1,720,954 research outputs found
Impact of Wolf on livestock in Northern Italy and prediction of predation risk
No full textMortality due to illegal killing by humans is still today one of the main risk factors for the wolf (Canis lupus) and the effective management of conflict between wolves and livestock breeding is a great concern for species conservation. We assessed the impact of wolf on livestock in an area of Northern Apennines analyzing data provided by the Provincial Administration of Piacenza and additional data directly collected through interviews to farmers during the period 2005-2012. We recorded : i) the number of farms that have suffered predation (classified by : livestock species, productive orientation, rearing method, level of surveillance and preventive methods), ii) the number of predation events and the number of preyed animals. The effects of management factors were evaluated by Likelihood Ratio (exact test with permutation) as regard the frequencies of predation and by Multifactorial Analysis of Variance as regard the average number of heads preyed upon for each event of predation. By Regression and Curve-fit Analyses we evaluated the relationships between the number of predation events and of the number of animals preyed and 21 variables characterizing the grazing areas. Then we formulated a predictive model of the predation probability,
through a forward stepwise Binary Logistic Regression Analysis with pasture characteristics as predictors. Livestock species, productive orientation, rearing and preventive methods resulted the most important factors affecting the frequency of predation events and the number of preyed animals. The average number of preyed heads per event increased during the study period and was greater for sheep than other species. The number of predation events showed significant
relationship with the pasture slope, the percentage of mixed deciduous forest, the percentage of total deciduous forest and the distance from villages. The number of preyed animals was significantly related with the pasture exposure and with the percentage of mixed deciduous forests.
In the model of predation risk entered the rearing methods, the shape index and the percentage of coniferous forest cover, both with a negative effect on the predation probability, whereas exposure
had a positive effect. 33.3% of the pastures resulted at low predation risk (Probability of predation = 0.0 - 0.3), 4.2% at medium predation risk (Probability of predation = 0.3 - 0.6), and 62.5% at high
predation risk (Probability of predation > 0.6). Overall, 64.6% of the pastures were potentially at risk of predation (Probability of predation > 0.5)
Wolf habitat suitability in an area of Northern Apennines : a multimodel approach
No full textThe Italian wolf population was near to the extinction at the beginning of the seventies of the past century, owing to indiscriminate hunting and poisoning. In 1972 the wolf was named protected species and since this moment the recolonization of the Italian Peninsula has begun, starting
from the remaining part of the range in Southern and Central Italy and reaching the Northern Apennines (N-Italy) during the eighties. This study was aimed to individuate suitable areas for wolves in the provinces of Pavia and Piacenza, that include a trait of the Apennines chain that
links the more extended wolf areas in Emilia-Romagna and Tuscany to those of Liguria and Western Alps and where wolves suffer a high mortality due to illegal killings and accidents. From August 2011 to August 2012 we searched for wolf and wild ungulate signs of presence on 25 transect (total length 168 km) covered once a season and randomly located in an 860 km2 study area. We split the study area in 4-km2 cells by a grid spaced of 2 km and in each cell we measured the variables concerning altimetry, exposure, slope, and land use. We classified the cells crossed by transects as presence cells if wolf signs were found at least in a season and absence ones if no signs were found. We formulated habitat suitability models following an approach use vs.
availability by Binary Logistic Regression Analysis (BLRA), Ecological Niche Factor Analysis (ENFA) and Maximum Entropy algorithm (MaxEnt) and by comparing presence cells with an equal number of randomly selected ones. Moreover we formulated a habitat suitability model
following an approach presence vs. absence by BLRA, using only the cells crossed by transects and comparing presence cells with absence ones. For the first approach only the environmental variables were used, while for the second we used also the abundance of wild ungulates. We
validated all the models by the K-Fold cross validation and ROC curves. The best model was that resulting from BLRA with presence vs. availability approach, and it was used to create a suitability map for the whole hill and mountainous area of the two provinces (2408 km2). Potential wolf range was 736 km2, i.e. 30.5% of available area. The suitability map can be used to the accomplishment of the actions to awaken public opinion towards the cohabitation with wolves
and to plan the methods and interventions of damage prevention to the animal husbandry, so reducing the conflicts between human activities and wolf presence. Moreover on the basis of the habitat suitability map a network of protected areas can be designed to improve wolf protection
and conservation policy
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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