16,175 research outputs found
Ka-band (32 GHz) spacecraft development plan
A road map for the development of a protoflight 32 GHz spacecraft solid state transmitter is given. The major milestones include the development of device and component technology required for use in the spaceborne experimental and operational transmitter systems. Two experimental spacecraft transmitter systems are envisioned: first, a low power beacon, to determine the performance of a 32 GHz downlink communications system; and second, an array feed, to further verify the results of the first experiment and service as a test bed for technology required for an operational system. The first experiment was proposed to NASA Headquarters for flight aboard the Mars Observer spacecraft with spacecraft integration in early 1989. The second is to be available for integration aboard a spacecraft such as the Comet Rendezvous Asteroid Flyby (CRAF) mission in the 1990 time frame. These experimental systems are to lead to the development of a protoflight transmitter for subsequent spacecraft integration in 1992, the time frame of the Cassini mission to Saturn
Photoelectric observations of Mars and Jupiter with a scanning polarimeter
Photoelectric observations of Mars and Jupiter with scanning polarimete
A pitfall of piecewise-polytropic equation of state inference
The only messenger radiation in the Universe which one can use to
statistically probe the Equation of State (EOS) of cold dense matter is that
originating from the near-field vicinities of compact stars. Constraining
gravitational masses and equatorial radii of rotating compact stars is a major
goal for current and future telescope missions, with a primary purpose of
constraining the EOS. From a Bayesian perspective it is necessary to carefully
discuss prior definition; in this context a complicating issue is that in
practice there exist pathologies in the general relativistic mapping between
spaces of local (interior source matter) and global (exterior spacetime)
parameters. In a companion paper, these issues were raised on a theoretical
basis. In this study we reproduce a probability transformation procedure from
the literature in order to map a joint posterior distribution of Schwarzschild
gravitational masses and radii into a joint posterior distribution of EOS
parameters. We demonstrate computationally that EOS parameter inferences are
sensitive to the choice to define a prior on a joint space of these masses and
radii, instead of on a joint space interior source matter parameters. We focus
on the piecewise-polytropic EOS model, which is currently standard in the field
of astrophysical dense matter study. We discuss the implications of this issue
for the field.Comment: 16 pages, 9 figures. Accepted for publication in MNRA
High voltage solid-state relay
Hybrid microelectronics relay has characteristics significantly superior to conventional solid state relays. Relay provides 2500 Vdc input to output isolation and operates from high threshold logic signal to switch load of 400 Vdc at 2 mA. Technology should be of interest to manufacturers of discrete components
Air quality indices from ERTS-1 MSS information
Comparison between ground based atmospheric turbidity network measurements and the average scene grayness from MSS Channel 4 data is in progress. Correlation between these two sources is promising. If continued correlation occurs for other ERTS-1 overflight dates and ground test sites, a new operational use of ERTS-1 useful to Federal, state, and international organizations will become available
Ka-band MMIC beam steered transmitter array
A 32-GHz six-element linear transmitter array utilizing monolithic microwave integrated circuit (MMIC) phase shifters and power amplifiers was designed and tested as part of the development of a spacecraft array feed for NASA deep-space communications applications. Measurements of the performance of individual phase shifters, power amplifiers, and microstrip radiators were carried out, and electronic beam steering of the linear array was demonstrated. The switched-line phase shifters were accurate to within 7 percent on average and the power amplifier 1-dB compressed output power varied over 0.3 dB. The array had a beamwidth of 7.5 deg and demonstrated acceptable beam steering over + or - 8 deg. From the results, it can be concluded that this MMIC phased array has adequate beam-scanning capability for use in the two-dimensional array. The areas that need to be improved are the efficiency of the MMIC power amplifier and the insertion loss of the MMIC phase shifter
A Ka-band (32 GHz) beacon link experiment (KABLE) with Mars Observer
A proposal for a Ka-Band (32 GHz) Link Experiment (KABLE) with the Mars Observer mission was submitted to NASA. The experiment will rely on the fourth harmonic of the spacecraft X-band transmitter to generate a 33.6 GHz signal. The experiment will rely also on the Deep Space Network (DSN) receiving station equipped to simultaneously receive X- and Ka-band signals. The experiment will accurately measure the spacecraft-to-Earth telecommunication link performance at Ka-band and X-band (8.4 GHz)
Aims for service user involvement in mental health training: staying human
Purpose: Studies have examined the impact of service user involvement in mental health training but little is known about what staff, trainees and service users themselves want to achieve.
Methodology: Three separate focus groups were held with service users, training staff and trainees associated with a clinical psychology training programme. Thematic analysis was used to identify aims for involvement.
Findings: All groups wanted to ensure that future professionals “remained human” in the way they relate to people who use services. Service user and carer involvement was seen as a way of achieving this and mitigating the problem of “them and us thinking”. We found that groups had some aims in common and others that were unique. Service users highlighted the aim of achieving equality with mental health professionals as an outcome of their involvement in teaching.
Research limitations: The samples were small and from one programme.
Practical implications: Common aims can be highlighted to foster collaborative working. However, the findings suggest that service users and carers, staff and trainees may also have different priorities for learning. These need to be recognised and addressed by mental health educators.
Originality/value: This was the first study to explore in depth the differing aims of different stakeholder groups for service user involvement. Clarification of aims is a vital first step in developing any future measure of the impact of service user involvement on mental health practice
Inclusivity on Campus: Strategies for Counselors Creating Community for All Students with an Emphasis on Muslim College Students
Recent statistics suggest that the current campus climate across the United States does not fully support inclusivity of students of marginalized groups, as one aspect of student wellness. In this manuscript, the authors review current literature on the experiences of marginalized student groups, focusing on injustices experienced by Muslim students on today’s campuses. The authors acknowledge the current collaborate efforts that many college counselors are putting forth to promote a more inclusive campus environment, while also recognizing that marginalization of students is still present on campuses nationwide. Further, the manuscript will address concerns with student wellness in the Muslim student population by highlighting the impact inclusion has on holistic student wellness. In summary, the authors outline opportunities for college counselors to notice the negative impact of injustice on student wellbeing, engage in collaboration focused on creating inclusivity campus-wide, provide diversity education for their campuses, and reflect on their own personal and professional experiences
The Regulation of Aggrecanase ADAMTS-4 Expression in Human Achilles Tendon and tendon-Derived Cells
Several members of the ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) family have been identified as aggrecanases, whose substrates include versican, the principal large proteoglycan in the tendon extracellular matrix. We have characterized the expression of ADAMTS-4 in human Achilles tendon and tendon-derived cells. ADAMTS-4 mRNA levels were higher in ruptured tendon compared with normal tendon or chronic painful tendinopathy. In tissue extracts probed by Western blotting, mature ADAMTS-4 (68 kDa) was detected only in ruptured tendons, while processed ADAMTS-4 (53 kDa) was detected also in chronic painful tendinopathy and in normal tendon. In cultured Achilles tendon cells, transforming growth factor-ß (TGF-ß) stimulated ADAMTS-4 mRNA expression (typically 20-fold after 24 h), while interleukin-1 induced a smaller, shorter-term stimulation which synergised markedly with that induced by TGF-ß. Increased levels of immunoreactive proteins consistent with mature and processed forms of ADAMTS-4 were detected in TGF-ß-stimulated cells. ADAMTS-4 mRNA was expressed at higher levels by tendon cells in collagen gels than in monolayer cultures. In contrast, the expression of ADAMTS-1 and -5 mRNA was lower in collagen gels compared with monolayers, and these mRNA showed smaller or opposite responses to growth factors and cytokines compared with that of ADAMTS-4 mRNA. We conclude that both ADAMTS-4 mRNA and ADAMTS-4 protein processing may be differentially regulated in normal and damaged tendons and that both the matrix environment and growth factors such as TGF-ß are potentially important factors controlling ADAMTS aggrecanase activities in tendon pathology
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