ALBERT

Description: Transpressive deformation at the northern Caribbean plate boundary is accommodated mostly by two major strike-slip faults, but the amount and location of accommodation of the compressional component of deformation is still debated. We collected marine geophysical data including multi-beam bathymetry and multichannel seismic reflection profiles along this plate boundary around Hispaniola, in the Jamaica Passage and in the Gulf of Gonâve. The data set allows us to image the offshore active strike-slip faults as well as the compressional structures. We confirm that the Enriquillo-Plantain-Garden Fault Zone (EPGFZ) in the Jamaica Passage has a primary strike-slip motion, as indicated by active left-lateral strike-slip-related structures, i.e.: restraining bend, asymmetrical basin, en echelon pressures ridges and horsetail splay. Based on topographic cross-sections across the EPGFZ, we image a very limited compressional component, if any, for at least the western part of the Jamaica Passage. Toward the east of the Jamaica Passage, the fault trace becomes more complex and we identify adjacent compressional structures. In the Gulf of Gonâve, distributed folding and thrust faulting of the most recent sediments indicate active pervasive compressional tectonics. Estimates of shortening in the Jamaica Passage and in the Gulf of Gonâve indicate an increase of the compressional component of deformation towards the east, which nonetheless remains very small compared to that inferred from block modelling based on GPS measurements.

Description: The 290-km-long, Nayband strike-slip fault bounds the western margin of the Lut block and cuts across a region thought to have been quiescent during the last few millennia. Cl-36 cosmic ray exposure (CRE) and optically stimulated luminescence (OSL) dating of cumulative geomorphic offsets are used to derive the long-term slip rate. The measured offsets at two sites along the fault range between 9 ± 1 m and 195 ± 15 m with ages from 6.8 ± 0.6 ka to ∼ 100 ka, yielding minimum and maximum bounds of late Pleistocene and Holocene slip rates of 1.08 and 2.45 mm yr -1 , respectively. This moderate slip rate of 1.8 ± 0.7 mm yr -1 , averaged over several earthquake cycles, is compared to the paleoseismic record retrieved from the first trench excavated across the fault. Combining the paleoseismic evidence with 18 OSL ages obtained from this trench site demonstrates the occurrence of at least four large (M w  ∼ 7) earthquakes during the last 17.4 ± 1.3 ka and of two older earthquakes, one before ∼ 23 ka and another before 70 ± 5 ka. The exposed sediment succession also indicates a significant gap at the end of MIS-2 and the beginning of MIS-1. The age of the most recent regional incision is accurately bracketed between 6.1 ka and 7.4 ka. Sediments from the last ∼ 7 ka contain evidence of the three younger earthquakes. Interestingly, the penultimate and antepenultimate events occurred between 6.5 ± 0.4 ka and 6.7 ± 0.4 ka within a time interval lasting at most 1 ka whereas the most recent earthquake occurred within the last millennium. Such an irregular earthquake occurrence suggests the seismic behavior of the Nayband fault is not strictly time dependent but possibly related to clustering. From this and taking into account the occurrence of the most recent earthquake within the last 800 years, the imminence of an earthquake along the Nayband fault cannot be discarded. Although the most recent surface-rupturing event seems to have occurred after AD 1200, this event went unnoticed in the historical records. This provides a marked illustration of the incompleteness of the historical seismic catalogs in Central Iran, challenging any assessment of regional seismic hazard without appropriate geologic and geochronological information. Large and infrequent earthquakes are characteristic of the seismic behavior of the slow-slipping strike-slip faults slicing Central and Eastern Iran. Also, the slip rates summed across Central and Eastern Iran from the Iran Plateau up to the Afghan lowlands appear in agreement with the most recent GPS data.

Description: The investigation focuses on the analysis of dissolved sulfonamides, tetracyclines, analgesics, anticonvulsants and hormones in surface water. Runoff event and baseflow samples were analyzed in two small river catchments of different landuse in Luxembourg. For most of the flood events similar pollutant loads to those transported during one day with average baseflow discharge were observed. The maximum contents during flood events and the Event Mean Concentrations are controlled by pre-event hydro-climatological conditions. For all substances under investigation maximum concentrations and Event Mean Concentrations show a decrease with raising antecedent rainfall. In addition, the inter-storm and intra-storm variability of the pollutant transport were determined. Runoff generation and corresponding transport of xenobiotic compounds show a complex pattern with many interrelated processes, taking place within bedrock, soil, anthropogenic facilities, the channel, and in different parts of the basins under investigation. Different sources of pollutants can be identified and related to particular locations in the basin. The influence of the sewer systems is obvious. In the agricultural Mess basin higher rainfall amounts lead to greater quantities of laterally inflowing soil water with higher concentrations of dissolved oxytetracycline. This originates from veterinary medicines administered to livestock and enters the environment through the application of organic fertilizers, especially by slurry that is applied to the fields. Copyright © 2012 John Wiley & Sons, Ltd.

Description: In addition to osteoblast lineage cells, the TNF-like factor Receptor Activator of NF-ΚB ligand (RANKL) is expressed in both B and T cells and may play a role in bone resorption. Rankl expression in mouse T cells is mediated through multiple distal elements marked by increased transcription factor occupancy, histone tail acetylation and RNA polymerase II recruitment. Little is known, however, of the regulation of human RANKL in T cells. Accordingly, we examined the consequence of T cell receptor (TCR) activation on expression of this factor in both Jurkat cells and in primary human T cells. We then explored the mechanism of this regulation by scanning over 400 kb of DNA surrounding the RANKL locus for regulatory enhancers using ChIP-chip analysis. Histone H3/H4 acetylation enrichment identified putative regulatory regions located between -170 and -220 kb upstream of the human RANKL TSS that we designated the human T cell control region (hTCCR). This region showed high sequence conservation with the mouse TCCR. Inhibition of MEK1/2 by U0126 resulted in decreased RANKL expression suggesting that stimulation through MEK1/2 was a prerequisite. ChIP-chip analysis also revealed that c-FOS was recruited to the hTCCR as well. Importantly, both the human RLD5a/b enhancer and segments of the hTCCR mediated robust inducible reporter activity following TCR activation. Finally, SNPs implicated in diseases characterized by dysregulated BMD co-localized to the hTCCR region. We conclude that the hTCCR region contains a cell-selective set of enhancers that plays an integral role in the transcriptional regulation of the TNFSF11 gene in human T cells. J. Cell. Biochem. © 2014 Wiley Periodicals, Inc.

Description: The Earth Magnetic Anomaly Grid at 2-arc-minute resolution version 3, EMAG2v3, combines marine and airborne trackline observations, satellite data, and magnetic observatory data to map the location, intensity, and extent of lithospheric magnetic anomalies. EMAG2v3 includes over 50 million new data points added to NCEI's Geophysical Database System (GEODAS) in recent years. The new grid relies only on observed data, and does not utilize a priori geologic structure or ocean age information. Comparing this grid to other global magnetic anomaly compilations (e.g., EMAG2 and WDMAM) we can see that the inclusion of a priori ocean-age patterns forces an artificial linear pattern to the grid; the data-only approach allows for greater complexity in representing the evolution along oceanic spreading ridges and continental margins. EMAG2v3 also makes use of the satellite-derived lithospheric field model MF7 in order to accurately represent anomalies with wavelengths greater than 300 km and to create smooth grid merging boundaries. The heterogeneous distribution of errors in the observations used in compiling the EMAG2v3 was explored, and is reported in the final distributed grid. This grid is delivered at both 4km continuous altitude above WGS84, as well as at sea level for all oceanic and coastal regions.

Description: The Iranian plateau is a vast inland region with a smooth average elevation of c. 1.5 km formed at the rear of the Zagros orogen as a result of the Arabia-Eurasia collision (i.e., over the last 30-35 My). This collision zone is of particular interest due to its disputed resemblance to the faster Himalayan collision, which gave birth to the Tibetan plateau around 50 Myrs ago. Recent studies have suggested that a recent (10-5 Ma) slab break-off event below Central Iran caused the formation of the Iranian plateau. Here, we test several hypotheses through large-scale (3082×590 km) numerical models of continental subduction models incorporate a free upper surface erosion, rheological stratification, brittle-elastic-ductile rheologies, metamorphic phase changes (density and physical properties) and account for the specific crustal and thermal structure of the Arabian and Iranian continental lithospheres. We test the impact of the transition from oceanic to continental subduction and the topographic consequences of the progressive slowdown of the convergence rate during continental subduction. Our results demonstrate the role of mantle flow beneath the overriding plate, initiated as an indirect consequence of slab break-off. This flow creates a dynamic topography support during continental subduction and results in delamination of the overriding plate lithospheric mantle followed by isostatic readjustment, hence of further uplift and maintenance of a plateau-like topography without significant crustal thickening. The slow-down of the convergence rate during the development of the continental subduction/collision phase largely contributes to this process by controlling the timing and depth of slab break-off.

Description: Antarctic pack ice serves as habitat for microalgae which contribute to Southern Ocean primary production and serve as important food source for pelagic herbivores. Ice algal biomass is highly patchy, and remains severely undersampled by classical methods such as spatially restricted ice-coring surveys. Here we provide an unprecedented view of ice algal biomass distribution, mapped (as chlorophyll- a ) in a 100m-by-100m area of a Weddell Sea pack-ice floe, using under-ice irradiance measurements taken with an instrumented Remotely Operated Vehicle. We identified significant correlations (p 〈 0.001) between algal biomass and concomitant in situ surface measurements of snow depth, ice thickness and estimated sea-ice freeboard levels using a statistical model. The model's explanatory power (r 2 = 0.30) indicates that these parameters alone may provide a first basis for spatial prediction of ice algal biomass, but parameterisation of additional determinants is needed to inform more robust upscaling efforts.