225 research outputs found
Detection and thermal description of medicanes from numerical simulation
Tropical-like cyclones rarely affect the Mediterranean region but they can
produce strong winds and heavy precipitations. These warm-core cyclones,
called MEDICANES (MEDIterranean hurriCANES), are small in size, develop over
the sea and are infrequent. For these reasons, the detection and forecast of
medicanes are a difficult task and many efforts have been devoted to identify
them.
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The goals of this work are to contribute to a proper description of these
structures and to develop some criteria to identify medicanes from numerical
weather prediction (NWP) model outputs. To do that, existing methodologies
for detecting, characterizating and tracking cyclones have been adapted to
small-scale intense cyclonic perturbations. First, a mesocyclone detection
and tracking algorithm has been modified to select intense cyclones. Next,
the parameters that define the Hart's cyclone phase diagram are tuned and
calculated to examine their thermal structure.
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Four well-known medicane events have been described from numerical simulation
outputs of the European Centre for
Medium-Range Weather Forecast (ECMWF) model. The predicted cyclones and their evolution have
been validated against available observational data and numerical analyses
from the literature
Mitochondrial DNA: a tool for populational genetics studies
Mitochondria are cellular organelles that have the function of the oxidative phosphorilation and the formation of ATP. In humans, the mtDNA is a double-stranded, circular, covalent closed molecule of 16.5 kb. The mtDNA is inherited as a haploid from the mother and heteroplasmy has been found rarely. From a populational perspective, it could be considered as a system of small, sexually isolated demes, or clonal lineages, with an evolutionary rate 5 to 10 times faster than the nuclear genome. All these characteristics make this molecule ideal for evolutionary studies. We present two applications of this molecule in genetical studies. One of these is referred to the Balearic Islands populations, Majorca, Minorca, Ibiza, and Chuetas. The other example is the populational dynamics of the different mitochondrial haplotypes in Drosophila subobscura. We also discuss the importance of nuclear markers to complete these studies as well as the study of the Y chromosome to compensate the bias produced by the study of only the mtDNA
Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
In seed plants, the colocalization of the 5S loci within the intergenic spacer (IGS) of the nuclear 45S tandem units is restricted to the phylogenetically derived Asteraceae family. However, fluorescent in situ hybridization (FISH) colocalization of both multigene families has also been observed in other unrelated seed plant lineages. Previous work has identified colocalization of 45S and 5S loci in Ginkgo biloba using FISH, but these observations have not been confirmed recently by sequencing a 1.8 kb IGS. In this work, we report the presence of the 45S–5S linkage in G. biloba, suggesting that in seed plants the molecular events leading to the restructuring of the ribosomal loci are much older than estimated previously. We obtained a 6.0 kb IGS fragment showing structural features of functional sequences, and a single copy of the 5S gene was inserted in the same direction of transcription as the ribosomal RNA genes. We also obtained a 1.8 kb IGS that was a truncate variant of the 6.0 kb IGS lacking the 5S gene. Several lines of evidence strongly suggest that the 1.8 kb variants are pseudogenes that are present exclusively on the satellite chromosomes bearing the 45S–5S genes. The presence of ribosomal IGS pseudogenes best reconciles contradictory results concerning the presence or absence of the 45S–5S linkage in Ginkgo. Our finding that both ribosomal gene families have been unified to a single 45S–5S unit in Ginkgo indicates that an accurate reassessment of the organization of rDNA genes in basal seed plants is necessary
A study on the forecast quality of the mediterranean cyclones
Comunicación presentada en: 4th Plinius Conference on Mediterranean Storms celebrada del 2 al 4 de octubre de 2002 en Palma de Mallorca.The main general objective of MEDEX is stated to be the improvement of knowledge and forecasting of cyclones that
produce high impact weather in the Mediterranean area. So, for this scope one of the intermediate goals of the project
concerns the development of an objective method to evaluate the quality of the forecast of the cyclones. The topic of the
present study is to investigate the cyclone's forecast errors in that area and to propose an objective methodology to
quantify them. An investigation on the performance of the HIRLAM(INM)-0.5 model in the forecast of cyclonic centres
has been done. Databases of analysed and forecasted cyclones for the Western Mediterranean have been used in this
study. The "distance" between the analysed and forecasted cyclone has been measured calculating the differences in the
value of the parameters chosen to describe them at the sea level surface. Results on the characteristics of the errors are
shown. An index constructed by means of these differences has been introduced to evaluate the ability of the model
forecasting cyclones, and to quantify it. From this index, two others indexes have been derived in order to discriminate
if the forecast has overestimated or underestimated some magnitudes in the description of the cyclone. Three different
time forecast ranges, H+12,H+24 and H+48, have been considered to investigate temporal trend in their quality.
Finally, to check this methodology, it has been applied to some MEDEX cases
Middle eastern genetic legacy in the paternal and maternal gene pools of Chuetas
Chuetas are a group of descendants of Majorcan Crypto-Jews (Balearic Islands, Spain) who were socially stigmatized and segregated by their Majorcan neighbours until recently; generating a community that, although after the seventeenth century no longer contained Judaic religious elements, maintained strong group cohesion, Jewishness consciousness, and endogamy. Collective memory fixed 15 surnames as a most important defining element of Chueta families. Previous studies demonstrated Chuetas were a differentiated population, with a considerable proportion of their original genetic make-up. Genetic data of Y-chromosome polymorphism and mtDNA control region showed, in Chuetas’ paternal lineages, high prevalence of haplogroups J2-M172 (33%) and J1-M267 (18%). In maternal lineages, the Chuetas hallmark is the presence of a new sub-branching of the rare haplogroup R0a2m as their modal haplogroup (21%). Genetic diversity in both Y-chromosome and mtDNA indicates the Chueta community has managed to avoid the expected heterogeneity decrease in their gene pool after centuries of isolation and inbreeding. Moreover, the composition of their uniparentally transmitted lineages demonstrates a remarkable signature of Middle Eastern ancestry—despite some degree of host admixture—confirming Chuetas have retained over the centuries a considerable degree of ancestral genetic signature along with the cultural memory of their Jewish origin.This work was partially supported by grant AAEE246/2014 from the Direcció General de R + D + I (Comu-nitat Autònoma de les Illes Balears) and European Regional Development Fund (ERDF) and FCT, Portuguese Foundation for Science and Tecnology PTDC/ATP-DEM/4545/2012 project financed by European Social Funds (COMPETE-FEDER). We are grateful to Maria Trinidad Garcia (from the Serveis Cientificotècnics of the Uni-versitat de les Illes Balears) for her assistance and help with capillary electrophoresis procedures, María Luz Gómez-Barbeito for her help in mtDNA sequencing and Meryl Wyn Jones for the English language corrections. We would also like to sincerely thank all the people who volunteered to participate in this study
Convection-induced severe winds over Menorca Island 28th October 2018. Under the watch of a forecaster
Póster presentado en: 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019
Genetic Variation in the Population of Ibiza (Spain): Genetic Structure, Geography, and Language
This is the published version, also available here: http://www.jstor.org/stable/41465529
High H2S concentration abatement in a biotrickling filter: start-up at controlled pH and effect of the EBRT on O2/H2S supply ratio
In this study, a biotrickling filter reactor was set up and used to treat high concentrations of gaseousH2S. Inoculation was carried out at an inlet H2S concentration of 1,000 ppmv (27.8 g H2S m-3 h-1)and sludge from a municipal wastewater treatment plant (MWWTP) was used as inoculum. After 3days, removal efficiency (RE) above 98 % was achieved even after the loading rate (LR) wasincreased up to 55.6 g H2S m-3 h-1 (2,000 ppmv). Operation at such LR, with an empty bed residencetime (EBRT) of 180 s and controlled pH of 6.5-7 was carried out during 3 months. The start-upphase, the effect of decreasing EBRTs at constant inlet concentration and the composition of theprocess end-products in relation to the supplied O2/H2S ratio were studied. Also, a carbon massbalance under steady state conditions was calculated.Peer ReviewedPostprint (published version
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