996 resultados para 323-U1339B


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Studies on the flora and fauna of the Canary Islands show that this Archipelago is one of the planet’s diversity hot spots. However, an analysis of the differences in the phytogeographic characteristics of each of the islands that make up this Archipelago is lacking. This article focuses on the phytogeographic characterization of the island of Gran Canaria. This island exhibits geological and climatic characteristics resulting in a rich vascular flora, including endemic species and genera that are significantly different from the other islands of the Archipelago. These differences are verified through statistical analysis of the existing similarity between the floras of the members of the Canary Islands. This study also analyses the subdivision of Gran Canaria Island, indicating that there are three well-differentiated areas on the island itself. Finally, this study argues that these areas, themselves, should be considered biogeographic sectors.

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Fourty-two high-rank syntaxa and seven associations of the thallophyte system of syntaxa are either described as new or validated in this paper. Among those, there are the following nine classes: Aspicilietea candidae, Caulerpetea racemosae, Desmococcetea olivacei, Entophysalidetea deustae, Gloeocapsetea sanguineae, Mesotaenietea berggrenii, Naviculetea gregariae, Porpidietea zeoroidis, Roccelletea phycopsis. Eleven orders and ten alliances as well as three associations are described or validated: the Aspicilietalia verruculosae (incl. Aspicilion mashiginensis and Teloschistion contortuplicati), the Caulerpetalia racemosae (incl. Caulerpion racemosae), the Desmococcetalia olivacei (incl. Desmococcion olivacei), the Dirinetalia massiliensis, the Fucetalia vesiculosi (incl. Ascophyllion nodosi), the Gloeocapsetalia sanguineae, the Lecideetalia confluescentis (incl. Lecideion confluescentis), the Mesotaenietalia berggrenii (incl. Mesotaenion berggrenii, Mesotaenietum berggrenii and Chloromonadetum nivalis), the Naviculetalia gregariae (incl. Oscillatorion limosae and Oscillatorietum limosae), the Porpidietalia zeoroidis (incl. Porpidion zeoroidis), and the Roccelletalia fuciformis (incl. Paralecanographion grumulosae). Further, five orders, seven alliances and four associations, classified in known classes, were described as well. These include: the Bacidinetalia phacodis, the Agonimion octosporae and the Dendrographetalia decolorantis (all in the Arthonio radiatae-Lecidelletea elaeochromae), the Staurothelion solventis (in the Aspicilietea lacustris), the Pediastro duplicis-Scenedesmion quadricaudae and the Pediastro duplicis-Scenedesmetum quadricaudae (both in the Asterionelletea formosae), the Peccanion coralloidis and the Peltuletalia euplocae (both in the Collematetea cristati), the Laminarion hyperboreae, the Saccorhizo polyschidi-Laminarietum and the Alario esculenti-Himanthalietum elongatae (all in the Cystoseiretea crinitae), the Delesserietalia sanguinei, the Delesserion sanguinei and the Delesserietum sanguineae (all in the Lithophylletea soluti), as well as the the Rinodino confragosae-Rusavskietalia elegantis and the Rhizocarpo geographici-Rusavskion elegantis (both in the Rhizocarpetea geographici).

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El uso de agroquímicos en Argentina se ha fortalecido junto con la expansión agrícola. El objetivo de este trabajo es la elaboración de una metodología para calcular el impacto ambiental que los pesticidas causan en el medio ambiente teniendo en cuenta los siguientes factores: "ecotoxicología": categoría toxicológica, toxicidad en abejas, aves y peces; "Toxicidad humana": carcinogenicidad, neurotoxicidad, alteraciones endocrinas, genotoxicidad y capacidad irritativa; "Comportamiento ambiental": la persistencia en el agua / sedimento, persistencia en el suelo y bioconcentración. Estos factores fueron clasificados como bajo, medio, alto o muy alto, de acuerdo con su nivel de toxicidad. Los resultados indican que los plaguicidas más tóxicos son los insecticidas. La mayoría de los pesticidas utilizados son la toxicidad media (43,75%), seguido de baja y alta toxicidad (21,88%) y, los de muy alta toxicidad (12,5%). La metodología propuesta podría ser utilizada como una herramienta de monitoreo, gestión o educación ambiental.

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This article aims to propose a chronological subdivision in the history of African communication. African communication today is one of the most important axes for implementing development strategies, sustaining education, health, and schooling programmes, and so on. However, many of these programmes fail due to a lack of or ineffective communication between international organisations, local elite and lay people. The reasons for this situation must be found in Africa’s history of communication, which has undergone radical transformations in its different phases. Using the functionalist analysis drawn up by Jakobson, this article proposes a new chronological subdivision of Africa’s history of communication, reflecting on the current contradictions in contemporary communication in Africa.

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Objective: To explore general practitioners' perceptions of the effects of their profession and training on their attitudes to illness in themselves and colleagues. Design: Qualitative study using focus groups and indepth interviews. Setting: Primary care in Northern Ireland. Participants: 27 general practitioners, including six recently appointed principals and six who also practised occupational medicine part time. Main outcome measures: Participants' views about their own and colleagues' health. Results: Participants were concerned about the current level of illness within the profession. They described their need to portray a healthy image to both patients and colleagues. This hindered acknowledgement of personal illness and engaging in health screening. Embarrassment in adopting the role of a patient and concerns about confidentiality also influenced their reactions to personal illness. Doctors' attitudes can impede their access to appropriate health care for themselves, their families, and their colleagues. A sense of conscience towards patients and colleagues and the working arrangements of the practice were cited as reasons for working through illness and expecting colleagues to do likewise. Conclusions: General practitioners perceive that their professional position and training adversely influence their attitudes to illness in themselves and their colleagues. Organisational changes within general practice, including revalidation, must take account of barriers experienced by general practitioners in accessing health care. Medical education and culture should strive to promote appropriate self care among doctors.

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We study the ionization of helium (fie) in collision with antiprotons (p) in the energy range from 10 keV to 1000 keV. We adopt a semiclassical single center close coupling approach in which the wave function for the electron is expanded in a B-spline basis centered on the nucleus of the He atom, The calculations are performed using two different models: the independent particle (IP) model and the one-electron (OE) approximation. The interaction between the active electron and the rest of the atom, i.e. passive electron and nucleus, is represented by a model potential. The results obtained are compared with experimental data as well as with existing theoretical calculations. (c) 2005 Published by Elsevier B.V.

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High time resolution observations of a white-light flare on the active star EQ PegB show evidence of intensity variations with a period of ≈10 s. The period drifts to longer values during the decay phase of the flare. If the oscillation is interpreted as an impulsively-excited, standing-acoustic wave in a flare loop, the period implies a loop length of ≈3.4 Mm and ≈6.8 Mm for the case of the fundamental mode and the second harmonic, respectively. However, the small loop lengths imply a very high modulation depth making the acoustic interpretation unlikely. A more realistic interpretation may be that of a fast-MHD wave, with the modulation of the emission being due to the magnetic field. Alternatively, the variations could be due to a series of reconnection events. The periodic signature may then arise as a result of the lateral separation of individual flare loops or current sheets with oscillatory dynamics (i.e., periodic reconnection).

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We present intermediate-resolution HST/STIS spectra of a high- velocity interstellar cloud ((LSR)-L-upsilon = + 80 kms(-1)) towards DI1388, a young star in the Magellanic Bridge located between the Small and Large Magellanic Clouds. The STIS data have a signal-to-noise ratio (S/N) of 20-45 and a spectral resolution of about 6.5 km s(-1) (FWHM), The high-velocity cloud absorption is observed in the lines of C II, O I, Si II, Si III, Si IV and S III. Limits can be placed on the amount of S II and Fe II absorption that is present. An analysis of the relative abundances derived from the observed species, particularly C II and O I, suggests that this high-velocity gas is warm (T-k similar to 10(3)-10(4) K) and predominantly ionized, This hypothesis is supported by the presence of absorption produced by highly ionized species, such as Si IV, This sightline also intercepts two other high-velocity clouds that produce weak absorption features at (LSR)-L-upsilon = + 113 and + 130kms(-1) in the STIS spectra.

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The purpose of this article is to develop a methodological framework for analyzing Policy Coherence for Development (PCD). With this goal, we analyze different views of PCD in order to establish a comprehensive approach of Coherence adapted to globalization process. In this context, the article proposes a methodological framework based on four dimensions of analysis in CPD. In each dimen-sion, we set the areas and actors to investigate and we put forward research questions that could be use as a guide for a comprehensive approach to study PCD.