Barnacle fouling in the Mediterranean sponges Axinella polypoides and Axinella verrucosa

Secondary metabolites protect many marine sponges (Phylum: Porifera) from settlement by fouling organisms. Previous studies on the subtidal demosponge Axinella verrucosa collected in the Western Mediterranean led to the isolation of compounds that inhibited the settlement of cyprids larvae of the intertidal barnacle Balanus amphitrite, and the enzyme chitinase, which plays a key role in the molting cycle of crustaceans. However, in a field survey conducted at three locations in Israel, Eastern Mediterranean Sea, we observed that A. verrucosa is fouled by the subtidal barnacle Balanus trigonus, a previously unknown association. Settlement inhibition assays using B. amphitrite with chemical extracts from Israeli A. verrucosa and Axinella polypoides, a sympatric, congeneric sponge that seems not to be fouled by B. trigonus, showed that cyprid larvae of B. amphitrite were inhibited by the extracts of both sponges from settlement at concentrations several magnitudes lower than natural volumetric extract concentration in the sponges. These results indicate that, unlike the intertidal barnacle B. amphitrite, the subtidal B. trigonus is unaffected by the compounds from A. verrucosa, stressing and underlining the importance of using suitable target organisms (i.e. from the same habitat) to test for ecologically relevant antifouling activities.     

Combined Use of Remote Sensing and Continuous Monitoring to Analyse the Variability of Suspended-Sediment Concentrations in San Francisco Bay, California

Analysis of suspended-sediment concentration data in San Francisco Bay is complicated by spatial and temporal variability. In situ optical backscatterance sensors provide continuous suspended-sediment concentration data, but inaccessibility, vandalism, and cost limit the number of potential monitoring stations. Satellite imagery reveals the spatial distribution of surficial-suspended sediment concentrations in the Bay; however, temporal resolution is poor. Analysis of thein situ sensor data in conjunction with the satellite reflectance data shows the effects of physical processes on both the spatial and temporal distribution of suspended sediment in San Francisco Bay. Plumes can be created by large freshwater flows. Zones of high suspended-sediment concentrations in shallow subembayments are associated with wind-wave resuspension and the spring-neap cycle. Filaments of clear and turbid water are caused by different transport processes in deep channels, as opposed to adjacent shallow water. Crown     

Quaternary deformation, river steepening, and heavy precipitation at the front of the Higher Himalayan ranges

New geologic mapping in the Marsyandi Valley of central Nepal reveals the existence of tectonically significant Quaternary thrust faults at the topographic front of the Higher Himalaya. The zone of recent faulting is coincident with an abrupt change in the gradient of the Marsyandi River and its tributaries, which is thought to mark the transition from a region of rapid uplift in the Higher Himalayan ranges to a region of slower uplift to the south. Uplift of the Higher Himalaya during the Quaternary is not entirely due to passive uplift over a deeply buried ramp in the Himalayan sole thrust, as is commonly believed, but partially reflects active thrusting at the topographic front. The zone of active thrusting is also coincident with a zone of intense monsoon precipitation, suggesting a positive feedback relationship between focused erosion and deformation at the front of the Higher Himalayan ranges.     

Tetracycline marking of coregonids at the time of egg fertilization

Tetracycline marking of otoliths can be achieved by osmotic importation at fertilization when hardening is conducted in tetracycline solutions. Marks produced are recognizable even in fish of catchable size without a very extensive otolith preparation. The method can contribute to estimations of stocking efficiency and to discern recruits of natural and artificial reproduction.     

Palaeobiogeography of Early Jurassic Lithiotis-type bivalve buildups as recovery effect after Triassic/Jurassic mass extinction and their connections with Asian palaeogeograph

The huge, up to 40-50 cm long bivalves, Lithiotis, Cochlearites and Lithioperna, which dominated within “Lithiotis” facies (sensu – Fraser et al., 2004 with lit-erature cited therein), are most significant representa-tives of buildup-maker of shallow marine/lagoonal bivalve mounds (reefs) in numerous places of Tethyan- Panthalassa margins during Pliensbachian-Early Toar-cian times. The distribution of Lithiotis-facies bivalves from Western (Spain, Italy) and Middle Europe (Slo-venia, Croatia, Albania) trough north Africa (Morocco) and Arabian Peninsula (Oman, Arabian Emirates) up to Timor Island, Himalaya Mts (Nepal, China) and west-ern margin of both Americas (USA, Peru) indicates world-wide, rapid expansion of such Lithiotis-type bivalves (Leinfelder et al., 2002; Fraser et al., 2004; Krobicki et al., 2008). The Early Jurassic migration routes were connected both with break-up of Pangea and oceanic circulation, which facilitated high speed of distribution of larva’s of such oyster-like bivalves.     

Ergebnisse bisheriger Abklärungen über die systematische Beziehung zwischen Sommeralbeli und Winteralbeli (Coregonus lavaretus (L.)) im Walensee

A whitefish population considered to consist of two morphologically similar subpopulations is analyzed. Since a reproductive barrier existing earlier between the two subpopulations has lost its effectiveness, only one population exists today, having a very long reproductive period.      

Timing of glacier advances and climate in the High Tatra Mountains (Western Carpathians) during the Last Glacial Maximum

During the Last Glacial Maximum (LGM), long valley glaciers developed on the northern and southern sides of the High Tatra Mountains, Poland and Slovakia. Chlorine-36 exposure dating of moraine boulders suggests two major phases of moraine stabilization, at 26–21 ka (LGM I — maximum) and at 18 ka (LGM II). The dates suggest a significantly earlier maximum advance on the southern side of the range. Reconstructing the geometry of four glaciers in the Sucha Woda, Pańszczyca, Mlynicka and Velicka valleys allowed determining their equilibrium-line altitudes (ELAs) at 1460, 1460, 1650 and 1700 m asl, respectively. Based on a positive degree-day model, the mass balance and climatic parameter anomaly (temperature and precipitation) has been constrained for LGM I advance. Modeling results indicate slightly different conditions between northern and southern slopes. The N–S ELA gradient finds confirmation in slightly higher temperature (at least 1 °C) or lower precipitation (15%) on the south-facing glaciers during LGM I. The precipitation distribution over the High Tatra Mountains indicates potentially different LGM atmospheric circulation than at the present day, with reduced northwesterly inflow and increased southerly and westerly inflows of moist air masses.     

Observations of the temperature and polarization anisotropies with Boomerang 2003

The Boomerang experiment completed its final long duration balloon (LDB) flight over Antarctica in January 2003. The focal plane was upgraded to accommodate four sets of 145 GHz polarization sensitive bolometers (PSBs), identical to those to be flown on the Planck HFI instrument. Approximately, 195 hours of science observations were obtained during this flight, including 75 hours distributed over 1.84% of the sky and an additional 120 hours concentrated on a region covering 0.22% of the sky. We derive the angular power spectra of the cosmic microwave background (cmb) temperature and polarization anisotropies from these data. The temperature anisotropies are detected with high signal to noise on angular scales ranging from several degrees to 10 arcminutes. The curl-free (EE) component is detected at 4.8σ, and a two-sigma upper limit on the curl (BB) component of 8.6 μK² is obtained on scales corresponding to 0.5°. Both the temperature and polarization anisotropies are found to be consistent with a concordance ΛCDM cosmology that is seeded by adiabatic density perturbations. In addition to the cmb observations, Boomerang03 surveyed a 300 square degree region centered on the Galactic plane. These observations represent the first light for polarization sensitive bolometers, which are currently operational in two South-Pole based polarimeters, as well as Planck HFI, at frequencies ranging from 100 to 350 GHz (3 mm to 850 μm).     

Modelling hydraulic and capillary-driven two-phase fluid flow in unsaturated concretes at the meso-scale with a unique coupled DEM-CFD technique

The goal of the research was to demonstrate the impact of thin porous interfacial transition zones (ITZs) between aggregates and cement matrix on fluid flow in unsaturated concrete caused by hydraulic/capillary pressure. To demonstrate this impact, a novel coupled approach to simulate the two-phase (water and moist air) flow of hydraulically and capillary-driven fluid in unsaturated concrete was developed. By merging the discrete element method (DEM) with computational fluid dynamics (CFD) under isothermal settings, the process was numerically studied at the meso-scale in two-dimensional conditions. A flow network was used to describe fluid behaviour in a continuous domain between particles. Small concrete specimens of a simplified particle mesostructure were subjected to fully coupled hydro-mechanical simulation tests. A simple uniaxial compression test was used to calibrate the pure DEM represented by bonded spheres, while a permeability and sorptivity test for an assembly of spheres was used to calibrate the pure CFD. For simplified specimens of the pure cement matrix, cement matrix with aggregate, and cement matrix with aggregate and ITZ of a given thickness, DEM/CFD simulations were performed sequentially. The numerical results of permeability and sorptivity were directly compared to the data found in the literature. A satisfactory agreement was achieved. Porous ITZs in concrete were found to reduce sorption by slowing the capillary-driven fluid flow, and to speed the full saturation of pores when sufficiently high hydraulic water pressures were dominant.