178 research outputs found

    Evaluation of drinking patterns and their impact on alcohol-related aggression: a national survey of adolescent behaviours

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    BACKGROUND: Although there have been a wide range of epidemiological studies examining the impact of patterns of alcohol consumption among adolescents, there remains considerable variability in both defining these patterns and the ability to comprehensively evaluate their relationship to behavioural patterns. This study explores a new procedure for defining and evaluating drinking patterns and integrating well-established indicators. The composite measure is then used to estimate the impact of these patterns on alcohol-related aggressive behaviour among Italian adolescents. METHODS: Data were collected as part of the 2011 European School Survey Project on Alcohol and other Drugs (ESPAD). A national sample of 14,199 students aged 15–19 years was collected using an anonymous, self-administered questionnaire completed in a classroom setting. Drinking patterns were established using principal component analysis. Alcohol-related aggression was analysed as to its relationship to patterns of drinking, behaviour of friends towards alcohol use, substance use/abuse, school performance, family relationships and leisure activities. RESULTS: Several specific drinking patterns were identified: “Drinking to Excess” (DE), “Drinking with Intoxication” (DI) and “Drinking but Not to Excess” (DNE). A higher percentage of males were involved in alcohol-related aggression compared with females. In males, the DE and DI patterns significantly increased the likelihood of alcohol-related aggression, whereas the DNE pattern was negatively associated. Similar results were found in females, although the DI pattern was not significantly associated with alcohol-related aggression. Overall, cigarette smoking, illegal drug use, truancy, limited parental monitoring, frequent evenings spent outside of the home and peer influence associated strongly with alcohol-related aggression. CONCLUSIONS: Our findings suggest that drinking patterns, as uniquely monitored with an integrated metric, can: 1) explain drinking habits better than commonly used indicators of alcohol use and 2) provide a better understanding of behavioural risks such as alcohol-related aggression. Environmental background also appears to strongly associate with this type of aggressive behaviour

    First karyological analysis of the endemic malagasy phantom gecko matoatoa brevipes (Squamata: Gekkonidae)

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    The genus Matoatoa includes two Malagasy endemic species, M. brevipes and M. spannringi. Due to their cryptic behaviour, the two species are known only from a handful of specimens and have been included in few molecular studies. Here we carried out a molecular barcoding analysis using a fragment of the mitochondrial NADH dehy-drogenase subunit 2 (ND2) and the first chromosomal analysis of M. brevipes. The molecular analysis confirmed the identity of the studied samples as M. brevipes. However, the level of genetic divergence (4% uncorrected p-distance) between our samples and other sequences of M. brevipes, suggests previously unrecognised diversity within the spe-cies. The karyotype of M. brevipes is composed of 2n = 34 chromosomes: the first pair is metacentric, while all the other pairs are telocentric and gradually decreasing in length (Arm Number, AN = 36). C-banding revealed little evidence of centromeric heterochromatin, while NOR-associated heterochromatin was found on the telomeres of a medi-um sized telocentric pair. No heteromorphic chromosome pairs were found in the karyotype of the species, suggesting that putative sex chromosomes are at an early stage of differentiation. Karyological comparisons with closely related species were performed with Christinus marmoratus, and representatives of the genera Phelsuma, Ebenavia, Paroedura and Uroplatus. Comparisons across genera suggest that chromosome diversification in this group of geckos probably occurred by means of chromosome fusions and inversions, leading to a reduction of the chromosome number and the formation of biarmed elements in different species

    Evidence of lipofuscin accumulation in the deep-water red shrimp Aristaeomorpha foliacea (Risso, 1827)

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    Lipofuscin, a non-degradable, degenerative fluorescent pigment which accumulates in post-mitotic cells, represents a promising method for ageing marine crustaceans. The presence and accumulation of lipofuscin has been studied in the deep-water red shrimp Aristaeomorpha foliacea (Risso, 1827) to assess its use as a tool for ageing larger (i.e., older) specimens and thus improve knowledge of the growth and longevity of this species. Specimens, gathered during experimental trawl surveys carried out in the Strait of Sicily (Mediterranean Sea), were stored directly on-board in 10% buffered formaldehyde solution; their brain was thereafter removed, prepared with various current histological techniques and examined with a binocular microscope. Thin sections of the olfactory lobe cell mass were also analyzed using fluorescence microscopy, and the lipofuscin concentration was measured through image analysis. Various indices were computed for each individual by pooling data from many images: number and coverage of the lipofuscin granules per unit area, and mean individual area of the granules. Lipofuscin was detected in all specimens investigated with characteristics (grain typology and dimension) strictly resembling those already described in other crustacean species. The present preliminary results encourage further studies to develop and validate a methodology based on the use of lipofuscin for improving the relative ageing of large A. foliacea shrimps

    Age estimation and growth of striped dolphins Stenella coeruleoalba stranded along the coasts of south-western Italy

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    The knowledge of demographic traits such as longevity, growth rates and age at sexual maturity is crucial for understanding the structure of a population in its natural environment and implementing appropriate strategies for its management and conservation. Based on counts of growth layer groups in sections of decalcified teeth using the paraffin technique, we estimated the age and growth of 25 individuals of striped dolphin (Stenella coeruleoalba) found dead stranded along the coast of Campania and Calabria (south Italy, central-western Mediterranean) from 2013 to 2018. Seven individuals, with TL of 100–110 cm, were calves under 1 year old. The oldest male and female individuals were 19 and 14 years old, respectively. Growth curve estimated using the Gompertz growth model (GGM) showed that in S. coeruleoalba male growth trajectories are partly in accordance with those reported in other studies on the same species from different Mediterranean areas. The high frequency (28%) of calves strongly suggests that females of this species use the marine area all around the south-western Italian coasts to give birth to their offspring. Furthermore, a comparison with the estimated age of striped dolphins from other Mediterranean marine areas shows that the longevity of the individuals examined in this study is much lower. Our study provides information toward understanding the demographic traits of S. coeruleoalba from Mediterranean Sea. The results reported here can be useful for future research aimed at understanding population structure, mortality patterns and the effects of anthropogenic activity on the survival of this species in this marine area

    Age estimation and growth of striped dolphins Stenella coeruleoalba stranded along the coasts of south-western Italy

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    The knowledge of demographic traits such as longevity, growth rates and age at sexual maturity is crucial for understanding the structure of a population in its natural environment and implementing appropriate strategies for its management and conservation. Based on counts of growth layer groups in sections of decalcified teeth using the paraffin technique, we estimated the age and growth of 25 individuals of striped dolphin (Stenella coeruleoalba) found dead stranded along the coast of Campania and Calabria (south Italy, central-western Mediterranean) from 2013 to 2018. Seven individuals, with TL of 100–110 cm, were calves under 1 year old. The oldest male and female individuals were 19 and 14 years old, respectively. Growth curve estimated using the Gompertz growth model (GGM) showed that in S. coeruleoalba male growth trajectories are partly in accordance with those reported in other studies on the same species from different Mediterranean areas. The high frequency (28%) of calves strongly suggests that females of this species use the marine area all around the south-western Italian coasts to give birth to their offspring. Furthermore, a comparison with the estimated age of striped dolphins from other Mediterranean marine areas shows that the longevity of the individuals examined in this study is much lower. Our study provides information toward understanding the demographic traits of S. coeruleoalba from Mediterranean Sea. The results reported here can be useful for future research aimed at understanding population structure, mortality patterns and the effects of anthropogenic activity on the survival of this species in this marine area

    Nothing is as it seems: genetic analyses on stranded fin whales unveil the presence of a fin-blue whale hybrid in the Mediterranean Sea (Balaenopteridae)

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    The fin whale Balaenoptera physalus is a large rorqual species occurring worldwide, mainly in temperate and subpolar zones. In contrast to many baleen whales, not all the fin whale populations show the same model of migration. In fact, migratory behaviours of this latter species range from long seasonal migration between high and low latitudes to a complete nonmigratory behaviour. A resident fin whale population was described in the Mediterranean Sea, which is also frequented by North Atlantic individuals entering through the Strait of Gibraltar in winter to feed. Between 2020 and 2021 three individuals initially identified as fin whales died along the Tyrrhenian coasts (Mediterranean Sea, Italy). Their mitochondrial DNA control region (mtDNA CR) was analysed and compared to fin whale haplotypes previously described in North Atlantic Ocean and Mediterranean Sea to identify their geographical origin. Our results show that two individuals most likely belong to the Mediterranean fin whale population, while an individual was recognised as a putative fin-blue whale hybrid (Balaenoptera physalus x Balaenoptera musculus) with a North Atlantic origin. The discovery of the first fin-blue whale hybrid in the Mediterranean Sea was confirmed by the analysis of a biparentally inherited marker, the α-lactalbumin (α-lac) nuclear gene, demonstrating that the morphological analysis alone does not allow to correctly identify hybrids, especially if intermediate characters of both parental species are not clearly distinguishable

    Life History Traits of Sperm Whales Physeter macrocephalus Linnaeus, 1758 Stranded along Italian Coasts (Cetartiodactyla: Physeteridae)

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    We investigated the relationship between age and body length, and age at sexual maturity of Physeter macrocephalus individuals stranded along the Italian coast. Our molecular analysis shows that all our samples belong to the C.001.002 haplotype, shared between Atlantic and Mediterranean populations. We show that males attain sexual maturity at 10 years, similar to those from other marine areas. However, considering the same body length class, Mediterranean males are older than Atlantic ones. Our finding of a Mediterranean pregnant female of only 6.5 m in length and an assessed age of 24–26 years is particularly noteworthy, considering that females reach sexual maturity at about 9 years and 9 m of total length in other regions. Comparing our results with the literature data, we highlight the positive correlation between lifespan, adult body length and weight of males from the Mediterranean and Atlantic Ocean. Regardless of whether the relatively small size of Mediterranean specimens is a consequence of an inbreeding depression or an adaptation to less favorable trophic conditions, we recommend to closely monitor this population from a conservation perspective. In fact, its low genetic diversity likely corresponds to a relatively limited ability to respond to environmental changes compared with other populations

    CALOCUBE: An approach to high-granularity and homogenous calorimetry for space based detectors

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    Future space experiments dedicated to the observation of high-energy gamma and cosmic rays will increasingly rely on a highly performing calorimetry apparatus, and their physics performance will be primarily determined by the geometrical dimensions and the energy resolution of the calorimeter deployed. Thus it is extremely important to optimize its geometrical acceptance, the granularity, and its absorption depth for the measurement of the particle energy with respect to the total mass of the apparatus which is the most important constraint for a space launch. The proposed design tries to satisfy these criteria while staying within a total mass budget of about 1.6 tons. Calocube is a homogeneous calorimeter instrumented with Cesium iodide (CsI) crystals, whose geometry is cubic and isotropic, so as to detect particles arriving from every direction in space, thus maximizing the acceptance; granularity is obtained by filling the cubic volume with small cubic CsI crystals. The total radiation length in any direction is more than adequate for optimal electromagnetic particle identification and energy measurement, whilst the interaction length is at least sufficient to allow a precise reconstruction of hadronic showers. Optimal values for the size of the crystals and spacing among them have been studied. The design forms the basis of a three-year R&D activity which has been approved and financed by INFN. An overall description of the system, as well as results from preliminary tests on particle beams will be described

    DIAMOND DETECTORS FOR CHARACTERIZATION OF LASER-GENERATED PLASMA

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    Abstract -CVD mono-crystalline diamond films were employed as detectors of the Introduction -Laser-generated plasma is characterized by high temperature and density
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