1,721,108 research outputs found
Heavy metals and organochlorine compounds in blood of a stranded Risso’s dolphins from Northern Adriatic Sea, Italy.
No full textPollutants play an important role in the crisis populations in dolphins. This long living mammals tend to accumulate contaminants because of the high lipidic composition of their tissues, their rank in the food chain and food preferences. Assessing pollutants concentrations can help to investigate the possible effect on the immune system and on the reproductive cycles of endangered species. Risso’s dolphin Grampus griseus is rarely present in shallow waters like Adriatic sea, where reprents about 4% of strandings (Mazzariol et al. 2007). Present work reports about the heavy metals and organochlorine compounds (organochlorine pesticides and PCBs) content in blood of a Risso’s dolphin stranded in summer 2007 in Northern Adriatic Sea. Samples were collected during rehabilitation cares and analysed with ICP-AOS and GC/MS techniques. Metals concentration found are close to those observed in a stranded Risso’s dolphin from Israel by Shohan et al. (2002) and are equal to 7.31 μg/ml for Hg, 0.05 μg/ml for Cd, 0.13 μg/ml for Pb and 0,40 for μg/ml for As. Interestingly Cu and Zn are below the limit of detection of the method. For organochlorine compounds, only some of the investigated organohalogen were detected: HCB (0.77 ng/ml), HCH (1.45 ng/ml), DDT (4.32 ng/ml). Concerning PCBs, congeners 118, 128, 157, 158, 167, 177, 180, 183, 192 and 201 were detected, always at the ng/ml level. Low levels of organochlorine compounds observed can be due to the poor conditions of the animal, who was starved and didn’t eat. This caused a loss of adipose tissue, a certain mobilisation of contaminants and their rapid excretion. The same consideration is valid for heavy metals. Actually there is a lack of comparing data and their interpretation can be speculative. Anyway, the combination of blood and tissues analysis will give more information and make these evaluation more easy
Influenza della composizione della spiaggia sul successo riproduttivo di Caretta caretta lungo la costa ionica della provincia di Reggio Calabria.
No full textLa costa ionica della provincia di Reggio Calabria è la più importante area di nidificazione della tartaruga marina Caretta caretta a livello nazionale ospitando annualmente tra il 60% e l’80% circa dei nidi deposti in Italia. Oltre alla complessa serie di posidonieti presenti nell’area marina, la linea di costa è caratterizzata da diversi habitat dunali dell’All. I. della Direttiva Habitat. Nell’ambito delle attività di conservazione e monitoraggio operate dall’associazione Caretta Calabria Conservation si è indagata la struttura dei diversi siti di deposizione conosciuti al fine di verificare potenziali influenze delle variabili geo- pedomorfiche sul successo riproduttivo di Caretta caretta. La composizione della sabbia prelevata a non oltre 1 m di distanza, e alla profondità di 40 cm, da 12 nidi monitorati è stata studiata con metodi standard per identificare la granulometria e il contenuto di sostanza organica, oltre a verificarne la colorazione mediante analisi di immagine e la capacità di trasmettere calore mediante uno specifico metodo di prova. I risultati conseguiti mostrano un certo differenziamento lungo la costa con aree specifiche con maggior contenuto in ghiaia). La colorazione, pur nelle differenze dovute alla specifica composizione percentuale e alle variazioni dimensionali, non mostra differenze significative, così come la percentuale della frazione organica. La conducibilità termica dei diversi substrati ha mostrato notevoli differenze tra i campioni analizzati, ribadendo come le variazioni del substrato, anche a breve distanza, possano influenzare in modo significativo la capacità di incubazione delle uova. Il raffronto con il successo di schiusa però non ha dato riscontri significativi così come sulla durata dell’incubazione. Rimane quindi fondamentale per il successo riproduttivo lo stato di nutrizione e la storia di ogni femmina riproduttiva e, quando necessario, l’accuratezza dei metodi di traslocazione dei nidi posti in posizioni svantaggiose, a sostegno delle azioni di conservazione avviate nell’area di studio
Locomotor activity pattern of two recently introduced non-native ungulate species in a Mediterranean habitat
No full textAcoustic monitoring of golden jackal (Canis aureus) in different habitat of Srem, Serbia
No full textThe main objective of this study was to estimate density of golden jackal population in four different habitat types of Srem region, Serbia. In this purpose, acoustic method was performed across four different transects: two along rivers - Danube and Sava, one across Fruška Gora mountain and one across croplands in central part of Srem region. In this abstract, preliminary results of our research are presented
Transmission dynamics of lyssavirus in Myotis myotis: mechanistic modelling study based on longitudinal seroprevalence data
No full textWe investigated the transmission dynamics of lyssavirus in Myotis myotis and Myotis blythii, using serological, virological, demographic and ecological data collected between 2015 and 2022 from two maternity colonies in northern Italian churches. Despite no lyssavirus detection in 556 bats sampled over 11 events by reverse transcription-polymerase chain reaction (RT-PCR), 36.3% of 837 bats sampled over 27 events showed neutralizing antibodies to European bat lyssavirus 1, with a significant increase in summers. By fitting sets of mechanistic models to seroprevalence data, we investigated factors that influenced lyssavirus transmission within and between years. Five models were selected as a group of final models: in one model, a proportion of exposed bats (median model estimate: 5.8%) became infectious and died while the other exposed bats recovered with immunity without becoming infectious; in the other four models, all exposed bats became infectious and recovered with immunity. The final models supported that the two colonies experienced seasonal outbreaks driven by: (i) immunity loss particularly during hibernation, (ii) density-dependent transmission, and (iii) a high transmission rate after synchronous birthing. These findings highlight the importance of understanding ecological factors, including colony size and synchronous birthing timing, and potential infection heterogeneities to enable more robust assessments of lyssavirus spillover risk
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Il sistema di relazioni morfoadattative del gruppo Myotis myotis/M. blythii/M. punicus nel Bacino del Mediterraneo
Full text linkBats are the second order of mammals for number of species and the cryptic diversity is still widespread among species and a hotspot in systematic and consequentially in ecology and conservation. So in many cases monitoring bats is hampered by the lack of a reliable method of identification especially by bioacoustic studies, with regards to the analysis of their echolocation calls. In this contest for example the distinction among the three species of “large Myotis”, Myotis myotis, M. blythii and M. punicus is very difficult especially by identification of ultrasound.
Target of the study is to clarify differences among the species on morphological, bioacoustic and parasitological point of view, as interpretation of the evolutionary model of these three species.
About the bioacoustic, 216 sonograms belonging to the three species were tested in different regions of the Mediterranean basin comparing the performance of quadratic and linear discriminant function analysis (DFA) of calls as a means to identify species. Data collection took place in strategic geographical contexts, which has allowed us to explore the variability of signals, exploring the impact of geographical isolation in regions such as in Sardinia and Crete where respectively only M. punicus and M. blythii are present.
The comparison within Italy and Greece, where the two species M. myotis and M. blythii are in close sympatry, and the comparison of M. punicus of Sardinia with data coming from the Maghreb (Algeria) revealed that the influence of geographic location is a strong factor only in Greece samples of M. myotis where values of all measured parameters, especially those related to frequency, deviate from the results obtained for the species in Italy and Spain. Sound parameters of M. blythii in Greece are very similar to the Italian and Cretan samples demonstrating that differences in M. myotis are not due to the sampling method.
Regarding morphometry, in Italy have been measured 217 specimens of which 152 M. myotis and 65 M. blythii; morphological comparisons between species and gender were performed, however no statistical significance was found except for the greater size of female specimens.
Regarding the ectoparasite community, among the different colonies examined there are strong differences in prevalence and intensity correlated to the diversity of host. Among the three species of large Myotis also there were very low intensity and prevalence in sample of both M. myotis and M. blythii from Tuscany, but the sample were constituted only by male suggesting, as previously published, the role of aggregation of reproductive females to increment the presence and fecundity also of ectoparasites. There are statically differences in Penicillidia dufourii, Spinturicidae e Macronissidae prevalence on the three species in which M. punicus and M. blythii show a heavier charge in the mean number of parasite per host.
During the research on ectoparasites were collected new information on morphology and ecology of Cimex pipistrelli, not common species in Italy, also about his role in the transmission of blood parasites and viruses. A new Coronavirus was described for Italy.
Actually the research provides a new perspective in the complex bioecology of the three species of large Myotis, opening new perspective in the knowledge of evolutionary model of these three species
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