284 research outputs found

    Optimization of femtosecond laser processing in liquids

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    In this paper we analyze femtosecond laser processing of metals in liquids searching for optimal conditions for predictable ablation. Incident laser pulses are stretched or compressed, self-focused and scattered on bubbles and on surface waves in the liquid environment. Influence of these effects on the laser intensity distribution on the target surface is discussed and optimal processing parameters are suggested

    Swine zoonosis risk assessment with new herd seroprofiling assays from QIAGEN

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    QIAGEN Leipzig developed the pigtype product line of ELISA tests for screening for swine zoonoses. This product line now includes ELISA for detection of salmonella-, Yersinia-, Trichinella-, and Toxoplasma-antibodies in swine. These pigtype assays are validated for serum and meat juice samples and are officially approved by the German Friedrich-Loeffler-Institut

    5 Years After Tragedy: An Update on Organ Procurement Travel in Michigan

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100335/1/ajt12399.pd

    Profiling of Saharan dust from the Caribbean to western Africa - Part 1: Layering structures and optical properties from shipborne polarization/Raman lidar observations

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    We present final and quality-assured results of multiwavelength polarization/Raman lidar observations of the Saharan air layer (SAL) over the tropical Atlantic. Observations were performed aboard the German research vessel R/V Meteor during the 1-month transatlantic cruise from Guadeloupe to Cabo Verde over 4500 km from 61.5 to 20 degrees W at 14-15 degrees N in April-May 2013. First results of the ship-borne lidar measurements, conducted in the framework of SALTRACE (Saharan Aerosol Long-range Transport and Aerosol-Cloud Interaction Experiment), were reported by Kanitz et al. (2014). Here, we present four observational cases representing key stages of the SAL evolution between Africa and the Caribbean in detail in terms of layering structures and optical properties of the mixture of predominantly dust and aged smoke in the SAL. We discuss to what extent the lidar results confirm the validity of the SAL conceptual model which describes the dust long-range transport and removal processes over the tropical Atlantic. Our observations of a clean marine aerosol layer (MAL, layer from the surface to the SAL base) confirm the conceptual model and suggest that the removal of dust from the MAL, below the SAL, is very efficient. However, the removal of dust from the SAL assumed in the conceptual model to be caused by gravitational settling in combination with large-scale subsidence is weaker than expected. To explain the observed homogenous (height-independent) dust optical properties from the SAL base to the SAL top, from the African coast to the Caribbean, we have to assume that the particle sedimentation strength is reduced and dust vertical mixing and upward transport mechanisms must be active in the SAL. Based on lidar observations on 20 nights at different longitudes in May 2013, we found, on average, MAL and SAL layer mean values (at 532 nm) of the extinction-to-backscatter ratio (lidar ratio) of 17 +/- 5 sr (MAL) and 43 +/- 8 sr (SAL), of the particle linear depolarization ratio of 0.025 +/- 0 : 015 (MAL) and 0.19 +/- 0.09 (SAL), and of the particle extinction coefficient of 67 +/- 45Mm(-1) (MAL) and 68 +/- 37Mm(-1) (SAL). The 532 nm optical depth of the lofted SAL was found to be, on average, 0.15 +/- 0.13 during the ship cruise. The comparably low values of the SAL mean lidar ratio and depolarization ratio (compared to typical pure dust values of 50-60 sr and 0.3, respectively) in combination with backward trajectories indicate a smoke contribution to light extinction of the order of 20% during May 2013, at the end of the burning season in central-western Africa

    Exposure to active and passive smoking during pregnancy and severe small for gestational age at term

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    Objective. The objective of this study was to assess the relationship between active smoking as well as environmental tobacco smoke (ETS) exposure and severe small for gestational age (SGA) at term in a sample of pregnant Italian women. Methods. A case-control study was conducted in nine cities in Italy between October 1999 and September 2000. Cases of severe SGA were singleton, live born, at term children with a birth weight5th percentile for gestational age. Controls (10:1 to cases) were enrolled from among singleton at term births that occurred in the same hospitals one or two days after delivery of the case, with a birth weight10th percentile for gestational age. A total of 84 cases of severe SGA and 858 controls were analyzed. A self-administered questionnaire was used to assess active smoking and ETS exposure, as well as potential confounders. Results. Multivariate logistic regression analysis showed a relationship between active smoking during pregnancy and severe SGA (adjusted odds ratio (OR) 2.10, 95% confidence interval (CI) 1.13-3.68). ETS exposure was associated with severe SGA (adjusted OR 2.51, 95% CI 1.59-3.95) with a dose-response relationship to the number of smokers in the home

    The automated multiwavelength Raman polarization and water-vapor lidar PollyXT: The neXT generation

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    The atmospheric science community demands autonomous and quality-assured vertically resolved measurements of aerosol and cloud properties. For this purpose, a portable lidar called Polly was developed at TROPOS in 2003. The lidar system was continuously improved with gained experience from the EARLINET community, involvement in worldwide field campaigns, and international institute collaborations within the last 10 years. Here we present recent changes of the setup of the portable multiwavelength Raman and polarization lidar PollyXT and discuss the improved capabilities of the system by means of a case study. The latest system developments include an additional near-range receiver unit for Raman measurements of the backscatter and extinction coefficient down to 120 m above ground, a water-vapor channel, and channels for simultaneous measurements of the particle linear depolarization ratio at 355 and 532 nm. Quality improvements were achieved by systematically following the EARLINET guidelines and the international PollyNET quality assurance developments. A modified ship radar ensures measurements in agreement with air-traffic safety regulations and allows for 24∕7 monitoring of the atmospheric state with PollyXT

    An overview of the first decade of PollyNET : an emerging network of automated Raman-polarization lidars for continuous aerosol profiling

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    © Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 LicenseA global vertically resolved aerosol data set covering more than 10 years of observations at more than 20 measurement sites distributed from 63° N to 52° S and 72° W to 124° E has been achieved within the Raman and polarization lidar network PollyNET. This network consists of portable, remote-controlled multiwavelength-polarization-Raman lidars (Polly) for automated and continuous 24/7 observations of clouds and aerosols. PollyNET is an independent, voluntary, and scientific network. All Polly lidars feature a standardized instrument design with different capabilities ranging from single wavelength to multiwavelength systems, and now apply unified calibration, quality control, and data analysis. The observations are processed in near-real time without manual intervention, and are presented online at http://polly.tropos.de/. The paper gives an overview of the observations on four continents and two research vessels obtained with eight Polly systems. The specific aerosol types at these locations (mineral dust, smoke, dust-smoke and other dusty mixtures, urban haze, and volcanic ash) are identified by their Ångström exponent, lidar ratio, and depolarization ratio. The vertical aerosol distribution at the PollyNET locations is discussed on the basis of more than 55 000 automatically retrieved 30 min particle backscatter coefficient profiles at 532 nm as this operating wavelength is available for all Polly lidar systems. A seasonal analysis of measurements at selected sites revealed typical and extraordinary aerosol conditions as well as seasonal differences. These studies show the potential of PollyNET to support the establishment of a global aerosol climatology that covers the entire troposphere.Peer reviewe
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