348 research outputs found
AN EVALUATION OF GOOGLE STREET VIEW AS AN ENVIRONMENTAL DATA SOURCE FOR CONDUCTING PARK AUDITS
INTRODUCTION In Canada, physical inactivity is responsible for an estimated $6.8 billion of direct and indirect health care costs. Many adults do not accrue the levels of physical activity necessary to ensure optimal health benefits. Growing evidence suggests that the built environment, including convenient access to high quality public open space, has the potential to influence physical activity. Google Street View (GSV) has been shown to be a feasible data source for auditing community walkability and recreational facilities; however, few studies have taken advantage of GSV to audit public open space and park specific features that can influence physical activity. This study evaluates the feasibility, reliability, and validity of conducting virtual park audits using environmental park attribute data sourced from GSV.  METHODS Parks (n=34) were purposively sampled from 11 neighbourhoods with differing socioeconomic status (low, low-medium, high- medium, and high) and urban form (grid, warped-grid, and curvilinear street patterns). The Public Open Space Tool (POST; adapted to the Canadian context) was used to measure the quality of each park in terms of supporting physical activity behaviour. Two raters systematically audited parks using the POST via GSV and Google Maps aerial image at two time points (ten days between each audit round). Raters’ combined GSV audit data was compared at time one and time two using Kappa coefficients, intraclass correlations (ICC) and percent of overall agreement (POA) to evaluate intra-rater reliability. Inter-rater reliability was determined by comparing the raters’ time two GSV audit data.  RESULTS Intra-rater reliability for all POST items using GSV audits were poor to excellent (POA = 70.6-100% and kappa/ICC = 0.32-1.00). Inter-rater reliability for POST items also ranged from poor to excellent (POA = 52.9-100% and kappa/ICC = 0.10-1.00). Concurrent validity of GSV compared with aerial image audits also ranged from poor to excellent (POA = 63-100% and kappa/ ICC = 0.12-1.00). GSV audits took an average of 13±4 minutes, while aerial image audits took 7±2 minutes, to complete.  CONCLUSIONS GSV is a potentially reliable and valid method for conducting park audits. Most POST items had good to excellent intra- and inter-rater agreement, as well as adequate concurrent validity with the aerial image audits. GSV audit times in this study were comparable to those found elsewhere. Findings suggest that conducting virtual park audits with the POST using GSV data is a feasible, reliable, and valid approach.
Virtual slit scanning microscopy
We present a novel slit scanning confocal microscope with a CCD camera image sensor and a virtual slit aperture for descanning that can be adjusted during post-processing. A very efficient data structure and mathematical criteria for aligning the virtual aperture guarantee the ease of use. We further introduce a method to reduce the anisotropic lateral resolution of slit scanning microscopes. System performance is evaluated against a spinning disk confocal microscope on identical specimens. The virtual slit scanning microscope works as the spinning disk type and outperforms on thick specimen
Widefield fluorescence microscopy with extended resolution
Widefield fluorescence microscopy is seeing dramatic improvements in resolution, reaching today 100nm in all three dimensions. This gain in resolution is achieved by dispensing with uniform Köhler illumination. Instead, non-uniform excitation light patterns with sinusoidal intensity variations in one, two, or three dimensions are applied combined with powerful image reconstruction techniques. Taking advantage of non-linear fluorophore response to the excitation field, the resolution can be further improved down to several 10nm. In this review article, we describe the image formation in the microscope and computational reconstruction of the high-resolution dataset when exciting the specimen with a harmonic light pattern conveniently generated by interfering laser beams forming standing waves. We will also discuss extensions to total internal reflection microscopy, non-linear microscopy, and three-dimensional imagin
Dimensional reduction by pressure in the magnetic framework material CuF(DO)pyz: from spin-wave to spinon excitations
Metal organic magnets have enormous potential to host a variety of electronic
and magnetic phases that originate from a strong interplay between the spin,
orbital and lattice degrees of freedom. We control this interplay in the
quantum magnet CuF(DO)pyz by using high pressure to drive the
system through a structural and magnetic phase transition. Using neutron
scattering, we show that the low pressure state, which hosts a two-dimensional
square lattice with spin-wave excitations and a dominant exchange coupling of
0.89 meV, transforms at high pressure into a one-dimensional spin-chain
hallmarked by a spinon continuum and a reduced exchange interaction of 0.43
meV. This direct microscopic observation of a magnetic dimensional crossover as
a function of pressure opens up new possibilities for studying the evolution of
fractionalised excitations in low dimensional quantum magnets and eventually
pressure-controlled metal--insulator transitions
Direct transcriptional repression of the genes encoding the zinc-finger proteins Gfi1b and Gfi1 by Gfi1b
Gfi1b is a 37 kDa transcriptional repressor with six zinc-finger domains that is differentially expressed during hemato- and lymphopoiesis. We show here that transcription from the Gfi1b gene locus is silenced in the spleen but not in the bone marrow of transgenic mice that constitutively express Gfi1b under the control of the pan-hematopoietic vav promoter. Sequence analysis of the Gfi1b promoter showed the presence of potential Gfi1/Gfi1b-binding sites close to the mRNA start site. The expression of reporter gene constructs containing the Gfi1b core promoter appended to the luciferase gene were strongly repressed in the presence of exogenous Gfi1b. Moreover, analysis of combinatorial mutant mice that carry the vav-Gfi1b transgene and a green fluorescent protein-tagged Gfi1 gene locus demonstrated that the Gfi1 gene can be repressed by Gfi1b. Direct binding of Gfi1b and Gfi1 to the potential binding sites in the Gfi1b promoter could be demonstrated by gel-shift analyses in vitro. Chromatin-immunoprecipitation experiments showed that both the Gfi1b and the Gfi1 promoter are indeed occupied by Gfi1b in vivo. Hence, we conclude from our data that Gfi1b can auto-repress its own expression, but, in addition, is also able to cross-repress expression of the Gfi1 gene most likely in a cell type specific manner
Generierung zweier knock in Mausmutanten zur funktionellen Charakterisierung einzelner Domänen des Gfi1-Zinkfingerproteins
Gfi1 ist ein Zinkfinger-Transkriptionsfaktor, der eine wichtige Rolle in der Hämatopoese und der Innenohr-Entwicklung spielt. Mäuse, die defizient für Gfi1 sind, weisen eine starke Neutropenie, Defekte in der T-Lymphozytenentwicklung und in der Differenzierung der Haarzellen des Innenohrs auf. Eng mit Gfi1 verwandt ist das Gfi1b Zinkfinger-Protein; beide sind strukturell stark homolog, weisen jedoch unterschiedliche Expressionsmuster und knock out Phänotypen auf. Um die funktionelle Homologie von Gfi1 und Gfi1b näher untersuchen zu können, wurde die Gfi1-Genregion in der Maus durch die für Gfi1b codierende Sequenz ersetzt, wodurch eine Expression von Gfi1b unter Gfi1 spezifischen Kontroll-Elementen erreicht wurde.
Die durchgeführten Untersuchungen dieser Gfi1:Gfi1b knock in Mäuse zeigten, dass beide Proteine eine weitreichende funktionelle Homologie im hämatopoetischen System aufweisen: Durch die Gfi1b-Expression in Gfi1 defizienten Mäusen wird die Neutropenie aufgehoben und die Defekte in der T-Lymphozytenentwicklung werden abgeschwächt. Bei der Analyse der Innenohr-Haarzellen zeigte sich, dass diese funktionelle Homologie zelltypspezifisch ist: In sensorischen Zellen konnten die Defekte der Gfi1 Verlustmutante nicht durch die Gfi1b-Expression aufgehoben werden. Gfi1:Gfi1b knock in Mäuse weisen degradierte Haarzellen auf und sind taub.
Die Tatsache, dass Gfi1 reprimierend auf seine Zielgene wirkt, legt nahe, dass ein Verlust der repressorischen Wirkung des Proteins starke Auswirkungen auf dessen Funktion hat. In vitro war in früheren Studien die repressorische Wirkung von Gfi1 durch eine Punktmutation in der SNAG-Domäne aufgehoben worden. Um die Folgen des Verlustes der Repression in vivo untersuchen zu können, wurde in einem zweiten Mausmodell die zuvor beschriebene Punktmutation in das Gfi1-Gen eingeführt und der Phänotyp dieser Mäuse analysiert. Es zeigte sich, dass die repressorische Wirkung des Gfi1-Proteins für alle in dieser Arbeit untersuchten Funktionen unverzichtbar ist: Die Tiere waren, obwohl sie Gfi1 – in einer mutierten Form – exprimierten, nicht von den Gfi1 defizienten Mäusen unterscheidbar
A Vision of Digitalization in Supply Chain Management and Logistics
Digitalization requires a new form of management to master the transformation process of corporations and companies. The Dortmund Management Model structures the focus areas of the digital transformation along the management tasks goal, planning, decision, realization and monitoring as well as the common socio-technical subsystems technological, organizational and personnel - enriched by a fourth dimension: information. Additionally, the acceleration factors transformation, migration and change management are taken into account.
This paper embraces a vision for a persistent management of production and supply chain networks in order to achieve a holistic Management 4.0. The emerging developments of technology, methods, tools and models in production and supply chain research are connected and merged into a big picture of digital supply chain management and logistics. The interfaces between management tasks show specific characteristics of digital business processes in particular, which are hereinafter exemplarily outlined:
New business models and value-creation networks are based on adaption intelligent production systems, which are interconnected with digital models for continuous planning and reconfiguration. At the shop floor and between sites orders are completed by autonomous guided vehicles (AGV) with intelligent load carriers. Decentralized negotiations and decisions across company boundaries concluded with smart contracts are enabling reasonable and sustainable distribution of the value creation processes. Humans are still in the center of action – abilities are developed by integrated competence management, new learning approaches and human-centered assistance systems coupled with AI-based decision-making support. New types of organizations allow a synergetic collaboration of humans and machines. The benefit of integrating new production and transport technologies becomes assessable and accelerates the ongoing renewal of existing networks.
This paper provides an overview of possible potential and connecting factors by linking different technological developments towards supply chain, logistics, production and management research and shows further research demands
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