Codimension One Branes

We study codimension one branes, i.e. p-branes in (p+2)-dimensions, in the superembedding approach for the cases where the worldvolume superspace is embedded in a minimal target superspace with half supersymmetry breaking. This singles out the cases p=1,2,3,5,9. For p=3,5,9 the superembedding geometry naturally involves a fundamental super 2-form potential on the worldvolume whose generalised field strength obeys a constraint deducible from considering an open supermembrane ending on the p-brane. This constraint, together with the embedding constraint, puts the system on-shell for p=5 but overconstrains the 9-brane in D=11 such that the Goldstone superfield is frozen. For p=3 these two constraints give rise to an off-shell linear multiplet on the worldvolume. An alternative formulation of this case is given in which the linear multiplet is dualised to an off-shell scalar multiplet. Actions are constructed for both cases and are shown to give equivalent equations of motion. After gauge fixing a local Sp(1) symmetry associated with shifts in the Sp(1)_R Goldstone modes, we find that the auxiliary fields in the scalar multiplet parametrise a two-sphere. For completeness we also discuss briefly the cases p=1,2 where the equations of motion (for off-shell multiplets) are obtained from an action principle.Comment: 38 pages, latex, cover page correcte

Effects of antimitotic agents on haploid plant production from unpollinated ovules of sugar beet (beta vulgaris l.)

The effects of antimicrotubule agents on haploid embryo formation from unpollinated ovules of sugar beet (Beta vulgaris L.) were investigated. The antimitotic agent colchicine (at 100 and 150 mg/l) and trifluralin (at 5.0 mg/l) increased the frequency of haploid embryo formation whereas pronamide (at 76.9 and 128.2 mg/l) and trifluralin (at 3.4 mg/l) decreased. Ovules that were non-treated with antimicrotuble agents (i.e., ovules of the control treatment) produced higher percentages of haploid embryos (4.25 %) when compared to the pronamide and trifluralin at 3.4 mg/l concentration. Toxic effects of these agents on embryo formation from ovules were evident. A significant genotypic variation among the lines used was observed. The line M4 produced the highest yield with a mean of 14.71% haploid embryo production while the line M2 producing no embryos at all

Origins of Chevron Rollovers in Non-Two-State Protein Folding Kinetics

Chevron rollovers of some proteins imply that their logarithmic folding rates are nonlinear in native stability. This is predicted by lattice and continuum G\=o models to arise from diminished accessibilities of the ground state from transiently populated compact conformations under strongly native conditions. Despite these models' native-centric interactions, the slowdown is due partly to kinetic trapping caused by some of the folding intermediates' nonnative topologies. Notably, simple two-state folding kinetics of small single-domain proteins are not reproduced by common G\=o-like schemes.Comment: 10 pages, 4 Postscript figures (will appear on PRL

The value of laparoscopic classifications in decision on definitive surgery in patients with nonpalpable testes: our experience and review of the literature

Background/purpose The aim of the study was to present our clinical experience with the laparoscopic approach in patients with nonpalpable testes (NPTs) and review the literature on laparoscopic classifications.Materials and methods Between May 2010 and August 2012, 30 boys with NPT (mean age 3.9 years) underwent laparoscopy as a part of diagnosis and treatment in our clinic. The laparoscopic findings were classified into four types according to Castilho. The patients were managed according to the presence or position of the testes and testicular vessels.Results Six patients were excluded from the study. Twenty-six testicular units (19 left, three right, and four bilateral units) in 24 patients were managed laparoscopically. Laparoscopy was terminated in eight patients in whom blind-ending cord structures were detected intra-abdominally. An inguinal canal exploration was performed in 10 cases in whom cord structures were seen entering the internal inguinal ring. No viable testis was found, and testicular remnants were excised for histopathologic examination. Four canalicular testes (peeping) were treated with open orchiopexy. Laparoscopy-assisted orchiopexy without vascular ligation was performed in two testes. Fowler-Stephens orchiopexy in single stage was performed in one testicular unit and in two stages in another unit. All patients were discharged on the same day. The testes were normal in size and found in the scrotum after a mean follow-up period of 14 months.Conclusion The laparoscopic findings in NPT had an important influence on treatment decisions. To be able to interpret the definitive surgery relative to the laparoscopic classification, collaborative studies are required. Keywords: laparoscopy, nonpalpable testis, nubbin, orchiopexy, vas deferen

Dynamical decompactification from brane gases in eleven-dimensional supergravity

Brane gas cosmology provides a dynamical decompactification mechanism that could account for the number of spacetime dimensions we observe today. In this work we discuss this scenario taking into account the full bosonic sector of eleven-dimensional supergravity. We find new cosmological solutions that can dynamically explain the existence of three large spatial dimensions characterised by an universal asymptotic scaling behaviour and a large number of initially unwrapped dimensions. This type of solutions enlarge the possible initial conditions of the Universe in the Hagedorn phase and consequently can potentially increase the probability of dynamical decompactification from anisotropically wrapped backgrounds.Comment: 8 figures, JHEP3 styl

Hydrodynamic Equation for the Breakdown of the Quantum Hall Effect in a Uniform Current

The hydrodynamic equation for the spatial and temporal evolution of the electron temperature T_e in the breakdown of the quantum Hall effect at even-integer filling factors in a uniform current density j is derived from the Boltzmann-type equation, which takes into account electron-electron and electron-phonon scatterings. The derived equation has a drift term, which is proportional to j and to the first spatial derivative of T_e. Applied to the spatial evolution of T_e in a sample with an abrupt change of the width along the current direction, the equation gives a distinct dependence on the current direction as well as a critical relaxation, in agreement with the recent experiments.Comment: 4 pages, 1 Postscript figure, corrected equations, to be published in J. Phys. Soc. Jpn. 70 (2001) No.

Spectrum of D=6, N=4b Supergravity on AdS_3 x S^3

The complete spectrum of D=6, N=4b supergravity with n tensor multiplets compactified on AdS_3 x S^3 is determined. The D=6 theory obtained from the K_3 compactification of Type IIB string requires that n=21, but we let n be arbitrary. The superalgebra that underlies the symmetry of the resulting supergravity theory in AdS_3 coupled to matter is SU(1,1|2)_L x SU(1,1|2)_R. The theory also has an unbroken global SO(4)_R x SO(n) symmetry inherited from D=6. The spectrum of states arranges itself into a tower of spin-2 supermultiplets, a tower of spin-1, SO(n) singlet supermultiplets, a tower of spin-1 supermultiplets in the vector representation of SO(n) and a special spin-1/2 supermultiplet also in the vector representation of SO(n). The SU(2)_L x SU(2)_R Yang-Mills states reside in the second level of the spin-2 tower and the lowest level of the spin-1, SO(n) singlet tower and the associated field theory exhibits interesting properties.Comment: 37 pages, latex, 5 tables and 3 figures, typos corrected, a reference adde

Analisis Status Nitrogen Tanah dalam Kaitannya dengan Serapan N oleh Tanaman Padi Sawah di Desa Waimital, Kecamatan Kairatu, Kabupaten Seram Bagian Barat

Nitrogen is a major nutrient for plant growth. Nitrogen function to increase vegetative growth, increase the number of tillers and increase the number of grains/clusters and increase the size of rice grain. The purpose of research was to analyze the availability of N in the soil and plant N content, and calculating fertilizer needs to increase rice productivity. Research was conducted using survey methods with an area sampling approach, conducted in October 2012 - January 2013. The research area was 590.6 ha. The soil total N ranged from very low (KP3 and 5 at 0.06% and 0.09% respectively), until low (KP 1, 2, 4, 6 and 7 at 0.14%, 0.15%, 0.13% 0.17% and 0.14% respectively. Meanwhile, the plant N sampled from the start of grain filling until harvest were low, ranged from 1% - 1.31%. The doses of fertilizer needed to sustain 5 ton ha-1 rice for the next planting season by adding Urea were as much as KP 1 (224.3 kg ha-1), KP 2 (224.25 kg ha-1), KP 3 (224.7 kg ha-1), KP 4 (224.35 kg ha-1), KP 5 (224.55 kg ha-1), KP 6 (224.15 kg ha-1) and KP 7 (224.3 kg ha-1)

Hydrodynamic Equations in Quantum Hall Systems at Large Currents

Hydrodynamic equations (HDEQs) are derived which describe spatio-temporal evolutions of the electron temperature and the chemical potential of two-dimensional systems in strong magnetic fields in states with large diagonal resistivity appearing at the breakdown of the quantum Hall effect. The derivation is based on microscopic electronic processes consisting of drift motions in a slowly-fluctuating potential and scattering processes due to electron-electron and electron-phonon interactions. In contrast with the usual HDEQs, one of the derived HDEQs has a term with an energy flux perpendicular to the electric field due to the drift motions in the magnetic field. As an illustration, the current distribution is calculated using the derived HDEQs.Comment: 10 pages, 2 Postscript figures, to be published in J. Phys. Soc. Jpn. 71 (2002) No.

Interaction Rates in String Gas Cosmology

We study string interaction rates in the Brandenberger-Vafa scenario, the very early universe cosmology of a gas of strings. This cosmology starts with the assumption that all spatial dimensions are compact and initially have string scale radii; some dimensions grow due to some thermal or quantum fluctuation which acts as an initial expansion velocity. Based on simple arguments from the low energy equations of motion and string thermodynamics, we demonstrate that the interaction rates of strings are negligible, so the common assumption of thermal equilibrium cannot apply. We also present a new analysis of the cosmological evolution of strings on compact manifolds of large radius. Then we discuss modifications that should be considered to the usual Brandenberger-Vafa scenario. To confirm our simple arguments, we give a numerical calculation of the annihilation rate of winding strings. In calculating the rate, we also show that the quantum mechanics of strings in small spaces is important.Comment: 28pp, 3 figures, RevTeX