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We examined the status of the first metacarpal bone whose shape, fetal and post-natal development correspond to those of the thumb proximal phalanx. Galen already described this, circa 170 CE. Our radiographic data confirm that the pre-axial (radial or anterior) side of the hand matures, later than the post-axial (ulnar or posterior) side, both, pre- and post-natally. A new perspective on thumb primate and human ontogeny is discussed and comparative observations on the Evolutionary Development (EvoDevo) of the thumb and the first toe are proposed along with a nomenclature honoring Galen's original proposition. Se analiza el estado del primer metacarpiano cuya forma y desarrollo embrionario, fetal y postnatal corresponde a los de la primera falange del pulgar. Galeno notó que éste era la primera falange del pulgar cerca de 170 DC. Esto no es un simple cambio de nomenclatura, ya que da una nueva luz a los problemas evolutivos de ontogenia (EvoDevo). Nuestros datos radiográficos confirman que el lado radial (anterior o pre-axial) de la mano madura, pre y post-natalmente, mas tardíamente que el lado cubital (posterior o post-axial). Se discuten nuevas perspectivas sobre la ontogenia y filogenia humana y de primates, y se proponen estudios comparativos del desarrollo del pulgar y del ortejo mayor.

This study is among the first to examine the genesis of the seafloor and subsurface undulations on the Adriatic continental shelf by integrating stratigraphic information and in situ and laboratory geotechnical measurements. Interpretation of sediment behavior is based on a 32-m-long borehole crossing ( 1) a possible shear plane and ( 2) a silty clay layer at about 20 m below seafloor (mbsf) on which sediment undulations are rooted and could be interpreted as a potential weak layer succession. Our main results in terms of triggering mechanism for the observed undulations show that under an earthquake, liquefaction and/or failure of the silty-clay sediments ( weak layer) leading to deformation of the upper more cohesive sediments is possible only when such a layer is buried by less than 5 m. For greater burial thicknesses, this silty clay becomes stable under the confining lithostatic pressure exerted by the overlying sediment. This work shows that the seafloor and subsurface undulations observed in the study area are most probably the result of an early deformation process of the seafloor followed by a depositional process.

This study is among the first to examine the genesis of the seafloor and subsurface undulations on the Adriatic continental shelf by integrating stratigraphic information and in situ and laboratory geotechnical measurements. Interpretation of sediment behavior is based on a 32-m-long borehole crossing (1) a possible shear plane and (2) a silty clay layer at about 20 m below seafloor (mbsf) on which sediment undulations are rooted and could be interpreted as a potential weak layer succession. Our main results in terms of triggering mechanism for the observed undulations show that under an earthquake, liquefaction and/or failure of the silty-clay sediments (weak layer) leading to deformation of the upper more cohesive sediments is possible only when such a layer is buried by less than 5 m. For greater burial thicknesses, this silty clay becomes stable under the confining lithostatic pressure exerted by the overlying sediment. This work shows that the seafloor and subsurface undulations observed in the study area are most probably the result of an early deformation process of the seafloor followed by a depositional process.

BackgroundThe world merchant fleet comprise about 1.4 million seafarers. Multi ethnic crews make about 2/3 of the world merchant fleet. The purpose was to descripe important aspects of the working environment for seafarers. MethodThe seafarers have biannual health examinations and they used 5-10 minutes during the waiting time to complete a small, anonymous questionnaire with questions concerning the latest tour of duty. Data were collected in 11 countries: Denmark (DK), the Philippines, Croatia, Spain, South Africa, Ukraine, Russia, United Kingdom United Kingdom (UK), Poland, Indonesia and China. The questionnaire was on safety on board: (self-perceived safety, knowledge of safety representative, exposure to chemical substances and the use of personal safety equipment against chemical exposures). Injuries during the latest tour of duty were examined. Results6.593 questionnaires were collected in 2001. The participation rate was 90-95%. The length of the latest tour differed significantly for the nationalities: The Philippines, Indonesian, Chinese and Ukraine ratings stayed at sea for an average of 8 to 11 months while the ratings from the Western countries, like DK and the UK had 2,5 to 3,5 months at sea. The average was 60-80 working hours a week. 60% had 70 hours or more per week and one third more than 80 hours. 80 % worked all the 7 days in the week. Officers were 15-30% among the Philippines and Indonesian seafarers and 80% among the seafarers from United Kingdom and Denmark. 80% of the seafarers from the UK and DK worked on ships from their own nation while the Philippines and the Indonesian seafarers mainly worked on foreign ships. Seafarers over 50 years of age were few among the eastern nationalities. Nearly 9% of the seafarers were injured on the latest tour of duty. Slips, trips and falls were frequent involved. Seafarers from the Philippines and Indonesia had low incidence rates of injury. The self-perceived health was generally good among the seafarers, with some national exceptions Conclusions- Remarkable non-equity for work conditions between the nationalities- Working hours per week and the stay on board are very long for some nationalities- Nearly 9% of the seafarers were injured on the latest tour of duty- Slips trips and falls constitute about half of the most serious injuries.

The Barcelona continental shelf is part of a 6–20 km wide canyon-bounded shelf located off the city of Barcelona (NE Spain). This study integrates newly acquired high-resolution single channel seismic reflection profiles and available lithological information of the Barcelona shelf to describe its late Quaternary architecture and the role of global glacio-eustatic fluctuations and local factors in its development. Four major sequence boundaries are identified throughout the seismic dataset. They are tentatively correlated with the four last 4th order (100–120 ka) high-amplitude late Quaternary glacio-eustatic lowstands. Most of the stratigraphic record is formed by falling stage systems tracts with forced-regressive deposits, which confers a general progradational vertical stacking pattern. Transgressive systems tracts are represented by continuous units confined directly off river sources and on previously eroded surfaces. Stillstand deposits are difficult to recognize in the available dataset. The uppermost seismic unit corresponds to the Holocene shore-parallel Besos and Llobregat joint prodelta affected by the prevailing south-westward circulation.

Hematological parameters of birds and mammals seem to respond to environmental requirements, such as hypoxia at high altitude and the energetic demands of locomotion and flight. In this work we hypothesize that lung capillary hematocrit and red blood size may be influenced by the energetic requirements of flight. Also, we propose that hematological parameters should vary together with the morphological parameters that determine oxygen diffusion capacity. We analyzed the red blood cell size and the local characteristics of the pulmonary capillary hematocrit correlating these with the pulmonary factors that determines the oxygen diffusion capacity. We deal with seven species, non-flying and flying birds and mammals, with different energetic requirements. The capillary hematocrit was not different in each taxon, but the red blood cell size was smaller in flying mammals and birds than non-flying ones. Correlation of erythrocyte size with the diffusing characteristics of the lungs produced a non-phylogenetic clustering with a group constituting by the bats Tadarida brasiliensis y Myotis chiloensis, and the bird Z. auriculata; revealing similar functional response in unrelated species. Finally, in mammals, a negative correlation between the red blood cell size and the mass-specific oxygen diffusion capacity was obtained. These results suggest that the direction of the hematological and pulmonary adjustments is governed mainly by the requirements of flight independent of phylogenetic origin of the species studied Los parámetros hematológicos y pulmonares parecen responder a las exigencias ambientales como la hipoxia y la alta altitud y a los requerimientos energéticos de la locomoción. En este trabajo sometemos a prueba la hipótesis que el hematocrito del capilar pulmonar y el tamaño del glóbulo rojo pueden ser influidos por los requerimientos energéticos del vuelo. También proponemos que los parámetros hematológicos varían en conjunto con los parámetros que determinan la capacidad de difusión de oxígeno. Analizamos el tamaño del glóbulo rojo y las características locales del hematocrito capilar pulmonar correlacionándolos con los factores pulmonares que afectan la capacidad de difusión de oxígeno. Analizamos siete especies de diferente requerimiento energético, corredoras y voladoras. El hematocrito capilar pulmonar no mostró diferencias significativas en aves ni en mamíferos. El tamaño del glóbulo rojo fue menor en los mamíferos y en aves voladoras con respecto a sus pares no voladores. La respuesta conjunta del glóbulo rojo, la superficie respiratoria y la membrana alvéolo-capilar mostró un agrupamiento no filogenético donde se destaca un cluster constituido por mamíferos y aves de vuelo activo (dos murciélagos: Tadarida brasiliensis y Myotis chiloensis y la tórtola Zenaida auriculata). Finalmente, en mamíferos se obtiene una relación inversa entre la capacidad de difusión de oxígeno y el tamaño del glóbulo rojo. En definitiva, los hallazgos sugieren la existencia de ajustes funcionales hematológicos y pulmonares como una respuesta conjunta a las exigencias del vuelo, independientes de su origen filogenético

Udgivelsesdato: Juni

The detailed analysis of the International Marine Past Global Changes Study core MD99-2343 recovered from a sediment drift at 2391 m water depth north of the island of Minorca illustrates the effects of climate variability on thermohaline circulation in the western Mediterranean during the last 12 kyr. Geochemical ratios associated with terrigenous input resulted in the identification of four phases representing different climatic and deepwater overturning conditions in the Western Mediterranean Basin during the Holocene. Superimposed on the general trend, eight centennial- to millennial-scale abrupt events appear consistently in both grain size and geochemical records, which supports the occurrence of episodes of deepwater overturning reinforcement in the Western Mediterranean Basin. The observed periodicity for these abrupt events is in agreement with the previously defined Holocene cooling events of the North Atlantic region, thus supporting a strong Atlantic-Mediterranean climatic link at high-frequency time intervals during the last 12 kyr. The rapid response of the Mediterranean thermohaline circulation to climate change in the North Atlantic stresses the importance of atmospheric teleconnections in transferring climate variability from high latitudes to midlatitudes.

With the aim of improving the knowledge of the open ocean carbon cycle, we present a budget of particulate organic carbon (POC) fluxes carried out in the deep central part of the Algero-Balearic Basin (ABB) at 2850 m water depth based on a single mooring equipped with five automated sediment traps deployed from April 2001 to May 2002 at depths of 250, 845, 1440, 2145 and 2820 m. Suspended particulate matter (SPM) and superficial sediments were also used as indicators of hydrodynamics and carbon burial, respectively. The data reveal that the fraction of primary production buried in the sediment, which finally leads to the sequestration of carbon dioxide from the atmosphere, is 0.16%, lower than the values found in the nearby continental margin regions such as the Alboran Sea (0.48–0.89%) but of the same order as recorded at other Mediterranean sites at similar depths, such as the Ionian Sea (0.11%). As they sink through the water column, the particles exhibit decreases in flux that are similar to those observed elsewhere, but also show variations that appear to correlate with hydrological features of the water masses present in the basin, as revealed by SPM concentrations and compositions. The input of the tyrrhenian deep water (TDW) into the ABB at 800–1500 m of water depth exhibits low suspended POC concentrations and low sinking POC fluxes were also observed in this depth range. Gulf of Lions water mass formation appears to also contribute to elevated suspended POC concentrations and perhaps POC accumulation in the traps and sediments by spreading of dense cold water along the whole ABB that supplied POC at depths higher than 2000 m.

The anthropogenic affectation was evaluated on the coast N of the Gulf of Batabanó in May 2003 (corresponding to the provinces of Matanzas and Havana), in areas located in the line of the coast. The results were compared with the historical information of the sector. In the coast N and the Ensenada of the Broa, the parameters oxygen saturation, DBO5 and DQO showed characteristic high values of eutrofication. The biggest contribution in the Cianoficies was in the near coastal areas to sources of organic contamination. In the case of the nutrients they show specific data of mesothrofic waters with tendency to the eutrofization and the silts presented a high affectation for toxic metals. The area near to Guanímar is distinguished to present conditions of organic contamination that favor heterothrofic conditions, corroborated by a prevalence of the processes of mineralization of the organic matter over primary production and lows values of fitoplankton concentration. On the contrary, in the region of Surgidero of Batabanó, the processes of synthesis of organic matter prevail suggested by a high primary production, and concentration of fitoplankton, with low breathing levels and mineralization of the organic matter, that indicates that the system is behaving autothrofically. In a general way, this sector is very affected by the anthropogenic impact. The information obtained is of great importance for the development of the fishing and tourist industries in the area. Published

The PROMESS1 PRAD2 site includes two continuous sediment cores (boreholes PRAD2-4 for stratigraphy and PRAD2-5 for geotechnical studies), in situ cone penetration measurements (CPTU; boreholes PRAD2-3 and PRAD2-6) and spectral gamma ray downhole logging (borehole PRAD2-4) of a stratigraphic succession on the western flank of the Adriatic continental shelf in 56 m water depth. The sedimentary succession is composed mainly of marine silty clay (0 to 27 mbsf) and alternating fine sand and clay (27 to 32 mbsf). The upper 20 m of sediment show seafloor and subsurface undulations on reflection-seismic profiles, representing sediment deformation features with limited displacement, muddy bedforms or a combination, and whose interpretation justified a set of geotechnical measurements. The chronology of the sedimentary succession is based on a regional correlation to stratigraphic units identified on reflection-seismic profiles that were dated in other sediment cores with ecobiostratigraphy of planktic and benthic foraminifera, magnetic parameters (including secular variations in inclination and declination of the Earth magnetic field), oxygen isotope stratigraphy, radiocarbon dating, palynology and tephrochronology. The sedimentary record of the borehole represents the deposit of the last sea level highstand (HST, aged 5.5 kyr to present) and part of the previous transgression. Seismic correlation indicates that: 1) the sandy layers at the base correspond to a progradational unit emplaced during the Bolling/Allerod and Younger Dryas periods culminating in a sharp submarine erosional surface at 27 mbsf; 2) the maximum flood surface (mfs) at the base of the HST is at ca. 21 mbsf; 3) above the mfs there is a seismic unit characterized by discontinuous seismic reflectors at the top, marking a condensed interval between approximately 5.5 and 3.7 kyr; above this condensed unit undulations are present. We show here the result of the direct analysis of the sedimentary succession using integrated stratigraphic techniques and in-situ and laboratory geotechnical tests. Due to the shallow depth of PRAD2 site, we used benthic ecozones to identify the position of the mfs. In particular we noted that from 21 mbsf upwards the benthic association is abundant with frequent E. granosum and B. ex gr. marginata, some V. complanata and C. laevigata carinata, while plankton is rare and composed by G. ruber, G. sacculifer, Orbulina, and G. aequilateralis. Below 21 mbsf, the presence of benthic species U. peregrina, G. laevigatus, and H. balthica suggests a relatively deeper setting, that corresponds to the peak marine ingression at the base of the HST. In-situ measurements and geotechnical tests confirm the existence at 20.5 mbsf of a 1-m thick silty clay layer immediately above the mfs, coarser than the surrounding sediment. This level resulted the most sensitive to earthquake loading in triaxial cyclic tests. Calculation of the potential liquefaction of sediment from PRAD2 site under an earthquake shaking (comparable in magnitude with those measured in this area) shows that sediment liquefaction of the silty clay level above the mfs was possible when its burying was less than 5 m. (Work supported by contract EC EVR1-2001-00041

The results presented in this paper show that adenosine A2A receptor (A2AR) form homodimers and that homodimers but not monomers are the functional species at the cell surface. Fluorescence resonance energy transfer (FRET) and bioluminescence resonance energy transfer (BRET) techniques have been used to demonstrate in transfected HEK293 cells homodimerization of A2AR, which are heptaspanning membrane receptors with enriched expression in striatum. The existence of homodimers at the cell surface was demonstrated by time-resolved FRET. Although agonist activation of the receptor leads to the formation of receptor clusters, it did not affect the degree of A2AR-A2AR dimerization. Both monomers and dimers were detected by immunoblotting in cell extracts. However, cell surface biotinylation of proteins has made evident that more than 90% of the cell surface receptor is in its dimeric form. Thus, it seems that homodimers are the functional form of the receptor present on the plasma membrane. A deletion mutant version of the A2A receptor, lacking its C-terminal domain, was also able to form both monomeric and dimeric species when cell extracts from transfected cells were analyzed by immunoblotting. This suggests that the C-terminal tail does not participate in the dimerization. This is relevant as the C-terminal tail of A2AR is involved in heteromers formed by A2AR and dopamine D2 receptors. BRET ratios corresponding to A2AR-A2AR homodimers were higher than those encountered for heterodimers formed by A2AR and dopamine D2 receptors. As A2AR and dopamine D2 receptors do indeed interact, these results indicate that A2AR homodimers are the functional species at the cell surface and that they coexist with A2AR/D2 receptor heterodimers.

This paper presents an overview of the geological, biological and oceanographical environment of coral banks in the Porcupine Seabight. The study area is characterised by well delimited geographic clusters of coral banks, each characterized by their typical bank morphology and environmental setting. In the central part two mound provinces are recognised: complex flat topped seafloor mounds in the 'Hovland mound province', and a large number of smaller N-S elongated buried mounds in the 'Magellan mound province'. Along the eastern margin of the basin partly buried and outcropping mounds form the 'Belgica mound province'. The banks are mound-shaped elevations, hosting living deepwater coral (Lophelia sp., Madrepora sp., Desmophyllum sp., Dendrophylla sp.) and associated fauna. This biological active layer covers a dead assemblage of corals clogged with mud. Endogenic and exogenic environmental parameters are evaluated in time and related to the geomorphological response of the banks. All coral banks, buried or outcropping, occur in association with current-induced features (e.g., scouring features, dunes) and steep palaeo and present seabed slopes. Only a few banks are outcropping in the present setting which suggests that environmental conditions were more favourable for bank development in the past. The depth range of these outcropping mounds coincides with the top of the dense Mediterranean OutflowWater, where current enhancement may control the coral distribution not only nowadays but also in the initial phase of coral bank development. The distribution of corals in the southeastern North Atlantic and the actual link with Mediterranean water suggest a possible migration of corals within the Mediterranean water into the Atlantic. The startup phase of coral bank development in Porcupine Seabight was simultaneous for all provinces, after a Late Pliocene period of erosion and non-deposition. Sediment stress time variations, largely controlled by currents, play an important role in bank development. Coral banks accrete by active baffling of sediment by the biological framework and extension of the biological cap (catch-up phase). Once this fragile system between sedimentation and biological growth is out of balance, the framework will progressively be clogged with sediment (keep-up phase). Once sediment dominates the structure the coral banks get buried and draped by sediment (give-up phase).

La vía aérea ha sido propuesta como modelo de diseño óptimo desde una perspectiva física. Su diseño se ha asociado con un adecuado flujo de gases a los alvéolos, una mínima producción de entropía y un mínimo costo en materia y energía. Se ha propuesto un decrecimiento exponencial del diámetro de los bronquios (dG) en función de la generación: dG = do·2-G/3, asociado a una mínima producción de entropía. También se ha propuesto un modelo de renormalización: dG = An·G-u donde u es un exponente y An una función que introduce desviaciones periódicas en la escala, es decir más de una escala, evitando la propagación distal de errores aleatorios en el calibre de un bronquio. Sin embargo, este último resultado podría ser consecuencia en árboles asimétricos de la relación entre el diámetro y el orden del bronquio y no de la generación. En este trabajo estudiamos la asimetría y el decrecimiento del diámetro bronquial en dos especies. Se utiliza el modelo de Zamir como un sistema externo de medida de la optimización. Encontramos una clara asimetría del árbol bronquial. Comprobamos que la relación exponencial diámetro-orden es siempre muy buena (R² ³ 0,8) y que en cambio la relación exponencial diámetro-generación es menos clara (R² < 0,6). La supuesta modulación armónica desaparece al considerar el orden y no la generación. Se determina un alto grado de optimización de la estructura en las dos especies From a physical perspective, the air way has been proposed as a model of optimal design. Its design has been associated with a optimal gases flow to the alveoli, a minimum entropy production and minimal costs of mass and energy. The decrease of the bronchial diameter (dG) along the airway has been modeled by (i) an exponential decay of the bronchial diameter (dG) as function of its generation: dG = do·2-G/3, associated to a minimum entropy production, and (ii) a renormalization model: dG = An·G-u where u is an exponent and An an harmonic function which introduces periodic variations in the scale, buffering the propagation of stochastic errors in the bronchial diameter. However, that the last result in asymmetric trees may be a consequence of a real relationship between diameter and order more than a relationship diameter-generation. In this work we explore this hypothesis in two species. We also use the Zamir model for vascular trees as an out method to explore the optimality degree of the bronchial ramification. We found a clear asymmetry of the analyzed bronchial trees. We shown that the relationship diameter-order is always very good (R² ³ 0,8). In contrast, the determination coefficients for the relationship diameter-generation were lower (R² < 0,6). The proposed harmonic modulation vanishes when changing generation by order. There were a high optimality degree of the bronchial junctions

Numerous studies illustrate that high-latitude, ice-sheetdominated, continental margins are more prone to largescale mass-movements than lower-latitude margins. Major slope instabilities are well-documented along the northern hemisphere, glacial margins of the Norwegian Sea (e.g.Storegga Slide) and the Svalbard-Barents Sea and of Greenland and eastern Canada. However, similar slopeinstabilities along the Antarctic Margins seem to be much more scarce. Here, we present the first detailed analysis of a Late Quaternary slide along an Antarctic margin.The Gebra Slide is situated along the Trinity Peninsula margin in the Central Bransfield Basin, Antarctic Peninsula. The slide scarp, clearly revealed by multibeam bathymetric data, extends over a length of about 30 km, from 1500 to 2000 m of water depth on the lower slope, well below the slope break which is here at about 750 m. The head of the slide is formed by an amphitheatre-shaped set of scarps with an elevation of 100 m. Further upslope, but still detached from the slope break, a second less-developed set of scarps suggests a multi-stage retrogressive mass-wasting process. The slide scarp area covers about 230 km2.Seismic reflection (airgun) profiles show that the associated deposit covers about 315 km2 of the western King George basin. Its typical acoustically transparent to chaotic seismic facies suggests it is essentially a debris flow deposit. The deposit is draped by the recentmost hemipelagic sedimentary unit. According to seismic-stratigraphic correlations, we put the age of the main sliding event at about 13.500 a B.P., around the last deglaciation in this part of the Antarctic (Banfield et al., 1995). The volume of this debris flow (21 km3) agrees very well with the disappeared volume higher on the slope.Although the Gebra Slide is positioned in front of a glacial trough with a higher sedimentary input, the sedimentation rates during both the present interglacial and the last glacial maximum - estimated as 0.24 cm/yr and 3.4 cm/yr, respectively, based on sediment cores and seismic stratigraphy - are too low for significant build-ups of excess pore pressure to develop in the sedimentary column. The position of the main scarp on water depths of 1500 m is far below the maximum grounding depth of the Antarctic Peninsula ice sheet (about 1000 m), excluding a possible triggering by loading/unloading of an advancing/retreating ice cap as a possible cause. No deep faulting in the underlying basement is observed on the seismic profiles, which also rules out a purely tectonic control. On the other hand, triggering by an earthquake in the volcanically and seismically active Bransfield Basin should not be excluded. Therefore, we propose that only an interaction between all above processes - in space and time - could have lead to the triggering of the Gebra Slide.