Antiquark nuggets as dark matter: New constraints and detection prospects

Current evidence for dark matter in the universe does not exclude heavy composite nuclear-density objects consisting of bound quarks or antiquarks over a significant range of masses. Here we analyze one such proposed scenario, which hypothesizes antiquark nuggets with a range of log10(B) = 24-30 with specific predictions for spectral emissivity via interactions with normal matter. We find that, if these objects make up the majority of the dark matter density in the solar neighborhood, their radiation efficiency in solids is marginally constrained, due to limits from the total geothermal energy budget of the Earth. At allowed radiation efficiencies, the number density of such objects can be constrained to be well below dark matter densities by existing radio data over a mass range currently not restricted by other methods.Comment: 6 pages, 3 figures, revised references; submitted to PR

The Impact of Local: Exploring Availability and Location on Food Buying Decisions

The term “local food ” is a buzzword in the food industry for consumers. However, when consumers make food-purchasing decisions, do they look for the specif ic growing locations and consider the seasonality of the product? In this study, researchers used focus groups to determine the impact growing location and months of availability have on consumers’ purchasing decisions in order to identify effective communication strategies when communicating about local food. The theoretical framework of framing and cognitive dissonance informed this study. The findings from this research indicated consumers defined local food as grown in a certain area, state, or region. Additionally, results indicated consumers make food-buying decisions based on personal preference, versatility, health benef its, preparation, and seasonal cooking. Overall, consumers’ decisions to buy produce were not impacted by growing season, but rather by their preference for a specific product. Participants noted most produce is available year round nationally. The researchers recommend communicators focus on developing message strategies framed toward the purchasing attributes identified by the participants instead of growing location and availability. Future research should continue to examine the impact of different frames on consumer food-purchasing decisions and how consumers perceive specific message frames

The Critical Target Audience: Communicating Water Conservation Behaviors to Critical Thinking Styles

Although water covers approximately 70% of the planet, only a fraction is fresh water, and even less is used as a major source of drinking water. With the continuous increase in the amount of water used in modern standards of living, the quantity of water available is decreasing. The public is beginning to understand water needs to be conserved and they must play a role in water conservation. While previous literature examined how the majority of messages were catered toward the cost-effectiveness of conserving water, this study proposed how using a specific audience attribute could affect behaviors. The purpose of the study was to determine if critical thinking style can be used in the development of future communication strategies to improve water conservation behaviors. The findings of this study provided evidence of a relationship between critical thinking style and the level of engagement in water conservation behaviors. Recommendations suggested targeting the two constructs of critical thinking style, information seekers and engagers, in two different ways. Since the seekers prefer to gather information by seeking the sources themselves, communicators should focus on developing quality information about water conservation and placing it in easily accessible communications channels for the information seeker. On the other hand, a different communications approach should be taken with the engagers, who prefer to learn through their environment. Communicators should focus on communicating to the engager through the environment in word-of-mouth situations using traditional means such as opinion leaders as well as social media

Experimental Limit on the Cosmic Diffuse Ultra-high Energy Neutrino Flux

We report results from 120 hours of livetime with the Goldstone Lunar Ultra-high energy neutrino Experiment (GLUE). The experiment searches for <10 ns microwave pulses from the lunar regolith, appearing in coincidence at two large radio telescopes separated by 22 km and linked by optical fiber. Such pulses would arise from subsurface electromagnetic cascades induced by interactions of >= 100 EeV neutrinos in the lunar regolith. No candidates are yet seen, and the implied limits constrain several current models for ultra-high energy neutrino fluxes.Comment: 4 pages, 4 figures, revtex4 style. New intro section, Fig. 2, Fig 4; in final PRL revie

Origin of immature loggerhead sea turtles (Caretta caretta) at Hutchinson Island, Florida: evidence from mtDNA markers

Loggerhead sea turtles (Caretta caretta) are migratory, long-lived, and slow maturing. They are difficult to study because they are seen rarely and their habitats range over vast stretches of the ocean. Movements of immature turtles between pelagic and coastal developmental habitats are particularly difficult to investigate because of inadequate tagging technologies and the difficulty in capturing significant numbers of turtles at sea. However, genetic markers found in mitochondrial DNA (mtDNA) provide a basis for predicting the origin of juvenile turtles in developmental habitats. Mixed stock analysis was used to determine which nesting populations were contributing individuals to a foraging aggregation of immature loggerhead turtles (mean 63.3 cm straight carapace length [SCL]) captured in coastal waters off Hutchinson Island, Florida. The results indicated that at least three different western Atlantic loggerhead sea turtle subpopulations contribute to this group: south Florida (69%), Mexico (20%), and northeast Florida-North Carolina (10%). The conservation and management of these immature sea turtles is complicated by their multinational genetic demographics

The Role of Dissonance and Schema: An Exploration of Florida Public Perception after the DWH Oil Spill

The agricultural and natural resources industries are no stranger to crises, particularly, large-scale crises such as the Deepwater Horizon (DWH) oil spill in 2010. Crises have an impact on how consumers view a product, and ultimately, can impact their decisions to buy or not buy products from an industry that has experienced a crisis. This qualitative study sought to evaluate consumer perceptions of Gulf seafood after the DWH oil spill, and explored the influence of schema and cognitive dissonance on consumers’ intent to consume or purchase Gulf seafood after the DWH oil spill. Focus group discussion with seafood consumers revealed participants had a pre-existing schema associated with local seafood, seafood origin, health benefits of seafood, and the safety of seafood. Dissonance was observed when participants balanced their pre-existing schemas with knowledge of the DWH oil spill as the participants discussed buying seafood, not buying seafood, and buying seafood with fear. From the findings of this study, researchers and communicators may have a better understanding of the decision-making process associated with buying a product after a crisis. Recommendations were made for agricultural communicators to develop personal messages and stories to help consumers overcome any remaining fear or dissonance associated with Gulf seafood

Search for gamma-rays from M31 and other extragalactic objects

Although the existence of fluxes of gamma-rays of energies 10 to the 12th power eV is now established for galactic sources, the detection of such gamma-rays from extragalactic sources has yet to be independently confirmed in any case. The detection and confirmation of such energetic photons is of great astrophysical importance in the study of production mechanisms for cosmic rays, and other high energy processes in extragalactic objects. Observations of m31 are discussed. It is reported as a 10 to the 12th power eV gamma-ray source. Flux limits on a number of other extragalactic objects chosen for study are given

Search for gamma-rays above 400 GeV from Geminga

Observations of Geminga made at the Whipple Observatory using the atmospheric Cherenkov technique during the moonless periods of November 1983 to February 1984 and November 1984 till February 1985 were examined for evidence for the emission of gamma rays with energy in excess of approx 400 GeV. Evidence of either a steady flux or a flux pulsed with a period near 60 seconds were studied. In neither case was any significant effect observed, enabling the establishment 3 of sigma upper limits of 5.5 x 10 to the -11th power photons/sq cm/s and 2.0 x 10 to the -11th power photons/sq cm/s for the steady and pulsed emission respectively. The limit to the pulsed flux is approximately a factor of six below that predicted

Application of imaging to the atmospheric Cherenkov technique

Turver and Weekes proposed using a system of phototubes in the focal plane of a large reflector to give an air Cherenkov camera for gamma ray astronomy. Preliminary results with a 19 element camera have been reported previously. In 1983 the camera was increased to 37 pixels; it has now been routinely operated for two years. A brief physical description of the camera, its mode of operation, and the data reduction procedures are presented. The Monte Carlo simultations on which these are based on also reviewed

Observations of the Crab Nebula at energies 4.10(11)

Since the development of gamma-ray astronomical telescopes, the Crab Nebula has been a prime target for observations. From 100 to 1000 MeV, the pulsar PSR0531 is the dominant source with a light-curve similar to that seen at lower energies; there is also some evidence for longterm amplitude variations but none for emission from the Nebula itself. In the very high energy gamma-ray region there have been reported detections of pulsed emission with longterm time variations from minutes to months. Recently a pulsed flux has been reported that resisted over a long time interval. The detection of a flux from the Nebula at the 3 sigma level at energies of 3x1011eV was reported; there was no evidence of periodic emissions on any time scale during the three years of observations. A new measurement of very high energy gamma rays from the Crab Nebula is reported using the imaging system on the Whipple Observatory 10m reflector