Ricostruzione ad alta risoluzione delle variazioni climatiche dell'Antartide orientale durante l'Olocene

2011/2012Le carote di ghiaccio sono uno degli strumenti più utili nella ricostruzione delle variazioni climatiche del passato. In questo studio i principi della Geochimica Isotopica sono stati applicati alla carota di ghiaccio di TALDICE (159°11'E 72°49'S, quota 2315 m s.l.m., temperatura media annua superficiale -41°C, tasso di accumulo 80 mm we yr-1, lunghezza della carota 1620 m) raccolta nell’ambito del progetto internazionale TALDICE (TALos Dome ICE core project). Il lavoro scientifico sviluppato in questa tesi è stato portato a termine nell’ambito del progetto HOLOCLIP (www.holoclip.org) volto all’integrazione dei proxy climatici ottenuti dalle carote di ghiaccio e di sedimento marino dell’Antartide con i dati della modellistica (modello climatico di complessità intermedia LOVECLIM) relativi al presente interglaciale, l’Olocene. Lo scopo di questa tesi è di ricostruire, con un’alta risoluzione temporale (decennale), la variabilità climatica nel sito di Talos Dome per l’intero Olocene (circa gli ultimi 12.000 anni), attraverso l’analisi degli isotopi stabili dell’ossigeno (δ18O) sui campioni di dettaglio (10 cm) dei primi 690 metri di questa carota. Sulla base della scala dell’età messa a punto da Severi et al. (2012), ottenuta sincronizzando il segnale dei solfati vulcanici di TALDICE con quello di EDC, questo passo di campionamento corrisponde ad una risoluzione temporale media relativa all’Olocene di 1.8 anni. Il trend a lungo termine ottenuto dal profilo del δ18O di TALDICE, mostra degli andamenti in comune con quelli già osservati in altre carote di ghiaccio provenienti dal plateau dell’Antartide orientale ossia un optimum, all’inizio dell’Olocene tra circa 11.6 e 9.2 ka BP, un minimo centrato intorno agli 8 ka e un optimum secondario intorno ai 2 ka. Applicando uno smoothing binomiale a 500 anni sul record isotopico e sottraendo il trend a lungo termine sono stati identificati 12 sub-eventi caldi significativi, intervallati da altrettanti sub-eventi freddi occorsi durante l’Olocene, corrispondenti ad una variazione di temperatura di circa 0.8°C. Le fasi corrispondenti a trends di raffreddamento corrispondono ad una diminuzione della frequenza, dell’ampiezza e della durata dei sub-eventi significativi. La wavelet analysis effettuata sul profilo delle anomalie isotopiche permette di individuare due periodi, prima e dopo i 6.5-6.8 ka BP, caratterizzati da diverse frequenze predominanti. Questa transizione delle periodicità avviene subito dopo il completamento dell’apertura del Mare di Ross (Baroni and Hall, 2004; Baroni et al., 2005) ed è visibile anche dai risultati della wavelet analysis effettuata sui record delle polveri e sul record isotopico della carota di ghiaccio di Taylor Dome. L’analisi della variabilità (deviazione standard mobile di 3000 anni) applicata su TALDICE, Taylor Dome, EDC e EDML mostra una somiglianza della distribuzione della variabilità climatica nei siti più costieri rispetto quelli più interni (EDC), probabilmente associabile a processi legati alla variazione del ghiaccio marino. Dall’osservazione dei principali trend di temperatura ricavati sia dalle carote di ghiaccio antartiche che da carote di sedimento marino dell’emisfero meridionale per i periodi 10-8, 4-6, 6-4, 4-1 ka BP si evidenzia un generale trend di raffreddamento alle alte latitudini dell’emisfero meridionale durante l’Olocene. Nelle carote di ghiaccio antartiche questo trend di raffreddamento non è presente in maniera omogenea in tutti i record isotopici: in alcuni casi si verifica una situazione di relativa stabilità (EDC), in altri un trend di leggero riscaldamento (TALDICE) e in altri ancora un trend di raffreddamento (Vostok). Dal record composito riferito agli ultimi 2000 anni, prodotto per l’Antartide Orientale nell’ambito di questo lavoro di tesi, risulta che nel periodo che va dal 400 al 900 CE (Common Era) c’è una prevalenza di anomalie positive (calde) mentre nel periodo successivo, che va dal 1300 CE al 1800 CE, c’è una prevalenza di anomalie negative (fredde), superiori in numero, durata ed intensità rispetto alle prime. Nel corso degli ultimi 2000 anni si osserva un debole trend di raffreddamento di -0.1‰/1ka ossia di -0.2°C/1ka in accordo con i risultati del recente lavoro pubblicato nell’ambito del programma PAGES 2k che evidenzia un trend di diminuzione della temperature a scala globale nel corso degli ultimi 2000 anni fino al periodo pre-industriale.XXV Ciclo197

Reconstructing Antarctic Holocene climate/environmental changes from ice and marine cores

Paleotemperature reconstructions from Antarctic ice cores rely mainly on δD and δ18O records, with the main key factors controlling their observed distribution in Antarctic surface snow being related to the condensation temperature of the precipitation and the origin of the moisture. Reconstructions of past sea-surface temperatures (SST) and sea ice cover (SIC) from marine cores at high southern latitudes mainly rely on diatom-based transfer functions. However, quantitative records of SST and SIC are concentrated in the mid-latitudes of the Southern Ocean and only few records exist in the Antarctic coastal areas. Here we present an overview of the Holocene climate records that have been compiled in the framework of the ESF-HOLOCLIP project, as well as a new isotopic record from the TALDICE ice core, recently drilled in a peripheral dome facing the Ross Sea. One of the main goals of HOLOCLIP is to reconstruct Holocene climate/environmental changes from ice and marine cores and integrate these data in model simulations. The main common features recognized in Holocene climate records obtained from ice cores are a warm early Holocene (from about 10 to 11.5 ka BP), a cool period centred at ~8 ka BP and a secondary optimum peaking at ~4 ka BP. The Holocene climate reconstructions obtained from sediment cores demonstrate a warmer early-mid Holocene hypsithermal followed by a cooler neoglacial with an amplitude and timing of the transitions variable regionally around Antarctica. Though there exist some problems in both ice and marine core records (chronologies, temporal resolution, global vs. regional, annual vs. seasonal), such approach is unique to fuel paleoclimate models and to better understand the ocean-ice-atmosphere interactions at high southern latitudes beyond the instrumental period

VI Jornadas Estudiantiles de Escritura e Investigación “Cuando escribir es investigar”

Actas correspondientes a VI Jornadas Estudiantiles de Escritura e Investigación “Cuando escribir es investigar”Fil: Apellido, Nombre. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Letras; Argentina.Fil: Arzuaga, Gonzalo. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Bassols, Rius Glória. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Benítez Braida, Cintia. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Bohnhoff, Leandro. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Cabral, Rocío. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Chia, Julián Ignacio. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Converti, Lucía Antonella. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: D' Angelo, Evelin. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Desuque, Lucía. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Gelmini, Laura Luciana. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Martínez, Aldana Lucía. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Morganti Hernández, Delfina. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Pizzuto Grossi, Antonella. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Raggio, Rocío del Cielo. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Ríos, Cecilia. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Salarí, Martina. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina.Fil: Spezzapria, Lara. Universidad Nacional de Rosario. Rosario; Santa Fe; Argentina

Best practice guidelines and recommendations on the molecular diagnosis of myotonic dystrophy types 1 and 2

Contains fulltext : 110379.pdf (publisher's version ) (Open Access)Myotonic dystrophy is an autosomal dominant, multisystem disorder that is characterized by myotonic myopathy. The symptoms and severity of myotonic dystrophy type l (DM1) ranges from severe and congenital forms, which frequently result in death because of respiratory deficiency, through to late-onset baldness and cataract. In adult patients, cardiac conduction abnormalities may occur and cause a shorter life span. In subsequent generations, the symptoms in DM1 may present at an earlier age and have a more severe course (anticipation). In myotonic dystrophy type 2 (DM2), no anticipation is described, but cardiac conduction abnormalities as in DM1 are observed and patients with DM2 additionally have muscle pain and stiffness. Both DM1 and DM2 are caused by unstable DNA repeats in untranslated regions of different genes: A (CTG)n repeat in the 3'-UTR of the DMPK gene and a (CCTG)n repeat in intron 1 of the CNBP (formerly ZNF9) gene, respectively. The length of the (CTG)n repeat expansion in DM1 correlates with disease severity and age of onset. Nevertheless, these repeat sizes have limited predictive values on individual bases. Because of the disease characteristics in DM1 and DM2, appropriate molecular testing and reporting is very important for the optimal counseling in myotonic dystrophy. Here, we describe best practice guidelines for clinical molecular genetic analysis and reporting in DM1 and DM2, including presymptomatic and prenatal testing

Underreporting of congenital rubella in Italy, 2010–2014

In accordance with the goals of the World Health Organization Regional Committee for Europe, the Italian national Measles and Rubella Elimination Plan 2010–2015 aimed to reduce the incidence of congenital rubella cases to <1 case/100,000 live births by 2015. In Italy, a passive national surveillance system for congenital rubella and rubella in pregnancy is active since 2005. We estimated the degree of underreporting of congenital rubella, performing a capture-recapture analysis of cases detected through two independent sources: the national surveillance system and the national hospital discharge database, in the years 2010–2014. We found that 6 out of 11 cases tracked in the retrospective case-finding from hospital registries had not been notified to the surveillance system, and we estimated a degree of underreporting of 53% for the period 2010–2014. This approach showed to be simple to perform, repeatable, and effective.Conclusion: In order to reduce underreporting, some actions aimed at strengthening surveillance procedures are needed. The adoption on a routine basis of the review of hospital discharge registries for case-finding, monthly zero-reporting, and actions to train and sensitize all the specialists involved in the care of pregnant women and the newborns to notification procedures are recommended.What is Known• In Italy, the incidence of congenital rubella was below the WHO target of 1/100,000 live births in 2005–2015, except for two peaks in 2008 and 2012 (5 and 4/100,000, respectively).• Further efforts are required to improve congenital rubella surveillance so that it is more sensitive and specific. The WHO proposes retrospective case-finding from hospital records as an alternative approach to detect infants with congenital rubella.Whatis New• Underreporting of congenital rubella in Italy was 53% in 2010–2014.• Hospital discharge registries resulted to be an appropriate source to detect congenital rubella cases

Continental-scale temperature variability during the past two millennia

Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years

Continental-Scale Temperature Variability during the Past Two Millennia: Supplementary Information

Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years