343 research outputs found
Monographie du palais de Fontainebleau
No full textFontainebleau, Dungeon (roof detail) Cour Ovale (Plate # 3); Monographie du Palais de Fontainebleau, dessinée Gravée par M. Rodolphe Pfnor, published by Vve. A. Morel et Cie Éditeurs, Paris in 1873, 2 volumes. Source: University of Toronto Libraries; http://main.library.utoronto.ca/ (accessed 2/1/2008
Ressenya de: Christin, Rodolphe (2018). Manual del Anti-turismo. València: Fuera de Ruta
No full textEn paraules del seu autor, autodefinit com “un turista més”, aquest és un llibre dirigit, amb mala intenció, als amants dels viatges i del món. El seu objectiu és analitzar el “drama del turisme”, com ell mateix l’anomena. És el turista un destructor marginal? La pregunta ens trasllada a l’univers on els turistes es converteixen en els principals actius de la “món-fàgia”. Literalment, menjar-se el món. El turisme com a consumidor i principal depredador d’una espècie que resulta el món sencer. Partint del principi de racionalització absoluta introduït per Max Weber a l’era científica i tècnica que significà la industrialització de finals del segle XIX i principis del XX, el sociòleg Rodolphe Christin ens planteja un espai convertit en parc, escenificat i modelitzat per la tecnosfera, on el turista assumeix el paper d’espectador-consumidor, i l’hàbitat el d’actor.In the words of its author, self-described as "another tourist", this is a book intended, with a bad intention, for travel lovers and the world. His goal is to analyze the "tourism drama", as he calls it. Is the tourist a marginal destroyer? The question takes us to the world where tourists become the main assets of the "world-phagia". Literally eating the world. Tourism as the main consumer and predator of a species that is the whole world. Based on the principle of absolute rationalization introduced by Max Weber into the scientific and technical era of industrialization in the late nineteenth and early twentieth centuries, sociologist Rodolphe Christin proposes a park-turned space, staged and modeled by the technosphere, where the tourist assumes the role of spectator-consumer, and the habitat the actor. Book Review. ISBN: 9788494789724.Ressenya de: Christin, Rodolphe (2018). Manual del Anti-turismo. València: Fuera de Rut
Biometric Data and Bone Identification of Topmouth Gudgeon Pseudorasbora Parva and Sunbleak Leucaspius Delineatus
No full textIdentification and analysis of the size and composition of prey taken by piscivorous predators assists in the further understanding of ecology of piscivorous fauna (Mann & Beaumont 1980, Hansel et al. 1988, Copp & Roche 2003). Comprehensive evaluation of the digested prey is central to the assessment of predation impacts and is equally important for sustainable fisheries management. Two non-native fish species in England that may be potential prey for native species are sunbleak Leucaspius delineatus (Heckel) and topmouth gudgeon Pseudorasbora parva (Temminck et Schlegel). These species were introduced to English waters in the mid 1980’s (Farr - Cox 1996, Gozlan et al. 2002) where they have since developed extensive populations (Gozlan et al. 2003, Hickley & Chare 2004). Recent studies associate sunbleak and topmouth gudgeon with novel non-native parasites (Beyer et al. 2005, Gozlan et al. 2005). Results such as these have emphasized the need to be able to identify these two species as part of the native predators’ diet. The aim of the study was to provide a tool for species identification and to elaborate the biometric relationships between bone dimensions and body size of sunbleak and topmouth gudgeon. Head bones of fish are particularly useful for identifying the size and composition of prey species from the food remains of predators, as they withstand digestion and are
taxonomically valuable (Copp & Kováč 2003)
Introduced Pathogens and Native Freshwater Biodiversity: A Case Study of Sphaerothecum destruens
No full textA recent threat to European fish diversity was attributed to the association between an intracellular parasite, Sphaerothecum destruens, and a healthy freshwater fish carrier, the invasive Pseudorasbora parva originating from China. The pathogen was found to be responsible for the decline and local extinction of the European endangered cyprinid Leucaspius delineatus and high mortalities in stocks of Chinook and Atlantic salmon in the USA. Here, we show that the emerging S. destruens is also a threat to a wider range of freshwater fish than originally suspected such as bream, common carp, and roach. This is a true generalist as an analysis of susceptible hosts shows that S. destruens is not limited to a phylogenetically narrow host spectrum. This disease agent is a threat to fish biodiversity as it can amplify within multiple hosts and cause high mortalities
Initial Impact of the Gabíkovo Hydroelectric Scheme on the Species Richness and Composition of 0+ Fish Assemblages in the Slovak Flood Plain, River Danube
No full textRelatively little information exists on the effects of hydroelectric schemes on 0+ fish composition in large European rivers because few or no pre-impact data exist. We compared 0+ fish species richness and composition, relative density, fish size as well as available and used habitat using data from 12 floodplain sites sampled just prior to (1992) and four years after (1996) the start of operations of the Gabíkovo hydropower station on the River Danube (Slovakia). We also used modelling techniques to assess the change in species richness and habitat use and to predict 1996 occurrences from the 1992 data set. The floodplain was greatly modified by the hydroscheme. Only 12 of 27 sites sampled in August 1992 were extant in August 1996. Therefore, all four channel types identified (flowing, abandoned, weir, wing-dam) were more lentic in 1996 than in 1992, with increased width, smaller-sized sediment (silt, clay) and greater amounts of macrophytes. After the operations of the hydroscheme, the overall relative density of fishes (individuals per surface area) of all ages decreased, with the exception of 0+ fishes, despite a slight reduction in 0+ fish density in all channel types except weirs. Species number increased from 25 to 28, although in all channel types there was a change in the composition of the 0+ fish assemblages, with rheophiles generally replaced by limnophiles and migrants from the lower Danube. The two most important microhabitat variables were the proportion of macrophytes and gravel, the latter being the factor distinguishing 0+ fish microhabitat use in 1992 (preferences) and 1996 (indifference or avoidance). Species richness and 0+ fish density in 1996 could be predicted from the 1992 data using simple log-linear models (density, richness, sample number). Species-specific occurrence in 1996 could not be predicted using environmental/fish data from 1992 with multiple regression or generalized additive models (GAM). However, the overall GAM from 1992 could predict overall fish occurrence in 1996
Ecological implications of introducing Leucaspius delineatus (Heckel, 1843) and Pseudorasbora parva (Temminck and Schlegel, 1842) into inland waters in England
No full textNon-native species invasions threaten the structure, function and biodiversity of ecosystems worldwide, and those of non-native fishes pose amongst the greatest threats to inland waters of the U.K. This PhD investigated the establishment, dispersal and ecological implications of introducing the two non-native fish species, sunbleak Leucaspius delineatus (Heckel, 1843) and topmouth gudgeon Pseudorasbora parva (Temminck and Schlegel, 1842) to inland waters of England. The introduction and initial dispersal of both species can be attributed to the commercial fish trade. Species-specific variability of life history, growth and morphological traits was examined in sunbleak (12 sites) and topmouth gudgeon (3 sites) to assess their role in establishment success. The drift dynamics, i.e. timing and intensity (propagule pressure), of sunbleak and topmouth gudgeon were assessed for source populations to determine dispersal potential. Potential risks for native species posed by these two alien cyprinids were assessed with respect to the parasite fauna and overlaps in resource use. For sunbleak, these were also examined in terms of social integration of this species into a native fish assemblage. Biological resistance to topmouth gudgeon invasion was evaluated by stomach flushing and gut content analysis of native piscivorous fishes.Inter-population variability in life histories and morphological characters were observed in both sunbleak and topmouth gudgeon. Populations of both species matured at small body sizes and between the ages 1 and 2. The fish were of good body condition and exhibited high reproductive investment. In both species, dispersal from source waters followed a diel pattern, with higher rates at night than during the day (e.g. maximum drift densities during May of 2004 and 2005: 9-10 sunbleak per 1000 m -3 at about 23:00 hrs; 40-52 topmouth gudgeon per 1000 m -3 at about 05:00 hrs). Downstream of one source population, microhabitat use of topmouth gudgeon was found to overlap with native species (brown trout Salmo trutta L., European chub Leuciscus cephalus (L.), bullhead Cottus gobio L., stoneloach Barbatula barbatula (L.); both brown trout and chub were observed to prey on topmouth gudgeon. However, predation intensity may be density-dependent and of insufficient level to impede topmouth gudgeon establishment, which was facilitated in the receiving stream by the consistent propagule pressure from on-line source populations. Sunbleak diet and microhabitat use also overlapped with native species (roach Rutilus rutilus (L.) and common bream Abramis brama (L.)) as young larvae, but this decreased with age. Social network analysis of sunbleak-native species interactions revealed that sunbleak creates significantly stronger social bonds with the native species than do natives amongst themselves.No macro-parasites were found in topmouth gudgeon, but two ‘Category II’ non-native parasites Neoergasilus japonicus (Harada, 1930) and Ergasilus briani (Markewitsch, 1932) were found in some populations of sunbleak. The potential for sunbleak to spread beyond their current distribution in England and the species’ social integration behaviour may facilitate the dispersal of these parasites, which may spread faster among communities invaded by sunbleak than in those where this non-native species is absent. The results of this PhD study are discussed within their wider context and their relevance to non-native species risk analysis and management
Biogeographie des Maladies Infectieuses Émergentes
No full textLa récente pandémie de Covid19 nous rappelle, si cela était encore nécessaire, que la propagation des maladies infectieuses ignore les frontières géographiques. Les changements combinés de biodiversité locale et l’utilisation des terres, l’augmentation de la connectivité internationale par le transport et le commerce ainsi que la menace imminente du changement climatique a accru le risque d’émergence et de réémergence des maladies infectieuses (EMI). Jusqu’à présent la réponse des politiques de santé publique a été la surveillance passive sans toutefois s’avérer réellement efficace dans la prévention et le contrôle des épidémies. Le choix qui a été fait ici est celui d’une nouvelle approche anticipative, par identification des zones à haut risques d’EMI en se basant sur la détection des facteurs environnementaux les plus favorisant. Parmi ces facteurs on trouve la conversion des terres, la diminution drastique de la biodiversité ou encore le changement climatique. Ainsi la méthode biogéographique a permis d’étudier et d’analyser les EMI à travers différents groupes de taxons de pathogènes comme les bactéries, les virus, les protozoaires et les champignons. L’étude a été portée globalement, ainsi que localement, en Guyane Française, un territoire français d’outre-mer situé en Amérique du Sud. Dans les deux cas, à travers les différents groupes de pathogènes, les risques d’inondation, les récentes conversions de parcelles de forêts en terres agro-minières et l’augmentation du minimum de température due au changement climatique se sont avérés être des facteurs significatifs dans l’émergence globale et locale des maladies infectieuses étudiées. Les principaux résultats de cette thèse sont les suivantes :1. Une approche biogéographique de modélisation de la distribution des EMI en utilisant les bases de données existantes sur les cas cliniques, l’imagerie satellite et un modèle statistique non conventionnel est efficace pour détecter précocement les régions à risque, permettre d’améliorer la prévention, et contrôler leur diffusion.2. Il est possible d’anticiper les EMI en identifiant et en gérant précocement les facteurs favorisant ayant un lien direct avec l’anthropisation de l’environnement.The COVID-19 pandemic highlights that the spread of infectious diseases goes beyond geographical boundaries. Simultaneous changes in local biodiversity and land use, the increasing international connectivity through human transport and trade and the imminent threat of climate change have increased the risk of the emergence and reemergence of infectious diseases. The current public health response to emerging infectious diseases (EID) by passive surveillance has proven largely ineffective in preventing and controlling disease outbreaks. The way toward is to “get ahead of the curve” by identifying potential hotspots of disease emergence and detecting the environmental triggers such as land transformation, biodiversity loss and climate change. I used a biogeographic approach to study and analyze disease emergence across different taxonomic pathogen groups such as bacterial, viral, protozoal and fungal, globally and in French Guiana, a French Overseas territory located in South America. I found that regions at risk of floods, recent conversion of forest to agricultural lands and increasing minimum temperature (i.e. temperature at night) caused by cli mate change were drivers for disease emergence locally and globally across the different pathogen groups. The main findings of the PhD thesis are the following:1. Biogeographic approach to mapping the distribution of EIDs with using existing human cases data, remote sensing imagery and unconventional statistical models is effective to “get ahead of the curve” in the detection of regions at risk and the management of EIDs.2. EIDs are not unprecedented but predictable by identifying and managing the triggers of disease emergence, which have a direct link with the anthropization of the environment
Understanding the threats posed by non-native species: public vs. conservation managers.
No full textPublic perception is a key factor influencing current conservation policy. Therefore, it is important to determine the influence of the public, end-users and scientists on the prioritisation of conservation issues and the direct implications for policy makers. Here, we assessed public attitudes and the perception of conservation managers to five non-native species in the UK, with these supplemented by those of an ecosystem user, freshwater anglers. We found that threat perception was not influenced by the volume of scientific research or by the actual threats posed by the specific non-native species. Media interest also reflected public perception and vice versa. Anglers were most concerned with perceived threats to their recreational activities but their concerns did not correspond to the greatest demonstrated ecological threat. The perception of conservation managers was an amalgamation of public and angler opinions but was mismatched to quantified ecological risks of the species. As this suggests that invasive species management in the UK is vulnerable to a knowledge gap, researchers must consider the intrinsic characteristics of their study species to determine whether raising public perception will be effective. The case study of the topmouth gudgeon Pseudorasbora parva reveals that media pressure and political debate has greater capacity to ignite policy changes and impact studies on non-native species than scientific evidence alone
Social network properties within a fish assemblage invaded by non-native sunbleak Leucaspius delineatus
No full textNetwork theory is commonly applied to identify local and global properties of interconnected nodes, such as brain cells or websites on the internet (Newman, 2003a). Despite its potential to quantify disease spread (Newman, 2002) as well as the social interactions between individuals within and between groups, network theory has rarely been used to examine the social organisation of animal groups ([Lusseau, 2003], [Croft et al., 2004], [Croft et al., 2006] and [Godfrey et al., 2009]). The application of social network analysis to interactions in animal populations has great potential. For example, it may assist in the progress of research and analysis of co-operative behaviour, the transmission of information via social interactions and the mechanisms of disease and/or parasite transmission (Watts and Strogatz, 1998 D.J. Watts and S.H. Strogatz, Collective dynamics of small world networks, Nature 393 (1998), pp. 440–442. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (6835)[Watts and Strogatz, 1998], [Latora and Marchiori, 2001] and [Abramson and Kuperman, 2001]). It is also possible to predict a network's resistance to predation and the subsequent loss of individuals (Lusseau, 2003), as well as to examine social segregation (Newman, 2003b). Indeed, social network analysis may assist in the better understanding of the social integration of invasive species and the characteristics of a successful invasion. It may be particularly useful in uncovering new important social traits used in ecosystem colonisation.
Many organisms form groups with benefits that have traditionally been explained by performance in predator–prey interactions and locomotion efficiency ([Magurran, 1990] and [Pitcher and Parrish, 1993]). But more recently, studies have suggested that abilities that enable social group-living may rather reveal direct information about individual performance that may have evolved as amplifiers of individual quality (Barber and Folstad, 2000). The drivers of social organisation include responses to predation pressure and inter-specific competition that can determine the success or failure of entire populations. For group-living organisms, such as shoaling fishes, social structure may be particularly important following the introduction of a new species, which may compete within the shoal for positions normally occupied by native fishes (Witte et al., 1992).
In most organisms, early life is a crucial phase for growth and subsequent survival to recruitment. During their early life, fishes undergo a series of ontogenetic changes in morphology, behaviour, physiology, ecological interactions and thus in their performance-related capabilities ([Balon, 1975] and [Balon, 1990]). The aim of the present study was to apply the network approach to assess social network properties within a fish assemblage that has been invaded by non-native sunbleak Leucaspius delineatus (Heckel, 1843) during early life. A small cyprinid native to most of continental Europe, the sunbleak was introduced into the Stoneham Lakes (Southern England) in the mid-1980s via the aquaculture trade (Farr-Cox et al., 1996) and has since become well established in various canal systems, rivers and lakes of the South and South West of England. A few populations have also been discovered in the North West of the country ([Gozlan et al., 2003] and [Hickley and Chare, 2004]) and more recently in the Southeastern English counties of East Sussex and Kent (G. Zięba and G.H. Copp, unpubl. data, 2009).
Sunbleak naturally aggregate in shoals throughout their life ([Rüppell and Gößwein, 1972], [Siegmund and Wolff, 1973a], [Siegmund and Wolff, 1973b], [Andoerfer, 1980], [Arnold and Längert, 1995] and [Pinder and Gozlan, 2004]), which suggests strong social connections between individual fish. As a means of identifying one or more mechanisms that may facilitate the invasion process of sunbleak, our objectives were to: (1) determine whether sunbleak integrate into the native species social network during their early life, and (2) assess the properties of the social ties between the invading sunbleak and native species during their early development. This is the first study that utilises network analysis to examine the social properties of a native fish assemblage containing a non-native fish species
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