158 research outputs found
Transient subdiffusion via disordered quantum walks
Transport phenomena play a crucial role in modern physics and applied sciences. Examples include thedissipation of energy across a large system, the distribution of quantum information in optical networks, andthe timely modeling of spreading diseases. In this work we experimentally prove the feasibility of disorderedquantum walks to realize a quantum simulator that is able to model general transient subdiffusive phenomena,exhibiting a sublinear spreading in space over time. Our experiment simulates such phenomena by means ofa finely controlled insertion of various levels of disorder during the evolution of the walker, enabled by theunique flexibility of our setup. This allows us to explore the full range of subdiffusive behaviors, ranging fromanomalous Anderson-like localization to normal diffusion for all experimentally accessible step numbers
âMULTIRACIAL AND MULTIETHNIC IDENTITY DEVELOPMENT: SHOULD THE QUESTION REALLY BE âIS THE GLASS HALF FULL OR HALF EMPTY?ââ
The purpose of this symposium is to challenge and expand the work in identity development beyond simplistic, single identity developmental frameworks by examining the inherent complexities of multiple identity development and group affiliations
Certifying the topology of quantum networks: theory and experiment
Distributed quantum information in networks is paramount for global secure
quantum communication. Moreover, it finds applications as a resource for
relevant tasks, such as clock synchronization, magnetic field sensing, and
blind quantum computation. For quantum network analysis and benchmarking of
implementations, however, it is crucial to characterize the topology of
networks in a way that reveals the nodes between which entanglement can be
reliably distributed. Here, we demonstrate an efficient scheme for this
topology certification. Our scheme allows for distinguishing, in a scalable
manner, different networks consisting of bipartite and multipartite
entanglement sources, for different levels of trust in the measurement devices
and network nodes. We experimentally demonstrate our approach by certifying the
topology of different six-qubit networks generated with polarized photons,
employing active feed-forward and time multiplexing. Our methods can be used
for general simultaneous tests of multiple hypotheses with few measurements,
being useful for other certification scenarios in quantum technologies.Comment: 18 pages, 5 figure
In vivo vasospasm induction by ultrasound application in the chicken chorioallantoic membrane model
Cerebral vasospasm is a highly investigated phenomenon in neurovascular research. Experimental vasospasm models are irreplaceable for the evaluation of new antivasospastic drugs. In this study, we assessed the reliability of in vivo vasospasm induction by ultrasound application in the chicken chorioallantoic membrane (CAM) model. After incubation of fertilized chicken eggs for four days, a fenestration was performed to enable examination of the CAM vessels. On the thirteenth day, continuous-wave ultrasound (3Â MHz, 1Â W/cm(2)) was applied on the CAM vessels for 60Â s. The ultrasound effect on the vessels was recorded by life imaging (5-MP HD-microscope camera, LeicaÂź). The induced vessel diameter changes were evaluated in a defined time interval of 20Â min using a Fiji macro. The vessel diameter before and after sonication was measured and the relative diameter reduction was determined. A first reduction of vessel diameter was observed after three minutes with an average vessel-diameter decrease to 77%. The maximum reduction in vessel diameter was reached eight minutes after sonication with an average vessel diameter decrease to 57% (mean relative diameter reduction of 43%, range 44â61%), ANOVA, pâ=â0.0002. The vasospasm persisted for all 20 recorded minutes post induction. Vasospasm can be reliably induced by short application of 3Â MHz-ultrasound to the CAM vessels. This might be a suitable in vivo model for the evaluation of drug effects on vasospasm in an experimental setting as intermediary in the transition process from in vitro to in vivo assessment using animal models
Yeast XRS2 and human NBN gene: Experimental evidence for homology using codon optimized cDNA
The genes, XRS2 in Saccharomyces cerevisiae and NBN in mammals, have little sequence identity at the amino acid level. Nevertheless, they are both found together with MRE11 and RAD50 in a highly conserved protein complex which functions in the repair of DNA double-strand breaks. Here, we have examined the evolutionary and functional relationship of these two genes by cross-complementation experiments. These experiments necessitated sequence correction for specific codon usage before they could be successfully conducted. We present evidence that despite extreme sequence divergence nibrin can, at least partially, replace Xrs2 in the cellular DNA damage response, and Xrs2 is able to promote nuclear localization of MRE11 in NBS cells. We discuss that the extreme sequence divergence reflects a unique adaptive pressure during evolution related to the specific eukaryotic role for both Xrs2 and nibrin in the subcellular localisation of the DNA repair complex. This, we suggest, is of particular relevance when cells are infected by viruses. The conflict hypothesis of co-evolution of DNA repair genes and DNA viruses may thus explain the very low sequence identity of these two homologous genes
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