NMR quantum computation with indirectly coupled gates

An NMR realization of a two-qubit quantum gate which processes quantum information indirectly via couplings to a spectator qubit is presented in the context of the Deutsch-Jozsa algorithm. This enables a successful comprehensive NMR implementation of the Deutsch-Jozsa algorithm for functions with three argument bits and demonstrates a technique essential for multi-qubit quantum computation.Comment: 9 pages, 2 figures. 10 additional figures illustrating output spectr

Approaching work and learning indirectly

This paper approaches work and learning indirectly. It is part of a mixed method longitudinal study that looks at the articulation from Higher National (HN) to part time Higher Education (HE). Since 2003 the Open University in Scotland (OU) has been collecting quantitative and qualitative data on students who have HN qualifications. This paper looks at the experiences of those students and the central place of work in those journeys. The paper beings with a statistical overview. HN Students that come to the OU tend to be older, the majority are in employment, they tend to reside in more deprived areas, and are often motivated by career aspiration. Their HN qualifications tend to cluster around the applied subjects as do the subjects they chose with the OU (Engineering and Technology, Education, and Health and Social Care). The picture is of widening HE participation in applied subjects. The paper then looks at the interview data from the 2011-12 study. Choosing a vocational pathway is not always determined by exam results (some had HE entry qualifications), expectations and opportunities are important. Critical incidents at the end of school (births and deaths) were part of that narrative, as were family expectations around the “safe place” provided by vocational pathways, along with the sense that HE study was not for them. Overall participants narrated “bumpy” interrupted transitions between education and employment. Stories that emphasised social and structural barriers, personal autonomy, and stories that seemed to call into question how useful it is to talk about definite transitions between education and employment. The vocational focus of most HN study means it is normal to regard work as the natural place for learning. This focus on practice means participants think of competence as something that develops formally and informally at and through work after they “qualify”. Interviewees seemed to accept that there was no job or role for life. The paper also considers the motivations for engaging in HE study. For these students work remains the principal focus. Just like HN, part-time distance learning is considered a “safe place” as people can balance study and work. “Getting on” or “getting out” feature strongly. For example, participants found themselves in roles that required HE qualifications, and sought the security and “mobility” that aligning their experience with a qualification would bring. Many cited personal factors; they looked back to “missed opportunities” with regret. However, it became apparent that what starts as personal leads to reflections on career progression and change as studies progress. The paper concludes with some reflections on the ways that articulation between HN and part-time study widens participation in HE. For those in work it also destabilises notions of smooth or appropriate transitions, and questions the boundaries between the personal and the professional

VEGF is indirectly associated with NO production

Background? Increased levels of vascular endothelial growth factor (VEGF) have been observed in patients with metabolic syndrome (MetS). Nitric oxide (NO) formation is reduced in MetS, but its relationship to VEGF production remains poorly defined. We evaluated the association between VEGF/NO synthesis and insulin sensitivity in obese subjects and investigated the secretory response of VEGF to an acute elevation of glucose.Materials and methods? Seven healthy normal-weight subjects, seven obese subjects without MetS and seven obese subjects with MetS were recruited. Anthropometry, body composition and cardiometabolic functions (blood pressure, glucose, insulin, triglycerides, total cholesterol, HDL-C and VEGF) were measured, and a novel stable isotope method was used to assess in vivo rates of NO production. A frequent sampling intravenous glucose tolerance test was performed to study the dynamics of VEGF release.Results? Fasting VEGF levels were significantly higher in the two obese groups compared to the control group (P for trend = 0·02), but the difference was not significant after adjustment for age. Vascular endothelial growth factor levels were associated with systolic blood pressure (? = 0·54; P = 0·01) and NO production (? = ?0·44; P = 0·04). Vascular endothelial growth factor levels increased in response to acute hyperglycaemia in normal-weight and obese subjects (P < 0·001).Conclusions? Vascular endothelial growth factor levels rapidly increase during hyperglycaemia and are inversely related to NO production at steady state. The potential link between the acute secretion of VEGF and atherosclerotic risk in subjects with poorly controlled glycaemia as well as the potential of lowering elevated VEGF levels by increasing NO production and/or availability warrants further investigation

Time-optimal CNOT between indirectly coupled qubits in a linear Ising chain

We give analytical solutions for the time-optimal synthesis of entangling gates between indirectly coupled qubits 1 and 3 in a linear spin chain of three qubits subject to an Ising Hamiltonian interaction with equal coupling $J$ plus a local magnetic field acting on the intermediate qubit. The energy available is fixed, but we relax the standard assumption of instantaneous unitary operations acting on single qubits. The time required for performing an entangling gate which is equivalent, modulo local unitary operations, to the $\mathrm{CNOT}(1, 3)$ between the indirectly coupled qubits 1 and 3 is $T=\sqrt{3/2} J^{-1}$, i.e. faster than a previous estimate based on a similar Hamiltonian and the assumption of local unitaries with zero time cost. Furthermore, performing a simple Walsh-Hadamard rotation in the Hlibert space of qubit 3 shows that the time-optimal synthesis of the $\mathrm{CNOT}^{\pm}(1, 3)$ (which acts as the identity when the control qubit 1 is in the state $\ket{0}$, while if the control qubit is in the state $\ket{1}$ the target qubit 3 is flipped as $\ket{\pm}\rightarrow \ket{\mp}$) also requires the same time $T$.Comment: 9 pages; minor modification

Indirectly Free Actions, Libertarianism, and Resultant Moral Luck

Martin Luther affirms his theological position by saying “Here I stand. I can do no other.” Supposing that Luther’s claim is true, he lacks alternative possibilities at the moment of choice. Even so, many libertarians have the intuition that he is morally responsible for his action. One way to make sense of this intuition is to assert that Luther’s action is indirectly free, because his action inherits its freedom and moral responsibility from earlier actions when he had alternative possibilities and those earlier directly free actions formed him into the kind of person who must refrain from recanting. Surprisingly, libertarians have not developed a full account of indirectly free actions. I provide a more developed account. First, I explain the metaphysical nature of indirectly free actions such as Luther’s. Second, I examine the kind of metaphysical and epistemic connections that must occur between past directly free actions and the indirectly free action. Third, I argue that an attractive way to understand the kind of derivative moral responsibility at issue involves affirming the existence of resultant moral luck

Ownership and control in a competitive industry

We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry profits are maximized within a symmetric two product monopoly, the investor attains this only in exceptional cases. Instead, she sometimes acquires a noncontrolling stake. Or she invests asymmetrically rather than pursuing a full takeover if she acquires a controlling one. Generally, she invests indirectly if she only wants to affect the product market outcome, and directly if acquiring shares is profitable per se. --differentiated products,separation of ownership and control,private benefits of control