Unifying Gate Synthesis and Magic State Distillation

The leading paradigm for performing a computation on quantum memories can be encapsulated as distill-then-synthesize. Initially, one performs several rounds of distillation to create high-fidelity magic states that provide one good T gate, an essential quantum logic gate. Subsequently, gate synthesis intersperses many T gates with Clifford gates to realize a desired circuit. We introduce a unified framework that implements one round of distillation and multiquibit gate synthesis in a single step. Typically, our method uses the same number of T gates as conventional synthesis but with the added benefit of quadratic error suppression. Because of this, one less round of magic state distillation needs to be performed, leading to significant resource savings

An enhancement to sea ice motion and age products at the National Snow and Ice Data Center (NSIDC)

A new version of sea ice motion and age products includes several significant upgrades in processing, corrects known issues with the previous version, and updates the time series through 2018, with regular updates planned for the future. First, we provide a history of these NASA products distributed at the National Snow and Ice Data Center. Then we discuss the improvements to the algorithms, provide validation results for the new (Version 4) and older versions, and intercompare the two. While Version 4 algorithm changes were significant, the impact on the products is relatively minor, particularly for more recent years. The changes in Version 4 reduce motion biases by &sim;&thinsp;0.01 to 0.02&thinsp;cm&thinsp;s&minus;1 and error standard deviations by &sim;&thinsp;0.3&thinsp;cm&thinsp;s&minus;1. Overall, ice speed increased in Version 4 over Version 3 by 0.5 to 2.0&thinsp;cm&thinsp;s&minus;1 over most of the time series. Version 4 shows a higher positive trend for the Arctic of 0.21&thinsp;cm&thinsp;s&minus;1 per decade compared to 0.13&thinsp;cm&thinsp;s&minus;1 per decade for Version 3. The new version of ice age estimates indicates more older ice than Version 3, especially earlier in the record, but similar trends toward less multiyear ice. Changes in sea ice motion and age derived from the product show a significant shift in the Arctic ice cover, from a pack with a high concentration of older ice to a sea ice cover dominated by first-year ice, which is more susceptible to summer melt. We also observe an increase in the speed of the ice over the time series &ge;&thinsp;30 years, which has been shown in other studies and is anticipated with the annual decrease in sea ice extent. </div

Exploring and Exploiting Acceptor Preferences of the Human Polysialyltransferases as a Basis for an Inhibitor Screen

Yesα2,8-Linked polysialic acid (polySia) is an oncofoetal antigen with high abundance during embryonic development. It reappears in malignant tumours of neuroendocrine origin. Two polysialyltransferases (polySTs) ST8SiaII and IV are responsible for polySia biosynthesis. During development, both enzymes are essential to control polySia expression. However, in tumours ST8SiaII is the prevalent enzyme. Consequently, ST8SiaII is an attractive target for novel cancer therapeutics. A major challenge is the high structural and functional conservation of ST8SiaII and -IV. An assay system that enables differential testing of ST8SiaII and -IV would be of high value to search for specific inhibitors. Here we exploited the different modes of acceptor recognition and elongation for this purpose. With DMB-DP3 and DMB-DP12 (fluorescently labelled sialic acid oligomers with a degree of polymerisation of 3 and 12, respectively) we identified stark differences between the two enzymes. The new acceptors enabled the simple comparative testing of the polyST initial transfer rate for a series of CMP-activated and N-substituted sialic acid derivatives. Of these derivatives, the non-transferable CMP-Neu5Cyclo was found to be a new, competitive ST8SiaII inhibitor

Suppression of Star Formation in NGC 1266

NGC1266 is a nearby lenticular galaxy that harbors a massive outflow of molecular gas powered by the mechanical energy of an active galactic nucleus (AGN). It has been speculated that such outflows hinder star formation (SF) in their host galaxies, providing a form of feedback to the process of galaxy formation. Previous studies, however, indicated that only jets from extremely rare, high power quasars or radio galaxies could impart significant feedback on their hosts. Here we present detailed observations of the gas and dust continuum of NGC1266 at millimeter wavelengths. Our observations show that molecular gas is being driven out of the nuclear region at Ṁ_(out) ≈ 110M_⊙ yr^(−1), of which the vast majority cannot escape the nucleus. Only 2M_⊙ yr^(−1) is actually capable of escaping the galaxy. Most of the molecular gas that remains is very inefficient at forming stars. The far-infrared emission is dominated by an ultra-compact (≾50 pc) source that could either be powered by an AGN or by an ultra-compact starburst. The ratio of the SF surface density (Σ_(SFR)) to the gas surface density (Σ_(H2)) indicates that SF is suppressed by a factor of ≈ 50 compared to normal star-forming galaxies if all gas is forming stars, and ≈150 for the outskirt (98%) dense molecular gas if the central region is is powered by an ultra-compact starburst. The AGN-driven bulk outflow could account for this extreme suppression by hindering the fragmentation and gravitational collapse necessary to form stars through a process of turbulent injection. This result suggests that even relatively common, low-power AGNs are able to alter the evolution of their host galaxies as their black holes grow onto the M-σ relation

SMA CO(J=6-5) and 435 micron interferometric imaging of the nuclear region of Arp 220

We have used the Submillimeter Array (SMA) to make the first interferometric observations (beam size ~1") of the 12CO J=6-5 line and 435 micron (690 GHz) continuum emission toward the central region of the nearby ULIRG Arp 220. These observations resolve the eastern and western nuclei from each other, in both the molecular line and dust continuum emission. At 435 micron, the peak intensity of the western nucleus is stronger than the eastern nucleus, and the difference in peak intensities is less than at longer wavelengths. Fitting a simple model to the dust emission observed between 1.3 mm and 435 micron suggests that dust emissivity power law index in the western nucleus is near unity and steeper in the eastern nucleus, about 2, and that the dust emission is optically thick at the shorter wavelength. Comparison with single dish measurements indicate that the interferometer observations are missing ~60% of the dust emission, most likely from a spatially extended component to which these observations are not sensitive. The 12CO J=6-5 line observations clearly resolve kinematically the two nuclei. The distribution and kinematics of the 12CO J=6-5 line appear to be very similar to lower J CO lies observed at similar resolution. Analysis of multiple 12CO line intensities indicates that the molecular gas in both nuclei have similar excitation conditions, although the western nucleus is warmer and denser. The excitation conditions are similar to those found in other extreme environments, including M82, Mrk 231, and BR 1202-0725. Simultaneous lower resolution observations of the 12CO, 13CO, and C18O J=2-1 lines show that the 13CO and C18O lines have similar intensities, which suggests that both of these lines are optically thick, or possibly that extreme high mass star formation has produced in an overabundance of C18O.Comment: 13 pages (emulateapj), 10 figures, Accepted for publication in Ap

NANO-IMPRINT TECHNOLOGY COMBINED WITH ROUGH TCO MORPHOLOGY AS DOUBLE TEXTURED LIGHT-TRAPPING SUPERSTRATE FOR THIN FILM SOLAR CELLS

Two types of nano-imprinted 2D grating textures were tested on their light trapping performance for thin film Si tandem solar cells in combination with various TCO’s. The combination with rough TCO layers like LPCVD ZnO leads to double textured superstrates that exhibit at least a similar light trapping capability as the state-of-the-art reference while using thinner TCO layers. Further optimization in combination with nano-imprinted AR textures on the air/glass interface has the potential for >13% devices with thin TCO and absorber layers

Super Star Clusters in the Central Starburst of NGC 4945

The nearby (3.8Mpc) galaxy NGC 4945 hosts a nuclear starburst and Seyfert type 2 active galactic nucleus (AGN). We use the Atacama Large Millimeter/submillimeter Array (ALMA) to image the 93 GHz (3.2 mm) free-free continuum and hydrogen recombination line emission (H40 alpha and H42 alpha) at 2.2 pc (0 12) resolution. Our observations reveal 27 bright, compact sources with FWHM sizes of 1.4-4.0 pc, which we identify as candidate super star clusters. Recombination line emission, tracing the ionizing photon rate of the candidate clusters, is detected in 15 sources, six of which have a significant synchrotron component to the 93 GHz continuum. Adopting an age of similar to 5Myr, the stellar masses implied by the ionizing photon luminosities are log(10) (M*/M-circle dot) approximate to 4.7-6.1. We fit a slope to the cluster mass distribution and find beta = -1.8 +/-.0.4. The gas masses associated with these clusters, derived from the dust continuum at 350 GHz, are typically an order of magnitude lower than the stellar mass. These candidate clusters appear to have already converted a large fraction of their dense natal material into stars and, given their small freefall times of similar to 0.05 Myr, are surviving an early volatile phase. We identify a pointlike source in 93 GHz continuum emission that is presumed to be the AGN. We do not detect recombination line emission from the AGN and place an upper limit on the ionizing photons that leak into the starburst region of Q(0).&lt;.10(52) s(-1)

546 Results from Phase Ib study of tebentafusp (tebe) in combination with durvalumab (durva) and/or tremelimumab (treme) in metastatic cutaneous melanoma (mCM)

BackgroundTebe, a T cell receptor fused to an anti-CD3 effector, can redirect T cells to target gp100+ cells and in Ph3, demonstrated overall survival (OS) benefit as monotherapy in metastatic uveal melanoma. In Ph2, any tumor shrinkage (44% of patients) was a better predictor of OS than response rate. In Ph1, Tebe had monotherapy activity in mCM, also a gp100+ tumor, with 1-year OS ~74% in PD-1 naïve mCM. A Ph1 dose escalation of tebe with durva (anti-PD-L1) and/or treme (anti-CTLA4) was conducted in pre-treated mCM [NCT02535078], with nearly all patients having prior PD1-treatment, and where recently reported therapies have 1-yr OS of ~55%.MethodsHeavily pre-treated HLA-A2+ mCM patients received weekly IV tebe alone (Arm 4) or with increasing doses of durva and/or treme (Arm 1–3) administered IV monthly starting day 15 of each cycle. Primary objective was to identify RP2D of combination therapy. Secondary objectives included adverse events (AE) and efficacy.Results112 pts received ≥1 tebe dose. Median age was 59, 77% were ECOG 0, and 37% were BRAFm (of which 71% received prior BRAFi/MEKi). 91% of pts were 2L+, while 74% were 3L+. 103 (92%) received prior PD-1 inhibitor, of which 87% also received prior ipilimumab. 43 pts received tebe + durva (Arm 1), 13 received tebe + treme (Arm 2), 29 received triplet therapy (Arm 3), and 27 received tebe alone (Arm 4). Maximum target doses of tebe (68 mcg) + durva (20 mg/kg) and treme (1 mg/kg) were tolerated. MTD was not formally identified for any arm. Two DLTs occurred: prolonged grade 3 rash (Arm 1) and grade 2 diarrhea leading to treatment delay (Arm 2). Related AEs that were Grade ≥3 or led to discontinuations were: 44%/0% (Arm 1), 23%/0% (Arm2), 38%/7% (Arm3), 26%/4% (Arm 4). There were no treatment-related deaths.In prior PD-1 pts, tumor shrinkage occurred in 36% and 1-yr OS was 68%. Of 51 evaluable PD-1 resistant pts (best response CR/PR/SD to prior PD1), tumor shrinkage occurred in 28% and 1-yr OS was 73% (figure 1). In 35 evaluable PD-1 refractory pts (prior best response PD), tumor shrinkage occurred in 49% and 1-yr OS was 61%. For 38 prior PD-1 pts who received ≥10mg/kg durva, 1-yr OS was 81%.Abstract 546 Figure 1% tumor change from baseline in evaluable patients with known response to prior PD1 exposureConclusionsTebe with anti-PD-L1 and/or anti-CTLA4 had an acceptable safety profile. Tebe + durva demonstrated durable tumor shrinkage and promising 1-yr OS rates in prior-PD1 treated mCM relative to recent reports.Trial RegistrationNCT02535078Ethics ApprovalThe institutional review board or independent ethics committee at each center approved the trial. The trial was conducted in accordance with the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice guidelines

Dense Gas, Dynamical Equilibrium Pressure, and Star Formation in Nearby Star-Forming Galaxies

We use new ALMA observations to investigate the connection between dense gas fraction, star formation rate, and local environment across the inner region of four local galaxies showing a wide range of molecular gas depletion times. We map HCN (1-0), HCO$^+$ (1-0), CS (2-1), $^{13}$CO (1-0), and C$^{18}$O (1-0) across the inner few kpc of each target. We combine these data with short spacing information from the IRAM large program EMPIRE, archival CO maps, tracers of stellar structure and recent star formation, and recent HCN surveys by Bigiel et al. and Usero et al. We test the degree to which changes in the dense gas fraction drive changes in the SFR. $I_{HCN}/I_{CO}$ (tracing the dense gas fraction) correlates strongly with $I_{CO}$ (tracing molecular gas surface density), stellar surface density, and dynamical equilibrium pressure, $P_{DE}$. Therefore, $I_{HCN}/I_{CO}$ becomes very low and HCN becomes very faint at large galactocentric radii, where ratios as low as $I_{HCN}/I_{CO} \sim 0.01$ become common. The apparent ability of dense gas to form stars, $\Sigma_{SFR}/\Sigma_{dense}$ (where $\Sigma_{dense}$ is traced by the HCN intensity and the star formation rate is traced by a combination of H$\alpha$ and 24$\mu$m emission), also depends on environment. $\Sigma_{SFR}/\Sigma_{dense}$ decreases in regions of high gas surface density, high stellar surface density, and high $P_{DE}$. Statistically, these correlations between environment and both $\Sigma_{SFR}/\Sigma_{dense}$ and $I_{HCN}/I_{CO}$ are stronger than that between apparent dense gas fraction ($I_{HCN}/I_{CO}$) and the apparent molecular gas star formation efficiency $\Sigma_{SFR}/\Sigma_{mol}$. We show that these results are not specific to HCN.Comment: 31 pages, 13 figures, accepted for publication in The Astrophysical Journal, email for access to data table before publicatio