Blood diamonds: an analysis of the state of affairs and the effectiveness of the Kimberley Process

In an era when corporate responsibility and sustainability are gaining momentum, and growing access to information and communication has empowered consumers to make more socially responsible purchasing decisions, the diamond industry remains opaque. The Kimberley Process was established to monitor the rough diamond trade with the objective of stemming the flow of conflict diamonds. The definition of conflict diamonds, however, often excludes human rights abuses, which has led to mounting criticism. The purpose of this paper is to examine the prevalence, magnitude, and scope of ethical issues affecting sourcing conditions in the diamond industry. The research found that ethical issues were reported in the diamond industries of several African nations, with Angola topping the list. Child labour and slavery are the most prevalent human rights abuses. In 2017, one in five diamonds in terms of volume and one in ten diamonds in terms of value may have been produced under conditions that cannot be regarded as sustainable or ethical

Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs

We show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and cosmic microwave background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, and scenarios for light and heavy sterile neutrinos.Comment: 29 pages, 10 figure

Characterization of qubit chains by Feynman probes

We address the characterization of qubit chains and assess the performances of local measurements compared to those provided by Feynman probes, i.e. nonlocal measurements realized by coupling a single qubit regis- ter to the chain. We show that local measurements are suitable to estimate small values of the coupling and that a Bayesian strategy may be successfully exploited to achieve optimal precision. For larger values of the coupling Bayesian local strategies do not lead to a consistent estimate. In this regime, Feynman probes may be exploited to build a consistent Bayesian estimator that saturates the Cram\'er-Rao bound, thus providing an effective characterization of the chain. Finally, we show that ultimate bounds to precision, i.e. saturation of the quantum Cram\'er-Rao bound, may be achieved by a two-step scheme employing Feynman probes followed by local measurements.Comment: 8 pages, 5 figure

Dynamics of quantum correlations in colored environments

We address the dynamics of entanglement and quantum discord for two non interacting qubits initially prepared in a maximally entangled state and then subjected to a classical colored noise, i.e. coupled with an external environment characterized by a noise spectrum of the form $1/f^{\alpha}$. More specifically, we address systems where the Gaussian approximation fails, i.e. the sole knowledge of the spectrum is not enough to determine the dynamics of quantum correlations. We thus investigate the dynamics for two different configurations of the environment: in the first case the noise spectrum is due to the interaction of each qubit with a single bistable fluctuator with an undetermined switching rate, whereas in the second case we consider a collection of classical fluctuators with fixed switching rates. In both cases we found analytical expressions for the time dependence of entanglement and quantum discord, which may be also extended to a collection of flcutuators with random switching rates. The environmental noise is introduced by means of stochastic time-dependent terms in the Hamiltonian and this allows us to describe the effects of both separate and common environments. We show that the non-Gaussian character of the noise may lead to significant effects, e.g. environments with the same power spectrum, but different configurations, give raise to opposite behavior for the quantum correlations. In particular, depending on the characteristics of the environmental noise considered, both entanglement and discord display either a monotonic decay or the phenomena of sudden death and revivals. Our results show that the microscopic structure of environment, besides its noise spectrum, is relevant for the dynamics of quantum correlations, and may be a valid starting point for the engineering of non-Gaussian colored environments.Comment: 8 pages, 3 figure

Superspace formulation of general massive gauge theories and geometric interpretation of mass-dependent BRST symmetries

A superspace formulation is proposed for the osp(1,2)-covariant Lagrangian quantization of general massive gauge theories. The superalgebra os0(1,2) is considered as subalgebra of sl(1,2); the latter may be considered as the algebra of generators of the conformal group in a superspace with two anticommuting coordinates. The mass-dependent (anti)BRST symmetries of proper solutions of the quantum master equations in the osp(1,2)-covariant formalism are realized in that superspace as invariance under translations combined with mass-dependent special conformal transformations. The Sp(2) symmetry - in particular the ghost number conservation - and the "new ghost number" conservation are realized as invariance under symplectic rotations and dilatations, respectively. The transformations of the gauge fields - and of the full set of necessarily required (anti)ghost and auxiliary fields - under the superalgebra sl(1,2) are determined both for irreducible and first-stage reducible theories with closed gauge algebra.Comment: 35 pages, AMSTEX, precision of reference

Blood diamonds and ethical consumerism: an empirical investigation

Although ethical consumerism has witnessed significant interest in recent years, most studies have focused on low-value, commoditized product categories such as food and beverage and apparel. Despite its significance, the research on ethical consumerism in luxury product segments such as diamonds is relatively scant. This formed the motivation of this study, which examined the ethical buying behavior of consumers and the moderating effects of their income levels in the diamond industry. Four hundred eightteen responses toa structured questionnaire were collected. The framework comprising of four constructs, namely ethically-minded consumer behavior, willingness to pay more, ethical concerns regarding country of origin of diamonds, and ethical buying behavior of diamonds was first validated, and then the hypothesized relationships between the constructs were assessed using structural equation modeling. Overall, ethically minded consumer behavior had a significant positive impact on willingness to pay more, ethical concerns regarding the country of origin of diamonds, and ethical buying of diamonds. Additionally, ethical concerns regarding country of origin positively influenced the ethical buying of diamonds, while the willingness to pay more had no significant impact on ethical diamond purchases. The multi-group moderation test results revealed that the income levels of buyers do affect the relationships between constructs. For instance, for the middle income group, generic ethically-minded consumer behavior did not translate into the ethical buying behavior of diamonds. The findings provide useful insights for practitioners and policy-makers regarding ethical consumerism in the diamond industry and help to highlight the issues facing the industry, such as its poor supply chain transparency, human rights abuses, child labor, money laundering, bribery and corruption, and environmental degradation from mining activities

Evaluating tourism community preferences

A short online survey of Kingman Arizona residents included two approaches for determining the relative importance of social, cultural, environmental, and economic attributes to community quality of life. A simple multiattribute choice approach gave noticeably different results from a standard independent attribute ranking approach and lead researchers to recommend socially oriented tourism development projects over economically oriented ones

Neutrino energy transport in weak decoupling and big bang nucleosynthesis

We calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multi-energy group Boltzmann neutrino energy transport scheme. The modular structure of our code provides the ability to dissect the relative contributions of each process responsible for evolving the dynamics of the early universe in the absence of neutrino flavor oscillations. Such an approach allows a detailed accounting of the evolution of the $\nu_e$, $\bar\nu_e$, $\nu_\mu$, $\bar\nu_\mu$, $\nu_\tau$, $\bar\nu_\tau$ energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. This calculation reveals nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions (e.g., electron-positron pair densities), with implications for: the phasing between scale factor and plasma temperature; the neutron-to-proton ratio; light-element abundance histories; and the cosmological parameter \neff. We find that our approach of following the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma results in changes in the computed value of the BBN deuterium yield. For example, for particular implementations of quantum corrections in plasma thermodynamics, our calculations show a $0.4\%$ increase in deuterium. These changes are potentially significant in the context of anticipated improvements in observational and nuclear physics uncertainties.Comment: 37 pages, 12 Figures, 6 Table