Novel Cascaded Ultra Bright Pulsed Source of Polarization Entangled Photons

A new ultra bright pulsed source of polarization entangled photons has been realized using type-II phase matching in spontaneous parametric down conversion process in two cascaded crystals. The optical axes of the crystals are aligned in such a way that the extraordinarily (ordinarily) polarized cone from one crystal overlaps with the ordinarily (extraordinarily) polarized cone from the second crystal. This spatial overlapping removes the association between the polarization and the output angle of the photons that exist in a single type-II down conversion process. Hence, entanglement of photons originating from any point on the output cones is possible if a suitable optical delay line is used. This delay line is particularly simple and easy to implement.Comment: 8 pages 8 figure

Numerical study of the thermodynamics of clinoatacamite

We study the thermodynamic properties of the clinoatacamite compound, Cu_2(OH)_3Cl, by considering several approximate models. They include the Heisenberg model on (i) the uniform pyrochlore lattice, (ii) a very anisotropic pyrochlore lattice, and (iii) a kagome lattice weakly coupled to spins that sit on a triangular lattice. We utilize the exact diagonalization of small clusters with periodic boundary conditions and implement a numerical linked-cluster expansion approach for quantum lattice models with reduced symmetries, which allows us to solve model (iii) in the thermodynamic limit. We find a very good agreement between the experimental uniform susceptibility and the numerical results for models (ii) and (iii), which suggests a weak ferromagnetic coupling between the kagome and triangular layers in clinoatacamite. We also study thermodynamic properties in a geometrical transition between a planar pyrochlore lattice and the kagome lattice.Comment: 7 pages, 7 figure

Relative uptake of minoxidil into appendages and stratum corneum and permeation through human skin in vitro

We examined uptake of the model therapeutic agent, minoxidil, into appendages, stratum corneum (SC), and through human skin, under the influence of different vehicles. Quantitative estimation of therapeutic drug deposition into all three areas has not previously been reported. Finite doses of minoxidil (2%, w/v) in formulations containing varying amounts of ethanol, propylene glycol (PG), and water (60:20:20, 80:20:0, and 0:80:20 by volume, respectively) were used. Minoxidil in SC (by tape stripping), appendages (by cyanoacrylate casting), and receptor fluid was determined by liquid scintillation counting. At early times (30 min, 2 h), ethanol-containing formulations (60:20:20 and 80:20:0) caused significantly greater minoxidil retention in SC and appendages, compared to the formulation lacking ethanol (0:80:20). A significant increase in minoxidil receptor penetration occurred with the PG-rich 0:80:20 formulation after 12 h. We showed that deposition of minoxidil into appendages, SC, and skin penetration into receptor fluid were similar in magnitude. Transport by the appendageal route is likely to be a key determinant of hair growth promotion by minoxidil. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:712–718, 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64562/1/21856_ftp.pd

Investigating the timecourse of accessing conversational implicatures during incremental sentence interpretation

Many contextual inferences in utterance interpretation are explained as following from the nature of conversation and the assumption that participants are rational. Recent psycholinguistic research has focussed on certain of these ‘Gricean’ inferences and have revealed that comprehenders can access them in online interpretation. However there have been mixed results as to the time-course of access. Some results show that Gricean inferences can be accessed very rapidly, as rapidly as any other contextually specified information (Sedivy, 2003; Grodner, Klein, Carbery, & Tanenhaus, 2010); while other studies looking at the same kind of inference suggest that access to Gricean inferences are delayed relative to other aspects of semantic interpretation (Huang & Snedeker, 2009; in press). While previous timecourse research has focussed on Gricean inferences that support the online assignment of reference to definite expressions, the study reported here examines the timecourse of access to scalar implicatures, which enrich the meaning of an utterance beyond the semantic interpretation. Even if access to Gricean inference in support of reference assignment may be rapid, it is still unknown whether genuinely enriching scalar implicatures are delayed. Our results indicate that scalar implicatures are accessed as rapidly as other contextual inferences. The implications of our results are discussed in reference to the architecture of language comprehension

A brave new world: the new normal for general practice after the COVID-19 pandemic

General practice in the UK transformed almost overnight in March 2020 in response to the COVID-19 pandemic. Practices largely shut their doors, face-to-face consultations almost exclusively became remote consultations, research evidence was implemented within days of being published, and much routine work postponed and labelled ‘non-essential’. As we settle into this (temporary) new way of working, we have a unique opportunity to reflect on our old and new working practices and decide what we should continue, change, and stop doing. Specifically, we consider what this ‘new normal’ could be in terms of remote consulting, practice re-organisation, use and implementation of evidence, advanced care planning, patient behaviour and chronic disease management, and implications for future practice, research, and policy

The open future, bivalence and assertion

It is highly intuitive that the future is open and the past is closed—whereas it is unsettled whether there will be a fourth world war, it is settled that there was a first. Recently, it has become increasingly popular to claim that the intuitive openness of the future implies that contingent statements about the future, such as ‘there will be a sea battle tomorrow,’ are non-bivalent (neither true nor false). In this paper, we argue that the non-bivalence of future contingents is at odds with our pre-theoretic intuitions about the openness of the future. These are revealed by our pragmatic judgments concerning the correctness and incorrectness of assertions of future contingents. We argue that the pragmatic data together with a plausible account of assertion shows that in many cases we take future contingents to be true (or to be false), though we take the future to be open in relevant respects. It follows that appeals to intuition to support the non-bivalence of future contingents is untenable. Intuition favours bivalence

Violation of Bell's Inequality with Photons from Independent Sources

We report a violation of Bell's inequality using one photon from a parametric down-conversion source and a second photon from an attenuated laser beam. The two photons were entangled at a beam splitter using the post-selection technique of Shih and Alley [Phys. Rev. Lett. 61, 2921 (1988)]. A quantum interference pattern with a visibility of 91% was obtained using the photons from these independent sources, as compared with a visibility of 99.4% using two photons from a central parametric down-conversion source.Comment: 4 pages, 5 figures; minor change

Bell State Preparation using Pulsed Non-Degenerate Two-Photon Entanglement

We report a novel Bell state preparation experiment. High-purity Bell states are prepared by using femtosecond pulse pumped \emph{nondegenerate} collinear spontaneous parametric down-conversion. The use of femtosecond pump pulse {\em does not} result in reduction of quantum interference visibility in our scheme in which post-selection of amplitudes and other traditional mechanisms, such as, using thin nonlinear crystals or narrow-band spectral filters are not used. Another distinct feature of this scheme is that the pump, the signal, and the idler wavelengths are all distinguishable, which is very useful for quantum communications.Comment: 4 pages, submitted to PR

Illocutionary harm

A number of philosophers have become interested in the ways that individuals are subject to harm as the performers of illocutionary acts. This paper offers an account of the underlying structure of such harms: I argue that speakers are the subjects of illocutionary harm when there is interference in the entitlement structure of their linguistic activities. This interference comes in two forms: denial and incapacitation. In cases of denial, a speaker is prevented from achieving the outcomes to which they are entitled by their speech. In cases of incapacitation, a speaker’s standing to expect certain outcomes is itself undermined. I also discuss how individual speakers are subject to interference along two dimensions: as exercisers of certain non-linguistic capacities, and as producers of meaningful speech