bluuebunny/crossref_metadata_2025 huggingface dataset:
PALS free volume and mechanical properties in dimethacrylate‐based thermosets
Authors: Rey Laurent , Galy Jocelyne , Sautereau Henry , Simon George P , Cook Wayne D
Published: April 2004

Dynamic mechanical thermal analysis, impact strength, bulk density and double‐bond conversion are reported for a series of dimethacrylate‐based networks in which the addition of styrene or/and divinylbenzene co‐monomer leads to variations in the morphology and crosslink density. The glass transition region was very broad for DVB‐rich networks and this was interpreted in terms of network heterogeneity. The mean size and the size distribution of free‐volume holes were estimated via analyses of positron annihilation lifetime spectroscopy (PALS) measurements at 22 °C and were found to be inversely correlated with the bulk density and dependent on the network heterogeneity. The PALS free volume was raised for DVB‐rich systems, due to the poor molecular packing in these highly crosslinked systems and because some regions in this heterogeneous network were in a rubbery state. The impact strength was found to be lower for the more highly crosslinked systems but was inversely correlated with the level of molecular mobility as measured by DMTA. Copyright © 2004 Society of Chemical Industry
Control of the morphology of waterborne nanocomposite films
Authors: Grillet Anne‐Cécile , Brunel Sylvain , Chevalier Yves , Usoni Sandra , Ansanay‐Alex Valérie , Allemand Jacques
Published: April 2004

Nanocomposite materials are prepared by drying a mixed colloidal suspension of film‐forming latex and silica. The dispersion state of the silica particles in the dry film controls the properties. We describe, with the help of some examples, how the colloidal stability of the particles in the mixed suspension dictates the final morphology of the dry film. Next, some recent work aimed at controlling the morphology by means of formulation additives is described. Such additives are either surfactants or polymer dispersants (block copolymers) which stabilize the particles (latex and/or silica) in the drying suspension. As a result of the mixing‐and‐drying preparation process, suitable additives are necessarily different from the conventional dispersants used in the formulation of composites prepared by means of melt‐processing. Copyright © 2004 Society of Chemical Industry
A new route for the preparation of cyano‐containing poly(N‐isopropylacrylamide) microgel latex for specific immobilization of antibodies
Authors: Zhou Guangchang , Veron Laurent , Elaissari Abdelhamid , Delair Thierry , Pichot Christian
Published: April 2004

A prepolymerization process was used to prepare functionalized poly(N‐isopropylacrylamide) latexes with surface cyano groups. The functionalized latexes prepared were characterized by FTIR, 1H NMR, scanning electron microscopy and quasi‐elastic light scattering. In addition, the polymerization conversion and the water‐soluble polymer amounts were quantified. The polymerization conversions were found to be above 80% with 5–14 wt% of water soluble polymer formation. The immobilization of antibody (immunoglobulin) onto such cyano‐containing thermally sensitive particles, suggests the feasibility of specific dipole–dipole interactions between the cyano and hydroxyl functional groups from particle and antibody, respectively. Copyright © 2004 Society of Chemical Industry
Trends in the bonding of the first‐row transition metal compounds: V(001) surface, TM‐oxide and nitride molecules, and AunTi (2≤n≤7) clusters
Authors: Fernández E. M. , Torres M. B. , Balbás L. C.
Published: April 2004

We have performed a systematic study of the electronic and geometrical structure of several compounds containing first‐row transition metal by means of first principles spin‐density functional calculations based on norm‐conserving pseudo‐potentials and numerical basis sets of the double ζ plus polarization type. To achieve a realistic description of these compounds, we find that the pseudo‐potentials for 3d elements with d‐orbital occupation up to 5 electrons must contain at least the semi‐core state 3p in the valence shell. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
The effects of school, family, self‐concept, and deviant behaviour on adolescent suicide ideation
Authors: Dukes Richard L. , Lorch Barbara (Day)
Published: April 2004

In this study of a population of junior and senior high school students in a mid‐sized, Western city, adolescent emotional and ideological disparity with parents and disparity between the importance the adolescent placed on academic achievement and satisfaction with academic achievement were linked to suicide ideation through the intervening variables of self‐esteem, purpose in life, and two forms of deviant behaviour — alcohol use and eating disorder. Self‐confidence and the deviant behaviours of delinquency and drug use did not prove to be meaningful intervening variables.
Adolescent decision‐making: the development of competence
Authors: Mann Leon , Harmoni Ros , Power Colin
Published: April 2004

This article reviews evidence relating to the development of competence in decision‐making during adolescence. The review focuses on cognitive aspects of decision‐making and discusses nine indicators of competence: choice; comprehension; creativity; compromise; consequentiality; correctness; credibility; consistency; and commitment. The evidence suggests that by the age of 15 years many adolescents show a reliable level of competence in metacognitive understanding of decision‐making, creative problem‐solving, correctness of choice, and commitment to a course of action. Young adolescents (12–14 years) are less able to create options, identify a wide range of risks and benefits, foresee the consequences of alternatives, and gauge the credibility of information from sources with vested interests. No evidence is available relating to age differences in willingness to make choices, devise compromises, and show consistency of choices. Barriers to achieving competence in decision‐making during adolescence include attitudinal constraints (e.g. beliefs about the proper age for making decisions), peer group pressures to conformity, breakdowns in family structure and functioning, and restricted legal rights to make important personal decisions (e.g. to donate blood or body tissue).
A disorder unique to adolescence? The Kleine‐Levin syndrome
Authors: Cawthron Paul
Published: April 2004

The Kleine‐Levin syndrome is a rare disorder. In the pure form it is a diagnosis that can only be made in adolescent males. The patient described fits this category and can be added to similar case histories reported in the world literature. Evidence is presented to suggest a link between the Kleine‐Levin syndrome and the cyclical affective disorders.
Self‐esteem in girls aged 11–12: baseline findings from a planned prospective study of vulnerability to eating disorders
Authors: Button Eric
Published: April 2004

The paper reports on the first stage of a planned prospective study of self‐esteem and risk for eating disorders in 594 schoolgirls aged 11–12. Subjects completed a short questionnaire which incorporated the Rosenberg Self‐Esteem Scale and a few “problem” questions, including one on fatness concern. Low self‐esteem was associated with increased fatness concern, but also with problems in general. The girls will be followed up in detail at age 15–16, with a view to clarifying whether low self‐esteem is predictive of clinically significant eating disorders.
Decision‐making competence and self‐esteem: a comparison of parents and adolescents
Authors: Brown Jacob E. , Mann Leon
Published: April 2004

This study examined the relationship between parents' and adolescents' confidence and competence in making decisions. Data were obtained from a survey sample of 584 adolescents, aged 12–18 years living in Adelaide, South Australia. Data were obtained from a sample of 352 parents of the adolescents by means of a mail survey. Parents' decision‐making self‐esteem was related to the self‐esteem of young adolescents. The relationship was stronger for males than females. There was a relationship between mothers' decision‐making competence and the competence of young female adolescents. Thus, partial support was provided for modelling theory in regard to the role of parents in the socialization of decision‐making skills and confidence.
An existentialist account of identity formation
Authors: Bilsker Dan
Published: April 2004

An account of James Marcia's identity formation model is given in the language of existentialist philosophy. Parallels between ego‐identity and existentialist approaches are examined and identity is described in terms of existentialist concepts formulated by Martin Heidegger (Being and Time) and Jean‐Paul Sartre (Being and Nothingness). While identity formation has previously been formulated in terms of ego‐analytic theory, this paper argues and seeks to demonstrate that significant benefits accrue from an existentialist account. These benefits include clarification of difficult theoretical issues, delineation of specific research directions and enrichment of clinical understanding.
Simulated Navigation Performance with Marine Electronic Chart and Information Display Systems (ECDIS)
Authors: Donderi Don C. , Mercer Robert , Blair Hong M. , Skinner Douglas
Published: April 2004

Licensed mariners carried out two simulated navigation studies testing electronic chart and information display systems (ECDIS) against paper chart navigation. In the first study, six mariners each completed approaches to Halifax, Nova Scotia, harbour with good and bad visibility and a range of wind and currents. Conditions included chart with radar, ECDIS with radar overlay and ECDIS with separate radar. ECDIS produced better performance and a smaller workload than paper charts and the radar overlay was slightly better than the separate radar display. In the second study, six new mariners completed exercises with low visibility and heavy or light radar traffic using ECDIS with radar overlay, ECDIS without overlay and ECDIS with optional overlay. Mariners preferred the optional overlay but all three conditions produced about equal performance. Based on mariners' performance and expressed preference, we recommend that ECDIS systems provide optional radar overlays.
Developing a cultural syllabus for business language e-learning materials
Authors: ROGERSON-REVELL PAMELA
Published: April 2004

The increasing emphasis on ‘e-learning’ in all sectors of education, including
vocational and professional domains, offers great potential to provide interactive, up-dateable multimedia materials
which allow greater flexibility of access and use. This paper reports on an EU-funded, e-learning project which aims to
exploit on-line technology to develop intercultural business and language skills for European managers in the construction
industy. It advocates an integrated approach to language and culture training, describing how a ‘cultural syllabus’
was designed to develop users’ understanding of key aspects of European work culture and practices alongside their
professional language skills. The resulting matrix syllabus incorporates insights from theoretical frameworks together
with factual information and authentic accounts of cross cultural work experiences. It argues that the growing demand for
on-line learning materials needs to be matched by great attention to quality of course and materials design so that
technology enhances, rather than detracts from, content and pedagogy.
Preparing language exams: an online learning system with dictionary and email tandem
Authors: WEBER VANESSA , ABEL ANDREA
Published: April 2004

We present an on-line learning system for the Italian and German languages especially created to help the people
living in the Autonomous Province of Bolzano/Bozen prepare the so-called bilingual proficiency exam. In the first part of the paper we
present the peculiar political, social and linguistic situation of the Province and describe the bilingual proficiency exam. After having
clarified the background in which our learning system originates, we will concentrate on the system itself presenting the different parts
it consists of. Section 4 will describe the system function, and section 5 will make some final comments and highlight future
prospects.
Duality in Quantum Information Geometry
Authors: Streater R. F.
Published: April 2004

Let [Formula: see text] be a separable Hilbert space. We consider the manifold [Formula: see text] consisting of density operators ρ on [Formula: see text] such that ρp is of trace class for some p ɛ (0, 1). We say [Formula: see text] is nearby ρ if there exists C > 1 such that C−1 ρ < σ < Cρ. We show that the space of nearby points to ρ can be furnished with the two flat connections known as the (±)-affine structures, which are dual relative to the BKM metric. We furnish [Formula: see text] with a norm making it into a Banach manifold.
Rapid helium isotopic variability in Mauna Kea shield lavas from the Hawaiian Scientific Drilling Project
Authors: Kurz Mark D. , Curtice Joshua , Lott Dempsey E. , Solow Andy
Published: April 2004

This paper presents new magmatic helium isotopic compositions in a suite of lavas from phase II of the Hawaiian Scientific Drilling Project (HSDP2) core, which sampled Mauna Kea volcano to a maximum depth of 3098 m below sea level. Most of the measurements were performed by in vacuo crushing of olivine phenocrysts, but include submarine pillow glasses from the 2200 to 2500 meter depth interval, and orthopyroxene phenocrysts from an intrusive at 1880 m. The magmatic 3He/4He ratios range from 6 to 24.7 times atmospheric (Ra), which significantly extends the range of values for Mauna Kea volcano. The 3He/4He ratios are lowest (i.e., close to MORB values of ∼8 Ra) near the top of the Mauna Kea section and rise slowly, to 10–12 Ra, at 1000 m below sea level, consistent with results from the HSDP1 core. At depths greater than 1000 m in the core, primarily in the submarine lavas, there are brief periods when the 3He/4He ratios are higher than 14.5 Ra, always returning to a baseline value. Twelve such excursions were identified in the core; all but one are in the submarine section, and most (7) are in the deepest section, at depths of 1950 to 3070 m. The baseline 3He/4He value rises from 10–12 Ra near 1000 m depth to 12–14 Ra at 3000 m. The helium spikes are found only in lavas that are older than 380 Ka in age, based on an age model derived from Ar‐Ar data (W. D. Sharp et al., manuscript in preparation, 2003). Excluding the excursions defined by single lava flows (3) and intrusive units (3), the average spike duration is approximately 15 (±9) Ka (n = 6). The high 3He/4He spikes are interpreted as pulses of magma from the center of the actively upwelling Hawaiian hot spot. The short duration of the high 3He/4He excursions suggests that Mauna Kea was never directly over high the 3He/4He component of the plume (during the HSDP2 eruptive period), presumed to be the plume center. Assuming that the Mauna Kea helium spikes result from melting of heterogeneities within the plume, their short duration implies that the length scales of heterogeneities in the solid upwelling mantle are between 60 m and 12 km (for upwelling rates of 2 to 40 cm/yr). The high 3He/4He are associated with high 208Pb/204Pb, and relatively low 143Nd/144Nd, Zr/Nb, and SiO2. The correlations with major elements, trace elements and isotopes demonstrate that helium is coupled to the other geochemical variations, and that the Mauna Kea isotopic variability is caused by heterogeneities within the upwelling plume.
On the modeling of sand wave migration
Authors: Besio Giovanni , Blondeaux Paolo , Brocchini Maurizio , Vittori Giovanna
Published: April 2004

We describe a simple mathematical model capable of reproducing the main features of sand wave inception and growth. In particular we focus on the prediction of the migration rates that sand waves undergo because of tidal and residual currents. The model adequately predicts migration rates even for the cases of upstream‐propagating sand waves, i.e., for sand waves which migrate in the direction opposite to that of the residual current. We show that upstream/downstream propagation is mainly controlled by the relative strength of the residual current with respect to the amplitude of the quarter‐diurnal tide constituent and by the phase shift between the semi‐diurnal and quarter‐diurnal tide constituents. Therefore, to accurately predict field cases, a detailed knowledge of the direction, strength, and phase of the different tide constituents is required.
Interlaboratory comparison study of Mg/Ca and Sr/Ca measurements in planktonic foraminifera for paleoceanographic research
Authors: Rosenthal Yair , Perron‐Cashman Suzanne , Lear Caroline H. , Bard Edouard , Barker Stephen , Billups Katharina , Bryan Martha , Delaney Margaret L. , deMenocal Peter B. , Dwyer Gary S. , Elderfield Henry , German Chris R. , Greaves Mervyn , Lea David W. , Marchitto Thomas M. , Pak Dorothy K. , Paradis Georges L. , Russell Ann D. , Schneider Ralph R. , Scheiderich Kathleen , Stott Lowell , Tachikawa Kazuyo , Tappa Eric , Thunell Robert , Wara Michael , Weldeab Syee , Wilson Paul A.
Published: April 2004

Thirteen laboratories from the USA and Europe participated in an intercomparison study of Mg/Ca and Sr/Ca measurements in foraminifera. The study included five planktonic species from surface sediments from different geographical regions and water depths. Each of the laboratories followed their own cleaning and analytical procedures and had no specific information about the samples. Analysis of solutions of known Mg/Ca and Sr/Ca ratios showed that the intralaboratory instrumental precision is better than 0.5% for both Mg/Ca and Sr/Ca measurements, regardless whether ICP‐OES or ICP‐MS is used. The interlaboratory precision on the analysis of standard solutions was about 1.5% and 0.9% for Mg/Ca and Sr/Ca measurements, respectively. These are equivalent to Mg/Ca‐based temperature repeatability and reproducibility on the analysis of solutions of ±0.2°C and ±0.5°C, respectively. The analysis of foraminifera suggests an interlaboratory variance of about ±8% (%RSD) for Mg/Ca measurements, which translates to reproducibility of about ±2–3°C. The relatively large range in the reproducibility of foraminiferal analysis is primarily due to relatively poor intralaboratory repeatability (about ±1–2°C) and a bias (about 1°C) due to the application of different cleaning methods by different laboratories. Improving the consistency of cleaning methods among laboratories will, therefore, likely lead to better reproducibility. Even more importantly, the results of this study highlight the need for standards calibration among laboratories as a first step toward improving interlaboratory compatibility.
Prevalence of the Antarctic Circumpolar Wave over the last two millenia recorded in Dronning Maud Land ice
Authors: Fischer H. , Traufetter F. , Oerter H. , Weller R. , Miller H.
Published: April 2004

The influence of atmospheric circulation patterns on sea salt aerosol deposition in the study area of the new EPICA (European Project for Ice Coring in Antarctica) deep drilling in Dronning Maud Land (DML), Antarctica, has been investigated. Comparison of ice core records with reanalysis data showed that recent sea salt concentrations are strongly influenced by the occurrence of a blocking high pressure ridge over the eastern and enhanced storm activity over the western Atlantic sector of the Southern Ocean (SO) leading to marine intrusions, thus enhanced sea salt export, into DML. These variations occur with periods of 4–5 and 12–14 yr, the prior being associated with the Antarctic Circumpolar Wave (ACW). The prevalence of these periodicities in a 2000 year ice core record from DML shows for the first time that the ACW is a prevalent feature of SO atmosphere dynamics over the last two millennia.
Linking pressure and saturation through interfacial areas in porous media
Authors: Cheng J.‐T. , Pyrak‐Nolte Laura J. , Nolte David D. , Giordano Nicholas J.
Published: April 2004

Using transparent microfluidic cells to study the two‐phase properties of a synthetic porous medium, we establish that the interfacial area per volume between nonwetting and wetting fluids lifts the ambiguity associated with the hysteretic relationship between capillary pressure and saturation in porous media. The interface between the nonwetting and wetting phases is composed of two subsets: one with a unique curvature determined by the capillary pressure, and the other with a distribution of curvatures dominated by disjoining pressure. This work provides experimental support for recent theoretical predictions that the capillary‐dominated subset plays a role analogous to a state variable. Any comprehensive description of multiphase flow properties must include this interfacial area with the traditional variables of pressure and fluid saturation.
Conductivity dependence of cross‐polar potential saturation
Authors: Nagatsuma T.
Published: April 2004

The cross‐polar potential tends to be saturated when the value of the merging electric field (Em) is high. Using data from the Wind and ACE satellites and the northern polar cap index (PCN) as a proxy for the cross‐polar potential, Nagatsuma [2002] has shown that the degree of saturation does not depend on the intensity of the interplanetary magnetic field on the GSM‐YZ plane (BT) but depends on that of Em. This result supports the idea that the enhancement of the region 1 current plays a significant role in regulating the efficiency of the solar wind‐magnetosphere interaction, since the intensity of the region 1 current is a function of Em. If the region 1 current controls the efficiency of the interaction, ionospheric conductivity also controls the degree of saturation, since the region 1 current system is a voltage generator. We have examined the solar zenith angle (SZA) dependence of the PCN saturation and have compared the SZA dependences of ionospheric conductivity models. Our statistical results show that the degree of saturation increases with decreasing solar zenith angle at the northern corrected geomagnetic pole under sunlit conditions and that the opposite trend occurs during darkness. These characteristics are explained by the SZA dependence of the total Pedersen conductivity estimated from the northern and southern polar caps. This result confirms that the development of the region 1 current plays a significant role in regulating magnetospheric convection.
Stress triggering and earthquake probability estimates
Authors: Hardebeck Jeanne L.
Published: April 2004

Stress triggering and fault interaction concepts are beginning to be incorporated into quantitative earthquake probability estimates. However, the current methods are limited in their range of compatible earthquake nucleation models. I introduce a new general method for translating stress changes into earthquake probability changes, which can potentially be used with any physical fault model. Given the large uncertainties in earthquake probability calculations, it is unclear whether the small probability changes resulting from stress transfer are significant and meaningful for the purposes of seismic hazard assessment. I present a case study of the effect of the 1992 M7.3 Landers, California, earthquake on the probability of a major earthquake on the San Andreas Fault in southern California. This is a large event in a well‐studied region, which should maximize the probability change signal and minimize the uncertainty. Even for this scenario, the earthquake probability change for a 30 year period is not significant with respect to the initial uncertainty in the earthquake probability. This example, comparisons with other studies, and exploration of parameter space imply that the probability changes due to stress triggering are significant only for time intervals which are short compared to the repeat time of the target fault. Therefore stress change calculations will be useful in long‐term seismic hazard assessment only for low slip‐rate faults. Otherwise, stress triggering calculations are best utilized in the short‐term immediately following a major earthquake.
Effective stress law for the permeability of clay‐rich sandstones
Authors: Al‐Wardy Widad , Zimmerman Robert W.
Published: April 2004

Two models of clay‐rich sandstones are analyzed to explain the relative sensitivity of permeability to pore pressure and confining pressure. In one model the clay lines the entire pore wall in a layer of uniform thickness, and in the second model the clay is distributed in the form of particles that are only weakly coupled to the pore walls. Equations of elasticity and fluid flow are solved for both models, giving expressions for the effective stress coefficients in terms of clay content and the elastic moduli of the rock and clay. Both models predict that the permeability will be much more sensitive to changes in pore pressure than to changes in confining pressure. The clay particle model gives somewhat better agreement with data from the literature and with new data on a Stainton sandstone having a solid volume fraction of 8% clay.
Depth dependence of permeability in the Oregon Cascades inferred from hydrogeologic, thermal, seismic, and magmatic modeling constraints
Authors: Saar M. O. , Manga M.
Published: April 2004

We investigate the decrease in permeability, k, with depth, z, in the Oregon Cascades employing four different methods. Each method provides insight into the average permeability applicable to a different depth scale. Spring discharge models are used to infer shallow (z < 0.1 km) horizontal permeabilities. Coupled heat and groundwater flow simulations provide horizontal and vertical k for z < 1 km. Statistical investigations of the occurrences of earthquakes that are probably triggered by seasonal groundwater recharge yield vertical k for z < 5 km. Finally, considerations of magma intrusion rates and water devolatilization provide estimates of vertical k for z < 15 km. For depths >0.8 km, our results agree with the power law relationship, k = 10−14 m2 (z/1 km)−3.2, suggested by Manning and Ingebritsen [1999] for continental crust in general. However, for shallower depths (typically z ≤ 0.8 km and up to z ≤ 2) we propose an exponential relationship, k = 5 × 10−13 m2 exp (−z/0.25 km), that both fits data better (at least for the Cascades and seemingly for continental crust in general) and allows for a finite near‐surface permeability and no singularity at zero depth. In addition, the suggested functions yield a smooth transition at z = 0.8 km, where their permeabilities and their gradients are similar. Permeabilities inferred from the hydroseismicity model at Mount Hood are about one order of magnitude larger than expected from the above power law. However, higher permeabilities in this region may be consistent with advective heat transfer along active faults, causing observed hot springs. Our simulations suggest groundwater recharge rates of 0.5 ≤ uR ≤ 1 m/yr and a mean background heat flow of Hb ≈ 0.080–0.134 W/m2 for the investigated region.
Interannual variability and ventilation timescales in the ocean cavity beneath Filchner‐Ronne Ice Shelf, Antarctica
Authors: Nicholls K. W. , Østerhus S.
Published: April 2004

Multiyear time series of ocean current and temperatures from beneath Filchner‐Ronne Ice Shelf, Antarctica, demonstrate both seasonal and interannual variability. The seasonal signal is visible at all measurement sites, although it was swamped for a 2‐year period (1999–2001) when extraordinarily light sea‐ice cover in the southern Weddell Sea during the 1997–1998 Austral summer caused an anomalously large pulse of High Salinity Shelf Water to flush beneath the ice shelf. The pulse was observed twice at an instrumented site near the Berkner Island coast, once on its way to the Filchner Depression and once after the signal had propagated around the depression and returned to the site as an anomalously large pulse of Ice Shelf Water. The timings of the signal allow an estimate of 24–30 months for the flushing timescales of the sub‐ice shelf ocean cavity, indicating that the cavity is highly responsive to external forcing. A timescale for the full ventilation of the cavity of 4–5 years is obtained from the length of time the sub‐ice shelf conditions take to return to their original state, a timescale significantly shorter than previous estimates.
Atmospheric ion‐induced nucleation of sulfuric acid and water
Authors: Lovejoy E. R. , Curtius J. , Froyd K. D.
Published: April 2004

Field studies show that gas phase nucleation is an important source of new particles in the Earth's atmosphere. However, the mechanism of new particle formation is not known. The predictions of current atmospheric nucleation models are highly uncertain because the models are based on estimates for the thermodynamics of cluster growth. We have measured the thermodynamics for the growth and evaporation of small cluster ions containing H2SO4 and H2O, and incorporated these data into a kinetic aerosol model to yield quantitative predictions of the rate of ion‐induced nucleation for atmospheric conditions. The model predicts that the binary negative ion H2SO4/H2O mechanism is an efficient source of new particles in the middle and upper troposphere. The ion‐induced HSO4−/H2SO4/H2O mechanism does explain nucleation events observed in the remote middle troposphere, but does not generally predict the nucleation events observed in the boundary layer.
Rapid sediment deposition and fine‐scale strata formation in the Hudson estuary
Authors: Traykovski Peter , Geyer Rocky , Sommerfield Chris
Published: April 2004

A 9 month time series of tripod‐mounted optical and acoustic measurements of sediment concentration and bed elevation was used to examine depositional processes in relationship to hydrodynamic variables in the Hudson River estuary. A series of cores was also taken directly under and adjacent to the acoustic measurements to examine the relation between the depositional processes and the resulting fine‐scale stratigraphy. The measurements reveal that deposition occurs as a result of sediment flux convergence behind a salinity front and that the accumulation rates are sufficient to deposit up to 25 cm of new high‐porosity sediment in a single ebb‐tidal phase. Subsequent dewatering and erosion reduces the thickness of the initial deposit to several centimeters. These depositional events were only observed on spring tides. Ten depositional events during two spring tidal cycles produced a seasonal deposit of 18 cm, consistent with estimates of seasonal deposition from cores. A proxy for near‐bed suspended grain size variations was estimated from the combined acoustic and optical measurements, implying that the erosional processes resuspend only the finer‐grained sediments, thus leaving behind silt and very fine grained sand beds. The thickness of the deposited homogenous clayey silt beds, and the vertical separation between beds interlaminated with silt and very fine sand, are roughly consistent with the acoustic measurements of changes in bed elevations during deposition and erosion. The variability in individual bed thickness is the result of variations of processes over an individual tidal cycle and is not a product of variations over the spring neap fortnightly timescale.
Use of dielectric spectroscopy to estimate ice content in frozen porous media
Authors: Bittelli Marco , Flury Markus , Roth Kurt
Published: April 2004

We investigate the use of dielectric spectroscopy to estimate ice content in frozen porous media. A dielectric mixing model was used to determine the volumetric fractions of the different phases, based on knowledge of the bulk and single‐phase dielectric permittivities. Measurement of the dielectric permittivities at two different frequencies with an impedance analyzer is required to infer ice content. One of the frequencies (25 kHz) has to be close to the relaxation frequency of ice; the other frequency (158 kHz or higher) must be well above the relaxation frequency of ice to obtain a different permittivity value of the ice phase. The theory was tested with three soil samples containing different amounts of clay. Dielectric permittivities of the soil samples were determined between 0.1 and 200 kHz, and in the temperature range of −30°C to +5°C. Ice content was successfully determined for a loamy sand sample. However, surface phenomena at low frequencies (such as double‐layer polarization, surface conduction, and Maxwell‐Wagner type effects) made ice content estimation using our proposed methods unfeasible in silty loam and clay samples, which had 13% and 46% clay by weight, respectively.
Irrigation‐induced changes in potential evapotranspiration in southeastern Turkey: Test and application of Bouchet's complementary hypothesis
Authors: Ozdogan Mutlu , Salvucci Guido D.
Published: April 2004

Since the early 1980s the southeastern part of Turkey has experienced major land use changes because of increasing irrigation. To determine the influence of large‐scale irrigation on surface hydrologic fluxes, we investigated feedback mechanisms between the land surface and atmosphere within the framework of Bouchet's complementary relationship between potential and actual evapotranspiration. Using 23 years of meteorological observations of temperature, humidity, wind speed, and radiation within the advection‐aridity model (which is built on the complementary theory), we found that potential evaporation has decreased over 50%, from about 14 mm d−1 to about 7 mm d−1, paralleling the increase in irrigated acreage over the same period. Pan evaporation data show a similar trend. The observed decline in potential evaporation is a direct result of decreases in wind speed and, to a lesser degree, increases in humidity. A comparison between reference values of evapotranspiration obtained from irrigation water use and evapotranspiration estimates from the advection‐aridity method show a reasonable correlation (root‐mean‐square error = 1.1 mm d−1), especially for large values of both variables. These results suggest that the rapid expansion of irrigation in southeastern Turkey has strongly modified the lower atmosphere in a way that appears consistent with Bouchet's complementary theory.
Impact of Management Accounting Information and AMT on Organizational Performance
Authors: Choe Jong-Min
Published: April 2004

This study empirically examined and identified specific types of management accounting information as well as conditions of learning facilitators for effective organizational learning under high levels of advanced manufacturing technology (AMT). In this study, the interaction and communication among functions as well as job rotation and experience were considered as the facilitators of organizational learning. This research investigated the relationship between the level of AMT and the amount of management accounting information (i.e. planning and control information and nonfinancial performance information). The empirical results showed that there is a significant positive relationship between the AMT level and the amount of information produced by management accounting information systems (MAISs). Significant positive correlations among the amount of information, degree of organizational learning, and production performance were also observed. Using structural equation modeling, this study examined causal relationships among AMT level, amount of information, learning facilitators, organizational learning, and production performance. The results of the study showed that under a high level of AMT, to give rise to a high degree of learning and, consequently, an increase of performance through the provision of information, facilitators of learning must be well-coordinated (i.e. highly utilized), and MAISs must produce a large amount of management accounting information (i.e. planning and control information and nonfinancial performance information).
Secreted proNGF is a pathophysiological death-inducing ligand after adult CNS injury
Authors: Harrington A. W. , Leiner B. , Blechschmitt C. , Arevalo J. C. , Lee R. , Mörl K. , Meyer M. , Hempstead B. L. , Yoon S. O. , Giehl K. M.
Published: April 2004

The unprocessed precursor of the neurotrophin nerve growth factor (NGF), proNGF, has been suggested to be a death-inducing ligand for the neurotrophin receptor p75. Whether proNGF is a true pathophysiological ligand that is secreted, binds p75, and activates cell death
in vivo
, however, has remained unknown. Here, we report that after brain injury, proNGF was induced and secreted in an active form capable of triggering apoptosis in culture. We further demonstrate that proNGF binds p75
in vivo
and that disruption of this binding results in complete rescue of injured adult corticospinal neurons. These data together suggest that proNGF binding to p75 is responsible for the death of adult corticospinal neurons after lesion, and they help to establish proNGF as the pathophysiological ligand that activates the cell-death program by means of p75 after brain injury. Interference in the binding of proNGF to p75 may provide a therapeutic approach for the treatment of disorders involving neuronal loss.
Activation of human medial prefrontal cortex during autonomic responses to hypoglycemia
Authors: Teves Denise , Videen Tom O. , Cryer Philip E. , Powers William J.
Published: April 2004

Studies in humans implicate the medial prefrontal cortex (MPFC) in complex cognitive and emotional states. We measured regional cerebral blood flow (CBF) four times each during euglycemia (5.2 ± 0.2 mmol/liter) and hypoglycemia (3.0 ± 0.3 mmol/liter) in nine normal human volunteers. Autonomic responses during hypoglycemia were manifested by increases in neurogenic symptoms, heart rate, and plasma levels of epinephrine, norepinephrine, and pancreatic polypeptide. Typical symptoms of hypoglycemia were mild, and none reflected evidence of cognitive or emotional stress. Quantitative CBF fell 6–8% in the cerebrum, brainstem, and cerebellum. Analysis of regional CBF differences identified neuronal activation during hypoglycemia in bilateral MPFC (areas 24 and 32) and bilateral thalamus. These results provide evidence that the MPFC participates in the autonomic responses to simple physiological stimuli in humans.
Stable down-regulation of human polynucleotide kinase enhances spontaneous mutation frequency and sensitizes cells to genotoxic agents
Authors: Rasouli-Nia Aghdass , Karimi-Busheri Feridoun , Weinfeld Michael
Published: April 2004

Human polynucleotide kinase (hPNK) is a 57.1-kDa monomeric protein with conserved motifs associated with phosphatase and kinase activities. hPNK catalyzes phosphorylation of 5′-DNA termini and dephosphorylation of 3′-DNA termini. Previous studies, employing cell-free systems, have suggested that hPNK participates in the repair of DNA strand breaks. To better define the cellular function of hPNK, a double-stranded small-interfering RNA molecule designed to stably target hPNK transcription was introduced into A549 human lung adenocarcinoma cells. The small-interfering RNA suppressed hPNK gene expression by at least 80–90%. These cells exhibited a 7-fold higher spontaneous mutation frequency based on the development of resistance to ouabain; elevated sensitivity to a broad range of genotoxic agents including γ-radiation, UVC radiation, methyl methanesulfonate, hydrogen peroxide, and camptothecin; and slower repair of radiation-induced DNA strand breaks. These findings underscore the importance of hPNK in the maintenance of DNA integrity after damage induced by endogenous and exogenous agents.
The Dynamics of the Singapore Private Housing Market
Authors: Tu Yong
Published: April 2004

In this paper, a dynamic stock flow model is modified and applied to the Singapore private housing market. Two empirical models are then constructed, which offer an explanation for the dynamic patterns of both real private housing prices and new housing construction. In the long run, movements in the real GDP per capita and the total housing stock are found to have significant impacts on real housing prices, while the user cost, the public resale housing prices and the autocorrelation of housing prices with one lag explain most of the short-run dynamics of real housing prices. On the supply side, the long-run price elasticity of new housing construction is 1.31. It is also found that long-run new housing construction drops 6.5 per cent for every 1 per cent increase in the total housing stock.
Early Illustrated Manuscripts of Kashifi's Akhlāq-i Muḥsinī
Authors: Golombek Lisa
Published: April 2004

Of the Many Recorded Manuscripts of Husayn Vaᶜiz-i Kashifi's Treatise on ethics, Akhlāq-i Muḥinī, only six were planned to have illustrations to the text. The manuscript bearing what is ostensibly the earliest date (900/1494-95), was acquired by the Royal Ontario Museum in 1997. It opens with a shamsah, inscribed with a dedication to the Timurid prince Abu’l-Muhsin, and containing the date 900 in numerals (fig. 1). On the last folio, a quatrain relating to the year of composition of the treatise contains a chronogram as well as the date 900 in numerals. The abjad date can, however, be read either as “900” or “907,” and Maria Subtelny has demonstrated convincingly that the latter date must be the correct one, as the text contains a reference to the reconciliation of Abu’l-Muhsin and his father Sultan-Husayn, which took place around 906/1500. Therefore, the work could not have been composed in 900 A.H., and, consequently, the attribution of the Toronto manuscript to this date is false.
To Preserve and Protect: Husayn Vaᶜiz-i Kashifi and Perso-Islamic Chancellery Culture
Authors: Mitchell Colin Paul
Published: April 2004

It is Generally Agreed that the Beginning of the Persian Literary Renaissance of the tenth–eleventh centuries was concomitant with the emergence of a bureaucratic tradition that had its roots in pre-Islamic Sasanian Iran. The avatars of these bureaucratic principles in medieval Perso-Islamic history—Nizam al-Mulk, Rashid al-Din, Nasir al-Din al-Tusi, to name the most famous—were trained in Arabic and Persian, wrote scholarly treatises on a wide array of religious, philosophical, and scientific topics, and advocated, among other things, the need for responsible rule and consistent administration according to Islamic law and custom. These admonitions were generally directed at their Turkic and Mongol dynastic patrons whose steppe traditions were often at cross-purposes with the running of a sedentary society that depended on irrigated agriculture, commerce, public works, and systems of taxation. Prominent Persian bureaucrats and their descendents undertook these duties and were able to accrue considerable power and wealth, but often at a high cost when we read of the fates of Rashid al-Din, Saᶜd al-Dawla and Juvayni.
Imitation and Innovation in Timurid Poetics: Kashifi'sBadāyiᶜ al-afkārand its predecessors,al-MuᶜjamandḤadāᵓiq al-siḥr
Authors: Simidchieva Marta
Published: April 2004

Husayn Vaᶜiz-i Kashifi, The Persian Prose-Writer Par Excellence of the ninth/fifteenth century, did not compose his treatiseBadāyiᶜ al-afkār fī ṣanāyiᶜ al-ashᶜār[Wondrous Thoughts on Poetical Tropes] to compensate for the lapses of his predecessors, or to make a groundbreaking contribution to the Persian literary sciences. His stated purpose, at least, was rather prosaic.Badāyiᶜ al-afkārwas Kashifi's calling card to the new Timurid ruler Sultan-Husayn Bayqara (r. 873/1469–911/1506), which—so he hoped—would secure his place among the literary experts at the Timurid court. That much we know from the author's introduction to the treatise. At the time of Sultan-Husayn Bayqara's ascension to the throne, Herat was at the peak of its glory.
A Late Medieval Persian Summa on Ethics: Kashifi's Akhlāq-i Muḥsinī
Authors: Subtelny Maria E.
Published: April 2004

The Akhlāq-i Muḥsinī of Husayn Vaᶜiz-i Kashifi in Many Respects Represents a late medieval summa, or codification, of the Persian genre of ethical and advice literature. Designated variously as andarz, pand, naṣīḥat, siyar and akhlāq, the genre of political advice literature is an ancient one in Persian culture, going back to Late Antiquity and exhibiting concordance with Greek and Indian sources. Most works of Sasanian political wisdom literature, such as the Advices of Anushirvan, Buzurjmihr, and Ardashir, as well as those attributed to the ancient Greek sages Aristotle, Plato, and others, are of indeterminate authorship. Many have been preserved only in late manuscript copies dating from the twelfth and thirteenth centuries, and some, like the famous Letter of Tansar, may even have been composed in later periods.
Structure of Binary CaO–Al2O3 and SrO–Al2O3 Liquids by Combined Levitation-Neutron Diffraction
Authors: Weber J.K.R. , Benmore C.J. , Tangeman J.A. , Siewenie J. , Hiera K.J.
Published: April 2004

The total structure factors, S(Q) of 50:50 mole% CaO:Al2O3- and 67:33 mole% SrO:Al2O3-composition liquids have been determined by neutron diffraction. Measurements were made on laser beam-heated liquids at 2000–2100 K held in an aerodynamic levitator. Pure vanadium levitation nozzles were used. Reduction of the nozzle wall thickness decreased attenuation of scattered neutrons to give a two-fold increase in signal intensity. The liquids are comprised of predominantly 4-coordinated aluminum and 6- and higher-coordinated group II metal ions.
Inelasticity Effect on Neutron Scattering Intensities of the Null-H2O
Authors: Kameda Y. , Sasaki M. , Usuki T. , Otomo T. , Itoh K. , Suzuya K. , Fukunaga T.
Published: April 2004

Time-of-flight (TOF) neutron scattering measurements have been carried out for liquid null-H2O, in which the average coherent scattering length of hydrogen atoms is zero. In order to determine the inelasticity effect depending on both the scattering angle and the neutron flight path ratio, γ[=ls/(l0+ls), l0 and ls denote the moderator-sample and sample-detector distances, respectively], neutron scattering measurements have been performed using three neutron spectrometers, HIT-II, RAT, and SWAN, installed at KENS, Tsukuba, Japan. The self-scattering intensity for the null-H2O was derived by subtracting the known O–O partial structure factor from the observed scattering cross-section. It has been revealed that the magnitude of the inelasticity distortion involved in the self-scattering term is still significant even at a smaller scattering angle than that expected from the first-order inelasticity correction formulas proposed in the literature. The inelasticity distortion in the self-scattering term is found to be preferably reduced by applying the small flight path ratio. An empirical but useful correction procedure for the inelasticity effect is developed using the self-scattering intensities observed for the null-H2O. The present correction procedure is applied to the scattering cross-section observed for aqueous 3 mol% alanine solution which involves 20% H of exchangeable hydrogen atoms, and to the first-order difference function ΔH(Q) observed for 4 mol% lithium benzoate heavy water solutions in which H/D isotopic substitution has been applied for benzyl-hydrogen atoms within the benzoate ion. The results indicate that the present inelasticity correction procedure works satisfactorily for the scattering intensity from the aqueous solution containing H atoms.