Tree-ring–based summer mean temperature variations in the Adamello–Presanella Group (Italian Central Alps), 1610–2008 AD

Abstract. Climate records from remote mountain sites and for century-long periods are usually lacking for most continents and also for the European Alps. However, detailed reconstructions of climate parameters for pre-instrumental periods in mountain areas, suffering of glacial retreat caused by recent global warming, are needed in the view of a better comprehension of the environmental dynamics. We present here the first annually-resolved reconstruction of summer (JJA) mean temperature for the Adamello–Presanella Group (Central European Alps), one of the most glaciated mountain groups of the Italian Central Alps. The reconstruction has been based on four larch tree-ring width chronologies derived from living trees sampled in four valleys surrounding the Group. The reconstruction spans from 1610 to 2008 and the statistical verification of the reconstruction demonstrates the positive skill of the tree-ring dataset in tracking summer temperature variability also in the recent period

Dendroclimatic relevance of “Bosco Antico”, the most ancient living European larch wood in the southern Rhaetian Alps (Italy).

The ongoing increase in the global mean temperature at an unprecedented recorded rate is well documented. Nevertheless, knowledge of past climate variations is fundamental for a better understanding of ongoing climate change. This need is crucial in high mountain areas, where the effects of global warming are amplified and induce an accelerated glacial retreat. Thus, the use of climatic proxies such as tree-ring width offers tools to better understand the environmental dynamics in remote, sensitive sites. Here, we present the “Bosco Antico” site chronology, a six-century long dataset from the most ancient living stand in the Val di Sole area (southern Rhaetian Alps, Italy), and its relationship with summer mean temperatures. The analyses were performed on earlywood and latewood separately, as well as on tree-ring widths using static and moving correlations. The results showed that tree-rings and earlywood width are linked with June temperatures, whereas latewood width is mainly driven by July temperatures. All the analysed series were greatly influenced by June to July and June to August temperatures. Finally, a mean summer latewood-based temperature reconstruction since 1525 is proposed. It highlighted that during the last six hundred years, the summer temperatures span between -2.3 to +1.9 °C compared to the 1960–90 mean temperature (between 6.2 and 10.4 °C at the stand elevation). The coolest phase is recorded in the 1810s-20s underlining the strongest pulse of the Little Ice Age; other phases of negative anomalies are recorded in the first half of the 17th century, around 1700, and 1900 and during the 1970s. Our results add an important dataset for a specific climatic area, providing new information that will contribute to a better understanding of the climate dynamics for the study site as well as on a larger scale

Self-reported price of cigarettes, consumption and compensatory behaviours in a cohort of Mexican smokers before and after a cigarette tax increase

This paper presents a novel SAT-based approach for the computation of extensions in abstract argumentation, with focus on preferred semantics, and an empirical evaluation of its performances. The approach is based on the idea of reducing the problem of computing complete extensions to a SAT problem and then using a depth-first search method to derive preferred extensions. The proposed approach has been tested using two distinct SAT solvers and compared with three state-of-the-art systems for preferred extension computation. It turns out that the proposed approach delivers significantly better performances in the large majority of the considered cases

GLIMS-IT: contributo italiano al progetto GLIMS di monitoraggio satellitare dei ghiacciai del globo

Si illustra lo stato di avanzamento del contributo italiano al progetto GLIMS-Global Land Ice Measurements from Space che consiste nella redazione di un Atlante satellitare dei ghiacciai italiani. Dall'analisi di cinque immagini rilevate dal sensore ASTER installato sul satellite TERRA sono stati delineati i limiti dei ghiacciai nei gruppi montuosi delle Alpi Lepontine, Pusteresi, delle Dolomiti venete, del versante trentino del Cevedale e dell'Adamello-Presanella. Dal punto di vista metodologico si sono sfruttate, tra l'altro, le informazioni desumibili dai canali spettrali dell'infrarosso termico per il riconoscimento di alcuni ghiacciai coperti da detrito e, una volta delineata l'estensione del ghiacciaio, i parametri geomorfologici vengono estratti in modo automatico con un codice di calcolo che implementa i requisiti del progetto GLIMS. I risultati delle elaborazioni sono stati trasmessi al data base gestito dal National Snow and Ice Data Center ed al Comitato Glaciologico Italiano, che collabora all'iniziativa per l'aggiornamento del catasto dei ghiacciai italiani. Le informazioni per i gruppi montuosi del Cevedale e dell'Adamello-Presanella sono state organizzate in un sistema informativo territoriale in formato KML. Mediamente, nelle aree sinora investigate, è stata rilevata una diminuzione dell'estensione dei ghiacciai, dagli anni '80 al 2007, compresa tra il 34% ed il 50%, una marcata frammentazione di diversi ghiacciai e la scomparsa di alcune unità glaciologiche, confermando l'accelerazione del ritiro iniziato al termine della Piccola Età Glaciale. Si presentano i risultati dell'elaborazione di un'immagine del gruppo dell'Adamello-Presanella la cui estensione dei ghiacciai si è ridotta del 36% dagli anni '80 al 2007

Effect of inter-well interactions on non-linear beam splitters for matter-wave interferometers

We study the non-linear beam splitter in matter-wave interferometers using ultracold quantum gases in a double-well configuration in presence of non-local interactions inducing inter-well density-density coupling, as they can be realized, e.g., with dipolar gases. We explore this effect after considering different input states, in the form of either coherent, or Twin-Fock, or NOON states. We first review the non-interacting limit and the case in which only the local interaction is present, including the study of sensitivity near the self-trapping threshold. Then, we consider the two-mode model in the presence of inter-well interactions and consider the scaling of the sensitivity as a function of the non-local coupling strength. Our analysis clearly shows that non-local interactions can compensate the degradation of the sensitivity induced by local interactions, so that they may be used to restore optimal sensitivity

Local chiral interactions and magnetic structure of few-nucleon systems

The magnetic form factors of $^2$H, $^3$H, and $^3$He, deuteron photodisintegration cross sections at low energies, and deuteron threshold electrodisintegration cross sections at backward angles in a wide range of momentum transfers, are calculated with the chiral two-nucleon (and three-nucleon) interactions including $\Delta$ intermediate states that have recently been constructed in configuration space. The $A\,$=$\,$3 wave functions are obtained from hyperspherical-harmonics solutions of the Schr\"odinger equation. The electromagnetic current includes one- and two-body terms, the latter induced by one- and two-pion exchange (OPE and TPE, respectively) mechanisms and contact interactions. The contributions associated with $\Delta$ intermediate states are only retained at the OPE level, and are neglected in TPE loop (tree-level) corrections to two-body (three-body) current operators. Expressions for these currents are derived and regularized in configuration space for consistency with the interactions. The low-energy constants that enter the contact few-nucleon systems. The predicted form factors and deuteron electrodisintegration cross section are in excellent agreement with experiment for momentum transfers up to 2--3 fm$^{-1}$. However, the experimental values for the deuteron photodisintegration cross section are consistently underestimated by theory, unless use is made of the Siegert form of the electric dipole transition operator. A complete analysis of the results is provided, including the clarification of the origin of the aforementioned discrepancy.Comment: 24 pages, 13 figure

Colony size predicts division of labour in Attine ants

Division of labour is central to the ecological success of eusocial insects, yet the evolutionary factors driving increases in complexity in division of labour are little known. The size–complexity hypothesis proposes that, as larger colonies evolve, both non-reproductive and reproductive division of labour become more complex as workers and queens act to maximize inclusive fitness. Using a statistically robust phylogenetic comparative analysis of social and environmental traits of species within the ant tribe Attini, we show that colony size is positively related to both non-reproductive (worker size variation) and reproductive (queen–worker dimorphism) division of labour. The results also suggested that colony size acts on non-reproductive and reproductive division of labour in different ways. Environmental factors, including measures of variation in temperature and precipitation, had no significant effects on any division of labour measure or colony size. Overall, these results support the size–complexity hypothesis for the evolution of social complexity and division of labour in eusocial insects. Determining the evolutionary drivers of colony size may help contribute to our understanding of the evolution of social complexity

sensing characteristics of hematite and barium oxide doped hematite films towards ozone and nitrogen dioxide

Abstract Hematite (α-Fe2O3) and barium oxide doped hematite (BaO-Fe 2 O 3 ) thin films were investigated as ozone (O 3 ) and nitrogen dioxide (NO 2 ) sensing materials. Fe 2 O 3 and BaO-Fe 2 O 3 films were deposited by radio- frequency sputtering using pure Fe 2 O 3 , and 1-2% BaO doped Fe 2 O 3 targets. The 700 °C (1 hour) annealed films showed significant responses to O 3 at temperatures ranging from 150 °C to 300 °C. Although, hematite is an n-type semiconductor, the Fe 2 O 3 and BaO-Fe 2 O 3 films exhibit p-type behavior to O 3 and n- type behavior to NO 2 at the studied concentration ranges in this work. The response to oxidizing gases is not strictly an increase in resistance due to a conversion from n-type to p-type depending on gas concentrations. This effect is more visible with increasing Ba concentration