314 research outputs found

    Safety Evaluation of 2+1 Roadway Design

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    An assessment and analysis of the safety of 2+1 roads introduced in 2013 and later

    Innovative Methods to Strengthen Internal KYTC Communications

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    Communication is the linchpin of every organization. Poor communication leads to inefficiencies, frustration among staff, and employee disaffection and disengagement. Although some state transportation agencies have adopted comprehensive strategic plans for internal communications, many have taken a more piecemeal approach, with some Offices and units (e.g., incident management) developing their own plans that apply only to their operations. The latter approach is less than ideal because establishing a comprehensive communications plan provides an organizing framework for all communications within an organization and is critical for uniting staff around a shared sense of purpose and equipping them with the tools they need to realize the organization’s mission and vision. Crafting a solid communications plan also helps to clarify responsibilities, map information flows, break down informational and disciplinary silos, and strengthen employee engagement. If the Kentucky Transportation Cabinet (KYTC) were to embark on the development of a strategic plan for internal communications, it would benefit from adopting several best practices: (1) treating communication as a core competency, (2) improving mentorship opportunities, (3) minimizing clutter by eliminating information redundancies and cutting extraneous content from messages, and (4) seizing opportunities to build employee engagement throughout the agency. As a precursor to developing the communications plan, the Cabinet would benefit from conducting a thorough communications audit to identify communication strengths and weaknesses and identify performance metrics to measure the effectiveness of communications. If a plan was formally adopted, KYTC staff would need to devise a communications toolbox that contains strategies and tactics for increasing engagement and streamlining information flows. Regular performance assessments can be used to identify when and how the communications plan and toolkit should be updated

    Optimized optomechanical crystal cavity with acoustic radiation shield

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    We present the design of an optomechanical crystal nanobeam cavity that combines finite-element simulation with numerical optimization, and considers the optomechanical coupling arising from both moving dielectric boundaries and the photo-elastic effect. Applying this methodology results in a nanobeam with an experimentally realized intrinsic optical Q-factor of 1.2x10^6, a mechanical frequency of 5.1GHz, a mechanical Q-factor of 6.8x10^5 (at T=10K), and a zero-point-motion optomechanical coupling rate of g=1.1MHz.Comment: 4 pages, 4 figure

    2+1 Roadway Design Guidance Update

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    The frequency and severity of crashes on rural two-lane roadways have increased in the US relative to other road types. This trend can be explained by the growing number of vehicles, higher speeds, narrow shoulders, and vehicle mixes. One solution for improving traffic flow and safety outcomes on rural two-lane roadways is to adopt a 2+1 design, which confers the benefits of four-lane highways but at a lower cost. Transportation agencies throughout Europe — and increasingly the US — have seen good results from 2+1 layouts. Crash data from Sweden, Germany, Finland, and Denmark reveal better safety outcomes following the implementation of 2+1 designs, with reductions in fatal and fatal and injury crash rates of 25 – 80 percent. Studies in the United States have found crash declines of 35 – 44 percent following the transition to 2+1 layouts. Over the past 10 years, the Kentucky Transportation Cabinet (KYTC) has built several 2+1 roadways. Evaluations of three 2+1 segments in the state found lower crash rates on two segments, however, not enough crash data are available to draw definitive conclusions. Despite this lack of confirmatory data, there is consensus among practitioners that 2+1 designs hold considerable promise for improving rural roadway operations. Building off of 2+1 guidance originally issued by KYTC in 2013, this report outlines updated policies that account for lessons learned at the agency during the design and construction of 2+1 roadways as well as best practices adopted by other states

    Two-dimensional phononic-photonic bandgap optomechanical crystal cavity

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    We present the fabrication and characterization of an artificial crystal structure formed from a thin-film of silicon which has a full phononic bandgap for microwave X-band phonons and a two-dimensional pseudo-bandgap for near-infrared photons. An engineered defect in the crystal structure is used to localize optical and mechanical resonances in the bandgap of the planar crystal. Two-tone optical spectroscopy is used to characterize the cavity system, showing a large vacuum coupling rate of 220kHz between the fundamental optical cavity resonance at 195THz and a co-localized mechanical resonance at 9.3GHz.Comment: 4 pages, 4 figure

    Tipping the Balance: Factors That Influence the ER Signaling Network in Breast Cancer

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    <p>The estrogen receptor(ER) is a master transcriptional regulator of the breast where it plays key roles in the development and maintenance of normal breast epithelium but is also critical to the growth of luminal breast cancers. ER is also a well-defined molecular therapeutic target and anti-estrogens, such as tamoxifen, are used clinically to inhibit the mitogenic activity of ER and delay disease progression. However, despite the initial benefits to tamoxifen therapy, nearly one third of luminal breast cancer tumors eventually become resistant, limiting the therapeutic utility the drug. Mechanisms of resistance can be attributed to circumvention of ER and reliance on alternative growth pathways, or through upregulation of pathways that converge with ER to allow reactivation. Understanding the molecular determinants of resistance is a critical endeavor that demands attention in order to shape new drug developments and extend the therapeutic efficacy of anti-estrogens.</p><p> A major challenge in elucidating mechanisms of resistance is in understanding the complexities of the ER signaling program in respect to receptor occupancy and the coordinated relationship with chromatin architecture and collaborating transcription factors. This work therefore integrates the relationship between accessible chromatin, as measured by DNase-Seq, with ER occupancy and ER-mediated transcription in an in vivo derived tamoxifen resistant cell line (TamR) and a comparator group of two closely related tamoxifen sensitive cell lines. Cumulatively, these data demonstrate an enhanced role for FOXA1 in tamoxifen resistance. Specifically, FOXA1 occupancy is greatly enriched at differential DNase hypersensitive loci in TamR cells, and FOXA1 target genes are dramatically upregulated. Furthermore, expression of these target genes can be restored to MCF7 levels with siRNA directed against FOXA1. The TamR cells also have increased ER occupancy at FOXA1 overlapping sites, where ER is engaged to chromatin in a ligand-independent manner and results in enhanced activation of nearby target genes that can be repressed with the pure anti-estrogen, ICI. The increased role of FOXA1 is not due to an increase in total protein levels however and instead is manifested through increased activity. </p><p>Other clinical associations of resistance have been elucidated for which there is little to no mechanistic evidence currently available. HOXB13 has been shown to associate with tamoxifen therapy failure from differential microarray expression profiling of patients who relapsed compared to those that remained disease-free at the five year follow-up. The outcome of our studies reveals HOXB13 to downregulate GATA3 levels, which in turn leads to loss of ER function and parallel activation of inflammatory pathways. </p><p>The present study also makes use of publicly available clinical datasets to generate an integrative database of 4885 patients from 25 independent studies. Furthermore, analytical methods and functions were also developed to allow efficient use and application of the data. Access to the breast cancer meta-set and functions are made available to end users via a web interface, GeneAnalytics. Together, the breast cancer meta-set and associated access through the GeneAnalytics web sites provides novel opportunities for researchers to integrate functional studies with tumor derived expression data to further our understanding of cancer related processes.</p><p>Collectively, our findings demonstrate that the ER signaling program is modified as tumors progress to resistance by an increased role of FOXA1 to facilitate ER binding and reprogramming, and by HOXB13 to suppress the actions of ER and promote inflammatory pathways. These mechanisms highlight distinct methods of resistance and provide rational for new therapeutic approaches to extend the utility of current anti-estrogens.</p>Dissertatio

    Observation of Quantum Motion of a Nanomechanical Resonator

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    In this Letter we use resolved sideband laser cooling to cool a mesoscopic mechanical resonator to near its quantum ground state (phonon occupancy 2.6±0.2), and observe the motional sidebands generated on a second probe laser. Asymmetry in the sideband amplitudes provides a direct measure of the displacement noise power associated with quantum zero-point fluctuations of the nanomechanical resonator, and allows for an intrinsic calibration of the phonon occupation number

    Overview of Performance Based Practical Design

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    State transportation agencies (STAs) have increasingly turned to practical design and performance based practical design (PBPD) to inform project development and implementation — and to reduce project costs while optimizing systemwide benefits. PBPD is a design-up philosophy that encourages agencies to formulate projects to meet the purpose and need rather than adhering to ostensibly immutable design standards. This paper reviews practical design and PBPD concepts and initiatives and their application in a variety of contexts. It also summarizes best practices STAs can use to develop a PBPD program. As a holistic approach to project design, PBPD underscores context sensitive solutions that balance the needs of all roadway users, including motorists, bicyclists, and pedestrians. Common PBPD solutions include opting for low-cost enhancements, such as striping, signing, and rumble strips, as opposed to realignment; narrowing shoulder widths; redesigning projects to lower right-of-way costs; modifying interchange designs; and using design exceptions to build projects that fulfill project objectives. STAs committed to establishing robust PBPD programs will typically require 18 to 24 months to get a program off the ground. For an initiative to succeed, it is critical for executive leadership in an agency to advocate for PBPD; that agency staff learn about practical design and ongoing PBPD programs in other states; that a baseline performance evaluation of the tools, concepts, and resources currently used for project development be conducted; and that changes made to the project development process are thoroughly documented. The report closes with a series of recommended performance metrics the Kentucky Transportation Cabinet should consider adopting to improve its monitoring of critical bridge and roadway assets

    Nonlinear radiation pressure dynamics in an optomechanical crystal

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    Utilizing a silicon nanobeam optomechanical crystal, we investigate the attractor diagram arising from the radiation pressure interaction between a localized optical cavity at λ=1552\lambda = 1552nm and a mechanical resonance at ω/2π=3.72\omega/2\pi = 3.72GHz. At a temperature of T≈10T \approx 10K, highly nonlinear driving of mechanical motion is observed via continuous wave optical pumping. Introduction of a time-dependent (modulated) optical pump is used to steer the system towards an otherwise inaccessible dynamically stable attractor in which mechanical self-oscillation occurs for an optical pump red-detuned from the cavity resonance. An analytical model incorporating thermo-optic effects due to optical absorption heating is developed, and found to accurately predict the measured device behavior.Comment: 5 pages, 3 figure

    Review of Project Development Practices and Project Management Resources at State Transportation Agencies

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    At the Kentucky Transportation Cabinet’s (KYTC) Department of Highways, project development encompasses all the work activities needed to move a transportation project from concept and project initiation to construction letting. Developing projects efficiently requires the adoption of sound project management practices. And having recourse to validated project development practices is critical for helping KYTC project managers negotiate the variety of tasks and processes leading up to project implementation and delivery. For a project manager to be successful, they must possess a holistic understanding of how the complex interplay of engineering, environmental, and economic issues affect different stages and facets of project development. Without an expansive knowledge of these variables, project managers risk privileging one area over another, which leads to the development of subject-matter silos that impede efforts to develop a big-picture understanding of a project. Although KYTC has a long track record of executing complex transportation projects, doing so is becoming increasingly challenging due to staff attrition and the attendant loss of institutional knowledge. Today, entry- and mid-level project managers have more project development responsibilities than ever but lack a dependable source of guidance they can turn to that will help them champion projects from the development stage and through to completion. Given staffing and budget constraints, it is more important than ever that KYTC project managers be equipped with all the tools necessary to successfully develop and deliver the construction program. As part of this project to develop A Guidebook for Project Development, the research team has reviewed literature on project management organizational structure and state transportation agency (STA) organizational structures, particularly those that have explicit project development and management components
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