273 research outputs found

    Self-referenced characterization of space-time couplings in near single-cycle laser pulses

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    We report on the characterization of space-time couplings in high energy sub-2-cycle 770nm laser pulses using a self-referencing single-shot method. Using spatially-encoded arrangement filter-based spectral phase interferometry for direct electric field reconstruction (SEA-F-SPIDER) we characterize few-cycle pulses with a wave-front rotation of 2.8x?10^11 rev/sec (1.38 mrad per half-cycle) and pulses with pulse front tilts ranging from to -0.33 fs/um to -3.03 fs/um.Comment: 6 pages, 6 figure

    Health from the Grassroots, Listening to Mob: University- Based Aboriginal Researchers Collaborate with Aboriginal Communities to Identify Health Priorities

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    Background: There is opportunity for Universities to actively engage with Aboriginal communities to participate, conduct, and ideally lead, responsible research that attends to community priorities and issues. The Health from the Grassroots (Grassroots) project seeks to address an ongoing mismatch between university-defined priorities and community-defined priorities in rural [***]. Grassroots, led by Aboriginal staff of the [***], is a community engagement project aimed at engaging Aboriginal communities in conversations to inform research priorities. This paper describes the project vision, implementation, and lessons learned in the first years. Approach: The Grassroots project was a true representation of collaborative research led by and for Aboriginal people. We designed and conducted a local survey and yarning sessions with community members and used this information to design a “rich picture” to report findings and engage in further conversation with communities about evolving health and research priorities. We identified strengths and challenges faced by communities and health services in the region. The Aboriginal research team centred community in decision-making for project design and direction. Lessons Learned: Challenges encountered included limited resources and devoted time for the research team as this project occurred alongside staffs’ substantive positions. Community members were highly engaged in the consultation process and the rich picture continues to be used to further conversations about research action. Conclusions: Deep-rooted relationships and identities as members of the Community in which we live, and work enabled meaningful consultation to inform research action. Research priorities identified through the Grassroots project have been integrated into the ongoing work of the [***]

    Secure Autonomous Automated Scheduling (SAAS)

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    This report describes network-centric operations, where a virtual mission operations center autonomously receives sensor triggers, and schedules space and ground assets using Internet-based technologies and service-oriented architectures. For proof-of-concept purposes, sensor triggers are received from the United States Geological Survey (USGS) to determine targets for space-based sensors. The Surrey Satellite Technology Limited (SSTL) Disaster Monitoring Constellation satellite, the UK-DMC, is used as the space-based sensor. The UK-DMC's availability is determined via machine-to-machine communications using SSTL's mission planning system. Access to/from the UK-DMC for tasking and sensor data is via SSTL's and Universal Space Network's (USN) ground assets. The availability and scheduling of USN's assets can also be performed autonomously via machine-to-machine communications. All communication, both on the ground and between ground and space, uses open Internet standard

    Carrier-envelope phase stability of hollow-fibers used for high-energy, few-cycle pulse generation

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    We investigated the carrier-envelope phase (CEP) stability of a hollow-fiber setup used for high-energy, few-cycle pulse generation. Saturation of the output pulse energy is observed at 0.6 mJ for a 260 um inner-diameter, 1 m long fiber, statically filled with neon, with the pressure adjusted to achieve an output spectrum capable of supporting sub-4fs pulses. The maximum output pulse energy can be increased to 0.8mJ by using either differential pumping, or circularly polarized input pulses. We observe the onset of an ionization-induced CEP instability, which does not increase beyond an input pulse energy of 1.25 mJ due to losses in the fiber caused by ionization. There is no significant difference in the CEP stability with differential pumping compared to static-fill, demonstrating that gas flow in differentially pumped fibers does not degrade the CEP stabilization.Comment: 4 pages, 4 figure

    MPA_Pathway_Tool: User-Friendly, Automatic Assignment of Microbial Community Data on Metabolic Pathways

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    Taxonomic and functional characterization of microbial communities from diverse environments such as the human gut or biogas plants by multi-omics methods plays an ever more important role. Researchers assign all identified genes, transcripts, or proteins to biological pathways to better understand the function of single species and microbial communities. However, due to the versality of microbial metabolism and a still-increasing number of newly biological pathways, linkage to standard pathway maps such as the KEGG central carbon metabolism is often problematic. We successfully implemented and validated a new user-friendly, stand-alone web application, the MPA_Pathway_Tool. It consists of two parts, called ‘Pathway-Creator’ and ‘Pathway-Calculator’. The ‘Pathway-Creator’ enables an easy set-up of user-defined pathways with specific taxonomic constraints. The ‘Pathway-Calculator’ automatically maps microbial community data from multiple measurements on selected pathways and visualizes the results. The MPA_Pathway_Tool is implemented in Java and ReactJS

    The Dynamics of Poor Systems of Galaxies

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    We assemble and observe a sample of poor galaxy systems that is suitable for testing N-body simulations of hierarchical clustering (Navarro, Frenk, & White 1997; NFW) and other dynamical halo models (e.g., Hernquist 1990). We (1) determine the parameters of the density profile rho(r) and the velocity dispersion profile sigma(R), (2) separate emission-line galaxies from absorption-line galaxies, examining the model parameters and as a function of spectroscopic type, and (3) for the best-behaved subsample, constrain the velocity anisotropy parameter, beta, which determines the shapes of the galaxy orbits. The NFW universal profile and the Hernquist (1990) model both provide good descriptions of the spatial data. In most cases an isothermal sphere is ruled out. Systems with declining sigma(R) are well-matched by theoretical profiles in which the star-forming galaxies have predominantly radial orbits (beta > 0); many of these galaxies are probably falling in for the first time. There is significant evidence for spatial segregation of the spectroscopic classes regardless of sigma(R).Comment: 36 pages, 20 figures, and 5 tables. To appear in the Astrophysical Journa

    Crystallographic dissection of the spliceosomal snRNP structures

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    NANO-SQUIDs based on niobium Dayem bridges for nanoscale applications

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    Abstract. We report on the design, the fabrication and the performance of an integrated magnetic nano-sensor based on niobium dc-SQUID (Superconducting QUantum Interference Device) for nanoscale applications is presented. The nano-sensors are based on nanometric niobium constrictions (Dayem bridges) inserted in a square loop having a side length of 200 nm. Measurements of voltage-flux characteristic, flux to voltage transfer factor and noise performances are reported. In small signal mode, the sensors have shown a magnetic flux noise spectral density of 1.5 ”Ί0/Hz1/2 corresponding to a spin sensitivity in unit of Bohr magneton of 60 spin/Hz1/2. Supercurrent decay measurements of these devices are also reported. Such measurements provide useful information for applications which employ the SQUID as a trigger where the sensor works on the zero voltage state. The experimental data, have shown an intrinsic current fluctuation less than 0.2% of the critical current at liquid helium temperature, corresponding to an intrinsic sensor magnetic flux resolution of a few mΊ0. In view of the nano-SQUID employments in the detection of small spin populations, the authors calculated the spin sensitivity and the magnetic response relative to the single spin, as a function of its position within the SQUID hole. The results show that the SQUID response depends strongly on the spin position

    Participants’ experiences of AVATAR therapy for distressing voices: a thematic qualitative evaluation

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    Background: AVATAR therapy is an innovative therapy designed to support people with distressing voices. Voice hearers co-create a digital representation of their voice and engage in dialogue with it. Although it has been successfully tested in a powered randomised controlled trial (ISRCTN65314790), the participants’ experience of this therapy has not been yet evaluated. We aimed to explore enablers and barriers to engagement with the therapy and potential for real-world impact on distressing voices. Methods: Thirty per cent of those who completed AVATAR therapy (15 people in total) and 5 who dropped out from therapy within the main AVATAR RCT were invited to participate in a semi-structured interview, which was audio-recorded and subsequently transcribed. Results: Fourteen therapy completers (28% of the full sample) and one person who dropped out of therapy after 1 active session, were interviewed. Thematic analysis was used to explore the interviews. A total of 1276 references were coded, and five overarching themes identified: AVATAR therapy set-up; voice embodiment and associated emotions; working in a safe space (supported by the therapist); learning new ways of relating to the voices; impact of therapy on everyday life. Overall, the therapy set-up, with its digital components and its distinctive features as compared with common face-to-face talking therapies, was satisfactory. The inclusion of technology was well accepted as both a means to deliver the therapy and a tool to create a digital representation of the person’s distressing voice. The co-creation of the avatar and the enactment of the relationship between the person and the voice were perceived as a very helpful process to promote the therapeutical dialogue. Participants reported engaging well with the therapist and feeling supported and identified specific learnt strategies to deal with the voices and how they have had an impact on everyday life. Conclusions: AVATAR therapy is acceptable and provides benefit for participants with psychosis. Our results highlighted the enablers and challenges of working dialogically with distressing voices using a digital representation and dealing with highly demanding emotional, cognitive, and relational processes linked to the experience. Our analysis also identified the core strategies learnt by participants and how these were generalised to their daily life resulting into a positive change in different domains, and in particular broader social relationships

    Memo1 binds reduced copper ions, interacts with copper chaperone Atox1, and protects against copper-mediated redox activity in\ua0vitro

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    The protein mediator of ERBB2-driven cell motility 1 (Memo1) is connected to many signaling pathways that play key roles in cancer. Memo1 was recently postulated to bind copper (Cu) ions and thereby promote the generation of reactive oxygen species (ROS) in cancer cells. Since the concentration of Cu as well as ROS are increased in cancer cells, both can be toxic if not well regulated. Here, we investigated the Cu-binding capacity of Memo1 using an array of biophysical methods at reducing as well as oxidizing conditions in\ua0vitro. We find that Memo1 coordinates two reduced Cu (Cu(I)) ions per protein, and, by doing so, the metal ions are shielded from ROS generation. In support of biological relevance, we show that the cytoplasmic Cu chaperone Atox1, which delivers Cu(I) in the secretory pathway, can interact with and exchange Cu(I) with Memo1 in\ua0vitro and that the two proteins exhibit spatial proximity in breast cancer cells. Thus, Memo1 appears to act as a Cu(I) chelator (perhaps shuttling the metal ion to Atox1 and the secretory path) that protects cells from Cu-mediated toxicity, such as uncontrolled formation of ROS. This Memo1 functionality may be a safety mechanism to cope with the increased demand of Cu ions in cancer cells
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