2,116 research outputs found
Frequency and timing system for the consolidated DSN and STDN tracking network
The consolidation on the existing Deep Space Network (DSN) and colocated Goddard Spaceflight Tracking and Data Network (STDN) stations into a multiple antenna array is discussed. Each site includes a signal processing center (SPC) centered in an array of four or five antennas each located within approximately 300 to 800 meters of the SPC. A central frequency and timing system (FTS) located in the SPC contains reference frequency, timing and time code generation, and distribution equipment for both the SPC and each antenna with its associated front end antenna control building. The reference frequency distribution and clock equipment are driven by a hydrogen maser as the prime frequency standard with cesium beam frequency standard as the secondary
Unlike particle correlations and the strange quark matter distillation process
We present a new technique for observing the strange quark matter
distillation process based on unlike particle correlations. A simulation is
presented based on the scenario of a two-phase thermodynamical evolution model.Comment: 15 pages, 2 figures, 1 tabl
The fast and furious
Cocaine and amphetamines (‘stimulants’) are distinct central nervous system stimulants with similar effects (Pleuvry, 2009; Holman, 1994). Cocaine is a crystalline tropane alkaloid extracted from coca leaves. Amphetamines are a subclass of phenylethylamines with primarily stimulant effects, including amphetamine, methamphetamine, methcathinone and cathinone and referred to as ‘amphetamines’ in this review (Holman, 1994). MDMA (3,4-methylenedioxy-N-methamphetamine or ecstasy) is a substituted amphetamine known for its entactogenic, psychedelic, and stimulant effects (Morgan, 2000). Stimulants can produce increased wakefulness, focus and confidence, elevated mood, feelings of power, and decreased fatigue and appetite; stimulants also produce nervousness or anxiety and, in some cases, psychosis and suicidal thoughts (Holman, 1994; EMCDDA, 2007f; Hildrey et al., 2009; Pates and Riley, 2009). Although there is little evidence that stimulants cause physical dependence, tolerance may develop upon repetitive use and withdrawal may cause discomfort and depression (EMCDDA, 2007f; Pates and Riley, 2009). Users may engage in ‘coke or speed binges’ alternated with periods of withdrawal and abstinence (Beek et al., 2001)
Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic
Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic (March 25 - 27, 2018 -- The University of New Hampshire) paired two of NSF\u27s 10 Big Ideas: Navigating the New Arctic and Growing Convergence Research at NSF. During this event, participants assessed economic, environmental, and social impacts of Arctic change on New England and established convergence research initiatives to prepare for, adapt to, and respond to these effects. Shipping routes through an ice-free Northwest Passage in combination with modifications to ocean circulation and regional climate patterns linked to Arctic ice melt will affect trade, fisheries, tourism, coastal ecology, air and water quality, animal migration, and demographics not only in the Arctic but also in lower latitude coastal regions such as New England. With profound changes on the horizon, this is a critical opportunity for New England to prepare for uncertain yet inevitable economic and environmental impacts of Arctic change
Radio Occultation Measurements of Europa's Ionosphere From Juno's Close Flyby
On 29 September 2022 the Juno spacecraft flew within 354 km of Europa's surface while several instruments probed the moon's surroundings. During the close flyby, radio occultations were performed by collecting single-frequency Doppler measurements. These investigations are essential to the study of Europa's ionosphere and represent the first repeat sampling of any set of conditions since the Galileo era. Ingress measurements resulted in a marginal detection with a peak ionospheric density of 4,000 ± 3,700 cm−3 (3σ) at 22 km altitude. A more significant detection emerged on egress, with a peak density of 6,000 ± 3,000 cm−3 (3σ) at 320 km altitude. Comparison with Galileo measurements reveals a consistent picture of Europa's ionosphere, and confirms its dependence on illumination conditions and position within Jupiter's magnetosphere. However, the overall lower densities measured by Juno suggest a dependence on time of observation, with implications for the structure of the neutral atmosphere
Laying the foundations of community engagement in Aboriginal health research: establishing a community reference group and terms of reference in a novel research field
Background
Community engagement or community involvement in Aboriginal health research is a process that involves partnering, collaborating and involving Aboriginal and Torres Strait Islander people or potential research participants to empower them to have a say in how research with Aboriginal communities is conducted. In the context of Aboriginal health, this is particularly important so that researchers can respond to the priorities of the community under study and conduct research in a way that is respectful of Aboriginal cultural values and beliefs. One approach to incorporating the principals of community engagement and to ensure cultural oversight and guidance to projects is to engage a community reference group. The aim of this study was to describe the process of establishing an Aboriginal community reference group and terms of reference. The community reference group was established to guide the research activities of a newly formed research collaboration aiming to to develop osteoarthritis care that meets the needs of Aboriginal and Torres Strait Islander people in Australia.
Methods
Adopting a Participatory Action Research approach, this two-phase study was conducted in Victoria, Australia. In phase one, semi-structured research yarns (a cultural form of conversation used as a data gathering tool) were conducted collaboratively by Aboriginal and non-Aboriginal co-investigators to explore Aboriginal health stakeholder perspectives on establishing a community reference group and terms of reference. In phase two, recommendations in phase one were identified to invite members to participate in the community reference group and to ratify the terms of reference through a focus group. Data were analyzed using a framework analysis approach.
Results
Thirteen people (eight female, four male) participated in phase one. Participants represented diverse professional backgrounds including physiotherapy, nursing, general practice, health services management, hospital liaison, cultural safety education, health research and the arts. Three themes were identified in phase one; Recruitment and Representation (trust and relationships, in-house call-outs, broad-spectrum expertise and Aboriginal majority); Purpose (community engagement, research steering, knowledge dissemination and advocacy) and; Function and Logistics (frequency and format of meetings, size of group, roles and responsibilities, authority, communication and dissemination). In phase two, six Aboriginal people were invited to become members of the community reference group who recommended changes which were incorporated into the seven domains of the terms of reference.
Conclusion
The findings of this study are captured in a 10-step framework which describes practical strategies for establishing a community reference group and terms of reference in Aboriginal health research
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