Palaeo- and rock-magnetic investigations across Jurassic-Cretaceous boundary at St Bertrand’s Spring,Drôme,France: applications to magnetostratigraphy

Palaeo- and rock-magnetic investigations of the St Bertrand’s Spring (Le Ravin de Font de St Bertrand) locality in France were carried out in order to contribute to, and improve, the stratigraphy of the Jurassic-Cretaceous boundary interval. Magnetic susceptibility shows slightly diamagnetic behaviour in the lowermost part of the profile and an increase (paramagnetic) towards its middle and upper parts. Rock-magnetic measurements throughout the section show magnetite as the main magnetic fraction, together with traces of hematite. Additionally, thermal demagnetization indicates the presence of goethite. Our magnetostratigraphy indicates three normal/reversed polarity sequences; possibly encompassing the magnetozones M19r to the M17n. This suggests that the St Bertrand section straddles the Tithonian/Berriasian boundary and reaches the middle Berriasian sensu lato.     

Regional Flood Frequency Analysis Based on L-Moment Approach (Case Study Tisza River Basin)

Water Resources - Floods are one of the most common natural hazards and as such, they are causing a great loss of human life as well as great economic damages. Flood frequency analysis (FFA) is...     

Analysis of the Relationship Between the Solar X-Ray Radiation Intensity and the D-Region Electron Density Using Satellite and Ground-Based Radio Data

Increases in the X-ray radiation that is emitted during a solar X-ray flare induce significant changes in the ionospheric D region. Because of the numerous complex processes in the ionosphere and the characteristics of the radiation and plasma, the causal-consequential relationship between the X-ray radiation and ionospheric parameters is not easily determined. In addition, modeling the ionospheric D-region plasma parameters is very difficult because of the lack of data for numerous time- and space-dependent physical quantities. In this article we first give a qualitative analysis of the relationship between the electron density and the recorded solar X-ray intensity. After this, we analyze the differences in the relationships between the D-region response and various X-ray radiation properties. The quantitative study is performed for data observed on 5 May 2010 in the time period between 11:40 UT?–?12:40 UT when the GOES 14 satellite detected a considerable X-ray intensity increase. Modeling the electron density is based on characteristics of the 23.4 kHz signal emitted in Germany and recorded by the receiver in Serbia.     

Land use optimization for sustainable development of mountain regions of western Serbia

This study analyses the possibilities for optimal land use structure in mountainous areas of rural Serbia, which is faced with problems such as unfavorable terrain characteristics and inadequate land use patterns causing economic underdevelopment and increasing population migration. In the case of a small privately owned farm in Western Serbia, optimal land use pattern is determined using the linear programming model. The objective function-cost-effectiveness or soil erosion reduction, as well as constraints, are formulated using the benefit-cost ratio (BCR) for a 15-year production period and soil losses data calculated using the Universal Soil Loss Equation (USLE). The best results are achieved using the scenario with the aim to minimize soil erosion, considering the BCR in the constraints. This scenario is proposed since it was registered that the benefit for landowners would increase by five times, while the losses of land would decline about 80%. The sensitivity analysis of investments is performed to check whether the price variation affects the cost-effectiveness of proposed land use. Results show that market changes (nine cases are considered) do not lead to significant changes in land use allocation. Proposed land use pattern improves the environmental condition, strengthens the rural economy and thus offers the greatest potential for sustainable development of mountainous rural areas.     

Young Age for the Veritas Asteroid Family Confirmed?

We present a comprehensive analysis of the dynamics of Veritas family members located in a chaotic strip centeredat 3.174 AU. A total of 600 chaotic members of the family and their clones were integrated for 100 Myr, and the variation of the distance with respect to the barycenter of the family have been computed forall of them. A simple classification of the prevailing behaviors hasbeen introduced to help identify typical dynamical patterns and states that could affect an estimate of the upper bound to the age of the family. We pointed out the importance of the temporary captures in thequasi-stable states, which occur often enough to affect the statistical analysis of the exits. The results are compatible with the young age (<100 Myr) for the family of Veritas, but we cannot say precisely how young it really is. This revised version was published online in July 2006 with corrections to the Cover Date.     

Column Density Distribution of Galactic Lyα AbsorptionSystems

A simple consistency argument for hypothesis of the galactic halo origin of the Lyα forest absorption lines is advanced, based on the recent determination of column-density vs. impact parameter relation for the low-redshift gaseous galactic haloes. It is shown that observations of neutral hydrogen absorption around luminous galaxies are consistent with the index of the power-law column density distribution derived from statistical analyses of large samples of high-redshift Lyα forest lines.PACS: 98.62.Ra, 98.62.Gq, 98.80.Es This revised version was published online in July 2006 with corrections to the Cover Date.     

DNA damage and apoptosis in the mussel Mytilus galloprovincialis

The effects of known genotoxic substances (4-nitroquinoline-N-oxide, benzo[a]pyrene, teniposide, etoposide, cycloheximide, tributyltin) on human cells (FLC, HL-60) and on mussels were investigated. The correlations between formation of DNA strand breaks and DNA fragmentation characteristic for the process of apoptosis were estimated. Strand breaks induced by 4-nitroquinoline-N-oxide and benzo[a]pyrene did not correlate with DNA fragmentation detected in the process of apoptosis. Induction of internucleosomal DNA fragmentation in HL-60 cells was initiated by teniposide, etoposide and tributyltin, while in the gills of mussels this was detected only with tributyltin. Levels of DNA strand breaks in natural mussel populations, living at locations under the influence of urban and industrial wastes, do not mirror the apoptotic processes.     

An analytical representation of ephemeris data

An algebraic method for the resolution of tabulated function into a class of elementary functions is examined on the high precision ephemeris data from the JPL DE 200.     

Resonant electron scattering by metastable nitrogen

The resonant electron impact quenching of metastable molecules might be important for understanding the phenomena in the upper atmosphere. In order to obtain information about the relative importance of this scattering event the resonant cross sections for electron scattering by metastable nitrogen in the $\text{A}{}^3\text{∑}\text{u}\text{+}$ state were calculated using the “boomerang” model and quenching rates for this state were evaluated for the altitudes of 130,170 and 210km. The obtained quenching rates are small (?5 × 10^?3 s^?1), even with respect to the radiative transition rate showing that under the considered conditions this process is unimportant for population of nitrogen $\text{A}{}^3\text{∑}\text{u}\text{+}$ state in the Earth's thermosphere.