Distance sampling effectively monitored a declining population of Italian roe deer Capreolus capreolus italicus

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Intercomparison of the northern hemisphere winter mid-latitude atmospheric variability of the IPCC models

We compare, for the overlapping time frame 1962-2000, the estimate of the northern hemisphere (NH) mid-latitude winter atmospheric variability within the XX century simulations of 17 global climate models (GCMs) included in the IPCC-4AR with the NCEP and ECMWF reanalyses. We compute the Hayashi spectra of the 500hPa geopotential height fields and introduce an integral measure of the variability observed in the NH on different spectral sub-domains. Only two high-resolution GCMs have a good agreement with reanalyses. Large biases, in most cases larger than 20%, are found between the wave climatologies of most GCMs and the reanalyses, with a relative span of around 50%. The travelling baroclinic waves are usually overestimated, while the planetary waves are usually underestimated, in agreement with previous studies performed on global weather forecasting models. When comparing the results of various versions of similar GCMs, it is clear that in some cases the vertical resolution of the atmosphere and, somewhat unexpectedly, of the adopted ocean model seem to be critical in determining the agreement with the reanalyses. The GCMs ensemble is biased with respect to the reanalyses but is comparable to the best 5 GCMs. This study suggests serious caveats with respect to the ability of most of the presently available GCMs in representing the statistics of the global scale atmospheric dynamics of the present climate and, a fortiori, in the perspective of modelling climate change.Comment: 39 pages, 8 figures, 2 table

Destabilization of the thermohaline circulation by transient perturbations to the hydrological cycle

We reconsider the problem of the stability of the thermohaline circulation as described by a two-dimensional Boussinesq model with mixed boundary conditions. We determine how the stability properties of the system depend on the intensity of the hydrological cycle. We define a two-dimensional parameters' space descriptive of the hydrology of the system and determine, by considering suitable quasi-static perturbations, a bounded region where multiple equilibria of the system are realized. We then focus on how the response of the system to finite-amplitude surface freshwater forcings depends on their rate of increase. We show that it is possible to define a robust separation between slow and fast regimes of forcing. Such separation is obtained by singling out an estimate of the critical growth rate for the anomalous forcing, which can be related to the characteristic advective time scale of the system.Comment: 37 pages, 8 figures, submitted to Clim. Dy

Tungstate ionic liquids as catalysts for CO2 fixation into epoxides

Herein we describe the syntheses of a series of ammonium, phosphonium, imidazolium and diazabycicloundecenium tungstate and peroxotungstate ionic liquids, their full spectroscopic characterisation (FT-IR, 1H-, 13C-and 183W-NMR) and a comparison of their properties and possible applications in catalysis. The synthetic procedures to obtain the ionic liquids rely on anion exchange and acid-base reactions – including an innovative route for the synthesis of tungstate and peroxotungstate ionic liquids using, for the first time, a halide-free organic ionic liquid as precursor. The tungstate ionic liquids were used as catalysts for CO2 fixation in styrene oxide as well as in a series of other epoxides to yield the corresponding carbonates. Under optimized conditions, styrene carbonate is obtained in up to 67 % yield at 90 °C with just butylmethylimidazolium tungstate, and in 91 % yield by coupling tetrabutylammonium tungstate and bromide. Preliminary tests indicate that the same catalysts can also promote epoxidation reactions, paving the way for their use in the direct oxidative carboxylation of olefins

A transesterification-acetalization catalytic tandem process for the functionalization of glycerol: The pivotal role of isopropenyl acetate

At 30 \ub0C, in the presence of Amberlyst-15 as a catalyst, a tandem sequence was implemented by which a pool of innocuous reactants (isopropenyl acetate, acetic acid and acetone) allowed upgrading of glycerol through selective acetylation and acetalization processes. The study provided evidence for the occurrence of multiple concomitant reactions. Isopropenyl acetate acted as a transesterification agent to provide glyceryl esters, and it was concurrently subjected to an acidolysis reaction promoted by AcOH. Both these transformations co-generated acetone which converted glycerol into the corresponding acetals, while acidolysis sourced also acetic anhydride that acted as an acetylation reactant. However, tuning of conditions, mostly by changing the reactant molar ratio and optimizing the reaction time, was successful to steer the set of all reactions towards the synthesis of either a 1\u2009:\u20091 mixture of acetal acetates (97% of which was solketal acetate) and triacetin, or acetal acetates in up to 91% yield, at complete conversion of glycerol. To the best of our knowledge, a one-pot protocol with such a degree of control on the functionalization of glycerol via transesterification and acetalization reactions has not been previously reported. The procedure was also easily reproduced on a gram scale, thereby proving its efficiency for preparative purposes. Finally, the design of experiments with isotopically labelled reagents, particularly d4-acetic acid and d6-acetone, helped to estimate the contribution of different reaction partners (iPAc/AcOH/acetone) to the formation of final products. This journal i

Nocturnal line transect sampling of wild boar (Sus scrofa) in a Mediterranean forest: long-term comparison with capture-mark-resight population estimates

Although accurate estimates of wild boar (Sus scrofa) populations are crucial for any effective resource management or pest control programme, this species is well known to be difficult to monitor. We conducted a ten-year study in a fenced Mediterranean forest (Rome, Italy) to evaluate nocturnal line transect sampling performances. We focused on its accuracy in monitoring changes in density, which was independently estimated by Capture-Mark-Resight performed on counts at feeding sites. We carried out night surveys in the autumn of 2001-2010, using portable infrared cameras to detect animals. We sampled on foot to cover the whole study area and the different habitat types evenly. However, to ensure safe working conditions during night and to limit disturbance, we placed transects along paths and forest roads. Therefore, we investigated the potential impact of our convenience sampling on the detection process, using radiolocations of wild boars to assess their distribution with respect to selected transects. We found that our survey design should not have biased our estimates and that densities and coefficients of variations from line transect sampling were consistent with CMR results. Although labour-intensive, we believe that our approach can improve wild boar monitoring effectively, even in concealing habitats, providing decision makers with accurate estimates (and quantified confidence limits) which can help to develop the most appropriate management programme. Moreover, the current low price of new-generation infrared cameras can also increase strongly the cost-effectiveness of this method