Stable isotope ratios and chemistry on corals from the Caribbean Sea

Instrumental climate data are limited in length and only available with low spatial coverage before the middle of the 20th century. This is too short to reliably determine and interpret decadal and longer scale climate variability and to understand the underlying mechanisms with sufficient accuracy. A proper knowledge of past variability of the climate system is needed to assess the anthropogenic impact on climate and ecosystems, and also important with regard to long-range climate forecasting. Highly-resolved records of past climate variations that extend beyond pre-industrial times can significantly help to understand long-term climate changes and trends. Indirect information on past environmental and climatic conditions can be deduced from climate-sensitive proxies. Large colonies of massive growing tropical reef corals have been proven to sensitively monitor changes in ambient seawater. Rapid skeletal growth, typically ranging between several millimeters to centimeters per year, allows the development of proxy records at sub-seasonal resolution. Stable oxygen isotopic composition and trace elemental ratios incorporated in the aragonitic coral skeleton can reveal a detailed history of past environmental conditions, e.g., sea surface temperature (SST). In general, coral-based reconstructions from the tropical Atlantic region have lagged behind the extensive work published using coral records from the Indian and Pacific Oceans. Difficulties in the analysis of previously utilized coral archives from the Atlantic, typically corals of the genera Montastrea and Siderastrea, have so far exacerbated the production of long-term high-resolution proxy records. The objective of this study is the evaluation of massive fast-growing corals of the species Diploria strigosa as a new marine archive for climate reconstructions from the tropical Atlantic region. For this purpose, coral records from two study sites in the eastern Caribbean Sea (Guadeloupe, Lesser Antilles; and Archipelago Los Roques, Venezuela) were examined. At Guadeloupe, a century-long monthly resolved multi-proxy coral record was generated. Results present the first d18O (Sr/Ca)-SST calibration equations for the Atlantic braincoral Diploria strigosa, that are robust and consistent with previously published values using other coral species from different regions. Both proxies reflect local variability of SST on a sub-seasonal scale, which is a precondition for studying seasonally phase-locked climate variations, as well as track variability on a larger spatial scale (i.e., in the Caribbean and tropical North Atlantic). Coral Sr/Ca reliably records local annual to interannual temperature variations and is higher correlated to in-situ air temperature than to grid-SST. The warming calculated from coral Sr/Ca is concurrent with the strong surface temperature increase at the study site during the past decades. Proxy data show a close relationship to major climate signals from the tropical Pacific and North Atlantic (the El Niño Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO)) affecting the seasonal cycle of SST in the North Tropical Atlantic (NTA). Coral oxygen isotopes are also influenced by seawater d18O (d18Osw) which is linked to the hydrological cycle, and capture large-scale climate variability in the NTA region better than Sr/Ca. Results from a quantitative comparison between extreme events in the two most prominent modes of external forcing, namely the ENSO and NAO, and respective events recorded in seasonal coral d18O imply that SST variability at the study site is highly linked to Pacific and North Atlantic variability, by this means supporting the assumptions of observational- and model-based studies which suggest a strong impact of ENSO and NAO forcings onto the NTA region through a modulation of trade wind strength in winter. Results from different spectral analysis tools suggest that interannual climate variability recorded by the coral proxies is II largely dictated by Pacific ENSO forcing, whereas at decadal and longer timescales the influence of the NAO is dominan. tThe Archipelago Los Roques is situated in the southeastern Caribbean Sea, north of the Venezuelan coast. Year-to-year variations in monthly resolved coral d18O of a nearcentury- long Diploria strigosa record are significantly correlated with SST and show pronounced multidecadal variations. About half of the variance in coral d18O can be explained by variations in seawater d18O, which can be estimated by calculating the d18Oresidual via subtracting the SST component from measured coral d18O. The d18Oresidual and a regional precipitation index are highly correlated at low frequencies, suggesting that d18Osw variations are primarily atmospheric-driven. Warmer SSTs at Los Roques broadly coincide with higher precipitation in the southeastern Caribbean at multidecadal time scales, effectively strengthening the climate signal in the coral d18O record. The Los Roques coral d18O record displays a strong and statistically significant relationship to different indices of hurricane activity during the peak of the Atlantic hurricane season in boreal summer and is a particularly good indicator of decadal-multidecadal swings in the latter indices. In general, the detection of long-term changes and trends in Atlantic hurricane activity is hampered due to the limited length of the reliable instrumental record and the known inhomogeneity in the observational databases which result from changes in observing practice and technology over the years. The results suggest that coral-derived proxy data from Los Roques can be used to infer changes in past hurricane activity on timescales that extend well beyond the reliable record. In addition, the coral record exhibits a clear negative trend superimposed on the decadal to multidecadal cycles, indicating a significant warming and freshening of surface waters in the genesis region of tropical cyclones during the past decades. The presented coral d18O time series provides the first and, so far, longest continuous coral-based record of hurricane activity. It appears that the combination of both signals (SST and d18Osw) in coral d18O leads to an amplification of large-scale climate signals in the record, and makes coral d18O even a better proxy for hurricane activity than SST alone. Atlantic hurricane activity naturally exhibits strong multidecadal variations that are associated with the Atlantic Multidecadal Oscillation (AMO), the major mode of lowfrequency variability in the North Atlantic Ocean. However, the mechanisms underlying this multidecadal variability remain controversial, primarily because of the limited instrumental record. The Los Roques coral d18O displays strong multidecadal variability with a period of approximately 60 years that is closely related to the AMO, making the Archipelago Los Roques a very sensitive location for studying low-frequency climate variability in the Atlantic Ocean. In summary, the coral records presented in this thesis capture different key climate variables in the north tropical Atlantic region very well, indicating that fast-growing Diploria strigosa corals represent a promising marine archive for further proxy-based reconstructions of past climate variability on a range of time scales.

Process of Expropriation of Buildings for the Construction of the New Dock of the Port of Cartagena (Spain) in the 18th Century

The need of the Bourbon monarchy to build a Naval Base in the Bay of Cartagena (Spain) during the eighteenth century, implied performing various actions on the environment which allowed the construction of the new dock. One of the priority actions was the transformation of the watershed of the streams that flowed into Mandaraches´s sea. For this reason, a dike was designed and constructed in the northern part of the city. The design of this great work, which was designed as a fortification of the city, was subject to considerable uncertainties. Its proximity to the city involved the demolition of several buildings in the San Roque´s neighborhood. The greater or lesser number of affected buildings and the value of the just indemnification for the expropriation of them, become decisive factors to determine if the work was viable for the Royal Estate or not.

Análisis de la distribución espacial de centros eruptivos monogenéticos en las Islas Canarias según el análisis de vecino más próximo de Poisson.

El objetivo principal de este trabajo es estudiar la distribución espacial de los centros eruptivos monogenéticos según el análisis de vecino más próximo de Poisson, propuesto por Clark y Evans (1954), en las Islas Canarias. Se pretende adquirir así unos valores cuantitativos que permitan interpretar si los centros eruptivos monogenéticos se distribuyen de forma aleatoria, concentrada o dispersa en cada isla. La confrontación de estos resultados con la bibliografía ayudará a interpretarlos mediante comparación. Como objetivo secundario y parte fundamental del trabajo se presenta la necesidad y el fin de adquirir conocimientos teóricos y prácticos de análisis espacial, además de destreza en el uso de lenguajes y entornos de programación adecuados para este tipo de estudios. Otro de los objetivos es desarrollar una aplicación que haga extensible este tipo de estudios de forma sencilla y ponga a disposición, en el caso de una publicación final, de la comunidad científica y de los usuarios a nivel universitario, una herramienta eficaz de análisis cuantitativo para hallar los índices requeridos para llevar a cabo el análisis de vecino más próximo de Poisson. El área de estudio son las Islas Canarias que conforman un archipiélago de siete islas mayores (Fig. 1): Tenerife, Fuerteventura, Gran Canaria, Lanzarote, La Palma, La Gomera y El Hierro; cuatro islas menores: Lobos, La Graciosa, Montaña Clara y Alegranza; y varios roques. Queda comprendido entre los paralelos 27 º 37 ' N y 29 º 35 ' N (Punta de La Restinga, en El Hierro; Punta de los Mosegos, en la isla de la Alegranza) y entre los meridianos 13 º 20 ' W y 18 º 10 ' W (Roque del Este; Punta de Orchilla, en El Hierro) y se encuentra a distancias de entre 100 km y 500 km de la costa noroccidental africana. Queda englobado dentro de la región de la Macaronesia, conjunto de cinco archipiélagos de origen volcánico situado en el Atlántico Oriental, a saber: Azores, Madeira, Salvajes, Canarias y Cabo Verde; y está limitada por los paralelos 14 º 49 ' N y 39 º 45 ' N, y por los meridianos 13 º 20 ' W y 31 º 17 ' W, estando separados entre sus puntos norte y sur por 2 700 km y entre sus puntos este y oeste por 1 800 km de distancia (Gosálvez et al., 2010). Sobre el origen del archipiélago y su contexto geodinámico, se han propuesto varias hipótesis, e.g.: Carracedo et al. (1998), Anguita y Hernán (2000), Ancochea et al. (2006), en las que aún no queda completamente claro el origen de la Islas Canarias, ya que algunos dan un protagonismo mayor a la actividad tectónica como causante del ascenso del magma a través de la corteza y otros defienden la existencia de un punto caliente como verdadera causa del volcanismo en Canarias.

Aminopeptidase A inhibitors as potential central antihypertensive agents

Overactivity of the brain renin-angiotensin system (RAS) has been implicated in the development and maintenance of hypertension in several experimental models, such as spontaneously hypertensive rats and transgenic mice expressing both human renin and human angiotensinogen transgenes. We recently reported that, in the murine brain, angiotensin II (AngII) is converted to angiotensin III (AngIII) by aminopeptidase A (APA), whereas AngIII is inactivated by aminopeptidase N (APN). If injected into cerebral ventricles (ICV), AngII and AngIII cause similar pressor responses. Because AngII is metabolized in vivo into AngIII, the exact nature of the active peptide is not precisely determined. Here we report that, in rats, ICV injection of the selective APA inhibitor EC33 [(S)-3-amino-4-mercaptobutyl sulfonic acid] blocked the pressor response of exogenous AngII, suggesting that the conversion of AngII to AngIII is required to increase blood pressure (BP). Furthermore, ICV injection, but not i.v. injection, of EC33 alone caused a dose-dependent decrease in BP by blocking the formation of brain but not systemic AngIII. This is corroborated by the fact that the selective APN inhibitor, PC18 (2-amino-4-methylsulfonyl butane thiol), administered alone via the ICV route, increases BP. This pressor response was blocked by prior treatment with the angiotensin type 1 (AT1) receptor antagonist, losartan, showing that blocking the action of APN on AngIII metabolism leads to an increase in endogenous AngIII levels, resulting in BP increase, through interaction with AT1 receptors. These data demonstrate that AngIII is a major effector peptide of the brain RAS, exerting tonic stimulatory control over BP. Thus, APA, the enzyme responsible for the formation of brain AngIII, represents a potential central therapeutic target that justifies the development of APA inhibitors as central antihypertensive agents.

Identification of metabolic pathways of brain angiotensin II and III using specific aminopeptidase inhibitors: predominant role of angiotensin III in the control of vasopressin release.

Angiotensin (Ang) II and Ang III are two peptide effectors of the brain renin-angiotensin system that participate in the control of blood pressure and increase water consumption and vasopressin release. In an attempt to delineate the respective roles of these peptides in the regulation of vasopressin secretion, their metabolic pathways and their effects on vasopressin release were identified in vivo. For this purpose, we used recently developed selective inhibitors of aminopeptidase A (APA) and aminopeptidase N (APN), two enzymes that are believed to be responsible for the N-terminal cleavage of Ang II and Ang III, respectively. Mice received [3H]Ang II intracerebroventricularly (i.c.v.) in the presence or absence of the APN inhibitor, EC33 (3-amino-4-thio-butyl sulfonate) of the APN inhibitor, EC27 (2-amino-pentan-1,5-dithiol). [3H]Ang II and [3H]Ang III levels were evaluated from hypothalamus homogenates by HPLC. EC33 increased the half-life of [3H]Ang II 2.6-fold and completely blocked the formation of [3H]Ang III, whereas EC27 increased the half-life of [3H]Ang III 2.3-fold. In addition, the effects of EC33 and EC27 on Ang-induced vasopressin release were studied in mice. Ang II was injected i.c.v. in the presence or absence of EC33, and plasma vasopressin levels were estimated by RIA. While vasopressin levels were increased 2-fold by Ang II (5 ng), EC33 inhibited Ang II-induced vasopressin release in a dose-dependent manner. In contrast, EC27 injected alone increased in a dose-dependent manner vasopressin levels. The EC27-induced vasopressin release was completely blocked by the coadministration of the Ang receptor antagonist (Sar1-Ala8) Ang II. These results demonstrate for the first time that (i) APA and APN are involved in vivo in the metabolism of brain Ang II and Ang III, respectively, and that (ii) the action of Ang II on vasopressin release depends upon the prior conversion of Ang II to Ang III. This shows that Ang III behaves as one of the main effector peptides of the brain renin-angiotensin system in the control of vasopressin release.

LSA silicon material task closed-cycle process development : interim summary report, August-December 1978 /

Includes bibliographical references (page 37).

Lexique des antiquités grecques;

Mode of access: Internet.

Histoire des champignons comestibles et vénéneux : où l'on expose leurs caractères distinctifs, leurs propriétés alimentaires et économiques, leurs effets nuisibles et les moyens de s'en garantir ou d'y remédier /

Includes indexes.

Histoire des champignons comestibles et vénéneux : ornée de figures coloriées représentant les principales espéces dans leurs dimensions naturelles ; où l'on expose leurs caractères distinctifs, leurs propriétés alimentaires et économiques, leurs effets nuisibles et les moyens de s'en garantir ou d'y remédier, ouvrage utile aux amateurs de champignons, aux médicins, aux naturalistes ... etc. /

Stafleu and Cowan, 2d ed.

Phytographie médicale : ornée de figures coloriées de grandeur naturelle, ou l'on expose l'histoire des poisons tirés du règne végétal, et les moyens de remédier a leurs effets délétères ; avec des observations sur les propriétés et les usages des plantes héroïques /

Includes indexes.

Plantes usuelles, indigènes et exotiques, dessinées et coloriées d'après nature, avec la description de leurs caractères distinctifs et de leurs propriétés médicales.

Vol. 1 has engraved colored title-page.

Mélanges de littérature française du moyen âge,

"Nous réunissons ... des mémoires insérés par Gaston Paris dans les publications collectives qui sont parfois difficilement accessible."--Avertissement.

Cortège : extrait de la Petite suite à 4 mains /

Part for violin.