Decoding face categories in diagnostic subregions of primary visual cortex

Higher visual areas in the occipitotemporal cortex contain discrete regions for face processing, but it remains unclear if V1 is modulated by top-down influences during face discrimination, and if this is widespread throughout V1 or localized to retinotopic regions processing task-relevant facial features. Employing functional magnetic resonance imaging (fMRI), we mapped the cortical representation of two feature locations that modulate higher visual areas during categorical judgements – the eyes and mouth. Subjects were presented with happy and fearful faces, and we measured the fMRI signal of V1 regions processing the eyes and mouth whilst subjects engaged in gender and expression categorization tasks. In a univariate analysis, we used a region-of-interest-based general linear model approach to reveal changes in activation within these regions as a function of task. We then trained a linear pattern classifier to classify facial expression or gender on the basis of V1 data from ‘eye’ and ‘mouth’ regions, and from the remaining non-diagnostic V1 region. Using multivariate techniques, we show that V1 activity discriminates face categories both in local ‘diagnostic’ and widespread ‘non-diagnostic’ cortical subregions. This indicates that V1 might receive the processed outcome of complex facial feature analysis from other cortical (i.e. fusiform face area, occipital face area) or subcortical areas (amygdala)

Experiments in the automatic marking of ER-Diagrams

In this paper we present an approach to the computer understanding of diagrams and show how it can be successfully applied to the automatic marking (grading) of student attempts at drawing entity-relationship (ER) diagrams. The automatic marker has been incorporated into a revision tool to enable students to practice diagramming and obtain feedback on their attempts

Using patterns in the automatic marking of ER-Diagrams

This paper illustrates how the notion of pattern can be used in the automatic analysis and synthesis of diagrams, applied particularly to the automatic marking of ER-diagrams. The paper describes how diagram patterns fit into a general framework for diagram interpretation and provides examples of how patterns can be exploited in other fields. Diagram patterns are defined and specified within the area of ER-diagrams. The paper also shows how patterns are being exploited in a revision tool for understanding ER-diagrams

Comment on "New Experimental Limit for the Electric Dipole Moment of the Neutron"

A new limit for the neutron electric dipole moment has been recently reported. This new limit is obtained by combining the result from a previous experiment with the result from a more recent experiment that has much worse statistical accuracy. We show that the old result has a systematic error possibly four times greater than the new limit, and under the circumstances, averaging of the old and new results is statistically invalid. The conclusion is that it would be more appropriate to quote two independent but mutually supportive limits as obtained from each experiment separately.Comment: 7 pages, 2 figure

A study of fluidised bed granulation

An experimental study of fluisised bed granulation is presented. Preliminary experiments establish the main variables in the granulation process and enable a systematic experimental programme to be devised. In this programme, either glass powder or porous alumina are used as the bed material. The effects of the fundamental fluidised bed granulation parameters on particle growth are established from a series of batch experiments conducted in a 0.15m diameter, glass-walled bed. Together with measurements of the physical properties of the product granules and the binder solutions (carbowax or benzoic acid, in methanol) and with supporting studies of the bed structure (in the form of X-ray photography and measurement of temperature profiles), this information is also used to propose a mechanism of particle growth. Two types of product granule are identified, agglomerates which consist of two or more, and usually several, initial particles; and layered granules, which consist of single initial particles with dried feed material adhering to the surface. The effects of varying the excess fluidising gas velocity, the binder concentration and the initial particle size are quantified. A bed can be prevented from quenching (a defluidisation phenomenon leading to the failure of the process) by increasing the fluidising gas rate. For a given bed particle/binder combination, successively higher excess gas velocities allow an otherwise quenching bed to be operated firstly so as to produce agglomerates and subsequently layered granules. Similar effects are observed with increases in initial bed particle size and decreases in binder concentration. A particle growth mechanism is proposed in which the initial stages of both the desirable particle growth (irrespective of the type of granule) and of bed quenching, are considered to be exactly the same. Beyond the initial formation of liquid bonds between adjacent bed particles, the strength of the inter-particle bridges (which is a function of the binder material and relates to growth) and the extent of fluid drag and inertial forces on particles (which are functions of gas velocity and particle size respectively, and relate to granule breakdown) determine the equilibrium granule form and size. However, if the particles are porous the above mechanism may break down since the liquid can enter the pores and not be available for the initial formation of liquid bonds

Corticosteroids for treating nerve damage in leprosy. A Cochrane review.

OBJECTIVE: Corticosteroids are commonly used for treating nerve damage in leprosy. We assessed the effectiveness of corticosteroids for treating nerve damage due to leprosy. METHODS: A systematic search was undertaken to identify randomised controlled trials (RCTs) comparing corticosteroids with placebo or with no treatment. Two authors independently assessed quality and extracted data. Where it was not possible to perform a meta-analysis, the data for each trial was summarised. RESULTS: Three RCTs involving 513 people were found. Two trials compared prednisolone with placebo. One trial treated mild sensory impairment of less than 6 months duration and the other trial treated nerve function impairment of 6 to 24 months duration. Both trials examined nerve function improvement 12 months from the start of treatment, but found no significant difference between the two groups. The third trial compared three corticosteroid regimens for severe type 1 reactions. After 12 months, a significantly higher proportion of individuals on a 3 month course required extra corticosteroids compared to the groups with a high-dose and low-dose regimen of 5 months duration. Diabetes and peptic or infected ulcers were not significantly more often reported in the corticosteroid compared to the placebo group. CONCLUSIONS: Evidence from RCTs does not show a significant long-term effect for either long-standing nerve function impairment or mild sensory impairment. A 5 month corticosteroid regimen was significantly more beneficial than a 3 month corticosteroid regimen. Further RCTs are needed to establish the effectiveness and optimal regimens of corticosteroids and to examine new therapies

Force-Extension Relations for Polymers with Sliding Links

Topological entanglements in polymers are mimicked by sliding rings (slip-links) which enforce pair contacts between monomers. We study the force-extension curve for linear polymers in which slip-links create additional loops of variable size. For a single loop in a phantom chain, we obtain exact expressions for the average end-to-end separation: The linear response to a small force is related to the properties of the unstressed chain, while for a large force the polymer backbone can be treated as a sequence of Pincus--de Gennes blobs, the constraint effecting only a single blob. Generalizing this picture, scaling arguments are used to include self-avoiding effects.Comment: 4 pages, 5 figures; accepted to Phys. Rev. E (Brief Report

Frequent activity on Vulcano (Italy) spanning the last 80 ky: New insights from the chemo-stratigraphy of the Brown Tuffs

The Brown Tuffs (BT) are widespread reddish-brown to grey, ash-rich pyroclastic deposits recognized in the stratigraphic sequences of the Aeolian Islands and Capo Millazzo peninsula (Sicily) that span the last 80 ky. They have very homogeneous lithological, textural and sedimentological features which make it difficult to reliably correlate units on the islands to proximal units in the source areas. Here we carefully re-interpret the stratigraphic profiles of the BT on Vulcano and Lipari where the deposits are thickest and present the most complete succession. The investigation is based on a large dataset of major and minor element geochemistry of juvenile glass components for the majority of the recognized BT depositional units, whilst also providing new radiocarbon ages. The distinctive chemical groupings observed within the glass analyses, both temporally and spatially, allow us to fingerprint the three main stratigraphically defined macro-units in which the BT succession can be sub-divided using prominent tephra marker beds, the Ischia Tephra (Monte Epomeo Green Tuff; 56 ky) and Monte Guardia pyroclastics from Lipari (herein radiocarbon dated to 27\u201326 ky). The Lower (80\u201356 ky; LBT), Intermediate (56\u201327 ky; IBT) and Upper BT (here dated at 24\u20136 ky; UBT) macro-units display K-series volcanic glasses ranging from basaltic trachy-andesites, through trachy-andesites, to more evolved trachytes, all consistent with an origin on Vulcano. The UBT are clearly distinguished from the lower macro units by their higher-SiO2 trachy-andesite to trachytic glasses, which extend to noticeably lower TiO2, CaO and MgO contents. These features make it possible to re-define the geochemical-evolutionary boundary between IBT and UBT as corresponding to the 24 ky Spiaggia Lunga scoria bed on Vulcano, which is stratigraphically higher (and younger) than the previous boundary marker (Monte Guardia). The glass compositions of the LBT, IBT and UBT are used to: (1) assess links to known proximal eruption units outcropping on Vulcano; (2) validate medial-distal BT occurrences across the Aeolian archipelago (Salina, Filicudi and Panarea) and on Capo Millazzo; (3) confirm that the BT are responsible for distal volcanic ash layers preserved in Central Mediterranean marine sedimentary archives. Interestingly, the glass compositions of the UBT are very similar to those of the Punte Nere unit, the earliest pyroclastic products erupted from the currently active La Fossa cone on Vulcano, indicating the corresponding magmatic system has likely erupted similar melts and products over the last 24 ky and thus extending its life cycle. Such information is crucial for evaluating the long-term eruption scenarios underpinning hazard assessment of the La Fossa caldera magmatic system

Characterisation of thermally poled silica glass using the laser-induced pressure pulse probe technique

A recent breakthrough in nonlinear optics of glass is the observation of high permanent second-order nonlinearities (SON) of the order of 1 pm/V in thermally poled fused silica glass and 0.2 pm/V in thermally poled optical fibres. Despite the plethora of poling techniques, the mechanism behind the formation of SON is not yet fully understood