Gappy PCA Classification for Occlusion Tolerant 3D Face Detection

This paper presents an innovative approach for the detection of faces in three dimensional scenes. The method is tolerant against partial occlusions produced by the presence of any kind of object. The detection algorithm uses invariant properties of the surfaces to segment salient facial features, namely the eyes and the nose. At least two facial features must be clearly visible in order to perform face detection. Candidate faces are then registered using an ICP (Iterative Correspondent Point) based approach aimed to avoid those samples which belong to the occluding objects. The final face versus non-face discrimination is computed by a Gappy PCA (GPCA) classifier which is able to classify candidate faces using only those regions of the surface which are considered to be non-occluded. The algorithm has been tested using the UND database obtaining 100% of correct detection and only one false alarm. The database has been then processed with an artificial occlusions generator producing realistic acquisitions that emulate unconstrained scenarios. A rate of 89.8% of correct detections shows that 3D data is particularly suited for handling occluding objects. The results have been also verified on a small test set containing real world occlusions obtaining 90.4% of correctly detected faces. The proposed approach can be used to improve the robustness of all those systems requiring a face detection stage in non-controlled scenarios.

Cooperative Constrained Control of Distributed Agents With Nonlinear Dynamics and Delayed Information Exchange: A Stabilizing Receding-Horizon Approach

This paper addresses the problem of cooperative control of a team of distributed agents with decoupled nonlinear discrete-time dynamics, which operate in a common environment and exchange-delayed information between them. Each agent is assumed to evolve in discrete-time, based on locally computed control laws, which are computed by exchanging delayed state information with a subset of neighboring agents. The cooperative control problem is formulated in a receding-horizon framework, where the control laws depend on the local state variables (feedback action) and on delayed information gathered from cooperating neighboring agents (feedforward action). A rigorous stability analysis exploiting the input-to-state stability properties of the receding-horizon local control laws is carried out. The stability of the team of agents is then proved by utilizing small-gain theorem results.      

MCAM/MUC18/CD146 as a Multifaceted Warning Marker of Melanoma Progression in Liquid Biopsy

Human malignant melanoma shows a high rate of mortality after metastasization, and its incidence is continuously rising worldwide. Several studies have suggested that MCAM/MUC18/CD146 plays an important role in the progression of this malignant disease. MCAM/MUC18/CD146 is a typical single-spanning transmembrane glycoprotein, existing as two membrane isoforms, long and short, and an additional soluble form, sCD146. We previously documented that molecular MCAM/MUC18/CD146 expression is strongly associated with disease progression. Recently, we showed that MCAM/MUC18/CD146 and ABCB5 can serve as melanoma-specific-targets in the selection of highly primitive circulating melanoma cells, and constitute putative proteins associated with disease spreading progression. Here, we analyzed CD146 molecular expression at onset or at disease recurrence in an enlarged melanoma case series. For some patients, we also performed the time courses of molecular monitoring. Moreover, we explored the role of soluble CD146 in different cohorts of melanoma patients at onset or disease progression, rather than in clinical remission, undergoing immune therapy or free from any clinical treatment. We showed that MCAM/MUC18/CD146 can be considered as: (1) a membrane antigen suitable for identification and enrichment in melanoma liquid biopsy; (2) a highly effective molecular “warning” marker for minimal residual disease monitoring; and (3) a soluble protein index of inflammation and putative response to therapeutic treatments.     

Preliminary results on thermo-oxidative ageing of multi-hole carbon/epoxy composites

During their service life, fibre-reinforced polymers are subjected to the influences of numerous ageing factors such as temperature, pressure, oxygen or moisture, which generally result in a decrease of the composite properties. This study deals with the combined actions of two damaging parameters, temperature and oxygen. Thermo-oxidation is analysed in an original way by ageing in air plain and multi-hole laminates for 9000 h. Since perforated panels have a greater surface exposed to the oxidative environment, the degradation due to oxygen is increased, thus allowing a better understanding of thermo-oxidation mechanisms. Characterisation of the aged composite includes FTIR, microscopy, weight loss measurements, DMA, compression and SBS tests. Thermo-oxidative ageing leads to oxidation and cracking of the laminates surfaces, weight loss and decrease of both compression and SBS failure strengths. The glass transition temperature remains constant. Degradation is more important for the multi-hole panels and results in a greater decrease of the physical and mechanical properties for these laminates.     

A computational strategy exploiting genetic algorithms to recover color surface reflectance functions

Information about the spectral reflectance of a color surface is useful in many applications. Assuming that reflectance functions can be adequately approximated by a linear combination of a small number of basis functions, we address here the recovery of a surface reflectance function, given the tristimulus values under one or more illuminants. Basis functions presenting different characteristics and cardinalities are investigated, and genetic algorithms are employed to optimize the estimation. Our analysis of a variety of standard datasets provides information about the ability of each set of basis functions we used to model generic reflectance spectra.     

Anomalous behavior of thermal conductivity and diffusivity in polymeric materials filled with metallic particles

Thermal properties of two composites prepared by using a polypropylene matrix filled with aluminum (slightly oxidized) and copper fillers were investigated. For each of these fillers two different particle sizes were used. We have shown an anomalous thermal behavior when these metallic fillers are slightly oxidized, i.e. higher thermal transport is obtained for PP/Al composites when using the largest particles. So, the PP/Al composites thermal behavior is not consistent with the PP/Cu ones and with the literature results reported for dielectric or conducting filler particles in a polymeric matrix. Thus, these PP/Al composites exhibit higher thermal transport properties than the homopolymer matrix where as electrical insulating properties of PP are preserved. This kind of composite structure might be of great interest in some technological applications where both good electrical insulation and high thermal conduction are required.     

Factors Ruling the Uptake of Silica Nanoparticles by Mesenchymal Stem Cells: Agglomeration Versus Dispersions,Absence Versus Presence of Serum Proteins

The results of a systematic investigation of the role of serum proteins on the interaction of silica nanoparticles (NP) doped in their bulk with fluorescent molecules (IRIS Dots, 50 nm in size), with human mesenchymal stem cells (hMSCs) are reported. The suspension of IRIS Dots in bare Dulbecco‐modified Eagle's medium results in the formation of large agglomerates (≈1.5 μm, by dynamic light scattering), which become progressively smaller, down to ≈300 nm in size, by progressively increasing the fetal bovine serum (FBS) content of the solutions along the series 1.0%, 2.5%, 6.0%, and 10.0% v/v. Such difference in NP dispersion is maintained in the external cellular microenvironment, as observed by confocal microscopy and transmission electron microscopy. As a consequence of the limited diffusion of proteins in the inter‐NP spaces, the surface of NP agglomerates is coated by a protein corona independently of the agglomerate size/FBS concentration conditions (ζ‐potential and UV circular dichroism measurements). The protein corona appears not to be particularly relevant for the uptake of IRIS Dots by hMSCs, whereas the main role in determining the internalization rate is played by the absence/presence of serum proteins in the extracellular media.     

Categories of indoor environmental quality and building energy demand for heating and cooling

Maintaining suitable indoor climate conditions is a need for the occupants’ well being, while requiring very strictly thermal comfort conditions and very high levels of indoor air quality in buildings represents also a high expense of energy, with its consequence in terms of environmental impact and cost. In fact, it is well known that the indoor environmental quality (IEQ), considering both thermal and indoor air quality aspects, has a primary impact not only on the perceived human comfort, but also on the building energy consumption. This issue is clearly expressed by the European Energy Performance of Buildings Directive 2002/92/EC, together with the most recent 2010/31/EU, which underlines that the expression of a judgment about the energy consumption of a building should be always joint with the corresponding indoor environmental quality level required by occupants. To this aim, the concept of indoor environment categories has been introduced in the EN 15251 standard. These categories range from I to III, where category I refers to the highest level of indoor climate requirement. In the challenge of reducing the environmental impact for air conditioning in buildings, it is essential that IEQ requirements are relaxed in order to widen the variations of the temperature ranges and ventilation air flow rates. In this paper, by means of building energy simulation, the heating and cooling energy demand are calculated for a mechanically controlled office building where different indoor environmental quality levels are required, ranging from category I to category III of EN 15251. The building is located in different European cities (Moscow, Torino and Athens), characterized by significantly different wheatear conditions. The mutual relation between heating and cooling energy demand and the required levels of IEQ is highlighted. The simulations are performed on a typical office room which is adopted as a reference in validation tests of the European Standard EN 15265 to validate calculation procedures of energy use for space heating and cooling.     

A simple protocol for paraffin-embedded myelin sheath staining with osmium tetroxide for light microscope observation

Experimental investigation of peripheral nerve fiber regeneration is attracting more and more attention among both basic and clinical researchers. Assessment of myelinated nerve fiber morphology is a pillar of peripheral nerve regeneration research. The gold standard for light microscopic imaging of myelinated nerve fibers is toluidine blue staining of resin-embedded semithin sections. However, many researchers are unaware that the dark staining of myelin sheaths typically produced by this procedure is due to osmium tetroxide postfixation and not due to toluidine blue. In this article, we describe a simple pre-embedding protocol for staining myelin sheaths in paraffin-embedded nerve specimens using osmium tetroxide. The method involves immersing the specimen in 2% osmium tetroxide for 2 h after paraformaldehyde fixation, followed by routine dehydration and paraffin embedding. Sections can then be observed directly under the microscope or counterstained using routine histological methods. Particularly good results were obtained with Masson's trichrome counterstain, which permits the imaging of connective structures in nerves that are not detectable in toluidine blue-stained resin sections. Finally, we describe a simple protocol for osmium etching of sections, which makes further immunohistochemical analysis possible on the same specimens. Taken together, our results suggest that the protocol described in this article is a valid alternative to the conventional resin embedding-based protocol: it is much cheaper, can be adopted by any histological laboratory, and allows immunohistochemical analysis to be conducted.     

A Study on Skin Delaminations Growth in Stiffened Composite Panels by a Novel Numerical Approach

In this paper, a study on skin delamination growth in stiffened composite panels made of carbon fibres reinforced polymers and subjected to compressive load is presented. A robust (mesh and time step independent) numerical finite elements procedure, based on the Virtual Crack Closure Technique (VCCT) and on the fail release approach, is used here to investigate the influence of skin delamination size and position on the damage tolerance of stiffened composite panels. Four stiffened panels configurations with skin delaminations differently sized and positioned are introduced. Bay delaminations and delaminations under the stringer foot are considered. The novel numerical procedure has been used to simulate the delamination growth for all the investigated panel configurations and to evaluate the influence of the delaminations’ geometrical parameters on the growth development. As a confirmation of the applicability and effectiveness of the adopted numerical tool, the numerical results, obtained for all the analysed configurations, in terms of grown delaminated area, displacements and strains measured in various panel locations, have been compared with experimental data available in literature.