568 research outputs found
Meaningfulness of design criteria in relation to claw disorder and mortality of fattening bulls
To prove the meaningfulness of design criteria in relation to claw disorder and mortality of fattening bulls a cohort analysis was carried out on 50 farms with housing systems characterised by fully slatted floor, deep litter or litter+concrete floor. Hoofs of the bulls were collected after slaughtering and examined for pathological findings. Space allowance, feeding space, pen depth and quality of the floor were integrated into a TGI-40 protocol and related to the incidence of early losses.
Slatted floor pens were characterised by a low space allowance and a low pen depth. In contrast, dimensions of pens with deep litter and litter+concrete floor were clearly larger but showed a wide and overlapping variation in the different design criteria. Hoofs on animals from deep litter and litter+concrete floor were in a worse condition than hoofs on animals from fully slatted floor. Early and total animal losses were higher in slatted floor than in litter systems. Early losses correlated significantly with the scores of the TGI-40 protocol (r=-0.31). Additionally, the group of the 25% best farms in relation to scores showed a significant lower incidence of early losses compared to the remaining farms. Design criteria integrated into a scores system provide information for the farmer how to reduce the risk for early losses.
(SUNDRUM, A. and I. RUBELOWSKI (2001): Meaningfulness of design criteria in relation to animal health. Acta Agric. Scand., Sect A, Animal Science 30, 48-52.
Application of Celluspots peptide arrays for the analysis of the binding specificity of epigenetic reading domains to modified histone tails
<p>Abstract</p> <p>Background</p> <p>Epigenetic reading domains are involved in the regulation of gene expression and chromatin state by interacting with histones in a post-translational modification specific manner. A detailed knowledge of the target modifications of reading domains, including enhancing and inhibiting secondary modifications, will lead to a better understanding of the biological signaling processes mediated by reading domains.</p> <p>Results</p> <p>We describe the application of Celluspots peptide arrays which contain 384 histone peptides carrying 59 post translational modifications in different combinations as an inexpensive, reliable and fast method for initial screening for specific interactions of reading domains with modified histone peptides. To validate the method, we tested the binding specificities of seven known epigenetic reading domains on Celluspots peptide arrays, viz. the HP1Ă and MPP8 Chromo domains, JMJD2A and 53BP1 Tudor domains, Dnmt3a PWWP domain, Rag2 PHD domain and BRD2 Bromo domain. In general, the binding results agreed with literature data with respect to the primary specificity of the reading domains, but in almost all cases we obtained additional new information concerning the influence of secondary modifications surrounding the target modification.</p> <p>Conclusions</p> <p>We conclude that Celluspots peptide arrays are powerful screening tools for studying the specificity of putative reading domains binding to modified histone peptides.</p
Consistency in Cross-Generational Engineering of Cyber-Physical Systems
Developing CPS is challenging: Cross-domain collaboration and cross-generational design pose fincancial risks for manufacturers, as different engineering models can become inconsistent to each other in the development process. Existing apporaches fail to ensure consistency within and across system generations. Our research addresses this issue by combining mechanical and software engineering approaches. We present a methodology using a brake system research platform to identify challenges and solutions in CPS development. The objective of our research is to formalize changes between generations of CPS and to develop algorithm-based consistency analysis methods. In the long term, we aim to facilitate cross-domain consistency management and create a systematic framework for CPS development
Somatic cancer mutations in the MLL3-SET domain alter the catalytic properties of the enzyme
BACKGROUND:
Somatic mutations in epigenetic enzymes are frequently found in cancer tissues. The MLL3 H3K4-specific protein lysine monomethyltransferase is an important epigenetic enzyme, and it is among the most recurrently mutated enzymes in cancers. MLL3 mainly introduces H3K4me1 at enhancers.
RESULTS:
We investigated the enzymatic properties of MLL3 variants that carry somatic cancer mutations. Asn4848 is located at the cofactor binding sites, and the N4848S exchange renders the enzyme inactive. Tyr4884 is part of an aromatic pocket at the active center of the enzyme, and Y4884C converts MLL3 from a monomethyltransferase with substrate preference for H3K4me0 to a trimethyltransferase with H3K4me1 as preferred substrate. Expression of Y4884C leads to aberrant H3K4me3 formation in cells.
CONCLUSIONS:
Our data show that different somatic cancer mutations of MLL3 affect the enzyme activity in distinct and opposing manner highlighting the importance of experimentally studying the effects of somatic cancer mutations in key regulatory enzymes in order to develop and apply targeted tumor therapy
EARLINET: towards an advanced sustainable European aerosol lidar network
The European Aerosol Research Lidar Network, EARLINET, was founded in 2000 as a research project for establishing a quantitative, comprehensive, and statistically significant database for the horizontal, vertical, and temporal distribution of aerosols on a continental scale. Since then EARLINET has continued to provide the most extensive collection of ground-based data for the aerosol vertical distribution over Europe.
This paper gives an overview of the network's main developments since 2000 and introduces the dedicated EARLINET special issue, which reports on the present innovative and comprehensive technical solutions and scientific results related to the use of advanced lidar remote sensing techniques for the study of aerosol properties as developed within the network in the last 13 years.
Since 2000, EARLINET has developed greatly in terms of number of stations and spatial distribution: from 17 stations in 10 countries in 2000 to 27 stations in 16 countries in 2013. EARLINET has developed greatly also in terms of technological advances with the spread of advanced multiwavelength Raman lidar stations in Europe. The developments for the quality assurance strategy, the optimization of instruments and data processing, and the dissemination of data have contributed to a significant improvement of the network towards a more sustainable observing system, with an increase in the observing capability and a reduction of operational costs.
Consequently, EARLINET data have already been extensively used for many climatological studies, long-range transport events, Saharan dust outbreaks, plumes from volcanic eruptions, and for model evaluation and satellite data validation and integration.
Future plans are aimed at continuous measurements and near-real-time data delivery in close cooperation with other ground-based networks, such as in the ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) www.actris.net, and with the modeling and satellite community, linking the research community with the operational world, with the aim of establishing of the atmospheric part of the European component of the integrated global observing system.Peer ReviewedPostprint (published version
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Saharan Mineral Dust Experiments SAMUM-1 and SAMUM-2: What have we learned?
Two comprehensive field campaigns were conducted in 2006 and 2008 in the framework of the Saharan Mineral Dust Experiment (SAMUM) project. The relationship between chemical composition, shape morphology, size distribution and optical effects of the dust particles was investigated. The impact of Saharan dust on radiative transfer and the feedback of radiative effects upon dust emission and aerosol transport were studied. Field observations (ground-based, airborne and remote sensing) and modelling results were compared within a variety of dust closure experiments with a strong focus on vertical profiling. For the first time, multiwavelength Raman/polarization lidars and an airborne high spectral resolution lidar were involved in major dust field campaigns and provided profiles of the volume extinction coefficient of the particles at ambient conditions (for the full dust size distribution), of particle-shape-sensitive optical properties at several wavelengths, and a clear separation of dust and smoke profiles allowing for an estimation of the single-scattering albedo of the biomass-burning aerosol. SAMUMâ1 took place in southern Morocco close to the Saharan desert in the summer of 2006, whereas SAMUMâ2 was conducted in Cape Verde in the outflow region of desert dust and biomass-burning smoke from western Africa in the winter of 2008. This paper gives an overview of the SAMUM concept, strategy and goals, provides snapshots (highlights) of SAMUMâ2 observations and modelling efforts, summarizes main findings of SAMUMâ1 and SAMUMâ2 and finally presents a list of remaining problems and unsolved questions
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Arctic haze over Central Europe
An extraordinary aerosol situation over Leipzig, Germany in April 2002 was investigated with a comprehensive
set of ground-based volumetric and columnar aerosol data, combined with aerosol profiles
from lidar, meteorological data from radiosondes and air mass trajectory calculations. Air masses
were identified to stem from the Arctic, partly influenced by the greater Moscow region. An evaluation
of ground-based measurements of aerosol size distributions during these periods showed that
the number concentrations below about 70 nm in diameter were below respective long-term average
data, while number, surface and volume concentrations of the particles larger than about 70 nm in
diameter were higher than the long-term averages. The lidar aerosol profiles showed that the imported
aerosol particles were present up to about 3 km altitude. The particle optical depth was up to 0.45 at
550 nm wavelength. With a one-dimensional spectral radiative transfer model top of the atmosphere
(TOA) radiative forcing of the aerosol layer was estimated for a period with detailed vertical information.
Solar aerosol radiative forcing values between â23 and â38 W mâ2 were calculated, which are
comparable to values that have been reported in heavily polluted continental plumes outside the respective
source regions. The present report adds weight to previous findings of aerosol import to Europe,
pointing to the need for attributing the three-dimensional aerosol burden to natural and anthropogenic
sources as well as to aerosol imports from adjacent or distant source regions. In the present case, the
transport situation is further complicated by forward trajectories, indicating that some of the observed
Arctic haze may have originated in Central Europe. This aerosolwas transported to the European Arctic
before being re-imported in the modified and augmented form to its initial source region
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Vertical profiling of Saharan dust with Raman lidars and airborne HSRL in southern Morocco during SAMUM
Three ground-based Raman lidars and an airborne high-spectral-resolution lidar (HSRL) were operated duringSAMUM 2006 in southern Morocco to measure height profiles of the volume extinction coefficient, the extinction-to-backscatter ratio and the depolarization ratio of dust particles in the Saharan dust layer at several wavelengths. Aerosol Robotic Network (AERONET) Sun photometer observations and radiosoundings of meteorological parameters complemented the ground-based activities at the SAMUM station of Ouarzazate. Four case studies are presented. Two case studies deal with the comparison of observations of the three ground-based lidars during a heavy dust outbreak and of the ground-based lidars with the airborne lidar. Two further cases show profile observations during satellite overpasses on 19 May and 4 June 2006. The height resolved statistical analysis reveals that the dust layer top typically reaches 4â6 km height above sea level (a.s.l.), sometimes even 7 km a.s.l.. Usually, a vertically inhomogeneous dust plume with internal dust layers was observed in the morning before the evolution of the boundary layer started. The Saharan dust layer was well mixed in the early evening. The 500 nm dust optical depth ranged from 0.2â0.8 at the field site south of the High Atlas mountains, Ă
ngström exponents derived from photometer and lidar data were between 0â0.4. The volume extinction coefficients (355, 532 nm) varied from 30â300Mmâ1 with a mean value of 100Mmâ1 in the lowest 4 km a.s.l.. On average, extinction-to-backscatter ratios of 53â55 sr (±7â13 sr) were obtained at 355, 532 and 1064 nm
The implementation of dust mineralogy in COSMO5.05-MUSCAT
Mineral dust aerosols are composed of a complex assemblage of various minerals depending on the region in which they originated. Given the different mineral composition of desert dust aerosols, different physicochemical properties and therefore varying climate effects are expected.
Despite the known regional variations in mineral composition, chemical transport models typically assume that mineral dust aerosols have uniform composition. This study adds, for the first time, mineralogical information to the mineral dust emission scheme used in the chemical transport model COSMOâMUSCAT. We provide a detailed description of the implementation of the mineralogical database, GMINER (Nickovic et al., 2012), together with a specific set of physical parameterizations in the model's mineral dust emission module, which led to a general improvement of the model performance when comparing the simulated mineral dust aerosols with measurements over the Sahara region for JanuaryâFebruary 2022.
The simulated mineral dust aerosol vertical distribution is tested by a comparison with aerosol lidar measurements from the lidar system PollyXT, located at Cape Verde. For a lofted mineral dust aerosol layer on 2 February at 05:00âUTC the lidar retrievals yield a dust mass concentration peak of 156â”gâmâ3, while the model calculates the mineral dust peak at 136â”gâmâ3. The results highlight the possibility of using the model with resolved mineral dust composition for interpretation of the lidar measurements since a higher absorption in the UVâVis wavelengths is correlated with particles having a higher hematite content. Additionally, the comparison with in situ mineralogical measurements of dust aerosol particles shows that more of them are needed for model evaluation
The automated multiwavelength Raman polarization and water-vapor lidar PollyXT: The neXT generation
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 120âŻm above ground, a water-vapor channel, and channels for simultaneous measurements of the particle linear depolarization ratio at 355 and 532âŻnm. 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 24â7 monitoring of the atmospheric state with PollyXT
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