Silent surfaces : an experience in Portugal

It is acknowledged that traffic noise affects human behaviour and health. Measures aiming at mitigating the impact of traffic noise are not always viable in urban areas. In Portugal, road designers have recently started to consider silent surfaces as alternative within their road pavement projects. In this paper the tire-surface noise of three surface layers integrated in a rehabilitation project carried out in an urban road that carries more than 40000 vehicles per day is assessed: i) one dense asphalt layer with limited maximum aggregate size, following the SILVIA recommendations for low noise surfaces; ii) two very-thin surfaces with different grading, which are an adaptation of the very-thin layers widely used in France to Portuguese conditions. The surface layers were constructed consecutively, involving segment lengths with more than 500 m. The surface texture was measured using a high speed profilometer. Skid resistance was also measured. The noise level was measured both by pass-by tests with selected traffic (trucks and light vehicles) at several speeds and by close proximity tests. The thin layers tested provided very good noise reduction values, especially at high speeds, and had a better performance than gap graded asphalt rubber surfaces frequently used in Portugal

A unique population of effector memory lymphocytes identified by CD146 having a distinct immunophenotypic and genomic profile

<p>Abstract</p> <p>Background</p> <p>CD146 is a well described homotypic adhesion molecule found on endothelial cells and a limited number of other cell types. In cells from the peripheral circulation, CD146 has also been reported to be on activated lymphocytes <it>in vitro </it>and <it>in vivo</it>. The function associated with CD146 expression on lymphoid cells is unknown and very little information is available concerning the nature of CD146+ lymphocytes. In the current study, lymphocytes from healthy donors were characterized based upon the presence or absence of CD146 expression.</p> <p>Results</p> <p>CD146 was expressed on a low percentage of circulating T lymphocytes, B lymphocytes, and NK cells in healthy individuals. CD146 expression can be induced and upregulated <it>in vitro </it>on both B cells and T cells, but does not correlate with the expression of other markers of T cell activation. CD146 positive T cells do not represent clonal expansions as determined with the use of anti Vβ reagents. Data suggest that CD146 positive cells have enhanced adherence to endothelial monolayers in vitro. Gene profiling and immunophenotyping studies between CD146+ and CD146- T cells revealed several striking genotypic distinctions such as the upregulation of IL-8 and phenotypic differences including the paucity of CCR7 and CD45RA among CD146 positive T cells, consistent with effector memory function. A number of genes involved in cell adhesion, signal transduction, and cell communication are dramatically upregulated in CD146+ T cells compared to CD146- T cells.</p> <p>Conclusion</p> <p>CD146 appears to identify small, unique populations of T as well as B lymphocytes in the circulation. The T cells have immunophenotypic characteristics of effector memory lymphocytes. The characteristics of these CD146+ lymphocytes in the circulation, together with the known functions in cell adhesion of CD146 on endothelial cells, suggests that these lymphocytes may represent a small subpopulation of cells primed to adhere to the endothelium and possibly extravasate to sites of inflammation.</p

Perivascular-like cells contribute to the stability of the vascular network of osteogenic tissue formed from cell sheet-based constructs

In recent years several studies have been supporting the existence of a close relationship in terms of function and progeny between Mesenchymal Stem Cells (MSCs) and Pericytes. This concept has opened new perspectives for the application of MSCs in Tissue Engineering (TE), with special interest for the pre-vascularization of cell dense constructs. In this work, cell sheet technology was used to create a scaffold-free construct composed of osteogenic, endothelial and perivascular-like (CD146+) cells for improved in vivo vessel formation, maturation and stability. The CD146 pericyte-associated phenotype was induced from human bone marrow mesenchymal stem cells (hBMSCs) by the supplementation of standard culture medium with TGF-b1. Co-cultured cell sheets were obtained by culturing perivascular-like (CD146+) cells and human umbilical vein endothelial cells (HUVECs) on an hBMSCs monolayer maintained in osteogenic medium for 7 days. The perivascular-like (CD146+) cells and the HUVECs migrated and organized over the collagen-rich osteogenic cell sheet, suggesting the existence of cross-talk involving the co-cultured cell types. Furthermore the presence of that particular ECM produced by the osteoblastic cells was shown to be the key regulator for the singular observed organization. The osteogenic and angiogenic character of the proposed constructs was assessed in vivo. Immunohistochemistry analysis of the explants revealed the integration of HUVECs with the host vasculature as well as the osteogenic potential of the created construct, by the expression of osteocalcin. Additionally, the analysis of the diameter of human CD146 positive blood vessels showed a higher mean vessel diameter for the co-cultured cell sheet condition, reinforcing the advantage of the proposed model regarding blood vessels maturation and stability and for the in vitro pre-vascularization of TE constructs.Funding provided by Fundacao para a Ciencia e a Tecnologia project Skingineering (PTDC/SAU-OSM/099422/2008). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

"Dangerous to Themselves and Others, and of Public Scandal": The Internment Procedure

Abstract Through G.'s admission and medical files, this chapter illustrates internment laws and procedures, highlighting how Fascism pushed pre-existing legislation to its extreme consequences. In reconstructing internment's bureaucratic and legal practices, the chapter emphasises how the law could be bent to accommodate the regime's need to isolate those perceived as "different" and how psychiatry acquiesced in offering to "correct" individuals considered "non-conforming", "amoral", "immoral", "deviant", rebellious and, among them, homosexuals, in exchange for an increase of power and status

Elastic wave propagation in a three-dimensional periodic granular medium

We present an experimental study of acoustic wave propagation in granular media made of mono-disperse spherical beads under stress and periodically arranged. A previous work presented the predominance of multiple-scattered acoustic waves for random closed-packing granular media, whereas our experimental results lead to the conclusion that the acoustical propagation in our arrangement of spherical beads proceeds essentially from surface waves. This provides another mechanism for the understanding of acoustical wave propagation in granular media, that may be useful at least to analyse weak disorder ones

«Adrienne» a European method to qualify road noise barriers on site

Adrienne is a method developed in a European research project, the aim of which was the measurement on site of sound absorption and sound transmission of any road noise barrier. In order to get the impulse response of the device (absorption measurement), a M.L.S. (Maximum Length Sequence) method was selected mainly for its excellent signal/noise ratio. The introduction of a subtraction technique improves the low frequency information. For flat barriers, measurement results showed a good agreement with well-known models or other experimental methods. For non flat barriers, numerical predictions resulted in the requirement of an averaging performed on many source and receiver positions. An encouraging agreement between measurements and predictions was found. Round robin tests on a specially built platform proved a good repeatability of the method

Dependance of the contact area on the velocity of a rolling tire

Tires are made of viscoelastic materials with stiffness quite dependent on the frequency. Generally, two causes of the stiffness increase are distinguished : a frequency dependence complex modulus and a geometrical stiffness. In this paper, an experimental and theoretical study on the relaxation and frequency dependence of complex moduli of the tire constitutive materials are presented and validated. Expressions of the viscoelastic behavior are presented in time and frequency domains. The results show that the real part of the Young's modulus is monotonic according to the frequency. It contributes to an important part of the stiffening. A numerical approach simulating the experimental results of the contact area of Cesbron is also presented. The tire is modeled with a real material distribution in the tire section. The geometrical stiffness also increases with the rotational velocity and it varies with the vibration frequencies. Static and dynamic computations for different rolling velocities are done. The results show that the contact area depends on the velocity of the rolling tire. Comparisons between the measurements and the computations show a good agrement and a decrease of about 20% in the contact areas when the tire rolls compared to a static tire. This difference can be explained by the viscoelastic properties of the materials