bluuebunny/crossref_metadata_2025 huggingface dataset:
New Directions for Research on Intimate Partner Violence and Children
Authors: Levendosky Alytia A. , Bogat G. Anne , von Eye Alexander
Published: March 2007

This article provides an overview to the Special Section in this issue on intimate partner violence (IPV) and children. The argument is made that the field needs to pay more attention to issues of theory, definitions, and methodology. The contributors to the Special Section each make a unique contribution to one of these topics. Their articles document that increased focus on definition and theory, methodologies involving laboratory studies, data collection at multiple time-points, person-oriented approaches, and diverse samples of children exposed to IPV will begin to increase the research sophistication of the field. We argue that the field needs comparability of definitions for the same/similar phenomena under investigation, more sophisticated, testable hypotheses, a better understanding of the short- and long-term consequences of exposure to IPV, and, finally, a more refined picture of the mechanisms by which exposure to IPV affects particular children.
“It Does Affect Me”
Authors: Baldry Anna C.
Published: March 2007

Aggressive and delinquent behaviors in preadolescents may be indicators of problems suffered at home from direct child abuse by one or both parents or indirect abuse, such as exposure to domestic violence. A total of 532 Italian preadolescents recruited in their schools took part in this study. They completed a self-report questionnaire measuring direct child abuse from mothers and fathers, exposure to mother-to-father and father-to-mother violence, and externalizing delinquent and aggressive behaviors. Results indicated high levels of delinquent and aggressive behavior, compared to normative data, as well as high levels of reported direct and indirect family abuse. Hierarchical regression analysis indicated an independent significant effect for gender, mother- to-father violence, and both paternal child abuse and maternal child abuse. Discussion includes the importance of addressing externalizing problems of adolescents as indicators of family-related abuse, which may require multiple interventions and coordination between different agencies that work with children.
Co-Occurrence of Child and Partner Maltreatment
Authors: Knickerbocker Lauren , Heyman Richard E. , Smith Slep Amy M. , Jouriles Ernest N. , McDonald Renee
Published: March 2007

This paper addresses issues in the literature regarding the co-occurrence of partner and child physical maltreatment in the United States and in Europe. Design issues including operationalizations, representativeness of samples, data collection methods, and reference periods are discussed in the context of prevalence studies. Next, possible explanations for the pervasiveness of co-occurring maltreatment are explored with an emphasis on theoretical models and mechanisms of co-occurrence. Finally, we offer assessment implications for clinicians and agencies dealing with partner and child maltreatment.
Domestic Abuse and Children's Health in the Canary Islands, Spain
Authors: Matud M. Pilar
Published: March 2007

This study analyzed the association between domestic partner abuse and children's health. The sample consisted of 420 abused women with at least one child, for a total of 406 female children and 504 male children in 420 households. The women reported that one or more of their children had psychological problems in 27.4% of the cases, 13.6% reported physical health problems, and 7.6% reported both psychological and physical health problems. Externalizing problems were reported most frequently (in 11.7% of the children), while internalizing problems were reported in 5.6% of the children. A greater percentage of children with psychological and physical health problems was found in families in which the abusive partner was also abusive toward the children. We found better mental health in children whose mothers did not abuse them. Women whose children did not exhibit physical or mental health problems were younger, had suffered fewer years of abuse, and had fewer children than the women whose children exhibited health problems.
Abusive Men's Use of Children to Control Their Partners and Ex-Partners
Authors: Beeble Marisa L. , Bybee Deborah , Sullivan Cris M.
Published: March 2007

While research has found that millions of children in the United States are exposed to their mothers being battered, and that many are themselves abused as well, little is known about the ways in which children are used by abusers to manipulate or harm their mothers. Anecdotal evidence suggests that perpetrators use children in a variety of ways to control and harm women; however, no studies to date have empirically examined the extent of this occurring. Therefore, the current study examined the extent to which survivors of abuse experienced this, as well as the conditions under which it occurred. Interviews were conducted with 156 women who had experienced recent intimate partner violence. Each of these women had at least one child between the ages of 5 and 12. Most women (88%) reported that their assailants had used their children against them in varying ways. Multiple variables were found to be related to this occurring, including the relationship between the assailant and the children, the extent of physical and emotional abuse used by the abuser against the woman, and the assailant's court-ordered visitation status. Findings point toward the complex situational conditions by which assailants use the children of their partners or ex-partners to continue the abuse, and the need for a great deal more research in this area.
Variations in Parenting Stress in African-American Battered Women
Authors: Hughes Honore M. , Huth-Bocks Alissa C.
Published: March 2007

The negative consequences of children's exposure to intimate partner violence (IPV) have been well documented; however, less is known about the effects of contextual factors such as parenting stress, parenting behaviors, and mothers' psychological functioning on exposed children. A total of 172 African-American mothers and their children (4 to 12 years of age) were recruited from battered women's shelters for the present study. Mothers filled out questionnaires assessing family violence, family contextual variables, and children's outcomes, and children reported on their own depressive symptoms. Results from a cluster analysis indicated substantial variability in women's experiences of parenting stress with regard to both type and quantity. Across each of the six clusters, women significantly differed in parenting behaviors and general psychological distress, and their children varied concomitantly in severity of internalizing and externalizing problems. These patterns suggest the need for individualized interventions, with a particular focus on parenting stress, to better serve the needs of women and children experiencing IPV.
Religious People and Paranormal Believers
Authors: Aarnio Kia , Lindeman Marjaana
Published: March 2007

This study aimed at clarifying the relationship between religious and paranormal beliefs, on which previous studies have yielded varying results. It was examined whether the relationship varies by the level of religiousness, and individual differences between religious and paranormal believers and sceptics were compared. Finnish participants (N = 3261) filled in an Internet-based questionnaire. The results showed that the relationship between religious and paranormal beliefs was positive among paranormal believers and sceptics but negative among religious people. High intuitive thinking, low analytical thinking, mystical experiences, and close others' positive attitude toward the supernatural distinguished both kinds of believers from the sceptics, while conservation and self-transcendence values distinguished religious people from paranormal believers.
Structural Modeling of Generalized Prejudice
Authors: Bäckström Martin , Björklund Fredrik
Published: March 2007

Structural equation modeling on questionnaire data showed that prejudice toward different target groups can be represented in terms of a general prejudice factor. Distinction of classical and modern prejudice only increased model fit marginally. In two separate samples (paper and pencil vs. Internet) several structural models of the relationship between key individual difference variables and prejudice were tested, revealing highly similar results. Social dominance orientation, empathy, and right-wing authoritarianism had direct effects on generalized prejudice. The effect of participant sex on generalized prejudice, where the men scored higher, was largely mediated by empathy. The benefit of including empathy in structural models of prejudice is emphasized.
Visualizing Multivariate Dependencies with Association Chain Graphs
Authors: Höfler Michael , Brückl Tanja , Bittner Antje , Lieb Roselind
Published: March 2007

In a recent paper, a new type of graph to visualize the results from graphical models was proposed. Association chain graphs (ACGs) provide a richer visualization than conventional graphs (directed acyclic and recursive regression graphs) if the data can be described with only a small number of parameters. ACGs display not only which associations reach statistical significance, but also the magnitude of associations (confidence intervals for statistical main effects) as the contrast color to the background color of the graph. In this paper, the ACG visualization is extended especially for the case where all variables are binary by illustrating their relative frequencies. This shows the degrees of associations not only on the individual (as expressed by odds ratios or other indexes of association) but also on the community level. We applied the approach to an extensive example of birth and childhood factors for the onset of affective mental disorders using data from the EDSP (Early Developmental Stages of Psychopathology) Study.
Geostrophic circulation patterns in the northeastern Adriatic Sea and the effects of air‐sea coupling: May–September 2003
Authors: Lyons Daniel M. , Supić Nastjenjka , Smodlaka Nenad
Published: March 2007

CTD data were collected weekly during 20 cruises from May to September 2003 over a 19 station grid in a coastal region of the northeastern Adriatic Sea as part of the Adriatic Sea Integrated Coastal Areas and River Basin Management System Pilot Project (ADRICOSM). Relative geostrophic velocities indicated fine scale circulation patterns in the area consisting of two pronounced circulation cells, of cyclonic and anticyclonic character, and that were present in the area for most of the investigated period. These motions were induced primarily by spatial variations in the temperature field and may be strengthened during episodes of very strong northeasterly bora wind, when the investigated region is not heated (cooled) uniformly.
Analysis and modeling of solute transport dynamics by breakdown coefficients and random cascades
Authors: Olsson Jonas , Persson Magnus , Jinno Kenji
Published: March 2007

The small‐scale variability and scaling properties of solute transport dynamics were investigated by laboratory experiments. Dye‐stained water was applied at a constant flux in a Plexiglas Hele‐Shaw cell filled with soil material, and the transport process was registered by digital photographs of the cell front, producing a very high resolution in both time (minutes) and space (millimeters). The experiments comprised different cell materials (uniform and natural sand) and different water fluxes. Scaling properties of vertically integrated dye mass distributions were analyzed and modeled using so‐called breakdown coefficients (BDCs), which represent the multiplicative weights in a microcanonical random cascade process. The pdfs of BDCs varied with scale, indicating self‐affine scaling, and were accurately approximated by beta distributions with a scaling parameter. Two versions of BDC‐based random cascade models were used to simulate mass distributions at different time steps. The results support the applicability of random cascade models to subsurface transport processes.
New spatial Mg/Ca‐temperature calibrations for three Arctic, benthic foraminifera and reconstruction of north Iceland shelf temperature for the past 4000 years
Authors: Kristjánsdóttir G. B. , Lea D. W. , Jennings A. E. , Pak D. K. , Belanger C.
Published: March 2007

We have developed cold‐end Mg/Ca‐temperature calibrations for three common Arctic benthic foraminifera, Islandiella norcrossi/helenae, Melonis barleeanus, and Cassidulina neoteretis, and compare the three calibrations in a late Holocene downcore record (0–4000 cal yr B.P.). The calibration and downcore trends for the three Arctic species extend the observation that Mg incorporation into benthic foraminifera is species specific. For the calibration we use a set of CTD casts, bottom water δ18Oseawater measurements, and surface grab‐samples collected from the Iceland margin (cruise B997) and the Greenland margin (cruise BS1191). Water depth of sites used ranges from 165 to 656 m, while spatial bottom temperature ranges from 0 to 7°C. Mg/Ca values ranged from 1.02 to 1.47 for I. norcrossi/helenae, 0.64 to 2.21 for M. barleeanus, and 0.93 to 1.38 mmol/mol for C. neoteretis. We calibrated Mg/Ca content against isotopic calcification temperature (calculated using T = 16.9 − 4.0*(δ18Ocalcite corrected for vital effect − δ18Oseawater)). Exponential calibrations for the three species are as follows: I. norcrossi/helenae Mg/Ca = 1.051 ± 0.03 * exp(0.060 ± 0.011 * T), M. barleeanus Mg/Ca = 0.658 ± 0.07 * exp(0.137 ± 0.020 * T), and C. neoteretis Mg/Ca = 0.864 ± 0.07 * exp(0.082 ± 0.020 * T). On the basis of Mg/Ca in these benthic species the downcore record from core MD99‐2269 is reconstructed. Bottom temperature values are interpreted to reflect variable inflow of Atlantic and Arctic water to the north Iceland shelf during the last 4000 cal yr B.P. All three reconstructions show a decline by 0.1°C per century from circa 1500‐0 cal yr B.P., which coincides with an increase in Arctic benthic foraminifera abundances and a rise in sea ice proxies in the same core. Intriguingly, C. neoteretis diverges periodically to higher average temperature (Atlantic water conditions) than shown by M. barleeanus or I. norcrossi/helenae (which both show Arctic water temperature) circa 1500–4000 cal yr B.P.
Image‐based measurement of flux variation in distal regions of active lava flows
Authors: James M. R. , Pinkerton H. , Robson S.
Published: March 2007

Understanding the processes involved with the advance of lava flows is critical for improving hazard assessments at many volcanoes. Here, we describe the application of computer vision and oblique photogrammetric techniques to visible and thermal images of active 'a'ā flows in order to investigate distal flow processes at Mount Etna, Sicily. Photogrammetric surveys were carried out to produce repeated topographic data sets for calculation of volumetric lava flux at the flow‐fronts. Velocity profiles from a distal channel were obtained by rectification of a thermal image sequence and are used to investigate the rheological properties of the lava. Significant variations of the magma flux were observed, and pulses of increased flux arrived within the flow‐front region on timescales of several hours. The pulses are believed to be the distal result of more frequent flux changes observed in the vent region. Hence they reflect the importance of flow processes which are believed to cause the coalescence of flux pulses along the channel system as well as short‐period variations in effusion rate. In considering advance processes for the individual flow‐fronts, it must be assumed that they were fed by a highly unsteady flux, which was volumetrically at least an order of magnitude lower than that observed near the vent.
Microstructure measurements in the mid‐depth waters of the North Pacific
Authors: Nagasawa Maki , Hibiya Toshiyuki , Yokota Kanako , Tanaka Yuki , Takagi Shogo
Published: March 2007

Microstructure measurements from the surface down to maximum depths of ∼2000 m were carried out at 28 locations in the interior of the North Pacific. Special attention was directed to the diapycnal diffusivities Kρ in the significant generation regions of the semidiurnal internal tide such as the Aleutian Ridge, the Hawaiian Ridge, and the Izu‐Ogasawara Ridge. In the profiles obtained near the Aleutian Ridge, only a few turbulent patches with ɛ ≥ 10−9 Wkg−1 were detected and Kρ was generally less than 10−5 m2s−1. In the profiles obtained near the Hawaiian Ridge, many turbulent patches with ɛ ≥ 10−9 Wkg−1 were observed, although Kρ was generally of the order of 10−5 m2s−1. Along the Izu‐Ogasawara Trough running in parallel with the Izu‐Ogasawara Ridge, in contrast, remarkably intense turbulent mixing (ɛ ∼ 10−8 Wkg−1, Kρ = 10−4 ∼ 10−3 m2s−1) was common throughout the observed water depth.
Climate change uncertainty for daily minimum and maximum temperatures: A model inter‐comparison
Authors: Lobell David B. , Bonfils Céline , Duffy Philip B.
Published: March 2007

Several impacts of climate change may depend more on changes in mean daily minimum (Tmin) or maximum (Tmax) temperatures than daily averages. To evaluate uncertainties in these variables, we compared projections of Tmin and Tmax changes by 2046–2065 for 12 climate models under an A2 emission scenario. Average modeled changes in Tmin were similar to those for Tmax, with slightly greater increases in Tmin consistent with historical trends exhibiting a reduction in diurnal temperature ranges. In contrast, the inter‐model variability of Tmin and Tmax projections exhibited substantial differences. For example, inter‐model standard deviations of June–August Tmax changes were more than 50% greater than for Tmin throughout much of North America, Europe, and Asia. Model differences in cloud changes, which exert relatively greater influence on Tmax during summer and Tmin during winter, were identified as the main source of uncertainty disparities. These results highlight the importance of considering separately projections for Tmax and Tmin when assessing climate change impacts, even in cases where average projected changes are similar. In addition, impacts that are most sensitive to summertime Tmin or wintertime Tmax may be more predictable than suggested by analyses using only projections of daily average temperatures.
Excitation of microseisms
Authors: Tanimoto Toshiro
Published: March 2007

Excitation of microseisms is generally considered to be due to pressure change at ocean bottom, for which Longuet‐Higgins derived his celebrated formula in 1950. Use of this formula is an approximation, however. Comparison with a more rigorous normal‐mode formula shows that this conventional approach is acceptable for ocean depths less than 1 km but fails in deep oceans. On the other hand, there seems to be a multitude of evidence that source region for double‐frequency microseim is near the coast and thus is generally in shallow water. An evidence from buoy data for nonlinearity in ocean waves is presented to support this view. If a source region is in shallow water, use of the Longuet‐Higgins pressure formula at ocean bottom for the excitation of microseisms is justified, although one should pay attention to ocean depths very carefully.
Baroclinic wave packets in an extended quasigeostrophic two‐layer model
Authors: Yang Wenchang , Nie Ji , Lin Pu , Tan Benkui
Published: March 2007

An extended quasigeostrophic two‐layer model including nonlinear Ekman pumping and nonlinear interface perturbation is used to numerically study the formation and maintenance of baroclinic wave packets. With an initial zonal jet flow of north–south symmetry and small random initial perturbations wave packets of finite amplitude are produced and maintained with an equilibrated wave packet‐zonal flow system exhibiting simultaneously downstream‐upstream asymmetry and north–south asymmetry, the later of which has not been observed in the past simple quasigeostrophic two‐layer modeling studies. The northern upstream part of the wave packets is stronger than its southern upstream counterpart and therefore the peak of time‐and‐zonal‐average eddy kinetic energy associated with the wave packets is shifted poleward while the peak of the time‐mean zonal jet flow is shifted equatorward, which is in agreement with the observations.
Electromagnetic Green's functions retrieval by cross‐correlation and cross‐convolution in media with losses
Authors: Slob Evert , Wapenaar Kees
Published: March 2007

It is shown that the electromagnetic Green's functions of any linear medium with arbitrary heterogeneity can be obtained from the cross‐correlation, or the cross‐convolution, of two recordings at different receiver locations in an open system. Existing representations are known for cross‐correlations where time‐reversal invariance is exploited and hence they are considered in lossless media. We show here that the cross‐correlation type representations are exact in a configuration with sources on a closed boundary and the medium has non‐zero loss terms only outside this boundary. Furthermore, we show that for cross‐convolution representations the loss mechanisms may exist anywhere in space. Many sources of electromagnetic signals exist in the atmosphere and in populated areas, and these can be used in a large variety of practical passive applications exploiting eddy current or electromagnetic wave techniques.
Potential contribution of topography‐driven regional groundwater flow to fractal stream chemistry: Residence time distribution analysis of Tóth flow
Authors: Cardenas M. Bayani
Published: March 2007

Groundwater and surface water are interconnected. Tóth's analysis of topography‐driven groundwater flow, presumably exiting in lakes or streams, is one of the first illustrations of this connection. Recently, fractal behavior in time‐series observations of stream chemistry, implying a power‐law residence time distribution (PLRTD) has been attributed to heterogeneity in subsurface flow paths and mass exchange processes. We show through numerical simulations that topography‐driven groundwater flow, i.e., Tóth flow, and transport under homogeneous aquifer conditions results in PLRTDs and may therefore contribute to fractal behavior in surface water chemistry. For the first time, PLRTDs are explained with a purely physical basis. Heterogeneity, accounted for by a large dispersivity value, makes the PLRTD more pronounced and persistent. Late‐time arrival of solutes from surrounding watersheds results in multi‐modality in the RTD, but these late peaks also follow a PLRTD after arrival.
A comparison of annual vertical crustal displacements from GPS and Gravity Recovery and Climate Experiment (GRACE) over Europe
Authors: van Dam T. , Wahr J. , Lavallée David
Published: March 2007

We compare approximately 3 years of GPS height residuals (with respect to the International Terrestrial Reference Frame) with predictions of vertical surface displacements derived from the Gravity Recovery and Climate Experiment (GRACE) gravity fields for stations in Europe. An annual signal fit to the residual monthly heights, corrected for atmospheric pressure and barotropic ocean loading effects, should primarily represent surface displacements due to long‐wavelength variations in water storage. A comparison of the annual height signal from GPS and GRACE over Europe indicates that at most sites, the annual signals do not agree in amplitude or phase. We find that unlike the annual signal predicted from GRACE, the annual signal in the GPS heights is not coherent over the region, displaying significant variability from site to site. Confidence in the GRACE data and the unlikely possibility of large‐amplitude small‐scale features in the load field not captured by the GRACE data leads us to conclude that some of the discrepancy between the GPS and GRACE observations is due to technique errors in the GPS data processing. This is evidenced by the fact that the disagreement between GPS and GRACE is largest at coastal sites, where mismodeling of the semidiurnal ocean tidal loading signal can result in spurious annual signals.
Ground motion measurement in the Lake Mead area, Nevada, by differential synthetic aperture radar interferometry time series analysis: Probing the lithosphere rheological structure
Authors: Cavalié O. , Doin M.‐P. , Lasserre C. , Briole P.
Published: March 2007

We measure ground motion around the Lake Mead, Nevada, using synthetic aperture radar interferometry. The lake water level has fluctuated through time since impoundment in 1935. To quantify the deformation due to water level variations over the past decade, and to constrain the crust and mantle rheological parameters in the lake area, we analyze 241 interferograms based on 43 ERS images acquired between 1992 and 2002. All interferograms have a high coherence due to arid conditions. Most of them show strong atmospheric artefacts. Tropospheric phase delays are estimated and corrected for each interferogram by analyzing the phase/elevation correlation. Corrections are validated using data from the ERA40 global atmospheric reanalysis. Corrected interferograms are inverted pixel by pixel to solve for the time series of ground motion in the lake area. Temporal smoothing is added to reduce random atmospheric artefacts. The observed deformation is nonlinear in time and spreads over a 50 × 50 km2 area. We observe a 16 mm subsidence between 1995 and 1998 due to an 11 m water level increase, followed by an uplift due to the water level drop after 2000. We model the deformation, taking into account the loading history of the lake since 1935. A simple elastic model with parameters constrained by seismic wave velocities does not explain the amplitude of the observed motion. The two‐layer viscoelastic model proposed by Kaufmann and Amelung (2000), with a mantle viscosity of 1018 Pa s, adjusts well the data amplitude and its spatiotemporal shape.
Temperature and dynamics of degassing at Stromboli
Authors: Harris Andrew , Ripepe Maurizio
Published: March 2007

Between 1999 and 2004 we deployed a series of thermal infrared experiments at Stromboli volcano (Italy) to thermally define the dynamics of gas puffing. These experiments involved targeting degassing vents with thermal infrared thermometers and thermal imagers from a distance of ∼300 m. The data showed that puffs involved a short‐lived gas thrust phase (velocities up to ∼20 m/s) followed by a dominant phase of buoyant rise with constant ascent velocities (∼7 m/s), until cooling caused the puff to stall and disperse. The puff could best be described as a starting plume that rapidly developed into a thermal. Ascent velocities, puff volumes and frequencies were extremely stable over the 6‐year‐long study period, typically being 10 ± 5 m/s, 50–190 m3 per burst and 0.5–1 Hz, respectively. These volumes convert to puff masses of 10–40 kg and give a total gas flux of 7–26 kg/s. Although stable at the system as a whole, at a single vent, gas puffing showed short‐term variation and instability. Gas puffing would wax and wane at individual vents, shifting to other linked vents so that for the system has a whole, puffing activity was maintained. Variations in vent temperature can thus be tied to variations in gas flux, where termination of gas puff activity (a reduction in the flux) at a particular vent results in decreased vent temperature. We suggest that gas puffing is related to a rapid and repeated release (bursting) of gas slugs at the head of the magma column, at a rate of one every 1–2 s. Released gas packets then ascend the empty conduit section to be emitted as the puffing plume. This style of degassing activity persists between Strombolian explosions and operates alongside passive degassing; but has a very different source mechanism. It appears to represent a highly stable and repetitive, but extremely mild, stream of explosive bursts. This style of nonpassive degassing may account for up to 45% of Stromboli's total gas flux.
Models of ice melting and edifice growth at the onset of subglacial basaltic eruptions
Authors: Tuffen Hugh
Published: March 2007

Models of the early stages of basaltic eruptions beneath temperate glaciers are presented that consider the evolving sizes of volcanic edifices emplaced within subglacial cavities. The cavity size reflects the competing effects of enlargement by melting and closure by downward ductile deformation of the ice roof, which occurs when the cavity pressure is less than glaciostatic due to meltwater drainage. Eruptions of basaltic magma from fissures and point sources are considered, which form either hemicylindrical or hemispherical cavities. The rate of roof closure can therefore be estimated using Nye's law. The cavity size, edifice size, and depth of meltwater above the edifice are predicted by the model and are used to identify two potential eruption mechanisms: explosive and intrusive. When the cavity is considerably larger than the edifice, hydroclastic fragmentation is possible via explosive eruptions, with deposition of tephra by eruption‐fed aqueous density currents. When the edifice completely fills the cavity, rising magma is likely to quench within waterlogged tephra in a predominantly intrusive manner. The models were run for a range of magma discharge rates, ice thicknesses and cavity pressures relevant to subglacial volcanism in Iceland. Explosive eruptions occur at high magma discharge rates, when there is insufficient time for significant roof closure. The models correctly predict the style of historic and Pleistocene subglacial fissure eruptions in Iceland and are used to explain the contrasting sedimentology of basaltic and rhyolitic tuyas. The models also point to new ways of unraveling the complex coupling between eruption mechanisms and glacier response during subglacial eruptions.
Multivariate reconstruction of missing data in sea surface temperature, chlorophyll, and wind satellite fields
Authors: Alvera‐Azcárate A. , Barth A. , Beckers J.‐M. , Weisberg R. H.
Published: March 2007

An empirical orthogonal function–based technique called Data Interpolating Empirical Orthogonal Functions (DINEOF) is used in a multivariate approach to reconstruct missing data. Sea surface temperature (SST), chlorophyll a concentration, and QuikSCAT winds are used to assess the benefit of a multivariate reconstruction. In particular, the combination of SST plus chlorophyll, SST plus lagged SST plus chlorophyll, and SST plus lagged winds have been studied. To assess the quality of the reconstructions, the reconstructed SST and winds have been compared to in situ data. The combination of SST plus chlorophyll, as well as SST plus lagged SST plus chlorophyll, significantly improves the results obtained by the reconstruction of SST alone. All the experiments correctly represent the SST, and an upwelling/downwelling event in the West Florida Shelf reproduced by the reconstructed data is studied.
Effect of vertical mixing on the Atlantic Water layer circulation in the Arctic Ocean
Authors: Zhang Jinlun , Steele Mike
Published: March 2007

An ice‐ocean model has been used to investigate the effect of vertical mixing on the circulation of the Atlantic Water layer (AL) in the Arctic Ocean. The motivation of this study comes from the disparate AL circulations in the various models that comprise the Arctic Ocean Model Intercomparison Project (AOMIP). It is found that varying vertical mixing significantly changes the ocean's stratification by altering the vertical distribution of salinity and hence the structure of the arctic halocline. In the Eurasian Basin, the changes in ocean stratification tend to change the strength and depth of the cyclonic AL circulation, but not the basic circulation pattern. In the Canada Basin, however, the changes in ocean stratification are sufficient to alter the direction of the AL circulation. Excessively strong vertical mixing drastically weakens the ocean stratification, leading to an anticyclonic circulation at all depths, including both the AL and the upper layer that consists of the surface mixed layer and the halocline. Overly weak vertical mixing makes the ocean unrealistically stratified, with a fresher and thinner upper layer than observations. This leads to an overly strong anticyclonic circulation in the upper layer and an overly shallow depth at which the underlying cyclonic circulation occurs. By allowing intermediate vertical mixing, the model does not significantly drift away from reality and is in a rather good agreement with observations of the vertical distribution of salinity throughout the Arctic Ocean. This realistic ocean stratification leads to a realistic cyclonic AL circulation in the Canada Basin. In order for arctic ice‐ocean models to obtain realistic cyclonic AL circulation in the Canada Basin, it is essential to generate an upward concave‐shaped halocline across the basin at certain depths, consistent with observations.
Variation of soluble and insoluble calcium in red rains related to dust sources and transport patterns from North Africa to northeastern Spain
Authors: Avila A. , Alarcón M. , Castillo S. , Escudero M. , García Orellana J. , Masqué P. , Querol X.
Published: March 2007

We use the chemical composition of African dust delivered by red rains at a rural site in northeastern Spain (Montseny, 41°46′N, 2°21′E) to describe its relationship with the possible provenance areas and the processes occurring during transport. To this end, we obtained the red rain insoluble composition for the major elements (Al, Fe, Ca, Mg, K, P, Ti, and Na) in 30 filters, the 210Pb concentration in 23 filters, and the soluble cation concentrations (Na, K, Ca, and Mg) in 28 coincident red rain samples. These samples comprised most major events occurring at the site from 1983 to 2002. On the basis of back trajectories and satellite images, a distinction has been made between an eastern and western air mass flux with respect to 0° Greenwich for the analyzed samples. Principal component and ANOVA analyses between the two provenance groups have shown striking differences in the insoluble phase, with eastern samples being significantly richer in insoluble Ca, Mg, and Sr compared to western samples. Conversely, western samples had significantly higher concentrations of insoluble Al, Fe, K, V, and 210Pb than eastern samples. Therefore, in the insoluble phase, the ratios of various elements to Ca were significantly higher in western provenances. However, these differences disappeared when considering bulk Ca ratios (bulk Ca = insoluble + soluble Ca). Neither of the ratios Fe/Al and Ti/Fe showed significant differences. This lack of differences is interpreted in view of a similar carbonated lithology broadly underlying both areas. The difference in insoluble Ca with respect to total Ca between provenances (Cainsoluble/Catotal = 0.10 and 0.70 for western and eastern trajectories, respectively) is interpreted as a difference in calcite dissolution during transport. Evidence from 210Pb data and from the length of the back trajectories indicates that western trajectories covered a longer distance than the eastern ones; their higher soluble Ca could be due to (1) higher calcite dissolution due to longer contact with wet fronts from the Atlantic and (2) particle segregation during transport, with finer (carbonate) particles more prone to dissolution due to a higher surface to volume ratio.
Comparison of CHAMP and Digisonde plasma frequencies at Jicamarca, Peru
Authors: McNamara L. F. , Cooke D. L. , Valladares C. E. , Reinisch B. W.
Published: March 2007

Ionospheric plasma frequencies at the altitude of the CHAMP satellite have been deduced from ionosonde true‐height profiles for Jicamarca, Peru, and have been compared with the in situ measurements made by CHAMP. The differences between the plasma frequencies have been found to be well within the uncertainties associated with the ionosonde profiles, confirming the validity of the CHAMP measurements. For satellite‐ionosonde separations of less than 250 km and for satellite altitudes below the peak of the F2 layer, the average discrepancy between the two plasma frequencies is 0.25 MHz or 4%. For the most reliable ionosonde measurements, the average discrepancies reduce to 0.18 MHz (or 1.7%), with a standard deviation of 0.16 MHz (or 1.5%). Given the validity of the CHAMP plasma frequencies, corresponding ionosonde and CHAMP observations have been used to support the practice of extending the ionosonde profile above hmF2 by assuming a Chapman layer with a constant scale height equal to that of the lower side of the F2 layer peak. The average discrepancy for CHAMP passing above the peak of the F2 layer is 0.22 MHz (or 2.6%), and the standard deviation is 0.8 MHz (or 13.3%).
Form and stability of step‐pool channels: Research progress
Authors: Church Michael , Zimmermann André
Published: March 2007

Research examining the hydraulics, morphology, and stability of step‐pool mountain streams has blossomed in the last decade, resulting in more than a dozen dissertations. These, along with other research projects, have transformed our understanding of step‐pool channels. Contributions have been made toward understanding depositional step formation and destruction, scour downstream of steps, step‐pool hydraulics, and the effect of sediment transport on step stability. We propose that depositional steps exist in a jammed state whereby the boulders are structurally arranged within the channel and thereby stabilize it. Once a step has formed, a scour pool with a characteristic length and depth develops downstream, creating a zone where additional steps are unlikely to occur. Downstream of the scour hole, steps are more likely to occur as the high energy associated with the plunge pool has dissipated. Data suggest that the presence of cobbles or boulders limits pool scour as well as the degree to which well‐defined, channel‐spanning step‐pools form. We propose a state‐space for step‐pools in which conditions for a step to form include (1) the ratio between width and boulder diameter (the jamming ratio), (2) the ratio between applied shear stress and the stress needed to mobilize the bed (relative Shields number), and (3) the ratio between bed material supply and discharge (bed sediment concentration). Available data suggest this model is plausible. Emerging critical research questions are discussed.
Estimating shear stress from moving boat acoustic Doppler velocity measurements in a large gravel bed river
Authors: Sime Louise C. , Ferguson Robert I. , Church Michael
Published: March 2007

Moving boat acoustic Doppler current profiling (ADCP) is increasingly used to measure discharge in large rivers. We investigate whether useful information about bed shear stress can be recovered from such data. Alternative ways to estimate local bed shear stress using the logarithmic law of the wall and spatial averaging are tested using ADCP transects across lower Fraser River, Canada. Repeatability is assessed by comparing estimates from outward and return boat tracks. The most precise method uses the vertically averaged mean velocity and a zero‐velocity height based on bed grain size information. The accuracy of the assumed zero‐velocity height can be judged by consistency between estimates using mean velocity and near‐bed velocity. Shear stress estimates from unconstrained log‐law fits are less repeatable and tend to overpredict, and mean shear stress estimates using the depth‐slope product are unreliable in this river because of nonuniform flow.
Stable isotope ratios of tap water in the contiguous United States
Authors: Bowen Gabriel J. , Ehleringer James R. , Chesson Lesley A. , Stange Erik , Cerling Thure E.
Published: March 2007

Understanding links between water consumers and climatological (precipitation) sources is essential for developing strategies to ensure the long‐term sustainability of water supplies. In pursing this understanding a need exists for tools to study and monitor complex human‐hydrological systems that involve high levels of spatial connectivity and supply problems that are regional, rather than local, in nature. Here we report the first national‐level survey of stable isotope ratios in tap water, including spatially and temporally explicit samples from a large number of cities and towns across the contiguous United States. We show that intra‐annual ranges of tap water isotope ratios are relatively small (e.g., <10‰ for δ2H) at most sites. In contrast, spatial variation in tap water isotope ratios is very large, spanning ranges of 163‰ for δ2H and 23.6‰ for δ18O. The spatial distribution of tap water isotope ratios at the national level is similar to that of stable isotope ratios of precipitation. At the regional level, however, pervasive differences between tap water and precipitation isotope ratios can be attributed to hydrological factors in the water source to consumer chain. These patterns highlight the potential for monitoring of tap water isotope ratios to contribute to the study of regional water supply stability and provide warning signals for impending water resource changes. We present the first published maps of predicted tap water isotope ratios for the contiguous United States, which will be useful in guiding future research on human‐hydrological systems and as a tool for applied forensics and traceability studies.
Probabilistic risk analysis in subsurface hydrology
Authors: Tartakovsky Daniel M.
Published: March 2007

We present a general framework for probabilistic risk assessment (PRA) of subsurface contamination. PRA provides a natural venue for the rigorous quantification of structural (model) and parametric uncertainties inherent in predictions of subsurface flow and transport. A typical PRA starts by identifying relevant components of a subsurface system (e.g., a buried solid‐waste tank, an aquitard, a remediation effort) and proceeds by using uncertainty quantification techniques to estimate the probabilities of their failure. These probabilities are then combined by means of fault‐tree analyses to yield probabilistic estimates of the risk of system failure (e.g., aquifer contamination). Since PRA relies on subjective probabilities, it is ideally suited for assimilation of expert judgment and causal relationships.
An Investigation of Personality Traits in Relation to Job and Career Satisfaction of Information Technology Professionals
Authors: Lounsbury John W. , Moffitt Lauren , Gibson Lucy W. , Drost Adam W. , Stevens Mark
Published: March 2007

Personality traits were examined in relation to job satisfaction and career satisfaction for 1059 information technology (IT) professionals. As hypothesized, eight traits were significantly related to both job and career satisfaction: Assertiveness, Emotional Resilience, Extraversion, Openness, Teamwork Disposition, Customer Service Orientation, Optimism, and Work Drive. Regression analyses indicated that sets of three and four traits accounted for 17 and 25%, respectively, of job and career satisfaction variance. As expected, career satisfaction correlations were of generally higher magnitude than corresponding job satisfaction correlations. Results were interpreted in terms of IT research and theorizing. The findings that Extraversion and Teamwork Disposition were related to job and career satisfaction contravenes job descriptions and career planning advice, suggesting that independent introverts are better suited for IT work. Given that adult personality is antecedent to work experiences, it was suggested that future research proposing to show the effects of work-related factors such as pay and challenge on job or career satisfaction should first control for personality traits. Other practical and theoretical implications were noted.
Pore size distributions in polyelectrolyte multilayers determined by nuclear magnetic resonance cryoporometry
Authors: Vaca Chávez Fabián , Schönhoff Monika
Published: March 2007

Polyelectrolyte multilayers (PEMs) are thin films, which are assembled one molecular layer at a time, by alternatingly adsorbing polycations and polyanions making use of their attractive electrostatic interaction. Since the porosity of PEMs is one of the properties of major interest, in the current work the first pore size distribution of PEMs in samples consisting of silica particles coated with poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) is presented. To this end, the nuclear magnetic resonance (NMR) cryoporometry technique was applied. The proton NMR signal of liquid water is analyzed assuming a log normal distribution of motional correlation times. From the results, it is possible to determine the size of water sites in the layers to around 1nm. In addition, a slight variation with the number of layers is found. The average pore size agrees with cutoff sizes found in permeation experiments.
The Thatcher Illusion: Rotating the Viewer Instead of the Picture
Authors: Lobmaier Janek S , Mast Fred W
Published: March 2007

Faces are difficult to recognise when presented upside down. This effect of face inversion was effectively demonstrated with the ‘Thatcher illusion’ by Thompson (1980 Perception9 483–484). It has been tacitly assumed that this effect is due to inversion relative to retinal coordinates. Here we tested whether it is due to egocentric (ie retinal) inversion or whether the orientation of the body with respect to gravity also influences the face-inversion effect. A 3-D human turntable was used to test subjects in 5 different body-tilt (roll) orientations: 0°, 45°, 90°, 135°, and 180°. The stimuli consisted of 4 ‘normal’ and 4 ‘thatcherised’ faces and were presented in 8 different orientations in the picture plane. The subjects had to decide in a yes – no task whether the faces were ‘normal’ or ‘thatcherised’. Analysis of the d' values revealed a significant effect of stimulus orientation and body tilt. The significant effect of body tilt was due to a drop in d' values in the 135° orientation. This result is compared to findings of studies on the subjective visual vertical, where larger errors occurred in body-tilt orientations between 90° and 180°. The present findings suggest that the face-inversion effect relies mainly on retinal coordinates, but that in head-down body-tilt orientations around 135° the gravitational reference frame has a major influence on the perception of faces.