915 resultados para Coexistence. H Pectoralis. H Sellowi. Maxent. ENFA. Competition. Niche Conservatism
Resumo:
The European desire to ensure that bearers of EU rights are adequately compensated for any infringement of these rights, particularly in cases where the harm is widely diffused, and perhaps not even noticed by those affected by it, collides with another desire: to avoid the perceived excesses of an American-style system of class actions. The excesses of these American class actions are in European discourse presented as a sort of bogeyman, which is a source of irrational fear, often presented by parental or other authority figures. But when looked at critically, the bogeyman disappears. In this paper, I examine the European (and UK) proposals for collective action. I compare them to the American regime. The flaws and purported excesses of the American regime, I argue, are exaggerated. A close, objective examination of the American regime shows this. I conclude that it is not the mythical bogeyman of a US class action that is the barrier to effective collective redress; rather, the barriers to effective, wide-ranging group actions lie within European legal culture and traditions, particularly those mandating individual control over litigation.
Resumo:
While transnational antitrust enforcement is becoming only more common, the access to foreign-based evidence remains a considerable practical challenge. This article appraises considerations and concerns surrounding confidentiality, and looks into ways of their possible accommodation. It further identifies and critically evaluates the existing mechanisms allowing for inter-agency confidential information/ evidence sharing in competition law enforcement. The article outlines the shortcomings of the current framework and points to novel unilateral approaches. In the latter regard the focus is devoted to Australia, where the competition agency is empowered to share confidential information with foreign counterparts, also without any underlying bilateral agreement and on a non-reciprocal basis. This solution shows that a pragmatic and workable approach to inter-agency evidence sharing can be achieved.
Resumo:
1. Patterns of coexistence and exclusion among resident and invading species in freshwaters may be generated by direct biotic interactions well as by indirect interactions with the broader abiotic and biotic environments. The North American ‘shrimp’ Crangonyx pseudogracilis (Crustacea: Amphipoda) is invasive in Europe where it forms complex patterns of apparent exclusion and coexistence with resident Gammarus spp. amphipods. Using a comprehensive integrated approach, we investigated the potential biotic and interacting abiotic factors driving these distribution patterns.
2. A 2009 of 69 sites revealed that of 56 river sites containing amphipods only 6 contained C. pseudogracilis and these always co-occurred with Gammarus spp.. In contrast, C. pseudogracilis was the only species present in the 12 ponds/reservoirs containing amphipods.
3. Field transplant experiments in ponds and laboratory oxygen tolerance experiments revealed that C. pseudogracilis tolerates physicochemical regimes which Gammarus spp. are incapable of surviving.
4. River microhabitat sampling showed C. pseudogracilis dominating in slower, more pooled and macrophyte-dense patches, while Gammarus spp. were dominant in faster, more riffled areas.
5. Field bioassays indicated that predation of C. pseudogracilis by Gammarus spp. may be frequent in patches of rivers if/when the species meet.
6. River drift sampling revealed that C. pseudogracilis was greatly underrepresented in night/day drift relative to the Gammarus spp.. Laboratory studies showed C. pseudogracilis to be more photophobic and less active than Gammarus spp., both behaviours potentially contributing to low drift prevalence and consequent reduced exposure to shared drift predators.
7. These interacting factors may ultimately contribute to the coexistence, exclusion and relative distributions of C. pseudogracilis and Gammarus spp.. The former is potentially subject to intense predation from the latter if they encounter one another in the same microhabitat. However, with C. pseudogracilis being more physicochemically tolerant and displaying different habitat utilisation patterns than the Gammarus spp. in respect of the benthos and drift, such encounters are probably minimised. Hence C. pseudogracilis can persist in the same sites with the Gammarus spp., albeit in different microhabitats.
Resumo:
Understanding and predicting the outcomes of biological invasions is challenging where multiple invader and native species interact. We hypothesize that antagonistic interactions between invaders and natives could divert their impact on subsequent invasive species, thus facilitating coexistence. From field data, we found that, when existing together in freshwater sites, the native amphipod Gammarus duebeni celticus and a previous invader G. pulex appear to facilitate the establishment of a second invader, their shared prey Crangonyx pseudogracilis. Indeed, the latter species was rarely found at sites where each Gammarus species was present on its own. Experiments indicated that this may be the result of G. d. celticus and G. pulex engaging in more intraguild predation (IGP) than cannibalism; when the ‘enemy’ of either Gammarus species was present, that is, the other Gammarus species, C. pseudogracilis significantly more often escaped predation. Thus, the presence of mutual enemies and the stronger inter- than intraspecific interactions they engage in can facilitate other invaders. With some invasive species such as C. pseudogracilis having no known detrimental effects on native species, and indeed having some positive ecological effects, we also conclude that some invasions could promote biodiversity and ecosystem functioning.
Resumo:
This chapter examines the issue of coexistence of genetically modified organisms (GMOs) alongside conventional and organic crops. The central focus is on whether there is a veritable opportunity for coexistence of all three types of crops, which allows for freedom of choice by both farmers and consumers. It commences by considering the nature of the general GM regime, the relationship between the frameworks for cultivation and the use and sale of GM food and feed, and the main elements of the cultivation regime. In light of this, the concept of coexistence is considered, with an evaluation of both the legal and practical elements. Although the general GM regime is controlled at an EU level, coexistence is apparently left to the Member States who may take appropriate coexistence measures. Nonetheless, the Commission has created Recommendations that are to guide the Member States in their choice of measures. To a great extent, what is considered ‘appropriate’ is to be determined by the economic impact upon the farmers and the relationship with the labelling thresholds. The chapter evaluates the future of coexistence, bearing in mind the continued use of the safeguard clauses, the declaration of ‘GM-free’ regions, the potential for national ‘opt-outs’ and the general practical challenges of maintaining coexistence including the ‘domino effect’. Overall, it is arguable that coexistence is a misnomer and that if the term’s meaning is strictly maintained then veritable coexistence that allows for freedom of choice by both farmers and consumers seems unattainable. Although not directly controlled by CAP, there are strong areas of overlap and they share a number of similar objectives; the chapter will conclude by considering whether the approaches in relation to CAP and the cultivation of GMOs are converging or diverging.
Resumo:
We examined the patterns of distribution and abundance, and reproductive traits (presence of gametophytes and size at time of reproduction) in the invasive Codium fragile ssp. fragile and the native C. tomentosum and C. vermilara on intertidal habitats of NW Spain at two dates. All three species coexist in the locations and habitats studied, although abundances were low. We found a greater proportion of C. fragile ssp. fragile towards the east of the Cantabrian coast and on upper levels on the shore, where conditions are more stressful. The proportion of thalli bearing gametangia in C. fragile ssp. fragile was greater than in the native species in all habitats. The presence of gametangia was size-dependent for all species, with the invasive species maturing at a smaller size, which combined with the previous features, might confer competitive advantages to this species over the native species. We also demonstrated that molecular analyses are necessary for the correct identification of C. fragile subspecies.
Resumo:
Discusses the amendments to the Polish Competition Act 2007 adopted in June 2014 which aim to enhance the effectiveness of antitrust enforcement, including the introduction of: (1) civil fines for individuals; (2) a "leniency plus" programme based on the US model; (3) a settlement procedure; and (4) extended inspection powers for the Competition Authority. Assesses the likely effectiveness of the reforms.
Resumo:
There is increasing appreciation that hosts in natural populations are subject to infection by multiple parasite species. Yet the epidemiological and ecological processes determining the outcome of mixed infections are poorly understood. Here, we use two intracellular gut parasites (Microsporidia), one exotic and one co-evolved in the western honeybee (Apis mellifera), in an experiment in which either one or both parasites were administered either simultaneously or sequentially. We provide clear evidence of within-host competition; order of infection was an important determinant of the competitive outcome between parasites, with the first parasite significantly inhibiting the growth of the second, regardless of species. However, the strength of this ‘priority effect’ was highly asymmetric, with the exotic Nosema ceranae exhibiting stronger inhibition of Nosema apis than vice versa. Our results reveal an unusual asymmetry in parasite competition that is dependent on order of infection. When incorporated into a mathematical model of disease prevalence, we find asymmetric competition to be an important predictor of the patterns of parasite prevalence found in nature. Our findings demonstrate the wider significance of complex multi-host–multi-parasite interactions as drivers of host–pathogen community structure
Resumo:
We study the competing effects of simultaneous Markovian and non-Markovian decoherence mechanisms acting on a single spin. We show the existence of a threshold in the relative strength of such mechanisms above which the spin dynamics becomes fully Markovian, as revealed by the use of several non-Markovianity measures. We identify a measure-dependent nested structure of such thresholds, hinting at a causality relationship among the various non-Markovianity witnesses used in our analysis. Our considerations are then used to argue the unavoidably non-Markovian evolution of a single-electron quantum dot exposed to both intrinsic and Markovian technical noise, the latter of arbitrary strength.
Resumo:
Background: Active travel to school can be an important contributor to the total physical activity of children but levels have declined and more novel approaches are required to stimulate this as an habitual behaviour. The aim of this mixed methods study was to investigate the feasibility of an international walk to school competition supported by novel swipecard technology to increase children's walking to/from school. Methods: Children aged 9-13 years old participated in an international walk to school competition to win points for themselves, their school and their country over a 4-week period. Walks to and from school were recorded using swipecard technology and a bespoke website. For each point earned by participants, 1 pence (£0.01) was donated to the charity of the school's choice. The primary outcome was number of walks to/from school objectively recorded using the swipecard tracking system over the intervention period. Other measures included attitudes towards walking collected at baseline and week 4 (post-intervention). A qualitative sub-study involving focus groups with children, parents and teachers provided further insight. Results: A total of 3817 children (mean age 11.5±SD 0.7) from 12 schools in three cities (London and Reading, England and Vancouver, Canada) took part in the intervention, representing a 95% intervention participation rate. Results show a gradual decline in the average number of children walking to and from school over the 4-week period (week 1 mean 29%±SD2.5; week 2 mean 18%±SD3.6; week 3 mean 14%±SD4.0; week 4 mean 12%±SD1.1). Post intervention, 97% of children felt that walking to school helped them stay healthy, feel happy (81%) and stay alert in class (76%). These results are supported by qualitative findings from children, parents and teachers. Key areas for improvement include the need to incorporate strategies for maintenance of behaviour change into the intervention and also to adopt novel methods of data collection to increase follow-up rates. Conclusions: This mixed methods study suggests that an international walk to school competition using innovative technology can be feasibly implemented and offers a novel way of engaging schools and motivating children to walk to school.