The Ground-state Inter-plane Superconducting Coherence Length of La1.875_{1.875}Sr0.125_{0.125}CuO4_4 Measured by a "Xiometer"

A long excitation coil piercing a superconducting (SC) ring is used to generate ever increasing persistent current in the ring, until the current destroys the order parameter. Given that the penetration depth $\lambda$ is known, this experiment measures, hypothetically, the coherence length $\xi$, hence the name "Xiometer". We examine various aspects of this theoretically driven hypothesis by testing niobium rings with different dimensions, and by comparing the results to the known values of $\xi$. We then apply the method to two La$_{1.875}$Sr$_{0.125}$CuO$_4$ rings at $T \rightarrow 0$. In one, the current flows in the CuO$_2$ planes hence it is set by $\xi_{ab}$. In the other, the current must cross planes and is determined by $\xi_{c}$. We find that $\xi_{c}=1.3 \pm 0.1$~nm, and $\xi_{ab}<2.3~$nm indicating that at low temperatures the Cooper pairs are three dimensional.Comment: 6 pages with 7 figure

Consensus in Equilibrium: Can One Against All Decide Fairly?

Is there an equilibrium for distributed consensus when all agents except one collude to steer the decision value towards their preference? If an equilibrium exists, then an n-1 size coalition cannot do better by deviating from the algorithm, even if it prefers a different decision value. We show that an equilibrium exists under this condition only if the number of agents in the network is odd and the decision is binary (among two possible input values). That is, in this framework we provide a separation between binary and multi-valued consensus. Moreover, the input and output distribution must be uniform, regardless of the communication model (synchronous or asynchronous). Furthermore, we define a new problem - Resilient Input Sharing (RIS), and use it to find an iff condition for the (n-1)-resilient equilibrium for deterministic binary consensus, essentially showing that an equilibrium for deterministic consensus is equivalent to each agent learning all the other inputs in some strong sense. Finally, we note that (n-2)-resilient equilibrium for binary consensus is possible for any n. The case of (n-2)-resilient equilibrium for multi-valued consensus is left open

Mixed superconducting state without applied magnetic field

A superconducting (SC) mixed state occurs in type-II superconductors where the upper critical field Hc2 is higher than the thermodynamic critical field Hc. When an applied field is in between these fields, the free energy depends weakly on the order parameter which therefore can be small (SC state) or zero (normal state) at different parts of the sample. In this paper we demonstrate how a normal state along a line traversing a superconductor can be turned on and off externally in zero field. The concept is based on a long, current-carrying excitation coil, piercing a ringshaped superconductor. The ring experiences zero field, but the vector potential produced by the coil generates a circular current that destroys superconductivity along a radial line starting at preexisting nucleation points in the sample. Unlike the destruction of superconductivity with magnetic field, the vector potential method is reversible and reproducible; full superconductivity is recovered upon removing the current from the coil, and different cooldowns yield the same normal lines. We suggest potential applications of this magnetic-field-free mixed state.Comment: 5 pages, 7 figure

The two critical temperatures conundrum in La1.83_{1.83}Sr0.17_{0.17}CuO4_4

The in-plane and out-of-plane superconducting stiffness appear to vanish at different transition temperatures, which contradicts thermodynamical expectation. In addition, we observe a surprisingly strong dependence of the out-of-plane stiffness transition on sample width. With evidence from Monte Carlo simulations, this effect is explained by a crossover from three dimensions into quasi one dimensional behavior of the finite sample. Due to an essential singularity at the thermodynamic transition temperature $T_c$, the out-of-plane stiffness appears to vanish below $T_c$ by an amount which is proportional to the inverse width. A fit of our prediction to the data is used to determine the value of the anisotropy parameter. Analogy to studies of helium superfluids in nanopores is made

SUGGESTING TITLES FOR AUDIO RECORDINGS

Techniques of this disclosure may enable a computing device to suggest one or more titles based on the content of audio being recorded or audio that was previously recorded, and other data such as time and location. Rather than applying a general default title or audio file name, the computing device may request authorization from a user to analyze the contents of a recorded audio file and, after receiving explicit authorization from the user, analyze the audio, including speech, and automatically suggest titles that are indicative of the content of the audio and/or other data. The computing device may convert speech included in the audio into text and extract a plurality of terms from the text based on various factors, such as word classes (e.g., convert audio that includes “this meatball recipe adds parmesan cheese” into text and extract a plurality of nouns such as “meatball,” “recipe,” “parmesan,” and “cheese” from the text). Based on various factors, such as term frequency in the text and the relative uniqueness of the terms in the spoken language, the computing device may identify a plurality of words from the plurality of terms to represent the overall content of the audio (e.g., identify “meatball” and “recipe” from “meatball,” “recipe,” “parmesan,” and “cheese” based on term frequency in the text). The computing device may also classify non-speech audio (e.g. applause, dog barking, music) and use the classification, including metadata associated with the classified audio object, such as song titles, to identify a plurality of words to represent the overall content of the audio. The speech terms, non-speech audio classification, classified audio object metadata, and other data may be combined to identify a plurality of words to represent the overall content of the audio. The computing device may display the identified words as suggested words to be included in the title of the audio file. The user may select one or more of the identified words as the title or combine one or more of the identified words with one or more other words entered by the user. The computing device may use the selected and/or entered words as the title for the audio and/or for the name of the audio file

Defining the Transcriptional Landscape during Cytomegalovirus Latency with Single-Cell RNA Sequencing

Primary infection with human cytomegalovirus (HCMV) results in a lifelong infection due to its ability to establish latent infection, with one characterized viral reservoir being hematopoietic cells. Although reactivation from latency causes serious disease in immunocompromised individuals, our molecular understanding of latency is limited. Here, we delineate viral gene expression during natural HCMV persistent infection by analyzing the massive RNA-seq atlas generated by the Genotype-Tissue Expression (GTEx) project. This systematic analysis reveals that HCMV persistence in-vivo is prevalent in diverse tissues. Unexpectedly, we find only viral transcripts that resemble gene expression during various stages of lytic infection with no evidence of any highly restricted latency-associated viral gene expression program. To further define the transcriptional landscape during HCMV latent infection, we also used single cell RNA-seq and a tractable experimental latency model. In contrast to some current views on latency, we also find no evidence for any highly restricted latency-associated viral gene expression program. Instead, we reveal that latency-associated gene expression largely mirrors a late lytic viral program albeit at much lower levels of expression. Overall, our work has the potential to revolutionize our understanding of HCMV persistence and suggests that latency is governed mainly by quantitative changes, with a limited number of qualitative changes, in viral gene expression.This research was supported by the EU-FP7-PEOPLE career integration grant, the Israeli Science Foundation (1073/14; N.S.-G.), Infect-ERA (TANKACY; N.S.-G.), the European Research Council starting grant (StG-2014-638142; N.S.-G.), the British Medical Research Programme (grant G0701279; J.S.), a Wellcome Research Studentship Grant (B.K.), and the Cambridge NIHR BRC Cell Phenotyping Hub. N.S.-G. is incumbent of the Skirball career development chair in new scientist