30 research outputs found
The Effect of A Fifty Percent Leaf Harvest From Three Varieties of Collards (Brassica Oleracea(L)/Cultivar Group Acephala) Cropped at Selected Intervals When Grown in A Wiregrass Tunnel House
A study was conducted to determine the effects of a 50% leaf harvest from ‘Heirloom’, ‘Georgia’, and ‘Hi-Crop Hybrid’ collards on yield, when leaves were removed at 18-, 21-, and 25- day intervals, over four harvest periods of 102, 127, 152, and 177 days after transplanting in a Wiregrass Tunnel House. The experimental design used was a split-split plot with three replications, where harvest periods were main plots, cropping intervals (3) were sub-plots, and varieties were sub-sub-plots. Yield data (lbs./acre) showed significant interactions between harvest periods x cropping intervals for leaf numbers and yield, harvest periods x varieties, and cropping intervals x varieties. The 18-day cropping interval had the highest yields over all harvest periods; while varieties responded differently for each harvest period, and cropping intervals. ‘Hi-Crop Hybrid’ had the highest yield over all harvest periods and cropping intervals, followed by ‘Georgia ‘and ‘Heirloom.
Where are the Fossils of the First Galaxies? I. Local Volume Maps and Properties of the Undetected Dwarfs
We present a new method for generating initial conditions for LCDM N-body
simulations which provides the dynamical range necessary to follow the
evolution and distribution of the fossils of the first galaxies on Local
Volume, 5-10 Mpc, scales. The initial distribution of particles represents the
position, velocity and mass distribution of the dark and luminous halos
extracted from pre-reionization simulations. We confirm previous results that
ultra-faint dwarfs have properties compatible with being well preserved fossils
of the first galaxies. However, because the brightest pre-reionization dwarfs
form preferentially in biased regions, they most likely merge into non-fossil
halos with circular velocities >20-30 km/s. Hence, we find that the maximum
luminosity of true-fossils in the Milky Way is L_V<10^5 L_solar, casting doubts
on the interpretation that some classical dSphs are true-fossils. In addition,
we argue that most ultra-faints at small galactocentric distance, R<50 kpc, had
their stellar properties modified by tides, while a large population of fossils
is still undetected due to their extremely low surface brightness log(Sigma_V)
< -1.4. We estimate that the region outside R_50 (~ 400 kpc) up to 1 Mpc from
the Milky Way contains about a hundred true fossils of the first galaxies with
V-band luminosities 10^3 - 10^5 L_solar and half-light radii, r_hl ~ 100-1000
pc.Comment: published in ApJ October 2011 with minor revisions V. 741 article ID.
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Where are the Fossils of the First Galaxies? II. True Fossils, Ghost Halos, and the Missing Bright Satellites
We use a new set of cold dark matter simulations of the local universe to
investigate the distribution of fossils of primordial dwarf galaxies within,
and around the Milky Way. Throughout, we build upon previous results showing
agreement between the observed stellar properties of a subset of the
ultra-faint dwarfs and our simulated fossils. Here, we show that fossils of the
first galaxies have galactocentric distributions and cumulative luminosity
functions consistent with observations. In our model there are ~ 300 luminous
satellites orbiting the Milky Way, ~50-70% of which are well preserved fossils,
with this fraction decreasing with galactocentric distance. Within the Milky
Way virial radius, the majority of these fossils have luminosities L_V<10^5
L_solar. This work produces an overabundance of bright dwarf satellites (L_V >
10^4 L_solar) with respect to observations where observations are nearly
complete. The "bright satellite problem" is most evident in the outer parts of
the Milky Way. We estimate that, although relatively bright, the primordial
stellar populations are very diffuse, producing a population with surface
brightnesses below surveys` detection limits and are easily stripped by tidal
forces. Although we cannot yet present unmistakable evidence for the existence
of the fossils of first galaxies in the Local Group, the results of our studies
suggest observational strategies that may demonstrate their existence.
Primarily, the detection of "ghost halos" of primordial stars around isolated
dwarfs would prove that stars formed in minihalos (M<10^8 M_solar) before
reionization, and strongly suggest that at least a fraction of the ultra-faint
dwarfs are fossils of the first galaxies.Comment: publishing in ApJ with minor revisions in October 2011 V. 741 article
ID. 1
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US Renal Data System 2017 Annual Data Report: Epidemiology of Kidney Disease in the United States.
UNC System Smoke-Free Campus Initiative
The state of North Carolina is one of the leading producers of tobacco in the United States. As such, the tobacco industry has played a significant role in North Carolina politics for decades. The relationship between big tobacco companies and the state legislature has resulted in a restrictive policy for University of North Carolina System schools. General Statute 143, Article 64, Sections 595-601 establish that UNC System schools cannot restrict campus tobacco use farther than 100 feet from buildings, with the exception of health science campuses. Originating in Honors 2000, our group has conducted collaborative research to advocate for legislative change for over a year. Now, with support from the Student Government Association at East Carolina University, the ECU Faculty Senate, and the statewide Association of Student Governments, we are well-positioned to amend the current legislation. Our proposed bill amendment has also gained approval from Representative Kandie Smith and Representative Donna White, who will act as sponsors to advance our bill through the North Carolina General Assembly
Influence of Mental Health on Disaster Preparedness: Findings from the Behavioral Risk Factor Surveillance System, 2007–2009
Palynomorph biostratigraphy of the Cretaceous (Hauterivian–lower Cenomanian) of the South Sallum Well, North Western Desert, Egypt
Patients’ experiences of support for learning to live with diabetes to promote health and well-being: A lifeworld phenomenological study
Assessing carbon dioxide emission reduction potentials of improved manufacturing processes using multiregional input output frameworks
Science with the Murchison Widefield Array : Phase l results and Phase II opportunities
The Murchison Widefield Array (MWA) is an open access telescope dedicated to studying the low-frequency (80-300 MHz) southern sky. Since beginning operations in mid-2013, the MWA has opened a new observational window in the southern hemisphere enabling many science areas. The driving science objectives of the original design were to observe 21 cm radiation from the Epoch of Reionisation (EoR), explore the radio time domain, perform Galactic and extragalactic surveys, and monitor solar, heliospheric, and ionospheric phenomena. All together programs recorded 20 000 h producing 146 papers to date. In 2016, the telescope underwent a major upgrade resulting in alternating compact and extended configurations. Other upgrades, including digital back-ends and a rapid-response triggering system, have been developed since the original array was commissioned. In this paper, we review the major results from the prior operation of the MWA and then discuss the new science paths enabled by the improved capabilities. We group these science opportunities by the four original science themes but also include ideas for directions outside these categories