22,857 research outputs found
Komar Integrals in Higher (and Lower) Derivative Gravity
The Komar integral relation of Einstein gravity is generalized to Lovelock
theories of gravity. This includes, in particular, a new boundary integral for
the Komar mass in Einstein gravity with a nonzero cosmological constant, which
has a finite result for asymptotically AdS black holes, without the need for an
infinite background subtraction. Explicit computations of the Komar mass are
given for black holes in pure Lovelock gravities of all orders and in general
Gauss-Bonnet theories.Comment: 16 pages; v2 - references and comment on relation to Noether charge
method adde
SpZ12-1, a negative regulator required for spatial control of the territory-specific CyIIIa gene in the sea urchin embryo
The CyIIIa cytoskeletal actin gene of the sea urchin Strongylocentrotus purpuratus is activated in late cleavage and expressed exclusively in the aboral ectoderm territory of the embryo. Previous gene transfer studies defined a 2.3 kb cis-regulatory region that is necessary and sufficient for correct temporal and spatial expression of a CyIIIa. CAT fusion gene. In this paper, a negative regulatory element within this region was identified that is required for repression of the CyIIIa gene in skeletogenic mesenchyme cells. The repression mediated by this regulatory element takes place after initial territorial specification. A cDNA clone encoding a DNA-binding protein with twelve Zn fingers (SpZ12-1) was isolated by probing an expression library with this cis-element. Deletion analysis of the SpZ12-1 protein confirmed that a DNA-binding domain is located within the Zn finger region. SpZ12-1 is the only DNA-binding protein in embryo nuclear extract that interacts with the specific cis-target sites required for repression of CyIIIa.CAT in skeletogenic mesenchyme and is likely to be the trans factor that mediates this repression
Coping with newcomer āhangoverā: how socialization tactics affect declining job satisfaction during early employment
New entrants to a job often experience a āhangover effect,ā whereby their job satisfaction declines as they become familiar with the job. Socialization scholars thus have sought to identify ways to forestall or ameliorate such declines. Recently, Boswell, Shipp, Payne, and Culbertson (2009) found that the extent of socialization can exacerbate the hangover effect. Following up this provocative finding, this study investigated whether socialization tactics worsen or dampen the hangover effect and by so doing, affect newcomer attrition. We monitored how newcomers' job satisfaction changed over time by surveying them on four occasions during the first six months of employment. We observed that socialization tactics (especially context and social tactics) increase the rate of declining job satisfaction during early employment. Yet all three tactics decrease this descent rate when enacted at high levels. Moreover, the present research established that declining job satisfaction translates into a trajectory of increasing turnover intentions and thus higher quits. Further, we found that extremely high social tactics can actually suppress the hangover effect and thereby reduce newcomer attrition. Our dynamic research offered a more nuanced understanding of how socialization tactics influence the hangover effect and newcomer attrition
The Bloch-Okounkov correlation functions, a classical half-integral case
Bloch and Okounkov's correlation function on the infinite wedge space has
connections to Gromov-Witten theory, Hilbert schemes, symmetric groups, and
certain character functions of \hgl_\infty-modules of level one. Recent works
have calculated these character functions for higher levels for \hgl_\infty
and its Lie subalgebras of classical type. Here we obtain these functions for
the subalgebra of type of half-integral levels and as a byproduct, obtain
-dimension formulas for integral modules of type at half-integral level.Comment: v2: minor changes to the introduction; accepted for publication in
Letters in Mathematical Physic
Synchronization of coupled neural oscillators with heterogeneous delays
We investigate the effects of heterogeneous delays in the coupling of two
excitable neural systems. Depending upon the coupling strengths and the time
delays in the mutual and self-coupling, the compound system exhibits different
types of synchronized oscillations of variable period. We analyze this
synchronization based on the interplay of the different time delays and support
the numerical results by analytical findings. In addition, we elaborate on
bursting-like dynamics with two competing timescales on the basis of the
autocorrelation function.Comment: 18 pages, 14 figure
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