996 resultados para OCE– (CE–) Regular Spaces


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I. The report describes the main monthly changes in the distribution and abundance of the zooplankton, other than Copepoda and young fish (dealt with in separate reports), over the southern part of the North Sea from 1932 to 1937. The work is part of the survey carried out by Continuous Plankton Recorders towed at a depth of 10 metres on regular steamship lines between England and the Continent. 2. The limitations to the sampling method are discussed, and it is shown to be unsuitable for recording Mysidacea and Euphausiacea on account of their marked diurnal variation due presumably to vertical migration; they are omitted from the report. 3. The changing distribution of Sagitta, Limacina, Clione, Lamellibranch larvae, Cladocera, Caprellid Amphipoda, Decapod larvae, Echinoderm larvae and Oikopleura are shown in a series of monthly charts while their seasonal fluctuations are compared in time-chart histograms. 4. The Alima larvae of Squilla are recorded on a few occasions in the regions where the Channel opens into the North Sea. 5. The distributional characteristics of the different forms, i.e. their tendencies to even or " patchy " production, are compared.

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In 2012, the Western English Channel experienced an unusually large and long-lived phytoplankton spring bloom. When compared with data from the past 20 years, average phytoplankton biomass at Station L4 (part of the Western Channel Observatory) was approximately 3× greater and lasted 50% longer than any previous year. Regular (mostly weekly) box core samples were collected from this site before, during and after the bloom to determine its impact on macrofaunal abundance, diversity, biomass, community structure and function. The spring bloom of 2012 was shown to support a large and rapid response in the majority of benthic taxa and functional groups. However, key differences in the precise nature of this response, as well as in its timing, was observed between different macrofauna feeding groups. Deposit feeders responded almost instantly at the start of the bloom, primarily thorough an increase in abundance. Suspension feeders and opportunistic/predatory/carnivorous taxa responded slightly more slowly and primarily with an increase in biomass. At the end of the bloom a rapid decline in macrobenthic abundance, diversity and biomass closely followed the decline in phytoplankton biomass. With suspension feeders showing evidence of this decline a few weeks before deposit feeders, it was concluded that this collapse in benthic communities was driven primarily by food availability and competition. However, it is possible that environmental hypoxia and the presence of toxic benthic cyanobacteria could also have contributed to this decline. This study shows evidence for strong benthic–pelagic coupling at L4; a shallow (50 m), coastal, fine-sand habitat. It also demonstrates that in such habitats, it is not just planktonic organisms that demonstrate clear community phenology. Different functional groups within the benthic assemblage will respond to the spring bloom in specific manner, with implications for key ecosystem functions and processes, such as secondary production and bioturbation. Only by taking integrated benthic and pelagic observations over such fine temporal scales (weekly) was the current study able to identify the intimate structure of the benthic response. Similar studies from other habitats and under different bloom conditions are urgently needed to fully appreciate the strength of benthic–pelagic coupling in shallow coastal environments.

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Après une analyse de l'Agropyretum mediterraneum l'auteur montre qu'à la lumière dees conceptions actuelles de la Phytosociologique et sur la base des nombreuses données récemment récoltées sur le litoral méditerranéen, cette association historique correspond en fait à un groupe.

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Measures of prevention and control against polycyclic aromatic hydrocarbons (PAHs) focus on an official food control, a code of best practice to reduce PAHs levels by controlling industry and in the development of a chemopreventive strategy. Regulation (EU) 835/2011 establishes maximum levels of PAHs for each food group. In addition, Regulations (EU) 333/2007 and 836/2011 set up the methods of sampling and analysis for its official control. Scientific studies prove that the chemopreventive strategy is effective against these genotoxic compounds effects. Most chemopreventive compounds studied with proven protective effects against PAHs are found in fruit and vegetables.

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This paper describes a study of digital literacy where the researcher worked with one group of English language arts teacher candidates and one of adolescents, reading and writing hypertext fiction. The findings suggest that the adolescent readers/writers brought a more flexible and multiliterate approach to their digital literacy processes than the teacher candidates.

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In the early to mid-twentieth century, many novelists in the Arab world championed Arab nationalism in their literary reflections on the social and political struggles of their countries, depicting these struggles primarily in terms of spatial binaries that pitted the Arab world against the West, even as they imported Western literary models of progress and modernity into their own work. The intense experience of national awakening that infused their writing often placed these authors at a literary disadvantage, for in their literature, all too often the depth and diversity of Arabic cultures and the complexity of socio-political struggles across the Arab world were undermined by restrictive spatial discourses that tended to focus only on particular versions of Arab history and on a seemingly unifying national predicament. Between the Arab defeat of 1967 and the present day, however, an increasing number of Arab authors have turned to less restrictive forms of spatial discourse in search of a language that might offer alternative narratives of hope beyond the predictable, and seemingly thwarted, trajectories of nationalism. This study traces the ways in which contemporary Arab authors from Egypt and the Sudan have endeavoured to re-think and re-define the Arab identity in ever-changing spaces where elements of the local and the global, the traditional and the modern, interact both competitively and harmoniously. I examine the spatial language and the tropes used in three Arabic novels, viewing them through the lens of thawra (revolution) in both its socio-political and artistic manifestations. Linking the manifestations of thawra in each text to different scenes of revolution in the Arab world today, in Chapter Two, I consider how, at a stage when the Sudan of the sixties was both still dealing with colonial withdrawal and struggling to establish itself as a nation-state, the geographical and textual landscapes of Tayeb Salih‟s Season of Migration to the North depict the ongoing dilemma of the Sudanese identity. In Chapter Three, I examine Alaa iii al-Aswany‟s The Yacoubian Building in the context of a socially diseased and politically corrupt Egypt of the nineties: social, political, modern, historical, local, and global elements intertwine in a dizzyingly complex spatial network of associations that sheds light on the complicated reasons behind today‟s Egyptian thawra. In Chapter Four, the final chapter, Gamal al-Ghitani‟s approach to his Egypt in Pyramid Texts drifts far away from Salih‟s anguished Sudan and al-Aswany‟s chaotic Cairo to a realm where thawra manifests itself artistically in a sophisticated spatial language that challenges all forms of spatial hegemony and, consequently, old and new forms of social, political, and cultural oppression in the Arab world.