The future for beef

Beef is a fast-growing, multi -billion dollar industry today in the United States. And the outlook for tomorrow is most favorable. Beef consumption has increased by 26 pounds per capita during the past 15 years, hitting an all-time high of 90 pounds per capita in 1962. During the same period quality has improved, and now. beef commands even wider consumer acceptance than in the mid-1940\u27s. New technology has lowered production and marketing costs. But even a strong, healthy industry must be sensitive to change--and take advantage of new opportunities for growth and improvement. The beef industry is no exception.https://lib.dr.iastate.edu/card_reports/1016/thumbnail.jp

Search for Point Sources of Ultra-High Energy Cosmic Rays Above 40 EeV Using a Maximum Likelihood Ratio Test

We present the results of a search for cosmic ray point sources at energies above 40 EeV in the combined data sets recorded by the AGASA and HiRes stereo experiments. The analysis is based on a maximum likelihood ratio test using the probability density function for each event rather than requiring an a priori choice of a fixed angular bin size. No statistically significant clustering of events consistent with a point source is found.Comment: 7 pages, 7 figures. Accepted for publication in The Astrophysical Journa

A Search for Very High-Energy Gamma Rays from the Missing Link Binary Pulsar J1023+0038 with VERITAS

The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259--63/LS 2883, making it an ideal candidate for the study of high-energy non-thermal emission. It has been the subject of multi-wavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high-energy gamma-ray observations carried out by VERITAS before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that very high-energy gamma rays are produced via an inverse-Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than $\sim$2 G before the disappearance of the radio pulsar and greater than $\sim$10 G afterwards.Comment: 7 pages, 3 figures, accepted for publication in Ap

An upper limit on the electron-neutrino flux from the HiRes detector

Air-fluorescence detectors such as the High Resolution Fly's Eye (HiRes) detector are very sensitive to upward-going, Earth-skimming ultrahigh energy electron-neutrino-induced showers. This is due to the relatively large interaction cross sections of these high-energy neutrinos and to the Landau-Pomeranchuk-Migdal (LPM) effect. The LPM effect causes a significant decrease in the cross sections for bremsstrahlung and pair production, allowing charged-current electron-neutrino-induced showers occurring deep in the Earth's crust to be detectable as they exit the Earth into the atmosphere. A search for upward-going neutrino-induced showers in the HiRes-II monocular dataset has yielded a null result. From an LPM calculation of the energy spectrum of charged particles as a function of primary energy and depth for electron-induced showers in rock, we calculate the shape of the resulting profile of these showers in air. We describe a full detector Monte Carlo simulation to determine the detector response to upward-going electron-neutrino-induced cascades and present an upper limit on the flux of electron-neutrinos.Comment: 13 pages, 3 figures. submitted to Astrophysical Journa

Search for Correlations between HiRes Stereo Events and Active Galactic Nuclei

We have searched for correlations between the pointing directions of ultrahigh energy cosmic rays observed by the High Resolution Fly's Eye experiment and Active Galactic Nuclei (AGN) visible from its northern hemisphere location. No correlations, other than random correlations, have been found. We report our results using search parameters prescribed by the Pierre Auger collaboration. Using these parameters, the Auger collaboration concludes that a positive correlation exists for sources visible to their southern hemisphere location. We also describe results using two methods for determining the chance probability of correlations: one in which a hypothesis is formed from scanning one half of the data and tested on the second half, and another which involves a scan over the entire data set. The most significant correlation found occurred with a chance probability of 24%.Comment: 13 pages, 1 table, 5 figure

Search for Dark Matter Annihilation in the Galactic Center with IceCube-79

The Milky Way is expected to be embedded in a halo of dark matter particles, with the highest density in the central region, and decreasing density with the halo-centric radius. Dark matter might be indirectly detectable at Earth through a flux of stable particles generated in dark matter annihilations and peaked in the direction of the Galactic Center. We present a search for an excess flux of muon (anti-) neutrinos from dark matter annihilation in the Galactic Center using the cubic-kilometer-sized IceCube neutrino detector at the South Pole. There, the Galactic Center is always seen above the horizon. Thus, new and dedicated veto techniques against atmospheric muons are required to make the southern hemisphere accessible for IceCube. We used 319.7 live-days of data from IceCube operating in its 79-string configuration during 2010 and 2011. No neutrino excess was found and the final result is compatible with the background. We present upper limits on the self-annihilation cross-section, \left, for WIMP masses ranging from 30 GeV up to 10 TeV, assuming cuspy (NFW) and flat-cored (Burkert) dark matter halo profiles, reaching down to $\simeq 4 \cdot 10^{-24}$ cm$^3$ s$^{-1}$, and $\simeq 2.6 \cdot 10^{-23}$ cm$^3$ s$^{-1}$ for the $\nu\overline{\nu}$ channel, respectively.Comment: 14 pages, 9 figures, Submitted to EPJ-C, added references, extended limit overvie

Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar

We study the process $e^+e^-\to J/\psi\pi^{+}\pi^{-}$ with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454 $\mathrm{fb^{-1}}$. We investigate the $J/\psi \pi^{+}\pi^{-}$ mass distribution in the region from 3.5 to 5.5 $\mathrm{GeV/c^{2}}$. Below 3.7 $\mathrm{GeV/c^{2}}$ the $\psi(2S)$ signal dominates, and above 4 $\mathrm{GeV/c^{2}}$ there is a significant peak due to the Y(4260). A fit to the data in the range 3.74 -- 5.50 $\mathrm{GeV/c^{2}}$ yields a mass value $4244 \pm 5$ (stat) $\pm 4$ (syst)$\mathrm{MeV/c^{2}}$ and a width value $114 ^{+16}_{-15}$ (stat)$\pm 7$(syst)$\mathrm{MeV}$ for this state. We do not confirm the report from the Belle collaboration of a broad structure at 4.01 $\mathrm{GeV/c^{2}}$. In addition, we investigate the $\pi^{+}\pi^{-}$ system which results from Y(4260) decay

Quantifying extinction risk and forecasting the number of impending Australian bird and mammal extinctions

A critical step towards reducing the incidence of extinction is to identify and rank the species at highest risk, while implementing protective measures to reduce the risk of extinction to such species. Existing global processes provide a graded categorisation of extinction risk. Here we seek to extend and complement those processes to focus more narrowly on the likelihood of extinction of the most imperilled Australian birds and mammals. We considered an extension of existing IUCN and NatureServe criteria, and used expert elicitation to rank the extinction risk to the most imperilled species, assuming current management. On the basis of these assessments, and using two additional approaches, we estimated the number of extinctions likely to occur in the next 20 years. The estimates of extinction risk derived from our tighter IUCN categorisations, NatureServe assessments and expert elicitation were poorly correlated, with little agreement among methods for which species were most in danger – highlighting the importance of integrating multiple approaches when considering extinction risk. Mapped distributions of the 20 most imperilled birds reveal that most are endemic to islands or occur in southern Australia. The 20 most imperilled mammals occur mostly in northern and central Australia. While there were some differences in the forecasted number of extinctions in the next 20 years among methods, all three approaches predict further species loss. Overall, we estimate that another seven Australian mammals and 10 Australian birds will be extinct by 2038 unless management improves