Natural cross-ventilation of buildings, an experimental study

International audienceNatural cross ventilation can be a promising passive solution for summer thermal comfort in buildings. It takes advantage of the night temperature of the air to cool the walls of the building. Although this technique is well-known in hot climate, its use in new buildings requires being able to predict the quantity of heat that can be dissipated. There is indeed a lack of experimental data either to build design rules for engineers or to validate numerical code dedicated to the design. In this study, experimental research is carried out on a full-scale dwelling and a small-scale model, and evidence is given on the relevance of such a comparison. The flow has been estimated with spatially discrete local sensors in both systems, and flow visualizations have been additionally performed in the small-scale controlled model. For windy periods, the indoor airflow is found to be driven by the wind, as expected. For calm periods which are critical for summer comfort, the flows look much more complex with the observation of unsteady flow reversals

The genetic predictors of severe outcome in patients with anterior uveitis

Uveitis is a generic term for a wide variety of different types of intraocular inflammation with different clinical phenotypes and visual outcomes. The explanation for why some patients develop chronic anterior disease whereas others do not is unknown. It seems likely that host factors such as the cytokine milieu of the aqueous humor may be an important factor in determining outcome. In turn, their secretion is genetically determined and cytokine gene polymorphisms have been associated with high or low level production whatever the stimulus. Purpose: The aim of this study was to identify key cytokine and chemokine polymorphisms associated with disease susceptibility, clinical phenotype, and development of visually significant complications in patients with anterior uveitis. Methods: PCR amplification was used to genotype a number of biallelic SNPs in several cytokine genes. This genetic data was then compared between patients and healthy controls, and within the patient group itself for association with clinical disease outcomes. Results: Our results show that a significant difference in the frequency of TNF-857T allele in patients with idiopathic anterior uveitis. We found a significant association between TNF-308 allele G and patients with anterior uveitis who were HLA-B27 positive. Patients with HLA-B27 associated anterior uveitis who developed visually threatening complications were more likely to carry the TNFRSF1A-201T or TNFRSF1A-1135T alleles. In addition, the frequency of IL- 1ra allele T was found to be significantly associated with chronicity of the disease. The frequency of MCP-1 (-2076T) allele was found to be significantly higher in healthy individuals when compared to patients with acute idiopathic anterior uveitis. Conclusions: These results suggest that genetic variations in proinflammatory mediators may influence the susceptibility and severity of the inflammatory response in eyes of patients with anterior uveitis. This knowledge may be useful in identifying prognosis and responsiveness to anti-TNF blockade in patients with anterior uveitis

Link Between Increased Prevalence of Autism Spectrum Disorder Syndromes and Oxidative Stress, DNA Methylation, and Imprinting

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Back-side-on-BOX heterogeneously integrated III-V-on-silicon O-band discrete-mode lasers

We demonstrate foundry-fabricated O-band III-V-on-silicon discrete-mode lasers. The laser fabrication follows the back-side-on-buried-oxide laser integration process and is compatible with complex, multilayer, silicon-on-insulator based platforms. A series of devices were characterized, with the best devices producing on-chip powers of nearly 20 mW with Lorentzian linewidths below 20 kHz and a side mode suppression ratio of at least 60 dB

Endophthalmitis following penetrating eye injuries

Postinjury endophthalmitis is the eye infection with the worst prognosis. A retrospective 9-year study was made of penetrating eye injuries, with an analysis of the incidence of infection and its relation to the type of wound and the presence of intraocular foreign bodies. There were 403 cases of penetrating eye injury; of these, 233 affected the cornea and 170 involved the posterior pole. Intraocular foreign bodies were present in 40 cases. Endophthalmitis developed in 4.2% of cases (17/403), and was more common in patients with posterior pole involvement (7%) than in purely corneal trauma (2.1%) (p = 0.03, Chi-square). Infection was in turn more frequent in the presence of intraocular foreign bodies (15%) (p = 0.17, Chi-square). Staphylococcus epidermidis was the most common cause (23.4%), while in three cases (17.6%) mixed infection was detected. The visual results were evisceration or non-perception of light in 82.3% of cases

Impact of waveguide cross section on nonlinear impairments in integrated optical filters for WDM communication systems

Integrated optical chips enabling the realization of low-cost optical network units (ONU) is of great interest both for data centre solutions and for passive optical networks. In particular, in the frame of passive optical networks an interesting possibility is constituted by the presence, in the ONU of a Wavelength Division Multiplexing (WDM) filter [1] One of the most popular solution is based on a micro-ring resonators. The filter doesn’t introduce any relevant impairment in the downstream signal, as the optical power reaching the ONU, at the resonant wavelength, is generally so small that nonlinear effects can be generally neglected. Nevertheless, if the upstream signal, that generally has a much higher power, has to pass through the same resonator can undergo nonlinear effects like two-photon absorption (TPA), free-carriers absorption (FCA), and free-carrier dispersion (FCD) [2]. In this abstract we show the results of an experimental analysis we carried out in order to investigate the impact of optical nonlinear effects in WDM integrated micro-filters exploiting different designs (double- and triple- resonators structures, racetracks, rings, curved coupling regions, etc.) and exhibiting significantly different waveguide cross-sections (from 500 × 220 nm to 825 × 100 nm). The nonlinear behaviour evaluation has been carried out by performing two different sets of experiments. In the first one the amplified spontaneous emission emitted by an Er-doped fiber amplifier was filtered (by using a tunable filter with 5 nm band-width) and then amplified and then input by grating-assisted coupling to the filtering structures. Changes of filter transfer function were observed as a function of the input power. Conversely, in the second setup a narrowband CW-laser was used, and the behaviour of output power as a function of the input power was recorded

Fertilization and early embryology: Use of lasers in assisted fertilization and hatching

The erbium-yttrium-aluminium-garnet (Er: YAG) laser has been applied to micromanipulation in humans. It was used in the fertilization process for both subzonal insemination (SUZI) and for partial zona dissection (PZD). Laser-assisted micromanipulation achieved significantly higher fertilization rates (34.8%) when compared to mechanical SUZI (16.1%), but use of the laser did not improve the PZD results (laser 14.8% versus mechanical 14%). The Er: YAG laser was used to assist hatching. In the mouse it significantly improved the hatching rate (80 versus 29.3%) 110 h after administration of human chorionic gonadotrophin. This technique was applied in two different centres to patients with previous in-vitro fertilization (IVF) failures. The implantation rate per embryo (14.4% laser-assisted hatching versus 6% control group) and the pregnancy rate per transfer (40 versus 16.2%) were improve

De novo complex intra chromosomal rearrangement after ICSI: characterisation by BACs micro array-CGH

<p>Abstract</p> <p>Background</p> <p>In routine Assisted Reproductive Technology (ART) men with severe oligozoospermia or azoospermia should be informed about the risk of de novo congenital or chromosomal abnormalities in ICSI program. Also the benefits of preimplantation or prenatal genetic diagnosis practice need to be explained to the couple.</p> <p>Methods</p> <p>From a routine ICSI attempt, using ejaculated sperm from male with severe oligozoospermia and having normal karyotype, a 30 years old pregnant woman was referred to prenatal diagnosis in the 17^thweek for bichorionic biamniotic twin gestation. Amniocentesis was performed because of the detection of an increased foetal nuchal translucency for one of the fetus by the sonographic examination during the 12^thweek of gestation (WG). Chromosome and DNA studies of the fetus were realized on cultured amniocytes</p> <p>Results</p> <p>Conventional, molecular cytogenetic and microarray CGH experiments allowed us to conclude that the fetus had a <it>de novo </it>pericentromeric inversion associated with a duplication of the 9p22.1-p24 chromosomal region, 46,XY,invdup(9)(p22.1p24) [arrCGH 9p22.1p24 (RP11-130C19 → RP11-87O1)x3]. As containing the critical 9p22 region, our case is in coincidence with the general phenotype features of the partial trisomy 9p syndrome with major growth retardation, microcephaly and microretrognathia.</p> <p>Conclusion</p> <p>This de novo complex chromosome rearrangement illustrates the possible risk of chromosome or gene defects in ICSI program and the contribution of array-CGH for mapping rapidly de novo chromosomal imbalance.</p