4,456 research outputs found
Narrowing the US twin deficits: simulations with a world macroeconometric model
In this paper we extend the macroeconometric model developed in Bagnai (2004) by linking it to a submodel for the Japanese economy, and we utilize this extended model to investigate several hypotheses of reduction in the US twin deficits. The Japanese submodel is specified and estimated along the lines set out in Bagnai and Carlucci (2003), using the “cointegration with endogenous structural break” estimation method of Gregory and Hansen (1996). The estimation results show that the Japanese economy underwent a major structural change after the first oil-price shock. The “twin deficits” simulations consider two policy instruments: a US dollar exchange rate devaluation, and a fiscal consolidation, carried out through a decrease in US government consumption. We analyze both different sizes and different timing of these policy measures, as well as their interactions, in order to evaluate their effectiveness, and the costs they impose on the partner countries (in particular, on the Euro area and Japan).twin deficits, structural break, econometric model, Japan, EMU, USA
Fish parasites resolve the paradox of missing coextinctions.
Models of coextinction identify parasites as one of the most menaced ecological groups. The number of host species a parasite uses should strongly affect its risk of coextinction. The naïve expectation is that the lower the number, the higher is the parasite's risk of being left with no hosts. Here we analyse the coextinction risk of 12,141 fish parasite species and find that highly specific parasites are not the most endangered, because they tend to use hosts with low vulnerability to extinction. This unexpected result may explain why the number of documented host-parasite coextinctions is much lower than predicted by theoretical studies. © 2013 Macmillan Publishers Limited. All rights reserved
PPARγ and Oxidative Stress: Con(β) Catenating NRF2 and FOXO
Peroxisome-proliferator activator receptor γ (PPARγ) is a nuclear receptor of central importance in energy homeostasis and inflammation. Recent experimental pieces of evidence demonstrate that PPARγ is implicated in the oxidative stress response, an imbalance between antithetic prooxidation and antioxidation forces that may lead the cell to apoptotic or necrotic death. In this delicate and intricate game of equilibrium, PPARγ stands out as a central player devoted to the quenching and containment of the damage and to foster cell survival. However, PPARγ does not act alone: indeed the nuclear receptor is at the point of interconnection of various pathways, such as the nuclear factor erythroid 2-related factor 2 (NRF2), Wnt/β-catenin, and forkhead box proteins O (FOXO) pathways. Here we reviewed the role of PPARγ in response to oxidative stress and its interaction with other signaling pathways implicated in this process, an interaction that emerged as a potential new therapeutic target for several oxidative-related diseases
Nestedness for Dummies (NeD): A User-Friendly Web Interface for Exploratory Nestedness Analysis
Recent theoretical advances in nestedness analysis have led to the introduction of several alternative metrics to overcome most of the problems biasing the use of matrix 'temperature' calculated by Atmar's Nestedness Temperature Calculator. However, all of the currently available programs for nestedness analysis lack the user friendly appeal that has made the Nestedness Temperature Calculator one of the most popular community ecology programs. The software package NeD is an intuitive open source application for nestedness analysis that can be used online or locally under different operating systems. NeD is able to automatically handle different matrix formats, has batch functionalities and produces an output that can be easily copied and pasted to a spreadsheet. In addition to numerical results, NeD provides a graphic representation of the matrix under examination and of the corresponding maximally packed matrix. NeD allows users to select among the most used nestedness metrics, and to combine them with different null models. Integrating easiness of use with the recent theoretical advances in the field, NeD provides researchers not directly involved in theoretical debates with a simple yet robust statistical tool for a more conscious performance of nestedness analysis. NeD can be accessed at http: //purl.oclc.org/ned
Robertsite: un nuovo fosfato di grotta scoperto nella Tagusan Cave(Palawan – Filippine)
La Tagusan Cave è una cavità di attraversamento che si
apre nel massiccio calcareo che ospita la famosa grotta
Porto Pricesa Undergroud River nell’isola di Palawan (Filippine).
Al suo interno sono state rivenute alcune pisoliti di
colore nero che sono state campionate e quindi analizzate
dal punto di vista tessiturale e mineralogico. Le analisi al
microscopio ottico hanno evidenziato come queste pisoliti
non siano omogenee ma siano costituite da un nucleo
spesso costituito da una aggregazione di ooliti giallastre
su cui si è depositata un’alternanza di sottili strati picei e
rossastri. L’analisi mineralogica delle bande di accrescimento
ha evidenziato la presenza, oltre a fosfati di calcio
praticamente amorfi, di robertsite [Ca2Mn3(PO4)3O2•3H2O],
un fosfato che non era mai stato segnalato prima in grotta.
Sempre in queste bande, sulla base degli esami röntgenografici
e delle analisi EDAX, si è ipotizzata la presenza
anche di janggunite [Mn5-x(Mn,Fe)1-xO8(OH)6], di cui però
non si è raggiunta la certezza. Nel nucleo invece è stato
possibile identificare la presenza di strengite-Al [(Fe,Al)
(PO4) •2H2O].
La genesi di queste particolari pisoliti è da mettere in relazione
con i processi di digestione biologica del guano che
all’inizio della loro evoluzione doveva essere abbondante
nelle acque che fluivano nella grotta, mentre ora, l’apporto
idrico è molto più scarso e proviene da stillicidi che hanno
scarsa relazione con il guano medesimo.The Tagusan cave is a hydrologic tunnel in the karst massif
hosting the famous Porto Pricesa Underground River
in the Palawan Island (Philippines). It hosts some speleothems
among which are worth to be cited some black
pearls. A few of them have been sampled to be analyzed
from the textural and mineralogical point of view.
The optical microscope analyses put in evidence that the
inner structure of these pearls is un-homogeneous, consisting
of a nucleus often made by aggregates of yellowish
oolites covered by alternated pitch-dark and reddish layers.
The mineralogical analyses find out that the growing
layers consist of amorphous phosphates and robertsite
[Ca6Mn9(PO4)9O6(H2O)6•3(H2O)], which is here recognized,
for the first time, as cave mineral. The x-ray patterns and
the EDAX analyses suggest also the presence of janggunite
[Mn5-x(Mn,Fe)1-xO8(OH)6], but no definitive proof of it
has been yet achieved. Strengite-Al, [(Fe,Al)PO4•2H2O)] is
the main component of the yellowish oolites in the pearl’s
nucleus.
The genesis of these peculiar cave pearls is strictly related
to the biological digestion processes of the guano deposits.
In fact at the beginning of their evolution the feeding
water directly crossed guano deposits, while now the
few still active dripping practically has no contact with it
A Low-cost Sensing System for Cooperative Air Quality Monitoring in Urban Areas
Air quality in urban areas is a very important topic as it closely affects the health of citizens. Recent studies highlight that the exposure to polluted air can increase the incidence of diseases and deteriorate the quality of life. Hence, it is necessary to develop tools for real-time air quality monitoring, so as to allow appropriate and timely decisions. In this paper, we present uSense, a low-cost cooperative monitoring tool that allows knowing, in real-time, the concentrations of polluting gases in various areas of the city. Specifically, users monitor the areas of their interest by deploying low-cost and low-power sensor nodes. In addition, they can share the collected data following a social networking approach. uSense has been tested through an in-field experimentation performed in different areas of a city. The obtained results are in line with those provided by the local environmental control authority and show that uSense can be profitably used for air quality monitoring
Feeding behavior of <i>Coralliophila</i> sp. on corals affected by Caribbean Ciliate Infection (CCI):A new possible vector?
Coral reefs in the Caribbean are known to be affected by many coral diseases, yet the ecology and etiology of most diseases remain understudied. The Caribbean ciliate infection (CCI) caused by ciliates belonging to the genus Halofolliculina is a common disease on Caribbean reefs, with direct contact considered the most likely way through which the ciliates can be transmitted between infected and healthy colonies. Here we report an observation regarding a Coralliophila sp. snail feeding in proximity to a cluster of ciliates forming the typical disease band of CCI. The result of this observation is twofold. The feeding behavior of the snail may allow the passive attachment of ciliates on the body or shell of the snail resulting in indirect transport of the ciliates among colonies, which makes it eligible as a possible disease vector. Alternatively, the lesions created from snail feeding may enhance the progression of the ciliates already present on the coral as well as promoting additional infections allowing pathogens to enter through the feeding scar
Assessing population collapse of Drupella spp. (Mollusca: Gastropoda) 2 years after a coral bleaching event in the Republic of Maldives
AbstractCorallivory causes considerable damage to coral reefs and can exacerbate other disturbances. Among coral predators, Drupella spp. are considered as delayer of coral recovery in the Republic of Maldives, although little information is available on their ecology. Thus, we aimed to assess their population structure, feeding behaviour and spatial distribution around 2 years after a coral bleaching event in 2016. Biological and environmental data were collected using belt and line intercept transects in six shallow reefs in Maldives. The snails occurred in aggregations with a maximum of 62 individuals and exhibited a preference for branching corals. Yet, the gastropods showed a high plasticity in adapting feeding preferences to prey availability. Drupella spp. were homogenously distributed in the study area with an average of 9.04 ± 19.72 ind/200 m2. However, their occurrence was significantly different at the reef scale with the highest densities found in locations with higher coral cover. The impact of Drupella spp. appeared to be minimal with the population suffering from the loss of coral cover. We suggest that monitoring programs collect temporal- and spatial-scale data on non-outbreaking populations or non-aggregating populations to understand the dynamics of predation related to the co-occurrence of anthropogenic and natural impacts
Les Observatoires astronomiques en Italie
In the autumn of 1863 Otto Wilhelm Struve, director of the Pulkovo Astronomical Observatory in Russia, visited most of the observatories in Italy. The report that he wrote on this occasion provides an overview on the conditions of astronomical research in Italy just after the unification of the country. Later Struve sent a French translation of his report to the Italian astronomer Giovan Battista Donati, who used it to promote the construction of the Arcetri Observatory in Florence, which was inaugurated in 1872. We present here a transcription of the French translation of Struve’s report and the transcription of a letter written by him in support of Donati’s project
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