Let the consumer decide? The regulation of commercial genetic testing.

Objectives—The development of predictive genetic tests provides a new area where consumers can gain knowledge of their health status and commercial opportunities. "Over-the-counter" or mail order genetic tests are most likely to provide information on carrier status or the risk of developing a multifactorial disease. The paper considers the social and ethical implications of individuals purchasing genetic tests and whether genetic information is different from other types of health information which individuals can obtain for themselves. Design—The discussion is illustrated by findings from a questionnaire survey of university students as potential consumers. Topics covered included what health tests they had already used, expectations of genetic tests, willingness to pay, who should have access to the results and whether there need to be restrictions on such tests. Sample—Six hundred and fifteen first-year students in the universities of Leuven, Cardiff, Central Lancashire, Vienna and Nijmegen studying either medicine or a non-science subject. Results—Students were enthusiastic about genetic tests and had high expectations of their accuracy and usefulness but most thought they should be available through the health service and a minority thought that some tests, for example for sex selection, should not be available at all. There were few differences in responses by sex or subject of study but some by country. The paper also considers ethical and social issues outside the scope of a questionnaire survey of this type. Conclusion—To address some of these issues the sale of genetic tests to individuals can be made subject to ethical guidelines or codes of practice, for example to protect vulnerable groups, but there are fundamental social and ethical questions which such guidelines cannot address

Some major impacts of the national space program. 3 - Astronomy as an example of scientific impacts

Impact of space exploration on astronomy and human cultur

An optimised scalable synthesis of H2O@C60and a new synthesis of H2@C60

New high-yielding synthetic routes to the small-molecule endofullerenes H2O@C60, D2O@C60 and H2@C60 are described. The use of high temperatures and pressures for the endohedral molecule incorporation are avoided. A new partial closure step using PPh3, and final suturing using a novel Diels–Alder/retro-Diels–Alder sequence are amongst the advances reported

Tree-irreducible automorphisms of free groups

We introduce a new class of automorphisms $\varphi$ of the non-abelian free group $F_N$ of finite rank $N \geq 2$ which contains all iwips (= fully irreducible automorphisms), but also any automorphism induced by a pseudo-Anosov homeomorphism of a surface with arbitrary many boundary components. More generally, there may be subgroups of $F_N$ of rank $\geq 2$ on which $\varphi$ restricts to the identity. We prove some basic facts about such {\em tree-irreducible} automorphisms, and show that, together with Dehn twist automorphisms, they are the natural basic building blocks from which any automorphism of \FN can be constructed in a train track set-up. We then show: {\bf Theorem:} {\it Every tree-irreducible automorphism of $F_N$ has induced North-South dynamics on the Thurston compactification $\bar{\rm CV}_N$ of Outer space.} Finally, we define a "blow-up" construction on the vertices of a train track map, which, starting from iwips, produces tree-irreducible automorphisms which in general are not iwip

Congressional Distributive Politics and State Economic Performance

This paper tests several theories of the effects of congressional representation on state economic growth. States that were represented by very senior Democratic congressmen grew more quickly during the 1953-1990 period than states that were represented by more junior congressional delegations. We find some, but weaker, evidence that states with a high fraction of their delegation on particularly influential committees also exhibit above-average growth. We also test partisan models of distributive politics by studying the relationship between a state's degree of political competition and its growth rate. Our findings support both nonpartisan and partisan models of congressional distributive politics. In spite of our findings with respect to economic growth, we can not detect any substantively important association between congressional delegation seniority, the degree of state political competition, and the geographic distribution of federal funds. The source of the growth relationships we identify therefore remains an open question.

Magic composite pulses

I describe composite pulses during which the average dipolar interactions within a spin ensemble are controlled while realizing a global rotation. The construction method used is based on the average Hamiltonian theory and rely on the geometrical properties of the spin-spin dipolar interaction only. I present several such composite pulses robust against standard experimental defects in NRM: static or radio-frequency field miscalibration, fields inhomogeneities. Numerical simulations show that the magic sandwich pulse sequence, a pulse sequence that reverse the average dipolar field while applied, is plagued by defects originating from its short initial and final \pi/2 radio-frequency pulses. Using the magic composite pulses instead of \pi/2 pulses improves the magic sandwich effect. A numerical test using a classical description of NMR allows to check the validity of the magic composite pulses and estimate their efficiency.Comment: 22 pages, 6 figure

Non-Markovian entanglement dynamics in the presence of system-bath coherence

A complete treatment of the entanglement of two-level systems, which evolves through the contact with a thermal bath, must include the fact that the system and the bath are not fully separable. Therefore, quantum coherent superpositions of system and bath states, which are almost never fully included in theoretical models, are invariably present when an entangled state is prepared experimentally. We show their importance for the time evolution of the entanglement of two qubits coupled to independent baths. In addition, our treatment is able to handle slow and low-temperature thermal baths.Comment: Accepted for publication in Phys. Rev. Lett

Robust dynamical decoupling

Quantum computers, which process information encoded in quantum mechanical systems, hold the potential to solve some of the hardest computational problems. A substantial obstacle for the further development of quantum computers is the fact that the life time of quantum information is usually too short to allow practical computation. A promising method to increase the life time, known as dynamical decoupling, consists of applying a periodic series of inversion pulses to the quantum bits. In the present review, we give an overview of this technique and compare different pulse sequences proposed earlier. We show that pulse imperfections, which are always present in experimental implementations, limit the performance of dynamical decoupling. The loss of coherence due to the accumulation of pulse errors can even exceed the perturbation from the environment. This effect can be largely eliminated by a judicious design of pulses and sequences. The corresponding sequences are largely immune to pulse imperfections and provide an increase of the coherence time of the system by several orders of magnitude