92 research outputs found
Spatial variability in snow precipitation and accumulation in COSMO–WRF simulations and radar estimations over complex terrain
Snow distribution in complex alpine terrain and its evolution in
the future climate is important in a variety of applications including
hydropower, avalanche forecasting and freshwater resources. However, it is
still challenging to quantitatively forecast precipitation, especially over
complex terrain where the interaction between local wind and precipitation
fields strongly affects snow distribution at the mountain ridge scale.
Therefore, it is essential to retrieve high-resolution information about
precipitation processes over complex terrain. Here, we present very-high-resolution Weather Research and Forecasting model (WRF) simulations
(COSMO–WRF), which are initialized by 2.2 km resolution Consortium for
Small-scale Modeling (COSMO) analysis. To assess the ability of COSMO–WRF to
represent spatial snow precipitation patterns, they are validated against
operational weather radar measurements. Estimated COSMO–WRF precipitation is
generally higher than estimated radar precipitation, most likely due to an
overestimation of orographic precipitation enhancement in the model. The high
precipitation amounts also lead to a higher spatial variability in the model
compared to radar estimates. Overall, an autocorrelation and scale analysis
of radar and COSMO–WRF precipitation patterns at a horizontal grid spacing
of 450 m show that COSMO–WRF captures the spatial variability normalized by
the domain-wide variability in precipitation patterns down to the scale of a
few kilometers. However, simulated precipitation patterns systematically show
a lower variability on the smallest scales of a few hundred meters compared to radar
estimates. A comparison of spatial variability for different model
resolutions gives evidence for an improved representation of local
precipitation processes at a horizontal resolution of 50 m compared to
450 m. Additionally, differences of precipitation between 2830 m above sea
level and the ground indicate that near-surface processes are active in the
model.</p
Polarimetric radar characteristics of lightning initiation and propagating channels
In this paper we present an analysis of a large dataset of lightning and polarimetric weather radar data collected in the course of a lightning measurement campaign that took place in the summer of 2017 in the area surrounding Säntis, in the northeastern part of Switzerland. For this campaign and for the first time in the Alps, a lightning mapping array (LMA) was deployed. The main objective of the campaign was to study the atmospheric conditions leading to lightning production with a particular focus on the lightning discharges generated due to the presence of the 124¿m tall Säntis telecommunications tower. In this paper we relate LMA very high frequency (VHF) sources data with co-located radar data in order to characterise the main features (location, timing, polarimetric signatures, etc.) of both the flash origin and its propagation path. We provide this type of analysis first for all of the data and then we separate the datasets into intra-cloud and cloud-to-ground flashes (and within this category positive and negative flashes) and also upward lightning. We show that polarimetric weather radar data can be helpful in determining regions where lightning is more likely to occur but that lightning climatology and/or knowledge of the orography and man-made structures is also relevant.Peer ReviewedPostprint (author's final draft
Teaching and learning in a multilingual Europe: findings from a cross-european study
School classrooms within the EU are multilingual learning environments. The diversity of pupils in classrooms raises significant challenges for teachers, but to date, there are no data from large-scale surveys that compare views within and across European countries. A bespoke questionnaire was designed to examine views of current classroom learning environments with respect to the multilingualism. The questionnaire was piloted and subsequently completed by 2792 teachers across different European countries. Eleven countries provided sufficient data for analyses. Results from structural equation model- ling showed that teachers’ attitudes could be reliably measured across Europe with the use of carefully devised questionnaire, whose loading and factor structure remained invariant across countries. Teachers’ views about multilingualism were most challenged by the numbers of children in their classes, not the percentage of multilingual pupils in the class. Countries differed in how they perceived multilingualism, with their differences leading to distinctive country clusters. Gender and education level (elementary vs. secondary) differences were also observed irrespective of country. These findings enhance our understanding of the role that the characteristics of teachers and their classrooms play in a multilingual setting across diverse European settings. The practical relevance of the results and new opportunities for teacher training are discussed
The occurrence of germline BRCA1 and BRCA2 sequence alterations in Slovenian population
<p>Abstract</p> <p>Background</p> <p>The <it>BRCA1 </it>and <it>BRCA2 </it>mutation spectrum and mutation detection rates according to different family histories were investigated in 521 subjects from 322 unrelated Slovenian cancer families with breast and/or ovarian cancer.</p> <p>Methods</p> <p>The <it>BRCA1 </it>and <it>BRCA2 </it>genes were screened using DGGE, PTT, HRM, MLPA and direct sequencing.</p> <p>Results</p> <p>Eighteen different mutations were found in <it>BRCA1 </it>and 13 in <it>BRCA2 </it>gene. Mutations in one or other gene were found in 96 unrelated families. The mutation detection rates were the highest in the families with at least one breast and at least one ovarian cancer - 42% for <it>BRCA1 </it>and 8% for <it>BRCA2</it>. The mutation detection rate observed in the families with at least two breast cancers with disease onset before the age of 50 years and no ovarian cancer was 23% for <it>BRCA1 </it>and 13% for <it>BRCA2</it>. The mutation detection rate in the families with at least two breast cancers and only one with the disease onset before the age of 50 years was 11% for <it>BRCA1 </it>and 8% for <it>BRCA2</it>. In the families with at least two breast cancers, all of them with disease onset over the age of 50 years, the detection rate was 5% for <it>BRCA2 </it>and 0% for <it>BRCA1</it>.</p> <p>Conclusion</p> <p>Among the mutations detected in Slovenian population, 5 mutations in <it>BRCA1 </it>and 4 mutations in <it>BRCA2 </it>have not been described in other populations until now. The most frequent mutations in our population were c.181T > G, c.1687C > T, c.5266dupC and c.844_850dupTCATTAC in <it>BRCA1 </it>gene and c.7806-2A > G, c.5291C > G and c.3978insTGCT in <it>BRCA2 </it>gene (detected in 69% of <it>BRCA1 </it>and <it>BRCA2 </it>positive families).</p
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