1,117 research outputs found
Deregulation and environmental differentiation in the electric utility industry.
This paper analyzes how economic deregulation impacts firm strategies and environmental quality in the electric utility industry. We find evidence that the deregulation introduced to this historically staid industry has stimulated environmental differentiation. Differentiation is most likely to appear where its point of uniqueness is valued by customers, and we confirm this relationship in our sample. Specifically, utilities that served customers who exhibited higher levels of environmental sensitivity generated more green power. The tendency for firms to differentiate in this way is lessened if they are relatively more dependent on coal-fired generation or relatively more efficient. Thus, there is evidence that firms sort themselves into either differentiation or low-cost strategies as the competitive realities of a deregulated world unfold. Deregulation and the ensuing environmental differentiation illustrate how utilities exploited formerly unmet customer demand for green power. The result has been greater levels of renewable generation and, hence, a cleaner environment.Deregulation; Environmental differentiation; Electric utility; Renewable energy; Productive efficiency;
One-dimensional Diffusion-limited Relaxation of Photoexcitations in Suspensions of Single-walled Carbon Nanotubes
We report pump-probe transient absorption spectroscopy on carbon nanotubes with a high initial excitation density. We find that the recovery of the ground state optical absorption is well described by a 1/√t relaxation, indicating that the long time population relaxation is controlled by one-dimensional diffusion limited two body recombination
Probabilistic representation for solutions of an irregular porous media type equation: the degenerate case
We consider a possibly degenerate porous media type equation over all of
with , with monotone discontinuous coefficients with linear
growth and prove a probabilistic representation of its solution in terms of an
associated microscopic diffusion. This equation is motivated by some singular
behaviour arising in complex self-organized critical systems. The main idea
consists in approximating the equation by equations with monotone
non-degenerate coefficients and deriving some new analytical properties of the
solution
D-instanton partition functions
Duality arguments are used to determine D-instanton contributions to certain
effective interaction terms of type II supergravity theories in various
dimensions. This leads to exact expressions for the partition functions of the
finite N D-instanton matrix model in d=4 and 6 dimensions that generalize our
previous expression for the case d=10. These results are consistent with the
fact that the Witten index of the T-dual D-particle process should only be
non-vanishing for d=10.Comment: 20 pages, harvmac, typos corrected, reference adde
Leptin and Associated Mediators of Immunometabolic Signaling: Novel Molecular Outcome Measures for Neurostimulation to Treat Chronic Pain
Chronic pain is a devastating condition affecting the physical, psychological, and socioeconomic status of the patient. Inflammation and immunometabolism play roles in the pathophysiology of chronic pain disorders. Electrical neuromodulation approaches have shown a meaningful success in otherwise drug-resistant chronic pain conditions, including failed back surgery, neuropathic pain, and migraine. A literature review (PubMed, MEDLINE/OVID, SCOPUS, and manual searches of the bibliographies of known primary and review articles) was performed using the following search terms: chronic pain disorders, systemic inflammation, immunometabolism, prediction, biomarkers, metabolic disorders, and neuromodulation for chronic pain. Experimental studies indicate a relationship between the development and maintenance of chronic pain conditions and a deteriorated immunometabolic state mediated by circulating cytokines, chemokines, and cellular components. A few uncontrolled in-human studies found increased levels of pro-inflammatory cytokines known to drive metabolic disorders in chronic pain patients undergoing neurostimulation therapies. In this narrative review, we summarize the current knowledge and possible relationships of available neurostimulation therapies for chronic pain with mediators of central and peripheral neuroinflammation and immunometabolism on a molecular level. However, to address the needs for predictive factors and biomarkers, large-scale databank driven clinical trials are needed to determine the clinical value of molecular profiling
Giant Gravitons - with Strings Attached (III)
We develop techniques to compute the one-loop anomalous dimensions of
operators in the super Yang-Mills theory that are dual to open
strings ending on boundstates of sphere giant gravitons. Our results, which are
applicable to excitations involving an arbitrary number of open strings,
generalize the single string results of hep-th/0701067. The open strings we
consider carry angular momentum on an S embedded in the S of the
AdSS background. The problem of computing the one loop anomalous
dimensions is replaced with the problem of diagonalizing an interacting Cuntz
oscillator Hamiltonian. Our Cuntz oscillator dynamics illustrates how the
Chan-Paton factors for open strings propagating on multiple branes can arise
dynamically.Comment: 66 pages; v2: improved presentatio
Equilibrium Two-Dimensional Dilatonic Spacetimes
We study two-dimensional dilaton gravity coupled to massless scalar fields
for static solutions. In addition to the well known black hole, we find another
class of solutions that may be understood as that of the black hole in
equilibrium with a radiation bath. We claim that there is a solution that is
qualitatively unchanged after including Hawking radiation and back-reaction and
is furthermore geodesically complete. We compute the thermodynamics of these
spacetimes and their mass. We end with a brief discussion of the linear
response about these solutions, its significance to stability and noise and a
speculation regarding the endpoint of Hawking evaporation in four dimensions.
(plain TeX; one figure, available upon request.)Comment: 22 pages, M.I.T. preprint CTP#217
Measurement of eta_c(1S), eta_c(2S) and non-resonant eta' pi+ pi- production via two-photon collisions
We report the measurement of gamma gamma to eta_c(1S), eta_c(2S) to eta' pi+
pi- with eta' decays to gamma rho and eta pi+ pi- using 941 fb^{-1} of data
collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.
The eta_c(1S) mass and width are measured to be M = [2984.6\pm0.7 (stat.)\pm2.2
(syst.)] MeV/c^{2} and \Gamma = [30.8^{+2.3}_{-2.2}~(stat.) \pm 2.5~(syst.)]
MeV, respectively. First observation of eta_c(2S) to eta' pi+ pi- with a
significance of 5.5sigma including systematic error is obtained, and the
eta_c(2S) mass is measured to be M = [3635.1\pm3.7~(stat.)\pm2.9~(syst.)]
MeV/c^{2}. The products of the two-photon decay width and branching fraction
(B) of decays to eta'pi+ pi- are determined to be \Gamma_{gamma gamma}B =
[65.4\pm2.6~(stat.)\pm6.9~(syst.)] eV for eta_c(1S) and
[5.6^{+1.2}_{-1.1}~(stat.)\pm1.1~(syst.)] eV for eta_c(2S). A new decay mode
for the eta_c(1S) to eta'f_0(2080) with f_0(2080) to pi+ pi- is observed with a
statistical significance of 20sigma. The f_0(2080) mass and width are
determined to be M = [2083^{+63}_{-66}~(stat.)\pm 32~(syst.)] MeV/c^{2} and
\Gamma = [178^{+60}_{-178}~(stat.) \pm 55~(syst.)] MeV. The cross sections for
gamma gamma to eta' pi+ pi- and eta'f_{2}(1270) are measured for the first
time.Comment: 19 pages, 14 figure
Measurement of Branching Fractions of Hadronic Decays of the Baryon
Using a data sample of 980 of annihilation data
taken with the Belle detector operating at the KEKB asymmetric-energy
collider, we report the results of a study of the decays of the
charmed baryon into hadronic final states. We report the most precise
measurements to date of the relative branching fractions of the
into , , , and
, as well as the first measurements of the branching fractions
of the into , , and , all with respect to the decay. In
addition, we investigate the resonant substructure of these modes. Finally, we
present a limit on the branching fraction for the decay
Defensome against Toxic Diatom Aldehydes in the Sea Urchin Paracentrotus lividus
Many diatom species produce polyunsaturated aldehydes, such as decadienal, which compromise embryonic and larval development in benthic organisms. Here newly fertilized Paracentrotus lividus sea urchins were exposed to low concentration of decadienal and the expression levels of sixteen genes, implicated in a broad range of functional responses, were followed by Real Time qPCR in order to identify potential decadienal targets. We show that at low decadienal concentrations the sea urchin Paracentrotus lividus places in motion different classes of genes to defend itself against this toxic aldehyde, activating hsp60 and two proteases, hat and BP10, at the blastula stage and hsp56 and several other genes (14-3-3ε, p38 MAPK, MTase, and GS) at the prism stage. At this latter stage all genes involved in skeletogenesis (Nec, uni, SM50 and SM30) were also down-expressed, following developmental abnormalities that mainly affected skeleton morphogenesis. Moreover, sea urchin embryos treated with increasing concentrations of decadienal revealed a dose-dependent response of activated target genes. Finally, we suggest that this orchestrated defense system against decadienal represents part of the chemical defensome of P. lividus affording protection from environmental toxicants
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