7,047 research outputs found
Aquatic Macrophytes of Two Small Northwest Arkansas Reservoirs
Lake Fayetteville and Lake Wedington are small reservoirs of about the same size and age that are located in northwestern Arkansas. We collected macrophytes from eleven transects around each reservoir in the autumn of 1993. Justicia (waterwillow), Typha (cat-tail), Scirpus (bulrush), Potamogeton (pondweed), and Zannichellia (horned pondweed) occur in both reservoirs. Justicia occurs most commonly in both reservoirs. The macrophytes of Lake Wedington are organized in a characteristic zonation pattern with bands from shore toward open water of emergent, floating-leaved, then submersed macrophytes. Macrophyte zonation was not as evident in Lake Fayetteville because of the low occurrence of floating leaved and submersed macrophytes in1993. Early studies of Lake Wedington found that the dominant macrophytes were Cyperus, Echinochloa, Lotus, and Sagittaria, all of which were absent during this study. Potamogeton, Scirpus, and Typha were also found to be dominant during 1952 studies, but occurred in lesser amounts in the current study. Previous studies (1956, 1967, 1977) on Lake Fayetteville stated that Sagittaria and Nelumbo were dominant macrophytes, but we found none in1993. Juncus, Potamogeton, Scirpus, and Typha were common in the early studies but occurred infrequently in our collections. Macrophyte composition in Lake Fayetteville in 1993 was attributable to an herbicide application that occurred in spring, 1992. As for the changes in Lake Wedington, we assume that the Justicia has out-competed those macrophytes that were in the reservoir in1952, or that normal lake ontogeny during the intervening 40 years has altered habitat conditions to now favor Justicia
Consumer Awareness of the Jersey Fresh Promotional Program
The Jersey Fresh marketing program, one of the nationâs leading examples of state-sponsored agricultural marketing promotion, enables consumers to easily identify quality fresh produce from New Jersey by promoting locally grown fruits and vegetables in the market with Jersey Freshâs logos. This study utilizes a consumer survey to evaluate the effectiveness of the Jersey Fresh Program in terms of the impact the promotional logos have on consumers. The results of this study provide valuable information that may be used to improve the Jersey Fresh Program, and also may be used in the promotion of other New Jersey farm products as well as products in other states which have similar promotional programs. Among other things, this study demonstrated that the Jersey Fresh promotional program has created significant brand awareness among New Jersey consumers and that consumers are willing to purchase Jersey Fresh produce when itâs available. Consumers reported seeing the Jersey Fresh logo most frequently on in-store produce displays. Whatâs more, women were more likely than men to be aware of Jersey Fresh, as were married people. Survey participants believed Jersey Fresh produce to be better than produce in other states in terms of quality and freshness. Moreover, consumers associate the Jersey Fresh logo with locally grown, quality produce. Suggestions that emerged from the study include increasing the availability of Jersey Fresh produce during the production seasons would ensure continued consumer patronage. Also, increasing promotions of Jersey Fresh produce in supermarkets may further increase the popularity of Jersey Fresh produce. The study showed that a vii majority of consumers were willing to pay only a small percentage premium for Jersey Fresh produce over the market prices for other fresh produce; therefore, significant price differentials are not recommended for Jersey Fresh produce. The results of this study lead to a better understanding of New Jersey consumersâ shopping behavior, their preferences towards local produce and their demographic composition. The results may be especially encouraging to those developing marketing strategies for Jersey Fresh produce or for other similar New Jersey consumer products.Consumer/Household Economics, Marketing,
Returns to the Jersey Fresh Promotional Program: The Impacts of Promotional Expenditures on Farm Cash Receipts in New Jersey
In 1984, the Jersey Fresh program was implemented by the New Jersey Department of Agriculture and was the first state-funded marketing campaign for agricultural products produced in New Jersey. In an effort to spur demand for New Jersey farm products, this program was designed to increase consumer awareness of the stateâs agricultural products as well as to encourage food retailers to promote Jersey Fresh products. With funding from the USDAâs Federal-State Marketing Improvement Program, the New Jersey Department of Agriculture commissioned this study to determine the impact of Jersey Fresh promotion on farmer cash receipts in New Jersey. The econometric analysis was focused on the fruit and vegetable sectors, the primary commodity areas expected to benefit most directly from Jersey Fresh promotion. Study results show that: âą For every dollar spent on the Jersey Fresh Promotional Program through 2000, New Jerseyâs agricultural fruit and vegetable sector revenues increased by 22.95 of sales in agricultural support industries and other related industries. âą In total, each dollar spent on Jersey Fresh promotion resulted in 1.16 million spent on the Jersey Fresh program in 2000 increased fruit and vegetable cash receipts by 26.6 million in economic activity within agricultural support industries. The total statewide economic impact of the Jersey Fresh program was therefore an estimated 2.2 million in 2000 due to the increased economic activity attributable to Jersey Fresh promotion. Comparing this return to the 2000 program budget of $1.16 million, the Jersey Fresh program appears to be better than revenue-neutral.Agribusiness, Marketing,
Radius constraints from high-speed photometry of 20 low-mass white dwarf binaries
We carry out high-speed photometry on 20 of the shortest-period, detached
white dwarf binaries known and discover systems with eclipses, ellipsoidal
variations (due to tidal deformations of the visible white dwarf), and Doppler
beaming. All of the binaries contain low-mass white dwarfs with orbital periods
less than 4 hr. Our observations identify the first eight tidally distorted
white dwarfs, four of which are reported for the first time here, which we use
to put empirical constraints on the mass-radius relationship for extremely
low-mass (<0.30 Msun) white dwarfs. We also detect Doppler beaming in several
of these binaries, which confirms the high-amplitude radial-velocity
variability. All of these systems are strong sources of gravitational
radiation, and long-term monitoring of those that display ellipsoidal
variations can be used to detect spin-up of the tidal bulge due to orbital
decay.Comment: 14 pages, 5 figures, accepted for publication in The Astrophysical
Journa
Constraints on Type Ia Supernova Progenitor Companions from Early Ultraviolet Observations with Swift
We compare early ultraviolet (UV) observations of Type Ia Supernovae (SNe Ia)
with theoretical predictions for the brightness of the shock associated with
the collision between SN ejecta and a companion star. Our simple method is
independent of the intrinsic flux from the SN and treats the flux observed with
the Swift/Ultra-Violet Optical Telescope (UVOT) as conservative upper limits on
the shock brightness. Comparing this limit with the predicted flux for various
shock models, we constrain the geometry of the SN progenitor-companion system.
We find the model of a 1 M_sun red supergiant companion in Roche lobe overflow
to be excluded at a 95% confidence level for most individual SNe for all but
the most unfavorable viewing angles. For the sample of 12 SNe taken together,
the upper limits on the viewing angle are inconsistent with the expected
distribution of viewing angles for RG stars as the majority of companions with
high confidence. The separation distance constraints do allow MS companions. A
better understanding of the UV flux arising from the SN itself as well as
continued UV observations of young SNe Ia will further constrain the possible
progenitors of SNe Ia.Comment: accepted versio
Population of 13Be in a Nucleon Exchange Reaction
The neutron-unbound nucleus 13Be was populated with a nucleon-exchange
reaction from a 71 MeV/u secondary 13B beam. The decay energy spectrum was
reconstructed using invariant mass spectroscopy based on 12Be fragments in
coincidence with neutrons. The data could be described with an s-wave resonance
at E = 0.73(9) MeV with a width of Gamma = 1.98(34) MeV and a d-wave resonance
at E = 2.56(13) MeV with a width of Gamma = 2.29(73) MeV. The observed spectral
shape is consistent with previous one-proton removal reaction measurements from
14B.Comment: Published in Phys. Rev.
Fine particle pH and the partitioning of nitric acid during winter in the northeastern United States
Particle pH is a critical but poorly constrained quantity that affects many aerosol processes and properties, including aerosol composition, concentrations, and toxicity. We assess PM1 pH as a function of geographical location and altitude, focusing on the northeastern U.S., based on aircraft measurements from the Wintertime Investigation of Transport, Emissions, and Reactivity campaign (1 February to 15 March 2015). Particle pH and water were predicted with the ISORROPIA-II thermodynamic model and validated by comparing predicted to observed partitioning of inorganic nitrate between the gas and particle phases. Good agreement was found for relative humidity (RH) above 40%; at lower RH observed particle nitrate was higher than predicted, possibly due to organic-inorganic phase separations or nitrate measurement uncertainties associated with low concentrations (nitrateâ\u3câ1â”gâmâ3). Including refractory ions in the pH calculations did not improve model predictions, suggesting they were externally mixed with PM1 sulfate, nitrate, and ammonium. Sample line volatilization artifacts were found to be minimal. Overall, particle pH for altitudes up to 5000âm ranged between â0.51 and 1.9 (10th and 90th percentiles) with a study mean of 0.77â±â0.96, similar to those reported for the southeastern U.S. and eastern Mediterranean. This expansive aircraft data set is used to investigate causes in variability in pH and pH-dependent aerosol components, such as PM1 nitrate, over a wide range of temperatures (â21 to 19°C), RH (20 to 95%), inorganic gas, and particle concentrations and also provides further evidence that particles with low pH are ubiquitous
Ultraviolet Light Curves of Supernovae with Swift Uvot
We present ultravioliet (UV) observations of supernovae (SNe) obtained with
the UltraViolet/Optical Telescope (UVOT) on board the Swift spacecraft. This is
the largest sample of UV light curves from any single instrument and covers all
major SN types and most subtypes. The UV light curves of SNe Ia are fairly
homogenous while SNe Ib/c and IIP show more variety in their light curve
shapes. The UV-optical colors clearly differentiate SNe Ia and IIP,
particularly at early times. The color evolution of SNe IIP, however, makes
their colors similar to SNe Ia at about 20 days after explosion. SNe Ib/c are
shown to have varied UV-optical colors. The use of UV colors to help type SNe
will be important for high redshift SNe discovered in optical observations.
These data can be added to ground based optical and near infrared data to
create bolometric light curves of individual objects and as checks on generic
bolometric corrections used in the absence of UV data. This sample can also be
compared with rest-frame UV observations of high redshift SNe observed at
optical wavelengths.Comment: 11 pages, including 8 figures. Submitted to A
Geometrical Finiteness, Holography, and the BTZ Black Hole
We show how a theorem of Sullivan provides a precise mathematical statement
of a 3d holographic principle, that is, the hyperbolic structure of a certain
class of 3d manifolds is completely determined in terms of the corresponding
Teichmuller space of the boundary. We explore the consequences of this theorem
in the context of the Euclidean BTZ black hole in three dimensions.Comment: 6 pages, Latex, Version to appear in Physical Review Letter
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