Prediction of minimum temperatures in an alpine region by linear and non-linear post-processing of meteorological models

International audienceModel Output Statistics (MOS) refers to a method of post-processing the direct outputs of numerical weather prediction (NWP) models in order to reduce the biases introduced by a coarse horizontal resolution. This technique is especially useful in orographically complex regions, where large differences can be found between the NWP elevation model and the true orography. This study carries out a comparison of linear and non-linear MOS methods, aimed at the prediction of minimum temperatures in a fruit-growing region of the Italian Alps, based on the output of two different NWPs (ECMWF T511?L60 and LAMI-3). Temperature, of course, is a particularly important NWP output; among other roles it drives the local frost forecast, which is of great interest to agriculture. The mechanisms of cold air drainage, a distinctive aspect of mountain environments, are often unsatisfactorily captured by global circulation models. The simplest post-processing technique applied in this work was a correction for the mean bias, assessed at individual model grid points. We also implemented a multivariate linear regression on the output at the grid points surrounding the target area, and two non-linear models based on machine learning techniques: Neural Networks and Random Forest. We compare the performance of all these techniques on four different NWP data sets. Downscaling the temperatures clearly improved the temperature forecasts with respect to the raw NWP output, and also with respect to the basic mean bias correction. Multivariate methods generally yielded better results, but the advantage of using non-linear algorithms was small if not negligible. RF, the best performing method, was implemented on ECMWF prognostic output at 06:00 UTC over the 9 grid points surrounding the target area. Mean absolute errors in the prediction of 2 m temperature at 06:00 UTC were approximately 1.2°C, close to the natural variability inside the area itself

Estimating abundance and habitat suitability in a micro-endemic snake: the Walser viper

Recently described species suffer lack of information that hampers setting up appropriate conservation strategies. The situation is particularly complex with micro-endemic snakes, for which detection and monitoring are particularly challenging. The Walser viper Vipera walser is a recently described snake inhabiting a small area of the SW Italian alps. We combined information on species distribution with repeated monitoring to identify the areas most suitable for the species, and to obtain estimates of species abundance. Species distribution models were used to identify the topographical, climatic, and land-cover features related to the occurrence of vipers. Furthermore, repeated transects and N-mixture models were used to estimate abundance and to identify factors related to the variation of abundance. The available data suggested that the species has a disjunct range, with a Northern range of ~45 km2 , and a southern range of ~225 km2. Distribution models suggested that vipers are associated with areas with open egetation,altitude between 1300 and 2300 m, high precipitation, low forest cover, low slope, and southern aspect. N-mixture models confirmed very low detection probability of these vipers, and suggested that the species has a low abundance,with the highest abundance in south-facing plots. We provide the first quantitative information on habitats and abundance variation for Walser vipers. The broad confidence intervals of abundance estimates exemplify the complexity of providing range-wide measures of abundance for secretive species. Given the narrow range of these vipers, continuous monitoring is required to understand how they respond to ongoing environmental changes in mountainous areas

A new vertebrate for Europe: the discovery of a range-restricted relict viper in the western Italian Alps

We describe Vipera walser, a new viper species from the north-western Italian Alps. Despite an overall morphological resemblance with Vipera berus, the new species is remarkably distinct genetically from both V. berus and other vipers occurring in western Europe and shows closer affinities to species occurring only in the Caucasus. Morphologically, the new species appear to be more similar to V. berus than to its closest relatives occurring in the Caucasus, but can be readily distinguished in most cases by a combination of meristic features as confirmed by discriminant analysis. The extant population shows a very low genetic variability measured with mitochondrial markers, suggesting that the taxon has suffered a serious population reduction/bottleneck in the past. The species is extremely range-restricted (less than 500 km2) and occurs only in two disjunct sites within the high rainfall valleys of the Alps north of Biella. This new species should be classified as globally ‘endangered’ due to its small and fragmented range, and an inferred population decline. The main near-future threats to the species are habitat changes associated with reduced grazing, along with persecution and collecting

From cylindrical to non‐cylindrical foreland basin: Pliocene–Pleistocene evolution of the Po Plain–Northern Adriatic basin (Italy)

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Museum specimens indicate genetic erosion in an endangered lizard

Genetic variability, one of the main factors that guarantees species persistence, and species’ conservation status are generally evaluated with indices calculated at the present time. Natural history collections might help compare historical and current genetic diversity so to identify major trends. Here we analysed museum specimens of the lizard Zootoca vivipara carniolica, with a specific and stringent protocol for degraded DNA, in order to contrast its past and current genetic variability, using fragments of one mitochondrial DNA gene. Part of the distributional range of Z. v. carniolica (Po Plain, Italy), heavily impacted by human activities, was investigated. We found two previously unknown haplotypes in populations that are extinct today, suggesting the loss of these haplotypes and thus an overall shrinking of genetic variability. We argue that these results, together with the increasing threats posed by climate and land use changes, suggest that specific conservation measures for the persistence of Z. v. carniolica in Northern Italian lowlands have to be considere

A new method for free testosterone assay: clinical evaluation.

The Authors propose a new direct method for the determination of free Testosterone (F.Te). Our study was made following this method: 1) on a control group composed of 12 healthy men and 21 healthy women, and 2) on a group of 29 patients suffering from Polycystic Ovary Syndrome (PCOS) with clinical signs of hyperandrogenism. This pathological group presented acne and hirsutism in 95% of the cases. The Authors demonstrate how the determination of F.Te permits a 93.1% correct endocrinological diagnosis of hyperandrogenism

A new method for free testosterone assay: clinical evaluation.

The Authors propose a new direct method for the determination of free Testosterone (F. Te). Our study was made following this method: 1) on a control group composed of 12 healthy men and 21 healthy women, and 2) on a group of 29 patients suffering from Polycystic Ovary Syndrome (PCOS) with clinical signs of hyperandrogenism. This pathological group presented acne and hirsutism in 95% of the cases. The Authors demonstrate how the determination of F