A test of Sporormiella representation as a predictor of megaherbivore presence and abundance

Spores of the dung fungus Sporormiella have been suggested to indicate the presence, perhaps also the abundance of past megaherbivore populations. Nonetheless, basic studies demonstrating a correlation between Sporormiella concentration in lacustrine sediments and modern herbivore abundance are lacking. This study of Sporormiella representation in grazed and ungrazed landscapes provides supporting evidence for the application of Sporormiella as an indicator of megaherbivore presence and abundance in ancient landscapes. However, Sporormiella representation is spatially sensitive to the distance from the dung source. In lakes where Sporomiella are abundant in shoreline sediments, they decline sharply with increasing distance from the lake edge. Although this study provides supporting evidence for the application of Sporormiella as a proxy for herbivore presence and abundance, independent proxies should be applied in conjunction with Sporormiella to control for changes in lake size.     

Experimental study on the bidirectional inelastic deformation capacity of U‐shaped steel dampers for seismic isolated buildings

Hysteretic dampers are used to dissipate earthquake‐induced energy in base‐isolated structures by acquiring inelastic deformations, rendering their hysteretic behavior of vital importance. The present paper focuses on investigating the behavior of U‐shaped steel dampers under bidirectional loading; this is significantly different from their corresponding uniaxial behavior. Two main sets of loading tests on full‐scale specimens are conducted in this regard: (i) quasi‐static tests with simple histories and (ii) dynamic tests with realistic loading histories. Based on the results obtained in the quasi‐static tests, an interaction curve that accounts for the reduction of the cyclic deformation capacity is proposed. However, the fidelity of this relation must be assessed under loading conditions similar to those of a seismically isolated structure subjected to an earthquake, which represents the goal of the second set of tests. The results of the dynamic tests validate the proposed interaction curve for estimating the deformation capacity of U‐shaped steel dampers under bidirectional loading. Copyright © 2015 John Wiley & Sons, Ltd.     

Light variations of spotted stars: Second approximation

In the framework of the direct photometric problem we obtained an analytical representation of the light variations of spotted stars adopting quadratic limb-darkening law. The btained results can be a basis for the solution of the inverse photometric problem for spotted late FK Com-type giants.     

Archaeomagnetic investigation of two mediaeval brick constructions in north Belgium and the magnetic anisotropy of bricks

Archaeomagnetic dates derived from geomagnetic field direction records in baked materials are proposed for a mediaeval brick kiln (from inclination I and declination D) and for bricks from a brick wall (from I only) in northern Belgium. They are used to verify whether a brick chronology based on the format of bricks is feasible in Flanders. The brick kiln yielded a highly reliable average magnetization direction corresponding to an archaeomagnetic date around A.D. 1650, using the British and French geomagnetic field secular variation curves as a reference, at least half a century younger than expected from historical data. The fidelity of the geomagnetic records was controlled by measuring the magnetic anisotropy of the bricks. Anisotropy of magnetic susceptibility (AMS) measurements demonstrate that the bricks have a shape related magnetic fabric, which is induced during the molding process. A test to control whether AMS can substitute for the anisotropy of thermo‐remanent magnetization (ATRM) failed because of induced changes during laboratory heating. © 2003 Wiley Periodicals, Inc.     

Internal structure of massive terrestrial planets

Planetary formation models predict the existence of massive terrestrial planets and experiments are now being designed that should succeed in discovering them and measuring their masses and radii. We calculate internal structures of planets with one to ten times the mass of the Earth (Super-Earths) to obtain scaling laws for total radius, mantle thickness, core size and average density as a function of mass. We explore different compositions and obtain a scaling law of R∝M0.267-0.272 for Super-Earths. We also study a second family of planets, Super-Mercuries with masses ranging from one mercury-mass to ten mercury-masses with similar composition to the Earth's but with a larger core mass fraction. We explore the effect of surface temperature and core mass fraction on the scaling laws for these planets. The scaling law obtained for the Super-Mercuries is R∝M∼0.3.     

Spatial distribution of canine faeces in Buenos Aires suburbs: implications for public health

Canine faecal contamination contributes to environmental degradation and increases the exposure of humans – mainly children – to helminth infections. We studied the magnitude and spatial distribution of faecal contamination on the pavements of two neighbourhoods representative of Buenos Aires suburbs. The pavements of a low-income neighbourhood (LIN) and a middle-income neighbourhood (MIN) were selected at random. Field maps including all substrates and objects observed on each pavement were drawn, viewed from above, on millimetre paper at 1:100 scale. Data were then loaded into a geographic information system (GIS) Arc View 3.1 with a digitiser board. The spatial distribution of faeces and its association with substrates or standing elements were analysed at three scales: substrate, pavement and neighbourhood.
Permeable substrate cover was higher in LIN (75%) than in MIN (35%). The faeces were not homogeneously distributed on the substrates. In both neighbourhoods, the substrates with >50 per cent grass cover showed a significantly higher proportion of faeces than those with <50 per cent grass cover, bare soil and tile. At pavement scale, the number of faeces on pavements was not related to either the number of trees, posts and domiciled dogs in the block, or with the number of faeces and percentage cover of each substrate. At patch scale, substrate patches with faeces were larger than those without faeces. Patches with faeces did not differ in shape between neighbourhoods and were more regularly shaped than patches without faeces.
The spatial distribution of faeces relative to each other was almost random, even when analysed in relation to trees or standing objects. Strategies for the sustainable control of this problem are suggested.