12,682 research outputs found
Alignment of the atmospheric visibility monitoring telescope
Alignment of the first Atmospheric Visibility Monitoring Telescope has revealed errors in mount design, mount manufacture, software, and electronics. This article discusses error sources and solutions, and re-alignment results. Alignment requirements for operation are also presented. The telescope now operates with the desired accuracy and repeatability
Options for daytime monitoring of atmospheric visibility in optical communications
Techniques for daytime detection of atmospheric transmission and cloud cover to determine the capabilities of future deep-space optical communications links are considered. A modification of the planned nighttime photometry program will provide the best data while minimizing the need for further equipment. Greater degrees of modification will provide increased detection capabilities. Future testing of the equipment will better define the improvement offered by each level of modification. Daytime photometry is favored at certain wavelengths because of higher transmission and lower background noise, thus giving an increased signal-to-noise ratio. A literature search has provided a list of stars brighter than second magnitude at these wavelengths
Economic and Organizational Issues in Alaska Water Quality Management
The work upon which this report (Proj. A-029-ALAS) is based was supported by funds provided
by the United States Department of the Interior, Office of Water Resources Research, as
authorized under the Water Resources Act of 1964
A qualitative analysis of the factors that protect athletes against doping in sport
Design: Ten competitive athletes (M = 5, F = 5) representing five different sports (field hockey, boxing, football, triathlon, rugby) were recruited through convenience sampling to undertake a semi-structured interview to enable a qualitative analysis of athletes' lifelong athletic careers. Method: Verbatim transcripts were analysed using an established three-stage coding process to identify the common themes within the narratives. Results: Personal and situational protective factors were identified in the accounts. Personal factors included: (i) a strong moral stance against cheating; (ii) an identity beyond sport; (iii) self-control; and (iv) resilience to social group pressures. Situational factors included secure attachments to people at all stages of the athlete's life. This facilitated both the promotion of moral decision making and assisted in the development of anti-doping attitudes. When situational factors – such as a pro-doping climate – arose, key attachments in the athletes' lives interplayed with personal factors to reduce the risk of doping. Conclusions: These findings offer insights into factors that protect competitive athletes against using PEDs in sport and further our understanding of the complex interaction between risk and protective factors at individual, psychosocial and societal levels among competitive athletes. As a complex behaviour, doping in sport cannot be prevented by solely focussing on the individual athlete; contextual factors beyond the athlete's control also impact on this behaviour. Thus, a paradigm shift is warranted to move beyond an athlete-centred approach to anti-doping
Plasma heating, plasma flow and wave production around an electron beam injected into the ionosphere
A brief historical summary of the Minnesota ECHO series and other relevant electron beam experiments is given. The primary purpose of the ECHO experiments is the use of conjugate echoes as probes of the magnetosphere, but beam-plasma and wave studies were also made. The measurement of quasi-dc electric fields and ion streaming during the ECHO 6 experiment has given a pattern for the plasma flow in the hot plasma region extending to 60m radius about the ECHO 6 electron beam. The sheath and potential well caused by ion orbits is discussed with the aid of a model which fits the observations. ELF wave production in the plasma sheath around the beam is briefly discussed. The new ECHO 7 mission to be launched from the Poker Flat range in November 1987 is described
A rapid method for the computation of equilibrium chemical composition of air to 15000 K
A rapid computational method has been developed to determine the chemical composition of equilibrium air to 15000 K. Eleven chemically reacting species, i.e., O2, N2, O, NO, N, NO+, e-, N+, O+, Ar, and Ar+ are included. The method involves combining algebraically seven nonlinear equilibrium equations and four linear elemental mass balance and charge neutrality equations. Computational speeds for determining the equilibrium chemical composition are significantly faster than the often used free energy minimization procedure. Data are also included from which the thermodynamic properties of air can be computed. A listing of the computer program together with a set of sample results are included
User Illusion: ideological construction of ‘user-generated content’ in the EC consultation on copyright
Recent policy consultations by the UK Intellectual Property Office, the US Patent and Trademark Office and the European Commission (EC) have highlighted the importance of user-generated content in debates to reform copyright. User-generated content (UGC) – often combining existing copyright material with transformative creativity – remains a contested terrain, with no clear or widely accepted definition. This paper examines how various stakeholders in the 2014 EC consultation on copyright attempted to shape the definition of UGC in order to suit their interests, sometimes aligning or conflicting with other stakeholder groups. Data from 203 written responses by registered stakeholders (authors, platform intermediaries and users) were subjected to a discourse analysis methodology. Key arguments and policy preferences from each stakeholder group are identified and discussed
Defining the public domain in economic terms: Approaches and consequences for policy
Stimulating innovation and growth in the so-called ‘creative economy’ is a current policy objective for national regulators. One policy lever traditionally applied to the creative sector is intellectual property, in particular the scope and term of protection offered by copyright. Opposition to expansion and further enclosure of the copyright public domain was previously articulated in terms of access to a commons of information. Since the Hargreaves Review of Intellectual Property in 2011, copyright reform in the UK context is increasingly framed in the language of economics. This paper reviews two prevailing economic theories shaping how policy makers discuss the public domain in debates about IP reform: a welfare economics approach which weighs increases in producer and consumer surplus under different policy configurations and an economics of innovation approach which considers the value of the public domain as a reservoir of ideas for individuals and firms. I argue that economic definitions should be augmented by a consideration of the democratic requirement of access to information. The consequences of this re-figuration of the public domain for the public interest and access to information are discussed
Transient expression in Nicotiana benthamiana for rapid functional analysis of genes involved in non-photochemical quenching and carotenoid biosynthesis.
Plants must switch rapidly between light harvesting and photoprotection in response to environmental fluctuations in light intensity. This switch can lead to losses in absorbed energy usage, as photoprotective energy dissipation mechanisms can take minutes to hours to fully relax. One possible way to improve photosynthesis is to engineer these energy dissipation mechanisms (measured as non-photochemical quenching of chlorophyll a fluorescence, NPQ) to induce and relax more quickly, resulting in smaller losses under dynamic light conditions. Previous studies aimed at understanding the enzymes involved in the regulation of NPQ have relied primarily on labor-intensive and time-consuming generation of stable transgenic lines and mutant populations - approaches limited to organisms amenable to genetic manipulation and mapping. To enable rapid functional testing of NPQ-related genes from diverse organisms, we performed Agrobacterium tumefaciens-mediated transient expression assays in Nicotiana benthamiana to test if NPQ kinetics could be modified in fully expanded leaves. By expressing Arabidopsis thaliana genes known to be involved in NPQ, we confirmed the viability of this method for studying dynamic photosynthetic processes. Subsequently, we used naturally occurring variation in photosystem II subunit S, a modulator of NPQ in plants, to explore how differences in amino acid sequence affect NPQ capacity and kinetics. Finally, we functionally characterized four predicted carotenoid biosynthesis genes from the marine algae Nannochloropsis oceanica and Thalassiosira pseudonana and examined the effect of their expression on NPQ in N. benthamiana. This method offers a powerful alternative to traditional gene characterization methods by providing a fast and easy platform for assessing gene function in planta
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