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A MIP-based flow-through fluoroimmunosensor as an alternative to immunosensors for the determination of digoxin serum samples
(Springer, 2009-01-09) Durand Alegría, Jesús Senén; Paniagua González, Gema; Fernández Hernando, Pilar
This work reports a comparative study of two automated flow-through fluorosensors for the determination of digoxin in serum samples: an immunosensor with an anti-digoxin polyclonal antibody as the reactive phase permanently immobilized on CPG, and a sensor with a selective reaction system based on a methacrylic molecularly imprinted polymer (MIP) synthesized by bulk polymerisation. The variables affecting the sensitivity and dynamic range of the sensors (e.g., the carrier and elution solutions, flow-rates, pH and reagent concentrations) were optimised and the binding characteristics of their reactive phases compared in a competitive fluorescent assay. Digoxin was reproducibly determined by both sensors at the mg L-1 level (detection limit= 1.20×10-3 mg L-1 and RSD= 4-7% for the immunosensor; detection limit= 1.7×10-5 mg L-1 and RSD= 1-2% for the MIP sensor). No cross reactivity with digoxinrelated compounds was seen for either sensor at a digoxin:interferent ratio of 1:100. The lifetime of the immunosensor was about 50 immunoassays; its shelf life, when unused, is about three months. The lifetime of the MIP sensor was over 18 months. Both sensors were used to determine the digoxin concentration of human serum samples with satisfactory results.
A morphological study of molecularly imprinted polymers using the scanning electron microscope
(Elsevier, 2006-01) Durand Alegría, Jesús Senén; Paniagua González, Gema; Fernández Hernando, Pilar
Molecular imprinting is an emerging technique for producing polymers with applications in affinity-based separation, in biomimetic sensors, in catalysis, etc. This variety of uses relies upon the production of polymers with different affinities, specificities, sensitivities and loading capacities. Research into the development of molecular imprinted polymers (MIPs) with new or improved morphologies – which involves modification of the polymerisation process – is therefore underway. This paper reports a comparative study of non-covalent MIPs synthesised by “bulk” polymerisation using digoxin as template. These were synthesised under different conditions, i.e., changing the functional monomers employed (methacrylic acid or 2-vinylpyridine), the porogens (acetonitrile or dichloromethane) used, and by altering the volume of the latter. The polymerisation process was allowed to proceed either under UV light or in a thermostat-controlled waterbath. The surface morphology (was determined by scanning electron microscopy) and the ability of the different polymers to selectively rebind the template was then evaluated.
A pressure indicator for the impact of Iberian wild goat on moss and soils in a Mediterranean climate
(Springer, 2021) Aroztegui Vélez, Javier; López‑Sánchez, Aida; Peláez Beato, Marta; Perea García-Calvo, Ramón; García Rodríguez, Manuel
In the Sierra de Guadarrama National Park (central Spain), the population of Iberian wild goat, also known as Spanish ibex (Capra pyrenaica) has grown strongly since its reintroduction three decades ago. The plant community is now under heavy browsing pressure due to this high population. A study of the presence of moss on rocks was used herein as the basis for the design of an indicator, named impact on mosses (im), to describe the environmental pressure exerted by the Iberian wild goat in terms of moss removal. Granite and gneiss zones at medium altitudes with continental Mediterranean climate are the most suitable areas for successful application of the indicator. The hypotheses to test are: (1) the indicator will discriminate between areas with different wild goat pressure levels, (2) wild goat pressure will explain a high proportion of moss loss variance, and (3) the im indicator will be useful to establish a mathematical model between wild goat pressure and moss loss. The proposed indicator was analyzed using both statistical and data science techniques. The results support the mentioned hypotheses. Specifically, statistically significant differences were found regarding the impact on mosses between areas with different levels of Iberian wild goat pressure. Thus, a high proportion of the variance was associated with wild goat pressure (80% for high-pressure areas, 56% for low-pressure areas). A modified parabolic function was fit to express the relationship between Iberian wild goat pressure and impact on mosses. In conclusion, the im indicator was shown to be a useful tool to assess pressure due to Iberian wild goat. Therefore, im can help assess and manage Iberian wild goat populations and determine their sustainable levels.
Abrupt environmental changes during the last glacial cycle in Western Mediterranean (Formentera Island, Balearic archipelago, Spain)
(Elsevier, 2022) Bardají Azcárate, Teresa; Roquero García-Casal, Elvira; Cabero del Río, Ana; Zazo Cardeña, Caridad; Goy Goy, José Luis; Dabrio, Cristino José; Machado, María J.; Silva Barroso, Pablo Gabriel; Martínez Graña, Antonio Miguel; Lario Gómez, Javier
A sedimentary sequence covering the entire last glacial cycle (period between Terminations I and II) outcrops along the south-eastern coast of Formentera Island. A detailed geomorphological, geological and sedimentological study, supported by geochemical, soil and soil-morphology analyses, magnetic susceptibility, phytolite content and luminescence dating (TL, OSL) allowed to reconstruct the environmental evolution of this coastal setting, and to frame it within the evolutionary pattern of the North Atlantic climate variability. Three highstands of sea level are identified in this island for MIS 5e, and a fourth one is attributed to MIS5a. MIS5 – MIS4 transition is characterized by soil development under a moist-warm climate and a descending sea level scenario. Aeolian units (72 ± 7 ka BP) developed during MIS4 under prevailing northerly winds that persisted until the beginning of MIS3, when new aeolian dunes (54 ± 5 ka BP) developed after a major sea-level lowstand. A sudden shift in prevailing winds occur within MIS3, when aeolian units (51 ± 4 ka BP) grew under the influence of S-SW winds and moister climate, evidenced by a dense root bioturbation. The greater influence of northerly winds is attributed to the weakening of Atlantic Meridional Overturning Current (AMOC) in North Atlantic, and enhancement of westerlies in NW Europe during colder periods. Periods of prevailing southerly winds and moister climate correlate well with warm Greenland Interstadials, and reinforcement of AMOC. Between 50 and 40ka, alluvial/colluvial sedimentary units punctuated by soil and calcrete development, witness the climatic variability recorded along this period in the North Atlantic. A sedimentary hiatus with erosion and calcrete development characterizes the transit between MIS3 and MIS2. Finally, a reddish alluvial sedimentary unit records a short span of humid and warm climate (soil development, peak in magnetic susceptibility, phytolite content) within MIS 2 (20 ± 2 ka BP – 17 + 2.4/-2.2) that contrast with the general climatic trend recorded in Western Mediterranean during the Last Glacial Maximum.
Acrylamide-fat correlation in californian-style black olives using near-infrared spectroscopy
(MDPI, 2023-09-06) Montero Fernández, Ismael; Martín Tornero, Elísabet; Martín Vertedor, Daniel; Fernández Fernández, Antonio; Monago Maraña, Olga
Californian-style is one of the most important black table olive elaborations. During its processing, table olives produce acrylamide, a potential carcinogen compound generated during sterilization. In the present study, total fat and acrylamide content in Californian-style table olives were determined and a regression between them was performed (acrylamide concentration range: below limit of detection—2500 ng g−1 and 8–22% for total fat). Nowadays, there are fast and efficient new techniques, such as Near-Infrared Spectroscopy (NIRS) to measure fat content parameters. In that sense, NIRS was used to perform a fat content quantification model in olives in order to indirectly determine acrylamide content. Calibration models for fat quantification were obtained in defatted olive pastes from a unique variety and for olive pastes from different varieties. In the first case, best results were obtained since only one variety was used (R2 = 0.9694; RMSECV = 1.31%; and REP = 8.4%). However, in the second case, results were still acceptable R2 = 0.678, RMSECV = 2.3%, REP = 17.7% and RMSEV = 2.17%. Regression coefficients showed the most influence variables corresponded with fat. The determination coefficient for the fat and acrylamide correlation was high (r = 0.877), being an efficient approach to find out the contribution of fat degradation to acrylamide synthesis in table olives.
Active landscapes of Iberia
(Springer, 2020) Galve Arnedo , Jorge Pedro; Pérez Peña, José Vicente; Azañón, José Miguel; Insua Pereira, Diamantino M.; Cunha, Pedro P.; Pereira, Paulo; Viaplana Muzas, M.; Gracia Prieto, Francisco Javier; Remondo Tejerina, Juan; Jabaloy, Antonio; Bardají Azcárate, Teresa; Silva, Pablo G.; Zazo Cardeña, Caridad; Goy Goy, José Luis; Dabrio, Cristino José; Cabero, Ana; Ortuño Casanova, María del Rocío; Lario Gómez, Javier
The recent geodynamic evolution of Iberia is recorded in its topography. Geomorphic markers and their dating; morphometric indices estimated through cutting-edge DEM analysis techniques; and the link of all this data with results of geophysical studies allow discussing why Iberia displays the highest average elevation in Europe and shows a particular topography with such diversity of landscapes. For example, the region of the Iberian (or Hesperian) Massif, the western sector of Iberia, shows an anomalous average elevation without a satisfactory explanation. On the other hand, different explanations about the recent evolution of the Alpine mountain ranges of the eastern sector of Iberia have come to light after macroscale landscape analyses. This is strengthening the debate on the driving force behind the actual topography of the Pyrenees, Cantabrian Mountains, Iberian Chain and Betics.
An extreme wave event in eastern Yucatan, Mexico: Evidence of a palaeotsunami event during the Mayan times
(Wiley Online Library, 2020) Spencer, Chris; Bardají Azcárate, Teresa; Marchante Ortega, Ángel; Garduño Monroy, Victor Hugo; Macias, Jorge; Ortega, Sergio; Lario Gómez, Javier
The Yucatan Peninsula, Mexico, has typically been considered a tectonically stable region with little significant seismic activity. The region though, is one that is regularly affected by hurricanes. A detailed survey of ca 100 km of the eastern Yucatan and Cozumel coast identified the presence of ridges containing individual boulders measuring >1 m in length. The boulder ridges reach 5 m in height and their origin is associated with extreme wave event activity. Previously modelled tsunami waves from known seismically active zones in the region (Muertos Thrust Belt and South Caribbean Deformed Belt) are not of sufficient scale in the area of the Yucatan Peninsula to have produced the boulder ridges recorded in this study. The occurrence of hurricanes in this region is more common, but two of the most destructive (Hurricane Gilbert 1988 and Hurricane Wilma 2005) produced coastal waves too small to have created the ridges recorded here. In this paper, a new tsunami model with a source area located on the Motagua/Swan Island Fault System has been generated that indicates a tsunami event may have caused the extreme wave events that resulted in the deposition of the boulder ridges.
An optical sensor for the determination of digoxin in serum samples based on a molecularly imprinted polymer membrane.
(Elsevier, 2009-04) Durand Alegría, Jesús Senén; Paniagua González, Gema; Fernández Hernando, Pilar
This paper reports the synthesis and testing of a molecularly imprinted polymer membrane for digoxin analysis. Digoxin-specific bulk polymer was obtained by the UV initiated co-polymerisation of methacrylic acid and ethylene glycol dimethacrylate in acetonitrile as porogen. After extracting the template analyte, the ground polymer particles were mixed with plasticizer polyvinyl chloride to form a MIP membrane. A reference polymer membrane was prepared from the same mixture of monomers but with no template. The resultant membrane morphologies were examined by scanning electron microscopy. The imprinted membrane was tested as the recognition element in a digoxin-sensitive fluorescence sensor; sensor response was measured using standard solutions of digoxin at concentrations of up to 4 × 10−3 mg L−1. The detection limit was 3.17 × 10−5 mg L−1. Within- and between-day relative standard deviations RSD (n = 5) were in the range 4.5–5.5% and 5.5–6.5% respectively for 0 and 1 × 10−3 mg L−1 digoxin concentrations. A selectivity study showed that compounds of similar structure to digoxin did not significantly interfere with detection for interferent concentrations at 10, 30 and 100 times higher than the digoxin concentration. This simply manufactured MIP membrane showed good recognition characteristics, a high affinity for digoxin, and provided satisfactory results in analyses of this analyte in human serum.
Analysis of total arsenic content in purchased rice from Ecuador
(Czech Academy of Agricultural Sciences, 2019-12-31) Atiaga Franco, Oliva L.; Otero, Xose L.; Gallego Picó, Alejandrina; Escobar Castañeda, Luis A.; Carrera Villacrés, David; Bravo Yagüe, Juan Carlos
Natural and anthropogenic sources contribute to arsenic contamination in water and human food chain in Andean countries. Human exposure to arsenic via rice consumption is of great concern in countries where this crop is the dominant staple food, and limited information is available on the arsenic contamination on rice in Ecuador. This work was to contribute to the lack of knowledge analysing total arsenic by hydride generation-atomic absorption spectrometry in the samples of white, brown and parboiled rice purchased in Ecuadorian markets and produced in the two main rice wetlands in Ecuador, Guayas and Los Ríos, were carried out. For the samples from Guayas, arsenic concentration in white, brown and parboiled rice were 0.174 ± 0.014, 0.232 ± 0.021, and 0.186 ± 0.017 mg/kg respectively, whereas samples of white rice from Los Ríos showed a total arsenic level of 0.258 ± 0.037 mg/kg. This last arsenic concentration exceeds recommended maximum permissible limit by the FAO/WHO. Obtained data have available to estimate the Ecuadorian dietary exposure revealing serious health risk for population
Analysis of total arsenic content in purchased rice from Ecuador
(Czech Academy of Agricultural Sciences, 2019-12-31) Atiaga Franco, Oliva L.; Otero, Xose L.; Gallego Picó, Alejandrina; Escobar Castañeda, Luis A.; Carrera Villacrés, David; Bravo Yagüe, Juan Carlos
Natural and anthropogenic sources contribute to arsenic contamination in water and human food chain in Andean countries. Human exposure to arsenic via rice consumption is of great concern in countries where this crop is the dominant staple food, and limited information is available on the arsenic contamination on rice in Ecuador. This work was to contribute to the lack of knowledge analysing total arsenic by hydride generation-atomic absorption spectrometry in the samples of white, brown and parboiled rice purchased in Ecuadorian markets and produced in the two main rice wetlands in Ecuador, Guayas and Los Ríos, were carried out. For the samples from Guayas, arsenic concentration in white, brown and parboiled rice were 0.174 ± 0.014, 0.232 ± 0.021, and 0.186 ± 0.017 mg/kg respectively, whereas samples of white rice from Los Ríos showed a total arsenic level of 0.258 ± 0.037 mg/kg. This last arsenic concentration exceeds recommended maximum permissible limit by the FAO/WHO. Obtained data have available to estimate the Ecuadorian dietary exposure revealing serious health risk for population
Analytical technique and chemometrics approaches in authenticating and identifying adulteration of paprika powder using fingerprints: a review.
(Elsevier, 2022) Durán Merás, Isabel; Muñoz de la Peña, Arsenio; Galeano Díaz, Teresa; Monago Maraña, Olga
Paprika powder authentication has gained interest in recent decades along with increases in its consumption. There are different Protected Designation of Origins (PDOs) around the world, some of them are from Spain, and it is important to assure the quality parameters that they offer and to provide a guaranty about their quality and authentication. This review covers the latest advances concerning the targeted and untargeted methodologies. These methodologies have been developed to ensure paprika powder authenticity, corroborating that it belongs or not to a certain PDO and that it complies with the regulations and legal standards for its consumption, as well as detection of possible adulterations, mainly with Sudan dyes, which are illegal colorants. Differences between spectroscopic and non-spectroscopic methods have been emphasized. As observed from the literature, paprika powder has not been extensively studied, but the number of papers has been increasing in recent years.
Aportaciones científicas sobre geología del Cuaternario
(2024) Lario Gómez, Javier
Aportaciones científicas sobre geología del Cuaternario
(2024) Lario Gómez, Javier
Assessing matrix solid phase dispersion extraction strategies for determining bisphenols and phthalates in gilthead sea bream samples
(MDPI, 2024-01) Soliz Rojas, Dulce Lucy; Paniagua González, Gema; Bravo Yagüe, Juan Carlos; Fernández Hernando, Pilar; Garcinuño Martínez, Rosa Mª
Microplastics (MPs) and nanoplastics (NPs) are widely spread in the environment, generating significant concern due to their potential impact on environmental health. Marine species usually ingest plastic fragments, mistaking them for food. Many toxic compounds, such as plastic additives that are not chemically bound to the plastic matrix, can be released from MPs and NPs and reach humans via the food chain. This paper highlights the development and validation of a straightforward solid–liquid extraction clean-up procedure in combination with a matrix solid-phase dispersion method using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) detection, enabling facile, precise, and reliable identification and quantitation of a total of six bisphenols and phthalates in gilthead sea breams. Under the optimized conditions, the developed method showed good linearity (R2 > 0.993) for all target compounds. The recoveries obtained were between 70 and 92%. The relative standard deviations (RSDs) for reproducibility (inter-day) and repeatability (intra-day) were less than 9% and 10%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the target compounds ranged from 0.11 to 0.68 µg/kg and from 0.37 to 2.28 µg/kg, respectively. A new, efficient extraction methodology for the determination of BPA, BPS, BPF, DBP, DEP, and DHEP in gilthead seabream has been optimized and validated.
Assessing microplastic ingestion and occurrence of bisphenols and phthalates in bivalves, fish and holothurians from a Mediterranean marine protected area
(Elsevier, 2022-08-07) Rios Fuster, Beatriz; Alomar, Carme; Deudero, Salud; Paniagua González, Gema; Soliz Rojas, Dulce Lucy; Fernández Hernando, Pilar; Garcinuño Martínez, Rosa Mª
Microplastic (MP) ingestion, along with accumulated plasticizers such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and phthalates represented by diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP), were quantified in bivalves, fish, and holothurians collected from a coastal pristine area at the western Mediterranean Sea. MP ingestion in sediment-feeders holothurians (mean value 12.67 ± 7.31 MPs/individual) was statistically higher than ingestion in bivalves and fish (mean 4.83 ± 5.35 and 3 ± 4.44 MPs/individual, respectively). The main ingested polymers were polyethylene, polypropylene, and polystyrene. The levels of BPS, BPF, and DEHP were highest in bivalves' soft tissue; BPA and DBP had the highest levels in the holothurians’ muscle. In addition, the levels of all plasticizers assessed were lowest in fish muscle; only BPA levels in fish were higher than in bivalves, with intermediate values between those of bivalves and holothurians. This study provides data on exposure to MPs and plasticizers of different species inhabiting Cabrera Marine Protected Area (MPA) and highlights the differences in MP ingestion and levels of plasticizers between species with different ecological characteristics and feeding strategies.
Assessment of molecularly imprinted polymers as selective solid-phase extraction sorbents for the detection of cloxacillin in drinking and river water
(MDPI, 2023-11-03) Collado, Eduardo José; Paniagua González, Gema; Bravo Yagüe, Juan Carlos; Fernández Hernando, Pilar; Garcinuño Martínez, Rosa Mª
This paper describes a new methodology for carrying out quantitative extraction of cloxacillin from drinking and river water samples using a molecularly imprinted polymer (MIP) as a selective sorbent for solid-phase extraction (MISPE). Several polymers were synthesized via thermal polymerization using cloxacillin as a template, methacrylic acid (MAA) as a functional monomer, ethyleneglycoldimethacrylate (EGDMA) as a cross-linker and different solvents as porogens. Binding characteristics of the adequate molecularly imprinted and non-imprinted (NIP) polymers were evaluated via batch adsorption assays following the Langmuir and Freundlich isotherms and Scatchard assays. The parameters related to the extraction approach were studied to select the most appropriate polymer for cloxacillin determination. Using the optimized MIP as the SPE sorbent, a simple sample treatment methodology was combined with high-performance liquid chromatography (HPLC) to analyze cloxacillin residues in drinking and river water. Under the optimum experimental conditions, the MISPE methodology was validated using spiked samples. The linearity for cloxacillin was assessed within the limits of 0.05–1.5 g L􀀀1 and the recovery percentage was higher than 98% (RSD < 4%). The limits of detection and limits of quantification were 0.29 and 0.37 g L􀀀1 and 0.8 and 0.98 g L􀀀1 for drinking and river water, respectively. The selectivity of MIP against other ß-lactam antibiotics with similar structures (oxacillin, cefazoline, amoxicillin and penicillin V) was studied, obtaining a good recovery higher than 85% for all except cefazoline. The proposed MISPE-HPLC methodology was successfully applied for the detection of cloxacillin in drinking water from Canal de Isabel II (Madrid) and river water from the Manzanares River (Madrid).
Assessment of the impact of aquaculture facilities on transplanted mussels (Mytilus galloprovincialis): Integrating plasticizers and physiological analyses as a biomonitoring strategy
(Elsevier, 2022-02-15) Rios Fuster, Beatriz; Alomar, Carme; Capó, Xavier; Silva, Mónica; Solé, Montserrat; Freitas, Rosa; Deudero, Salud; Paniagua González, Gema; Soliz Rojas, Dulce Lucy; Fernández Hernando, Pilar; Garcinuño Martínez, Rosa Mª
The growing plastic production and its continuous use is a significant problem. In addition, aquaculture practices have experienced a considerable growth and plastic is widely used in these activities, hence plasticizers must be considered due to their potential ecotoxicological impacts on species. Mussels placed inside an Integrated Multi-Trophic Aquaculture (IMTA) system and at two control locations were employed to quantify the ingestion of anthropogenic particles and associated chemical plasticizers, such as bisphenol A (BPA) jointly to bisphenol F (BPF) and bisphenol S (BPS), and phthalates represented by diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP). In addition, some metabolism and oxidative stress related parameters were measured in mussels’ whole soft tissue. Anthropogenic particle ingestion of mussels increased over time at the three locations and the following order of abundance of pollutants was observed: BPA> BPF> DEHP> DBP> BPS> DEP. Even though no differences according to location were found for pollutants’ occurrence, time trends were evidenced for BPA and DEHP. On the other hand, a location effect was observed for biomarkers with highest values detected in mussels located at the vicinities of the aquaculture facility. In addition, a reduced detoxification activity was observed over time parallel to BPA decrease.
Cambios en la dinámica litoral y nivel del mar durante el Holoceno en el Sur de Iberia y Canarias Orientales
(Sociedad Geológica de España, 1996) Zazo Cardeña, Caridad; Dabrio, Cristino José; Goy Goy, José Luis; Bardají Azcárate, Teresa; Ghaleb, B.; Lario Gómez, Javier
The interaction between global factors tglobal" glacio-eustatic sea-leve/ rise) and regional factors (tectonic trend, oceanographic factor) is analyzed in different areas of the lberian and Canary lsland littora/. Sea-leve/ changes and climatic variations are stated for the Mediterranean and Atlantic littora/s, with different tidal ranges and tectonic trends. Different stages can be envisaged in the coastal evolution of a/most ali the analyzed areas from the beginning of Holocene (10.000 BP): at ca. 7.000 BP (Flandrian maximum) with a change from open estuaries to aggradational processes (Cádiz Gulf, subsiding area), basal peat (Valencia Gulf, subsiding area) and development of microcliffs (Mediterranean uplifting areas). From 7,000 to 2,700 BP a first progradation phase with development of spit bars took place in the mediterranean uplifting areas, whilst in the atlantic subsiding one starts the aggradation processes in the formerly open estuaries, an a/so from ca.4,000 BP development of spit-bar system. A second progradation phase ofthe spit bars systems occurs between 2,400 and 500 BP both in Almería and Cádiz Gulf, where a change from aggradation to progradation takes place in the estuary environments, and with a change in the direction of /ongshore drift (Mediterranean) and prevailing winds (both areas) at ca.2,400 BP. At ca. 1,200 BP a sudden paleogeographic change took place in estuary environments. From 500 BP up to now a marked increase of coastal progradation in ali littorals is observed. Climatic interpretations /ed to corre/ate anticyclonic conditions (as it happened during Little Ice Ages) with the growing of spit bar systems and progradation, while low pressure conditions (as during Medieval Warm Period) coincides with no progradation. In the Canary lslands, the development of storm ridges at ca. 3,500 BP can be corre/ated with an intensification of trade winds.
Cambios en la dinámica litoral y nivel del mar durante el Holoceno en el Sur de Iberia y Canarias Orientales
(Sociedad Geológica de España, 1996) Zazo Cardeña, Caridad; Dabrio, Cristino José; Goy Goy, José Luis; Bardají, T.; Ghaleb, B.; Lario Gómez, Javier
The interaction between global factors tglobal" glacio-eustatic sea-leve/ rise) and regional factors (tectonic trend, oceanographic factor) is analyzed in different areas of the lberian and Canary lsland littora/. Sea-leve/ changes and climatic variations are stated for the Mediterranean and Atlantic littora/s, with different tidal ranges and tectonic trends. Different stages can be envisaged in the coastal evolution of a/most ali the analyzed areas from the beginning of Holocene (10.000 BP): at ca. 7.000 BP (Flandrian maximum) with a change from open estuaries to aggradational processes (Cádiz Gulf, subsiding area), basal peat (Valencia Gulf, subsiding area) and development of microcliffs (Mediterranean uplifting areas). From 7,000 to 2,700 BP a first progradation phase with development of spit bars took place in the mediterranean uplifting areas, whilst in the atlantic subsiding one starts the aggradation processes in the formerly open estuaries, an a/so from ca.4,000 BP development of spit-bar system. A second progradation phase ofthe spit bars systems occurs between 2,400 and 500 BP both in Almería and Cádiz Gulf, where a change from aggradation to progradation takes place in the estuary environments, and with a change in the direction of /ongshore drift (Mediterranean) and prevailing winds (both areas) at ca.2,400 BP. At ca. 1,200 BP a sudden paleogeographic change took place in estuary environments. From 500 BP up to now a marked increase of coastal progradation in ali littorals is observed. Climatic interpretations /ed to corre/ate anticyclonic conditions (as it happened during Little Ice Ages) with the growing of spit bar systems and progradation, while low pressure conditions (as during Medieval Warm Period) coincides with no progradation. In the Canary lslands, the development of storm ridges at ca. 3,500 BP can be corre/ated with an intensification of trade winds.
Características del karst en hielo del glaciar Heim (Patagonia, Argentina). Predicción del drenaje subglaciar.
(ITGE-ETSIM, Madrid, 1990) Lario Gómez, Javier
Se presentan los resultados de la campaña realizada en el glaciar Heim, situado en la vertiente argentina del Hielo Continental Sur. la mayor masa glaciar del hemisferio austral después de la Antártida. En dicha campaña se realizo un reconocimiento de las formas kársticas desarrolladas en el glaciar y la localización de sumideros y cavidades para posteriores exploraciones. Se aplica el Método de prcdicci6n del drenaje subglaciar. basado en técnicas de análisis estructural.

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