Coulomb Blockade and Coherent Single-Cooper-Pair Tunneling in Single Josephson Junctions

We have measured the current-voltage characteristics of small-capacitance single Josephson junctions at low temperatures (T < 0.04 K), where the strength of the coupling between the single junction and the electromagnetic environment was controlled with one-dimensional arrays of dc SQUIDs. We have clearly observed Coulomb blockade of Cooper-pair tunneling and even a region of negative differential resistance, when the zero-bias resistance of the SQUID arrays is much higher than the quantum resistance h/e^2 = 26 kohm. The negative differential resistance is evidence of coherent single-Cooper-pair tunneling in the single Josephson junction.Comment: RevTeX, 4 pages with 6 embedded figure

Quantum Effects in Small-Capacitance Single Josephson Junctions

We have measured the current-voltage (I-V) characteristics of small-capacitance single Josephson junctions at low temperatures (T=0.02-0.6 K), where the strength of the coupling between the single junction and the electromagnetic environment was controlled with one-dimensional arrays of dc SQUIDs. The single-junction I-V curve is sensitive to the impedance of the environment, which can be tuned IN SITU. We have observed Coulomb blockade of Cooper-pair tunneling and even a region of negative differential resistance, when the zero-bias resistance R_0' of the SQUID arrays is much higher than the quantum resistance R_K = h/e^2 = 26 kohm. The negative differential resistance is evidence of coherent single-Cooper-pair tunneling within the theory of current-biased single Josephson junctions. Based on the theory, we have calculated the I-V curves numerically in order to compare with the experimental ones at R_0' >> R_K. The numerical calculation agrees with the experiments qualitatively. We also discuss the R_0' dependence of the single-Josephson-junction I-V curve in terms of the superconductor-insulator transition driven by changing the coupling to the environment.Comment: 11 pages with 14 embedded figures, RevTeX4, final versio

Single-cell analysis of human glioma and immune cells identifies S100A4 as an immunotherapy target.

A major rate-limiting step in developing more effective immunotherapies for GBM is our inadequate understanding of the cellular complexity and the molecular heterogeneity of immune infiltrates in gliomas. Here, we report an integrated analysis of 201,986 human glioma, immune, and other stromal cells at the single cell level. In doing so, we discover extensive spatial and molecular heterogeneity in immune infiltrates. We identify molecular signatures for nine distinct myeloid cell subtypes, of which five are independent prognostic indicators of glioma patient survival. Furthermore, we identify S100A4 as a regulator of immune suppressive T and myeloid cells in GBM and demonstrate that deleting S100a4 in non-cancer cells is sufficient to reprogram the immune landscape and significantly improve survival. This study provides insights into spatial, molecular, and functional heterogeneity of glioma and glioma-associated immune cells and demonstrates the utility of this dataset for discovering therapeutic targets for this poorly immunogenic cancer

Pointing to visible and invisible targets

We investigated how the visibility of targets influenced the type of point used to provide directions. In Study 1 we asked 605 passersby in three localities for directions to well-known local landmarks. When that landmark was in plain view behind the requester, most respondents pointed with their index fingers, and few respondents pointed more than once. In contrast, when the landmark was not in view, respondents pointed initially with their index fingers, but often elaborated with a whole-hand point. In Study 2, we covertly filmed the responses from 157 passersby we approached for directions, capturing both verbal and gestural responses. As in Study 1, few respondents produced more than one gesture when the target was in plain view and initial points were most likely to be index finger points. Thus, in a Western geographical context in which pointing with the index finger is the dominant form of pointing, a slight change in circumstances elicited a preference for pointing with the whole hand when it was the second or third manual gesture in a sequence

CHARACTERIZING ELYSIUM'S MAGMATIC EVOLUTION AND CHEMISTRY INITIAL STUDY

International audienceIntroduction: The Elysium volcanic province (EVP) is a location of great geologic interest on Mars. EVP is notable not only for the presence of three shield volcanoes, Elysium, Alber, and Hecates, but also for some of the most recent eruptions on the planet, with some interpretations suggesting activity even in the last few million years. Its predominantly Amazonian surface age and isolation in the northern hemisphere away from other volcano-tectonic regions make it an ideal locale to investigate igneous compositions during the most recent geologic period on Mars. Specifically, EVP experienced an extended period of volcanism; compared to large igneous provinces on Earth, the martian context has persisted orders of magnitude longer. Therefore, changes in mantle chemistry, pressure , and temperature are expected, as well as changes in fractional crystallization processes and crustal contamination. Due to the coarse length scale of the observation resolution and lack of resolved local features, these systems appear much simpler than their terrestrial counterpart. In addition, regional scale changes in eruptive processes of any given martian volcanic province over geologic time are still poorly understood. Related investigations are crucial for understanding how the martian crust and mantle have evolved in the absence of Earth-like plate-tectonics. Consequently, this project helps fill this knowledge gap by assessing the compositional evolution of Elysium as a major martian volcanic province, using remote sensing data sets (Mars Odyssey Gamma Ray and neutron Spectrometer suite (GRS), and gravity) and modeling (pet-rologic and thermoelastic). By analyzing data based on predictions from petro-logic modeling, we develop an expansive geologic history for the region that spans over 3 Ga. Our work shows a compositional transition in Elysium's volcan-ism coupled to differences in geologic age between NW and SE regions [1] (mapped Geology summarized in Fig. 1). The continuity of volcanic activity, and the notable spatiotemporal changes in the abundance of heat-producing radioactive elements (K and Th) along with others (Al, Ca, and Fe in particular) make this region an ideal case study for the evolution of volcan-ism on Mars [1,2]. Here we perform a detailed petro-logical and thermoelastic modeling to test the emerging hypothesis that compositional variability within EVP resulted from spatiotemporal changes in the depth of magma formation and present initial results