Achievable efficiencies for probabilistically cloning the states

We present an example of quantum computational tasks whose performance is enhanced if we distribute quantum information using quantum cloning. Furthermore we give achievable efficiencies for probabilistic cloning the quantum states used in implemented tasks for which cloning provides some enhancement in performance.Comment: 9 pages, 8 figure

Neutrino oscillations: Quantum mechanics vs. quantum field theory

A consistent description of neutrino oscillations requires either the quantum-mechanical (QM) wave packet approach or a quantum field theoretic (QFT) treatment. We compare these two approaches to neutrino oscillations and discuss the correspondence between them. In particular, we derive expressions for the QM neutrino wave packets from QFT and relate the free parameters of the QM framework, in particular the effective momentum uncertainty of the neutrino state, to the more fundamental parameters of the QFT approach. We include in our discussion the possibilities that some of the neutrino's interaction partners are not detected, that the neutrino is produced in the decay of an unstable parent particle, and that the overlap of the wave packets of the particles involved in the neutrino production (or detection) process is not maximal. Finally, we demonstrate how the properly normalized oscillation probabilities can be obtained in the QFT framework without an ad hoc normalization procedure employed in the QM approach.Comment: LaTeX, 42 pages, 1 figure; v2: minor clarifications, matches published version; v3: Corrected the discussion of the conditions under which an oscillation probability can be sensibly defined in the QFT approach (sec. 5.2.4

Quantum field theoretic approach to neutrino oscillations in matter

We consider neutrino oscillations in non-uniform matter in a quantum field theoretic (QFT) approach, in which neutrino production, propagation and detection are considered as a single process. We find the conditions under which the oscillation probability can be sensibly defined and demonstrate how the properly normalized oscillation probability can be obtained in the QFT framework. We derive the evolution equation for the oscillation amplitude and discuss the conditions under which it reduces to the standard Schr\"odinger-like evolution equation. It is shown that, contrary to the common usage, the Schr\"odinger-like evolution equation is not applicable in certain cases, such as oscillations of neutrinos produced in decays of free pions provided that sterile neutrinos with $\Delta m^2\gtrsim 1$ eV$^2$ exist.Comment: LaTeX, 24 pages + 16 pages of appendices, 1 figure. V2: typos correcte

Contraceptive Knowledge, Beliefs and Attitudes in Rural Malawi: Misinformation, Misbeliefs and Misperceptions

IntroductionThe objective of the study was to find out factors that affect the intentions of men and women to use family planning methods.MethodsThe study was conducted in Mangochi district, the southern regionof Malawi in 2006. About 60 Focus group discussions were conducted to identify the attitudes and beliefs of 30 male and 30 female participantsregarding family planning methods. The data was then transcribed and analyzed manually identifying central themes and relationships across the cases and narratives.ResultsMost of the respondents knew the different types of family planning methods and reported that health facilities had adequate stock of family planning supplies. However, it was found that most of the women and men were not using any modern family planning methods. Reasons included: family planning methods were perceived side effects, such as prolonged menstruation, men’s concerns about impotence and genital sores, weight gain or loss, and subsequent infertility. Traditional family planning methods were mostly used for infertility problems.ConclusionDespite knowing about the different types of family planning methods, and awareness of their ready availability in health facilities, use of these methods is low because considerable misinformation still prevails regarding contraceptive methods’ side effects

An action principle for the quantization of parametric theories and nonlinear quantum cosmology

By parametrizing the action integral for the standard Schrodinger equation we present a derivation of the recently proposed method for quantizing a parametrized theory. The reformulation suggests a natural extension from conventional to nonlinear quantum mechanics. This generalization enables a unitary description of the quantum evolution for a broad class of constrained Hamiltonian systems with a nonlinear kinematic structure. In particular, the new theory is applicable to the quantization of cosmological models where a chosen gravitational degree of freedom acts as geometric time. This is demonstrated explicitly using three cosmological models: the Friedmann universe with a massless scalar field and Bianchi type I and IX models. Based on these investigations, the prospect of further developing the proposed quantization scheme in the context of quantum gravity is discussed.Comment: 14 page

Towards designing robust coupled networks

Natural and technological interdependent systems have been shown to be highly vulnerable due to cascading failures and an abrupt collapse of global connectivity under initial failure. Mitigating the risk by partial disconnection endangers their functionality. Here we propose a systematic strategy of selecting a minimum number of autonomous nodes that guarantee a smooth transition in robustness. Our method which is based on betweenness is tested on various examples including the famous 2003 electrical blackout of Italy. We show that, with this strategy, the necessary number of autonomous nodes can be reduced by a factor of five compared to a random choice. We also find that the transition to abrupt collapse follows tricritical scaling characterized by a set of exponents which is independent on the protection strategy

Area Regge Calculus and Discontinuous Metrics

Taking the triangle areas as independent variables in the theory of Regge calculus can lead to ambiguities in the edge lengths, which can be interpreted as discontinuities in the metric. We construct solutions to area Regge calculus using a triangulated lattice and find that on a spacelike hypersurface no such discontinuity can arise. On a null hypersurface however, we can have such a situation and the resulting metric can be interpreted as a so-called refractive wave.Comment: 18 pages, 1 figur

Diversity and immune boosting claims of some African indigenous leafy vegetables in western Kenya

A survey was carried out to document the diversity and immune boosting claims of African indigenous leafy vegetables (AILVs) in Western Kenya. Both qualitative and quantitative methods of data collection were used. The results showed that there is diversity of AILVs in the study area with nine popular and frequently consumed, but cassava leaves, stinging nettle and russian comfry are not popular. Seven of these are cultivated but two, stinging nettle (Urtica massaica) and vine spinach (Basella alba) grow wildly. The AILVs are cultivated at subsistence level on home gardens withminimal inputs and only excess of this is sold. The religion one belonged to was significant (p<0.05) in determining consumption or not of some of the vegetables. The vegetables are rain fed and the process of harvesting is by first uprooting during thinning followed by breaking the main stem and finally plucking off the leaves with maturity. Vegetable preparation in most households was mainly by women. The elderly women were keen in this process and spent more time in preparing the vegetables which were believed to be ‘nutritious’. There was no processing and preservation of the AILVs for use during the dry season. The communities rely on wild weeds during such seasons. The AILVs though consumed for good nutrition are also associated with various medicinal and immune boosting claims. Out of the nine, five are known for various health benefits, African  nightshade and spider plant for good nutrition by 31.8% and 25.1% of the respondents, respectively, slender leaf for healing power by 34%, cowpea leaves and slender leaf for anti-aging by 50% and 43.8%, respectively, and cowpea leaves (43.6%) and amaranthus (53%) for smooth skin and adding blood, respectively. Chi square analysis indicated that African nightshade, spider plant and amaranthus are statistically significant (p<0.05) incontributing to good nutrition, healthy functioning of the body and immune boosting. Further analysis showed that spider plant and amaranthus are significant (p<0.05) for immune boosting.Key words: indigenous vegetables, diversity, immune boostin

Review of “The Archaeology of Andean Pastoralism” edited by José M. Capriles and Nicholas

Book details Capriles J M and Tripcevich N (eds.) The Archaeology of Andean Pastoralism Albuquerque: University of New Mexico Press; 2016. 280 pages, 87 figures, 25 tables ISBN 978-0-8263-5702-