Towards Invisible Eye Tracking with Lens-Coupled Lateral Photodetectors

A novel low-power and easy to integrate sensing configuration for wearable eye tracking is presented. Within the context of infrared oculography based on individual photosensors, we proposed to couple a set of photodetectors to the lateral edges of a standard lens, acting as waveguide for the IR light, instead of directing them towards the eyeball. This allows to embed the detectors in the rim, thus being fully hidden in the eyewear, invisible to the user and robustly integrated with the glasses. A preliminary setup with four photodiodes whose signals are processed by an agile two-layer neural network was realized and characterized. Here we demonstrate both experimentally and by means of simulations the feasibility of this patent-pending approach. Detected maps of light patterns respond to different impinging light orientations. An angular resolution of about 5 degrees is achieved with only 4 individual photodetectors coupled to a thick rectangular glass lens. A larger number of detectors would provide better resolutions. The parameters of ray-tracing simulations were first adjusted to match the experimental data from a simplified geometry. Then, simulations were used to estimate the expected signals with an eye model, paving the way to a promising outlook. The combination of hardware and software solutions here presented aims at addressing the trade-off between power consumption and angular resolution in the estimation of the direction of gaze which is crucial for pervasive eye tracking

Challenges in Acquiring Clinical Simultaneous SPECT-MRI on a PET-MRI Scanner

The INSERT is the world’s first clinical SPECTMRI brain imaging system based on scintillation detectors with a SiPM readout. Here we demonstrate its use within a clinical MRI environment for the first time. Using a standard transmit-receive head coil, and with an appropriate selection of a custom MRI sequence (GRE), we overcome mutual interference. The INSERT and its bulky 50 kg tungsten collimator introduce magnetic field inhomogeneity. Due to the specific MRI-compatible collimator design, inhomogeneity is compensated by shimming, leading to simultaneous acquisition. We process the SPECT data acquired alongside the MRI sequence to evaluate the SPECT system performance and the impact of the MRI. Finally, we present a set of simultaneous SPECT-MRI acquisitions, demonstrating multimodal imaging capabilities, albeit with a limited MRI sequence

Global value chains and deep integration

The post-1990 period has seen a proliferation of preferential trade agreements (PTAs). Some 700 PTAs are currently in force, compared to a little more than 100 PTAs before 1990. Both developed and developing countries have been and are deeply involved in preferential trade liberalisation. While tariff reductions on a preferential basis are a central feature of all trade agreements, the inclusion of provisions that do not pertain directly to merchandise trade policies – e.g. provisions protecting foreign investment (FDI) and liberalising access to markets for services – has become increasingly common in PTAs. As a result, many PTAs regulate trade-related issues more extensively and more stringently than the WTO. Simply put, preferential liberalisation has become the main instrument of trade policy cooperation

Adhesion of Immature and Mature T Cells Induces in Human Thymic Epithelial Cells (TEC) Activation of IL-6 Gene Trascription Factors (NF-κB And NF-IL6) and IL-6 Gene Expression : Role of αtβ1 and α6β4 Integrins

T cell precursors homed to thymus develop in close contact with stromal cells. Among them, thymic epithelial cells (TEC) are known to exert dominant roles in their survival and functional shaping. Key molecules mediating TEC/thymocytes interactions include cytokines and growth factors secreted by the two cell types and adhesion receptors mediating cell contact. Signaling events triggered in thymocytes by adhesion to epithelial cells have been extensively investigated, whereas little is known on the opposite phenomenon. We have previously investigated this issue in a co-culture system composed of TEC cultures derived from human normal thymus and heterologous thymocytes. We demonstrated that thymocytes adhere to TEC involving β1 and β4 integrins and induce the clustering of (α3β1 and α6β4 heterodimers at the TEC surface. In addition thymocyte adhesion was followed by activation of NF-κB and NF-IL6 gene transciption factors and enhanced IL-6 production. The two latter phenomena were reproduced by the cross-linking of the α3, α6, β1 and β4 integrins, thus implying that the α3β1 and α6β4 heterodimers can signal during thymocyte adhesion. We have extended our previous work investigating in the same experimental setting the inducing activity of non stimulated or activated policlonal or clonal mature T cells as representative of the more mature thymocyte subset. We found that adhesion of unstimulated T cell i) involved β1, but not β4 integrin functions at the surface ii) induced the clustering of α3β1 , but not α2β1 heterodimers at the TEC surface and iii) up-regulated the nuclear binding activity of NF-κB transcription factor and the IL-6 secretion. We propose that α3β1 and α6β4 heterodimers are induced to cluster at the TEC surface recognizing yet unknown cellular ligands differentially expressed during T cell development

Characterization of a Silicon Drift Detector for High-Resolution Electron Spectroscopy

Silicon Drift Detectors, widely employed in high-resolution and high-rate X-ray applications, are considered here with interest also for electron detection. The accurate measurement of the tritium beta decay is the core of the TRISTAN (TRitium Investigation on STerile to Active Neutrino mixing) project. This work presents the characterization of a single-pixel SDD detector with a mono-energetic electron beam obtained from a Scanning Electron Microscope. The suitability of the SDD to detect electrons, in the energy range spanning from few keV to tens of keV, is demonstrated. Experimental measurements reveal a strong effect of the detector's entrance window structure on the observed energy response. A detailed detector model is therefore necessary to reconstruct the spectrum of an unknown beta-decay source

Global value chains and the design of trade agreements

We explore the role of global value chains (GVCs) in the design of preferential trade agreements (PTAs). We propose a theory that focuses on firms involved in backward and forward GVC activities to identify the main actors pushing for deep trade integration. To address the critical issue of endogeneity of trade flows for trade policy, our identification strategy exploits a transportation shock: The sharp increase in the maximum size of container ships, which more than quadrupled between 1995 and 2017. The key variation in our instrument hinges on the fact that only deepwater ports can accommodate these new larger ships. Our strategy is flexible enough to generate excludable instruments for different value-added components of exports, which allows us to disaggregate the causal effect of GVC participation into backward and forward GVC activities. We find that trade through GVCs increases the probability of forming deep PTAs that include provisions regulating both trade-related and non-trade-related policies. We find also evidence that GVC activities affect the flexibility of PTAs. Our results indicate that trade intermediation by producers is the main driver of the design of trade agreements

Biochemical and neuropathological findings in a Creutzfeldt-Jakob Disease patient with the rare Val180Ile-129Val haplotype in the prion protein gene

Genetic Creutzfeldt-Jakob disease (gCJD) associated with the V180I mutation in the prion protein (PrP) gene (PRNP) in phase with residue 129M is the most frequent cause of gCJD in East Asia, whereas it is quite uncommon in Caucasians. We report on a gCJD patient with the rare V180I-129V haplotype, showing an unusually long duration of the disease and a characteristic pathological PrP (PrPSc) glycotype. Family members carrying the mutation were fully asymptomatic, as commonly observed with this mutation. Neuropathological examination showed a lesion pattern corresponding to that commonly reported in Japanese V180I cases with vacuolization and gliosis of the cerebral cortexes, olfactory areas, hippocampus and amygdala. PrP was deposited with a punctate, synaptic-like pattern in the cerebral cortex, amygdala and olfactory tract. Western blot analyses of proteinase-K-resistant PrP showed the characteristic two-banding pattern of V180I gCJD, composed of mono- and un-glycosylated isoforms. In line with reports on other V180I cases in the literature, Real-Time Quaking Induced Conversion (RT-QuIC) analyses did not demonstrate the presence of seeding activity in the cerebrospinal fluid and olfactory mucosa, suggesting that this haplotype also may result in a reduced seeding efficiency of the pathological PrP. Further studies are required to understand the origin, penetrance, disease phenotype and transmissibility of 180I-129V haplotype in Caucasians