYRME HARTREE-FOCK MODEL
Authors: ZHOU XIAN-RONG , SCHULZE H.-J. , SAGAWA H.
Published: February 2009

The isotope dependence of the deformation in carbon and neon isotopes is studied in deformed Skyrme Hartree–Fock model. We find that the deformations of C and Ne isotopes have a strong isotope dependence as a manisfestation of spontaneous breaking effect in nuclear physics. By extending the deformed Skyrme Hartree–Fock model, we studied the properties of Λ hypernuclei in a broad mass region. The results suggest that the core nuclei and the corresponding hypernuclei have similar deformations with the same sign. Some light single-Λ hypernuclei are substantially deformed and the Λ binding energy is modified by the deformation.
PARTICLE-NUMBER CONSERVING TREATMENT FOR THE GROUND STATE BANDS IN EVEN-EVEN TRANSFERMIUM NUCLEI
Authors: HE XIAO-TAO , REN ZHONG-ZHOU
Published: February 2009

The ground state bands observed in even-even transfermium nuclei 250 Fm and 252,254 No are investigated by the cranked shell model with the particle-number conserving treatment for the monopole and quadrupole pairing correlations. The experimental variations of the kinematic moment of inertia with rotational frequency are reproduced very well in our calculation. Our results show bankbendings of [Formula: see text] at ħω ≈ 0.275 and 0.300 MeV in 252 No and 254 No , respectively. The detailed information about the contribution to alignment from each cranked single particle level exhibits that the backbending is mainly due to the rapidly aligned angular momentum of proton 1j15/2 [770]1/2 pairs and neutron 2h11/2 [761]3/2, 1j15/2 [734]9/2 pairs the band crossing.
REGULAR STRUCTURE OF LOW-LYING STATES FOR ATOMIC NUCLEI UNDER RANDOM INTERACTIONS
Authors: ZHAO Y. M.
Published: February 2009

In this paper we review regularities of low-lying states for many-body systems, in particular, atomic nuclei, under random interactions. We shall discuss the famous problem of spin zero ground state dominance, positive parity dominance, collective motion, odd-even staggering, average energies, etc., in the presence of random interactions.
SPECTRAL DISTRIBUTION ANALYSIS OF RANDOM INTERACTIONS WITH J-SYMMETRY AND ITS EXTENSIONS
Authors: KOTA V. K. B. , VYAS MANAN , MAYYA K. B. K.
Published: February 2009

Spectral distribution theory, based on average-fluctuation separation and trace propagation, is applied in the analysis of some properties of a system of m (identical) nucleons in shell model j-orbits with random interactions preserving angular momentum J-symmetry. Employing the bivariate Gaussian form with Edgeworth corrections for fixed E (energy) and M (Jz eigenvalue) density of states ρ(E,M), analytical results, in the form of expansions to order [J(J+1)]2, are derived for energy centroids Ec(m,J) and spectral variances σ2(m,J). They are used to study distribution of spectral widths, J=0 preponderance in energy centroids, lower order cross correlations in states with different J's and so on. Also, an expansion is obtained for occupation probabilities over spaces with fixed M. All the results obtained with spectral distribution theory compare well with those obtained recently using quite different methods. In addition, using trace propagation methods, a regular feature, that they are nearly constant, of spectral variances generated by random interactions is demonstrated using several examples. These open a new window to study regular structures generated by random interactions.
CORRELATION BETWEEN EIGENVALUES AND SORTED DIAGONAL MATRIX ELEMENTS OF A LARGE DIMENSIONAL MATRIX
Authors: ARIMA AKITO
Published: February 2009

Functional dependences of eigenvalues as functions of sorted diagonal elements are given for realistic nuclear shell model (NSM) hamiltonian, the uniform distribution hamiltonian and the GOE hamiltonian. In the NSM case, the dependence is found to be linear. We discuss extrapolation methods for more accurate predictions for low-lying states.
ROBUSTNESS OF STRONG CORRELATION BETWEEN EIGENVALUES AND DIAGONAL MATRIX ELEMENTS
Authors: ZHANG L. H. , SHEN J. J. , LEI Y. , ZHAO Y. M.
Published: February 2009

In this paper we study robustness of strong correlation between eigenvalues and diagonal matrix elements sorted from the smallest to the largest, in the presence of large single-particle splittings for both realistic and schematic systems. We also study the nearest level spacing distribution obtained by the linear correlation.
THE ART OF PREDICTING NUCLEAR MASSES
Authors: HIRSCH JORGE G. , MORALES IRVING , MENDOZA-TEMIS JOEL , FRANK ALEJANDRO , LOPEZ-VIEYRA JUAN CARLOS , BAREA JOSE , PITTEL STUART , VAN ISACKER PIET , VELAZQUEZ VICTOR
Published: February 2009

A review of recent advances in the theoretical analysis of nuclear mass models and their predictive power is presented. After introducing two tests which probe the ability of nuclear mass models to extrapolate, three models are analyzed in detail: the liquid drop model (LDM), the liquid drop model plus empirical shell corrections (LDMM) and the Duflo–Zuker mass formula (DZ). The DZ model is exhibited as the most predictive model. The Garvey–Kelson mass relations are also discussed. It is shown that their fulfillment probes the consistency of the most commonly used mass formulae, and that they can be used in an iterative process to predict nuclear masses in the neighborhood of nuclei with measured masses, offering a simple and reproducible procedure for short range mass predictions.
Effects of thapsigargin and phenylephrine on calcineurin and protein kinase C signaling functions in cardiac myocytes
Authors: Prasad Anand Mohan , Inesi Giuseppe
Published: February 2009

Neonatal rat cardiac myocytes were exposed to 10 nM thapsigargin (TG) or 20 μM phenylephrine (PE) to compare resulting alterations of Ca2+ homeostasis. Either treatment results in resting cytosolic [Ca2+] rise and reduction of Ca2+ signals in myocytes following electrical stimuli. In fact, ATP-dependent Ca2+ transport is reduced due to catalytic inhibition of sarcoplasmic reticulum ATPase (SERCA2) by TG or reduction of SERCA2 protein expression by PE. A marked rise of nuclear factor of activated T cells (NFAT)-dependent expression of transfected luciferase cDNA is produced by TG or PE, which is dependent on increased NFAT dephosphorylation by activated calcineurin (↑CN) and reduced phosphorylation by inactivated glycogen synthase kinase 3β (↓GSK3β). Expression of SERCA2 (inactivated) protein is increased following exposure to TG, whereas no hypertrophy is produced. On the contrary, SERCA2 expression is reduced, despite high CN activity, following protein kinase C (PKC) activation by PE (or phorbol 12-myristate 13-acetate) under conditions producing myocyte hypertrophy. Both effects of TG and PE are dependent on NFAT dephosphorylation by CN, as demonstrated by CN inhibition with cyclosporine (CsA). However, the hypertrophy program triggered by PKC activation bypasses SERCA2 transcription and expression due to competitive recruitment of NFAT and/or other transcriptional factors. A similar dependence on CN activation, but relative reduction under conditions of PKC activation, involves transcription and expression of the Na+/Ca2+ exchanger-1. On the other hand, significant upregulation of transient receptor potential channel proteins is noted following PKC activation. The observed alterations of Ca2+ homeostasis may contribute to development of contractile failure.
Deletion of the serotonin transporter in rats disturbs serotonin homeostasis without impairing liver regeneration
Authors: Matondo Ramadhan B. , Punt Carine , Homberg Judith , Toussaint Mathilda J. M. , Kisjes Ronald , Korporaal Suzanne J. A. , Akkerman Jan Willem N. , Cuppen Edwin , de Bruin Alain
Published: February 2009

The serotonin transporter is implicated in the uptake of the vasoconstrictor serotonin from the circulation into the platelets, where 95% of all blood serotonin is stored and released in response to vascular injury. In vivo studies indicated that platelet-derived serotonin mediates liver regeneration after partial hepatectomy. We have recently generated serotonin transporter knockout rats and demonstrated that their platelets were almost completely depleted of serotonin. Here we show that these rats exhibit impaired hemostasis and contain about 1–6% of wild-type serotonin levels in the blood. Despite the marked reduction of serotonin levels in blood and platelets, efficient liver regeneration and collagen-induced platelet aggregation occur in rats lacking the serotonin transporter. These results provide evidence that liver regeneration is not dependent on the release of serotonin from platelets. Our findings indicate that very low levels of serotonin in blood are sufficient for liver regeneration.
Maternal obesity is necessary for programming effect of high-fat diet on offspring
Authors: White Christy L. , Purpera Megan N. , Morrison Christopher D.
Published: February 2009

We tested the hypothesis that maternal consumption of dietary fat, independent from obesity, increases serum leptin in neonatal pups and predisposes them to adult obesity. Female rats either were fed a high-fat (HF) diet or a low-fat (LF) diet or were fed the HF diet but pair fed (PF) to the caloric intake of the LF group for 4 wk before breeding and throughout gestation and lactation. Dams consuming the HF diet had increased adiposity and were hyperphagic. At weaning, pups born to obese dams had significantly higher body fat and serum leptin levels and reduced insulin tolerance compared with offspring of LF-fed dams. Pups were weaned onto a chow diet until 8 wk of age, when they were then fed either HF or LF diet. At 18 wk of age, offspring from obese HF dams weighed more than offspring from nonobese LF or PF dams, and offspring eating HF diet weighed significantly more than those eating LF diet. Consequently, HF-fed offspring of obese HF dams weighed the most and LF-fed offspring from obese HF dams were similar in weight to HF-fed offspring from nonobese LF dams. These data suggest that maternal obesity exerts an independent effect on offspring body weight that is of similar magnitude as the effect of the offspring's adult diet. Furthermore, there was no difference in body weight between the nonobese LF and PF offspring on either diet. Together, these data suggest that maternal adiposity, and not dietary fat per se, induces hyperleptinemia and insulin resistance in offspring, as well as an increased body weight that persists into adulthood.
Effect of maternal nutrient restriction from early to midgestation on cardiac function and metabolism after adolescent-onset obesity
Authors: Chan L. L. Y. , Sébert S. P. , Hyatt M. A. , Stephenson T. , Budge H. , Symonds M. E. , Gardner D. S.
Published: February 2009

Maternal nutrient restriction (NR) from early to midgestation has marked effects on endocrine sensitivity and organ function of the resulting offspring. We hypothesized that early NR may reset the expression profile of genes central to myocardial energy metabolism, influencing ectopic lipid deposition and cardiac function in the obese adult offspring. NR offspring were exposed to an “obesogenic” environment, and their cardiac function and molecular indexes of myocardial energy metabolism were assessed to explore the hypothesis that an obese individual's risk of heart disease may be modified after maternal NR. Pregnant sheep were fed 100% (control) or 50% (NR) energy requirement from days 30 to 80 of gestation and 100% energy requirement thereafter. At weaning, offspring were exposed to an obesogenic environment or remained lean. At ∼1 yr of age, the hemodynamic response of these offspring to hypotension, together with left ventricular expression profiles of fatty acid-binding protein 3 (FABP3), peroxisome proliferator-activated receptor-γ (PPARγ) and its coactivator (PGC)-1α, acetyl-CoA carboxylase (ACC), AMP-activated protein kinase (AMPK)-α2, and voltage-dependent anion channel 1 (VDAC1), was determined. Obesity produced left ventricular hypertrophy in all animals, with increased ectopic (myocardial) lipid in NR offspring. Obesity per se significantly reduced myocardial transcript expression of PGC-1α, AMPKα2, VDAC1, and ACC and increased expression of PPARγ and FABP3. However, although NR animals were similarly obese, their transcript expression of ACC, PPARγ, and FABP3 was similar to that of lean animals, indicating altered cardiac energy metabolism. Indeed, blunted tachycardia and an amplified inotropic response to hypotension characterized cardiac function in obese NR offspring. The results suggest that maternal NR during early organogenesis can precipitate an altered myocardial response to hypotension and increased myocardial lipid deposition in the adult offspring after adolescent-onset obesity, potentially rendering these individuals more at risk of early heart failure as they age.
Soluble HB-EGF induces epithelial-to-mesenchymal transition in inner medullary collecting duct cells by upregulating Snail-2
Authors: Smith James P. , Pozzi Ambra , Dhawan Punita , Singh Amar B. , Harris Raymond C.
Published: February 2009

Animal models of acute renal injury suggest that the epidermal growth factor receptor (EGFR) axis may have a beneficial role in the recovery from acute renal injury, but recent reports describe detrimental effects of EGFR activation in chronic renal injury. Expression of the EGFR ligand heparin-binding EGF-like growth factor (HB-EGF) increases following renal injury, but the effects of this sustained upregulation have not been well studied. Here, stable overexpression of soluble HB-EGF (sHB-EGF) in mouse inner medullary collecting duct (IMCD) cells led to marked phenotypic changes: sHB-EGF-expressing cells demonstrated a fibroblast-like morphology, did not form epithelial sheets, exhibited cytoplasmic projections, decreased expression of epithelial markers, and increased expression of fibroblast-specific protein-1. They also demonstrated anchorage-independent growth and formed tumors when injected subcutaneously into nude mice. Quantitative RT-PCR and a luciferase reporter assay suggested that sHB-EGF repressed transcription of E-cadherin, and a concomitant TGF-β-independent upregulation of the E-cadherin repressor Snail-2 was observed. Stable downregulation of Snail-2 in sHB-EGF-overexpressing cells restored epithelial characteristics (E-cadherin and cytokeratin expression) but did not alter their anchorage-independent growth. In summary, sustained exposure to sHB-EGF induces epithelial-to-mesenchymal transition of IMCD cells, in part by upregulating the E-cadherin transcriptional repressor Snail-2.
Attenuated, flow-induced ATP release contributes to absence of flow-sensitive, purinergic Cai2+signaling in human ADPKD cyst epithelial cells
Authors: Xu Chang , Shmukler Boris E. , Nishimura Katherine , Kaczmarek Elzbieta , Rossetti Sandro , Harris Peter C. , Wandinger-Ness Angela , Bacallao Robert L. , Alper Seth L.
Published: February 2009

Flow-induced cytosolic Ca2+Cai2+signaling in renal tubular epithelial cells is mediated in part through P2 receptor (P2R) activation by locally released ATP. The ability of P2R to regulate salt and water reabsorption has suggested a possible contribution of ATP release and paracrine P2R activation to cystogenesis and/or enlargement in autosomal dominant polycystic kidney disease (ADPKD). We and others have demonstrated in human ADPKD cyst cells the absence of flow-induced Cai2+signaling exhibited by normal renal epithelial cells. We now extend these findings to primary and telomerase-immortalized normal and ADPKD epithelial cells of different genotype and of both proximal and distal origins. Flow-induced elevation of Cai2+concentration ([Ca2+]i) was absent from ADPKD cyst cells, but in normal cells was mediated by flow-sensitive ATP release and paracrine P2R activation, modulated by ecto-nucleotidase activity, and abrogated by P2R inhibition or extracellular ATP hydrolysis. In contrast to the elevated ATP release from ADPKD cells in static isotonic conditions or in hypotonic conditions, flow-induced ATP release from cyst cells was lower than from normal cells. Extracellular ATP rapidly reduced thapsigargin-elevated [Ca2+]iin both ADPKD cyst and normal cells, but cyst cells lacked the subsequent, slow, oxidized ATP-sensitive [Ca2+]irecovery present in normal cells. Telomerase-immortalized cyst cells also exhibited altered CD39 and P2X7 mRNA levels. Thus the loss of flow-induced, P2R-mediated Cai2+signaling in human ADPKD cyst epithelial cells was accompanied by reduced flow-sensitive ATP release, altered purinergic regulation of store-operated Ca2+entry, and altered expression of gene products controlling extracellular nucleotide signaling.
Nuclear angiotensin II type 2 (AT2) receptors are functionally linked to nitric oxide production
Authors: Gwathmey TanYa M. , Shaltout Hossam A. , Pendergrass Karl D. , Pirro Nancy T. , Figueroa Jorge P. , Rose James C. , Diz Debra I. , Chappell Mark C.
Published: February 2009

Expression of nuclear angiotensin II type 1 (AT1) receptors in rat kidney provides further support for the concept of an intracellular renin-angiotensin system. Thus we examined the cellular distribution of renal ANG II receptors in sheep to determine the existence and functional roles of intracellular ANG receptors in higher order species. Receptor binding was performed using the nonselective ANG II antagonist125I-[Sar1,Thr8]-ANG II (125I-sarthran) with the AT1antagonist losartan (LOS) or the AT2antagonist PD123319 (PD) in isolated nuclei (NUC) and plasma membrane (PM) fractions obtained by differential centrifugation or density gradient separation. In both fetal and adult sheep kidney, PD competed for the majority of cortical NUC (≥70%) and PM (≥80%) sites while LOS competition predominated in medullary NUC (≥75%) and PM (≥70%). Immunodetection with an AT2antibody revealed a single ∼42-kDa band in both NUC and PM extracts, suggesting a mature molecular form of the NUC receptor. Autoradiography for receptor subtypes localized AT2in the tubulointerstitium, AT1in the medulla and vasa recta, and both AT1and AT2in glomeruli. Loading of NUC with the fluorescent nitric oxide (NO) detector DAF showed increased NO production with ANG II (1 nM), which was abolished by PD and N-nitro-l-arginine methyl ester, but not LOS. Our studies demonstrate ANG II receptor subtypes are differentially expressed in ovine kidney, while nuclear AT2receptors are functionally linked to NO production. These findings provide further evidence of a functional intracellular renin-angiotensin system within the kidney, which may represent a therapeutic target for the regulation of blood pressure.