48 research outputs found

    Tornadoes and waterspouts in Catalonia (1950–2009)

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    This paper presents a preliminary climatology of tornadoes and waterspouts in Catalonia (NE Iberian Peninsula). A database spanning 60 yr (1950–2009) has been developed on the basis of information collected from various sources such as weather reports, insurance companies, newspapers and damage surveys. This database has been subjected to a rigorous validation process, and the climatology describes its main features: timing, spatial pattern, and trends in the tornado and waterspout distribution. Results show the highest concentration of tornadoes from August to October, the highest density in the heavily populated coastal areas and a growing positive trend that is likely more closely linked to an increase in observation and perception rather than a real climatic trend

    An observational study of the 7 September 2005 Barcelona tornado outbreak

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    This paper presents an observational study of the tornado outbreak that took place on the 7 September 2005 in the Llobregat delta river, affecting a densely populated and urbanised area and the Barcelona International airport (NE Spain). The site survey confirmed at least five short-lived tornadoes. Four of them were weak (F0, F1) and the other one was significant (F2 on the Fujita scale). They started mostly as waterspouts and moved later inland causing extensive damage estimated in 9 million Euros, three injured people but fortunately no fatalities. Large scale forcing was provided by upper level diffluence and low level warm air advection. Satellite and weather radar images revealed the development of the cells that spawned the waterspouts along a mesoscale convergence line in a highly sheared and relatively low buoyant environment. Further analysis indicated characteristics that could be attributed indistinctively to non-supercell or to mini-supercell thunderstorms

    The genes of freedom: Genome-wide insights into marronage, admixture and ethnogenesis in the Gulf of Guinea

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    The forced migration of millions of Africans during the Atlantic Slave Trade led to the emergence of new genetic and linguistic identities, thereby providing a unique opportunity to study the mechanisms giving rise to human biological and cultural variation. Here we focus on the archipelago of São Tomé and Príncipe in the Gulf of Guinea, which hosted one of the earliest plantation societies relying exclusively on slave labor. We analyze the genetic variation in 25 individuals from three communities who speak distinct creole languages (Forros, Principenses and Angolares), using genomic data from expanded exomes in combination with a contextual dataset from Europe and Africa, including newly generated data from 28 Bantu speakers from Angola. Our findings show that while all islanders display mixed contributions from the Gulf of Guinea and Angola, the Angolares are characterized by extreme genetic differentiation and inbreeding, consistent with an admixed maroon isolate. In line with a more prominent Bantu contribution to their creole language, we additionally found that a previously reported high-frequency Y-chromosome haplotype in the Angolares has a likely Angolan origin, suggesting that their genetic, linguistic and social characteristics were influenced by a small group of dominant men who achieved disproportionate reproductive success.1. Introduction 2. Materials and Methods 2.1. Population Samples 2.2. Expanded Exome Sequencing, Variant Calling and Quality Control 2.3. Population Structure Analyses 2.4. Genetic Diversity 2.5. Mitochondrial DNA and Y-Chromosome Variation 3. Results 3.1. Genetic Structure 3.2. Genetic Diversity 3.3. Reanalyzing previously generated uniparental Data 4. Discussio

    An observational study of the 7 September 2005 Barcelona tornado outbreak

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    This paper presents an observational study of the tornado outbreak that took place on the 7 September 2005 in the Llobregat delta river, affecting a densely populated and urbanised area and the Barcelona International airport (NE Spain). The site survey confirmed at least five short-lived tornadoes. Four of them were weak (F0, F1) and the other one was significant (F2 on the Fujita scale). They started mostly as waterspouts and moved later inland causing extensive damage estimated in 9 million Euros, three injured people but fortunately no fatalities. Large scale forcing was provided by upper level diffluence and low level warm air advection. Satellite and weather radar images revealed the development of the cells that spawned the waterspouts along a mesoscale convergence line in a highly sheared and relatively low buoyant environment. Further analysis indicated characteristics that could be attributed indistinctively to non-supercell or to mini-supercell thunderstorms

    Characterization of the Oral Microbiome of Medicated Type-2 Diabetes Patients

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    Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease that is becoming a significant global health care problem. Several studies have shown that people with diabetes are more susceptible to oral problems, such as periodontitis and, although the causes are still inconclusive, oral microbiota is considered to play a major role in oral health. This study aimed to characterize the oral microbiome of a sample representing T2DM patients from Portugal and exploit potential associations between some microorganisms and variables like teeth brushing, smoking habits, average blood sugar levels, medication and nutrient intake. By sequencing the hypervariable regions V3-V4 of the 16S rRNA gene in 50 individuals belonging to a group of diabetes patients and a control group, we found a total of 232 taxa, from which only 65% were shared between both groups. No differences were found in terms of alpha and beta diversity between categories. We did not find significant differences in the oral microbiome profiles of control and diabetes patients. Only the class Synergistia and the genus TG5, which are related to periodontitis, were statistically more frequent in the control group. The similar microbiome profiles of medicated diabetics and the control group indicates that the relationship between the T2DM and the oral microbiome might be more related to either the lifestyle/diet rather than diabetes per se. Moreover, this study provides, for the first time, insights into the oral microbiome of a population with a high prevalence of diabetes.This work was supported by the European Union’s Horizon 2020 Research and Innovation Programme under the Grant Agreement Number 857251. LP-P was funded by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P. MG-V was funded through UID/BIA/50027/2019 from FCT

    Functional impact and evolution of a novel human polymorphic inversion that disrupts a gene and creates a fusion transcript

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    Since the discovery of chromosomal inversions almost 100 years ago, how they are maintained in natural populations has been a highly debated issue. One of the hypotheses is that inversion breakpoints could affect genes and modify gene expression levels, although evidence of this came only from laboratory mutants. In humans, a few inversions have been shown to associate with expression differences, but in all cases the molecular causes have remained elusive. Here, we have carried out a complete characterization of a new human polymorphic inversion and determined that it is specific to East Asian populations. In addition, we demonstrate that it disrupts the ZNF257 gene and, through the translocation of the first exon and regulatory sequences, creates a previously nonexistent fusion transcript, which together are associated to expression changes in several other genes. Finally, we investigate the potential evolutionary and phenotypic consequences of the inversion, and suggest that it is probably deleterious. This is therefore the first example of a natural polymorphic inversion that has position effects and creates a new chimeric gene, contributing to answer an old question in evolutionary biology

    Tornadoes over complex terrain: An analysis of the 28th August 1999 tornadic event in eastern Spain

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    On 28 August 1999, a tornadic storm developed during the afternoon over the Gudar range, near the border between Teruel and Castello ́n provinces (Sistema Ibérico, eastern Spain). The area has a characteristic complex terrain with peaks up to 2000 m. At least one tornado developed, which attained F3 intensity, producing severe damage in the forest that covers the mountains. The region is well known as a summer convective storm nest and, not surprisingly, a range in the Sistema Iberico is called Sierra del Rayo (lightning range). The meteorological situation on 28 August 1999 shows the presence of a thermal low over the Iberian peninsula, producing warm and moist air advection towards inland Castellon at low levels. Meanwhile, a cold trough crossed the Iberian Peninsula from west to east at upper levels. Deep convection is identified on the Meteosat images during the afternoon, when the upper level trough reached the area where warm and humid Mediterranean air was concentrated. The radar images reveal signals indicating the supercellular character of the tornado-producing storm. Weak echo region, frontal and rear inflow notches are identified on the low-level CAPPIs images. In order to study the roles of the orography and the solar radiation on the ingredients associated with the tornadic storm development, numerical simulations of the event were performed, using the non- hydrostatic MM5 model. Very fine grid resolution, up to 2 km in the horizontal, allows us to determine the role of the complex terrain in favoring environmental conditions associated with the onset of severe convection. In fact, interaction of certain low-level flows with particular topographic features with scales of about 20 to 50 km is found to generate intense small-scale circulations over the storm nesting region. A more detailed analysis of the orographic effect shows that fine scale terrain features (2-5 km) are responsible for the intensification of the convective storms, whereas modification of the low-level flow by the large-scale features (20-50 km) is able to trigger the convective systems. The effect of the solar-induced surface heating is also analyzed and it turns to be crucial not only by intensifying the Iberian thermal low and the easterly warm and moist air advection towards the area but also by promoting mountain breezes. © 2003 Elsevier B.V. All rights reserved.Peer Reviewe

    Preliminary results of the Social Impact Research Group of MEDEX: the request database (2000-2002) of two Meteorological Services

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    One of the aims of the MEDEX project is to improve the knowledge of high-impact weather events in the Mediterranean. According to the guidelines of this project, a pilot study was carried out in two regions of Spain (the Balearic Islands and Catalonia) by the Social Impact Research group of MEDEX. The main goal is to suggest some general and suitable criteria about how to analyse requests received in Meteorological Services arising out of the damage caused by weather events. Thus, all the requests received between 2000 and 2002 at the Servei Meteorològic de Catalunya as well as at the Division of AEMET in the Balearic Islands were analysed. Firstly, the proposed criteria in order to build the database are defined and discussed. Secondly, the temporal distribution of the requests for damage claims is analysed. On average, almost half of them were received during the first month after the event happened. During the first six months, the percentage increases by 90%. Thirdly, various factors are taken into account to determine the impact of specific events on society. It is remarkable that the greatest number of requests is for those episodes with simultaneous heavy rain and strong wind, and finally, those that are linked to high population density
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