Quasi-period outflows observed by the X-Ray Telescope onboard Hinode in the boundary of an active region

Persistent outflows have recently been detected at boundaries of some active regions. Although these outflows are suggested to be possible sources of the slow solar wind, the nature of these outflows is poorly understood. Through an analysis of an image sequence obtained by the X-Ray Telescope onboard the Hinode spacecraft, we found that quasi-period outflows are present in the boundary of an active region. The flows are observed to occur intermittently, often with a period of 5-10 minutes. The projected flow speed can reach more than 200 km/s, while its distribution peaks around 50 km/s. This sporadic high-speed outflow may play an important role in the mass loading process of the slow solar wind. Our results may imply that the outflow of the slow solar wind in the boundary of the active region is intermittent and quasi-periodic in nature.Comment: 5 figures, accepted by RA

Learning to infer: RL-based search for DNN primitive selection on Heterogeneous Embedded Systems

Deep Learning is increasingly being adopted by industry for computer vision applications running on embedded devices. While Convolutional Neural Networks' accuracy has achieved a mature and remarkable state, inference latency and throughput are a major concern especially when targeting low-cost and low-power embedded platforms. CNNs' inference latency may become a bottleneck for Deep Learning adoption by industry, as it is a crucial specification for many real-time processes. Furthermore, deployment of CNNs across heterogeneous platforms presents major compatibility issues due to vendor-specific technology and acceleration libraries. In this work, we present QS-DNN, a fully automatic search based on Reinforcement Learning which, combined with an inference engine optimizer, efficiently explores through the design space and empirically finds the optimal combinations of libraries and primitives to speed up the inference of CNNs on heterogeneous embedded devices. We show that, an optimized combination can achieve 45x speedup in inference latency on CPU compared to a dependency-free baseline and 2x on average on GPGPU compared to the best vendor library. Further, we demonstrate that, the quality of results and time "to-solution" is much better than with Random Search and achieves up to 15x better results for a short-time search

Small Business Financing: Survey Evidence in West Texas

We investigate the financial sources of small firms through a survey of sample firms from West Texas. Evidence shows that the two most common start-up financing alternatives are personal savings and commercial bank loans. Commercial banks remain the most popular source of financing for present and future needs, followed by leasing companies and credit unions. Informal types of financing such as business credit cards, and trade credit are used in addition to lines of credit for transaction and working capital purposes. Firms typically review their financial performance monthly and use common cash balances as the primary financial tool

Thin film superfluid optomechanics

Excitations in superfluid helium represent attractive mechanical degrees of freedom for cavity optomechanics schemes. Here we numerically and analytically investigate the properties of optomechanical resonators formed by thin films of superfluid $^4$He covering micrometer-scale whispering gallery mode cavities. We predict that through proper optimization of the interaction between film and optical field, large optomechanical coupling rates $g_0>2\pi \times 100$ kHz and single photon cooperativities $C_0>10$ are achievable. Our analytical model reveals the unconventional behaviour of these thin films, such as thicker and heavier films exhibiting smaller effective mass and larger zero point motion. The optomechanical system outlined here provides access to unusual regimes such as $g_0>\Omega_M$ and opens the prospect of laser cooling a liquid into its quantum ground state.Comment: 18 pages, 6 figure

Microphotonic Forces From Superfluid Flow

In cavity optomechanics, radiation pressure and photothermal forces are widely utilized to cool and control micromechanical motion, with applications ranging from precision sensing and quantum information to fundamental science. Here, we realize an alternative approach to optical forcing based on superfluid flow and evaporation in response to optical heating. We demonstrate optical forcing of the motion of a cryogenic microtoroidal resonator at a level of 1.46 nN, roughly one order of magnitude larger than the radiation pressure force. We use this force to feedback cool the motion of a microtoroid mechanical mode to 137 mK. The photoconvective forces demonstrated here provide a new tool for high bandwidth control of mechanical motion in cryogenic conditions, and have the potential to allow efficient transfer of electromagnetic energy to motional kinetic energy.Comment: 5 pages, 6 figure

Poxviruses in bats … so what?

Poxviruses are important pathogens of man and numerous domestic and wild animal species. Cross species (including zoonotic) poxvirus infections can have drastic consequences for the recipient host. Bats are a diverse order of mammals known to carry lethal viral zoonoses such as Rabies, Hendra, Nipah, and SARS. Consequent targeted research is revealing bats to be infected with a rich diversity of novel viruses. Poxviruses were recently identified in bats and the settings in which they were found were dramatically different. Here, we review the natural history of poxviruses in bats and highlight the relationship of the viruses to each other and their context in the Poxviridae family. In addition to considering the zoonotic potential of these viruses, we reflect on the broader implications of these findings. Specifically, the potential to explore and exploit this newfound relationship to study coevolution and cross species transmission together with fundamental aspects of poxvirus host tropism as well as bat virology and immunology

Modelling of vorticity, sound and their interaction in two-dimensional superfluids

Vorticity in two-dimensional superfluids is subject to intense research efforts due to its role in quantum turbulence, dissipation and the BKT phase transition. Interaction of sound and vortices is of broad importance in Bose-Einstein condensates and superfluid helium [1-4]. However, both the modelling of the vortex flow field and of its interaction with sound are complicated hydrodynamic problems, with analytic solutions only available in special cases. In this work, we develop methods to compute both the vortex and sound flow fields in an arbitrary two-dimensional domain. Further, we analyse the dispersive interaction of vortices with sound modes in a two-dimensional superfluid and develop a model that quantifies this interaction for any vortex distribution on any two-dimensional bounded domain, possibly non-simply connected, exploiting analogies with fluid dynamics of an ideal gas and electrostatics. As an example application we use this technique to propose an experiment that should be able to unambiguously detect single circulation quanta in a helium thin film.Comment: 23 pages, 8 figure

The Role of Apoptosis in Thyroid Autoimmunity

There is increasing evidence showing that apoptosis plays a role in the development of the autoimmune thyroid diseases—Hashimoto's (lymphocytic) thyroiditis (HT) and Graves' disease (GD). The immune pathogenesis of HT and GD is not yet fully understood, but evidence points toward several steps. A defect in CD4+CD25+ T regulatory cells breaks the immunological tolerance of the host and induces an abnormal production of cytokines, which facilitates the initiation of apoptosis. Though apoptosis appears to play a role in the pathogenesis of both HT and GD, the mechanisms that mediate these processes appear different. The induction of apoptosis in HT results in the destruction of thyrocytes, while apoptosis in the GD leads to damage of thyroid-infiltrating lymphocytes. The differences in the apoptotic mechanisms produce two very different forms of thyroid autoimmune responses, eventually developing into HT and GD, respectively.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63177/1/thy.2007.0208.pd

Decision-making for the demolition or adaptation of buildings

This paper considers why the decision may be made either to demolish or adapt existing buildings on brownfield sites and compares real-life decisions to those produced by theoretical design-support tools. Five case studies, including three individual buildings and two master plan sites of multiple buildings, were investigated through interviews with stakeholders. Reasons for retention included heritage value, architectural quality and government incentives, while reasons for demolition included maximising land value, lack of architectural significance and poor building condition. The analysis showed that the theoretical tools were useful for their intended purpose of analysing a portfolio of assets but that they could be improved by providing higher weightings for heritage values and extending the tools to assess different end uses and forms of adaptation. By testing the tools on master plan sites, the paper also identifies urban design variables, such as land efficiency, which would need to be incorporated for this purpose.The authors gratefully acknowledge the Engineering and Physical Sciences Research Council (EPSRC) for funding this research through the EPSRC Centre for Doctoral Training in Future Infrastructure and Built Environment (EPSRC grant reference number EP/L016095/1)