902 resultados para Save the Bay
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Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records.
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Maerl community respiration, photosynthesis and calcification were measured seasonally in the Bay of Brest (France). The dynamics of oxygen, carbon and carbonate fluxes at the water-sediment interface were assessed using benthic chambers. Community respiration (CR) fluctuated in accordance with the seasonal changes in water temperature, from 1.5 mmol C m**-2 h**-1 in winter to 8.7 mmol C m**-2 h**-1 in summer. Mean gross community production (GCP) varied significantly among seasons, according to incident irradiance and temperature, from 3.4 mmol C m**-2 h**-1 in winter to 12.7 mmol C m-2 h-1 in summer. Mean annual Pmax for the P-E curve was estimated to 13.3 mmol C m-2 h-1. Carbonate precipitation only occurred during light incubations and varied seasonally from 0.7 mmol CaCO3 m-2 h-1 in winter to 4.2 mmol CaCO3 m-2 h-1 in summer. Mean annual Pmax was 3.2 mmol CaCO3 m-2 h-1. Annual CR was estimated to 407.4 g C m**-2 yr**-1, and GCP, to 240.9 g C m**-2 yr**-1. Maerl communities are, therefore, heterotrophic systems (GCP:CR = 0.6), and are a source of CO2 for surrounding environments. In addition, CO2 released by calcification averaged 39.2 g C m**-2 yr**-1. Maerl community annual carbonate production was estimated to 486.7 g CaCO3 m**-2 yr**-1; they are therefore one of the most important carbonate producers in shallow coastal waters.
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We have compiled results obtained from four high sedimentation rate hemipelagic sequences from the Celtic sector of the NW European margin (NE Atlantic) to investigate the paleoceanographic and paleoclimatic evolution of the area over the last few climatic cycles. We focus on periods characteristic of deglacial transitions. We adopt a multiproxy sedimentological, geochemical, and micropaleontological approach, applying a sampling resolution down to ten microns for specific intervals. The investigation demonstrates the relationships between the Bay of Biscay hydrography and the glacial/deglacial history of both the proximal British-Irish Ice Sheet (BIIS) and the western European continent. We identify recurrent phases of laminae deposition concurrent with major BIIS deglacial episodes in all the studied cores. Evidence for abrupt freshwater discharges into the open ocean highlights the influence of such events at a regional scale. We discuss their impact at a global scale considering the present and past key location of the Bay of Biscay versus the Atlantic Meridional Overturning Circulation (AMOC).
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Recreational fisheries in North America are valued between $47.3 billion and $56.8 billion. Fisheries managers must make strategic decisions based on sound science and knowledge of population ecology, to effectively conserve populations. Competitive fishing, in the form of tournaments, has become an important part of recreational fisheries, and is common on large waterbodies including the Great Lakes. Black Bass, Micropterus spp., are top predators and among the most sought after species in competitive catch-and-release tournaments. This study investigated catch-and-release tournaments as an assessment tool through mark-recapture for Largemouth Bass (>305mm) populations in the Tri Lakes, and Bay of Quinte, part of the eastern basin of Lake Ontario. The population in the Tri Lakes (1999-2002) was estimated to be stable between 21,928-29,780, and the population in the Bay of Quinte (2012-2015) was estimated to be between 31,825-54,029 fish. Survival in the Tri Lakes varied throughout the study period, from 31%-54%; while survival in the Bay of Quinte remained stable at 63%. Differences in survival may be due to differences in fishing pressure, as 34-46% of the Largemouth Bass population on the Tri Lakes is harvested annually and only 19% of catch was attributed to tournament angling. Many biological issues still surround catch-and-release tournaments, particularly concerning displacement from initial capture sites. In the past, the majority of studies have focused on small inland lakes and coastal areas, displacing bass relatively short distances. My study displaced Largemouth and Smallmouth Bass up to 100km, and found very low rates of return; only 1 of 18 Largemouth Bass returned 15 km and 1 of 18 Smallmouth Bass returned 135 km. Both species remained near the release sites for an average of approximately 2 weeks prior to dispersing. Tournament organizers should consider the use of satellite release locations to facilitate dispersal and prevent stockpiling at the release site. Catch-and-release tournaments proved to be a valuable tool in assessing population variables and the effects of long distance displacement through the use of mark recapture and acoustic telemetry on large lake systems.
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El derecho a ser escuchado y participar en aquellos asuntos que afectan a los niños es un derecho fundamental de la infancia escasamente respetado por el adulto, quien tiende a silenciar su voz, infravalorando su visión y posible aportación. Ante esta realidad, la Escuela Infantil se erige como un marco privilegiado para la escucha y la participación de la infancia en aquellos temas que les afectan, contribuyendo a la formación de ciudadanos democráticos. A partir de un marco de escucha donde se concibe al pequeño como un sujeto activo, competente y experto en su propia vida, se ha llevado a cabo una investigación que ha adoptado el formato de estudio de caso, en la que se ha recogido a través de las técnicas del dibujo y de las conversaciones con niños, la visión que poseen los más pequeños sobre la Escuela Infantil, analizando el bienestar del niño en el contexto escolar, el sentido y finalidad que los niños otorgan a la escuela; el grado de satisfacción con la misma; sus gustos y preferencias en el contexto escolar; la autonomía y libertad que dicen poseer en la escuela; su visión sobre los aspectos organizativos que rigen el funcionamiento del centro y su perspectiva sobre cómo es y cómo les gustaría que fuera la participación de las familias en la escuela. Finalmente, se recogen sus propuestas de mejora para hacer de la Escuela Infantil a la que asisten su escuela ideal. Los resultados del estudio ponen de manifiesto la demanda de los niños de una Escuela Infantil diferente a la que conocen y la existencia de un pensamiento divergente del pensamiento adulto que es necesario escuchar y tener en consideración, siendo sus aportaciones de gran valía para poder iniciar procesos de innovación y mejora educativa.
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La investigación que se presenta fue desarrollada dentro del campo de los estudios regionales y con visión transdisciplinar. Tuvo como objetivo deconstruir conjuntamente con los participantes, las capacidades humanas regionales de nosotros los docentes de educación básica, en nuestros procesos de reflexión entre teoría y práctica, en los que se consideraron las condicionantes estructurales, en niveles macro y micro regionales, con el alcance de haber identificado el potencial de cambio en nuestra praxis de docente como acción ante nuestros alumnos, quienes configuran el tejido social de Tuxtla Gutiérrez. Desde una perspectiva sociocrítica, se tomó como punto de fuga o núcleo la teoría crítica con fundamento filosófico en la escuela de Fráncfort y con una postura epistemológica basada en el construccionismo por la estrecha relación sujeto-objeto en el estudio; por ende se empleó la metodología investigaciónacción a través de diversas técnicas e instrumentos. Los resultados fueron concentrados en categorías que facilitaron su discusión: primeramente con el potencial de cambio, que adquirió significado mediante el desarrollo de las capacidades de reflexión y conciencia del docente; luego se presentaron las capacidades humanas, de nosotros los docentes, en las que destacaron como base de otras, las capacidades de amor, autoestima y compromiso. Posteriormente, se describió la reflexión docente sobre la concepción del beneficio personal hacia el beneficio colectivo. Finalmente, se discutió sobre la proyección de la acción docente dentro de la relación alumno y región. Se concluyó que las capacidades humanas y el potencial de cambio, deconstruidos conjuntamente con los docentes participantes, fueron la respuesta del proceso investigativo en un determinado tiempo y espacio, como posibilidades de acción docente hacia la tan deseada transformación socioeducativa regional.
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La actual ciudad de Akko in Israel, ha tenido muchos nombres a lo largo de los siglos de su prolongado asentamiento. El nombre de Acre, con el que se le conoce en el mundo Occidental, es el residuo del nombre de San Juan de Acre que le dieron sus habitantes cruzados en el s. XII de la era Cristiana. Sin embargo, el nombre de ‘Akko y sus derivados, tienen una larga historia. Bajo tal nombre, aparece ya en las fuentes escritas de comienzos el II Milenio a.C., cuando e produjo la primera urbanización del lugar. Se mantuvo como ‘Akko, ‘Ake, etc…a lo largo de los siglos posteriors, a pesar de los inentos de varios dirigentes de cambiarelo. El asentamiento se trasladó, a causa de los cambios en la línea de costa y del río Na’aman o Belos, desde el antiguo Tel Akko a la bahía, en la que se estableció un puerto artificial,reconstruido y renovado reiteradamente durante más de 2000 años. El primer nombre conocido del sitio original del asentamiento, el tell, data de época de los cruzados. Este sufrió una alteración de su nombre, reflejo de la transformación de la historia de Akko, en la que la intervención occidental (europea9, jugó un papel decisivo.
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Thesis (Master's)--University of Washington, 2016-06
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Dagens dataloggare har många funktioner vilket avspeglas i programvaran som används för att kommunicera med dem. De har fler funktioner än vad enskilda företag och privatpersoner behöver vilket gör programvaran onödigt komplicerad. Genom att minska antalet inställningsmöjligheter kan programvaran göras mindre, snabbare och lättare att lära sig. Arbetet utfördes hos Inventech Europe AB som tillhandahöll dataloggare för temperatur- och fuktighetsmätning. De ville undersöka möjligheterna att utveckla ett program som personer med begränsad datorvana snabbt kunde lära sig att använda. Därför var syftet med detta arbete att utreda hur ett sådant program kunde se ut. Arbetets fokus låg på designprocessen. Genom olika UML-diagram visualiserades de olika momenten i processen. Då projektet var relativt litet valdes en utvecklingsprocess som följer vattenfallsmodellen där de olika stegen (specifikation, design, implementation, test) utförs i följd. Det förutsätter att ett steg är färdigt innan nästa steg påbörjas. Modellen fungerar bäst när projektet är mindre och väldefinierat. Tyvärr ändrades företagets krav på hur programmet skulle fungera flera gånger under arbetets gång. Därmed borde en mer flexibel utvecklingsprocess ha valts för att ge utrymme för förändringar som kunde uppkomma under projektets gång. Slutresultatet blev en funktionsprototyp som var lätt att använda och inte hade fler inställningsmöjligheter än nödvändigt. Funktionsprototyp kan användas som bas för att lägga till egen skräddarsydd funktionalitet. För att visa detta inkluderades ytterligare två funktioner. En av funktionerna var möjligheten att kunna spara insamlad data till en extern databas som sedan kunde användas som källa till andra program vilka exempelvis skulle kunna visualisera data med hjälp av olika grafer. För att lätt kunna identifiera olika inkopplade dataloggare inkluderades även möjligheten att namnge de olika enheterna.
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This work is part of the program, "recruitment determinism in scallops" initiated in 1992 by the "Contrat de Baie". The aim of this research was to explain interannual abundance fluctuations observed for Pecten maximus, in the Bay of Brest. To this end an analytical approach to the life cycle of the species was undertaken to determine its critical phases. A phase may be considered as "critical" if the mortality rate at its level varies from one year to the other. Using data from 1989 to 1994, a precise time-table of the "physiological year" of the scallop in the Bay of Brest was determined. Fecundity and gamete production kinetics were estimated from the annual variation in the weight indices of the gonad. In the laboratory, egg quality was estimated following stimulated spawning of newly caught individuals. The digestive activity was estimated by amylase activity measurements during a three year period. Spawning lasts 6 months in the Bay of Brest from March to October. Spawning, muscle and digestive gland growths, are intimately linked to phytoplancton blooms. Gonad production shows a maximum in April-May, and two relative minima in Match and November. These results, which provide detailed understanding of the adult's annual cycle in the Bay of Brest, will be used to interpret the relationship between the annual cycle and larval and post larval abundance and survival. Already, these results are being used to improve spat production in hatcheries.
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The mainstay of Big Data is prediction in that it allows practitioners, researchers, and policy analysts to predict trends based upon the analysis of large and varied sources of data. These can range from changing social and political opinions, patterns in crimes, and consumer behaviour. Big Data has therefore shifted the criterion of success in science from causal explanations to predictive modelling and simulation. The 19th-century science sought to capture phenomena and seek to show the appearance of it through causal mechanisms while 20th-century science attempted to save the appearance and relinquish causal explanations. Now 21st-century science in the form of Big Data is concerned with the prediction of appearances and nothing more. However, this pulls social science back in the direction of a more rule- or law-governed reality model of science and away from a consideration of the internal nature of rules in relation to various practices. In effect Big Data offers us no more than a world of surface appearance and in doing so it makes disappear any context-specific conceptual sensitivity.
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The aim of this report is to provide biomass estimates (AFDW, g.m-2 ) of the four main components of the benthic food web in the southern part of the Bay of St-Brieuc: suspension-feeders, deposit-feeders, herbivores and carnivores. Patterns in the environmental data (i.e., sedimentary characters) are first analysed, and then related to the spatial distribution of communities ; both approaches use classical ordination techniques (PCA, correspondence analysis). A second typology, based on a review of published litterature concerning coastal macrozoobenthos feeding, ascribes each taxonomic unit to a trophic group. Finally, quantitative results are thus given per biota ; suspension-feeders appear to dominate (in terms of biomass) most of fine-sand habitats of the studied area.
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New high-resolution seismic data complemented with bedrock samples allowed us to propose a revised geological map of the Bay of Seine and to better define the control by the geological substrate on the morphogenesis and evolution of the Seine River during Pleistocene times. The new data confirm previous works. The Bay of Seine can be divided into two geological parts: a Mesozoic monocline domain occupying most of the bay and a syncline domain, mostly Tertiary, in the north, at the transition with the Central English Channel area. The highlighting of Eocene synsedimentary deformations, marked by sliding blocks in the syncline domain, is one of the most original inputs of this new study in the Bay of Seine that underlines the significant role of the substrate on the formation of the Seine paleo-valley. In the monocline domain, three terraces, pre-Saalian, Saalian and Weischelian in age respectively, constitute the infill of the paleovalley, preferentially incised into the middle to upper Jurassic marl-dominated formations, and bounded to the north by the seaward extension of the Oxfordian cuesta. The three terraces are preserved only along the northern bank of the paleovalley, evidencing a NE-to-SW migration of the successive valleys during the Pleistocene. We assume this displacement results from the tectonic tilt of the Paris Basin western margin. In the North, the paleo-Seine is incised into the axis of the tertiary syncline, and comprises three fill terraces that are assumed to have similar ages than those of the terraces. The fill terrace pattern is associated to the subsiding character of this northern domain of the Bay of Seine.
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This work presents interactions between quantitative and qualitative river freshwater inputs and the shellfish farming (oyster and mussel) in the Pertuis Charentais. The quantity of freshwater (i.e. salinity) seems to have a weak influence on the shellfish farming contrarily to its quality determined by particulate and dissolved matters contained in the water. In autumn and winter, large precipitations have a "globally positive" effect amending the coastal ecosystem. Associated dissolved nutriments and the organic matter largely determine the quality of the coming spring growth for bred shellfish, itself controlling in turn the annual yield efficiencies. However, in winter their effects are postponed because of strong mineral load, low luminosity and temperature, then limiting the primary production. The spring contributions, directly linked to territorial practices, agriculture and tourism are more variable in quantity and quality from one year to another. They often correspond to high-risk inflows since numerous substances from anthropogenic watersheds can be found diluted in the coastal zone as in the Pertuis Charentais. Their impacts on in situ estuarine ecosystems are still poorly known since these substances are mainly studied and estimated in laboratory in controlled conditions. Several studies showed anthropogenic contaminations (i.e. cadmium, pesticides) could have significant direct or indirect effects on shellfish farming. For instance, the "summer" mortalities between 1990 and 2000 in the South of the Marennes-Oléron bay (MOB), that induced environmental and physiological oyster disorders, could be linked to pesticide effects, measured during consecutive years on the oyster bed of Ronce Perquis in the South of the MOB. The weak results from the spring larval rearing of the IFREMER experimental hatchery in the South of the bay, and chromosomal abnormalities measured on the stocks of wild oysters of the Pertuis could confirm a high-risk spring environment for the shellfish farming. In summer terrestrial inputs are reduced by low precipitations, anthropogenic water removals (drinking water, irrigation) and by plant evapotranspiration. Consequently certain years, a significant salinity increase in water masses of the Pertuis Charentais is observed. However, based on long-term observations, the significant interannual variability noticed in freshwater contributions constitutes one of the most important facts of these last years. When contributions are weak (i.e. 1991 and 2011), the mean annual salinity is 34.5 in the MOB. To the contrary, other years (i.e. 1977, 1981, 1983 and 1988), the mean salinity reduced to 30.5 shows the significant freshwater contributions to the bay. Elsewhere, particularly in the mediterranean region, oyster breeding water conditions characterized by high salinity values show the freshwater does not seem to be necessary for biological functions of the Pacific oyster Crassostrea gigas. Indeed, the oyster embryonic life in particular is well adapted to high salinity values as long as trophic resources are substantial and temperatures remain high. These two factors firstly condition the embryonic survival before the water salinity. Besides, in the Pertuis Charentais, wind conditions and the geographical bloodstock position rather determine the success of the larvae capture than seawater physic-chemical conditions. Finally, a misunderstanding still remains on summer freshwater contributions to the oyster larvae food supply.
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Knowledge of how biota can be used to monitor ecosystem health and assess impacts by human alterations such as land use and management measures taken at different spatial scales is critical for improving the ecological quality of aquatic ecosystems. This knowledge in Uganda is very limited or unavailable yet it is needed to better understand the relationship between environmental factors at different spatial scales, assemblage structure and taxon richness of aquatic ecosystems. In this study, benthic invertebrate community patterns were sampled between June 2001 and April 2002 and analysed in relation to water quality and catchment land use patterns from three shallow near-shore bays characterized by three major land uses patterns: urban (Murchison Bay); semi-urban (Fielding Bay); rural (Hannington Bay). Variations in density and guild composition of benthic macro-invertebrates communities were evaluated using GIS techniques along an urban-rural gradient of land use and differences in community composition were related to dissolved oxygen and conductivity variation. Based on numerical abundance and tolerance values, Hilsenhoff's Biotic Index ofthe invertebrates was determined in order to evaluate the relative importance of water quality in the three bays. Murchison Bay supported a relatively taxa-poor invertebrate assemblage mainly comprising stenotopic and eurytopic populations of pollution-tolerant groups such as worms and Chironomus sp. with an overall depression in species diversity. On the contrary, the communities in Fielding and Hannington bays were quite similar and supported distinct and diverse assemblages including pollution-intolerant forms such as Ephemeroptera (mayflies), Odonata (dragonflies). The Hilsenhoff Biotic Index in Murchison Bay was 6.53. (indicating poor water quality) compared to 6.34 for Fielding Bay and 5.78 for Hannington Bay (both indicating fair water quality). The characterization of maximum taxa richness balanced among taxa groups with good representation of intolerant individuals in Hannington Bay relative to Fielding and Murchison bays concludes that the bay is the cleanest in terms of water quality. Contrary, the dominance of few taxa with many tolerant iqdividuals present in Murchison Bay indicates that the bay is degraded in terms of water quality. These result are ofimportance when planning conservation and management measures, implementing large-scale biomonitoring programs, and predicting how human alterations (e.g nutrient loading) affect water ecosystems. Therefore, analysis of water quality in relation to macro-invertebrate community composition patterns as bio-indicators can lead to further understanding of their responses to environmental manipulations and perturbations.