Targeted free energy perturbation

A generalization of the free energy perturbation identity is derived, and a computational strategy based on this result is presented. A simple example illustrates the efficiency gains that can be achieved with this method.Comment: 8 pages + 1 color figur

A new genus of Cophomantini, with comments on the taxonomic status of Boana liliae (Anura: Hylidae)

© 2018 The Linnean Society of London The non-monophyly of both the genus Myersiohyla and the Boana punctata group has been recovered in a number of published phylogenetic analyses. In this paper we report on the analysis of sequences of Boana liliae, a species originally assigned to the B. punctata group, in a dataset of Cophomantini that recovered novel phylogenetic relationships for this hylid tribe. Our results reveal Myersiohyla to be paraphyletic with respect to B. liliae. Support for the placement of Myersiohyla kanaima is poor, but this taxon is recovered as the sister taxon of the other Cophomantini genera (excluding Myersiohyla) or as the sister taxon of the remaining species of Myersiohyla (including B. liliae). These results lead us to propose two taxonomic changes in order to remedy the paraphyly of Myersiohyla: (1) a new genus is described for M. kanaima, and (2) Boana liliae is transferred to Myersiohyla. We further provide notes on the natural history and vocalizations of the new monotypic genus, a new diagnosis of the former B. liliae in the context of Myersiohyla, and discuss the evolution of tadpole morphology and biogeography of the earlier diverging clades of Cophomantini

Understanding person acquisition using an interactive activation and competition network

Face perception is one of the most developed visual skills that humans display, and recent work has attempted to examine the mechanisms involved in face perception through noting how neural networks achieve the same performance. The purpose of the present paper is to extend this approach to look not just at human face recognition, but also at human face acquisition. Experiment 1 presents empirical data to describe the acquisition over time of appropriate representations for newly encountered faces. These results are compared with those of Simulation 1, in which a modified IAC network capable of modelling the acquisition process is generated. Experiment 2 and Simulation 2 explore the mechanisms of learning further, and it is demonstrated that the acquisition of a set of associated new facts is easier than the acquisition of individual facts in isolation of one another. This is explained in terms of the advantage gained from additional inputs and mutual reinforcement of developing links within an interactive neural network system. <br/

'An outsider in our midst': narratives of Neil Lennon, soccer and ethno-religious igotry in the Scottish press

This essay offers a critique of media narratives concerning soccer and those of 'difference' in contemporary Scotland, in particular those who have Irishness as their different identity. It examines certain newspaper narratives concerning Neil Lennon of Celtic FC during autumn 2005. During this period Lennon was characterized as a soccer villain. The commentaries drew on existing perceptions concerning his personality and style of play. More importantly Lennon's national identity (Irish) and his religious background (Catholic) were integrated into the narratives, marking him as an outsider in Scotland. These narratives resonate with public and private discourses of 'otherness' concerning the Irish Catholic diaspora community in Scotland. These broader discourses are manifest as ethno-religious prejudices directed against this community. The discourses of 'outsider' and 'otherness' that surround Lennon, Celtic FC and the Irish Catholic community expose the myth of Scotland's collective self-image as an egalitarian and inclusive society

Magnitude and Kinetics of CD8+ T Cell Activation during Hyperacute HIV Infection Impact Viral Set Point

CD8[superscript +] T cells contribute to the control of HIV, but it is not clear whether initial immune responses modulate the viral set point. We screened high-risk uninfected women twice a week for plasma HIV RNA and identified 12 hyperacute infections. Onset of viremia elicited a massive HIV-specific CD8[superscript +] T cell response, with limited bystander activation of non-HIV memory CD8[superscript +] T cells. HIV-specific CD8[superscript +] T cells secreted little interferon-γ, underwent rapid apoptosis, and failed to upregulate the interleukin-7 receptor, known to be important for T cell survival. The rapidity to peak CD8[superscript +] T cell activation and the absolute magnitude of activation induced by the exponential rise in viremia were inversely correlated with set point viremia. These data indicate that rapid, high magnitude HIV-induced CD8[superscript +] T cell responses are crucial for subsequent immune control of acute infection, which has important implications for HIV vaccine design.Bill & Melinda Gates FoundationCollaboration for AIDS Vaccine DiscoveryWitten Family FoundationDan and Marjorie SullivanUrsula BrunnerGary and Loren CohenMark and Lisa Schwartz Foundation,International AIDS Vaccine Initiative (UKZNRSA1001)National Institute of Allergy and Infectious Diseases (U.S.) (R37AI067073)Center for AIDS Research (P30 AI060354

Cosmological parameters from SDSS and WMAP

We measure cosmological parameters using the three-dimensional power spectrum P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in combination with WMAP and other data. Our results are consistent with a ``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt, tensor modes or massive neutrinos. Adding SDSS information more than halves the WMAP-only error bars on some parameters, tightening 1 sigma constraints on the Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when dropping prior assumptions about curvature, neutrinos, tensor modes and the equation of state. Our results are in substantial agreement with the joint analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive consistency check with independent redshift survey data and analysis techniques. In this paper, we place particular emphasis on clarifying the physical origin of the constraints, i.e., what we do and do not know when using different data sets and prior assumptions. For instance, dropping the assumption that space is perfectly flat, the WMAP-only constraint on the measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running tilt, neutrino mass and equation of state in the list of free parameters, many constraints are still quite weak, but future cosmological measurements from SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt figures available at http://www.hep.upenn.edu/~max/sdsspars.htm

Why has research in face recognition progressed so slowly? The importance of variability

Despite many years of research, there has been surprisingly little progress in our understanding of how faces are identified. Here I argue that there are two contributory factors: (a) Our methods have obscured a critical aspect of the problem, within-person variability; and (b) research has tended to conflate familiar and unfamiliar face processing. Examples of procedures for studying variability are given, and a case is made for studying real faces, of the type people recognize every day. I argue that face recognition (specifically identification) may only be understood by adopting new techniques that acknowledge statistical patterns in the visual environment. As a consequence, some of our current methods will need to be abandoned