Bistable Gestalts reduce activity in the whole of V1, not just the retinotopically predicted parts

Activity in the primary visual cortex reduces when certain stimuli can be perceptually organized as a unified Gestalt. This reduction could offer important insights into the nature of feedback computations within the human visual system; however, the properties of this response reduction have not yet been investigated in detail. Here we replicate this reduced V1 response, but find that the modulation in V1 (and V2) to the perceived organization of the input is not specific to the retinotopic location at which the sensory input from that stimulus is represented. Instead, we find a response modulation that is equally evident across the primary visual cortex. Thus in contradiction to some models of hierarchical predictive coding, the perception of an organized Gestalt causes a broad feedback effect that does not act specifically on the part of the retinotopic map representing the sensory input

Haemoglobin and size dependent constraints on swimbladder inflation in fish larvae

In developmental studies of fish species (especially physostomians) it could be demonstrated, that the lack of haemoglobin during larval and juvenile stages is a relatively common phenomenon. Generally it is linked with body translucency. In representatives of the families Galaxiidae, Osmeridae and Clupeidae, partly reared, partly observed immediately after being caught in the wild, it turned out, that this condition coincides with a considerable delay in swimbladder inflation. To determine the moment of its first inflation, larvae placed in a hermetic chamber were observed under a dissecting microscope. While lowering the pressure, the expanding swimbladder showed whether or not its content is really gaseous. The reason postulated to be responsible for the delayed inflation is that larvae lacking haemoglobin do not have the possibility of oxygen transport to their buoyancy organ by means of the blood. Apart of this, capillarity force calculations and body force estimations show that with decreasing size the constraints linked with surface tension increase overproportionally. While in larger sized larvae like trout we could demonstrate inflation by swallowing air, in species with small larvae this was not the case. Below a certain size, even in physostomians, the ductus pneumaticus is no alternative to the blood pathway for swimbladder inflation

Auto-oscillation threshold, narrow spectral lines, and line jitter in spin-torque oscillators based on MgO magnetic tunnel junctions

We demonstrate spin torque induced auto-oscillation in MgO-based magnetic tunnel junctions. At the generation threshold, we observe a strong line narrowing down to 6 MHz at 300K and a dramatic increase in oscillator power, yielding spectrally pure oscillations free of flicker noise. Setting the synthetic antiferromagnet into autooscillation requires the same current polarity as the one needed to switch the free layer magnetization. The induced auto-oscillations are observed even at zero applied field, which is believed to be the acoustic mode of the synthetic antiferromagnet. While the phase coherence of the auto-oscillation is of the order of microseconds, the power autocorrelation time is of the order of milliseconds and can be strongly influenced by the free layer dynamics

Size-sensitive perceptual representations underlie visual and haptic object recognition.

A variety of similarities between visual and haptic object recognition suggests that the two modalities may share common representations. However, it is unclear whether such common representations preserve low-level perceptual features or whether transfer between vision and haptics is mediated by high-level, abstract representations. Two experiments used a sequential shape-matching task to examine the effects of size changes on unimodal and crossmodal visual and haptic object recognition. Participants felt or saw 3D plastic models of familiar objects. The two objects presented on a trial were either the same size or different sizes and were the same shape or different but similar shapes. Participants were told to ignore size changes and to match on shape alone. In Experiment 1, size changes on same-shape trials impaired performance similarly for both visual-to-visual and haptic-to-haptic shape matching. In Experiment 2, size changes impaired performance on both visual-to-haptic and haptic-to-visual shape matching and there was no interaction between the cost of size changes and direction of transfer. Together the unimodal and crossmodal matching results suggest that the same, size-specific perceptual representations underlie both visual and haptic object recognition, and indicate that crossmodal memory for objects must be at least partly based on common perceptual representations

Fine-Scale Spatial Organization of Face and Object Selectivity in the Temporal Lobe: Do Functional Magnetic Resonance Imaging, Optical Imaging, and Electrophysiology Agree?

The spatial organization of the brain's object and face representations in the temporal lobe is critical for understanding high-level vision and cognition but is poorly understood. Recently, exciting progress has been made using advanced imaging and physiology methods in humans and nonhuman primates, and the combination of such methods may be particularly powerful. Studies applying these methods help us to understand how neuronal activity, optical imaging, and functional magnetic resonance imaging signals are related within the temporal lobe, and to uncover the fine-grained and large-scale spatial organization of object and face representations in the primate brain

Numerical CFD modelling of non-neutral atmospheric boundary layers for offshore wind resource assessment based on Monin-Obukhov theory

The presented works aim at proposing a methodology for the simulation of offshore wind conditions using CFD. The main objective is the development of a numerical model for the characterization of atmospheric boundary layers of different stability levels, as the most important issue in offshore wind resource assessment. Based on Monin-Obukhov theory, the steady k-ε Standard turbulence model is modified to take into account thermal stratification in the surface layer. The validity of Monin-Obukhov theory in offshore conditions is discussed with an analysis of a three day episode at FINO-1 platform

Auto-oscillation threshold and line narrowing in MgO-based spin-torque oscillators

We present an experimental study of the power spectrum of current-driven magnetization oscillations in MgO tunnel junctions under low bias. We find the existence of narrow spectral lines, down to 8 MHz in width at a frequency of 10.7 GHz, for small applied fields with clear evidence of an auto-oscillation threshold. Micromagnetics simulations indicate that the excited mode corresponds to an edge mode of the synthetic antiferromagnet

Socio-economic inequalities in injury incidence in the Netherlands

Background: Interventions to reduce socio-economic inequalities in injury incidence should be tailored to specific priority areas that may be identified by descriptive studies. We aimed to provide an overview of exist

Voorspellende factoren van functionele beperkingen na ernstig letsel

OBJECTIVE: To assess the health-related quality of life and prognostic factors of disability in survivors of severe trauma one year after injury. DESIGN:Prospective cohort study. METHOD: All severely-injured trauma patients presenting at a level I trauma centre during a 30-month period and surviving 30 days after admission were included. The EuroQol-5D (EQ-5D) and Health Utilities Index (HUI) were used to determine the health status 12 months after injury. RESULTS: 362 patients were included during the study period, 246 of whom returned the follow-up assessments (response rate: 68%). The median EQ-5D utility score was 0.73 (EQ-5D Dutch general population norm: 0.88). The HUI2, HUI3 and EQ-5D Visual Analogue Scale scores were 0.81, 0.65 and 70, respectively. One year after trauma only 22% of the patients reported no functional limitation in the 5 domains of the EQ-D5. Females and patients with co-morbidity at the time of the injury had a higher risk of low scores after 1 year. CONCLUSION: One year after severe injury, the functional outcome and quality of life of trauma patients were far from normalized. Female gender and comorbidity were predictors of poorer functional outcome

Willingness to pay for lives saved by helicopter emergency medical services

Introduction. Currently, policy makers in the Netherlands are discussing the possibility to expand the availability of Helicopter Emergency Medical Services (HEMS) from 12 hours to 24 hours per day. For this, the preferences of the general public towards both the positive effects and negative consequences of HEMS should be taken into account. Therefore, the willingness to pay (WTP) for lives saved by HEMS was calculated. Methods. A discrete choice experiment (DCE) was performed in order to explore the preferences of respondents towards (expansion of) HEMS availability. The attributes: costs (for HEMS) per household number of additional lives saved (by HEMS), number of noise disturbances (caused by HEMS) during day time or night time were used. A written questionnaire was presented to 150 individuals by convenience sampling. Result. One hundred and thirty-six (91%) of the 150 individuals completed the DCE questionnaire. The marginal WTP for one additional life saved (in a month) was 3.43 (95% CI; 2.96-3.90) per month per household. Overall, the WTP for expansion to a 24-hour availability of HEMS can therefore be estimated at 12.29 (∼ US$ 17.50) per household per month. Conclusion. The WTP derived from this study is by far exceeding the 1-1.5 Million-euro necessary per HEMS per year for the expansion from a daytime HEMS to a 24-h availability in the Netherlands. Respondents are willing to pay for lives saved by HEMS in spite of increases in flights and concurrent noise disturbances. These results may be helpful for the decision-making process,