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Other Continents (other + continent)
Selected AbstractsWeather-based prediction of anthracnose severity using artificial neural network modelsPLANT PATHOLOGY, Issue 4 2004S. Chakraborty Data were collected and analysed from seven field sites in Australia, Brazil and Colombia on weather conditions and the severity of anthracnose disease of the tropical pasture legume Stylosanthes scabra caused by Colletotrichum gloeosporioides. Disease severity and weather data were analysed using artificial neural network (ANN) models developed using data from some or all field sites in Australia and/or South America to predict severity at other sites. Three series of models were developed using different weather summaries. Of these, ANN models with weather for the day of disease assessment and the previous 24 h period had the highest prediction success, and models trained on data from all sites within one continent correctly predicted disease severity in the other continent on more than 75% of days; the overall prediction error was 21·9% for the Australian and 22·1% for the South American model. Of the six cross-continent ANN models trained on pooled data for five sites from two continents to predict severity for the remaining sixth site, the model developed without data from Planaltina in Brazil was the most accurate, with >85% prediction success, and the model without Carimagua in Colombia was the least accurate, with only 54% success. In common with multiple regression models, moisture-related variables such as rain, leaf surface wetness and variables that influence moisture availability such as radiation and wind on the day of disease severity assessment or the day before assessment were the most important weather variables in all ANN models. A set of weights from the ANN models was used to calculate the overall risk of anthracnose for the various sites. Sites with high and low anthracnose risk are present in both continents, and weather conditions at centres of diversity in Brazil and Colombia do not appear to be more conducive than conditions in Australia to serious anthracnose development. [source] Soils of a Mediterranean hot spot of biodiversity and endemism (Sardinia, Tyrrhenian Islands) are inhabited by pan-European, invasive species of Hypocrea/TrichodermaENVIRONMENTAL MICROBIOLOGY, Issue 1 2009Quirico Migheli Summary We have used a Mediterranean hot spot of biodiversity (the Island of Sardinia) to investigate the impact of abiotic factors on the distribution of species of the common soil fungus Trichoderma. To this end, we isolated 482 strains of Hypocrea/Trichoderma from 15 soils comprising undisturbed and disturbed environments (forest, shrub lands and undisturbed or extensively grazed grass steppes respectively). Isolates were identified at the species level by the oligonucleotide BarCode for Hypocrea/Trichoderma (TrichOKEY), sequence similarity analysis (Trichoblast) and phylogenetic inferences. The majority of the isolates were positively identified as pan-European and/or pan-global Hypocrea/Trichoderma species from sections Trichoderma and Pachybasium, comprising H. lixii/T. harzianum, T. gamsii, T. spirale, T. velutinum, T. hamatum, H. koningii/T. koningii, H. virens/T. virens, T. tomentosum, H. semiorbis, H. viridescens/T. viridescens, H. atroviridis/T. atroviride, T. asperellum, H. koningiopsis/T. koningiopsis and Trichoderma sp. Vd2. Only one isolate represented a new, undescribed species belonging to the Harzianum,Catoptron Clade. Internal transcribed spacer sequence analysis revealed only one potentially endemic internal transcribed spacer 1 allele of T. hamatum. All other species exhibited genotypes that were already found in Eurasia or in other continents. Only few cases of correlation of species occurrence with abiotic factors were recorded. The data suggest a strong reduction of native Hypocrea/Trichoderma diversity, which was replaced by extensive invasion of species from Eurasia, Africa and the Pacific Basin. [source] Political Communication in a European Public Space: Language, the Internet and Understanding as Soft Power,JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 2 2008RICHARD ROSE This article demonstrates that the European Union's linguistic diversity policy is a barrier to greater popular participation in a European public space. It sets out three political communication models: elite discourse, aggregative democracy and deliberation in a European public space; each has different linguistic requirements. It presents survey evidence showing that Europeans are ,voting with their mouths' for a single lingua franca, resulting in English as a foreign language (EFL) becoming the most widely understood language in the EU and its use on the internet for transnational as well as domestic communication. More than one-third of Europeans now have the basic prerequisites for participation in a European public space: they are internet users and know the lingua franca of Europe, EFL. The EU's linguistic diversity policy is even more a barrier for participation in a global public space in which EFL is now the lingua franca of Asia and other continents. It concludes that knowledge of EFL does not confer soft power on Anglophones but on Europeans using it in interactions with monoglot American and English speakers. [source] Body size, biomic specialization and range size of African large mammalsJOURNAL OF BIOGEOGRAPHY, Issue 7 2005Manuel Hernández Fernández Abstract Aim, The goal of this paper is to examine the relationships between body size, biomic specialization and range size in the African large mammals, which are defined as all the African species corresponding to the orders Primates, Carnivora, Proboscidea, Perissodactyla, Hyracoidea, Tubulidentata, Artiodactyla and Pholidota. Location, The study used the large mammal assemblage from Africa. Methods, The degree of biomic specialization of African large mammals is investigated using the biomic specialization index (BSI) for each mammal species, based on the number of biomes it inhabits. Range size for each species is measured as the latitudinal extent of the geographical distribution of the species. We have analysed our data using both conventional cross-species analyses and phylogenetically independent contrasts. Results, There is a polygonal relationship between species biomic specialization and body size. While small and large species are biomic specialists, medium-sized species are distributed along the whole range of biomic specialization. The latitudinal extent,body size relationship is approximately triangular. Small-bodied species may have either large or small ranges, whereas large-bodied ones have only large ranges. A positive correlation between latitudinal extent and biomic specialization is evident, although their relationship is better described as triangular. Main conclusions, We found a polygonal relationship between species biomic specialization and body size, which agrees with previous arguments that small-bodied species have more limited dispersal and, therefore, they may come to occupy a lesser proportion of their potential inhabitable biomes. On the other hand, large-bodied species are constrained to inhabit biomes with a high productivity. A polygonal relationship between species latitudinal extent and body size in African large mammals agrees with previous studies of the relationship between range size and body size in other continents. The independent study of the macroecological pattern in biomic specialization highlights different factors that influence the body size,range size relationship. Although body size is usually implicated as a correlate of both specialization and geographical range size in large mammals, much of the variation in these variables cannot be attributed to size differences but to biome specific factors such as productivity, area, history, etc. [source] Desert vines: a comparison of Australia with other areasJOURNAL OF BIOGEOGRAPHY, Issue 1 2005R. F. Parsons Abstract Aim, To characterize the Australian desert vine flora and to compare it with that of deserts in other continents. Location, The Stony Deserts, the Simpson Desert and the four main deserts of Western Australia. Methods, The Western Australian Herbarium data base and published papers were used to develop vine checklists for each Australian desert studied. A literature search was used to classify the families and genera into phytogeographical elements and to provide data for intercontinental comparisons. Results, Thirty-seven vine species are listed for the six Australian deserts studied. They constitute from 0.8 to 2.7% of the vascular flora, which is within the normal range for arid zone floras. Comparing Australian data with those from the Sonoran and Chihuahuan deserts (North America), for non-vine taxa, very different phylogenetic lines are present. However, for vines, three of the four most important families are the same in each case, viz. Convolvulaceae, Fabaceae and Asclepiadaceae. This reflects large pantropical and cosmopolitan families shared between all three data sets. At the generic level, in Australia pantropical taxa and taxa from the Old World tropics far outnumber endemic ones, as do pantropical and neotropical genera in North America. Herbaceous vines predominate in Australian deserts as they do in North American ones, but nevertheless, the percentage of woody vines is higher in Australia (32%) than in North America (highest value of 24%). Earlier views that Australian deserts are rich in annual vines are not supported. Main conclusions, For many life-forms, the Australian flora is composed of very different phylogenetic lines to the floras of other continents. However, for desert vines, at the level of family and even of genus, there are surprising similarities between Australia and even a continent as distant as North America, because of shared pantropical and cosmopolitan taxa. [source] Air pollution: A half century of progressAICHE JOURNAL, Issue 6 2004John H. Seinfeld Abstract In the 50 years since the air pollution episodes of Donora, PA and London, U.K., a great deal of progress has been made in understanding the nature and sources of air pollution and the atmospheric transport and transformation of pollutants. Also, many significant technological advances in air pollution control equipment, such as the automobile exhaust gas catalytic converter, have led to effective reduction of emissions from a variety of major pollution sources. Finally, remarkable developments in instrumentation for sampling the trace species in the atmosphere have been and continue to be made. Relatively less progress has been made in understanding the biological mechanisms by which pollutants lead to human injury and mortality. In this review the focus is on the extraordinary progress that has been made over the last half century in understanding the atmospheric nature and behavior of pollutants, both gaseous and particulate. A major breakthrough was the determination of the gas-phase chemistry of both the natural and polluted atmosphere, chemistry that leads to the formation of ozone and a vast array of oxidized molecules. The mechanisms of the oxidation of atmospheric sulfur dioxide, one of the main primary pollutants, were elucidated. Finally, the chemistry, physics, and optics of atmospheric particulate matter (aerosols) have been laid open by many stunning research achievements. Whereas 50 years ago air pollution was thought to be confined to the area around a city, it is now recognized that species emitted on one continent frequently find their way to other continents. Strategies for dealing with a truly global atmospheric backyard now represent a major challenge. © 2004 American Institute of Chemical Engineers AIChE J, 50:1096,1108, 2004 [source] Review of plant biogeographic studies in BrazilJOURNAL OF SYSTEMATICS EVOLUTION, Issue 5 2009Pedro FIASCHI Abstract, Molecular phylogenetic studies have become a major area of interest in plant systematics, and their impacts on historical biogeographic hypotheses are not to be disregarded. In Brazil, most historical biogeographic studies have relied on animal phylogenies, whereas plant biogeographic studies have largely lacked a phylogenetic component, having a limited utility for historical biogeography. That country, however, is of great importance for most biogeographic studies of lowland tropical South America, and it includes areas from a number of biogeographic regions of the continent. Important biogeographic reports have been published as part of phylogenetic studies, taxonomic monographs, and regional accounts for small areas or phytogeographic domains, but the available information is subsequently scattered and sometimes hard to find. In this paper we review some relevant angiosperm biogeographic studies in Brazil. Initially we briefly discuss the importance of other continents as source areas for the South American flora. Then we present a subdivision of Brazil into phytogeographic domains, and we cite studies that have explored the detection of biogeographic units (areas of endemism) and how they are historically related among those domains. Examples of plant taxa that could be used to test some biogeographic hypotheses are provided throughout, as well as taxa that exemplify several patterns of endemism and disjunction in the Brazilian angiosperm flora. [source] Craniomandibular joint in South American burrowing rodents (Ctenomyidae): adaptations and constraints related to a specialized mandibular position in diggingJOURNAL OF ZOOLOGY, Issue 3 2006D. H. Verzi Abstract A quali-quantitative morphofunctional analysis of the craniomandibular joint in subterranean rodents of the family Ctenomyidae showed that specializations of this joint are coupled with adaptations to digging. The presence of a postglenoid articular region in the skull of Eucelophorus and Ctenomys implies a new position of the mandible in digging, different from those involved in gnawing and chewing. In this third position of the mandible, the mandibular joint is stabilized when the deeply inserted incisors attack the soil or an obstacle, preventing dislocation. The proposed new mandibular function imposes a mechanical constraint on size and shape of the auditory bullae in tooth-digger ctenomyids, because inflated bullae preclude a satisfactory opening of the mandible when it articulates in the postglenoid region. The configuration of the craniomandibular joint and other specializations for digging of Eucelophorus are unique among all South American rodents. The presence of non-homologous, and even more specialized, postglenoid cavities in burrowing rodents of other continents suggests a common requirement for stabilizing the mandibular joint when strong forces with incisors are developed. The less specialized postglenoid region of Eucelophorus and Ctenomys, with respect to that of other rodent clades, may be related to the more recent differentiation of ctenomyids. [source] Body size and extinction risk in Australian mammals: An information-theoretic approachAUSTRAL ECOLOGY, Issue 6 2010RYAN A. CHISHOLM Abstract The critical weight range (CWR) hypothesis for Australian mammals states that extinctions and declines have been concentrated in species with body mass between 35 g and 5.5 kg. The biological basis for this hypothesis is that species of intermediate size are disproportionately impacted by introduced predators. The CWR hypothesis has received support from several statistical studies over the past decade, although the evidence is weaker or non-existent for certain groups such as mesic-zone mammals and arboreal mammals. In this study, we employ an information-theoretic model selection approach to gain further insights into the relationship between body mass and extinction risk in Australian mammals. We find evidence, consistent with the CWR hypothesis, that extinction risk peaks at intermediate body masses for marsupials, rodents and ground-dwelling species, but not for arboreal species. In contrast to previous studies, we find that the CWR describes extinction patterns in the mesic zone as well as the arid zone. In the mesic zone, there is also a weaker tendency for large species above the CWR to be more vulnerable, consistent with extinction patterns on other continents. We find that a more biological plausible Gaussian distribution consistently fits the data better than the polynomial models that have been used in previous studies. Our results justify conservation programmes targeted at species within the CWR across Australia. [source] Evaluating the role of the dingo as a trophic regulator in Australian ecosystemsAUSTRAL ECOLOGY, Issue 5 2007A. S. GLEN Abstract The importance of strongly interactive predators has been demonstrated in many ecosystems, and the maintenance or restoration of species interactions is a major priority in the global conservation of biodiversity. By limiting populations of prey and/or competitors, apex predators can increase the diversity of systems, often exerting influences that cascade through several trophic levels. In Australia, emerging evidence points increasingly towards the dingo (Canis lupus dingo) as a strongly interactive species that has profound effects on ecosystem function. Through predatory and competitive effects, dingoes can alter the abundance and function of mesopredators including the introduced red fox (Vulpes vulpes) and feral cat (Felis catus), and herbivores including the European rabbit (Oryctolagus cuniculus). These effects often benefit populations of native prey, and diversity and biomass of vegetation, but may not occur under all circumstances. For example, the social structure of dingoes is of great importance; a pack subject to minimal human interference regulates its own numbers, and such packs appear to have fewer undesirable impacts such as predation on livestock. Despite abundant observational evidence that the dingo is a strong interactor, there have been few attempts to test its ecological role experimentally. Given the well-recognized importance of species interactions to ecosystem function, it is imperative that such experiments be carried out. To do this, we propose three broad questions: (i) do dingoes limit the abundance of other predators or prey? (ii) do dingoes affect the ecological relationships of other predators or prey (e.g. by altering their spatial or temporal activity patterns)? and (iii) does the removal or reintroduction of dingoes entrain ecological cascades? Finally, we discuss the design of appropriate experiments, using principles that may also be applied to investigate species interactions on other continents. Research might seek to clarify not only the impacts of dingoes at all trophic levels, but also the mechanisms by which these impacts occur. [source] Factors affecting the occupation of a colony site in Sydney., New South Wales by the Grey-headed Flying-fox Pteropus poliocephalus (Pteropodidae)AUSTRAL ECOLOGY, Issue 1 2001K. A. PARRY-JONES Abstract Previous authors have reported that Pteropus poliocephalus colony sites are occupied in response to blossom availability. However, in the present study it is reported that at the Gordon site in suburban Sydney, colony numbers were negatively correlated with the occurrence of pollen in the droppings. In addition, in contrast to reported occupational patterns at other colony sites, where flying-foxes are not present at the site during winter and early spring, the Gordon site was occupied by substantial numbers of flying-foxes throughout the entire period of 62 months from 1985 to 1990. As a result of the introduction of plants native to other parts of Australia and exotics from other continents, there is a variety of foods available throughout the year in the Sydney region, in comparison with less urbanized areas. This food supply permits the occupation of the Gordon colony site during winter and spring and reduces the migratory behaviour of flying-foxes throughout the year. It is concluded that in the absence of a restrictive food supply, the occupational pattern of the Gordon colony of P. poliocephalus is the result of the reproductive requirements of the species modified by the vagaries of blossom production in the native forests outside the foraging range of the colony. [source] Factors affecting the occupation of a colony site in Sydney, New South Wales by the Grey-headed Flying-fox Pteropus poliocephalus (Pteropodidae)AUSTRAL ECOLOGY, Issue 1 2001K. A. Parry-Jones Abstract Previous authors have reported that Pteropus poliocephalus colony sites are occupied in response to blossom availability. However, in the present study it is reported that at the Gordon site in suburban Sydney, colony numbers were negatively correlated with the occurrence of pollen in the droppings. In addition, in contrast to reported occupational patterns at other colony sites, where flying-foxes are not present at the site during winter and early spring, the Gordon site was occupied by substantial numbers of flying-foxes throughout the entire period of 62 months from 1985 to 1990. As a result of the introduction of plants native to other parts of Australia and exotics from other continents, there is a variety of foods available throughout the year in the Sydney region, in comparison with less urbanized areas. This food supply permits the occupation of the Gordon colony site during winter and spring and reduces the migratory behaviour of flying-foxes throughout the year. It is concluded that in the absence of a restrictive food supply, the occupational pattern of the Gordon colony of P. poliocephalus is the result of the reproductive requirements of the species modified by the vagaries of blossom production in the native forests outside the foraging range of the colony. [source] | |||||||||||||