Effects of dietary exposure to the pyrethroid pesticide esfenvalerate on medaka (Oryzias latipes)

The pyrethroid insecticide esfenvalerate is widely used on orchard crops throughout California. In the aquatic environment, this compound is likely to accumulate in sediments, food particles and benthic organisms due to its lipophilicity and environmental persistence. This pilot project tested the hypothesis that esfenvalerate is toxic to medaka (Oryzias latipes) when taken up with the diet. For 7 days fish were fed diets, which contained esfenvalerate in three different concentrations (4, 21, 148 mg/kg, measured). Endpoints measured were mortality, fecundity, fertilization and hatching success of embryos, viability of larvae and cellular stress protein (hsp60, hsp70, hsp90) levels. The toxicity of aqueous exposure of medaka to esfenvalerate was also determined. Whereas the 96-h LC50 in the aqueous exposure was <9.4 microg/l, the dietary exposure did not cause mortality. Possible effects of dietary esfenvalerate were seen on fertilization and hatching success and the number of non-viable larvae. Expression of hsp60 and hsp90 showed a dose-dependent response pattern.     

Natural hazards in Nordic Countries

Compared to many areas of the world, the human losses caused by natural hazards are smaller in Nordic countries. This is mainly due to the low population density in the exposed areas. However, the economic losses are significant and the geohazards picture varies among the countries. The predominant natural hazards in Nordic countries are floods, landslides, and, with the exception of Denmark, snow avalanche. Volcanoes and earthquakes are major geohazards in Iceland, and parts of Norway are susceptible to seismic activity. Slidetriggered tsunamis also represent a threat to parts of the coastal areas of Nordic countries and Greenland.     

Shocked chromites in fossil L chondrites: A Raman spectroscopy and transmission electron microscopy study

Chromites from Middle Ordovician fossil L chondrites and from matrix and shock‐melt veins in Catherwood, Tenham, and Coorara L chondrites were studied using Raman spectroscopy and TEM. Raman spectra of chromites from fossil L chondrites showed similarities with chromites from matrix and shock‐melt veins in the studied L chondrite falls and finds. Chromites from shock‐melt veins of L chondrites show polycrystallinity, while the chromite grains in fossil L chondrites are single crystals. In addition, chromites from shock‐melt veins in the studied L chondrites have high densities of planar fractures within the subgrains and many subgrains show intergrowths of chromite and xieite. Matrix chromite of Tenham has similar dislocation densities and planar fractures as a chromite from the fossil meteorite Golvsten 001 and higher dislocation densities than in chromite from the fossil meteorite Sextummen 003. Using this observation and knowing that the matrix of Tenham experienced 20–22 GPa and <1000° C, an upper limit for the P,T conditions of chromite from Golvsten 001 and Sextummen 003 can be estimated to be 20–22 GPa and 1000° C (shock stage S3–S6) and 20 GPa and 1000° C (S3–S5), respectively, and we conclude that the studied fossil meteorite chromites are from matrix.     

Development of an instantaneous GNSS/MEMS attitude determination system

Global navigation satellite systems (GNSS) are well suited for attitude determination. The key to high-precision GNSS-attitude determination is the ambiguity resolution. In case of kinematic applications, the rapidity of this process is of particular importance. We present a new instantaneous attitude determination system for GNSS-challenged environments. The single-epoch ambiguity resolution is performed by the ambiguity function method aided by a micro-electro-mechanical system (MEMS), leading to success rates above 99 %. The GNSS/MEMS fusion is realized by the use of an extended Kalman filter. When the system is stationary, a state vector augmentation with a shaping filter reduces systematic effects in the GNSS-attitudes. By means of two field experiments, the system was tested successfully. Despite poor GNSS measurement conditions, it provided reliable and accurate results, with empirical standard deviations in the range of 0.03–0.1 deg for the yaw angle.     

Carbonate and silicate weathering in two presently glaciated, crystalline catchments in the Swiss Alps

We present a weathering mass balance of the presently glaciated Rhône and Oberaar catchments, located within the crystalline Aar massif (central Switzerland). Annual chemical and physical weathering fluxes are calculated from the monthly weighted means of meltwater samples taken from July, 1999 to May, 2001 and are corrected for precipitation inputs. The meltwater composition issuing from the Oberaar and Rhône catchments is dominated by calcium, which represents 81% and 55% of the total cation flux respectively (i.e. 555 and 82-96 keq km⁻² yr⁻¹). The six to seven times higher Ca²⁺ denudation flux from the Oberaar catchment is attributed to the presence of a strongly foliated gneissic zone. The gneissic zone has an elevated calcite content (as reflected by the 4.6 times higher calcite content of the suspended sediments from Oberaar compared to Rhône) and a higher mechanical erosion rate (resulting in a higher flux of suspended sediment). The mean flux of suspended calcite of the Oberaar meltwaters during the ablation period is 7 times greater than that of the Rhône meltwaters. Taking the suspended calcite as a proxy for the total (including sub-glacial sediments) weathering calcite surface area, it appears that the available surface area is an important factor in controlling weathering rates. However, we also observe an increased supply of protons for carbonate dissolution in the Oberaar catchment, where the sulphate denudation flux is six times greater. Carbonic acid is the second important source of protons, and we calculate that three times as much atmospheric CO₂ is drawn down (short term) in the Oberaar catchment. Silica fluxes from the two catchments are comparable with each other, but are 100 kmol km² yr⁻¹ lower than fluxes from physically comparable, non-glaciated basins.     

Controls on erosion patterns and sediment transport in a monsoonal,tectonically quiescent drainage,Song Gianh,central Vietnam

The Song Gianh is a small‐sized (~3500 km²), monsoon‐dominated river in northern central Vietnam that can be used to understand how topography and climate control continental erosion. We present major element concentrations, together with Sr and Nd isotopic compositions, of siliciclastic bulk sediments to define sediment provenance and chemical weathering intensity. These data indicate preferential sediment generation in the steep, wetter upper reaches of the Song Gianh. In contrast, detrital zircon U‐Pb ages argue for significant flux from the drier, northern Rao Tro tributary. We propose that this mismatch represents disequilibrium in basin erosion patterns driven by changing monsoon strength and the onset of agriculture across the region. Detrital apatite fission track and ¹⁰Be data from modern sediment support slowing of regional bedrock exhumation rates through the Cenozoic. If the Song Gianh is representative of coastal Vietnam then the coastal mountains may have produced around 132 000–158 000 km³ of the sediment now preserved in the Song Hong‐Yinggehai Basin (17–21% of the total), the primary depocenter of the Red River. This flux does not negate the need for drainage capture in the Red River to explain the large Cenozoic sediment volumes in that basin but does partly account for the discrepancy between preserved and eroded sediment volumes. OSL ages from terraces cluster in the Early Holocene (7.4–8.5 ka), Pre‐Industrial (550–320 year BP) and in the recent past (ca. 150 year BP). The older terraces reflect high sediment production driven by a strong monsoon, whereas the younger are the product of anthropogenic impact on the landscape caused by farming. Modern river sediment is consistently more weathered than terrace sediment consistent with reworking of old weathered soils by agricultural disruption.     

The false Basel earthquake of May 12, 1021

The Basel (CH) area is a place with an increased seismic hazard. Consequently, it is essential to scrutinize a famous statement by Stumpf (Gemeiner loblicher Eydgnoschafft Stetten, Landen und Völckeren Chronikwirdiger thaaten beschreybung. Durch Johann Stumpffen beschriben, 1548) that allegedly a large earthquake took place in Basel in 1021. This can be disproved unambiguously by applying historical and philosophical methods.     

Mediterranean climate extremes in synoptic downscaling assessments

The behaviour of precipitation and maximum temperature extremes in the Mediterranean area under climate change conditions is analysed in the present study. In this context, the ability of synoptic downscaling techniques in combination with extreme value statistics for dealing with extremes is investigated. Analyses are based upon a set of long-term station time series in the whole Mediterranean area. At first, a station-specific ensemble approach for model validation was developed which includes (1) the downscaling of daily precipitation and maximum temperature values from the large-scale atmospheric circulation via analogue method and (2) the fitting of extremes by generalized Pareto distribution (GPD). Model uncertainties are quantified as confidence intervals derived from the ensemble distributions of GPD-related return values and described by a new metric called “ratio of overlapping”. Model performance for extreme precipitation is highest in winter, whereas the best models for maximum temperature extremes are set up in autumn. Valid models are applied to a 30-year period at the end of the twenty-first century (2070–2099) by means of ECHAM5/MPI-OM general circulation model data for IPCC SRES B1 scenario. The most distinctive future changes are observed in autumn in terms of a strong reduction of precipitation extremes in Northwest Iberia and the Northern Central Mediterranean area as well as a simultaneous distinct increase of maximum temperature extremes in Southwestern Iberia and the Central and Southeastern Mediterranean regions. These signals are checked for changes in the underlying dynamical processes using extreme-related circulation classifications. The most important finding connected to future changes of precipitation extremes in the Northwestern Mediterranean area is a reduction of southerly displaced deep North Atlantic cyclones in 2070–2099 as associated with a strengthened North Atlantic Oscillation. Thus, the here estimated future changes of extreme precipitation are in line with the discourse about the influence of North Atlantic circulation variability on the changing climate in Europe.     

基于变化轨迹探测的植被景观格局动态分析——以塔里木河下游生态输水区域为例

 在遥感与GIS技术支持下,以2006、2007、2009、2010年Landsat-5/TM影像与2008年的CBERS/CCD影像为主要数据源,获得5 a的植被/非植被类型图。在此基础上,提取并归纳5 a间的植被变化轨迹:恒定植被、恒定非植被、转变为植被、转变为非植被、非稳定变化。利用景观格局分析软件FRAGSTATS 3.3计算了变化轨迹景观格局的3种景观指标。结果表明,2006—2010年植被面积减小,主要因为生态输水量减小、输水间隔较大,导致草本植被、乔灌木幼苗死亡;恒定非植被的比重最大,表明非植被类型是研究区的基质,其次是转变为非植被的比重,说明5 a间植被的衰退程度要强于恢复程度;转变为植被与非稳定变化两种类型属于过渡性植被变化类型,受生态输水量、分布的制约严重;各种变化轨迹类型的形状规则较为稳定,其中以恒定非植被类型最稳定而非稳定变化类型最不稳定。