1,720,984 research outputs found
Annotated checklist and distribution of the Socotran Archipelago Herpetofauna (Reptilia)
No full textRazzetti, Edoardo, Sindaco, Roberto, Grieco, Cristina, Pella, Francesca, Ziliani, Ugo, Pupin, Fabio, Riservato, Elisa, Pellitteri-Rosa, Daniele, Butikofer, Luca, Suleiman, Ahmed Saeed, Al-Aseily, Badar Awadh (2011): Annotated checklist and distribution of the Socotran Archipelago Herpetofauna (Reptilia). Zootaxa 2826: 1-44, DOI: 10.5281/zenodo.27727
Climate migrants' survival threatened by "C" shaped anthropic barriers
No full textIn spite of studies on range shifts being very abundant, the problematic of dispersal barriers limiting climate migrants' movement is yet to be fully included into any modelling framework. For this reason, we introduce a novel concept whereby the interplay of range shifts and dispersal barriers of a particular spatial configuration can threaten the persistence of populations under a climate change scenario. We named this concept "C-trap", after the topographic shape of such barrier. After elaborating on the theoretical features of C-traps, we provide a simple method that combines environmental data and future climate projections to locate them spatially. As an application, we then use such method to determine where high C-trap densities have the potential to further threaten the conservation of endangered, endemic animals across the world's terrestrial realm, in a climate change scenario. Our methodology detected potential C-traps for the study system with areas of high densities mostly located in east Europe, south Asia and North America. However, finer scale analyses are required to assess the magnitude of the threat locally. Dispersal barriers add an additional dimension to range shift studies, and can ultimately prevent otherwise successful climate migrants from tracking their climatic niche. The methodology presented here is simple and flexible enough to be adapted to a wide range of taxa and locations, and to be implemented further to account for the fast development of range shift modelling. We, therefore, encourage researchers to include the effects of anthropogenic dispersal barriers in range shifts models and in the planning of effective conservation strategies with reference to climate change. This article is protected by copyright. All rights reserved
A new method for modelling biological invasions from early spread data accounting for anthropogenic dispersal
Full text linkBiological invasions are one of the major causes of biodiversity loss worldwide. In spite of human aided (anthropogenic) dispersal being the key element in the spread of invasive species, no framework published so far accounts for its peculiar characteristics, such as very rapid dispersal and independence from the existing species distribution. We present a new method for modelling biological invasions using historical spatio-temporal records. This method first discriminates between data points of anthropogenic origin and those originating from natural dispersal, then estimates the natural dispersal kernel. We use the expectation-maximisation algorithm for the first step; we then use Ripley’s K-function as a spatial similarity metric to estimate the dispersal kernel. This is done accounting for habitat suitability and providing estimates of the inference precision. Tests on simulated data show good accuracy and precision for this method, even in the presence of challenging, but realistic, limitations of data in the invasion time series, such as gaps in the survey times and low number of records. We also provide a real case application of our method using the case of Litoria frogs in New Zealand. This method is widely applicable across the field of biological invasions, epidemics and climate change induced range shifts and provides a valuable contribution to the management of such issues. Functions to implement this methodology are made available as the R package Biolinv (https://cran.r-project.org/package=Biolinv).</div
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
Hemidactylus flaviviridis Ruppell 1835
No full textHemidactylus flaviviridis Rüppell, 1835 Hemidactylus flaviviridis Rüppell, 1835: 18, tav. 6 fig. 2 —Locus typicus: “ Insel Massaua und die benachbarte Küstenlandschaft” (Island of Massawa and the adjacent coastal area). Hemidactylus homoeolepis [partim].— Peters 1882 b: 43. Hemidactylus flaviviridis.— Boulenger, 1903: 82. Hemidactylus flaviviridis.— Showler, 1996: 185. This introduced species on Socotra Island is only known from Hadiboh town and outskirts. We unsuccessfully searched for this species in many other villages (e.g. Qalansiyah). Habitat. We observed it at night time on few buildings in Hadiboh town. It seems always strictly associated to buildings, usually near light spots; the species was also observed inside buildings at daytime. Original data. Fig. 7. Hadiboh plain. Bibliographic data. Blanford (1881 a), Loveridge (1947), Rösler & Wranik (1998, 2003, 2004), Wranik 1998 b. General distribution. A widespread species distributed across most of India, Nepal, Pakistan and eastern Afghanistan. The species has been found in scattered localities on the coasts of Iran, Arabia, Socotra and along the Red Sea coasts of Egypt, Sudan, Eritrea, Djibouti and northern Somalia (cf. the map by Sindaco & Jeremčenko, 2008: 301). In the western part of its range, as well as in Socotra, it was probably unintentionally introduced by man.Published as part of Razzetti, Edoardo, Sindaco, Roberto, Grieco, Cristina, Pella, Francesca, Ziliani, Ugo, Pupin, Fabio, Riservato, Elisa, Pellitteri-Rosa, Daniele, Butikofer, Luca, Suleiman, Ahmed Saeed & Al-Aseily, Badar Awadh, 2011, Annotated checklist and distribution of the Socotran Archipelago Herpetofauna (Reptilia), pp. 1-44 in Zootaxa 2826 on pages 6-7, DOI: 10.5281/zenodo.27727
Typhlops socotranus Boulenger 1889
No full textTyphlops socotranus Boulenger, 1889 Typhlops socotranus Boulenger, 1889: 362 —Locus typicus: “ Socotra ”. Typhlops sp.— Günther 1881: 462. Typhlops socotranus.— Boulenger, 1893: 21, Pl. 2.2[a]–c. This species is known from only few specimens: Steindachner (1903) reports it from Aqarhi [Hakari] in the southern plain (Noged), and an area North of Ras Shu’ab; Boulenger (1889) cites a specimen from Dahamis [in the Hadibu Plain]; Rösler & Wranik (2004) observed two additional individuals from Hasaant (South of Hajhir). Habitat. We collected this species in stony highlands with Croton bushes, sparse shrubs with scattered stones, humid forest with deep soil, between 290 and 550 m a.s.l. Original data. Fig. 30. Ma'alah plateau, Wadi Ayhaft, Rokeb area. Bibliographic data. Boulenger (1889, 1893), Steindachner (1903), Parker (1949), Schätti & Desvoignes (1999), Rösler & Wranik (2004). General distribution. Endemic to Socotra Island. Remarks. Rösler & Wranik (2004) report that the species “ inhabits areas with little moisture and vegetation ”, our observation agree with them, as we also found two individuals in a very humid forested area at Wadi Ayhaft (290 m a.s.l.).Published as part of Razzetti, Edoardo, Sindaco, Roberto, Grieco, Cristina, Pella, Francesca, Ziliani, Ugo, Pupin, Fabio, Riservato, Elisa, Pellitteri-Rosa, Daniele, Butikofer, Luca, Suleiman, Ahmed Saeed & Al-Aseily, Badar Awadh, 2011, Annotated checklist and distribution of the Socotran Archipelago Herpetofauna (Reptilia), pp. 1-44 in Zootaxa 2826 on pages 17-18, DOI: 10.5281/zenodo.27727
Pachycalamus brevis Gunther 1881
No full textPachycalamus brevis Günther, 1881 Pachycalamus brevis Günther, 1881: 462 —Locus typicus: “ Socotra ”. Pachycalamus brevis.— Peters, 1882 a: 583. Pachycalamus brevis.— Gans, 1960: 178. Pachealamus [sic] brevis.— Doe, 1992: 131. Pachycalamus brevis.— Hallermann, 1998: 201. Pachycalamus brevis.— Kearney, 2003: 13 (fig. 8). Pachycalamus brevis.— Gans, 2005: 43. A burrowing species, rarely detected because of its mainly fossorial habits. Habitat. It can be observed under stones or beneath rotten vegetation in habitats with rather deep soils (forested valleys, palm grooves along wadis, bushlands). It was reported also among droppings of goats (Schätti & Desvoignes 1999). We have collected it from 20 m of altitude at Wadi Qishn to 380 m south of Rokeb, but the species was collected at Diksam (695 m) by H. Rösler (Rösler & Wranik, 2004) and Schätti & Desvoignes (1999) cited it from Homhil at 700 m. Original data. Fig. 26. Go'o area, Qeysoh, Wadi Ayhaft, Hadiboh plain, Di Lishah area, Rokeb area. Bibliographic data. Boulenger (1903), Steindachner (1903), Loveridge (1941), Gans (1960), Schätti & Gasperetti (1994), Wranik (1998 b), Schätti & Desvoignes (1999), Rösler & Wranik (2004). General distribution. Endemic to Socotra Island. Remarks. Our record from Qeysoh palm grove is the first from the western part of the island.Published as part of Razzetti, Edoardo, Sindaco, Roberto, Grieco, Cristina, Pella, Francesca, Ziliani, Ugo, Pupin, Fabio, Riservato, Elisa, Pellitteri-Rosa, Daniele, Butikofer, Luca, Suleiman, Ahmed Saeed & Al-Aseily, Badar Awadh, 2011, Annotated checklist and distribution of the Socotran Archipelago Herpetofauna (Reptilia), pp. 1-44 in Zootaxa 2826 on pages 15-16, DOI: 10.5281/zenodo.27727
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