Recognising the ageing face: the role of age in face processing

The effects of age-induced changes on face recognition were investigated as a means of exploring the role of age in the encoding of new facial memories. The ability of participants to recognise each of six previously learnt faces was tested with versions which were either identical to the learnt faces, the same age (but different in pose and expression), or younger or older in age. Participants were able to cope well with facial changes induced by ageing: their performance with older, but not younger, versions was comparable to that with faces which differed only in pose and expression. Since the large majority of different age versions were recognised successfully, it can be concluded that the process of recognition does not require an exact match in age characteristics between the stored representation of a face and the face currently in view. As the age-related changes explored here were those that occur during the period of growth, this in turn implies that the underlying structural physical properties of the face are (in addition to pose and facial expression) invariant to a certain extent

Factors influencing the accuracy of age-estimates of unfamiliar faces

Factors affecting the accuracy with which adults could assess the age of unfamiliar male faces aged between 5 and 70 years were examined. In the first experiment twenty-five 'young' adult subjects, aged 16-25, and twenty-five 'old' adults, aged 51-60, were used. Each subject saw five versions of three different faces: these consisted of an original version of each face and four manipulated versions of it. The manipulations consisted of mirror reversal, pseudo-cardioidal strain, thresholding, and elimination of all but the internal features of the face. The second experiment was similar except that a between-subjects design was used: each subject saw three faces for each age category of target face, but was exposed to only a single type of manipulation (plus a set of 'original' faces which were identical for all groups, so that the comparability of the different groups in age estimation could be checked). Results from both experiments were similar. Age estimates for unmanipulated 'original' faces were highly accurate, although subjects were most accurate with target faces that were within their own age range. Results for the manipulated faces implied that the importance of cardioidal strain as a necessary and sufficient cue to age may have been overestimated in previous reports: subjects' age estimates were accurate when cardioidal strain was absent from the stimulus, and poor when cardioidal strain was the only cue available

Measuring and testing for gender discrimination in professions: the case of English family doctors

In 2004 the income of female GPs was 70%, and their wages (income per hour) were 91%, of those of male GPs. We compare estimates of gender discrimination from Oaxaca decompositions using models of wages (income/hours), OLS and 2SLS models of income, and propensity score matching. We propose a new direct test for within workplace gender discrimination based on a comparison of the differences in income of female and male GPs in practices in which all GPs are of the same gender with the differences in male and female income in mixed gender practices. We find that the coefficients on log hours in the log income models are positive but significantly less than 1, so that log wage models are misspecified. Discrimination, as measured by the unexplained difference in mean log income varied between 21% to 28%. However, our direct tests could not reject the null hypothesis of no within workplace gender discrimination.Gender discrimination. Professions. Family doctors. Propensity score matching.

The impact of the London bombings on the well-being of adolescent Muslims

We exploit the timing of the London bombings, coinciding with a large‐scale national survey of adolescents, to identify the impact of extremist Islamic terror attacks on the well‐being of adolescent Muslims. Our analysis reveals interesting gender differences. We find evidence of a decline in the happiness of Muslim teenage girls after the bombings, which is also accompanied by a rise in expectations of facing discrimination in the labour market. These findings are robust to several falsification tests. On the other hand, we fail to uncover compelling evidence of any impact of the bombings on Muslim teenage boys

RNA interference screening reveals host CaMK4 as a regulator of cryptococcal uptake and pathogenesis

ABSTRACT Cryptococcus neoformans , the causative agent of cryptococcosis, is an opportunistic fungal pathogen that kills over 200,000 individuals annually. This yeast may grow freely in body fluids, but it also flourishes within host cells. Despite extensive research on cryptococcal pathogenesis, host genes involved in the initial engulfment of fungi and subsequent stages of infection are woefully understudied. To address this issue, we combined short interfering RNA silencing and a high-throughput imaging assay to identify host regulators that specifically influence cryptococcal uptake. Of 868 phosphatase and kinase genes assayed, we discovered 79 whose silencing significantly affected cryptococcal engulfment. For 25 of these, the effects were fungus specific, as opposed to general alterations in phagocytosis. Four members of this group significantly and specifically altered cryptococcal uptake; one of them encoded CaMK4, a calcium/calmodulin-dependent protein kinase. Pharmacological inhibition of CaMK4 recapitulated the observed defects in phagocytosis. Furthermore, mice deficient in CaMK4 showed increased survival compared to wild-type mice upon infection with C. neoformans . This increase in survival correlated with decreased expression of pattern recognition receptors on host phagocytes known to recognize C. neoformans . Altogether, we have identified a kinase that is involved in C. neoformans internalization by host cells and in host resistance to this deadly infection. </jats:p

Dynamics of nonlinear cross-equatorial flow in the deep ocean

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution December 1996The transformation of potential vorticity within and stability of nonlinear deep western boundary currents in an idealized tropical ocean are studied using a shallowwater model. Observational evidence indicates that the potential vorticity of fluid parcels in deep western boundary currents must change sign as they cross the equator, but this evidence is otherwise unable to clarify the process. A series of numerical experiments investigate this transformation in a rectangular basin straddling the equator. A mass source located in the northwestern corner feeds fluid into the domain where it is constrained to cross the equator to reach a distributed mass sink. Dissipation is included as momentum diffusion. The Reynolds number, defined as the ratio of the mass source per unit depth to the viscosity, determines the nature of the flow, and a critical value, Rec, divides its possible behavior into two regimes. For Re < Rec, the flow is laminar and well described by linear theory. For Re just above the critical value, the flow is time-dependent, with cyclonic eddies forming in the western boundary current near the equator. For still larger Reynolds number, eddies of both signs emerge and form a complicated, interacting network that extends into the basin several deformation radii from the western boundary, as well as north and south of the equator. The eddy field is established as the mechanism for potential vorticity transformation in nonlinear cross-equatorial flow. The analysis of vorticity fluxes follows from the flux-conservative form of the absolute vorticity equation. It is shown that the zonally integrated meridional flux of vorticity across the equator using no slip boundary conditions is virtually zero even in the strongly nonlinear limit suggesting that the eddies are extremely efficient vorticity transfer agents. A decomposition of the vorticity fluxes into components due to mean advection, eddy transport, and friction, reveals the growth with Reynolds number of a turbulent boundary layer that exchanges vorticity between the inertial portion of the boundary current and a frictional sub-layer where modification is straightforward. A linear stability analysis of the shallow-water system in the tropical ocean examines the initial formation of the eddy field. The formulation assumes that the basic state is purely meridional and on a local f-plane. Realistic western boundary current profiles undergo a horizontal shear instability that is partially stabilized by viscosity. Calculations at several latitudes indicate that the instability is enhanced in the tropics where the internal deformation radius is a maximum. The linear stability analysis predicts a length scale of the disturbance, a location for its origin, and a critical Reynolds number that agree well with numerical results.Financial support for this research was provided by NSF grant number OCE- 9115915 and ONR ASSERT grant number N00014-94-1-0844