133 research outputs found

    Modeling the transport of Saharan dust toward the Mediterranean region: an important issue for its ecological implications

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    Airborne particulate matter (PM) is presently an environmental problem of primary concern, whose role in air quality, climatic and ecological issues is well recognized, though still a matter of extensive investigations (Intergovernmental Panel on Climate Change, 2007).It is of great scientific interest to detect sources of atmospheric particulate matter and quantify their influence on the global and local scales. Unfortunately, emissions are usually not directly available, while PM concentration time series are experimentally accessible, so that the problem often consists in "inverting" these data to determine the region of influence that caused the measured concentration. In this paper we are concerned with an alternative approach to inverse modeling based on backward trajectory analysis (BTA); this approach has the potential to overcome some limitations associated with traditional BTA.We apply this method to the analysis of PM time series from the Monte Cimone observatory, hereafter MCT, a high altitude station on the top of the Italian Northern Apennines, with the aim of estimate the contribution of Saharan dust transport on PM concentration levels registered in the Mediterranean region

    Fifty Years of PMV Model: Reliability, Implementation and Design of Software for Its Calculation

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    In most countries, PMV is the reference index for the assessment of thermal comfort conditions in mechanically conditioned environments. It is also the basis to settle input values of the operative temperature for heating and cooling load calculations, sizing of equipment, and energy calculations according to EN 16798-1 and 16798-2 Standards. Over the years, great effort has been spent to study the reliability of PMV, whereas few investigations were addressed to its calculation. To study this issue, the most significant apps devoted to its calculation have been compared with a reference software compliant with EN ISO 7730 and the well-known ASHRAE Thermal Comfort Tool. It has been revealed that only few apps consider all six variables responsible for the thermal comfort. Relative air velocity is not considered by ASHRAE Thermal Comfort Tool and, finally, the correction of basic insulation values due to body movements introduced by EN ISO 7730 and EN ISO 9920 Standards has only been considered in one case. This implies that most software and apps for the calculation of PMV index should be used with special care, especially by unexperienced users. This applies to both research and application fields

    EVOLUTIONARY ADAPTATIONS IN ANTARCTIC FISH: THE OXYGEN-TRANSPORT SYSTEM

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    Understanding molecular adaptations evolved in response to environmental temperature changes is essential, because temperature affects the kinetic energy of molecules and modifies molecular interactions, macromolecular stability/functioning and membrane features. Environmental oxygen availability may also play an important role in the evolution of polar marine organisms, as suggested by the physiological and biochemical strategies adopted by these organisms to acquire, deliver and scavenge oxygen.This review summarises the current knowledge on the structure and function of hemoglobins of fish living in Antarctic habitats. The variety of adaptations underlying the ability of Antarctic fish to survive at temperatures permanently close to freezing is unique among teleosts. The dominant perciform suborder Notothenioidei affords an excellent study group for elaborating the evolution of biochemical adaptation to temperature. The availability of notothenioid taxa living in a wide range of latitudes (Antarctic, sub-Antarctic, and temperate regions) offers a remarkable opportunity to study the physiological and biochemical characters gained and, conversely, lost in response to cold and to reconstruct the likely evolutionary events modulating the ability to carry oxygen in freezing habitats. Although oxygen can be transported in freely dissolved form most animals rely on one or more protein carriers to deliver it to the respiring tissues. Compared to temperate and tropical species, high-Antarctic notothenioids have evolved reduced hemoglobin concentration/multiplicity. The Antarctic family Channichthyidae (the notothenioid crown group) is devoid of hemoglobin. All extant icefish species lack hemoglobin and many have lost myoglobin expression. In these species, oxygen delivery to tissues occurs by transport of the gas physically dissolved in the plasma.ADAPTACIONES EVOLUTIVAS EN PECES ANTÁRTICOS: EL SISTEMA DE TRANSPORTE DE OXÍGENO. Comprender las adaptaciones moleculares que han evolucionado en respuesta a los cambios de temperatura del medio ambiente es esencial, porque la temperatura afecta la energía cinética de las moléculas y  modiica  las  interacciones  moleculares,  la  estabilidad  de  las  macromoleculares,  sus  características  y  el funcionamiento de la membrana. La disponibilidad de oxígeno ambiental desempeña un papel importante en la evolución de los organismos marinos polares, como se evidencia en las estrategias isiológicas y bioquímicas adoptadas  por  estos  organismos  para  adquirir,  gastar  y  usar  oxígeno.  Esta  revisión  resume  el  conocimiento actual sobre la estructura y función de la hemoglobina de los peces que viven en hábitats antárticos. La amplia variedad de adaptaciones que permiten que los peces antárticos tengan la capacidad para sobrevivir de forma permanente en temperaturas cerca de la congelación es única entre los teleósteos. El suborden Notothenioidei, perteneciente a los Perciformes, es un excelente grupo para el estudio de la evolución y adaptación bioquímica a la temperatura. La gran variedad de taxones de nototénidos que viven en una amplia variedad de latitudes (Antártida, sub-antárticas, y las regiones templadas) ofrece una oportunidad extraordinaria para estudiar las características  isiológicas  y  bioquímicas  adquiridas  y  perdidas  por  este  grupo  en  respuesta  al  frío,  además de la posibilidad de reconstruir  los eventos más probables que direccionaron la evolución de la capacidad de transportar oxígeno en hábitats polares. Aunque el oxígeno puede ser transportado en su forma libre disuelta, la mayoría de los animales dependen de una o más proteínas para entregarlo a los tejidos para la respiración. En comparación con especies de zonas templadas y tropicales, los nototenoideos de la alta Antártida han evolucionado reduciendo la concentración y multiplicidad de hemoglobina. La familia antártica Channichthyidae (el grupo con corona de los Nototénidos) carece de la hemoglobina. Todas las especies de peces existentes que viven en el hielo carecen de hemoglobina y muchas han perdido la expresión de la mioglobina. En estas especies, el aporte de oxígeno a los tejidos se produce por el transporte del gas físicamente disuelto en el plasma. Palabras clave: Antártida; adaptaciones al frio; evolución; hemoglobina.ADAPTAÇÕES EVOLUTIVAS EM PEIXES ANTÁTRTICOS: O SISTEMA DE TRANSPORTE DE OXIGÊNIO.  Compreender as adaptações moleculares envolvidas na resposta às mudanças na temperatura  ambiental  é  essencial,  pois  a  temperatura  afeta  a  energia  cinética  das  moléculas  e  modiica  as interações moleculares, a estabilidade/funcionamento das macromoléculas e as características da membrana. A disponibilidade de oxigênio no ambiente pode também ter um importante papel na evolução dos organismos marinhos polares, como indicado pelas estratégias isiológicas e bioquímicas adotadas por estes organismos para adquirir, transportar e trocar oxigênio.   Esta revisão resume o conhecimento atual da estrutura e funcionamento das hemoglobinas de peixes que ocorrem em ambientes Antárticos. A diversidade de adaptações que sustentam a habilidade de peixes antárticos sobreviverem em temperaturas permanentemente próximas do congelamento é  única  entre  os  teleósteos.  A  dominante  sub-ordem  Perciforme  Notothenioidei  apresenta-se  como  um excelente  grupo  de  estudo  para  melhorar  o  conhecimento  sobre  a  evolução  das  adaptações  bioquímicas  à temperatura. A ocorrência de nototenióides em uma ampla variedade de latitudes (Antártica, sub-Antártica e regiões temperadas) oferece uma oportunidade notável para estudar as características isiológicas e bioquímicas obtidas  e,  por  outro  lado,  perdidas  em  resposta  ao  frio,  além  de  tornar  possível  a  reconstrução  dos  eventos evolutivos  que  provavelmente  modularam  a  habilidade  desses  peixes  de  transportar  oxigênio  em  ambientes extremamente frios. Embora  o  oxigênio  possa  ser  transportado  livremente  na  sua  forma  dissolvida,  a  maioria  dos  animais depende de um ou mais tipos de proteínas carreadoras para entregar o oxigênio aos tecidos. Quando comparadas às  espécies  temperadas  e  tropicais,  os  nototenióides  da  região Antártica,  propriamente  dita,  desenvolveram reduzida  concentração/multiplicidade  de  hemoglobinas.  A  família  de  peixes  Antárticos  Channichthyidae (crown group  nototenióide)  não  apresenta  hemoglobina.  Todas  as  espécies  de iceish  (peixes-do-gelo)  não possuem hemoglobinas e muitas também não produzem mioglobinas. Nessas espécies, o transporte de oxigênio aos tecidos ocorre através do gás isicamente dissolvido no plasma. Palavras-chave: Antártica; adaptações ao frio; evolução; hemoglobina

    Greenhouse gas emissions from urban area of Naples

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    Urban areas are among the main causes of greenhouse gases emissions on the planet, despite covering relatively small areas of the land. Recently, a number of projects aim at monitoring the dynamics of city emissions using micro meteorological measurements by applying the technique of eddy correlation for measuring the fluxes of carbon dioxide, water, methane and energy. In this perspective, a super-site for the measurement of atmospheric pollutants from urban sources has been established in Naples (Campania, Southern Italy), where the complex layout of the coast and surrounding mountains favours the development of combined sea breeze upslope winds and the evolution of return flows with several layers of pollutants and subsidence. At the super-site, an eddy covariance tower has been installed on the rooftop of the Meteorological Observatory of Largo San Marcellino, situated in the historical city centre: a fast response ultrasonic anemometer (Gill WindMaster) has been mounted on a 10-m mast, alongside three insulated inlet lines through which the air is sampled for gaseous pollutants and particulate matter. The height of the terrace is on average 35 m above the irregular street level, resulting in an overall measuring height of 45 m. Mixing ratios of CO2, CH4 and H2O are measured by an infrared spectrometer (10 Hz, Los Gatos Research). The results shown that the mean urban levels of CO2 are between 420-520 ppm; the mean levels of CH4 span between 1.85-2.48 ppm. These fluxes are representative of varying footprint source areas, covering the historical centre of Naples, the harbour, and some main traffic arteries of the city. The analysis of these measurements on long-term will allow to establish relationships between the fluxes of greenhouse gases and the other pollutant species measured

    Local site effects estimation at Amatrice (Central Italy) through seismological methods

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    We present the results of seismological and geophysical investigations performed by the “Istituto Nazionale di Geofisica e Vulcanologia” team operating in Amatrice village (Central Italy), in the emergency phases following the Mw 6.0 event of August 24th 2016, that caused severe damage in downtown and surrounding areas. Data from seven seismic stations equipped with both weak and strong motion sensors are analyzed in terms of standard spectral ratio to empirically define amplification function using a bedrock reference site. Ambient vibration spectral ratios between horizontal and vertical component of motion are also evaluated in a large number of sites, spread out in the investigated area, to recover the resonance frequency of the soft soil outcropping layers and to generalize the results obtained by earthquake data. Ambient noise vibration are also used for applying a 2D array approach based on surface waves techniques in order to define the near-surface velocity model and to verify its lateral variation. The results allows to better understand the amplification factors in the investigated area, showing spatial variation of site effects despite of the homogeneous shallow geological condition indicated by the microzonation studies available at moment of the described field campaign. The analysis reveals a diffuse amplification effect which reaches its maximum values in downtown area with a resonant frequency of about 2 Hz. The obtained results were used to integrate the microzonation studies and they can be used for urban planning and reconstruction activities.Published5713–57394T. Sismicità dell'ItaliaJCR Journa

    Genetic variants associated with gastrointestinal symptoms in Fabry disease.

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    Gastrointestinal symptoms (GIS) are often among the earliest presenting events in Fabry disease (FD), an X-linked lysosomal disorder caused by the deficiency of α-galactosidase A. Despite recent advances in clinical and molecular characterization of FD, the pathophysiology of the GIS is still poorly understood. To shed light either on differential clinical presentation or on intervariability of GIS in FD, we genotyped 1936 genetic markers across 231 genes that encode for drug-metabolizing enzymes and drug transport proteins in 49 FD patients, using the DMET Plus platform. All nine single nucleotide polymorphisms (SNPs) mapped within four genes showed statistically significant differences in genotype frequencies between FD patients who experienced GIS and patients without GIS: ABCB11 (odd ratio (OR) = 18.07, P = 0,0019; OR = 8.21, P = 0,0083; OR=8.21, P = 0,0083; OR = 8.21, P = 0,0083),SLCO1B1 (OR = 9.23, P = 0,0065; OR = 5.08, P = 0,0289; OR = 8.21, P = 0,0083), NR1I3 (OR = 5.40, P = 0,0191) and ABCC5 (OR = 14.44, P = 0,0060). This is the first study that investigates the relationships between genetic heterogeneity in drug absorption, distribution, metabolism and excretion (ADME) related genes and GIS in FD. Our findings provide a novel genetic variant framework which warrants further investigation for precision medicine in FD

    Co-occurrence of Beckwith-Wiedemann syndrome and pseudohypoparathyroidism type 1B: coincidence or common molecular mechanism?

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    Imprinting disorders are congenital diseases caused by dysregulation of genomic imprinting, affecting growth, neurocognitive development, metabolism and cancer predisposition. Overlapping clinical features are often observed among this group of diseases. In rare cases, two fully expressed imprinting disorders may coexist in the same patient. A dozen cases of this type have been reported so far. Most of them are represented by individuals affected by Beckwith–Wiedemann spectrum (BWSp) and Transient Neonatal Diabetes Mellitus (TNDM) or BWSp and Pseudo-hypoparathyroidism type 1B (PHP1B). All these patients displayed Multilocus imprinting disturbances (MLID). Here, we report the first case of co-occurrence of BWS and PHP1B in the same individual in absence of MLID. Genome-wide methylation and SNP-array analyses demonstrated loss of methylation of the KCNQ1OT1:TSS-DMR on chromosome 11p15.5 as molecular cause of BWSp, and upd(20)pat as cause of PHP1B. The absence of MLID and the heterodisomy of chromosome 20 suggests that BWSp and PHP1B arose through distinct and independent mechanism in our patient. However, we cannot exclude that the rare combination of the epigenetic defect on chromosome 11 and the UPD on chromosome 20 may originate from a common so far undetermined predisposing molecular lesion. A better comprehension of the molecular mechanisms underlying the co-occurrence of two imprinting disorders will improve genetic counselling and estimate of familial recurrence risk of these rare cases. Furthermore, our study also supports the importance of multilocus molecular testing for revealing MLID as well as complex cases of imprinting disorders

    Site effects estimation and their effects on strong ground motion at Amatrice village (Central Italy)

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    We present a summary of seismological and geophysical investigations at Amatrice (Central Italy), a village seated on an alluvial terrace and severely stroke by the Mw 6.0 event of August 24th 2016. The high vulnerability alone could not explain the heavy damage (X-XI MCS), whereas the vicinity of the seismic source and the peculiar site effects should be claimed to understand the ground motion variability. After the first mainshock, we investigated the Amatrice terrace for microzonation purposes together with several Italian institutions (Priolo et al., Bull. Earthquake Eng. 2019). In particular: (i) we installed 7 seismic stations as a part of the 3A network (DOI: 10.13127/SD/ku7Xm12Yy9; Cara et al., Sci. Data 2019); we performed (ii) an extensive campaign of 60 single-station ambient noise measurements (downtown stations recorded also few earthquakes), and (iii) several 2D passive seismic arrays aimed at obtaining Vs profiles down to a depth of few tens of meters (Milana et al., Bull. Earthquake Eng. 2019). Earthquake recordings were used to empirically evaluate ground motion amplification effects through spectral ratio approaches, and noise data were collected for defining the spatial distribution of the resonance frequencies. Data analysis reveals a diffuse amplification effect that reaches its maximum values in downtown area with a resonant frequency (f0) of about 2 Hz. Seismic amplification is also characterized by spatial variation and directional amplification, mainly in downtown to the west side of the alluvial terrace, and related to both stratigraphic and topographic effects. This effect tends to decrease and almost vanishes in the central part of the terrace, and it increases again moving towards its eastern edge with a clear shift of f0 towards higher frequencies. Empirical transfer functions were then used to recover the ground motion that could have hit the historical center of Amatrice during the August 24th mainshock, through the convolution with the only record in the vicinity (IT.AMT station experienced a PGA of 0.87 g). The reconstructed peak values are much greater than expected from ground motion models, showing that detailed studies on local site response can largely modify the seismic hazard assessment.PublishedSan Francisco, California (USA)4T. Sismicità dell'Italia5T. Sismologia, geofisica e geologia per l'ingegneria sismic
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