Phase modulators ands splitting network on Si PIC coherent fiber beam combining

Coherent beam combining (CBC) of fiber lasers provide an attractive mean of reaching high output laser power by scaling up the available energy while keeping fiber intrinsic advantages of compactness, reliability, efficiency, and beam quality. In CBC architectures, the power of a master oscillator (MO) is divided into N fibers that are amplified individually. The phase perturbations between channels can be measured using various techniques [1-3] and are corrected by individual phase modulators placed on each fiber before the amplification. In this Communication, we present a Silicon PIC integrating a 1:16 channels splitting network and thermal phase modulators array with low electrical power consumption and a bandwidth compatible with CBC requirements. In our CBC system, a 1.55µm CW master oscillator directly feeds the Silicon chip through a grating coupler, as shown in Fig.1(a). The power of the master oscillator is first split on chip into 16 channels, each of which including a thermal phase modulator. The outputs of the 16 waveguides are collectively out-coupled from the chip using a PM optical fiber array aligned and glued onto the PIC’s output grating couplers array [4]. At the other end of fiber array, the 16 fiber outputs are arranged in a 4 by 4 squared lattice, and collimated by a microlens array to form 16 collimated and parallel beamlets. The phase distribution from channel to channel is derived from the fringe pattern resulting from the collimated beamlets interfering with a reference plane wave on a camera. This signal is fed back to drive the PIC’s phase modulators in order to phase lock the 16 fiber

Silicon photonics frequency shifter based on I&Q dual Mach-Zehnder modulator

We present a fully CMOS compatible frequency shifter device, in a I&Q dual Mach-Zehnder architecture. Frequency shift up to 410 MHz are obtained, with carrier and image sideband extinction from 27 to 51 dB

Phase modulators and splitting network on Si PIC for coherent fiber beam combining

Coherent beam combining (CBC) of fiber lasers provide an attractive mean of reaching high output laser power by scaling up the available energy while keeping fiber intrinsic advantages of compactness, reliability, efficiency, and beam quality. In CBC architectures, the power of a master oscillator (MO) is divided into N fibers that are amplified individually. The phase perturbations between channels can be measured using various techniques [1-3] and are corrected by individual phase modulators placed on each fiber before the amplification. In this Communication, we present a Silicon PIC integrating a 1:16 channels splitting network and thermal phase modulators array with low electrical power consumption and a bandwidth compatible with CBC requirements

Childhood lead exposure in France: benefit estimation and partial cost-benefit analysis of lead hazard control

<p>Abstract</p> <p>Background</p> <p>Lead exposure remains a public health concern due to its serious adverse effects, such as cognitive and behavioral impairment: children younger than six years of age being the most vulnerable population. In Europe, the lead-related economic impacts have not been examined in detail. We estimate the annual costs in France due to childhood exposure and, through a cost benefit analysis (CBA), aim to assess the expected social and economic benefits of exposure abatement.</p> <p>Methods</p> <p>Monetary benefits were assessed in terms of avoided national costs. We used results from a 2008 survey on blood-lead (B-Pb) concentrations in French children aged one to six years old. Given the absence of a threshold concentration being established, we performed a sensitivity analysis assuming different hypothetical threshold values for toxicity above 15 μg/L, 24 μg/L and 100 μg/L. Adverse health outcomes of lead exposure were translated into social burden and economic costs based on literature data from literature. Direct health benefits, social benefits and intangible avoided costs were included. Costs of pollutant exposure control were partially estimated in regard to homes lead-based paint decontamination, investments aiming at reducing industrial lead emissions and removal of all lead drinking water pipes.</p> <p>Results</p> <p>The following overall annual benefits for the three hypothetical thresholds values in 2008 are: €22.72 billion, €10.72 billion and €0.44 billion, respectively. Costs from abatement ranged from €0.9 billion to 2.95 billion/year. Finally, from a partial CBA of lead control in soils and dust the estimates of total net benefits were € 3.78 billion, € 1.88 billion and €0.25 billion respectively for the three hypothesized B-Pb effect values.</p> <p>Conclusions</p> <p>Prevention of childhood lead exposure has a high social benefit, due to reduction of B-Pb concentrations to levels below 15 μg/L or 24 μg/L, respectively. Reducing only exposures above 100 μg/L B-Pb has little economic impact due to the small number of children who now exhibit such high exposure levels. Prudent public policies would help avoiding future medical interventions, limit the need for special education and increase future productivity, and hence lifetime income for children exposed to lead.</p

Un polymorphisme mendélien sous-jacent aux variations quantitatives de la caséine αs1 caprine

National audienceUsing SDS-polyacrylamide gel electrophoresis and rocket immunoelectrophoresis, 3 new alleles, designated αs1-CnB-,αs1-CnF and αs1-Cno, were identified at the goat αs1-Cn locus, in addition to alleles αs1-CnA, αs1-CnB and αs1-CnC previously reported by BOULANGER al. (1984). Alleles αs1-CnA, αs1-CnB and αs1-CnC are associated with a high content of αs1-casein (approximate mean contribution of each allele being 3.6 g/I) compared to αs1-CnF with a low content (0.6 g/I) and αs1-CnB- with an intermediate content (1.6 g/1) ; αs1-Cno appears to be a true null allele. In a sample of 213 Alpine females from 49 flocks in West Central France, the frequencies of the 6 alleles were : αs1-CnA = 0.14 ; αs1-CnB = 0.05 ; αs1-CnC = 0.01 ; αs1-CnB- = 0.34 ; αs1-CnF = 0.41 ; and αs1-Cno = 0.05. In a sample of 159 Saanen females from 52 flocks of the same region, the frequencies were : αs1-CnA = 0.07 ; αs1-CnB = 0.06 ; αs1-CnC = 0 ; αs1-CnB- = 0.41 ; αs1-CnF = 0.43 ; αs1-Cno = 0.03. Additional data confirm that loci αs1-Cn and αs2-Cn are closely linked. Preliminary investigations indicated a significant superiority in casein content of milks from goats possessing the allele αs1-CnA, as compared to that of milks from goats of genotypes αs1-CnF / αs1-CnF and αs1-CnB- /αs1-CnF and, in a large herd (N = 251), a strong correlation was observed between the αs1-casein content and the rennet-casein content of milk (r = 0.68 ; b = 0.64).A l’aide d’électrophorèses en gel de polyacrylamide SDS et d’immuno-électrophorèses « rocket », 3 allèles, appelés αs1-CnB-, αs1-CnF et αs1-Cno ont été identifiées au locus αs1-Cn de la chèvre, en plus des allèles αs1-CnA, αs1-CnB et αs1-CnC déjà détectés par BOULANGER et al. (1984). Les allèles αs1-CnA, αs1-CnB et αs1-CnC sont associés à un taux élevé de caséine αs1 (contribution approximative de chaque allèle : 3,6 g/I), l’allèle αs1-CnF a un taux faible (0,6 g/I) et l’allèle αs1-CnB a un taux intermédiaire (1,6 g/1). Dans un échantillon de 213 femelles Alpine provenant de 49 troupeaux du centre-ouest de la France, les fréquences des 6 allèles actuellement identifiés étaient les suivantes : αs1-CnA = 0,14 ; αs1-CnB = 0,05 ; αs1-CnC = 0,01; αs1-CnB- = 0,34 ; αs1-CnF = 0,41 et αs1-Cno = 0,05. Dans un échantillon de 159 femelles Saanen provenant de 52 troupeaux de la même région, les fréquences étaient : αs1-CnA = 0,07 ; αs1-CnB = 0,06 ; αs1-CnC = 0; αs1-CnB- = 0,41 ; αs1-CnF = 0,43 ; αs1-Cno = 0,03. Des données supplémentaires confirment que les loci αs1-Cn et αs2-Cn sont étroitement liés. Des investigations préliminaires révèlent que le taux de caséine des laits des chèvres possédant l’allèle αs1-CnA est significativement supérieur à celui des laits des chèvres de génotype αs1-CnF / αs1-CnF ou αs1-CnB- /αs1-CnF; parailleurs, dans un grand troupeau (N = 251), une forte corrélation a été observée entre le taux de caséine αs1 et le taux de matières azotées coagulables (r = 0,68 ; b = 0,64)

Diagnostic echographique d'un syndrome polymalformatif hereditaire: syndrome de Meckel-Gruber ou syndrome de Carpenter-Hunter. [Ultrasonic diagnosis of a hereditary multiple malformation syndrome: Meckel-Gruber syndrome or Carpenter-Hunter syndrome]

Concerned by 2 cases of a recurring multiple fetal malformation syndrome in a consanguineous couple, the authors present the ultrasonic, clinical and paraclinical data that, when introduced into a computerised prenatal diagnostic programme, suggest a Meckel-Gruber or Carpenter-Hunter syndrome. The discovery of single or multiple fetal malformations requires not only complete echographic assessment, but also detailed post-abortum examination to allow optimal use of diagnostic aid programmes

1 -Etude de l'impact sur les crues de l'extension de l'usine de Méry-sur-Oise

Dans le but d’analyser l’impact de l’extension de l’usine de production d’eau potable de Méry-Sur-Oise du syndicat des Eaux d’Ile de France sur la propagation des crues de l ’Oise et sur le maintien de l’inondabilité d’une zone humide située à l ’arrière de l ’usine, une étude hydraulique en régime transitoire a été réalisée à l'aide du logiciel bidimensionnel de calcul de champ de courant et de niveau d’eau REFLUX L ’étude a montré que l’extension de l’usine n ’axait pas d’impact décelable sur le champ d’inondation et que le fossé actuellement en service était suffisant pour assurer le remplissage de la zone humide.Tanguy Jean-Michel, Thery L., Vandevelde T., Brignon J. M., Chagneau G. 1 -Etude de l'impact sur les crues de l'extension de l'usine de Méry-sur-Oise . In: L'école française de l'eau au service du développement mondial. Congrès de la Société Hydrotechnique de France. 25èmes journées de l'hydraulique. Chambéry, du 15 au 18 septembre 1996. Tome 2, 1998

Foetus thoracopages. Diagnostic echographique a 16 semaines. [Thoracopagus fetus. Ultrasonic diagnosis at 16 weeks]

This paper reports the ultrasound diagnosis at 16 weeks' gestation of thoracopagus conjoined twins. Ultrasound examination showed the two fetuses conjoined at the sternum, with a single heart and a single liver. After informing the couple of the extremely poor prognosis, medical termination of pregnancy was requested. Pathologic examination of the conjoined female fetuses revealed a single, non-duplicated heart, two livers connected at the right lobe, completely separate bile ducts and digestive tract, and a single placenta and umbilical cord containing two arteries and six veins. The karyotype was normal. Diagnostic ultrasound criteria for thoracopagus conjoined twins include: the relative position of the two fetuses facing each other, hyperextension of the cervical spine, continuity of the skin and mirror image body parts with limbs close together. The presence of a single heart, liver and umbilical cord, all of increased size, confirms the diagnosis. Various degrees of fetal fusion result from incomplete division of the inner cell mass 13 to 15 days after fertilization. Although the precise causes are unknown, many workers believe that the factors responsible for monozygosity may also play a role in conjoined twins. In Switzerland, 1% of all live births are twins with approximately 1/4 of these monozygotic. If incomplete division of the inner cell mass occurs in 1% of these cases, the estimated incidence of conjoined twins is 1/40000 births. Although thoracopagus twins are more frequent, omphalopagus twins are more commonly encountered at birth, due to lower fetal mortality. The overall prognosis depends on the degree of organ sharing between fetuses. Very few surgically separated thoracopagus conjoined twins have lived and those who did survive had separate hearts. Also, conjoined twins can cause dystocia with the risk of rupture of the uterus, and often require cesarean section which may have negative consequences for the obstetrical future of the mother. However, an early ultrasound diagnostic can modify prognosis and allow medical termination of pregnancy in the case of seriously malformed thoracopagus conjoined twins. The risk that the condition recurs in a subsequent pregnancy may be considered negligible