85 research outputs found
Monitoring of the Eyjafjalla volcanic plume at four lidar stations over the Iberian Peninsula: 6 to 8 May 2010
Lidar measurements were performed in the
framework of the EARLINET and SPALINET networks
during the eruption of Eyjafjalla volcano (Iceland) since 14
April 2010. The profiles of the aerosol optical properties,
namely backscatter and extinction coefficients, lidar ratio and
Angström exponent, show the presence of volcanic aerosol
layers over all SPALINET stations since 5 May. The volcanic
particles were monitored both within the planetary boundary
layer and in decoupled layers up to 8 km agl over the Iberian
Peninsula. This is the first time that the spatial and temporal
distributions of volcanic aerosols have been studied with active
remote sensing techniques over the Iberian Peninsula.Postprint (published version
Monoclonal antibodies biosimilarity assessment using transient isotachophoresis capillary zone electrophoresis-tandem mass spectrometry
Out of all categories, monoclonal antibody (mAb) therapeutics attract the most interest due to their strong therapeutic potency and specificity. Six of the ten top-selling drugs are antibody-based therapeutics that will lose patent protection soon. The European Medicines Agency has pioneered the regulatory framework for approval of biosimilar products and approved the first biosimilar antibodies by the end of 2013. As highly complex glycoproteins with a wide range of micro-variants, mAbs require extensive characterization through multiple analytical methods for structure assessment rendering manufacturing control and biosimilarity studies particularly product and time-consuming. Here, capillary zone electrophoresis coupled to mass spectrometry by a sheathless interface (CESI-MS) was used to characterize marketed reference mAbs and their respective biosimilar candidate simultaneously over different facets of their primary structure. CESI-MS/MS data were compared between approved mAbs and their biosimilar candidates to prove/disconfirm biosimilarity regarding recent regulation directives. Using only a single sample injection of 200 fmol, CESI-MS/MS data enabled 100% amino acids (AA) sequence characterization, which allows a difference of even one AA between two samples to be distinguished precisely. Simultaneously glycoforms were characterized regarding their structures and position through fragmentation spectra and glycoforms semiquantitative analysis was established, showing the capacity of the developed methodology to detect up to 16 different glycans. Other posttranslational modifications hotspots were characterized while their relative occurrence levels were estimated and compared to biosimilars. These results proved the value of using CESI-MS because the separation selectivity and ionization efficiency provided by the system allowed substantial improvement in the characterization workflow robustness and accuracy. Biosimilarity assessment could be performed routinely with a single injection of each candidate enabling improvements in the biosimilar development pipeline
G1-arrested newborn cells are the predominant infectious form of the pathogen Brucella abortus
Several intracellular pathogens, such as Brucella abortus, display a biphasic infection process starting with a non-proliferative stage of unclear nature. Here, we study the cell cycle of B. abortus at the single-cell level, in culture and during infection of HeLa cells and macrophages. The localization of segregation and replication loci of the two bacterial chromosomes indicates that, immediately after being engulfed by host-cell endocytic vacuoles, most bacterial cells are newborn. These bacterial cells do not initiate DNA replication for the next 4 to 6 h, indicating a G1 arrest. Moreover, growth is completely stopped during that time, reflecting a global cell cycle block. Growth and DNA replication resume later, although bacteria still reside within endosomal-like compartments. We hypothesize that the predominance of G1-arrested bacteria in the infectious population, and the bacterial cell cycle arrest following internalization, may constitute a widespread strategy among intracellular pathogens to colonize new proliferation niches
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Lidar-Radiometer Inversion Code (LIRIC) for the retrieval of vertical aerosol properties from combined lidar/radiometer data: Development and distribution in EARLINET
This paper presents a detailed description of LIRIC (LIdar-Radiometer Inversion Code) algorithm for simultaneous processing of coincident lidar and radiometric (sun photometric) observations for the retrieval of the aerosol concentration vertical profiles. As the lidar/radiometric input data we use measurements from European Aerosol Research Lidar Network (EARLINET) lidars and collocated sun-photometers of Aerosol Robotic Network (AERONET). The LIRIC data processing provides sequential inversion of the combined lidar and radiometric data. The algorithm starts with the estimations of column-integrated aerosol parameters from radiometric measurements followed by the retrieval of height dependent concentrations of fine and coarse aerosols from lidar signals using integrated column characteristics of aerosol layer as a priori constraints. The use of polarized lidar observations allows us to discriminate between spherical and non-spherical particles of the coarse aerosol mode.
The LIRIC software package was implemented and tested at a number of EARLINET stations. Intercomparison of the LIRIC-based aerosol retrievals was performed for the observations by seven EARLINET lidars in Leipzig, Germany on 25 May 2009. We found close agreement between the aerosol parameters derived from different lidars that supports high robustness of the LIRIC algorithm. The sensitivity of the retrieval results to the possible reduction of the available observation data is also discussed
Lidar-Radiometer Inversion Code (LIRIC) for the retrieval of vertical aerosol properties from combined lidar/radiometer data: development and distribution in EARLINET
The financial support by the European Union's Horizon 2020 research and innovation programme (ACTRIS-2, grant agreement no. 654109) is gratefully acknowledged. The background of LIRIC algorithm and software was developed under the ACTRIS Research Infrastructure project, grant agreement no. 262254, within the European Union Seventh Framework Programme, which financial support is gratefully acknowledged.r I. Binietoglou received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under the grant agreement no. 289923 - ITARS.This paper presents a detailed description of
LIRIC (LIdar-Radiometer Inversion Code) algorithm for simultaneous processing of coincident lidar and radiometric
(sun photometric) observations for the retrieval of the aerosol
concentration vertical profiles. As the lidar/radiometric input data we use measurements from European Aerosol Research Lidar Network (EARLINET) lidars and collocated
sun-photometers of Aerosol Robotic Network (AERONET).
The LIRIC data processing provides sequential inversion of
the combined lidar and radiometric data. The algorithm starts
with the estimations of column-integrated aerosol parameters
from radiometric measurements followed by the retrieval of
height dependent concentrations of fine and coarse aerosols
from lidar signals using integrated column characteristics of aerosol layer as a priori constraints. The use of polarized lidar observations allows us to discriminate between spherical
and non-spherical particles of the coarse aerosol mode.
The LIRIC software package was implemented and tested
at a number of EARLINET stations. Intercomparison of the
LIRIC-based aerosol retrievals was performed for the observations by seven EARLINET lidars in Leipzig, Germany on
25 May 2009. We found close agreement between the aerosol
parameters derived from different lidars that supports high
robustness of the LIRIC algorithm. The sensitivity of the retrieval results to the possible reduction of the available observation data is also discussed.European Union (EU)
654109ACTRIS Research Infrastructure project within the European Union
262254European Union (EU)
289923 - ITAR
Gene duplication and phenotypic changes in the evolution of Mammalian metabolic networks
Metabolic networks attempt to describe the complete suite of biochemical reactions available to an organism. One notable feature of these networks in mammals is the large number of distinct proteins that catalyze the same reaction. While the existence of these isoenzymes has long been known, their evolutionary significance is still unclear. Using a phylogenetically-aware comparative genomics approach, we infer enzyme orthology networks for sixteen mammals as well as for their common ancestors. We find that the pattern of isoenzymes copy-number alterations (CNAs) in these networks is suggestive of natural selection acting on the retention of certain gene duplications. When further analyzing these data with a machine-learning approach, we found that that the pattern of CNAs is also predictive of several important phenotypic traits, including milk composition and geographic range. Integrating tools from network analyses, phylogenetics and comparative genomics both allows the prediction of phenotypes from genetic data and represents a means of unifying distinct biological disciplines
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EARLINET instrument intercomparison campaigns: Overview on strategy and results
This paper introduces the recent European Aerosol Research Lidar Network (EARLINET) quality-assurance efforts at instrument level. Within two dedicated campaigns and five single-site intercomparison activities, 21 EARLINET systems from 18 EARLINET stations were intercompared between 2009 and 2013. A comprehensive strategy for campaign setup and data evaluation has been established. Eleven systems from nine EARLINET stations participated in the EARLINET Lidar Intercomparison 2009 (EARLI09). In this campaign, three reference systems were qualified which served as traveling standards thereafter. EARLINET systems from nine other stations have been compared against these reference systems since 2009. We present and discuss comparisons at signal and at product level from all campaigns for more than 100 individual measurement channels at the wavelengths of 355, 387, 532, and 607 nm. It is shown that in most cases, a very good agreement of the compared systems with the respective reference is obtained. Mean signal deviations in predefined height ranges are typically below ±2 %. Particle backscatter and extinction coefficients agree within ±2  ×  10−4 km−1 sr−1 and ± 0.01 km−1, respectively, in most cases. For systems or channels that showed larger discrepancies, an in-depth analysis of deficiencies was performed and technical solutions and upgrades were proposed and realized. The intercomparisons have reinforced confidence in the EARLINET data quality and allowed us to draw conclusions on necessary system improvements for some instruments and to identify major challenges that need to be tackled in the future
Selection for Higher Gene Copy Number after Different Types of Plant Gene Duplications
The evolutionary origins of the multitude of duplicate genes in the plant genomes are still incompletely understood. To gain an appreciation of the potential selective forces acting on these duplicates, we phylogenetically inferred the set of metabolic gene families from 10 flowering plant (angiosperm) genomes. We then compared the metabolic fluxes for these families, predicted using the Arabidopsis thaliana and Sorghum bicolor metabolic networks, with the families' duplication propensities. For duplications produced by both small scale (small-scale duplications) and genome duplication (whole-genome duplications), there is a significant association between the flux and the tendency to duplicate. Following this global analysis, we made a more fine-scale study of the selective constraints observed on plant sodium and phosphate transporters. We find that the different duplication mechanisms give rise to differing selective constraints. However, the exact nature of this pattern varies between the gene families, and we argue that the duplication mechanism alone does not define a duplicated gene's subsequent evolutionary trajectory. Collectively, our results argue for the interplay of history, function, and selection in shaping the duplicate gene evolution in plants
Study on aerosol properties over Madrid (Spain) by multiple instrumentation during SPALI10 lidar campaign
Understanding the effect of aerosols upon radiative forcing requ
ires information about vertical profiles. Lidar techniques
represent a powerful tool for studies of the vertical structure
of the aerosol field. During the SPAin Lidar Intercomparison 20
10 (SPALI10) campaign, several multiwavelen
gth Raman lidar systems measured simultaneously in order to assess their performances. Multiwavelength lidars can pr
ovide relevant vertically-resolved information on aerosol optical
properties because the wavelength dependence of the backscatter and extinction coefficients allows for a more detailed discrimination of aerosol types. Several lidar stations belonging to SPALINET, the Spanish and Portuguese Lidar NETwork and also EARLINET, the European Aerosol Research Lidar NETwork, intercompared during a campaign that took place in Madrid from 18 October to 5 November 2010. The products provided by the lidar systems were compared with ancillary data.
At ground level, aerosol size distribution was continuously monitored. Additionally, the column-integrated characterization of the atmospheric aerosol was performed by means of a sun photometer. The extensive dataset obtained during SPALI10 field campaign enables to compare ground-level in-situ measurements with remote sensing techniques to determine vertically-resolved optical and microphysical properties of aerosols. Several relevant features shown in the comparison of the results obtained by the different instruments
are discussed in this work.Peer ReviewedPostprint (published version
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