Highest Energy Cosmic Rays

We review the current state and future prospect of ultra high energy cosmic ray physics and the relationship between cosmic rays and gamma-ray astrophysics.Comment: 12 pages, in the proceedings of the Gamma 2004 Symposium on High-Energy Gamma-Ray Astronomy, Heidelberg, July, 2004 (AIP Proceedings Series

Converting neutron stars into strange stars

If strange matter is formed in the interior of a neutron star, it will convert the entire neutron star into a strange star. The proposed mechanisms are reviewed for strange matter seeding and the possible strange matter contamination of neutron star progenitors. The conversion process that follows seeding and the recent calculations of the conversion timescale are discussed

Consumer behaviour concerning food safety in Brazil and New Zealand : modelling food safety risk in the home : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology (Food Safety) at Massey University, Manawatu, New Zealand

Foodborne illnesses are among the most widespread public health issues, killing about 2.2 million people annually worldwide, and costing hundreds of billions of US dollars for governments, companies, families and consumers. In Brazil, foodborne illness in the home accounts for 44% of identified disease outbreaks and in New Zealand it represents 27% of notifiable disease outbreaks. Several studies have investigated aspects of consumer behaviour concerning food safety, but it remains a challenge to obtain a full picture of critical control points (CCPs) and key factors contributing to food contamination, pathogen growth or survival, when the food is under the consumer’s responsibility. This study aimed to assess threats to food safety in the home in Brazil and New Zealand. From August 2011 to March 2012, survey questionnaires from 2,775 consumers most responsible for cooking in the home in Brazil were collected. From September 2012 to November 2012, 658 households in New Zealand responded to the same survey. Both surveys found similar CCPs with the potential to threaten food safety in the domestic environment – food preparation, cooking and handling leftovers. Information from New Zealand suggests that choosing and purchasing food, and for Brazil food transportation, are also steps of concern. The age, marital status, gender, ethnicity, first-aid in response to illness and the way a person learned to cook had a significant influence in the risky practices of consumers in both countries, suggesting that similar consumer behaviour concerning food safety can be found in countries of substantially different degrees of economic development and culture. The young, the men, socioeconomic minorities, people most susceptible to illness and ethnic groups were people of most concern, often ranked at-risk, demanding special attention of public health authorities in both countries. The CCPs of most concern and contributing factors identified in this study were officially reported in New Zealand, helping to validate the methodology used in this study and its possible use in other countries. Furthermore, food safety educational campaigns built on the steps of most concern and groups ranked at moderate or high risk, have the potential to be most effective in reducing food poisoning in the home

Asset distribution, inequality, and growth

With the recent resurgence of interest in equity, inequality, and growth, the possibility of a negative relationship between inequality and economic growth, has received renewed interest in the literature. Faced with the prospect that high levels of inequality may persist, and give rise to poverty traps, policymakers are paying more attention to the distributional implications of macroeconomic policies. Because high levels of inequality may hurt overall growth, policymakers are exploring measures to promote growth and equity at the same time. How the consequences of inequality are analyzed, along with the possible cures, depends partly on how inequality is measured. The authors use assets (land) rather than income - and a GMM estimator - to examine the robustness of the relationship between inequality and growth that has been observed in the cross-sectional literature, but has been drawn into question by recent studies using panel techniques. They find evidence that asset inequality - but not income inequality - has a relatively large negative impact on growth. They also find that a highly unequal distribution of assets reduces the effectiveness of educational interventions. This means that policymakers should be more concerned about households'access to assets, and to the opportunities associated with them, than about the distribution of income. Long-term growth might be improved by measures to prevent large jumps in asset inequality - possibly irreversible asset loss because of exogenous shocks - and by policies to facilitate asset accumulation by the poor.International Terrorism&Counterterrorism,Economic Theory&Research,Environmental Economics&Policies,Poverty Impact Evaluation,Services&Transfers to Poor,Inequality,Governance Indicators,Economic Theory&Research,Environmental Economics&Policies,Achieving Shared Growth

ASSET OWNERSHIP AND WORKING CAPITAL CONSTRAINTS IN A POST-REFORM ENVIRONMENT: IMPLICATIONS FOR SECOND GENERATION REFORMS IN ZAMBIA

Using a 5,000 household panel from Zambia, we find that asset ownership, but not access to fertilizer, has an extremely important impact on output and that investment in oxen would yield returns above the market rate. Policies should thus focus on asset ownership more than on short term working capital.Community/Rural/Urban Development, Consumer/Household Economics,

Gamma-Ray Constraints on Neutralino Dark Matter Clumps in the Galactic Halo

According to high resolution cold dark matter (CDM) simulations, large virialized halos are formed through the constant merging of smaller halos formed at earlier times. In particular, the halo of our Galaxy may have hundreds of dark matter clumps. The annihilation of dark matter particles such as the neutralino in these clumps generates $\gamma$-ray fluxes that can potentially be detected by future experiments such as GLAST. We find that, depending on the parameters of the clump density profile and on the distribution of clumps in the Galactic halo, the contribution to the diffuse $\gamma$-ray background from clumps can constrain the properties of neutralinos such as the mass and annihilation cross section. We model the density profile of clumps by three representative dark matter profiles: singular isothermal spheres (SIS), Moore profiles, and Navarro, Frenk and White (NFW) density profiles and calculate the spectrum and angular distribution in the sky of the $\gamma$-ray flux due to neutralino annihilation in the clumpy halo of the Galaxy. The calculations are carried out in the context of two different scenarios for the distribution of clumps in the Galaxy and their concentrations, which result in very different conclusions.Comment: 24 pages, 7 ps fig

A Limit on Primordial Small-Scale Magnetic Fields from CMB Distortions

Spatially varying primordial magnetic fields may be efficiently dissipated prior to the epoch of recombination due to the large viscosity of the baryon-photon fluid. We show that this dissipation may result in observable chemical potential mu and Compton y distortions in the cosmic microwave background radiation (CMB) spectrum. Current upper limits on mu and y from FIRAS constrain magnetic fields to have strength B_0 < 3\times 10^{-8}Gauss (scaled to the present) between comoving coherence length \approx 400 pc and \approx 0.6 Mpc. This represents the strongest upper limit on small-scale primordial magnetic fields to date.Comment: 5 pages, accepted by Physical Review Letter