378 research outputs found

    Sviluppo e sperimentazione di una rete wireless di sensori di traffico veicolare

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    Sviluppo e sperimentazione di una rete wireless di sensori di traffico veicolar

    Climate change promotes hybridisation between deeply divergent species

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    Rare hybridisations between deeply divergent animal species have been reported for decades in a wide range of taxa, but have often remained unexplained, mainly considered chance events and reported as anecdotal. Here, we combine field observations with long-term data concerning natural hybridisations, climate, land-use, and field-validated species distribution models for two deeply divergent and naturally sympatric toad species in Europe (Bufo bufo and Bufotes viridis species groups). We show that climate warming and seasonal extreme temperatures are conspiring to set the scene for these maladaptive hybridisations, by differentially affecting life-history traits of both species. Our results identify and provide evidence of an ultimate cause for such events, and reveal that the potential influence of climate change on interspecific hybridisations goes far beyond closely related species. Furthermore, climate projections suggest that the chances for these events will steadily increase in the near future

    Effect of suckling management on productive performance and carcass traits of Comisana lambs.

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    The effect of restricted suckling on productive performance and carcass traits of growing lambs was determined. Twenty-one naturally sucked male Comisana lambs were divided into three equal weight groups with differing suckling management systems: 1) only maternal milk (C); 2) only maternal milk until 15 d of age and, from 16 d of age to slaughter, maternal milk, concentrate and hay ad libitum (T1); 3) only maternal milk until 15 d of age and, from 16 d to 30 d of age, maternal milk, concentrate and hay ad libitum, and, from 31 d of age to slaughter, only concentrate and hay ad libitum (T2). Average daily weight gain (ADG) and milk and feed intake were calculated. Ewe milk was collected from each group. At slaughter (63 d) live weight and carcass measurements were recorded. The overall mean of total milk collected was 22.7 and 41.6 kg ewe-1 for T1 and T2, respectively. Suckling management system significantly affected ADG, milk intake, dressing percentage, and percentages of intestines, stomachs, offals, and kidney fat. Suckling management appears to be an important factor affecting lamb growth and carcass quality

    Morphological traits, reproductive and productive performances of Casertana pigs reared outdoors

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    Casertana is an Italian autochthonous pig breed. In the past, the breed was common in Campania and the surrounding area in South Italy because it was valued for its productive performance, particularly regarding the fattening tendency, but in recent decades, autochthonous swine have been replaced by cosmopolitan lean-type pigs and the Casertana breed also experienced a dramatic reduction in numbers. Concern over the preservation of genetic resources and the increased demand for regional food suggest a new way of maintaining the breed. Unfortunately, few recent data on the morpho- logical as well as on the productive traits are available. To ascertain the characteristics of the Casertana breed a pro- ductive trial was performed by comparing Casertana and Large White pure breed and their cross. Sixteen females and 6 males of pure breed Casertana and 18 females and 2 males of pure breed Italian Large White were mated twice to pro- duce Casertana, Large White and Casertana x Large White piglets. The average number of piglets born was significant- ly lower in Casertana gilts, but no difference in the number of weaned piglets among genetic types was observed. Sixty- eight animals of the three genetic types were reared outdoors and received two distinct diets differing in energy content. Pigs were weighted individually every month to calculate average daily gain. Morphological traits of Casertana pigs were also recorded. A total of 54 animals (21 Casertana at 151 kg live weight, 15 crossbreed at 157 kg live weight and 18 Large White at 179 kg live weight) were slaughtered and data on carcasses were collected. Average daily weight gain differed markedly (P< 0.05) among genetic types (450; 552; 695 g/d, respectively for Casertana; Casertana x Large White; Large White) and consequently the slaughter weight also differed. Casertana showed higher dressing percentages that the Italian Large White (P< 0.05). Backfat thickness was also clearly affected by genetic type (P< 0.05): Casertana pigs had the highest value (44.91 mm). The diet had no influence on the average daily weight gain and backfat thick- ness. However, pigs fed with higher energy component had higher (P< 0.05) dressing percentage

    Drilling down hotspots of infraspecific diversity to bring them into on-ground conservation of threatened species

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    Unprecedented rates of biodiversity loss raise the urgency for preserving species ability to cope with ongoing global changes. An approach in this direction is to target intra-specific hotspots of genetic diversity as conservation priorities. However, these hotspots are often identified by sampling at a spatial resolution too coarse to be useful in practical management of threatened species, hindering the long-appealed dialog between conservation stakeholders and conservation genetic researchers. Here, we investigated the spatial and temporal variation in species presence, genetic diversity, as well as potential risk factors, within a previously identified hotspot of genetic diversity for the endangered Apennine yellow-bellied toad Bombina pachypus. Our results show that this hotspot is neither a geographically homogeneous nor a temporally stable unit. Over a time-window spanning 10–40 years since previous assessments, B. pachypus populations declined in large portions of their hotspot, and their genetic diversity levels decreased. Considering the demographic trend, genetic and epidemiological data, and models of current and future climatic suitability, populations at the extreme south of the hotspot area still qualify for urgent in-situ conservation actions, whereas northern populations would be better managed through a mix of in-situ and ex-situ actions. Our results emphasize that identifying hotspots of genetic diversity, albeit an essential step, does not suffice to warrant on-ground conservation of threatened species. Hotspots should be analyzed at finer geographic and temporal scales, to provide conservation stakeholders with key knowledge to best define conservation priorities, and to optimize resource allocation to alternative management practices
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