Impaired processing of facial happiness, with or without awareness, in developmental prosopagnosia

Developmental prosopagnosia (DP) is associated with severe, lifelong deficits in face recognition, with such cases often cited as support for a dissociation between the processing of facial identity and emotion. Here we examine the evidence against this dissociation and propose that the processing of facial happiness, either with or without awareness, is actually integrated within the same neural network involved in facial identity recognition. We also test this hypothesis on a group of DP cases and neurotypical controls (NT) by adapting them to expressionless neutral faces, intact happy faces and hybrid faces. Despite these hybrid faces being explicitly identified as expressionless due to their higher spatial frequencies taken from a neutral face, their low spatial frequencies convey happy facial expressions that participants are unaware of. After adaptation, participants were asked to judge the facial expressions of face stimuli that were morphed incrementally in varying degrees of sad through to happy. Both groups exhibited emotion adaptation aftereffects to the intact happy faces, although this effect was smaller in DP. Whereas NT produced emotion adaptation aftereffects without awareness of the happy emotion in the hybrid faces; as a group, those with DP did not. Furthermore, our DP cases also exhibited deficits in judging the emotion of the happiest morphed test faces. Our results indicate that the processing of happy facial expressions, with or without awareness, is likely integrated within the face recognition network. We hypothesise that the previously identified abnormalities in the fusiform gyrus in those with DP is the most likely structure responsible for these deficits.MOE (Min. of Education, S’pore)Accepted versio

Unconventional superconductivity in La7Ir3 revealed by muon spin relaxation : introducing a new family of noncentrosymmetric superconductor that breaks time-reversal symmetry

The superconductivity of the noncentrosymmetric compound La7Ir3 has been investigated using muon spin rotation and relaxation (μSR). Zero-field measurements reveal the presence of spontaneous static or quasi-static magnetic fields below the superconducting transition temperature Tc = 2:25 K - a clear indication that the superconducting state breaks time-reversal symmetry. Furthermore, transverse-field rotation measurements suggest that the superconducting gap is isotropic, and that the pairing symmetry of the superconducting electrons is predominantly s-wave with an enhanced binding strength. The results indicate that the superconductivity in La7Ir3 may be unconventional, and paves the way for further studies of this family of materials

Ethnicity, voter alignment and political party affiliation - an African case: Zambia

Conventional wisdom holds that ethnicity provides the social cleavage for voting behav-iour and party affiliation in Africa. Because this is usually inferred from aggregate data of national election results, it might prove to be an ecological fallacy. The evidence based on individual data from an opinion survey in Zambia suggests that ethnicity matters for voter alignment and even more so for party affiliation, but it is certainly not the only factor. The analysis also points to a number of qualifications which are partly methodology-related. One is that the degree of ethnic voting can differ from one ethno-political group to the other depending on various degrees of ethnic mobilisation. Another is that if smaller eth-nic groups or subgroups do not identify with one particular party, it is difficult to find a significant statistical correlation between party affiliation and ethnicity - but that does not prove that they do not affiliate along ethnic lines.Wahlverhalten und Mitgliedschaft in politischen Parteien Afrikas ist nur wenig untersucht worden. Gewöhnlich wird argumentiert, dass Ethnizität als soziale Konfliktlinie das Wahlverhalten und die Parteienmitgliedschaft strukturiert. Da dieses Argument auf hoch aggregierten Wahldaten beruht, kann hier ein ökologischer Fehlschuss vorliegen. Die vorliegende Analyse beruht deshalb auf individuellen Umfragedaten aus Sambia. Das Ergebnis ist, dass Ethnizität tatsächlich eine Rolle für das Wahlverhalten und die Parteienmitgliedschaft spielt, aber keineswegs den einzigen Erklärungsfaktor darstellt. Die Analyse offenbart zudem eine Reihe von Einschränkungen und Qualifizierungen, die teilweise methodischer Natur sind. Eine ist, dass ethnisches Wahlverhalten und Parteienmitgliedschaft von einer ethnischen Gruppe zur anderen unterschiedlich ist, dass, wenn sich kleinere ethnische Gruppen oder Untergruppen mit keiner Partei identifizieren, es schwierig wird, statistisch signifikante Korrelationen zu finden - was indessen noch nicht beweist, dass Ethnizität keine Rolle spielt

Characterization of degeneration in the retina, brain and spinal cord of the Cln1 knockout mouse

Abstract only availableThe neuronal-ceroid lipofuscinoses (NCLs; often referred to as Battens Disease) are a group of hereditary disorders of childhood. Symptoms of NCLs are characterized by neurodegeneration with progressive neural cell death in the retina and central nervous system (CNS). The infantile form of NCL results from a deficiency in the protein, palmitoyl protein thioesterase-1 (PPT-1). PPT-1, encoded by the Cln1 gene, removes long chain fatty acids from modified cysteine residues in proteins. Mutations in the Cln1 gene are associated with an accumulation of autofluorescent lysosomal lipopigments in various tissues such as the retina and CNS. In the current study, we use a transgenic mouse model in which the gene for Cln1 has been mutated, i.e., 'knocked out'. Our goal is to perform histological experiments to assess the functional progression of neurodegenerative changes in the retina, brain and spinal cord as the subject ages. The retina, brain and spinal cord of the mice at different ages were fixed and embedded in plastic resin and/or paraffin. Thick sections (1 mm or 10 mm, respectively) were stained with toluidine blue or propidium iodide to detect neuronal loss and/or apoptosis as a result of the PPT-1 deficiency. Fluorescent images of the stained sections were obtained to document changes in tissue structure and the extent of degeneration. These studies provide information that will aid future studies in which stem cell transplants will be made into the Cln1 knockout mouse model. Ultimately, this approach will determine whether combined gene and stem cell therapies can be applied to patients with Battens Disease.Molecular Biology Progra

Superconducting and normal-state properties of the noncentrosymmetric superconductor Re3Ta

The noncentrosymmetric superconductor, Re3Ta, has been characterized in detail with a combination of magnetization, heat capacity, and electrical resistivity measurements, as well as a microscopic investigation of the internal magnetic fields using muon spin spectroscopy (μSR). In low applied fields, we observe 100% flux expulsion at a temperature of Tc = 4.68 K, which is concomitant with a sudden decrease of the electrical resistivity to zero and a sharp discontinuity in the heat capacity, confirming bulk superconductivity in this material. We find that Re3Ta is a poor metal, with superconductivity occurring in the dirty limit, and in which the disorder in the structure dominates the physical properties. Zero-field μSR shows that the superconducting state preserves time-reversal symmetry, and transverse-field measurements of the superfluid density are well described by an isotropic s-wave model. A careful analysis of the internal field distribution reveals a high level of disorder in the vortex lattice. Furthermore, we have combined the experimental data and calculated the effective mass, carrier density, and electronic mean-free path in this material, and ultimately show that Re3Ta lies close to the unconventional region of the Uemura plot

The large-scale Quasar-Lyman \alpha\ Forest Cross-Correlation from BOSS

We measure the large-scale cross-correlation of quasars with the Lyman \alpha\ forest absorption in redshift space, using ~ 60000 quasar spectra from Data Release 9 (DR9) of the Baryon Oscillation Spectroscopic Survey (BOSS). The cross-correlation is detected over a wide range of scales, up to comoving separations r of 80 Mpc/h. For r > 15 Mpc/h, we show that the cross-correlation is well fitted by the linear theory prediction for the mean overdensity around a quasar host halo in the standard \Lambda CDM model, with the redshift distortions indicative of gravitational evolution detected at high confidence. Using previous determinations of the Lyman \alpha\ forest bias factor obtained from the Lyman \alpha\ autocorrelation, we infer the quasar bias factor to be b_q = 3.64^+0.13_-0.15 at a mean redshift z=2.38, in agreement with previous measurements from the quasar auto-correlation. We also obtain a new estimate of the Lyman \alpha\ forest redshift distortion factor, \beta_F = 1.1 +/- 0.15, slightly larger than but consistent with the previous measurement from the Lyman \alpha\ forest autocorrelation. The simple linear model we use fails at separations r < 15 Mpc/h, and we show that this may reasonably be due to the enhanced ionization due to radiation from the quasars. We also provide the expected correction that the mass overdensity around the quasar implies for measurements of the ionizing radiation background from the line-of-sight proximity effect.Comment: 24 pages, 6 figures, published in JCA

Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season

© Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 License. Whitehead, J. D., Darbyshire, E., Brito, J., Barbosa, H. M. J., Crawford, I., Stern, R., Gallagher, M. W., Kaye, P. H., Allan, J. D., Coe, H., Artaxo, P., and McFiggans, G.: Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season, Atmos. Chem. Phys., 16, 9727-9743, doi:10.5194/acp-16-9727-2016, 2016.The Amazon basin is a vast continental area in which atmospheric composition is relatively unaffected by anthropogenic aerosol particles. Understanding the proper- ties of the natural biogenic aerosol particles over the Ama- zon rainforest is key to understanding their influence on re- gional and global climate. While there have been a number of studies during the wet season, and of biomass burning par- ticles in the dry season, there has been relatively little work on the transition period – the start of the dry season in the absence of biomass burning. As part of the Brazil–UK Net- work for Investigation of Amazonian Atmospheric Composi- tion and Impacts on Climate (BUNIAACIC) project, aerosol measurements, focussing on unpolluted biogenic air masses, were conducted at a remote rainforest site in the central Ama- zon during the transition from wet to dry season in July 2013. This period marks the start of the dry season but before sig- nificant biomass burning occurs in the region. Median particle number concentrations were 266 cm−3, with size distributions dominated by an accumulation mode of 130–150 nm. During periods of low particle counts, a smaller Aitken mode could also be seen around 80 nm. While the concentrations were similar in magnitude to those seen during the wet season, the size distributions suggest an en- hancement in the accumulation mode compared to the wet season, but not yet to the extent seen later in the dry sea- son, when significant biomass burning takes place. Submi- cron nonrefractory aerosol composition, as measured by an aerosol chemical speciation monitor (ACSM), was domi- nated by organic material (around 81 %). Aerosol hygro- scopicity was probed using measurements from a hygro- scopicity tandem differential mobility analyser (HTDMA), and a quasi-monodisperse cloud condensation nuclei counter (CCNc). The hygroscopicity parameter, κ , was found to be low, ranging from 0.12 for Aitken-mode particles to 0.18 for accumulation-mode particles. This was consistent with pre- vious studies in the region, but lower than similar measure- ments conducted in Borneo, where κ ranged 0.17–0.37. A wide issue bioaerosol sensor (WIBS-3M) was deployed at ground level to probe the coarse mode, detecting pri- mary biological aerosol by fluorescence (fluorescent biolog- ical aerosol particles, or FBAPs). The mean FBAP number concentration was 400 ± 242 L−1; however, this ranged from around 200 L−1 during the day to as much as 1200 L−1 at night. FBAPs dominated the coarse-mode particles, compris- ing between 55 and 75 % of particles during the day to more than 90 % at night. Non-FBAPs did not show a strong diur- nal pattern. Comparison with previous FBAP measurements above canopy at the same location suggests there is a strong vertical gradient in FBAP concentrations through the canopy. Cluster analysis of the data suggests that FBAPs were dom- inated (around 70 %) by fungal spores. Further, long-term measurements will be required in order to fully examine the seasonal variability and distribution of primary biological aerosol particles through the canopy. This is the first time that such a suite of measurements has been deployed at this site to investigate the chemical compo- sition and properties of the biogenic contributions to Ama- zonian aerosol during the transition period from the wet to the dry season, and thus provides a unique comparison to the aerosol properties observed during the wet season in previ- ous similar campaigns. This was also the first deployment of a WIBS in the Amazon rainforest to study coarse-mode parti- cles, particularly primary biological aerosol particles, which are likely to play an important role as ice nuclei in the region.Peer reviewe