3,881 research outputs found
A self-averaging spectral form factor implies unitarity breaking
The complex Fourier transform of the two-point correlator of the energy
spectrum of a quantum system is known as the spectral form factor (SFF). It
constitutes an essential diagnostic tool for phases of matter and quantum
chaos. In black hole physics, it describes the survival probability (fidelity)
of a thermofield double state under unitary time evolution. However, detailed
properties of the SFF of isolated quantum systems with generic spectra are
smeared out by large temporal fluctuations, whose minimization requires
disorder or time averages. This requirement holds for any system size, that is,
the SFF is non-self averaging. Exploiting the fidelity-based interpretation of
this quantity, we prove that using filters, disorder and time averages of the
SFF involve unitarity breaking, i.e., open quantum dynamics described by a
quantum channel that suppresses quantum noise. Specifically, averaging over
Hamiltonian ensembles, time averaging, and frequency filters can be described
by the class of mixed-unitary quantum channels in which information loss can be
recovered. Frequency filters are associated with a time-continuous master
equation generalizing energy dephasing. We also discuss the use of eigenvalue
filters. They are linked to non-Hermitian Hamiltonian evolution without quantum
jumps, whose long-time behavior is described by a Hamiltonian deformation. We
show that frequency and energy filters make the SFF self-averaging at long
times.Comment: 12 pages, 5 figure
A Post-Succession Analysis of Factors Influencing Coaching Success in NCAA Division I Men’s Basketball – Journal of Issues in Intercollegiate Athletics
Based on the reciprocal determinism component of social learning theory, a total of 736 men’s NCAA Division I basketball coaching changes between 1999 and 2014 were examined to establish which factors were related to conference success following a coaching change. Results from an exploratory latent class analysis indicated that many demographic, environmental, and experiential variables assumed to be important in hiring a new coach are insignificant. However, a program’s previous success, individual coaching ability, and previous coach vacancy circumstance are all significantly related to conference winning differential after a coaching change. Results also indicated a regression to the mean occurs after most coaching changes except for the most elite programs. Pragmatically, however, findings show relatively small increments in winning or losing following a coaching change, suggesting that the impact of a coach is often overstated. Stakeholders can use this information to evaluate coaches, programs, and hiring practices in men’s Division I basketball
A systematic framework for predictive biomarkers in immune effector cell-associated neurotoxicity syndrome
Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the management of several life-threatening malignancies, often achieving durable sustained responses. The number of patients treated with this new class of cell-based therapy, along with the number of Food and Drug Association (FDA) approved indications, are growing significantly. Unfortunately Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) can often occur after treatment with CAR-T cells, and severe ICANS can be associated with significant morbidity and mortality. Current standard treatments are mainly steroids and supportive care, highlighting the need for early identification. In the last several years, a range of predictive biomarkers have been proposed to distinguish patients at increased risk for developing ICANS. In this review, we discuss a systematic framework to organize potential predictive biomarkers that builds on our current understanding of ICANS
Direct catalytic conversion of cellulose to liquid straight-chain alkanes
High yields of liquid straight-chain alkanes were obtained directly from cellulosic feedstock in a one-pot biphasic catalytic system. The catalytic reaction proceeds at elevated temperatures under hydrogen pressure in the presence of tungstosilicic acid, dissolved in the aqueous phase, and modified Ru/C, suspended in the organic phase. Tungstosilicic acid is primarily responsible for cellulose hydrolysis and dehydration steps, while the modified Ru/C selectively hydrogenates intermediates en route to the liquid alkanes. Under optimal conditions, microcrystalline cellulose is converted to 82% n-decane-soluble products, mainly n-hexane, within a few hours, with a minimum formation of gaseous and char products. The dominant route to the liquid alkanes proceeds via 5-hydroxymethylfurfural (HMF), whereas the more common pathway via sorbitol appears to be less efficient. High liquid alkane yields were possible through (i) selective conversion of cellulose to glucose and further to HMF by gradually heating the reactor, (ii) a proper hydrothermal modification of commercial Ru/C to tune its chemoselectivity to furan hydrogenation rather than glucose hydrogenation, and (iii) the use of a biphasic reaction system with optimal partitioning of the intermediates and catalytic reactions. The catalytic system is capable of converting subsequent batches of fresh cellulose, enabling accumulation of the liquid alkanes in the organic phase during subsequent runs. Its robustness is illustrated in the conversion of the raw (soft)wood sawdust
Fibroblast growth factor homologous factor 1 interacts with NEMO to regulate NF-κB signaling in neurons.
Neuronal survival and plasticity critically depend on constitutive activity of the transcription factor nuclear factor-κB (NF-κB). We here describe a role for a small intracellular fibroblast growth factor homologue, the fibroblast growth factor homologous factor 1 (FHF1/FGF12), in the regulation of NF-κB activity in mature neurons. FHFs have previously been described to control neuronal excitability, and mutations in FHF isoforms give rise to a form of progressive spinocerebellar ataxia. Using a protein-array approach, we identified FHF1b as a novel interactor of the canonical NF-κB modulator IKKγ/NEMO. Co-immunoprecipitation, pull-down and GAL4-reporter experiments, as well as proximity ligation assays, confirmed the interaction of FHF1 and NEMO and demonstrated that a major site of interaction occurred within the axon initial segment. Fhf1 gene silencing strongly activated neuronal NF-κB activity and increased neurite lengths, branching patterns and spine counts in mature cortical neurons. The effects of FHF1 on neuronal NF-κB activity and morphology required the presence of NEMO. Our results imply that FHF1 negatively regulates the constitutive NF-κB activity in neurons
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