On the Functional Significance of the P1 and N1 Effects to Illusory Figures in the Notch Mode of Presentation

The processing of Kanizsa figures have classically been studied by flashing the full “pacmen” inducers at stimulus onset. A recent study, however, has shown that it is advantageous to present illusory figures in the “notch” mode of presentation, that is by leaving the round inducers on screen at all times and by removing the inward-oriented notches delineating the illusory figure at stimulus onset. Indeed, using the notch mode of presentation, novel P1and N1 effects have been found when comparing visual potentials (VEPs) evoked by an illusory figure and the VEPs to a control figure whose onset corresponds to the removal of outward-oriented notches, which prevents their integration into one delineated form. In Experiment 1, we replicated these findings, the illusory figure was found to evoke a larger P1 and a smaller N1 than its control. In Experiment 2, real grey squares were placed over the notches so that one condition, that with inward-oriented notches, shows a large central grey square and the other condition, that with outward-oriented notches, shows four unconnected smaller grey squares. In response to these “real” figures, no P1 effect was found but a N1 effect comparable to the one obtained with illusory figures was observed. Taken together, these results suggest that the P1 effect observed with illusory figures is likely specific to the processing of the illusory features of the figures. Conversely, the fact that the N1 effect was also obtained with real figures indicates that this effect may be due to more global processes related to depth segmentation or surface/object perception

Plasmodium falciparum metacaspase PfMCA-1 triggers a z-VAD-fmk inhibitable protease to promote cell death.

Activation of proteolytic cell death pathways may circumvent drug resistance in deadly protozoan parasites such as Plasmodium falciparum and Leishmania. To this end, it is important to define the cell death pathway(s) in parasites and thus characterize proteases such as metacaspases (MCA), which have been reported to induce cell death in plants and Leishmania parasites. We, therefore, investigated whether the cell death function of MCA is conserved in different protozoan parasite species such as Plasmodium falciparum and Leishmania major, focusing on the substrate specificity and functional role in cell survival as compared to Saccharomyces cerevisae. Our results show that, similarly to Leishmania, Plasmodium MCA exhibits a calcium-dependent, arginine-specific protease activity and its expression in yeast induced growth inhibition as well as an 82% increase in cell death under oxidative stress, a situation encountered by parasites during the host or when exposed to drugs such as artemisins. Furthermore, we show that MCA cell death pathways in both Plasmodium and Leishmania, involve a z-VAD-fmk inhibitable protease. Our data provide evidence that MCA from both Leishmania and Plasmodium falciparum is able to induce cell death in stress conditions, where it specifically activates a downstream enzyme as part of a cell death pathway. This enzymatic activity is also induced by the antimalarial drug chloroquine in erythrocytic stages of Plasmodium falciparum. Interestingly, we found that blocking parasite cell death influences their drug sensitivity, a result which could be used to create therapeutic strategies that by-pass drug resistance mechanisms by acting directly on the innate pathways of protozoan cell death

The E-ELT first light spectrograph HARMONI: capabilities and modes

Trabajo presentado en SPIE Astronomical Telescopes, celebrado en San Diego (California), del 26 de junio al 1 de julio de 2016HARMONI is the E-ELT's first light visible and near-infrared integral field spectrograph. It will provide four different spatial scales, ranging from coarse spaxels of 60 × 30 mas best suited for seeing limited observations, to 4 mas spaxels that Nyquist sample the diffraction limited point spread function of the E-ELT at near-infrared wavelengths. Each spaxel scale may be combined with eleven spectral settings, that provide a range of spectral resolving powers (R 3500, 7500 and 20000) and instantaneous wavelength coverage spanning the 0.5 - 2.4 ¿m wavelength range of the instrument. In autumn 2015, the HARMONI project started the Preliminary Design Phase, following signature of the contract to design, build, test and commission the instrument, signed between the European Southern Observatory and the UK Science and Technology Facilities Council. Crucially, the contract also includes the preliminary design of the HARMONI Laser Tomographic Adaptive Optics system. The instrument's technical specifications were finalized in the period leading up to contract signature. In this paper, we report on the first activity carried out during preliminary design, defining the baseline architecture for the system, and the trade-off studies leading up to the choice of baseline

Mean amplitudes of the figure effect (illusory square vs. control figure in Experiment 1 and central square vs. peripheral squares in Experiment 2) for the four subsets of electrodes.

<p>Mean amplitudes of the figure effect (illusory square vs. control figure in Experiment 1 and central square vs. peripheral squares in Experiment 2) for the four subsets of electrodes.</p

The notch mode of presentation.

<p>Notches appear at onset and disappear at offset; full black disks remain on screen between trials. In half of the trials, notches were oriented inward so as to delineate a salient illusory square. In the other half of the trials, the control condition, notches were oriented outwards.</p

Physics-based model of the adaptive-optics-corrected point spread function: Applications to the SPHERE/ZIMPOL and MUSE instruments

International audienceContext. Adaptive optics (AO) systems greatly increase the resolution of large telescopes, but produce complex point spread function (PSF) shapes, varying in time and across the field of view. The PSF must be accurately known since it provides crucial information about optical systems for design, characterization, diagnostics, and image post-processing.Aims. We develop here a model of the AO long-exposure PSF, adapted to various seeing conditions and any AO system. This model is made to match accurately both the core of the PSF and its turbulent halo.Methods. The PSF model we develop is based on a parsimonious parameterization of the phase power spectral density, with only five parameters to describe circularly symmetric PSFs and seven parameters for asymmetrical ones. Moreover, one of the parameters is the Fried parameter r0 of the turbulence’s strength. This physical parameter is an asset in the PSF model since it can be correlated with external measurements of the r0, such as phase slopes from the AO real time computer (RTC) or site seeing monitoring.Results. We fit our model against end-to-end simulated PSFs using the OOMAO tool, and against on-sky PSFs from the SPHERE/ZIMPOL imager and the MUSE integral field spectrometer working in AO narrow-field mode. Our model matches the shape of the AO PSF both in the core and the halo, with a relative error smaller than 1% for simulated and experimental data. We also show that we retrieve the r0 parameter with sub-centimeter precision on simulated data. For ZIMPOL data, we show a correlation of 97% between our r0 estimation and the RTC estimation. Finally, MUSE allows us to test the spectral dependency of the fitted r0 parameter. It follows the theoretical λ6/5 evolution with a standard deviation of 0.3 cm. Evolution of other PSF parameters, such as residual phase variance or aliasing, is also discussed

Results of Experiment 1.

<p>(A) Identification of the left-sided electrodes used in the analyses. (B) Grand averaged VEPs (n = 15) elicited by the illusory square (dark blue) and the control figure (light blue). The black arrowhead identifies the P1 and the white arrowhead, the N1. The subtraction between the amplitudes of the two VEPs is also presented (thin gray line) to illustrate the magnitudes of the figure effect across the entire epoch. (C) Mean voltage maps illustrating the topographic scalp distribution of the VEP difference (subtractions) averaged within the time-windows of 70 to 130 ms (P1), 130 to 200 ms (N1), and 200 to 260 ms.</p

The MUSE Hubble Ultra Deep Field Survey XVI. The angular momentum of low-mass star-forming galaxies. A cautionary tale and insights from TNG50

published in A&A; The TNG50 data is now publicly available at https://www.tng-project.orgInternational audienceWe investigate the specific angular momentum (sAM) $j(<r)$ profiles of intermediate redshift ($0.4<z<1.4$) star-forming galaxies (SFGs) in the relatively unexplored regime of low masses (down to $M_\star\sim 10^8$M$_{\odot}$) and small sizes (down to $R_{\rm e}\sim 1.5$ kpc) and characterize the sAM scaling relation and its redshift evolution. We have developed a 3D methodology to constrain sAM profiles of the star-forming gas using a forward modeling approach with \galpak{} that incorporates the effects of beam smearing, yielding the intrinsic morpho-kinematic properties even with limited spatial resolution data. Using mock observations from the TNG50 simulation, we find that our 3D methodology robustly recovers the SFR-weighted $j(<r)$ profiles down to low effective signal-to-noise ratio (SNR) of $\gtrapprox3$. We apply our methodology blindly to a sample of 494 \OII{}-selected SFGs in the MUSE Ultra Deep Field (UDF) 9~arcmin$^2$ mosaic data, covering the unexplored $8<\log M_*/$M$_{\odot}<9$ mass range. We find that the (SFR-weighted) sAM relation follows $j\propto M_\star^{\alpha}$ with an index $\alpha$ varying from $\alpha=0.3$ to $\alpha=0.5$, from $\log M_\star/$M$_{\odot}=8$ to $\log M_*/$M$_{\odot}=10.5$. The UDF sample supports a redshift evolution consistent with the $(1+z)^{-0.5}$ expectation from a Universe in expansion. The scatter of the sAM sequence is a strong function of the dynamical state with $\log j|_{M_*}\propto 0.65 \times \log(V_{\rm max}/\sigma)$ where $\sigma$ is the velocity dispersion at $2 R_{\rm e}$. In TNG50, SFGs also form a $j-M_{\star}-(V/\sigma)$ plane but correlates more with galaxy size than with morphological parameters. Our results suggest that SFGs might experience a dynamical transformation before their morphological transformation to becoming passive via either merging or secular evolution

MAGIC: MUSE gAlaxy Groups In COSMOS – A survey to probe the impact of environment on galaxy evolution over the last 8 Gyr

Context: Galaxies migrate along filaments of the cosmic web from small groups to clusters, which creates the appearance that the evolution of their properties speeds up as environments get denser. Aims: We introduce the MUSE gAlaxy Groups in COSMOS (MAGIC) survey, which was built to study the impact of environment on galaxy evolution down to low stellar masses over the last 8 Gyr. Methods: The MAGIC survey consists of 17 Multi-Unit Spectrocopic Exporer (MUSE) fields targeting 14 massive, known structures at intermediate redshift (0.3 < z < 0.8) in the COSMOS area, with a total on-source exposure of 67 h. We securely measured the redshifts for 1419 sources and identified 76 galaxy pairs and 67 groups of at least three members using a friends-of-friends algorithm. The environment of galaxies is quantified from group properties, as well as from global and local density estimators. Results: The MAGIC survey has increased the number of objects with a secure spectroscopic redshift over its footprint by a factor of about 5 compared to previous extensive spectroscopic campaigns on the COSMOS field. Most of the new redshifts have apparent magnitudes in the z⁺⁺ band zₐₚₚ⁺⁺ > 21.5. The spectroscopic redshift completeness is high: in the redshift range of [O II] emitters (0.25 ≤ z  10¹⁰ M⊙, and the fraction of galaxies with M⋆ < 10⁹ M⊙ decreases significantly, even for star-forming galaxies. We also highlight peculiar features such as close groups, extended nebulae, and a gravitational arc. Conclusions: Our results suggest that galaxies are preprocessed in groups of increasing mass before entering rich groups and clusters. We publicly release two catalogs containing the properties of galaxies and groups, respectively.ISSN:0004-6361ISSN:1432-074

Randomized intergroup trial of cisplatin-paclitaxel versus cisplatin-cyclophosphamide in women with advanced epithelial ovarian cancer: three-year results.

BACKGROUND: A randomized trial conducted by the Gynecologic Oncology Group (GOG, study 111) in the United States showed a better outcome for patients with advanced ovarian cancer on the paclitaxel-cisplatin regimen than for those on a standard cyclophosphamide-cisplatin regimen. Before considering the paclitaxel-cisplatin regimen as the new "standard," a group of European and Canadian investigators planned a confirmatory phase III trial. METHODS: This intergroup trial recruited 680 patients with broader selection criteria than the GOG 111 study and administered paclitaxel as a 3-hour instead of a 24-hour infusion; progression-free survival was the primary end point. Patient survival was analyzed by use of the Kaplan-Meier technique. Treatment effects on patient survival were estimated by Cox proportional hazards regression models. All statistical tests were two-sided. RESULTS: The overall clinical response rate was 59% in the paclitaxel group and 45% in the cyclophosphamide group; the complete clinical remission rates were 41% and 27%, respectively; both differences were statistically significant (P =.01 for both). At a median follow-up of 38.5 months and despite a high rate of crossover (48%) from the cyclophosphamide arm to the paclitaxel arm at first detection of progression of disease, a longer progression-free survival (log-rank P =.0005; median of 15.5 months versus 11.5 months) and a longer overall survival (log-rank P =. 0016; median of 35.6 months versus 25.8 months) were seen in the paclitaxel regimen compared with the cyclophosphamide regimen. CONCLUSIONS: There is strong and confirmatory evidence from two large randomized phase III trials to support paclitaxel-cisplatin as the new standard regimen for treatment of patients with advanced ovarian cancer.Clinical TrialClinical Trial, Phase IIIJournal ArticleRandomized Controlled TrialResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe