A new interpretation of the period-luminosity sequences of long-period variables

Period-luminosity (PL) sequences of long period variables (LPVs) are commonly interpreted as different pulsation modes, but there is disagreement on the modal assignment. Here, we re-examine the observed PL sequences in the Large Magellanic Cloud, including the sequence of long secondary periods (LSPs), and their associated pulsation modes. Firstly, we theoretically model the sequences using linear, radial, non-adiabatic pulsation models and a population synthesis model of the LMC red giants. Then, we use a semi-empirical approach to assign modes to the pulsation sequences by exploiting observed multi-mode pulsators. As a result of the combined approaches, we consistently find that sequences B and C$^{\prime}$ both correspond to first overtone pulsation, although there are some fundamental mode pulsators at low luminosities on both sequences. The masses of these fundamental mode pulsators are larger at a given luminosity than the mass of the first overtone pulsators. These two sequences B and C$^{\prime}$ are separated by a small period interval in which large amplitude pulsation in a long secondary period (sequence D variability) occurs, meaning that the first overtone pulsation is not seen as the primary mode of pulsation. Observationally, this leads to the splitting of the first overtone pulsation sequence into the two observed sequences B and C$^{\prime}$. Our two independent examinations also show that sequences A$^{\prime}$, A and C correspond to third overtone, second overtone and fundamental mode pulsation, respectively.Comment: 10 pages, 7 figures, accepted for publication in Ap

Sulla trattazione del capitale negli economisti marginalisti: il capitale come grandezza singola in alcuni scritti dei primi anni trenta

The aim of this paper is to call attention on some writings of the early 1930s by D.H. Robertson and J.R. Hicks. These writings present, with a clarity not easily found elsewhere, the two reasons why marginalist economist, who till the last three decades normally treated capital as a single magnitude, were in fact compelled to do so: the fact that only this treatment could lend plausibility to the notion of substitutability between factors of production; and the fact that a different treatment would have made it impossible to include capital among the data of the theory and at the same time to determine a “normal position” of the economic system. As is well known, the notion of capital as a single magnitude has been shown to be untenable during the controversies on capital theory of the 1960s and has consequently been abandoned by orthodox theory. But the implications of this shift in pure theory have not been widely appreciated and it is hoped that looking at the question from an historical point of view might bring some help in clarifying it.Neoclassical, Capital, Robertson, Hicks

Concorrenza e strategie anticompetitive nei settori del trasporto aereo e dei servizi aeroportuali

Le liberalizzazioni ormai compiute anche nei settori che si caratterizzano per la presenza di un’infrastruttura essenziale hanno aperto le imprese ad una varietà di comportamenti strategici che in alcuni casi possono assumere una valenza anticompetitiva. Il presente contributo si interroga sulla presenza di tali comportamenti nel mercato italiano e, concretamente, analizza quelle strategie che l’Autorità Antitrust (AGCM) ha individuato, dalla sua istituzione al maggio 2014, come anti-competitive nel settore del trasporto aereo e dei servizi aeroportuali. La lettura trasversale ragionata di tutti i procedimenti ha permesso di evidenziare l’andamento temporale delle strategie dell’incumbent, le dinamiche con cui quest’ultimo ha sfruttato la propria posizione dominante e le correlazioni ed interazioni tra i diversi comportamenti strategici posti in essere. Lo studio ha permesso di osservare una sequenzialità nelle strategie dell’incumbent, confermando l’ipotesi che i cambiamenti strutturali generati dal processo di liberalizzazione implicano un mutamento della tipologia di comportamento strategico adottato dalle imprese

Understanding Potential GS Risk: A Multi-Disciplinary Framework to Foster Responsible Stewardship

AbstractGeologic sequestration (GS) holds promise as a safe and effective approach for addressing climate change. However, concern about potential “liability” associated with GS often is cited as a significant barrier to project deployment. However, the authors contend that the term “liability” is poorly defined and conflates concerns about the uncertainty in the timing and magnitude of potential damages with the call for long-term stewardship of certified closed sites. This paper offers an analytic framework predicated on the use of risk-based probabilistic modeling to assist stakeholders in evaluating the potential environmental, human health and financial consequences of GS projects. Use of this framework will inform siting decisions for specific GS projects and provide maximum loss values and probabilistic estimates of expected loss values that can inform policy discussions addressing the “liability” issue

Landscape and Environmental Impact Evaluation of Roundabouts

The interest of researchers and practitioners on roundabout solutions has been growing increasingly in the last decades. The often large areas occupied by this type of intersections require special attention on the use of ground and the preservation of the natural, environmental and architectural heritage. This aim also presents the opportunity for evaluating their impact on the landscape and environment. The paper proposes a new method developed for roundabout evaluation (but generalizable to other infrastructures and fields) borrowed from building technology and based on the needs, requirements and performance expected from an object rather than on prescriptions for and descriptions of its dimensions and quality. Applications on two roundabouts are presented in order to highlight practical developments. Their final evaluation sheets are presented and through them it is relatively easy to single out the problems and drawbacks of the roundabouts from the landscape point of view

Case studies of landscape and environmental impact evaluation of roundabouts

This paper is a follow-up to a previous one that presented a new method for evaluating the landscape and environmental impact of roundabouts borrowed from building technology and based on the needs, requirements and performance expected from an object rather than on prescriptions for and descriptions of its dimensions and quality. The proposed method aims at defining criteria to set up an information structure based on a need and performance approach capable of evaluating impacts on the landscape and environmental integration. After a brief résumé of the above-mentioned principles, two applications are presented in order to highlight two practical developments. The roundabouts on which the applications are focused are located in an urban and in a rural environment respectively in the Northern part of Italy. Obviously their analysis cannot be considered comprehensive of all possible cases but it covers a large proportion of them. Differences between the two roundabouts are many and they concern, besides the landscape and environment, geometrical dimensions, type of flow, presence of weekday users (pedestrians and bikers). The final evaluation sheets are presented and through them it is relatively easy to single out the problems and drawbacks of the roundabouts from the landscape point of view

Hydrologic and landscape changes in the Middle Ebro River (NE Spain): Implications for restoration and management

The changes of landscape (1927–2003), discharge regime and anthropic activities with the river-floodplain of one reach at the Middle Ebro River (NE Spain) were investigated with the objective to identify the factors that best explain the natural ecotope succession and propose a realistic restoration option with consideration of the landscape dynamics during the last century and the socio-economic context. Our results indicate that hydrological and landscape patterns have been dramatically changed during the last century as a consequence of human alteration of the fluvial dynamics within the studied reach. The magnitude and variability of river discharge events have decreased at the end of the last century, and flood protection structures have disrupted the river floodplain connectivity. As a result, the succesional pathways of riparian ecotopes have been heavily modified because natural rejuvenation no longer takes place, resulting in decreased landscape diversity. It is apparent from these data that floodplain restoration must be incorporated as a significant factor into river management plans if a more natural functioning wants to be retrieved. The ecotope structure and dynamics of the 1927–1957 period should be adopted as the guiding image, whereas current hydrologic and landscape (dykes, raised surfaces) patterns should be considered. Under the current socio-economic context, the more realistic option seems to create a dynamic river corridor reallocating dykes and lowering floodplain heights. The extent of this river corridor should adapt to the restored flow regime, although periodic economic investments could be an option if the desired self-sustained dynamism is not reached.The research was funded by the Department of the Environmental Science, Technology and University –Aragon government (Research group E-61 on Ecological Restoration)- and MEC (CGL2005-07059). The Spanish Research Council (CSIC) granted Alvaro Cabezas through the I3P program (I3P-EPD2003-2), which was financed by European Social Funds (UE).Peer reviewe

Hydrologic and landscape changes in the Middle Ebro River (NE Spain): implications for restoration and management

The changes of landscape (1927–2003), discharge regime and anthropic activities with the river-floodplain of one reach at the Middle Ebro River (NE Spain) were investigated with the objective to identify the factors that best explain the natural ecotope succession and propose a realistic restoration option with consideration of the landscape dynamics during the last century and the socio-economic context. Our results indicate that hydrological and landscape patterns have been dramatically changed during the last century as a consequence of human alteration of the fluvial dynamics within the studied reach. The magnitude and variability of river discharge events have decreased at the end of the last century, and flood protection structures have disrupted the river floodplain connectivity. As a result, the succesional pathways of riparian ecotopes have been heavily modified because natural rejuvenation no longer takes place, resulting in decreased landscape diversity. It is apparent from these data that floodplain restoration must be incorporated as a significant factor into river management plans if a more natural functioning wants to be retrieved. The ecotope structure and dynamics of the 1927–1957 period should be adopted as the guiding image, whereas current hydrologic and landscape (dykes, raised surfaces) patterns should be considered. Under the current socio-economic context, the more realistic option seems to create a dynamic river corridor reallocating dykes and lowering floodplain heights. The extent of this river corridor should adapt to the restored flow regime, although periodic economic investments could be an option if the desired self-sustained dynamism is not reached

Hierarchical priority setting for restoration in a watershed in NE Spain, based on assessments of soil erosion and ecosystem services

31 páginas[EN] Maintaining and enhancing ecosystem services through the restoration of degraded ecosystems have become an important biodiversity conservation strategy. Deciding where to restore ecosystems for the attainment of multiple services is a key issue for future planning, management, and human well-being. Most restoration projects usually entail a small number of actions in a local area and do not consider the potential benefits of planning restoration at broad regional scales. We developed a hierarchical priority setting approach to evaluate the performance of restoration measures in a semiarid basin in NE Spain (the Martín River Basin, 2,112 km2). Our analysis utilized a combination of erosion (a key driver of degradation in this Mediterranean region) and six spatially explicit ecosystem services data layers (five of these maps plotted surrogates for soil retention and accumulation, water supply and regulation, and carbon storage, and one plotted a cultural service, ecotourism). Hierarchical maps were generated using a geographic information system that combined areas important for providing a bundle of ecosystem services, as state variables, with erosion maps, as the disturbance or regulatory variable. This was performed for multiple scales, thereby identifying the most adequate scale of analysis and establishing a spatial hierarchy of restoration actions based on the combination of the evaluation of erosion rates and the provision of ecosystem services. Our approach provides managers with a straightforward method for determining the spatial distribution of values for a set of ecosystem services in relation to ecological degradation thresholds and for allocating efforts and resources for restoration projects in complex landscapes.This work was funded by Endesa S.A. through the collaborative agreement Endesa-CSIC for scientific research. The first author wants to thank Belinda Reyers for the fruitful conversation and helpfulness showed in every moment and two anonymous referees for their constructive suggestions. M. Trabucchi was in receipt of grant from JAE-DOC Program for Advanced Study financed by the European Social Fund (ESF), Ref. I3P-BPD-2006.Peer reviewe

Efficacy of SSRIs on cognition of Alzheimer's disease patients treated with cholinesterase inhibitors.

Background: This study examines the joint effect on cognition of selective serotonin re-uptake inhibitors (SSRIs) and cholinesterase inhibitors (AChEIs) in depressed patients affected by Alzheimer’s disease (AD) living at home. Methods: The study was conducted in two different outpatient neurological clinics. 338 patients with probable ADwere treated with ChEis (donepezil, rivastigmine and galantamine) as per the clinician’s judgment and were observed for nine months. At study entry, participants underwent a multidimensional assessment evaluating cognitive, functional and psychobehavioral domains. All patients were evaluated at baseline, after one (T1), three (T2) and nine months (T3). Patients were grouped in three different categories (patients not depressed and not treated with SSRIs, patients depressed and treated with SSRIs, and patients depressed but not treated with SSRIs). Results: At baseline 182 were diagnosed as not depressed and not treated with SSRIs, 66 as depressed and treated with SSRIs, and 90 as depressed but not treated with SSRIs. The mean change in MMSE score from baseline to nine months showed that depressed patients not treated worsened in comparison with those not depressed and not treated with SSRIs (mean change −0.8±2.3 vs 0.04±2.9; p = 0.02) and patients depressed and treated with SSRI (mean change −0.8±2.3 vs 0.1±2.5; p = 0.03). Conclusions: In AD patients treated with AChEIs, SSRIs may exert some degree of protection against the negative effects of depression on cognition