914 research outputs found
An imaging vector magnetograph for the next solar maximum
Researchers describe the conceptual design of a new imaging vector magnetograph currently being constructed at the University of Hawaii. The instrument combines a modest solar telescope with a rotating quarter-wave plate, an acousto-optical tunable prefilter as a blocker for a servo-controlled Fabry-Perot etalon, CCD cameras, and on-line digital image processing. Its high spatial resolution (1/2 arcsec pixel size) over a large field of view (5 by 5 arcmin) will be sufficient to significantly measure, for the first time, the magnetic energy dissipated in major solar flares. Its millisecond tunability and wide spectral range (5000 to 7000 A) enable nearly simultaneous vector magnetic field measurements in the gas-pressure-dominated photosphere and magnetically-dominated chromosphere, as well as effective co-alignment with Solar-A's X ray images. Researchers expect to have the instrument in operation at Mees Solar Observatory (Haleakala) in early 1991. They have chosen to use tunable filters as wavelength-selection elements in order to emphasize the spatial relationships between magnetic field elements, and to permit construction of a compact, efficient instrument. This means that spectral information must be obtained from sequences of images, which can cause line profile distortions due to effects of atmospheric seeing
On the difference between updating the mixing matrix and updating the separation matrix
Raw data for our paper: "Interrelated chemical-microstructural-nanomechanical variations in the structural units of the cuttlebone of Sepia officinalis" DOI: 10.1063/1.499320
The Impact of an Occupation Based Parkinson Caregiver Program on Caregiver\u27s Quality of Life
The goal of the study was to enhance the PD patient’s caregiver’s ability to provide quality care to meet the ever changing needs of a neurodegenerative medical condition along with enhancing quality of life indicators of the caregiver. The community based program covered 7 topics over 4 consecutive weeks. The project design was an experimental one group pre and posttest design. The outcome measurement tool was the Parkinson Caregiver QOL Index. Data was analyzed utilizing a paired t-test for individual questions and the total score on the Parkinson Caregiver QOL Scale. No statistical significance was found between pretest and posttest scores. However, positive improvements were noted on specific components of the scale. Additionally, caregivers self-reported that the course provided valuable and insightful information that will aid both the caregiver and the person with PD. Caregiver burdens and demands are expected to grow as our population ages and chronic conditions are medically managed for longer periods of time. It is essential, that occupational therapists continue to engage in developing research and methods that serve as a guide on best practices to meet the ever changing burdens and demands placed onto the caregiver
Does the Babcock--Leighton Mechanism Operate on the Sun?
The contribution of the Babcock-Leighton mechanism to the generation of the
Sun's poloidal magnetic field is estimated from sunspot data for three solar
cycles. Comparison of the derived quantities with the A-index of the
large-scale magnetic field suggests a positive answer to the question posed in
the title of this paper.Comment: 5 pages, 2 figures, to apper in Astronomy Letter
Solar Flares and Coronal Mass Ejections: A Statistically Determined Flare Flux-CME Mass Correlation
In an effort to examine the relationship between flare flux and corresponding
CME mass, we temporally and spatially correlate all X-ray flares and CMEs in
the LASCO and GOES archives from 1996 to 2006. We cross-reference 6,733 CMEs
having well-measured masses against 12,050 X-ray flares having position
information as determined from their optical counterparts. For a given flare,
we search in time for CMEs which occur 10-80 minutes afterward, and we further
require the flare and CME to occur within +/-45 degrees in position angle on
the solar disk. There are 826 CME/flare pairs which fit these criteria.
Comparing the flare fluxes with CME masses of these paired events, we find CME
mass increases with flare flux, following an approximately log-linear, broken
relationship: in the limit of lower flare fluxes, log(CME mass)~0.68*log(flare
flux), and in the limit of higher flare fluxes, log(CME mass)~0.33*log(flare
flux). We show that this broken power-law, and in particular the flatter slope
at higher flare fluxes, may be due to an observational bias against CMEs
associated with the most energetic flares: halo CMEs. Correcting for this bias
yields a single power-law relationship of the form log(CME mass)~0.70*log(flare
flux). This function describes the relationship between CME mass and flare flux
over at least 3 dex in flare flux, from ~10^-7 to 10^-4 W m^-2.Comment: 28 pages, 16 figures, accepted to Solar Physic
The global oscillation network group site survey. II. Results
The Global Oscillation Network Group (GONG) Project will place a network of instruments around the world to observe solar oscillations as continuously as possible for three years. The Project has now chosen the six network sites based on analysis of survey data from fifteen sites around the world. The chosen sites are: Big Bear Solar Observatory, California; Mauna Loa Solar Observatory, Hawaii; Learmonth Solar Observatory, Australia; Udaipur Solar Observatory, India; Observatorio del Teide, Tenerife; and Cerro Tololo Interamerican Observatory, Chile.
Total solar intensity at each site yields information on local cloud cover, extinction coefficient, and transparency fluctuations. In addition, the performance of 192 reasonable components analysis. An accompanying paper describes the analysis methods in detail; here we present the results of both the network and individual site analyses.
The selected network has a duty cycle of 93.3%, in good agreement with numerical simulations. The power spectrum of the network observing window shows a first diurnal sidelobe height of 3 × 10⁻⁴ with respect to the central component, an improvement of a factor of 1300 over a single site. The background level of the network spectrum is lower by a factor of 50 compared to a single-site spectrum
Design for ground beetle abundance and diversity sampling within the National Ecological Observatory Network
The National Ecological Observatory Network (NEON) will monitor ground beetle populations across a network of broadly distributed sites because beetles are prevalent in food webs, are sensitive to abiotic factors, and have an established role as indicator species of habitat and climatic shifts. We describe the design of ground beetle population sampling in the context of NEON's long-term, continentalscale monitoring program, emphasizing the sampling design, priorities, and collection methods. Freely available NEON ground beetle data and associated field and laboratory samples will increase scientific understanding of how biological communities are responding to land-use and climate change.Peer reviewe
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Dairy consumption and cardiometabolic diseases: systematic review and updated meta-analyses of prospective cohort studies
Purpose of Review Dairy products contain both beneficial and harmful nutrients in relation to cardiometabolic diseases. Here, we
provide the latest scientific evidence regarding the relationship between dairy products and cardiometabolic diseases by
reviewing the literature and updating meta-analyses of observational studies.
Recent Findings We updated our previous meta-analyses of cohort studies on type 2 diabetes, coronary heart disease (CHD), and
stroke with nine studies and confirmed previous results. Total dairy and low-fat dairy (per 200 g/d) were inversely associated with
a 3–4% lower risk of diabetes. Yogurt was non-linearly inversely associatedwith diabetes (RR = 0.86, 95%CI: 0.83–0.90 at 80 g/
d). Total dairy and milk were not associated with CHD (RR~1.0). An increment of 200 g of daily milk intake was associated with
an 8% lower risk of stroke.
Summary The latest scientific evidence confirmed neutral or beneficial associations between dairy products and risk of cardiometabolic
diseases
Decreasing Phosphorus Fertility to Reduce Sweet potato Root Growth During Container-grown Transplant Production
Sweetpotato [Ipomoea batatas (L.) Lam.], grown as an edible ornamental, is propagated in home gardens using locally purchased transplants. However, vigorous growth of sweetpotato limits the period of transplant salability due to root confinement. The objective of the experiment was to evaluate reductions in phosphorus (P) fertility to slow transplant root growth and extend the period of salability. Cuttings were planted into containers and fertilized at 0, 5 (0.0007), 10 (0.0012), 15 (0.0020), 20 (0.0024), and 31 mg P.L-1 (0.0040 oz P.gal-1) using a modified Hoagland solution. All transplants fertilized at 5 mg P.L-1 increased in shoot length, color, and biomass during the first four weeks after planting (WAP) but declined thereafter. Transplant roots fertilized at 5 mg P. L-1 (0.0007 oz P.gal-1) increased in total length, surface area, and volume throughout the six-week production cycle. However, P fertility,15 mg.L-1 (0.0020 oz P.gal-1) resulted in narrower storage roots with lower root volumes. Reducing P fertility from 31 (0.0040 oz P.gal-1) to 5 mg L-1 (0.0007 oz P.gal-1) did not sufficiently slow transplant rooting to prevent roots from reaching container walls to extend the period of salability
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