141 research outputs found
Origin of Life
The evolution of life has been a big enigma despite rapid advancements in the
fields of biochemistry, astrobiology, and astrophysics in recent years. The
answer to this puzzle has been as mind-boggling as the riddle relating to
evolution of Universe itself. Despite the fact that panspermia has gained
considerable support as a viable explanation for origin of life on the Earth
and elsewhere in the Universe, the issue remains far from a tangible solution.
This paper examines the various prevailing hypotheses regarding origin of life
like abiogenesis, RNA World, Iron-sulphur World, and panspermia; and concludes
that delivery of life-bearing organic molecules by the comets in the early
epoch of the Earth alone possibly was not responsible for kick-starting the
process of evolution of life on our planet.Comment: 32 pages, 8 figures,invited review article, minor additio
Measurements of DT alpha particle loss near the outer midplane of TFTR
Measurements of DT alpha particle loss to the outer midplane region of TFTR have been made using a radially movable scintillator detector. The conclusion from this data is that mechanisms determining the DT alpha loss to the outer midplane are not substantially different from those for DD fusion products. Some of these results are compared with a simplified theoretical model for TF ripple-induced alpha loss, which is expected to be the dominant classical alpha loss mechanism near the outer midplane. An example of plasma-driven MHD-induced alpha particle loss is shown, but no signs of any ``collective`` alpha instability-induced alpha loss have yet been observed
Environmental Design for Dementia Care Towards more Meaningful Experiences through Design
Dementia is generally considered to be one of the most pressing societal issues now and in the years to come. Although insights from different disciplines have contributed to a better understanding of dementia and the development of interventions targeting dementia symptoms, there is a lack of integration of insights from these different perspectives for the purposes of design for dementia. The aim of this paper is to show how insights from environmental psychology and advances in technology can inform a user-centred multidisciplinary design approach. To this end, first a brief meta-review of (systematic) reviews from the fields of assistive technology for dementia care and healing environments research is presented, after which gaps and opportunities for a multidisciplinary design approach are identified. To illustrate what such an approach could look like, two exploratory case studies are presented in which technology-enhanced prototypes of an experience handrail (aimed at facilitating wayfinding by providing meaningful sensory experiences) and a virtual nature installation (aimed at providing relaxation and stimulating social engagement) were implemented at a Dutch care centre for people with dementia. Preliminary evaluations indicate that these designs contribute to the wellbeing of people with dementia and confirm the fruitfulness of the design approach presented in this paper. Furthermore, this approach may not only provide a means to optimize existing environments and enhance ease of living, but may also lead to novel solutions to the challenges people with dementia face on a day-to-day basis, and improve their quality of life
Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Overview of recent physics results from the National Spherical Torus Experiment (NSTX)
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