Quantum coherent control of highly multipartite continuous-variable entangled states by tailoring parametric interactions

The generation of continuous-variable multipartite entangled states is important for several protocols of quantum information processing and communication, such as one-way quantum computation or controlled dense coding. In this article we theoretically show that multimode optical parametric oscillators can produce a great variety of such states by an appropriate control of the parametric interaction, what we accomplish by tailoring either the spatio-temporal shape of the pump, or the geometry of the nonlinear medium. Specific examples involving currently available optical parametric oscillators are given, hence showing that our ideas are within reach of present technology.Comment: 14 pages, 5 figure

Viral suppression among persons in HIV care in the United States during 2009–2013: sampling bias in Medical Monitoring Project surveillance estimates

Purpose: To assess sampling bias in national viral suppression (VS) estimates derived from the Medical Monitoring Project (MMP) resulting from use of an abbreviated (four-month) annual sampling period. We aimed to improve VS estimates using cohort data from the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) and a novel cohort-adjustment method. Methods: Using full calendar years of NA-ACCORD data, we assessed timing of HIV care attendance (inside vs. exclusively outside MMP's four-month sampling period), VS status at last test (<200 vs. ≥200 copies/mL), and associated demographics. These external estimates were used to standardize MMP to NA-ACCORD data with multivariable regression models of care attendance and VS, yielding adjusted 2009–2013 VS estimates with 95% confidence intervals. Results: Weighted percentages of VS among persons in HIV care were 67% in 2009 and 77% in 2013. These estimates are slightly lower than previously published MMP estimates (72% and 80% in 2009 and 2013, respectively). The number of persons receiving HIV care was previously underestimated by 20%, because patients receiving care exclusively outside the MMP sampling period did not contribute toward the weighted population estimate. Conclusions: Careful examination of national surveillance estimates using data triangulation and novel methodologies can improve the robustness of VS estimates

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

14 p.Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

Use of muscarinic toxins, mtx1, mtx2 and mtx3, in the study of synaptic transmission in the peripheral nervous system

Abstract of poster presentation on the use of muscarinic toxins in the study of synaptic transmission in the peripheral nervous system. Presented at the Seventh International Symposium of Subtypes of Muscarinic Receptors. Vienna, Virginia, USA, 12 November - 15 November 1996

Geologic expressions of contemporary and paleo-liquefaction: Insights into strong ground motion and site characteristics

Recurrent liquefaction in Christchurch during the 2010-2011 Canterbury earthquake sequence created a wealth of shallow subsurface intrusions with geometries and orientations governed by (1) strong ground motion severity and duration, and (2) intrinsic site characteristics including liquefaction susceptibility, lateral spreading severity, geomorphic setting, host sediment heterogeneity, and anthropogenic soil modifications. We present a suite of case studies that demonstrate how each of these characteristics influenced the geologic expressions of contemporary liquefaction in the shallow subsurface. We compare contemporary features with paleo-features to show how geologic investigations of recurrent liquefaction can provide novel insights into the shaking characteristics of modern and paleo-earthquakes, the influence of geomorphology on liquefaction vulnerability, and the possible controls of anthropogenic activity on the geologic record. We conclude that (a) sites of paleo-liquefaction in the last 1000-2000 years corresponded with most severe liquefaction during the Canterbury earthquake sequence, (b) less vulnerable sites that only liquefied in the strongest and most proximal contemporary earthquakes are unlikely to have liquefied in the last 1000-2000 years or more, (c) proximal strong earthquakes with large vertical accelerations favoured sill formation at some locations, (d) contemporary liquefaction was more severe than paleoliquefaction at all study sites, and (e) stratigraphic records of successive dike formation were more complete at sites with severe lateral spreading, (f) anthropogenic fill suppressed surface liquefaction features and altered subsurface liquefaction architecture

Agonist-induced phasic and tonic responses in smooth muscle are mediated by InsP3

Many cellular functions are regulated by agonist-induced InsP3-evoked Ca2+ release from the internal store. In non-excitable cells, predominantly, the initial Ca2+ release from the store by InsP3 is followed by a more sustained elevation in [Ca2+]i via store-operated Ca2+ channels as a consequence of depletion of the store. Here, in smooth muscle, we report that the initial transient increase in Ca2+, from the internal store, is followed by a sustained response also as a consequence of depletion of the store (by InsP3), but, influx occurs via voltage-dependent Ca2+ channels. Contractions were measured in pieces of whole distal colon and membrane currents and [Ca2+]i in single colonic myocytes. Carbachol evoked phasic and tonic contractions; only the latter were abolished in Ca2+-free solution. The tonic component was blocked by the voltage-dependent Ca2+ channel blocker nimodipine but not by the store-operated channel blocker SKF 96365. InsP3 receptor inhibition, with 2-APB, attenuated both the phasic and tonic components. InsP3 may regulate tonic contractions via sarcolemma Ca2+ entry. In single cells, depolarisation (to ~-20 mV) elevated [Ca2+]i and activated spontaneous transient outward currents (STOCs). CCh suppressed STOCs, as did caffeine and InsP3. InsP3 receptor blockade by 2-APB or heparin prevented CCh suppression of STOCs; protein kinase inhibition by H-7 or PKC19-36 did not. InsP3 suppressed STOCs by depleting a Ca2+ store accessed separately by the ryanodine receptor (RyR). Thus depletion of the store by RyR activators abolished the InsP3-evoked Ca2+ transient. RyR inhibition (by tetracaine) reduced only STOCs but not the InsP3 transient. InsP3 contributes to both phasic and tonic contractions. In the former, muscarinic receptor-evoked InsP3 releases Ca2+ from an internal store accessed by both InsP3 and RyR. Depletion of this store by InsP3 alone suppresses STOCs, depolarises the sarcolemma and permits entry of Ca2+ to generate the tonic component. Therefore, by lowering the internal store Ca2+ content, InsP3 may generate a sustained smooth muscle contraction. These results provide a mechanism to account for phasic and tonic smooth muscle contraction following receptor activation

Cyclic ADP-ribose increases Ca2+ removal in smooth muscle

Ca2+ release via ryanodine receptors (RyRs) is vital in cell signalling and regulates diverse activities such as gene expression and excitation-contraction coupling. Cyclic ADP ribose (cADPR), a proposed modulator of RyR activity, releases Ca2+ from the intracellular store in sea urchin eggs but its mechanism of action in other cell types is controversial. In this study, caged cADPR was used to examine the effect of cADPR on Ca2+ signalling in single voltage-clamped smooth muscle cells that have RyR but lack FKBP12.6, a proposed target for cADPR. Although cADPR released Ca2+ in sea urchin eggs (a positive control), it failed to alter global or subsarcolemma [Ca2+]c, to cause Ca2+-induced Ca2+ release or to enhance caffeine responses in colonic myocytes. By contrast, caffeine (an accepted modulator of RyR) was effective in these respects. The lack of cADPR activity on Ca2+ release was unaffected by the introduction of recombinant FKBP12.6 into the myocytes. Indeed in western blots, using brain membrane preparations as a source of FKBP12.6, cADPR did not bind to FKBPs, although FK506 was effective. However, cADPR increased and its antagonist 8-bromo-cADPR slowed the rate of Ca2+ removal from the cytoplasm. The evidence indicates that cADPR modulates [Ca2+]c but not via RyR; the mechanism may involve the sarcolemma Ca2+ pump