Spatial and temporal patterns of coral bleaching around Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands

Since 2001, biannual fish and habitat monitoring has been conducted for the shallow (> 30 m), colonized pavement and gorgonian dominated Buck Island Reef National Monument (BIRNM) St. Croix, USVI and adjacent waters. during October, 2005, widespread coral bleaching was observed within the ∼50 square-kilometer study area that was preceded by 10 wks of higher than average water temperatures (28.9–30.1 °C). Random transects (100 square meters) were conducted on linear reefs, patch reefs, bedrock, pavement, and scattered coral/rock habitats during October 2005, and April and October 2006, and species specific bleaching patterns were documented. During October 2005 approximately 51% of live coral cover was bleached. Nineteen of 23 coral species within 16 genera and two hydrocoral species exhibited signs of bleaching. Coral cover for Montastraea annularis and species of the genus Agaricia were the most affected, while other species exhibited variability in their susceptibility to bleaching. Bleaching was evident at all depths (1.5–28 m), was negatively correlated with depth, and positively correlated with habitat complexity. Bleaching was less prevalent at all depths and habitat types upon subsequent monitoring during April (15%) and October (3%) 2006. Four species and one genus did not exhibit signs of bleaching throughout the study period (Dendrogyra cylindrus, Eusmilia fastigata, Mussa angulosa, Mycetophyllia aliciae, Scolymia spp.).

Innovación en la enseñanza de la demostración en un curso de geometría para formación inicial de profesores

Durante el desarrollo de un curso de geometría plana para futuros profesores de matemáticas, profesora y estudiantes conforman una comunidad cuyo propósito es aprender a demostrar. La empresa del curso es construir un sistema axiomático para la geometría plana. Las tareas específicas están asociadas, en su mayoría, a situaciones problema cuya resolución involucra a los estudiantes en una actividad demostrativa en la que la geometría dinámica y la interacción social en el aula, gestionada por la profesora, juegan papeles esenciales. En este documento damos detalles de esta innovación.

Impact of human activities on benthic biotopes and species

Executive Summary 1. The Marine Life Information Network (MarLIN) has been developed since 1998. Defra funding has supported a core part of its work, the Biology and Sensitivity Key Information Sub-programme. This report relates to Biology and Sensitivity work for the period 2001-2004. 2. MarLIN Biology and Sensitivity research takes information on the biology of species to identify the likely effects of changing environmental conditions linked to human activities on those species. In turn, species that are key functional, key structural, dominant, or characteristic in a biotope (the habitat and its associated species) are used to identify biotope sensitivity. Results are displayed over the World Wide Web and can be accessed via a range of search tools that make the information of relevance to environmental management. 3. The first Defra contract enabled the development of criteria and methods of research, database storage methods and the research of a wide range of species. A contract from English Nature and Scottish Natural Heritage enabled biotopes relevant to marine SACs to be researched. 4. Defra funding in 2001-2004 has especially enabled recent developments to be targeted for research. Those developments included the identification of threatened and declining species by the OSPAR Biodiversity Committee, the development of a new approach to defining sensitivity (part of the Review of Marine Nature Conservation), and the opportunity to use Geographical Information Systems (GIS) more effectively to link survey data to MarLIN assessments of sensitivity. 5. The MarLIN database has been developed to provide a resource to 'pick-and-mix' information depending on the questions being asked. Using GIS, survey data that provides locations for species and biotopes has been linked to information researched by MarLIN to map the likely sensitivity of an area to a specified factor. Projects undertaken for the Irish Sea pilot (marine landscapes), in collaboration with CEFAS (fishing impacts) and with the Countryside Council for Wales (oil spill response) have demonstrated the application of MarLIN information linked to survey data in answering, through maps, questions about likely impacts of human activities on seabed ecosystems. 6. GIS applications that use MarLIN sensitivity information give meaningful results when linked to localized and detailed survey information (lists of species and biotopes as point source or mapped extents). However, broad landscape units require further interpretation. 7. A new mapping tool (SEABED map) has been developed to display data on species distributions and survey data according to search terms that might be used by an environmental manager. 8. MarLIN outputs are best viewed on the Web site where the most up-to-date information from live databases is available. The MarLIN Web site receives about 1600 visits a day. 9. The MarLIN approach to assessing sensitivity and its application to environmental management were presented in papers at three international conferences during the current contract and a 'touchstone' paper is to be published in the peer-reviewed journal Hydrobiologia. The utility of MarLIN information for environmental managers, amongst other sorts of information, has been described in an article in Marine Pollution Bulletin. 10. MarLIN information is being used to inform the identification of potential indicator species for implementation of the Water Framework Directive including initiatives by ICES. 11. Non-Defra funding streams are supporting the updating of reviews and increasing the amount of peer review undertaken; both of which are important to the maintenance of the resource. However, whilst MarLIN information is sufficiently wide ranging to be used in an 'operational' way for marine environmental protection and management, new initiatives and the new biotopes classification have introduced additional species and biotopes that will need to be researched in the future. 12. By the end of the contract, the Biology and Sensitivity Key Information database contained full Key Information reviews on 152 priority species and 117 priority biotopes, together with basic information on 412 species; a total of 564 marine benthic species.

On the structure and performance of a novel blind source separation based carrier phase synchronization error compensator

In this paper we carry out a detailed performance analysis of a novel blind-source-seperation (BSS) based DSP algorithm that tackles the carrier phase synchronization error problem. The results indicate that the mismatch can be effectively compensated during the normal operation as well as in the rapidly changing environments. Since the compensation is carried out before any modulation specific processing, the proposed method works with all standard modulation formats and lends itself to efficient real-time custom integrated hardware or software implementations.

La escritura de una historia : lectura de Bernal y de la conquista.

Expone un intento de lectura e interpretación de lo que en realidad significó aquel tipo de escritura nueva en relación con la aparición del nuevo mundo.Se basa en el planteamiento fundamental de que hoy existe suficiente documentación bibliografía como para poder encarar tales hechos con una objetividad mucho mayor de lo que ocurría en la vieja tradición del nacionalismo hispánico o de la leyenda negra.En definitiva, expone un análisis interpretativo y textual de la obra 'La Historia verdadera de la Conquista de la Nueva España' de Bernal Díaz del Castillo poniéndolo en relación con la historiografía literaria indiana de los siglos de oro y la literatura colonial de en América.

Design of a turn-linker-turn foldamer by incorporating meta-amino benzoic acid in the middle of a helix forming hexapeptide sequence: A helix breaking approach

Single crystal X-ray diffraction studies reveal that the incorporation of meta-amino benzoic acid in the middle of a helix forming hexapeptide sequence such as in peptide I Boc-Ile(1)-Aib(2)-Val(3)-m-ABA(4)-Ile(5)-Aib(6)-Leu(7)-OMe (Aib: alpha-amino isobutyric acid: m-ABA: meta-amino benzoic acid) breaks the helix propagation to produce a turn-linker-turn (T-L-T) foldamer in the solid state. In the crystalline state two conformational isomers of peptide I self-assemble in antiparallel fashion through intermolecular hydrogen bonds and aromatic pi-pi interactions to form a molecular duplex. The duplexes are further interconnected through intermolecular hydrogen bonds to form a layer of peptides. The layers are stacked one on top of the other through van der Waals interactions to form hydrophilic channels filled with solvent methanol. (C) 2009 Elsevier B.V. All rights reserved.

Meta-models, environment and layers: agent-oriented engineering of complex systems

Traditional software engineering approaches and metaphors fall short when applied to areas of growing relevance such as electronic commerce, enterprise resource planning, and mobile computing: such areas, in fact, generally call for open architectures that may evolve dynamically over time so as to accommodate new components and meet new requirements. This is probably one of the main reasons that the agent metaphor and the agent-oriented paradigm are gaining momentum in these areas. This thesis deals with the engineering of complex software systems in terms of the agent paradigm. This paradigm is based on the notions of agent and systems of interacting agents as fundamental abstractions for designing, developing and managing at runtime typically distributed software systems. However, today the engineer often works with technologies that do not support the abstractions used in the design of the systems. For this reason the research on methodologies becomes the basic point in the scientific activity. Currently most agent-oriented methodologies are supported by small teams of academic researchers, and as a result, most of them are in an early stage and still in the first context of mostly \academic" approaches for agent-oriented systems development. Moreover, such methodologies are not well documented and very often defined and presented only by focusing on specific aspects of the methodology. The role played by meta- models becomes fundamental for comparing and evaluating the methodologies. In fact a meta-model specifies the concepts, rules and relationships used to define methodologies. Although it is possible to describe a methodology without an explicit meta-model, formalising the underpinning ideas of the methodology in question is valuable when checking its consistency or planning extensions or modifications. A good meta-model must address all the different aspects of a methodology, i.e. the process to be followed, the work products to be generated and those responsible for making all this happen. In turn, specifying the work products that must be developed implies dening the basic modelling building blocks from which they are built. As a building block, the agent abstraction alone is not enough to fully model all the aspects related to multi-agent systems in a natural way. In particular, different perspectives exist on the role that environment plays within agent systems: however, it is clear at least that all non-agent elements of a multi-agent system are typically considered to be part of the multi-agent system environment. The key role of environment as a first-class abstraction in the engineering of multi-agent system is today generally acknowledged in the multi-agent system community, so environment should be explicitly accounted for in the engineering of multi-agent system, working as a new design dimension for agent-oriented methodologies. At least two main ingredients shape the environment: environment abstractions - entities of the environment encapsulating some functions -, and topology abstractions - entities of environment that represent the (either logical or physical) spatial structure. In addition, the engineering of non-trivial multi-agent systems requires principles and mechanisms for supporting the management of the system representation complexity. These principles lead to the adoption of a multi-layered description, which could be used by designers to provide different levels of abstraction over multi-agent systems. The research in these fields has lead to the formulation of a new version of the SODA methodology where environment abstractions and layering principles are exploited for en- gineering multi-agent systems.

Historiadores del Siglo XIX y la historia de América

Tabla de contenidos: Etapas de la historiografía latinoamericana. La imagen del pasado : Algunos debates. Tareas nacionalizadoras de la historia. La indagación del pasado. Historia narrativa versus historia filosófica. Cuestiones sobre el nombre específico de América. Las historias de América en el Siglo XIX. Historiadores de América anteriores a 1860. Historiadores de América en la segunda mitad del XIX.