1,721,004 research outputs found
One, no one, or one hundred thousand: how many wolves are there currently in Italy?
No full textLarge carnivores in Italy and other European countries are protected by law to ensure their long-term conservation. Estimates of abundance and demographic trends of their populations are crucial for implementing effective conservation and management strategies. However, it is challenging to obtain basic demographic parameters for elusive species such as the wolf (Canis lupus). Monitoring wolf populations by standard field methods or non-invasive genetic approaches requires huge human efforts and may be exceedingly expensive on a nation-wide scale. Aiming to obtain a first approximate estimate of wolf distribution and abundance in Italy, we developed a systematic review procedure to analyze published data obtained from a variety of sources. We deduced relevant information on wolf presence and numbers from 20 peer-reviewed studies or official reports, and from 241 Standard Data Forms of Natura 2000 sites in Italy, referring to the period 2009–2013. We estimated the species abundance by combining the number of individuals reported in each study area with the values obtained by multiplying the estimated number of packs for the average pack size. Comparing our estimates with those previously reported, we evaluated the qualitative trend of the population for each of the two management units: Alps and Apennines. Results showed the occurrence of approximately 321 wolf packs in Italy, corresponding to 1269–1800 wolves, possibly still underestimated. The Apennine sub-population seems to be almost the double in size (with ca. 1212–1711 wolves in the period 2009–2013) compared to previous estimates (600–800 wolves between 2006 and 2011). The Alpine sub-population, despite its ongoing eastwards expansion, appears rather stable (with 57–89 wolves). Overall, the current wolf population size and trends seem favorable, although the species is still locally threatened by widespread poaching and accidents. These results represent the first estimate of abundance for the whole Italian wolf population in the last 40 years. Such information can be used to implement sound conservation strategies, especially in critical human-dominated landscapes, where conflicts with human activities and increasing rates of hybridization with free-ranging domestic dogs call for updated management plans
First results on the genetic population structure of Myotis emarginatus and Myotis capaccinii in Italy.
No full textDifferent habitat suitability models yield different least-cost path distances for landscape genetic analysis
No full textHabitat suitability models (HSMs) are used to describe and predict species distributions based on multiple ecological variables and species occurrence data. HSMs may also provide a probabilistic identification of least-cost path (LCP) distances in landscape genetics. However, while several studies used HSMs for these purposes, the performance of different HSMs in landscape genetic analysis and, therefore, the consequences of model choice have not been carefully explored. In this study, we used a large dataset of wolf genotypes (Canis lupus; n = 923) that were non-invasively sampled in the central and northern Italian Apennines and western Alps, aiming (i) to estimate LCP distances derived from ten different HSMs and (ii) to quantify the correlation between inter-individual genetic and LCP distances using three statistical procedures: partial Mantel tests, multiple regression on distance matrices (MRDM) and linear mixed effect models. All LCP distances based on HSMs explained genetic distances better than Euclidean distances, irrespective of the applied landscape genetic statistical test. However, LCP distances derived by different HSMs were significantly different (paired t-test, P ≤ 0.0001), especially between "flexible discriminant analysis" (FDA) and "boosted regression trees" (BRT) models. LCP distances derived from "factorial decomposition of Mahalanobis distances" (MADIFA) in MRDM showed the highest regression coefficient (β) with genetic distances, indicating a strong correlation between LCPs and genetic distances. Results from our case study suggest that different HSMs should be compared and model-choice procedures applied to identify the best fitting HSM in landscape genetic analysis
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
Non-invasive genetic sampling to predict wolf distribution and habitat suitability in the Northern Italian Apennines:implications for livestock depredation risk
No full textNon-invasive genetic sampling has been used to reconstruct spatial patterns of carnivore distributions, identify regions where conflicts with human activities could threaten the survival of a species, and assess the effectiveness of conservation strategies. In this study, we used detailed information on wolf (Canis lupus) and livestock distributions to infer depredation risks in a wide area of the Italian Apennines. We carried out a General Niche Environment System Factor Analysis (GNESFA) to define the potential distribution of wolves genotyped from 8565 samples collected during 12 years of non-invasive genetic monitoring in 3622 locations. Habitat suitability models indicated that the proportion of meadows, altitude, slope, roughness, and distance from human settlements were the main factors positively related to the potential wolf distribution, in contrast with the extension of cultivated fields and human settlements. Results of GNESFA were used to infer the local depredation risk, which was high in 46.9 % of the pastures, and to rank the areas where prevention tools should be used with priority. In this way, the use of often-limited financial resources for prevention could be promoted in pastures with the highest depredation risk and conflicts between husbandry and wolf presence might be mitigated.</p
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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