1,559 research outputs found
Artisans, Athletes, Entrepreneurs, and Other Skilled Exemplars of the Way
We introduce management and spirituality scholars to the “knack” passages from the c. 4th century B.C.E. text, the Zhuangzi. The knack passages are parables about low status figures, such as wheelwrights, furniture makers and cooks, whose actions offer insights into the spirituality of ordinary work and, we argue, of entrepreneurship. Such non-corporate settings are lesser-studied domains for spirituality. Ancient Chinese writings have been noticed by spirituality and management writers but we call for deeper scholarly textual attention. We seek also to model more attention to the renaissance in scholarship on classical China. More ambitiously, we hope to show that these passages are not only germane but worthy of careful consideration. Our efforts reflect the influence of Slingerland\u27s (2003) study of “effortless action” as a central soteriological goal in ancient China
Cold Induction of EARLI1, a Putative Arabidopsis Lipid Transfer Protein, Is Light and Calcium Dependent
As sessile organisms, plants must adapt to their environment. One approach toward understanding this adaptation is to investigate environmental regulation of gene expression. Our focus is on the environmental regulation of EARLI1, which is activated by cold and long-day photoperiods. Cold activation of EARLI1 in short-day photoperiods is slow, requiring several hours at 4ºC to detect an increase in mRNA abundance. EARLI1 is not efficiently cold-activated in etiolated seedlings, suggesting that photomorphogenesis is necessary for its cold activation. Cold activation of EARLI1 is inhibited in the presence of the calcium channel blocker lanthanum chloride or the calcium chelator EGTA. Addition of the calcium ionophore Bay K8644 results in cold-independent activation of EARLI1. These data suggest that EARLI1 is not an immediate target of the cold response, and that calcium flux affects its expression. EARLI1 is a putative secreted protein and has motifs found in lipid transfer proteins. Over-expression of EARLI1 in transgenic plants results in reduced electrolyte leakage during freezing damage, suggesting that EARLI1 may affect membrane or cell wall stability in response to low temperature stress
Density Waves in a Transverse Electric Field
In a quasi-one-dimensional conductor with an open Fermi surface, a Charge or
a Spin Density Wave phase can be destroyed by an electric field perpendicular
to the direction of high conductivity. This mechanism, due to the breakdown of
electron-hole symmetry, is very similar to the orbital destruction of
superconductivity by a magnetic field, due to time-reversal symmetry.Comment: 3 pages, Latex, 2 figures, to appear in Phys. Rev. B Rapid Com
Calorons, Nahm's equations on S^1 and bundles over P^1xP^1
The moduli space of solutions to Nahm's equations of rank (k,k+j) on the
circle, and hence, of SU(2) calorons of charge (k,j), is shown to be equivalent
to the moduli of holomorphic rank 2 bundles on P^1xP^1 trivialized at infinity
with c_2=k and equipped with a flag of degree j along P^1x{0}. An explicit
matrix description of these spaces is given by a monad constructio
Possible Z2 phase and spin-charge separation in electron doped cuprate superconductors
The SU(2) slave-boson mean-field theory for the tt'J model is analyzed. The
role of next-nearest-neighbor hopping t' on the phase-diagram is studied. We
find a pseudogap phase in hole-doped materials (where t'<0). The pseudo-gap
phase is a U(1) spin liquid (the staggered-flux phase) with a U(1) gauge
interaction and no fractionalization. This agrees with experiments on hole
doped samples. The same calculation also indicates that a positive t' favors a
Z2 state with true spin-charge separation. The Z2 state that exists when t' >
0.5J can be a candidate for the pseudo-gap phase of electron-doped cuprates (if
such a phase exists). The experimental situation in electron-doped materials is
also addressed.Comment: 6 pages, 2 figures, RevTeX4. Homepage http://dao.mit.edu/~wen
Autogenic evolution of valley-confined deltas during sea-level rise: Insights from numerical and physical modelling
Nearshore incised valleys are important conduits for the transport of sediment, nutrients, pollutants and organic carbon from the continents to the sea. Therefore, it is essential to understand the autogenic evolution of deltas confined within incised valleys and how such evolution is affected by relative sea-level rise. To date, limited research has focused on how deltas constrained by incised valleys or other forms of antecedent topography respond to rising sea level. An existing theory of autostratigraphy envisages scenarios in which two-dimensional or unconfined three-dimensional fan deltas can experience three evolutionary stages under constant rates of relative sea-level rise and sediment supply: progradation, autoretreat and post-autobreak transgression. In this work, an integrated study of geometric numerical models and physical experiments is undertaken to investigate autostratigraphic delta evolution for a variety of incised-valley geometries, under conditions of constant rates of relative sea-level rise and sediment supply. Results indicate that interplays of antecedent topography (valley geometries) and sediment mass balance expressed in resultant deltaic geometries can result in autogenic changes in shoreline dynamics and river avulsion frequency on deltas. The following primary findings arise. (i) Compared to valleys with rectangular and trapezoidal cross-sectional profiles, valleys with triangular cross-sections tend to contain deltas that experience faster rates of progradation, autoretreat and post-autobreak transgression under rising sea level, and exhibit a more prominent convex-seaward shoreline trajectory. (ii) The shoreline trajectory is also related to delta topset geometry, becoming more convex-seaward under decreasing topset slopes. (iii) River avulsion frequency on deltas with rising sea level varies markedly across valleys with different geometries, even under the same rate of relative sea-level rise; this is attributed to the difference in temporal evolution of shoreline migration for different valley geometries and the resultant difference in the delta topset aggradation. This study highlights complexities in responses of sedimentary systems under the confinement of different topographic configurations that have hitherto largely been overlooked in sequence-stratigraphic models. The findings provide insight into future shoreline behaviour and river avulsion hazard on confined deltas, and for decoding the stratigraphic record
Out-of-equilibrium quantum fields with conserved charge
We study the out-of-equilibrium evolution of an O(2)-invariant scalar field
in which a conserved charge is stored. We apply a loop expansion of the
2-particle irreducible effective action to 3-loop order. Equations of motion
are derived which conserve both total charge and total energy yet allow for the
effects of scattering whereby charge and energy can transfer between modes.
Working in (1+1)-dimensions we solve the equations of motion numerically for a
system knocked out of equilibrium by a sudden temperature quench. We examine
the initial stages of the charge and energy redistribution. This provides a
basis from which we can understand the formation of Bose-Einstein condensates
from first principles.Comment: 11 pages, 5 figures, replacement with improved presentatio
Weak localization of disordered quasiparticles in the mixed superconducting state
Starting from a random matrix model, we construct the low-energy effective
field theory for the noninteracting gas of quasiparticles of a disordered
superconductor in the mixed state. The theory is a nonlinear sigma model, with
the order parameter field being a supermatrix whose form is determined solely
on symmetry grounds. The weak localization correction to the field-axis thermal
conductivity is computed for a dilute array of s-wave vortices near the lower
critical field H_c1. We propose that weak localization effects, cut off at low
temperatures by the Zeeman splitting, are responsible for the field dependence
of the thermal conductivity seen in recent high-T_c experiments by Aubin et al.Comment: RevTex, 8 pages, 1 eps figure, typos correcte
Boundary Action of N=2 Super-Liouville Theory
We derive a boundary action of N=2 super-Liouville theory which preserves
both N=2 supersymmetry and conformal symmetry by imposing explicitly and . The resulting boundary action shows a new duality
symmetry.Comment: 15 pages; One reference is adde
Hot Spots and Transition from d-Wave to Another Pairing Symmetry in the Electron-Doped Cuprate Superconductors
We present a simple theoretical explanation for a transition from d-wave to
another superconducting pairing observed in the electron-doped cuprates. The
d_{x^2-y^2} pairing potential Delta, which has the maximal magnitude and
opposite signs at the hot spots on the Fermi surface, becomes suppressed with
the increase of electron doping, because the hot spots approach the Brillouin
zone diagonals, where Delta vanishes. Then, the d_{x^2-y^2} pairing is replaced
by either singlet s-wave or triplet p-wave pairing. We argue in favor of the
latter and discuss experiments to uncover it.Comment: 6 pages, 4 figures, RevTeX 4. V.2: Extra figure and many references
added. V.3: Minor update of references for the proof
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