bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic Hydrogels: Magnetic and Mechanical Measurements
Authors: Nikitin L.V. , Gladkov A.A. , Nikitin A.L. , Korovushkin A.E. , Nikolaev A.L. , Gopin A.V.
Published: June 2012

Several species of magntic hydrogels (ferrogels) are prepared, and their magnetic and magnetoelastic properties are examined. Three substance are used as the bases: agarose, polyacrylamide and Pluronic. All the gel matrices are filled with the same nanopowder: iron particles with the mean size about 30 nm. The critical concentrations of the magnetic phase, above which the normal gel networks cease to form, are estimated. The magnetization curves of the samples are measured at different stages of de-swelling, and their elastic properties are tested under a uniform magnetic field. The results indicate field-induced rigidity of magnetic hydrogels
Structure Properties of Polydisperse Magnetic Fluids
Authors: Krutikova Ekaterina , Ivanov Alexey
Published: June 2012

The structure properties of magnetic fluids are studied in the absence of an external magnetic field focusing the main attention on the influence of ferroparticle polydispersity. Magnetic fluid is modeled by a bidisperse system of uniformly magnetized hard spherical particles with permanent magnetic moments. The magnetic fluid microstructure is described with the help of the pair correlation function, and the ferroparticle polydispersity is taken into account within the bounds of bidisperse system. For the parameters, which are typical for real commercial magnetic fluids, we have obtained that the majority of ferroparticles (small is sizes) are less correlated. At the same time the large particles, which are small in number, are strongly correlated.
Effect of Electron Irradiation on the Non-Stoichiometric and Doped Lanthanum Manganites
Authors: Arbuzova T.I. , Naumov Sergey V. , Arbuzov V.L. , Danilov S.E. , Kostromitina Natalia V.
Published: June 2012

The effect of point lattice defects on the magnetic properties of manganites LaMnO3+δ, La0.67Ca0.33MnO3 and La0.67Ba0.33MnO3 has been investigated. Temperature dependences of magnetic susceptibility of the initial and electron-irradiated (F9×1018 e/cm2) samples were measured in the temperature range 80K
Effect of Partial Oxygen Isotope Substitution on the Phase Diagram of (Pr1-yEuy)0.7Ca0.3CoO3 Cobaltites
Authors: Babushkina N.A. , Taldenkov A.N. , Kalinov A.V. , Kuzmova T.G. , Kamenev A.A. , Kaul A.R.
Published: June 2012

Effect of the partial oxygen isotope substitution on (Pr1-yEuy)0.7Ca0.3CoO3 cobaltites was studied in detail for the crossover region (0.12<у<0.26) of the phase diagram. We prepared a series of the cobaltite samples with the different degrees of enrichment by the heavy oxygen isotope 18O, namely, containing 90%, 67%, 43%, 17%, and 0% of 18O. The Eu doping of the samples was chosen to be near and on the both sides of the crossover doping level ycr. Based on measurements of the ac magnetic susceptibility χ(Т) and electrical resistivity ρ(Т), we were able to analyze the evolution the sample properties with the change Eu and 18O content.
Effects of Non-Magnetic Doping upon Orbital and Magnetic Structures of Lanthanum Manganite
Authors: Gonchar Liudmila E. , Firsin Anton A. , Nikiforov Anatoliy E. , Popov Sergey E.
Published: June 2012

The theoretical model of the crystal structure of lanthanum manganite doped by non-Jahn-Teller ions is proposed. In order to describe the changes in the crystal structure and orbital state of manganese ions subsystem, we use modified shell model and virtual crystal model. The orbital ordering collapse is explained in terms of dynamical Jahn-Teller effect. The model of superexchange interaction helps to find the values of antiferromagnetic and ferromagnetic exchange parameters for dynamical and static orbital states of interacting ions. The magnetic structure of LaMn1-xGaxO3 is explained and magnetic resonance spectrum is predicted.
Nanophase Separation and Magnetic Spin Glass in Nd2/3Ca1/3MnO3
Authors: Kajňaková Marcela , Feher Alexander , Fertman Elena , Desnenko Vladimir , Beznosov Anatoly , Dolya Sergiy
Published: June 2012

A study of the low temperature magnetic state of polycrystalline colossal magnetoresistance perovskite Nd2/3Ca1/3MnO3 has been carried out. The data obtained, such as strongly divergent ZFC and FC static magnetizations and frequency dependent ac susceptibility, are evident of the glassy magnetic state of the system. Well defined maxima Tmax in the in-phase linear ac susceptibility χ curves were observed, indicating a spin-glass transition. Clear frequency dependence of the cusp temperature Tmax was found. The frequency dependence of Tmax was successfully analyzed by the dynamical scaling theory of a three-dimensional spin glass. Slow relaxation process and variety of relaxation times found imply a cluster glass magnetic state of the compound at low temperatures rather than a canonical spin glass state. The cluster glass state, accompanied by the multiple magnetic transitions of Nd2/3Ca1/3MnO3, might exist due to the competing interaction between the FM clusters and the AFM matrix induced by the complex nanophase segregated state of the compound.
Structure and Properties of Ca1-xEuxMnO3 Single Crystals
Authors: Naumov Sergey V. , Telegin S.V. , Kostromitina Natalia V. , Solin N.I. , Elokhina L.V. , Tsvetkov D.S. , Patselov A.M. , Loshkareva N.N.
Published: June 2012

The crystal growth of electron-doped manganites Ca1-xEuxMnO3by the floating zone method is reported. The special features of the growth parameters are discussed. Results of x-ray analysis, magnetic and transport characteristics are shown.
Functional-Integral Approach to the Investigation of the Spin-Spiral Magnetic Order and Phase Separation
Authors: Arzhnikov Anatoly K. , Groshev A.G.
Published: June 2012

We investigate a two–dimensional single-band Hubbard model with a nearest–neighbor hopping. We treat a commensurate collinear order as well as incommensurate spiral magnetic phases at a ﬁnite temperature using a Hubbard–Stratonovich transformation with a two–ﬁeld representation and solve this problem in a static approximation. We argue that temperature dramatically inﬂuence the collinear and spiral magnetic phases, phase separation in the vicinity of half–ﬁlling. The results imply a possible interpretation of unusual behavior of magnetic properties of single–layer cuprates.
Structural Singularities and Local Magnetic Properties of New Nanobiomagnetic Having Polysaccharide Matrix
Authors: Pokatilov V. S. , Konovalova A. O. , Sigov A. S.
Published: June 2012

Structure, valence and magnetic states of iron ions of the nanodispersed magnetite stabilised by a dielectric matrix have been studied by the 57Fe Mössbauer spectroscopy, X - ray and electronic microscopy.
Low-Doped La0.54Ho0.11Sr0.35Mn1-XVxO3 Manganites: Vanadium Influence on Transport Phenomena and Magnetic Properties
Authors: Craus M.L. , Cornei N. , To T.L.
Published: June 2012

Transport phenomena in manganites (ABO3), and indirectly the transition temperature from metallic to insulator state (TMI), can be controlled by hole doping and the average ionic size at A positions (). In agreement with Zener theory, the strength of double exchange is determined by the Mn-O length (dMnO) and Mn-O-Mn angles () of the Mn-O-Mn bonds. We will investigate the influence of substitution of Mn with V on the crystalline structure and transport characteristics in La0.54Ho0.11Sr0.35Mn1-xVxO3 manganites. The samples were prepared by sol-gel method to improve the purity and homogeneity of the samples. By XRD it was established that the samples contain only ABO3 perovskite phases, except the samples with x0.1. The resistance of the samples vs temperature was determined by four probes method. The specific magnetization was obtained by using a Foner type magnetometer, working at 1.4 T, between 77 and 400 K.
Prevalence and socio-demographic factors associated with anaemia in pregnancy in a primary health centre in Rivers State, Nigeria
Authors: Ndukwu Geraldine U. , Dienye Paul O.
Published: June 2012

Background: Anaemia, though a common problem in Nigeria, has not been adequately studied amongst pregnant women in primary health care facilities. Objective: This study is aimed at determining the prevalence of anaemia and sociodemographic factors associated with anaemia in pregnancy in a primary health centre in Rivers State, Nigeria.Methodology: This is a cross-sectional study carried out in a primary health centre. Association between variables was analysed using the Chi-square test.Results: Two hundred and twenty-seven pregnant women whose ages ranged from 16 to 40 years with a mean age of 26.8 ± 4.3 years were recruited for the study. The haemoglobin concentration ranged from 6 g/dL – 15 g/dL with a mean of 10.10 ± 1.27g/dL. A total of 142 (62.6%) participants were anaemic. Anaemia was observed to be least prevalent in women within the extremes of reproductive age (≤ 20 years and 36–40 years). There was no statistically significant association between age, educational level and marital status (p > 0.05). The association of anaemia with social class was statistically significant (p = 0.000). Severe anaemia was not a common finding amongst the patients but it was significantly associated with educational status (p = 0.02) and socio-economic status (p = 0.03).Conclusion: The prevalence of anaemia amongst the pregnant participants in the primary health centre was high. Out of all the socio-demographic characteristics, only socio-economic status was significantly associated with anaemia. It is recommended that the socio-economic status of women should be enhanced in line with the Millennium Development Goals to prevent anaemia and to enhance pregnancy outcomes.
High Order Cubic-Polynomial Interpolation Schemes on Triangular Meshes
Authors: Feng Renzhong
Published: June 2012

The Cubic-Polynomial Interpolation scheme has been developed and applied to many practical simulations. However, it seems the existing Cubic-Polynomial Interpolation scheme are restricted to uniform rectangular meshes. Consequently, this scheme has some limitations to problems in irregular domains. This paper will extend the Cubic-Polynomial Interpolation scheme to triangular meshes by using some spline interpolation techniques. Numerical examples are provided to demonstrate the accuracy of the proposed schemes.
A Numerical Scheme for the Quantum Fokker-Planck-Landau Equation Efficient in the Fluid Regime
Authors: Hu Jingwei , Jin Shi , Yan Bokai
Published: June 2012

We construct an efficient numerical scheme for the quantum Fokker-Planck- Landau (FPL) equation that works uniformly from kinetic to fluid regimes. Such a scheme inevitably needs an implicit discretization of the nonlinear collision operator, which is difficult to invert. Inspired by work [9] we seek a linear operator to penalize the quantum FPL collision term QqFPL in order to remove the stiffness induced by the small Knudsen number. However, there is no suitable simple quantum operator serving the purpose and for this kind of operators one has to solve the complicated quantum Maxwellians (Bose-Einstein or Fermi-Dirac distribution). In this paper, we propose to penalize QqFPL by the "classical" linear Fokker-Planck operator. It is based on the observation that the classical Maxwellian, with the temperature replaced by the internal energy, has the same first five moments as the quantum Maxwellian. Numerical results for Bose and Fermi gases are presented to illustrate the efficiency of the scheme in both fluid and kinetic regimes.
Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) data set
Authors: Jones A. , Walker K. A. , Jin J. J. , Taylor J. R. , Boone C. D. , Bernath P. F. , Brohede S. , Manney G. L. , McLeod S. , Hughes R. , Daffer W. H.
Published: June 2012

Abstract. The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) aboard the Canadian satellite SCISAT (launched in August 2003) was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON) at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC) Chemistry-Climate Model Validation Activity). The ACE-FTS climatological data set is available through the ACE website.
Strongly sheared stratocumulus convection: an observationally based large-eddy simulation study
Authors: Wang S. , Zheng X. , Jiang Q.
Published: June 2012

Abstract. Unusually large wind shears across the inversion in the stratocumulus-topped marine boundary layer (MBL) were frequently observed during VOCALS-REx. To investigate the impact of wind shear on the MBL turbulence structure, a large-eddy simulation (LES) model is used to simulate the strongly sheared MBL observed from Twin-Otter RF 18 on 13 November 2008. The LES simulated turbulence statistics agree in general with those derived from the measurements, with the MBL exhibiting a decoupled structure characterized by an enhanced entrainment and a turbulence intensity minimum just below the clouds. Sensitivity simulations show that the shear forcing tends to reduce the dynamic stability of the inversion, characterized by the bulk (or gradient) Richardson number. This decrease enhances the entrainment mixing, leading to reduced cloud water. Consequently, the turbulence intensity in the MBL is significantly weakened by the intense wind shear. The inversion thickens considerably and the MBL top separates from the cloud top, creating a finite cloud-free sublayer of 10–50 m thickness within the inversion, depending on the Richardson number. The weakened inversion tends to enhance the turbulence buoyant consumption and simultaneously lead to a reduced buoyant production in the cloud layer due to less radiative cooling. These effects may result in a decoupling process that creates the different heating/moistening rates between the cloud and subcloud layer, leading to a two-layered structure in the strongly sheared stratocumulus-topped MBL.
Remote sensing of coccolithophore blooms in selected oceanic regions using the PhytoDOAS method applied to hyper-spectral satellite data
Authors: Sadeghi A. , Dinter T. , Vountas M. , Taylor B. , Altenburg-Soppa M. , Bracher A.
Published: June 2012

Abstract. In this study temporal variations of coccolithophore blooms are investigated using satellite data. Eight years (from 2003 to 2010) of data of SCIAMACHY, a hyper-spectral satellite sensor on-board ENVISAT, were processed by the PhytoDOAS method to monitor the biomass of coccolithophores in three selected regions. These regions are characterized by frequent occurrence of large coccolithophore blooms. The retrieval results, shown as monthly mean time series, were compared to related satellite products, including the total surface phytoplankton, i.e. total chlorophyll a (from GlobColour merged data) and the particulate inorganic carbon (from MODIS-Aqua). The inter-annual variations of the phytoplankton bloom cycles and their maximum monthly mean values have been compared in the three selected regions to the variations of the geophysical parameters: sea-surface temperature (SST), mixed-layer depth (MLD) and surface wind-speed, which are known to affect phytoplankton dynamics. For each region, the anomalies and linear trends of the monitored parameters over the period of this study have been computed. The patterns of total phytoplankton biomass and specific dynamics of coccolithophore chlorophyll a in the selected regions are discussed in relation to other studies. The PhytoDOAS results are consistent with the two other ocean color products and support the reported dependencies of coccolithophore biomass dynamics on the compared geophysical variables. This suggests that PhytoDOAS is a valid method for retrieving coccolithophore biomass and for monitoring its bloom developments in the global oceans. Future applications of time series studies using the PhytoDOAS data set are proposed, also using the new upcoming generations of hyper-spectral satellite sensors with improved spatial resolution.
Nitrogen turnover in a tidal flat sediment: assimilation and dissimilation by bacteria and benthic microalgae
Authors: Dähnke K. , Moneta A. , Veuger B. , Soetaert K. , Middelburg J. J.
Published: June 2012

Abstract. In a short-term (24 h) 15N-labeling experiment, we investigated reactive nitrogen cycling in a tidal flat sediment, focusing on the relative importance of assimilatory versus dissimilatory processes and the role of benthic microalgae therein. 15N-labeled ammonium and nitrate were added separately to homogenized sediment, and 15N was subsequently traced into sediment and dissolved inorganic nitrogen (DIN) pools. Integration of results in a N-cycle model allowed us to quantify rates for the major assimilatory and dissimilatory processes in the sediment. Overall, results indicate that the balance between assimilation and dissimilation in this tidal mudflat was mainly dependent on the nitrogen source. Nitrate was utilized almost exclusively dissimilatory via denitrification, whereas ammonium was rapidly assimilated, with about a quarter of this assimilation due to benthic microalgae (BMA). Benthic microalgae significantly affect assimilation of ammonium, because in the absence of BMA activity the sediments turns from a net ammonium sink to a net source. Nitrification rates were initially very high, but declined rapidly suggesting that nitrification rates are low in undisturbed sediments, and that in a dynamic environment like tidal flats, intense and fast nitrification/denitrification of ammonium is common. The driving mechanisms for assimilation or dissimilation accordingly appear to be ruled to a large extent by external physical forcing, with the entire system being capable of rapid shifts following environmental changes.
Technical Note: Comparison between a direct and the standard, indirect method for dissolved organic nitrogen determination in freshwater environments with high dissolved inorganic nitrogen concentrations
Authors: Graeber D. , Gelbrecht J. , Kronvang B. , Gücker B. , Pusch M. , Zwirnmann E.
Published: June 2012

Abstract. Research on dissolved organic nitrogen (DON) in aquatic systems with high dissolved inorganic nitrogen (DIN, the sum of NO3−, NO2− and NH4+) concentrations is often hampered by high uncertainties of the determined DON concentration. The reason is that DON is determined indirectly as the difference between total dissolved nitrogen (TDN) and DIN. In this standard approach to determine DON concentrations, even small relative measurement errors of the DIN and TDN concentrations propagate into high absolute errors of DON concentrations at high DIN:TDN ratios. To improve the DON measurement accuracy at high DIN:TDN ratios, we investigated the DON measurement accuracy of this standard approach in dependence of DIN:TDN ratio and compared it to the direct measurement of DON by size-exclusion chromatography (SEC). For this, we used standard compounds and natural samples with and without DIN enrichment. We show that for the standard approach, large errors of the determined DON concentrations at DIN:TDN ratios >0.6 occur for both standard compounds and natural samples. In contrast, measurements of DON by SEC always resulted in low errors at high DIN:TDN ratios due to the successful separation of DON from DIN. For SEC, DON recovery rates were 90.7–107.9% for five pure standard compounds and 89–103% for two standard compounds, enriched with DIN. Moreover, SEC resulted in 93–101% recovery rates for DON concentrations of natural samples at a DIN:TDN ratio of 0.8. With 2.5 h of measurement time per sample, SEC is a moderately fast and accurate alternative to the standard approach for the determination of DON concentrations in freshwaters with DIN:TDN ratios >0.6. The direct DON measurement by SEC will enable the scientific community to gather accurate information on DON concentrations, especially in anthropogenically disturbed systems with high DIN concentrations.
A cost-efficient method to assess carbon stocks in tropical peat soil
Authors: Warren M. W. , Kauffman J. B. , Murdiyarso D. , Anshari G. , Hergoualc'h K. , Kurnianto S. , Purbopuspito J. , Gusmayanti E. , Afifudin M. , Rahajoe J. , Alhamd L. , Limin S. , Iswandi A.
Published: June 2012

Abstract. Estimation of soil carbon stocks in tropical wetlands requires costly laboratory analyses and suitable facilities, which are often lacking in developing nations where most tropical wetlands are found. It is therefore beneficial to develop simple yet robust analytical tools to assess soil carbon stocks where financial and technical limitations are common. Here we use published and original data to describe soil carbon density (gC cm−3; Cd) as a function of bulk density (g dry soil cm−3; Bd), which can be used to estimate belowground carbon storage using Bd measurements only. Predicted carbon densities and stocks are compared with those obtained from direct carbon analysis for ten peat swamp forest stands in three national parks of Indonesia. Analysis of soil carbon density and bulk density from the literature indicated a strong linear relationship (Cd = Bd × 0.49 + 4.61, R2 = 0.96, n = 94) for soils with an organic C content >40%. As organic C content decreases, the relationship between Cd and Bd becomes less predictable as soil texture becomes an important determinant of Cd. The equation predicted soil C stocks to within 0.39% to 7.20% of observed values. When original data were included in the analysis, the revised equation: Cd = Bd × 0.48 + 4.28, R2 = 0.96, n = 678 was well within the 95% confidence intervals of the original equation, and tended to decrease Cd estimates slightly. We recommend this last equation for a rapid estimation of soil C stocks for well developed peat soils where C content >40%.
Cryogenic cave carbonate – a new tool for estimation of the Last Glacial permafrost depth of the Central Europe
Authors: Žák K. , Richter D. K. , Filippi M. , Živor R. , Deininger M. , Mangini A. , Scholz D.
Published: June 2012

Abstract. Cryogenic cave carbonate (CCC) represents a specific type of speleothems, whose precipitation is triggered by freezing of mineralized karst water. Coarse-crystalline CCC, which formed during slow freezing of water in cave pools, is known in 20 Central European caves located in Germany, the Czech Republic, Slovakia and Poland. All these caves are situated in an area, which was glacier-free during the Weichselian. Whereas the formation of usual types of speleothems in caves of this region usually ceased during glacials, CCC precipitation was restricted to glacial periods. Since CCC represents a novel, useful paleoclimate proxy, data from Weichselian CCC occurrences in caves in Central Europe were collected, including their C and O stable isotope systematics, U-series ages and depth below the surface. When using only the CCC data from caves with limited cave ventilation, the permafrost depths of the Weichselian can be estimated to be at least 65 m in the lowlands and uplands. An isolated CCC find indicates that Weichselian permafrost penetrated to a depth of at least 285 m in the High Tatra Mts., Slovakia. A model of the formation of coarse-crystalline CCC assumes its formation especially during periods of permafrost thawing. U-series data confirm that permafrost depth changed and CCC precipitation occurred repeatedly in the studied area during Marine Isotope Stages 4, 3 and 2. One important phase of CCC formation related to permafrost thawing occurred between 40 and 21 ka BP, and the last phase of its formation was related to the final permafrost destruction between 17 and 12 ka BP.
Similarity between runoff coefficient and perennial stream density in the Budyko framework
Authors: Wang D. , Wu L.
Published: June 2012

Abstract. Streams are categorized into perennial and temporal streams based on flow durations. Perennial stream is the basic network, and temporal stream (ephemeral or intermittent) is the expanded network. Connection between perennial stream and runoff generation at the mean annual scale exists since one of the hydrologic functions of perennial stream is to deliver runoff. The partitioning of precipitation into runoff and evaporation at the mean annual scale, on the first order, is represented by the Budyko hypothesis which quantifies the ratio of evaporation to precipitation (E/P) as a function of climate aridity index (Ep/P, ratio of potential evaporation to precipitation). In this paper, it is hypothesized that similarity exists between perennial stream density (Dp) and runoff coefficient (Q/P) as a function of climate aridity index, i.e.,   DpDp* (EpP) and   QP   (EpP) where Dp* is a scaling factor and Q is mean annual runoff. To test the hypothesis, perennial stream densities for 185 watersheds in the United States are computed based on the high resolution national hydrography dataset (NHD). The similarity between perennial stream density and runoff coefficient is promising based on the case study watersheds. As a potential application for macroscale hydrological modeling, perennial stream density in ungauged basin can be predicted based on climate aridity index using the complementary Budyko curve.
Groundwater surface water interactions through streambeds and the role of phreatophytes in identifying important recharge zones
Authors: Ahring T. S. , Steward D. R.
Published: June 2012

Abstract. Groundwater and surface water interactions within riparian corridors impact the distribution of phreatophytes that tap into groundwater stores. The changes in canopy area of phreatophytes over time is related to changes in depth to groundwater, distance from a stream or river, and hydrologic soil group. Remote sensing was used to determine the location of trees with predevelopment and post-development aerial photography over the Ogallala Aquifer in the central plains of the United States. It was found that once the depth to groundwater becomes greater than about 3 m, tree populations decrease as depth to water increases. This subsequently limited the extent of phreatophytes to within 700 m of the river. It was also found that phreatophytes have a higher likelihood of growing on hydrologic soil groups with higher saturated hydraulic conductivity. Phreatophytes exist along portions of the Arkansas River corridor where significant decreases in groundwater occurred as long as alluvium exists to create perched conditions where trees survive dry periods. Significant decreases (more that 50%) in canopy cover exists along river segments where groundwater declined by more than 10 m, indicating areas with good hydraulic connectivity between surface water and groundwater. Thus, interpretation of changes in phreatophyte distribution using historical and recent aerial photophaphy is important in delineating zones of enhanced recharge where aquifers might be effectively recharged through diversion of surface water runoff.
Instability mechanisms affecting cultural heritage sites in the Maltese Archipelago
Authors: Gigli G. , Frodella W. , Mugnai F. , Tapete D. , Cigna F. , Fanti R. , Intrieri E. , Lombardi L.
Published: June 2012

Abstract. The superimposition of geological formations with marked contrast in geotechnical properties presents one of the most critical environments for slope instability due to the different response of the materials to the applied disturbances. Moreover, the above-mentioned geological setting is often associated with high risk conditions, since many isolated rock slabs located at a higher altitude than the surrounding countryside have been sites of historical towns or buildings. The purpose of the present paper is to investigate the mechanisms determining instability in rock slabs overlying a soft substratum, with reference to two cultural heritage sites in Malta. Accurate investigations have been carried out to evaluate the geological, geotechnical and geomechanical properties together with the main geomorphological features of the soft clayey substratum and the overlying limestone rock mass. The main instability processes have thus been identified and investigated through kinematic analyses and numerical modeling, combined with a 1992–2001 Persistent Scatterers monitoring of ground displacements. The study constitutes the basis for the subsequent restoration works.
Particle aggregation at the edges of anticyclonic eddies and implications for distribution of biomass
Authors: Samuelsen A. , Hjøllo S. S. , Johannessen J. A. , Patel R.
Published: June 2012

Abstract. Acoustic measurements show that the biomass of zooplankton and mesopelagic fish is redistributed by mesoscale variability and that the signal extends over several hundred meters depth. The mechanisms governing this distribution are not well understood, but influences from both physical (i.e. redistribution) and biological processes (i.e. nutrient transport, primary production, active swimming, etc.) are likely. This study examines how hydrodynamic conditions and basic vertical swimming behavior act to distribute biomass in an anticyclonic eddy. Using an eddy-resolving 2.3 km-resolution physical ocean model as forcing for a particle-tracking module, particles representing passively floating organisms and organisms with vertical swimming behavior are released within an eddy and monitored for 20 to 30 days. The role of hydrodynamic conditions on the distribution of biomass is discussed in relation to the acoustic measurements. Particles released close to the surface tend, in agreement with the observations, to accumulate around the edge of the eddy, whereas particles released at depth gradually become distributed along the isopycnals. After a month they are displaced several hundreds meters in the vertical with the deepest particles found close to the eddy center and the shallowest close to the edge. There is no evidence of aggregation of particles along the eddy rim in the last simulation. The model results points towards a physical mechanism for aggregation at the surface, however biological processes cannot be ruled out using the current modeling tool.
Spatial patterns of North Atlantic Oscillation influence on mass balance variability of European glaciers
Authors: Marzeion B. , Nesje A.
Published: June 2012

Abstract. We present and validate a set of minimal models of glacier mass balance variability. The most skillful model is then applied to reconstruct 7735 individual time series of mass balance variability for all glaciers in the European Alps and Scandinavia. Subsequently, we investigate the influence of atmospheric variability associated with the North Atlantic Oscillation (NAO) on the glaciers' mass balances. We find a spatial coherence in the glaciers' sensitivity to NAO forcing which is caused by regionally similar mechanisms relating the NAO forcing to the mass balance: in southwestern Scandinavia, winter precipitation causes a correlation of mass balances with the NAO. In northern Scandinavia, temperature anomalies outside the core winter season cause an anti-correlation between NAO and mass balances. In the western Alps, both temperature and winter precipitation anomalies lead to a weak anti-correlation of mass balances with the NAO, while in the eastern Alps, the influences of winter precipitation and temperature anomalies tend to cancel each other, and only on the southern side a slight anti-correlation of mass balances with the NAO prevails.
Working Memory Capacity and Individual Differences in the Making of Reinstatement and Elaborative Inferences
Authors: Barreyro Juan Pablo , Cevasco Jazmín , Burín Débora , Marotto Carlos Molinari
Published: June 2012

This study investigated the role of working memory capacity on the making of reinstatement and causal elaborative inferences during the reading of natural texts. In order to determine participants' working memory capacity, they were asked to take the reading span task before they took part in the study. Those participants that were identified as high or low working memory capacity readers were asked to perform a lexical decision task in two conditions: pre-inference and inference. In the pre-inference condition, target words representing reinstatement or causal elaborative inferences were presented immediately before the sentences that were predicted to prompt them. In the inference condition, the target words were presented immediately after the sentences that were predicted to prompt the inferences. Results indicated that, for the high working memory capacity readers, lexical decision times were faster at the inference compared to the pre-inference locations for both types of inferences. In the case of low working capacity readers, lexical decision times were faster at the inference compared to the pre-inference locations only for reinstatement inferences. These findings suggest that working memory capacity plays a role in the making of causal inferences during the comprehension of natural texts.
Acoustic Markers Associated with Impairment in Language Processing in Alzheimer's Disease
Authors: Meilán Juan J. G. , Martínez-Sánchez Francisco , Carro Juan , Sánchez José A. , Pérez Enrique
Published: June 2012

This study broaches in a novel way the analysis of cognitive impairment characteristic of the early stages of Alzheimer's Disease (AD). Specifically, we attempt to determine the acoustic speech parameters that are sensitive to the onset of the disease, and their association with the language deficit characteristic of AD. Speech analysis was carried out on 21 elderly patients with AD using Praat software, which analyzes the acoustic components of speech. The data obtained were subjected to stepwise regression, using the overall scores obtained in the test as the criterion variable, and the scores on the frequency, amplitude and periodicity variables as predictors of performance. We found that the percentage of voiceless segments explains a significant portion of the variance in the overall scores obtained in the neuropsychological test. This component seems to be related mainly to the patient's ability in phonological fluency. This finding could permit the creation of a diagnostic test for AD through analysis of the acoustic speech parameters at very low cost in terms of both time and resources.
Differential Diagnosis between Apraxia and Dysarthria Based on Acoustic Analysis
Authors: Melle Natalia , Gallego Carlos
Published: June 2012

Acoustic analysis provides objective quantitative measures of speech that enable a comprehensive and accurate understanding of motor disorders and complement the traditional measures. This paper aims to distinguish between normal and pathological speech, more specifically between apraxia of speech and spastic dysarthria in native Spanish speaking patients using acoustic parameters. Participants (4 aphasic with apraxia of speech, 4 with spastic dysarthria, and 15 without speech disorders) performed three different tasks: repeating the syllable sequence [pa-ta-ka], repeating the isolated syllable [pa] and repeating the vowel sequence [i-u]. The results showed that the normative values of motor control, in general, coincide with those obtained in previous research on native English speakers. They also show that damage to motor control processes results in a decrease in the rate of alternating and sequential movements and an increase in the inter-syllabic time for both types of movements. A subset of the acoustic parameters analyzed, those that measure motor planning processes, enable differentiation between normal population and apraxic and dysarthric patients, and between the latter. The differences between the pathological groups support the distinction between motor planning and motor programming as described by van der Merwe's model of sensorimotor processing (1997).
The Effects of Base Frequency and Affix Productivity in Spanish
Authors: López-Villaseñor Miguel Lázaro
Published: June 2012

In this study we present the results of a lexical decision experiment where the variables manipulated are Base frequency and Affix productivity. The results show significant main effects for both variables for the first time in Spanish, as well as for the interaction between the two. However, pair analysis shows that the Base Frequency effect is not significant when the Affix Productivity is low, while the Affix Productivity effect is produced regardless of the Base Frequency. The results for the main effects show a morphological representation in the lexicon, whilst the results of pair comparisons suggest a different representation of stems and affixes in the lexicon. These results support the idea that complex words incorporating unproductive affixes are processed differently from words incorporating productive affixes. The results are finally explained in terms of a hierarchical model of morphological processing.
Number Processing and Calculation in Brazilian Children Aged 7-12 Years
Authors: Santos Flávia Heloísa Dos , Da Silva Paulo Adilson , Ribeiro Fabiana Silva , Dias Ana Luiza Ribeiro Pereira , Frigério Michele Cândida , Dellatolas Georges , von Aster Michael
Published: June 2012

Numerical cognition is based on two components - number processing and calculation. Its development is influenced by biological, cognitive, educational, and cultural factors. The objectives of the present study were to: i) assess number processing and calculation in Brazilian children aged 7-12 years from public schools using the Zareki-R (Battery of neuropsychological tests for number processing and calculation in children, Revised; von Aster & Dellatolas, 2006) in order to obtain normative data for Portuguese speakers; ii) identify how environment, age, and gender influences the development of these mathematical skills; iii) investigate the construct validity of the Zareki-R by the contrast with the Arithmetic subtest of WISC-III. The sample included 172 children, both genders, divided in two groups: urban (N= 119) and rural (N= 53) assessed by the Zareki-R. Rural children presented lower scores in one aspect of number processing; children aged 7-8 years demonstrated an inferior global score than older; boys presented a superior performance in both number processing and calculation. Construct validity of Zareki-R was demonstrated by high to moderate correlations with Arithmetic subtest of WISC-III. The Zareki-R therefore is a suitable instrument to assess the development of mathematical skills, which is influenced by factors such as environment, age, and gender.
A Comparative Study of General Intelligence in Spanish and Moroccan Samples
Authors: Díaz Amelia , Sellami Khadija , Infanzón Eugenia , Lanzón Teresa , Lynn Richard
Published: June 2012

The aim of this study is to fill a gap in intelligence research by presenting data for the average IQ in Morocco and for a comparable sample in Spain. Adult samples were administered theRaven Standard Progressive Matrices (SPM)(Raven, Court, & Raven, 2001) and scored for the total test and for the three sub-factors of gestalt continuation, verbal-analytical reasoning and visuospatial ability identified by Lynn, Allik, and Irwing (2004). The total test and the three factors have shown satisfactory reliability. Our results for the Moroccan sample show significant relationship between general intelligence factor, gestalt continuation and visuospatial ability with education level and income. Conversely, these variables have been shown to be independent for the Spanish sample. This sample obtained significantly higher scores for the four factors assessed than the Moroccan one. These differences have been found also comparing samples with the same education levels. Finally, the errors percentage for Moroccans has been higher than for Spaniards in all the items, suggesting that the level of difficulty was higher for the Moroccan sample.
The Benefits of Chess for the Intellectual and Social-Emotional Enrichment in Schoolchildren
Authors: Aciego Ramón , García Lorena , Betancort Moisés
Published: June 2012

This paper examines the benefits of regularly playing chess for the intellectual and social-emotional enrichment of a group of 170 schoolchildren from 6-16 years old. It is based on a quasi-experimental design, where the independent variable was the extracurricular activity of chess (n = 170) versus extracurricular activities of soccer or basketball (n = 60). The dependent variable was intellectual and socio-affective competence, which was measured by an IQ test (WISC-R), a self-report test (TAMAI) and a hetero-report questionnaire (teacher-tutor's criterion) applied at the beginning and the end of the academic year. In contrast to the comparison group, it was found that chess improves cognitive abilities, coping and problem-solving capacity, and even socioaffective development of children and adolescents who practice it. The results are modulated, particularly in the area socioaffective, by the personal profile of students who choose practice this activity.
Variables Associated with the Nature of Sexual Abuse to Minors
Authors: Duarte José Cantón , Arboleda Mª Rosario Cortés , Cantón-Cortés David
Published: June 2012

This study analyzes the prevalence and characteristics of childhood and adolescence sexual abuse suffered by a sample of university students, as well as the variables associated with the nature of abuse. Participants anonymously completed the Questionnaire on Child Sexual Abuse, in order to obtain information about experience of sexual abuse. Of a total of 2,375 students, 289 (12.2%) declared having suffered sexual abuse before the age of 18. The invasiveness, continuity, and severity of abuse was related to the location where the abuse took place (the more severe cases were committed in the homes of the victim and perpetrator) and to the circumstances of abuse (relationships with partners/at a party or while caring for a child predicted more severe abuse). The age of the victim (preschool) and an intrafamilial relationship between victim and perpetrator were also related to more invasive, continuous, and severe sexual abuse. The knowledge of characteristics of perpetrator and victim and the context in which sexual abuse occurs can help to better comprehend the nature and correlates of sexual abuse. The results of the present study may contribute to the design of programs for the prevention of sexual abuse to minors.
Parental Socialization Styles, Parents' Educational Level, and Sexist Attitudes in Adolescence
Authors: Garaigordobil Maite , Aliri Jone
Published: June 2012

The aims of this study were to analyze the differences in the mothers' and fathers' socialization styles depending on their children's sex; whether there are differences in hostile, benevolent, and ambivalent sexism, and neosexism as a function of both parents' socialization styles; and whether the parents' educational level affects their level of sexism and their children's sexism. The sample included 1,455 adolescents and their parents (764 mothers and 648 fathers). The results showed no differences in the socialization style of the father with his children's sexism, but the mother used a more authoritarian style with her daughters. The parents' socialization style had little influence on their children's sexism, although it had a higher impact on the sons' sexism. The father's style had less influence than the mother's on their sons' sexism, and it had no influence on their daughters' sexism. The indulgent style of both parents had the highest relation with a low level of sexism. Moreover, a negative correlation was found between the parents' educational level and their level of sexism, as well as between the mother's educational level and her daughters' sexism. To conclude, the indulgent style and the mother's high educational level promote fewer sexist attitudes.
Self-Recognition and Self-Regulation: The Relationship with Socialization Trajectories and Children's Sex
Authors: Seidl-de-Moura Maria Lucia , Bandeira Tatiana Targino Alves , de Marca Renata Gomes da Costa , Pessôa Luciana Fontes , Mendes Deise Maria Leal Fernandes , Vieira Mauro Luis , Kobarg Ana Paula Ribeiro
Published: June 2012

The initial process of self development involves interaction with others and the establishment of relationships taking different paths depending on the socio-cultural context. Self-recognition and self-regulation are considered manifestations of this development between 18 and 24 months of age. This study aimed at analyzing the relationship between these two aspects, maternal beliefs about autonomy and relatedness, as well as identifying differences between boys and girls in this developmental stage. Participants were 94 mothers of different educational levels and their children of 17-22 months of age in two Brazilian cities. Socialization Goals Inventory and Parental Practices in the First Year Inventory were used to collect data on mothers' beliefs. Children performed tasks related to self-recognition (the mirror test) and self-regulation (compliance to requests). The group of mothers studied valued both autonomy and interdependence. Children's responses are consistent with a perspective of relational autonomy, which value both independence and interdependence. Differences were found in relation to sex in both self-recognition and self-regulation, and baby girls showed superior performance than boys in both tasks.
Self-Perceptions, Self-Worth and Sport Participation in Adolescents
Authors: Balaguer Isabel , Atienza Francisco L. , Duda Joan L.
Published: June 2012

The purpose of this study was to study the associations between specific self-perceptions and global self-worth with different frequency levels of sport participation among Spanish boys and girls adolescents. Students (457 boys and 460 girls) completed the Self Perception Profile for Children (Harter, 1985) and items assessing sport engagement from The Health Behavior in School Children Questionnaire (Wold, 1995). Results showed that some specific dimensions of self-perception were related to different frequency of sport participation whereas overall judgments of self-worth did not. Specifically, for boys and girls, higher levels of sport participation were positively associated to Athletic Competence, and for boys were also associated with Physical Appearance and Social Acceptance. The potential implications of domain specific socialisation processes on the configuration of self-perceptions are highlighted.
Elucidating the Role of Recovery Experiences in the Job Demands-Resources Model
Authors: Moreno-Jiménez Bernardo , Rodríguez-Muñoz Alfredo , Sanz-Vergel Ana Isabel , Garrosa Eva
Published: June 2012

Based on the Job Demands-Resources (JD-R) model, the current study examined the moderating role of recovery experiences (i.e., psychological detachment from work, relaxation, mastery experiences, and control over leisure time) on the relationship between one job demand (i.e., role conflict) and work-and health-related outcomes. Results from our sample of 990 employees from Spain showed that psychological detachment from work and relaxation buffered the negative impact of role conflict on some of the proposed outcomes. Contrary to our expectations, we did not find significant results for mastery and control regarding moderating effects. Overall, findings suggest a differential pattern of the recovery experiences in the health impairment process proposed by the JD-R model.