ALBERT

Description: On May 4, 1910, the most destructive earthquake in the history of Costa Rica (Ms 6.4) destroyed the city of Cartago, a major city located in the Valle Central of Costa Rica. Using both paleoseismological and morphotectonic analyses we have found evidence that points to the Aguacaliente Fault as the source of this earthquake. This structure is a N100 o E trending, strike-slip fault situated to the south of Cartago and within a wide band of deformation. We excavated two trenches near Bermejo, south of Cartago. We found evidence of three surface ruptures within the last 1,000 years on this fault. The age of the most recent rupture is consistent with the Cartago 1910 earthquake. The Aguacaliente fault is a seismogenic source capable of producing large earthquakes (Mw 6.5-6.9) with an estimated recurrence interval of about 500 years. © 2013 Blackwell Publishing Ltd

Description: ABSTRACT Using station data from the United States Historical Climatology Network, we preformed a running trend analysis of temperature, precipitation and drought in the Alabama–Coosa–Tallapoosa and Apalachicola–Chattahoochee–Flint river basins for the time period 1895–2012 on annual and monthly timescales. Our study found that long-term precipitation and temperature trends were statistically detectible but relatively slight in the order of an increase at 3 mm per decade for precipitation and a decline of 0.02 °C per decade for temperature. Running trend analyses for the time period 1895–2012 found field-significant and relatively large annual precipitation increases and temperature decreases between the 1950s and early 1980s associated with the 'warming hole'. The magnitude of precipitation trends for the aforementioned period was in the range of 7 mm per year for precipitation and 0.6 °C per decade for temperature. For temperature, we observed generally decreasing maximum, minimum and mean temperatures in the 1960s and 1970s and increasing temperatures from the 1970s to present. Minimum temperatures particularly showed a strong increase in recent summer months in the range of 0.3 °C per decade. Trends in the diurnal temperature range showed a recent narrowing during summer and fall months. Differences in the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) did not show a strong effect of temperature on drought for this region.

Description: The staurolite–biotite–garnet–cordierite–andalusite–plagioclase–muscovite–quartz metapelitic mineral assemblage has been frequently interpreted in the literature as a result of superimposition of various metamorphic events, for example, in polymetamorphic sequences. The assemblage was identified in schists from the Ancasti metamorphic complex (Sierras Pampeanas of Argentina) where previous authors have favoured the polymetamorphic genetic interpretation. A pseudosection in the MnNCKFMASH system for the analysed XRF bulk composition predicts the stability of the sub-assemblage staurolite–biotite–garnet–plagioclase–muscovite–quartz, and the compositional isopleths also agree with measured mineral compositions. Nevertheless, the XRF pseudosection does not predict any field with staurolite, andalusite and cordierite being stable together. As a result of more detailed modelling making use of the effective bulk composition concept, our interpretation is that the staurolite–biotite–garnet–plagioclase–muscovite–quartz sub-assemblage was present at peak metamorphic conditions, 590 °C and 5.2 kbar, but that andalusite and cordierite grew later along a continuous P–T path. These minerals are not in mutual contact and are observed in separate microstructural domains with different proportions of staurolite. These domains are explained as a result of local reaction equilibrium subsystems developed during decompression and influenced by the previous peak crystal size and local modal distribution of staurolite porphyroblasts that have remained metastable. Thus, andalusite and cordierite grew synchronously, although in separate microdomains, and represent the decompression stage at 565 °C and 3.5 kbar.

Description: The early (Devonian) collisional stage in SW Iberia has been investigated through the analysis of deformation in the Cubito-Moura schists, the main lithology of an Allochthonous Complex putatively rooted in the suture between the Ossa-Morena and South Portuguese zones. The first deformation in these schists (D 1 ) is recorded as a S 1 -L 1 mylonitic fabric well preserved in early quartz veins. Subsequent D 2 deformation caused the main folds and the main (S 2 ) foliation. After restoration, the stretching lineation (L 1 ) trends at a small angle with the Ossa-Morena/South Portuguese suture. This trend, together with the top-to-the-east kinematics determined from quartz microfabric is indicative of an oblique left-lateral collisional scenario in SW Iberia. Chlorite–white K-mica–quartz ± chloritoid multi-equilibrium calculations yield P–T conditions in the range 0.9–1.2 GPa and 300–400 °C, during the first collisional stage. P–T conditions during D 2 were 0.3–0.8 GPa and 400–450 °C, thus indicating an important stage of exhumation of the Allochthonous Complex during these two collisional events, after subduction of the Ossa-Morena Zone margin under the South Portuguese Zone continental crust. In the general context of the Variscan orogen, dominated by dextral collision, the left-lateral convergence in SW Iberia can be explained in terms of the Avalonian salient represented by the South Portuguese Zone, which would impinge between Iberia and Morocco.

Description: The Cova Gran de Santa Linya (Lleida, Spain) is a recently discovered site, with a broad chrono-cultural sequence that contains archaeological levels dating to the Middle Palaeolithic, Early Upper Palaeolithic, Late Upper Palaeolithic, Neolithic and Early Bronze Age. We present the chronometric and stratigraphic context of these occupations, which were dated using 14 C accelerator mass spectrometry and thermoluminescence. The sequence provides important indicators that aid in the reconstruction of the history of human occupation on the southern slopes of the Spanish Pyrenees over the past 50,000 years. Copyright © 2011 John Wiley & Sons, Ltd.

Description: Nanosystems based on polymers have attracted much attention due to the almost infinite diversity. In the past decades, the application of supercritical fluids for polymeric particle precipitation has been developed as an alternative to conventional processes. Here, precipitation of an acrylic copolymer was attempted by the rapid expansion of supercritical solutions (RESS) and successful by supercritical antisolvent (SAS) processes. In addition, the nanoparticles were characterized with different techniques. The polymer concentration, pressure, temperature, liquid solution flow rate and nozzle diameter effects were also evaluated with regard to particle size and the particle size distribution of this polymer. An acrylic copolymer used for drug delivery to the intestines was processed by supercritical CO 2 to improve its final features. The effects of the operating conditions were evaluated regarding morphology, particle size and particle size distribution, in order to optimize the nanoparticle production.

Description: ABSTRACT Antimicrobial compounds are widespread, emerging contaminants in the aquatic environment and may threaten ecosystem and human health. This study characterized effects of antimicrobial compounds common to human and veterinary medicine, aquaculture, and consumer personal care products [erythromycin (ERY), sulfamethoxazole (SMX), oxytetracycline (OTC), and triclosan (TCS)] in the grass shrimp Palaemonetes pugio . The effects of antimicrobial treatments on grass shrimp mortality and lipid peroxidation activity were measured. The effects of antimicrobial treatments on the bacterial community of the shrimp were then assessed by measuring Vibrio density and testing bacterial isolates for antibiotic resistance. TCS (0.33 mg/L) increased shrimp mortality by 37% and increased lipid peroxidation activity by 63%. A mixture of 0.33 mg/L TCS and 60 mg/L SMX caused a 47% increase in shrimp mortality and an 88% increase in lipid peroxidation activity. Exposure to SMX (30 mg/L or 60 mg/L) alone and to a mixture of SMX/ERY/OTC did not significantly affect shrimp survival or lipid peroxidation activity. Shrimp exposure to 0.33 mg/L TCS increased Vibrio density 350% as compared to the control whereas SMX, the SMX/TCS mixture, and the mixture of SMX/ERY/OTC decreased Vibrio density 78–94%. Increased Vibrio antibiotic resistance was observed for all shrimp antimicrobial treatments except for the mixture of SMX/ERY/OTC. Approximately 87% of grass shrimp Vibrio isolates displayed resistance to TCS in the control treatment suggesting a high level of TCS resistance in environmental Vibrio populations. The presence of TCS in coastal waters may preferentially increase the resistance and abundance of pathogenic bacteria. These results indicate the need for further study into the potential interactions between antimicrobials, aquatic organisms, and associated bacterial communities. © 2014 Wiley Periodicals, Inc. Environ Toxicol, 2014.

Description: Ecology, Volume 95, Issue 4, Page 1033-1044, April 2014. Environmental conditions and individual strategies in early life may have a profound effect on fitness. A critical moment in the life of an organism occurs when an individual reaches independence and stops receiving benefits from its relatives. Understanding the consequences of individual strategies at the time of independence requires quantification of their fitness effects. We explored this period in the Red Grouse (Lagopus lagopus scoticus). In this system, testosterone and parasite (Trichostrongylus tenuis) levels are known to influence survival and reproduction, the two key components of individual fitness. We experimentally and simultaneously manipulated testosterone and parasites at three levels (high, intermediate, and control levels for both factors) in 195 young males in five populations using a factorial experimental design. We explored the effects of our treatments on fitness by monitoring reproduction and survival throughout the life of all males and estimating λind, a rate-sensitive index of fitness. Parasite challenges increased the number of worms with a time lag, as previously found. However, we did not find significant effects of parasite manipulations on fitness, possibly because parasite abundance did not increase to harmful levels. Our hormone manipulation was successful at increasing testosterone at three different levels. Such increases in hormone levels decreased overall fitness. This was caused by reduced offspring production in the first breeding attempt rather than by any effect of the treatment on bird survival. Our results highlight that investing in high testosterone levels at independence, a strategy that might enhance short-term recruitment probability in territorial species such as Red Grouse, has a fitness cost, and can influence the resolution of the trade-off between reproduction and survival later in life.

Description: [1]  We have assessed the characteristics of clasts along Curiosity's traverse to shed light on the processes important in the genesis, modification and transportation of surface materials. Pebble- to cobble-sized clasts at Bradbury Landing, and subsequently along Curiosity's traverse to Yellowknife Bay, reflect a mixing of two endmember transport mechanisms. The general clast population likely represents material deposited via impact processes, including meteorite fragments, ejecta from distant craters, and impactites consisting of shocked and shock melted materials from within Gale Crater, which resulted predominantly in larger, angular clasts. A subset of rounded pebble-sized clasts has likely been modified by intermittent alluvial or fluvial processes. The morphology of this rounded clast population indicates that water was a more important transporting agent here than at other Mars sites that have been studied in situ. Finally, we identified populations of basalt clasts and porphyritic clasts of undetermined composition by their morphologic and textural characteristics; basalts are confirmed by geochemical data provided by ChemCam.