How cold was it for Neanderthals moving to Central Europe during warm phases of the last glaciation?

Precise estimates of mean annual temperature (MAT) for when Neanderthals occupied Central Europe are critical for understanding the role that climatic and associated environmental factors played in Neanderthal migrations and in their ultimate extinction. Neanderthals were continuously present in the relatively warm regions of southern and Western Europe in the Pleistocene but only temporarily settled Central Europe (CE), presumably because of its colder and less hospitable climate. Here, we present a new approach for more spatially and temporally accurate estimation of palaeotemperatures based on the stable oxygen isotope composition of phosphates extracted from animal teeth found at sites linked directly to concurrent Neanderthal occupation. We provide evidence that Neanderthals migrated along the Odra Valley of CE during warmer periods throughout the Upper Pleistocene. The MATs during these migrations were about 6.8 °C for the warm phase of Oxygen Isotope Stage OIS 5a–d (prior to the OIS4 cold event) at ～115–74,000 yr BP and about 6.3 °C during the early OIS 3 warm phase ～59–41,000 yr BP. Our results show that temperatures during these phases peaked 2–4 °C above longer term estimates from ice cores and pollen records. We argue that our approach can provide valuable insights into evaluating the role of climate in human migration patterns in the Pleistocene.     

Constraining the degree of the dominant mode in QQ Vir

We present early results of the application of a method which uses multicolor photometry and spectroscopy for ? discrimination. This method has been successfully applied to the pulsating hot subdwarf Balloon?090100001. Here we apply the method to QQ?Vir (PG1325+101). This star was observed spectroscopically and photometrically in 2008. Details on spectroscopy can be found in Telting et al. (Astrophys. Space Sci. 2010, this volume), while photometry and preliminary results on ? discrimination are provided here. The main aim of this work was to compare the value of the ? parameter derived for the main mode in QQ?Vir to previously published values derived by using different methods.     

Inter-decadal Variability in Phytoplankton Community in the Middle Adriatic (Kaštela Bay) in Relation to the North Atlantic Oscillation

Evaluation of a 45-year data set of primary production (PP), a 30-year data set of phytoplankton biomass, and a 51-year data set of species composition shows an increase of phytoplankton biomass and abundance in the period from the mid-1980s to the mid-1990s. Phytoplankton biomass showed bimodal seasonal cycles, with winter and spring maxima, which did not change over the past 30 years. Diatoms were the most abundant functional group and they prevailed during the colder part of the year while the dinoflagellate contribution to the phytoplankton community increased in the warmer period from May to August. Diatoms showed a significant negative correlation with sea surface temperature (SST), while dinoflagellates were positively correlated with SST. An increase of phytoplankton abundance, particularly dinoflagellate, in the period from the mid-1980s to the mid-1990s coincided with years characterized by a high North Atlantic Oscillation (NAO) index. Primary production and chlorophyll a concentration in the spring period were negatively correlated with the NAO winter (DJFM) index, probably caused by increased precipitation associated with a low or negative NAO index. PP in winter during the mixing period was positively related to the NAO winter index associated with higher temperatures and dry conditions which brought more clear days and increased input of solar radiation.     

Framework for assessing probability of exceeding a specified liquefaction-induced settlement at a given site in a given exposure time

This paper presents a framework for assessing the probability of exceeding a specified liquefaction-induced settlement at a given site in a given exposure time. This framework deals not only with the effect of liquefaction (in terms of settlement) but also with probabilistic characterization of all possible ground motions at a given site (in terms of a joint distribution of a_max and M_w). Additionally, a new concept, referred to herein as liquefaction-induced settlement hazard curve, is introduced for assessing the annual rate of settlement exceedance at a given site. This settlement hazard curve concept has the potential to be a very useful tool in the field of geotechnical earthquake engineering. Satisfactory results are obtained in the demonstration examples analyzed with the proposed framework. Whereas the proposed framework is simple and effective, further refinements to this framework, especially on the treatment of epistemic uncertainty, are warranted.     

Observations of pulsating X-ray binaries 4U0900-40 and 4U1223-62

A rocket observation of two pulsating X-ray binaries, 4U0900-40 and 4U1223-62, found no evidence for periodic or quasiperiodic behavior on time scales down to 2 ms. Evidence for complex high-energy spectral features and intrapulse variability is presented for 4U0900-40.     

GRS 1915+105: the distance, radiative processes and energy-dependent variability

We present an exhaustive analysis of five broad-band observations of GRS 1915+105 in two variability states, χ and ω, observed simultaneously by the Proportional Counter Array (PCA) and High-Energy X-ray Timing Experiment (HEXTE) detectors aboard the Rossi X-ray Timing Explorer , and the Oriented Scintillation Spectrometer Experiment (OSSE) detector aboard the Compton Gamma-ray Observatory . We find all the spectra well fitted by Comptonization of disc blackbody photons, with very strong evidence for the presence of a non-thermal electron component in the Comptonizing plasma. Both the energy and the power spectra in the χ state are typical of the very high/intermediate state of black hole binaries. The spectrum of the ω state is characterized by a strong blackbody component Comptonized by thermal electrons and a weak non-thermal tail. We then calculate rms spectra (fractional variability as functions of energy) for the PCA data. We accurately model the rms spectra by coherent superposition of variability in the components implied by the spectral fits, namely a less variable blackbody and more variable Comptonization. The latter dominates at high energies, resulting in a flattening of the rms at high energies in most of the data. This is also the case for the spectra of the quasi-periodic oscillations present in the χ state. Then, some of our data require a radial dependence of the rms of the disc blackbody. We also study the distance to the source, and find   d ≃ 11 kpc  as the most likely value, contrary to a recent claim of a much lower value.     

Structural variation in Ca(TixSi1−x)O3 perovskites (1>x>0.65) and the ordered phase Ca2TiSiO6

High pressure perovskites in the system CaTiO₃?CaSiO₃ in the composition range from 0 to 50% CaSiO₃ have been re-examined using powder x-ray diffraction, Raman spectroscopy, and transmission electron microscopy. In runs performed at 9 GPa and 1200 °C, a solid solution is obtained with compositions ranging from CaTiO₃ to near Ca(Ti_0.65Si_0.35)O₃, and with the orthorhombic distortion in the CaTiO₃ end-member diminishing to pseudocubic for Ca(Ti_0.65Si_0.35)O₃. Raman spectra show intensity changes and band broadening which are attributed to the reduction of orthorhombic character, but still indicate lower than cubic symmetry for the entire solid solution range. An ordered intermediate, Ca₂TiSiO₆, has been recovered from a run at 14 GPa at 1200 °C. The space group is Fm3m, with a=7.410(2)?Å, and the compound has the double perovskite structure. In this structure, Si-rich octahedral sites and Ti-rich octahedral sites alternate along the three principal axes. Transmission electron microscopy confirms the presence of the Fm3m ordered structure, and also documents the presence of lesser amounts of at least three other ordered perovskite structures which are not resolved in the x-ray data. These may account for extra features observed in the Raman spectrum which are inconsistent with mode assignments for the Fm3m phase. Non face-centered ordering schemes for these regions are suggested based on modeling of the HRTEM patterns.     

Abschätzung der Geometrischen-und Genauigkeitsparameter eines Dreiecknetzes

Summary Approximate formulae (2,4) were derived for estimating the geometric parameters of a national triangular net, if its area P, in a certain way determined circumference O, and intended average length of the triangle side d are given. The formulae are given for n_Δ triangles, n_b points, n_d sides, and for r_g conditions with a trigonometrical net the bearings of which are measured, or r_l conditions with a trilateral net. Other approximate formulae (7–10) serve for estimating the mean errors M_g and M_l of adjusted observations and the positional errors M_x,y,g and M_x,y,l of the points of the net. Equation (11) gives the relation between the mean errors of observations m_g and m_l, which leads to the same positional accuracy with both bearing and distance measuring methods. The effect of the relative error R_d of the estimate of distance d is only observed with the geometric parameters and it is given by equations (6).

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Anschrift: Politickych vězňů 12, Praha 1-Nové Město.