Complementary satellite sound broadcasting systems: A NASA assessment for the Voice of America

Satellite concepts are examined which offer potentially significant sound broadcast coverage of audio as a complement to VOA's existing and planned terrestrial sound broadcasting system. HF bands are emphasized but additional discussion is included for systems using higher frequencies. Low altitude satellites, shuttle altitude (275 km) and sun synchronous (about 1600 to 1800 km), would not be practical for international broadcasting since many satellites would be required for reliable and widespread coverage. Two concepts are discussed which would offer significant and practical broadcast coverage at HF. One, an 8-hr posigrade equatorial orbit, would offer about 1 hr of widespread, twice daily, coverage to three areas of the globe. The time of coverage is even greater when confined to densely populated areas only (2 to 3 hrs). Another orbit, the Apogee at Constant Time/Equatorial (ACE), provides the same coverage, but only once daily to each area. The latter orbit is highly elliptical, allowing insertion of a greater payload (more broadcast channels) with the existing launch capability. The ACE and 8-hr orbit concepts led to systems of about equal costs, with the ACE being slightly better

ULF waves in the solar wind as direct drivers of magnetospheric pulsations

[1] Global magnetospheric ULF pulsations with frequencies in the Pc 5 range (f = 1.7–6.7 mHz) and below have been observed for decades in space and on the Earth. Recent work has shown that in some cases these pulsations appear at discrete frequencies. Global cavity and waveguide modes have been offered as possible sources of such waves. In these models the magnetosphere is presumed to resonate globally at frequencies determined solely by its internal properties such as size, shape, field topology, mass density distribution, etc. We show in this work that upstream solar wind number density and dynamic pressure variations precede and drive compressional magnetic field variations at geosynchronous orbit. Furthermore, spectral analysis shows that wave power spectra in both the solar wind and magnetosphere contain peaks at the same discrete frequencies. Therefore, in contrast to the cavity mode hypothesis, we suggest that discrete ULF pulsations observed within the magnetosphere are at least sometimes directly driven by density oscillations present in the ambient solar wind. Finally, we comment on possible sources for such pulsations observed in the solar wind

Plato's Ring of Corruption.

Although corruption has been widely reported and is easily recognized, often unfortunately after the event, its nature and causes are usually not well understood and remain for the most part conceptually unclear. This conceptual lack of clarity concerning the nature of corruption helps perpetuate its reign. In order to provide a better conceptual and ethical understanding of corruption, I have developed a philosophical model that seeks to conceptually identify, explain and ethically evaluate corruption through first identifying and defining its characterizing features. To that end, the paper will provide a philosophical account of contemporary corruption by determining, through an analysis of the Myth of Gyges in Plato’s Republic, the essential features that characterize corporate and other types of corruption. The analysis will adopt an applied philosophical approach, one that will attempt to reveal the significance and relevance of Plato’s Myth of Gyges for an applied philosophical understanding of contemporary corruption

Philosophy Plays: A Neo-Socratic Way of Performing Public Philosophy

This paper provides an explanatory rationale within a theoretical framework for the Philosophy Plays project. The object of the Philosophy Plays is to introduce philosophy, and especially Western Philosophy, to the general public through philosophical presentations by professional philosophers incorporating drama. They have created a public domain for philosophy where relevant issues and topics of public interest and importance, such as love, immortality, happiness, friendship, religion, knowledge, trust, pets, morality and corruption, can be presented by professional philosophers and discussed in an open forum with members of the general public. The Philosophy Plays, like Platonic dialogues, seek to engage their audiences both intellectually (primarily through the philosophical talk) and emotionally (primarily through the drama). So like Plato’s dialogues, from which they draw their inspiration, the Philosophy Plays which combine dialectic (the philosophical talk) with rhetoric (the drama) seek to engage their public audiences in a realistic and shared lived experience thus rendering philosophy a practical and meaningful activity for all participants

REGROWTH OF CHLORELLA SOROKINIANA ON RECYCLED MEDIA WITH REPLENISHED NUTRIENTS

Growth media recycling during algae cultivation is necessary to increase the efficiency and reduce the cost of biofuel production from algae feedstocks. Without recycling media, the cost of algae based biofuel production would be prohibitively high and large scale algae based biofuel production would not be economically viable. The ratio of media recycled to media wasted assumed for algae farms is generally calculated to maintain salt concentrations below growth inhibitory levels, ignoring the influence of secondary metabolites which might decrease productivity. Secondary metabolites, which include allelopathic or auto-inhibitory biological contaminants, might lead to the accumulation of growth-inhibiting compounds in recycled media used in algae production. Chlorella sorokiniana (strain DOE1412) was a leading algae biofuel feedstock candidate and has not previously been evaluated for inhibitor production. To test the effects of water recycling on the growth of DOE1412, media was recycled through multiple rounds of algae cultivation. DOE1412 was grown in modified BG11 culture media until reaching the end of linear growth phase, at which point the biomass was removed, nutrients replenished to their initial concentrations, and the recycled culture media used for a subsequent round of growth. The culture media was recycled through five rounds of growth with cultures grown on recycled media compared to controls grown on freshly prepared growth media. Biomass density was monitored via optical density and the specific and productivity growth rates were used to quantify the extent of inhibition. Exploratory work was performed with the goal of identifying potential inhibitory substances produced by DOE1412 during cultivation. Samples of recycled media were analyzed for polyunsaturated fatty acids which have been demonstrated to be inhibitory. The carbohydrates content of used media was analyzed to assess the amount of organic materials shed by DOE1412 into recycled media during growth. The log phase growth rate (day-1) of DOE1412 was inhibited by 3±2%, 8±1%, 10±2%, and 18.6±0.9% when grown in media recycled 1-4 times, respectively, with a 99% level of confidence that inhibition was observed in each round of regrowth. The productivity growth rate (OD750/day) of DOE1412 was not inhibited in media recycled 1-3 times. The productivity growth rate of DOE1412 was inhibited by 13±3% when grown in media recycled 4 times with a 99% level of confidence that inhibition was observed. Zinc was found to accumulate in the recycled media to potentially toxic levels (\u3e0.09 mg/L), therefore it is uncertain if the observed inhibition was due to an accumulation of inhibitory secondary metabolites or the accumulation of zinc. Two inhibitory polyunsaturated acids, linoleic and linolenic acid, were identified in media recycled 4 times. The carbohydrate content of recycled media fluctuated between 8-10% of total fixed carbon in media recycled 1-3 times and increased to 18% in media recycled 4 times. However, changes observed in media recycled 4 times may have been due to improper storage of used media

Using stepped-care approaches within internet-based interventions for youth anxiety: Three case studies.

Background There are a lack of clear guidelines for the dissemination of Internet-based cognitive behaviour therapy (ICBT) for childhood and adolescent anxiety in routine care. While self-guided ICBT has greater reach than therapist-guided ICBT, it is plagued by problems of low program adherence and many young people are not successfully treated. It is important that we identify models of ICBT that are accessible, but provide the right support, at the right time to those who need it. Stepped-care models of ICBT offer one potential solution. Objective This case study examined the application of stepped-care within an ICBT intervention for childhood and adolescent anxiety, in which young people were stepped up from self-guided to therapist-guided ICBT. Methods Three case studies are presented and include young males (aged 11–12 years) who participated in BRAVE Stepped-Care, a new ICBT program incorporating two treatment steps: Step 1 – five sessions of self-guided ICBT and Step 2 – five sessions of therapist-guided ICBT. Participants completed diagnostic assessments at pre- and post-treatment, along with a battery of self-report questionnaires. Step-up requirements were determined at a mid-treatment assessment. Treatment response was determined by change on diagnostic severity and presence of diagnosis and changes in self-reported anxiety symptoms (through T-scores and Reliable Change Indices). Results In-depth examination of the three case studies showed that decisions to step-up from Step 1 to Step 2 were complex and required consideration of program engagement and adherence, as well as changes on self-reported anxiety, behavioural indicators of anxiety and parent perspectives. Results showed that non-responders at mid-treatment who were stepped-up to therapist-guided ICBT after Step 1 were able to increase engagement and response to treatment in Step 2, such that they were free of their primary anxiety diagnosis at post-treatment. Conclusions The findings highlight the importance of early assessment of engagement and non-response within self-guided ICBT programs for youth anxiety and the positive changes that can subsequently occur when therapist-guidance is introduced mid-treatment for non-responders. The efficacy of stepped-care ICBT models needs to be confirmed in larger randomised controlled trials

A statistical study of the global structure of the ring current

[1] In this paper we derive the average configuration of the ring current as a function of the state of the magnetosphere as indicated by the Dst index. We sort magnetic field data from the Combined Release and Radiation Effects Satellite (CRRES) by spatial location and by the Dst index in order to produce magnetic field maps. From these maps we calculate local current systems by taking the curl of the magnetic field. We find both the westward (outer) and the eastward (inner) components of the ring current. We find that the ring current intensity varies linearly with Dst as expected and that the ring current is asymmetric for all Dst values. The azimuthal peak of the ring current is located in the afternoon sector for quiet conditions and near midnight for disturbed conditions. The ring current also moves closer to the Earth during disturbed conditions. We attempt to recreate the Dst index by integrating the magnetic perturbations caused by the ring current. We find that we need to multiply our computed disturbance by a factor of 1.88 ± 0.27 and add an offset of 3.84 ± 4.33 nT in order to get optimal agreement with Dst. When taking into account a tail current contribution of roughly 25%, this agrees well with our expectation of a factor of 1.3 to 1.5 based on a partially conducting Earth. The offset that we have to add does not agree well with an expected offset of approximately 20 nT based on solar wind pressure