1,969 research outputs found

    Photonic Quantum Logic with Narrowband Light from Single Atoms

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    Increasing control of single photons enables new applications of photonic quantum-enhanced technology and further experimental exploration of fundamental quantum phenomena. Here, we demonstrate quantum logic using narrow linewidth photons that are produced under nearly perfect quantum control from a single ^87Rb atom strongly coupled to a high-finesse cavity. We use a controlled- NOT gate integrated into a photonic chip to entangle these photons, and we observe non-classical correlations between events separated by periods exceeding the travel time across the chip by three orders of magnitude. This enables quantum technology that will use the properties of both narrowband single photon sources and integrated quantum photonics, such as networked quantum computing, narrow linewidth quantum enhanced sensing and atomic memories.Comment: 5 pates, 3 figure

    No evidence of responding individuals constraining the evolution of the pheromone signal in the pine engraver Ips avulsus

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    Chemical signals are important mediators of interactions within forest ecosystems. In insects, pheromone signals mediate intraspecific interactions such as mate location and acceptance. The evolution of pheromones in insects has been mostly studied from a theoretical perspective in the Lepidoptera. With this study, we aimed to broaden our understanding of pheromone communication in bark beetles. We first demonstrated that the enantiomeric ratios of ipsdienol produced by male I. avulsus, showed little variation. Subsequently, with field trapping trials we characterized the influence of the enantiomeric ratio of ipsdienol (pheromone component of I. avulsus) on I. avulsus captures and observed a great amount of variation in the receiver preference function. Most importantly, we demonstrated that responding individuals responded indiscriminately to all the enantiomeric ratios produced by the emitting individuals. These observations are consistent with the asymmetric tracking model which postulates that if the limiting sex is the emitting sex, responding individuals should not discriminate between emitted ratios. Consequently, responding individuals do not constrain the evolution of the signal. Our data suggest that, in I. avulsus, the composition of the aggregation pheromone signal might be more responsive to external selection forces, such as predation and metabolic constraints, as suggested by the asymmetric tracking model.Louisiana State University AgCenter. Open Access provided by Natural Resources Canada.https://link.springer.com/journal/10886hj2023Forestry and Agricultural Biotechnology Institute (FABI)Zoology and Entomolog

    Genetic diversity of the two-spotted stink bug Bathycoelia distincta (Pentatomidae) associated with macadamia orchards in South Africa

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    The South African macadamia industry is severely affected by a complex of stink bugs, dominated by the two-spotted stink bug, Bathycoelia distincta Distant (Pentatomidae). This species was first discovered during the spring of 1984 in the Limpopo province. Although considerable effort has been spent trying to manage this pest, it continues to be a pest of concern for the macadamia industry. Information on the genetic diversity of this species is lacking, despite the potential relevance of such information for management strategies. The present study aimed to characterise the genetic diversity of B. distincta populations in South Africa. The Cytochrome c Oxidase Subunit 1 (COI) and cytochrome b (Cytb) gene regions were sequenced from individuals collected from the three main regions of macadamia production over three different seasons (2018–2020). An overall high haplotype diversity (COI = 0.744, Cytb = 0.549 and COI+Cytb = 0.875) was observed. Pairwise mean genetic distance between populations from each region varied from 0.2–0.4% in both datasets, which suggests the absence of cryptic species. The median joining network for both datasets consisted of one or two central haplotypes shared between the regions in addition to unique haplotypes observed in each region. Finally, low genetic differentiation (FST < 0.1), high gene flow (Nm > 1) and the absence of a correlation between genetic and geographic distance were estimated among populations. Overall, these results suggest that the B. distincta populations are not structured among the areas of macadamia production in South Africa. This might be due to its ability to feed and reproduce on various plants and its high dispersal (airborne) between the different growing regions of the country along with the rapid expansion of macadamia plantations in South Africa.SUPPORTING INFORMATION : FIGURE S1. Isolation by distance of Bathycoelia distincta populations for COI marker (Mantel test, r = 0.731, P > 0.05). FIGURE S2. Isolation by distance of Bathycoelia distincta populations for Cytb marker (Mantel test, r = 0.310, P > 0.05). FIGURE S3. Isolation by distance of Bathycoelia distincta populations for COI+Cytb combined marker (Mantel test, r = 0.669, P > 0.05). TABLE S1. List of the individual for each haplotype generated in the study for the COI marker. TABLE S2. List of the individual for each haplotype generated in the study for the Cytb marker. TABLE S3. List of the individual for each haplotype generated in the study for the COI +Cytb combined markers.The University of Pretoria, the Forestry and Agricultural Biotechnology Institute (FABI), the Centre for Excellence in Plant Biotechnology (CPHB), Macadamia South Africa NPC (SAMAC) and NRF Thuthuka.http://www.plosone.orgdm2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyZoology and Entomolog

    Stem Cell Transplantation As A Dynamical System: Are Clinical Outcomes Deterministic?

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    Outcomes in stem cell transplantation (SCT) are modeled using probability theory. However the clinical course following SCT appears to demonstrate many characteristics of dynamical systems, especially when outcomes are considered in the context of immune reconstitution. Dynamical systems tend to evolve over time according to mathematically determined rules. Characteristically, the future states of the system are predicated on the states preceding them, and there is sensitivity to initial conditions. In SCT, the interaction between donor T cells and the recipient may be considered as such a system in which, graft source, conditioning and early immunosuppression profoundly influence immune reconstitution over time. This eventually determines clinical outcomes, either the emergence of tolerance or the development of graft versus host disease. In this paper parallels between SCT and dynamical systems are explored and a conceptual framework for developing mathematical models to understand disparate transplant outcomes is proposed.Comment: 23 pages, 4 figures. Updated version with additional data, 2 new figures and editorial revisions. New authors adde

    Pheromones as management tools for non-Scolytinae Curculionidae : development and implementation considerations

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    For the large family Curculionidae, the number of species considered pests is expected to increase due to global movement of plant and soil material, as well as climate change. Pheromones are increasingly popular for use in pest management programmes, either as stand-alone tactics or with other management tactics. Biological differences between Curculionidae species often require species-specific optimization of methodologies to successfully collect, identify and integrate pheromones into management programmes. This review aims to provide an overview of current knowledge on non-Scolytinae Curculionidae pheromones and their use in strategies to manage these insects where they are pests. Throughout, we highlight the importance of understanding the chemical ecology of target pests and related species to direct pheromone sampling and the development of pheromone-based management tactics.The Department of Science and Technology National Research Foundation (DST-NRF), the University of Pretoria (UP) and members of the Tree Protection Co-operative Programme (TPCP).http://www.tandfonline.com/loi/tsfs202021-12-14hj2021BiochemistryChemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyZoology and Entomolog

    Impact of intercept trap type on plume structure : a potential mechanism for differential performance of intercept trap designs for Monochamus species

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    Studies have demonstrated that semiochemical-baited intercept traps differ in their performance for sampling insects, but we have an incomplete understanding of how and why intercept trap design effects vary among insects. This can significantly delay both the development of new and optimization of existing survey and detection tools. The development of a mechanistic understanding of why trap performance varies within and among species would mitigate this delay. The primary objective of this study was to develop methods to characterize and compare the odor plumes associated with intercept traps that differ in their performance for forest Coleoptera. We released CO2 and measured fluctuations of this tracer gas from 175-point locations arranged in a 2-by-3-by-2-m grid cuboid downwind of a standard multiple-funnel, a modified multiple-funnel, a panel, a canopy malaise trap, and a blank control (i.e., no trap) in a greenhouse. Significant differences in trapping efficacy between these different trap designs were observed for Monochamus scutellatus (Say) and Monochamus notatus (Drury) in a field trial. Significant differences were also observed in how CO2 accumulated in time at different positions downwind among these different trap designs. Turbulent dispersion is the dominant force structuring odor plumes and creates intermittency in the odor plume that is important for sustained upwind flight in insects. Methodological and instrumental limitations resulted in the inability to determine instantaneous plume structures and vortex shedding frequencies for different intercept trap designs. Although we observed differences in the odor plumes emanating downwind of the different intercept trap designs, we were unable to reconcile these differences with capture rates of the different trap designs for M. scutellatus and M. notatus.The National Research Foundation of South Africa, Natural Resources Canada and USDA—Animal and Plant Health Inspection Service.http://link.springer.com/journal/103402021-02-20hj2020BiochemistryChemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyZoology and Entomolog

    Multimode interferometry for entangling atoms in quantum networks

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    © 2019 IOP Publishing Ltd. We bring together a cavity-enhanced light-matter interface with a multimode interferometer (MMI) integrated onto a photonic chip and demonstrate the potential of such hybrid systems to tailor distributed entanglement in a quantum network. The MMI is operated with pairs of narrowband photons produced a priori deterministically from a single 87Rb atom strongly coupled to a high-finesse optical cavity. Non-classical coincidences between photon detection events show no loss of coherence when interfering pairs of these photons through the MMI in comparison to the two-photon visibility directly measured using Hong-Ou-Mandel interference on a beam splitter. This demonstrates the ability of integrated multimode circuits to mediate the entanglement of remote stationary nodes in a quantum network interlinked by photonic qubits
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