Sensitivity enhancement by increasing the nonlinear crystal length in second-order autocorrelators for ultrashort laser pulses measurement

A theoretical model for interferometric autocorrelation with long nonlinear crystal (input depleted) has been developed and applied to the measurement of the duration of ultrashort pulses. The phase-matching condition is assumed throughout pulse spectrum. The interferometric autocorrelation trace of a mode-locked fibre laser (20 nJ energy, 100 kW peak power, centred at 1595 nm) has been measured by employing a fibre interferometer to avoid misalignment effects and a BBO nonlinear crystal as long as 2 mm, in order to generate higher second-harmonic power. BBO crystal was used because it can keep the phase-matching condition throughout a wide spectrum around 1600 nm. By fitting the experimental measurements and computing according to the theoretical model exposed, it has been demonstrated that the autocorrelator sensitivity is clearly enhanced by increasing the nonlinear crystal length. A temporal duration of 0.18 ps has been obtained by fitting theoretical and experimental values

Diagenesis, carbonate cementation and resevoir quality evolution of Eocene deep-water marine turbidite sandstones of the Hecho Group, South-Central Pyrenees

Sandstone turbidites from the Hecho Group in the South-Central Pyrenees are considered exceptional examples for reservoir modelling and outcrop analogous studies. The Hecho Group is divided into four major tectosedimentary units (TSU-2 to TSU-5) and the sandstone composition varies from quartzarenites to arkoses (TSU-2), lithoarenites to hybrid arenites (TSU-3 and TSU-4), and hybrid arenites (rich in carbonate bioclasts; TSU-5). In TSU-2, the lowermost and most deformed unit, calcite cement precipitation was related to tectonic deformation. In the other turbidite systems (TSU-3, 4 and 5) eodiagenesis is evidenced by precipitation of dolomite cement and pyrite, which are locally abundant in all sandstones. Overall, compaction was more important than cementation in destroying porosity. However, the precipitation of dolomite overgrowth and intragranular mesogenetic ferroan calcite occluded nearly completely the remaining porosity and halted further compaction. Dissolution of calcite and dolomite cements has resulted in creation of minor amounts of secondary porosity

Peritoneal tuberculosis due to Mycobacterium caprae

The incidence of tuberculosis in humans due to Mycobacterium caprae is very low and is almost confined to Europe. We report a case of a previously healthy 41-year-old Moroccan with a 6 month history of abdominal pain, weight loss, fatigue and diarrhea. A diagnosis of peritoneal tuberculosis due to M. caprae was mad

Analysis of different ventilation strategies and CO2 distribution in a naturally ventilated classroom

CO2 monitoring has proven to be an effective and affordable way of controlling air ventilation rates, a paramount task for minimizing airborne contagions in indoor shared spaces. In this work, the CO2 distribution in a naturally-ventilated classroom has been thoroughly characterized, gaining information not only on the effectiveness of diverse ventilation strategies but also on the expected differences between CO2 values when varying the sampling location within the room. The results confirm that an adequate renewal of the air in the room requires the use of cross-ventilation, with openings in different walls. Furthermore, it was found that ventilation is optimized, for a given total opening area, when the openings are distributed as much as possible among different windows. For most of the studied conditions, a global windows opening area of 1.24 m2 with an open door was typically enough to yield CO2 concentrations below 700 ppm. The CO2 readings displayed a noticeable and consistent dependency on the sampling height, with below-average values at 0.75 m, the highest concentrations at 1.5 m, and levels close to the average when sampling at a height of 2.2 m. For a given height, the influence of the sampling location within the room was weaker, and more dependent on the specific ventilation strategy applied. However, the tests consistently showed CO2 records significantly lower for sensors installed on the walls. Besides a detailed spatial and temporal characterization of the ventilation process under different ventilation strategies, these results are thought to provide useful and novel information for a judicious placement of CO2 monitoring systems

Diagenetic Evolution and Porosity Destruction of Turbiditic Hybrid Arenites and Siliciclastic Sandstones of Foreland Basins: Evidence from the Eocene Hecho Group, Pyrenees, Spain

International audienceThis study aims to unravel the impact of diagenetic alterations on porosity loss of foreland-basin turbiditic hybrid arenites and associated siliciclastic sandstones of the Eocene Hecho Group (south-central Pyrenees, Spain). In this succession, hybrid arenites and calclithites are extensively cemented by mesogenetic calcite cement (delta18O VPDB = –10.0 per thousand to –5.8per thousand ; Th, mode = 80° C; salinity mode = 18.8 wt% eq. NaCl), Fe-dolomite (delta18O VPDB = –8.5 per thousand to –6.3 per thousand ) and trace amounts of siderite. The extent of carbonate cementation is interpreted to be related to the amounts of extrabasinal and intrabasinal carbonate grains, which provided nuclei and sources for the precipitation and growth of carbonate cements. Other diagenetic alterations, such as pyrite and albitization, had no impact on reservoir quality. Scarce early diagenetic cements, coupled with abundant ductile carbonate and siliciclastic framework grains, have led to rapid porosity loss owing to compaction. Conversely, abundant quartz in the sandstones prevented rapid loss of porosity by mechanical compaction. Reservoir quality was affected by mesogenetic cementation by quartz overgrowths, calcite and dolomite intergranular pressure dissolution of quartz grains, and formation of fracture-filling calcite cement (delta 18O V-PDB values from –10.4 per thousand to –7.8 per thousand ; Th temperatures of circa 150° C), which are attributed to deep circulation of hot meteoric waters during extensional stages of tectonism. The results of this study illustrate that diagenetic evolution pathways of the arenites and sandstones are closely linked to the variation in detrital composition, particularly the proportion and types of extrabasinal noncarbonates, extrabasinal carbonates, and intrabasinal carbonate grains. These insights suggest that marine turbiditic hybrid arenites and calclithites of foreland basins are subjected to more rapid and extensive porosity loss owing to compaction and cementation than associated siliciclastic sandstones. Degradation of reservoir quality makes these hybrid arenites, calclithites, and sandstones suitable as tight gas reservoirs, but only if fracture porosity and permeability develop during tectonic deformation

Digital in-line holography with a spatially partially coherent beam

We propose in this paper an analytical solution to the problem of scalar diffraction of a partially coherent beam by an opaque disk. This analytical solution is applied in digital in-line holography of particles. We demonstrate that the reconstruction by means of fractional Fourier transformation is still possible when a spatially partially coherent beam is used. Numerical simulations and experiments have been carried out

Variabilidad en la composición y procedencia de las areniscas turbidíticas del Grupo Hecho (Pirineo Sur-Central)

The Eocene turbidite systems of the Hecho Croup (tectosedimentary units, TSU-2, 3, 4 and 5) of the Ainsa-Jaca foreland basin (South-Central Pyrenees) are characterised by spectacular outcrops and good preservation of the original field relationships between the fluvio-deltaic, shelf deposits and turbidites. The aim of this work is the petrographic characterisation of turbiditic carbonate are- nites in order to unravel provenance signatures and their evolution. Ternary compositional diagrams based on carbonate grains types, allow us the recognition of a maturity trend in the Hecho Croup turbidites. The lowermost turbidite system, TSU-2, presents the highest abundance in quartz grains and the lowest quantity in carbonate grains, both extra- and intra-basinal. Toward the top, in TSU- 5, quartz abundance decrease and conversely carbonate grains increase. Non-carbonate rock fragments indicate the dominance of low- and medium-rank metamorphic source rocks toward the uppermost TSU-5. In addition, back scattering electron imaging on feldspar grains, confirm the presence of granites, gneisses and metamorphic rocks in the source area. Thus, the obtained results reflects the exposition and erosion of the Pyrenean crystalline basement (granites, gneisses and metamorphic rocks) and its progressive replacement as source rock by carbonate rocks from the thrust-folds belt, due to tectonism evolution and sea-level variations

Ultrastructural, cytogenetic, and molecular findings in mast cell leukemia : Case report

We report a de novo aleukemic form of MCL with a complex monosomic karyotype with LOH for multiple chromosomes and TP53 mutation. Additionally, whereas D816V KIT was not found, the c-Kit transmembrane domain p.M541L variant was detected which is the most common SNP of KIT gene in humans with controversial pathogenic role. In these cases, it is crucial to perform a rapid broad molecular study for an accurate diagnosis which could help to initiate targeted therapy

Sub-Optimal Vitamin B-12 Levels among ART-Naïve HIV-Positive Individuals in an Urban Cohort in Uganda

Malnutrition is common among HIV-infected individuals and is often accompanied by low serum levels of micronutrients. Vitamin B-12 deficiency has been associated with various factors including faster HIV disease progression and CD4 depletion in resource-rich settings. To describe prevalence and factors associated with sub-optimal vitamin B-12 levels among HIV-infected antiretroviral therapy (ART) naïve adults in a resource-poor setting, we performed a cross-sectional study with a retrospective chart review among individuals attending either the Mulago-Mbarara teaching hospitals’ Joint AIDS Program (MJAP) or the Infectious Diseases Institute (IDI) clinics, in Kampala, Uganda. Logistic regression was used to determine factors associated with sub-optimal vitamin B-12. The mean vitamin B-12 level was 384 pg/ml, normal range (200–900). Sub-optimal vitamin B-12 levels (<300 pg/ml) were found in 75/204 (36.8%). Twenty-one of 204 (10.3%) had vitamin B-12 deficiency (<200 pg/ml) while 54/204 (26.5%) had marginal depletion (200–300 pg/ml). Irritable mood was observed more among individuals with sub-optimal vitamin B-12 levels (OR 2.5, 95% CI; 1.1–5.6, P = 0.03). Increasing MCV was associated with decreasing serum B-12 category; 86.9 fl (±5.1) vs. 83 fl (±8.4) vs. 82 fl (±8.4) for B-12 deficiency, marginal and normal B-12 categories respectively (test for trend, P = 0.017). Compared to normal B-12, individuals with vitamin B-12 deficiency had a longer known duration of HIV infection: 42.2 months (±27.1) vs. 29.4 months (±23.8; P = 0.02). Participants eligible for ART (CD4<350 cells/µl) with sub-optimal B-12 had a higher mean rate of CD4 decline compared to counterparts with normal B-12; 118 (±145) vs. 22 (±115) cells/µl/year, P = 0.01 respectively. The prevalence of a sub-optimal vitamin B-12 was high in this HIV-infected, ART-naïve adult clinic population in urban Uganda. We recommend prospective studies to further clarify the causal relationships of sub-optimal vitamin B-12, and explore the role of vitamin B-12 supplementation in immune recovery