Strong behavioural defensive responses of endemic Rana latastei tadpoles induced by a native predator's odour

Prey species must constantly acquire information on predator identity, abundance and dangerousness from the environment. In aquatic habitats, this information is mainly propagated by water-borne chemical signals, either predator-specific odours or prey alarm cues. Anuran larvae innately respond to conspecific alarm cues and are able to associate them to predator cues during their lifetime. In this study, we investigated the anti-predatory responses of endemic Italian agile frog (Rana latastei) tadpoles exposed to either conspecific or heterospecific alarm cues and a native predator's (Anax imperator larvae) odour. Pre-and post-stimulus behaviours of each tadpole were recorded by a digital camera and analysed by a source executable software for image-based tracking. We found that Italian agile frog tadpoles responded to fasted dragonfly odour by strongly reducing their activity, both in terms of the amount of time they spent active and path length covered in comparison to control groups. Contrary to previous studies, predators' diet had a negligible effect on tadpole response and our experiment did not bring any evidence of the phylogenetic-relatedness hypothesis. The innate or early-in-development recognition of dragonfly larvae is clearly adaptive and may increase tadpole survival with relatively low costs, but, at the same time, may increase the risk of ignoring novel potential threats.     

Volatile chemical composition does not support a native status of the cryptogenic Bupleurum fruticosum (Apiaceae) in peninsular Italy

Cryptogenic (or doubtfully native) species could have relevant implications in biogeography and in nature conservation. Bupleurum fruticosum is native in Sicily, Sardinia, and Liguria, whereas the single Tuscan population is considered cryptogenic. Given its pharmacological activity, several studies investigated the essential oil composition of this species, but an analysis of geographic pattern of the chemical composition was never performed. In the present study, the essential oil composition of the Tuscan population was investigated for the first time, and a comparison with other populations from literature was performed in order to provide useful data to disentangle its cryptogenic status. Our results highlight a major similarity of plants from Tuscany with geographically distant populations from Portugal and France, whereas other Italian populations show a very different chemical composition. These results do not support a native status of Tuscan population, suggesting an ancient human introduction. Our analysis also revealed a high percentage of (Z)-β-ocimene in stems of plants from Tuscany.     

Effects of pH and salt concentration on the siRNA binding activity of the RNA silencing suppressor protein p19

The RNA silencing pathway is an important component of the anti-viral immune response in eukaryotes, particularly in plants. In turn, many viruses have evolved mechanisms to evade or suppress this pathway. Tombusviruses such as the Carnation Italian ringspot virus (CIRV) express a 19kDa protein (p19) that is a suppressor of RNA silencing in infected plants. This protein acts as a dimer and binds specifically to short-interfering RNA (siRNA) through electrostatic interactions between charged residues in the binding cleft. Since pH and salt concentrations can vary widely from host to host, we have investigated the influence of these parameters on the siRNA binding activity of CIRV p19. Previously, we established a convenient fluorescence-based method for assaying CIRV p19:siRNA binding using Ni(2+)-NTA coated 96-well plates. Using this method, we observe that the CIRV p19 protein binds to siRNA with nanomolar affinity and that this binding is sensitive to pH and salt concentration. The pH-dissociation constant profile shows that CIRV p19:siRNA binding is dependent on three different apparent pK(a) values. The values extrapolated from the curve are 7.1, 8.0 and 10.6 that we interpret as the ionization of one or more histidine, cysteine and lysine residues, respectively. We find that the optimal suppression of RNA silencing by CIRV p19 occurs in the pH range from 6.2 to 7.6.     

Vegetational changes and human presence in the low-alpine and subalpine zone in Val Febbraro,upper Valle di Spluga (Italian central Alps), from the Neolithic to the Roman period

An interdisciplinary palaeoecological study in the low-alpine and subalpine zones of Val Febbraro, upper Valle di Spluga (Italy), between 1830 and 2304 m a.s.l., suggests the temporary presence of early Neolithic groups at about 6000 uncal b.p. Evidence for local woodland clearance and charcoal dust were found. Phases of woodland and treeline disturbances, and indications of increased human presence are evident at about 5500, 5100, and 4000 b.p. A marked increase in disturbance, mainly related to pasturing, is dated to the beginning of the Bronze Age. The last major stage of human impact on the vegetation coincides with the Final Bronze phase and the beginning of the Iron Age, with a small temporary reduction during the Roman period. ¹⁴C dated archaeological sites and finds are broadly concordant with the phases of human impact on the vegetation. A summary figure is presented. No locally significant climatic changes have been traced during the last 6000 years, and if present, they are probably overshadowed by the vegetational changes caused by human activity. Communicated by F. Bittmann     

Enhancing Nutritional Quality of Silage by Fermentation with Lactobacillus plantarum

The present study was aimed to investigate the nutritive profiles, microbial counts and fermentation metabolites in rye, Italian rye-grass (IRG) and barley supplemented with Lactobacillus plantarum under the field condition, and its probiotic properties. After preparation of silage, the content of crude protein (CP), crude ash, acid detergent fiber (ADF), and neutral detergent fiber (NDF), microbes such as lactic acid bacteria (LAB), yeast and fungi counts, and fermentation metabolites lactic acid, acetic acid and butyric acid was assessed. Results indicated that the content of ADF and NDF were significantly varied between rye, IRG and barley mediated silages. The content of CP was increased in L. plantarum supplemented with IRG, but slightly decreased in rye and barley mediated silages. The maximum LAB count was recorded at 53.10 × 10⁷ cfu/g in rye, 16.18 × 10⁷ cfu/g in IRG and 2.63 × 10⁷ cfu/g in barley silages respectively. A considerable number of the yeasts were observed in the IRG silages than the rye silages (P < 0.05). The amount of lactic acid production is higher in L. plantarum supplemented silages as compared with control samples (P < 0.05). It was confirmed that higher amount of lactic acid produced only due to more number of LAB found in the silages. L. plantarum was able to survive at low pH and bile salt and the duodenum passage with the highest percentage of hydrophobicity. Furthermore, the strain was sensitive towards the antibiotics commonly used to maintain the microbes in food industrial setups. In conclusion, supplementation of L. plantarum is most beneficial in rye, IRG and barley silage preparations and probiotic characteristics of L. plantarum was an intrinsic feature for the application in the preparation of animal feeds and functional foods.     

Height and BMI of Italian immigrants to the USA, 1908–1970

We analyze self-reported anthropometric data pertaining to 2140 adults who emigrated to the United States, mainly from southern Italy, between 1908-1928 and 1960-1970. The mean height of immigrant men was 165.5 cm: they were taller than contemporary southern Italian men by 0.5-7.3 cm in different periods. The mean height of the Italian immigrant women born before 1952 was 157.6 cm, less than the national average. At the end of the 1990s, national women average height was 162 cm, 159.5 cm for southern women. There were age-related increases of weight and BMI: overweight was more prevalent in the 40-49 years age category. In the male sample, the mean values of BMI were within the overweight range in all age classes. The prevalence of obesity was higher in the male sample than among US men, whereas it was virtually identical in the women's sample and much higher than the values reported for several European countries for the period 1970-1980.     

Verification of the turn at positions 22 and 23 of the β-amyloid fibrils with Italian mutation using solid-state NMR

The aggregation of 42-mer amyloid β (Aβ42) plays a central role in the pathogenesis of Alzheimer’s disease. Our recent research on proline mutagenesis of Aβ42 suggested that the formation of a turn structure at positions 22 and 23 could play a crucial role in its aggregative ability and neurotoxicity. Since E22K-Aβ42 (Italian mutation) aggregated more rapidly and with more potent neurotoxicity than wild-type Aβ42, the tertiary structure at positions 21–24 of E22K-Aβ42 fibrils was analyzed by solid-state NMR using dipolar-assisted rotational resonance (DARR) to identify the ‘malignant’ conformation of Aβ42. Two sets of chemical shifts for Asp-23 were observed in a ratio of about 2.6:1. The 2D DARR spectra at the mixing time of 500 ms suggested that the side chains of Asp-23 and Val-24 in the major conformer, and those of Lys-22 and Asp-23 in the minor conformer could be located on the same side, respectively. These data support the presence of a turn structure at positions 22 and 23 in E22K-Aβ42 fibrils. The formation of a salt bridge between Lys-22 and Asp-23 in the minor conformer might be a reason why E22K-Aβ42 is more pathogenic than wild-type Aβ42.     

The long history of Cannabis and its cultivation by the Romans in central Italy, shown by pollen records from Lago Albano and Lago di Nemi

The cores from the Albano and Nemi lakes, near Rome, were studied within the European Union funded PALICLAS project and provided high resolution records of the Late-glacial and Holocene. Pollen evidence of increasing human influence on vegetation was recorded in the Holocene parts of both diagrams, and the Cannabis (hemp) curve was one of the major signs. In this paper we present unambiguous pollen evidence from the Cannabaceae records for the cultivation of hemp in central Italy by the Romans. The oldest records of Cannabis and Humulus (hop) date from to the Late-glacial. Hop pollen values rise during the mid Holocene, while hemp pollen becomes more abundant from ca. 3000 cal B.P. onwards. The highest earliest hemp peak (21%) is dated to the 1st century A.D. This ‘Cannabis phase’, with the abrupt rise of hemp pollen soon after the rise of cultivated trees (Castanea, Juglans and Olea) is associated with the increase in cereals and ruderal plants. This unambiguous proof of cultivation by Romans around 2000 B.P. occurs as well as a long lasting pre-Roman presence of hemp in the area, which is natural and possibly also anthropogenic. Subsequent clear episodes of cultivation in the medieval period were found. Received February 4, 2002 / Accepted September 13, 2002 Correspondence to: Anna Maria Mercuri, e-mail: mercuri.annamaria@unimo.it