bluuebunny/crossref_metadata_2025 huggingface dataset:
Thymidylate synthase inhibition triggers glucose‐dependent apoptosis in p53‐negative leukemic cells
Authors: Muñoz-Pinedo Cristina , Robledo Gema , López-Rivas Abelardo
Published: July 2004

Chemotherapeutic drugs that inhibit the synthesis of DNA precursor thymidine triphosphate cause apoptosis, although the mechanism underlying this process remains rather unknown. Here, we describe thymineless death of human myeloid leukemia U937 cells treated with the thymidylate‐synthase inhibitor 5′‐fluoro‐2′‐deoxyuridine (FUdR). This apoptotic process was shown to be independent of p53, reactive oxygen species generation and CD95 activation. Caspases were activated downstream of cytochrome c but upstream of mitochondrial depolarization. Furthermore, FUdR‐induced apoptosis required the presence of glucose in the culture medium at a step upstream of the release of cytochrome c from mitochondria.
Aldose reductase regulates TNF‐α‐induced cell signaling and apoptosis in vascular endothelial cells
Authors: Ramana Kota V , Bhatnagar Aruni , Srivastava Satish K
Published: July 2004

In this study, we examined the role of aldose reductase (AR) in regulating the cytotoxic effects of TNF‐α on human umbilical vein endothelial cells. Inhibition of AR by sorbinil or tolrestat prevented TNF‐α‐induced increase in Bax and Bak and the downregulation of Bcl‐2. Inhibition of AR abrogated AP‐1 DNA binding activity and prevented the activation of caspase‐3, JNK, and p38 MAPK in cells stimulated by TNF‐α. Exposure to TNF‐α also induced apoptotic cell death, which was attenuated by AR inhibition or antisense ablation. These observations suggest that AR is a critical regulator of TNF‐α‐induced apoptotic signaling in endothelial cells.
Inhibitory action of novel aromatic diamine compound on lipopolysaccharide‐induced nuclear translocation of NF‐κB without affecting IκB degradation
Authors: Shin Hyun-Mo , Kim Min-Hee , Kim Byung Hak , Jung Sang-Hun , Kim Yeong Shik , Park Hye Ji , Hong Jin Tae , Min Kyung Rak , Kim Youngsoo
Published: July 2004

4‐Methyl‐N
1‐(3‐phenyl‐propyl)‐benzene‐1,2‐diamine (JSH‐23) is a novel chemically synthetic compound. The aromatic diamine JSH‐23 compound exhibited inhibitory effect with an IC50 value of 7.1 μM on nuclear factor (NF)‐κB transcriptional activity in lipopolysaccharide (LPS)‐stimulated macrophages RAW 264.7, and interfered LPS‐induced nuclear translocation of NF‐κB without affecting IκB degradation. This mechanism of action is very rare for controlling NF‐κB activation. Furthermore, the compound inhibited not only LPS‐induced expressions of tumor necrosis factor‐α, interleukin (IL)‐1β, IL‐6 and inducible nitric oxide synthase and cyclooxygenase‐2 but also LPS‐induced apoptosis of the RAW 264.7 cells.
Variant colourations of Atlantic cod (Gadus morhua) in Newfoundland and Labrador nearshore waters
Authors: Gosse Karen R. , Wroblewski Joseph S.
Published: July 2004

Adult cod (Gadus morhua) inhabiting continental shelf waters of the Northwest Atlantic typically display a countershaded colouration: a dark back gradating to a light underbelly. Some cod in Newfoundland and Labrador inshore waters have predominantly brown or red pigmentation. Cod inhabiting Gilbert Bay in Labrador often have golden-brown colouration, likely the result of an invertebrate diet rich in carotenoids, and are known in the vernacular as the “golden cod of Labrador”. To determine the stability of these variant colourations, we captured cod from Gilbert Bay, held them in a net pen and fed them a diet of fish. Over the 12-week experimental period, the variant coloured cod lost much of their brown or red pigmentation, and became countershaded. Because of its impermanence when cod switch from invertebrate to fish prey, variant colouration of cod can provide only provisional information about stock origin.
Turning away from whiplash. An EMG study of head rotation in whiplash impact
Authors: Kumar Shrawan , Ferrari Robert , Narayan Yogesh
Published: July 2004

Objective. To determine the response of the cervical muscles to whiplash‐type perturbations through low‐velocity frontal impacts when the head is rotated to the right and left.

Methods. Twenty healthy volunteers were subjected to increasing acceleration in low‐velocity frontal impacts, randomly with head rotated either left or right. Bilateral EMG of the sternocleidomastoids, trapezii, and splenii capitis and acceleration of the sled, torso, and head were recorded.

Results. With either direction of head rotation at the time of impact, the muscle responses increased with increasing levels of acceleration (p < 0.01). The time to onset and peak electromyogram for all muscles progressively decreased with increasing levels of acceleration. With the head rotated to the left, the left trapezius generated 77% of its maximal voluntary contraction (MVC) EMG (more than double the response of other muscles). In comparison, the right trapezius generated only 33% of its MVC. The right sternocleidomastoid (25%) and left splenius muscles (32%), the ones responsible for head rotation to the left, were more active than their counterparts (the left sternocleidomastoid generated only 5% of its MVC EMG and the right splenius 9%). On the other hand, with the head rotated to the right, the right trapezius generated 71% of its MVC EMG, while the left trapezius generated only 30% of this value. Again, the left sternocleidomastoid (27% of its MVC EMG) and right splenius (28% of its MVC EMG), being responsible for head rotation to the right, were more active than their counterparts (the right sternocleidomastoid generated only 4% of its MVC EMG and the left splenius 13%).

Conclusions. Frontal impacts tend to generate the most muscle activity in the ipsilateral trapezius muscle, increasing the risk of their injury. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Geochemical characterization, correlation, and optical dating of tephra in alluvial sequences of central western Argentina
Authors: Toms Phillip S. , King Matthew , Zárate Marcelo A. , Kemp Rob A. , Foit Franklin F.
Published: July 2004

The synthesis of paleoclimatic archives provided by loess and alluvial sequences of central Argentina has been hindered by the lack of a cohesive lithostratigraphic framework extending across the Chaco–Pampean plains and catchments of the Rios Desaguadero, Colorado, and Negro. This condition originates in part from the dearth of absolute chronological controls. The occurrence of discrete tephra layers across this region may provide an opportunity to address this deficiency if a tephrochronological framework can be established. The potential of such a project is assessed within the context of a pilot study constrained within alluvial sequences of central western Argentina proximal to potential source vents in the Southern Volcanic Zone. The intersite discrimination and correlation of tephra layers on a geochemical basis is examined, with indirect chronological control for the eruption of each generated by optical dating. Alluvial sediments on either side of each of five tephra units at a type site were dated using the optically stimulated luminescence of fine-silt-sized quartz, thus providing an age control on each tephra (ca. 24,000, 30,000, 32,000, 39,000, and 48,000 yr). The geochemical composition of each tephra was derived. Using these data, tephra layers at other sites in the study area were geochemically analyzed and in instances of statistical concordance in major oxide structure, correlated to the type site and therefore ascribed ages. This methodology identified a further sixth volcanic event between ca. 24,000 and 30,000 yr not registered by type-site tephras. The extension of this initial tephrochronological framework beyond the alluvial sequences of central western Argentina is encouraged by the occurrence of geochemically distinct tephra verified and dated in this study.
INTRODUCTION TO WOMEN, FAMILY AND INHERITANCE IN CHINA AND JAPAN
Authors: Goody Jack
Published: July 2004

Both papers in this section are concerned with issues of women's access to property and marriage in the medieval period, McDermott's with China (and in particular the study by Bettine Birge), and Kurushima's with Japan (and more especially with the marriage strategies of a political kind among the élite).
WOMEN OF PROPERTY IN CHINA, 960–1368: A SURVEY OF THE SCHOLARSHIP
Authors: McDermott Joseph P.
Published: July 2004

The issue of women's property rights during the Song dynasty has been heatedly debated for over half a century. First in Japan, and then in China, Taiwan and the West, scholars have developed strikingly divergent views of the legal and social dimensions of Song women's claims to property and control over their remarriage as widows. This article discusses and assesses the different views, particularly those of Bettine Birge in her recent book-length analysis of the topic. In siding largely with earlier studies that stressed Song women's legally backed rights to property as daughters, wives and widows, Birge's work provides the most comprehensive and persuasive treatment of this debate in any language. In addition, she discusses the fate of Chinese widows, accustomed to remarrying under favourable terms in the Song, and then suffering during the Yuan serious restrictions on their options for remarriage as well as on their property rights. The turning point, according to this book, was the merger of Mongol government and neo-Confucian court interests in the late thirteenth and early fourteenth century, thereby depriving women of many powers they had acquired in the Song.
MARRIAGE AND FEMALE INHERITANCE IN MEDIEVAL JAPAN
Authors: Kurushima Noriko
Published: July 2004

This paper discusses the status of women in late medieval Japan through an examination of marriage and inheritance, in particular through the concept of ie (the household as a basic social unit). It casts a fresh view on the relationship between the ie and women, and in the process refutes the assumption of Takamure Itsue that the emergence of the ie prompted an oppressive form of marriage that deprived women of freedom, rights and a claim to property. Taking class distinctions into consideration, the paper reviews the legal, social and economic position of women. It shows that the ie was not an oppressor of women at its inception, but as time passed the independence of the ie was eroded from within and without, and in the process women were gradually excluded from positions of power. The paper also takes a close look at various patterns of marriage in different social classes and at inheritance. Even though primogeniture concentrated the ie property in the hands of the male heir, female inheritance continued well into the sixteenth century. The paper concludes that the position of women in modern Japan has its roots in the late medieval period, and criticizes Takamure for viewing the late medieval ie from a modern perspective.
“ETERNAL FLAMES”: SUICIDE, SINFULNESS AND INSANITY IN “WESTERN” CONSTRUCTIONS OF SATI, 1500–1830
Authors: Major Andrea
Published: July 2004

In the wake of the immolation of Roop Kanwar in Deorala, Rajasthan, in 1987, sati has re-emerged as a controversial political and social issue in modern India. Many of the terms of the contemporary debate on sati have their roots in the colonial period and are based on assumptions and ideas formulated during the British debate on sati in the early nineteenth century. These ideas were often as much the product of changing British society and its preoccupations as they were the encounter with India, however. This article explores the connotations of changing attitudes to suicide in influencing the nature of British responses to sati. By examining the relationship between attitudes to suicide and changing depictions of sati between 1500–1830, it seeks to undermine the suggestion of a constant western “morality” with regard to sati, depicting instead an encounter with the rite that was bi-directional and fluid with the dichotomy between “East” and “West” cross-cut by a myriad of other issues and concerns.
WAS TRADITIONAL CHINESE LAW A MERE “MODEL”? PART TWO
Authors: Nakamura Shigeo
Published: July 2004

Inside and outside China, it has been widely believed that in premodern China common people did not bring civil cases to magistrate's courts but settled them at the level of their clan, village or guild. However, David C. Buxbaum's research based on the Dan-Xin Archive and Shiga Shu¯zo¯'s study of legal memoranda show that people quite regularly turned to the magistrate's court to resolve civil disputes. During the Qing dynasty, legal cases were divided, not in civil or criminal terms, but according to how serious the offence was. The less-serious offences were civil cases that included disputes concerning marriage and inheritance, land and property, money and loans, and minor battery. Whereas the latter category, criminal cases in today's terms, were handled with the intention of maintaining legal stability, magistrates involved with civil cases tried to strike a reasonable balance by examining each case on an individual basis. However, how the law was applied to civil cases remains a subject for future research.
Übersetzung und Validierung einer Skala zur Messung des organisationsbezogenen Selbstwertes
Authors: Kanning Uwe Peter , Schnitker Ruth
Published: July 2004

Zusammenfassung. Es wird von drei Studien berichtet, die sich mit der Skalenanalyse und Validierung einer übersetzten Skala zur Messung des organisationsbezogenen Selbstwertes (OBSE) beschäftigen. Studie 1 (N = 193 Krankenpflegeschüler) widmet sich der Skalenanalyse und untersucht die Zusammenhänge zwischen OBSE und dem allgemeinen Selbstwert sowie drei organisationsbezogenen Variablen (Zufriedenheit bzw. Verbundenheit mit der Organisation, Identifikation mit der eigenen Berufsgruppe). In Studie 2 (N = 163 Krankenpflegekräfte) wird die Konstruktvalidität der Skala in Bezug auf acht Variablen (“Big Five“, Teamorientierung, Ängstlichkeit, allgemeiner Selbstwert) untersucht. Darüber hinaus gehen wir der Frage nach, inwieweit der OBSE im Sinne der inkrementellen Validität einen signifikanten Beitrag zur Vorhersage der Arbeitzufriedenheit leistet. In Studie 3 (N = 111 Krankenpflegekräfte) überprüfen wir die Konstruktvalidität der Skala in Bezug auf vier Selbstkonzeptvariablen (allgemeiner Selbstwert, internale Kontrollüberzeugung, Selbstwirksamkeit, Neurotizismus) und untersuchen die inkrementelle Validität des OBSE im Hinblick auf Arbeitszufriedenheit und Leistung. Die Ergebnisse unterstreichen die Validität der OBSE-Skala.
Wissenschafts-Praxis-Forum
Authors: Benedikt Hans-Peter , Mittmann Sebastian
Published: July 2004

Zusammenfassung. Das Berufsbild Bankkauffrau/-mann hat sich in den vergangenen Jahren grundlegend verändert. Im Mittelpunkt der Ausbildung steht heute die Entwicklung kunden- und marktorientierter Handlungskompetenz. Der vorgelegte Praxisbericht beschreibt, wie die Stadtsparkasse Dresden das angewandte Auswahlverfahren für Auszubildende einer Evaluation unterzieht und die Frage zu klären versucht, inwieweit die für den Berufserfolg wichtigen Kriterien bereits vor Ausbildungsbeginn prognostiziert werden können. Die dargestellten Evaluationsergebnisse zeigen erwartungsgemäß für die Prädiktoren des Auswahlverfahrens befriedigende, aber noch ausbaubare Ergebnisse. Insbesondere die Kriterien Berufsschulnoten, IHK-Noten, Noten im innerbetrieblichen Fachunterricht und Ergebnis im unternehmensinternen Azubiranking lassen sich zuverlässig vorhersagen. Für die Mitarbeiterbeurteilungen während der Ausbildung und für das Prüfungsergebnis nach dem innerbetrieblichen Verkaufs- und Verhaltenstraining werden keine wirksamen Prädiktoren nachgewiesen. Im Zuge der weiterführenden Berechnungen wird deutlich, dass die Schwachpunkte der Evaluationsergebnisse durch eine Fokussierung auf den Notendurchschnitt in den naturwissenschaftlichen Schulfächern der Bewerber und der Berechnung eines Kopfnotendurchschnitts kompensiert werden könnten. Die Untersuchungsergebnisse zeigen zudem, dass eine weitere Standardisierung des Verfahrens die Genauigkeit der Prognose weiter erhöhen könnte.
Videokonferenzen in Organisationen: Chancen, Risiken und personalpsychologisch relevante Anwendungsfelder
Authors: Wegge Jürgen , Bipp Tanja
Published: July 2004

Zusammenfassung. Arbeit mit verschiedenen Formen von Videokonferenzsystemen nimmt stetig zu. Neben der Teilnahme an Konferenzen ermöglichen insbesondere pc-basierte Systeme vielfältige Interaktionsprozesse (z. B. Beratung, Befragung, Anweisung, Datentransfer), die sowohl zwischen organisationsinternen (Vorgesetzte, Mitarbeiter, Teleheimarbeiter etc.) als auch zwischen organisationsexternen Akteuren wie z. B. Kunden, Klienten, Bewerbern oder Patienten stattfinden können. Weil Videokonferenzen (VK) im Vergleich zu herkömmlichen Kommunikationssituationen (z. B. Brief, Telefon, E-Mail) komplexere Interaktionsformen unterstützen und mit multimedialen VK nachhaltigere Wirkungen erzielt werden können, ergeben sich für die Personalpsychologie interessante neue Anwendungsmöglichkeiten. In diesem Übersichtsartikel wird zusammengefasst, was man über die aktuelle Verbreitung und allgemeinen Wirkungen (Chancen, Risiken) von VK weiß. Ferner wird bilanziert, welche Erkenntnisse mit Blick auf vier personalpsychologisch relevante Anwendungsgebiete - Mitarbeiterführung, Beratung, Personalentwicklung und Personalmarketing - heute vorliegen. Wenngleich der schon häufig vorhergesagte Boom von VK in der organisationalen Praxis noch auf sich warten lässt, ist es Zeit, die besonderen Probleme und Chancen dieser neuen Technik in der personalpsychologischen Arbeit mehr zu beachten.
A hydrological digital elevation model for freshwater discharge into the Gulf of Alaska
Authors: Wang Jia , Jin Meibing , Musgrave David L. , Ikeda Moto
Published: July 2004

Freshwater discharge into the Gulf of Alaska (GOA) has an important effect on coastal circulation. In order to incorporate freshwater discharge into a three‐dimensional ocean circulation model with both point sources (big rivers) and line sources (gridded coastlines) a digital elevation model (DEM) was developed to simulate freshwater discharge into the GOA under forcing of daily air temperature and precipitation data from National Centers for Environmental Predication/National Center for Atmospheric Research reanalysis during 1958–1998. This GOA‐DEM includes glacier, snow storage, and melting processes. Coastal freshwater discharge into the GOA displays a very strong seasonal cycle and interannual variability. The comparison of simulated runoff with gauged (observed) river discharge was conducted for two major rivers (Copper River and Susitna River), showing a good agreement on seasonal cycle and interannual variability. The simulated annual mean of the total freshwater discharge into the GOA ranges from 19,000 to 31,000 m3 s−1 (with a mean of 23,100 m3 s−1) for the period 1958–1998. In the winter season (November to April), precipitation is mainly stored as snow, and freshwater discharge remains as a small base flow with some occasional changes due to short‐term temperature increase. Freshwater discharge starts to rise sharply from May because of increasing precipitation and above‐freezing temperatures and remains high from June through September because of snowmelt and some melting glaciers. In October the discharge decreases rapidly, to a basic flow in December as the temperature drops below the freezing point. Freshwater discharge into the GOA can be divided into the point sources (big rivers) and the line sources (ungauged numerous small streams and creeks due to melting of snow and glaciers). The model shows that five major rivers (point sources) account for about 50.6% of the total drainage areas, while the line source accounts for 49.4% of the drainage area. However, our new finding is that the point sources only account for 26%, while the line sources contribute 74% to the total runoff. Thus discharge from line sources (ungauged small rivers, streams, and creeks) is 2.8 times greater than from the point sources (five large rivers).
Measurement of formaldehyde, nitrogen dioxide, and sulfur dioxide at Whiteface Mountain using a dual tunable diode laser system
Authors: Li Y. Q. , Demerjian K. L. , Zahniser M. S. , Nelson D. D. , McManus J. B. , Herndon S. C.
Published: July 2004

An application of a dual tunable diode laser absorption spectrometer (TDLAS) to ambient measurements of formaldehyde (HCHO), nitrogen dioxide (NO2) and sulfur dioxide (SO2) is described. During the PM2.5 Technology Assessment and Characterization Study‐New York (PMTACS‐NY) 2002 intensive field campaign at Whiteface Mountain, New York, a dual TDLAS was deployed during a field instrument comparison study along with five other state‐of‐the‐art trace gas measurement techniques. Prior to the field study, a thorough laboratory characterization of the instrument was undertaken to establish the optimum operational conditions including the selection of absorption features and the implementation of continuous laser frequency locking and rapid background subtraction. The Allan variance method was used to determine the optimal background subtraction cycle and to evaluate instrument performance. During the field campaign, measurements of HCHO, NO2 and SO2 were made by the TDLAS with the measurement precisions (1‐min time interval, 1σ) of 80 ppt, 30 ppt and 40 ppt, respectively. The HCHO time series indicated a high variability of HCHO concentrations ranging from below the detection limit to 5 ppbv. The diurnal cycle of HCHO measurements showed higher concentrations during the late afternoon and early morning hours. The measured NO2 concentrations varied from less than the detection limit to the maximum of 25 ppbv. Broad NO2 plumes from long‐distance transport of air masses and as well as high spikes from local pollution sources were observed during the campaign. The measured SO2 results also show high variability with the average concentration of 0.75 ± 0.95 ppbv (1σ).
A modeling study of an East Asian convective complex during March 2001
Authors: Hitchman Matthew H. , Buker Marcus L. , Tripoli Gregory J. , Pierce R. B. , Al‐Saadi J. A. , Browell E. V. , Avery Melody A.
Published: July 2004

During March–April 2001 the University of Wisconsin Nonhydrostatic Modeling System (UWNMS) was used to provide flight planning and estimation of ozone flux into the troposphere over East Asia in support of the Transport and Chemical Evolution over the Pacific (TRACE‐P) mission. On 24 March a convective complex developed in eastern China and propagated eastward over the Pacific south of Japan. Aircraft and satellite observations, together with the UWNMS simulations, captured this convective event, which first entrained urban boundary layer air over Asia and then marine boundary layer air over the Pacific. The convective updraft split the subtropical westerly jet, deformed the tropopause upward, radiated gravity waves into the stratosphere, and induced a ring of stratospheric ozone to descend around its periphery into the middle troposphere. The DC‐8 observations and UWNMS show a vault of moderate ozone (∼65 ppbv) in the 8–12 km layer within the convection, with high stratospheric values (∼100 ppbv) subsiding around the periphery into the troposphere near 6.5 km. A new two‐scale method for diagnosing cross‐tropopause ozone flux is compared with an annular volume estimate. During this 24 hour convective event, ∼0.8 Tg ozone entered the troposphere from the stratosphere, comparable in magnitude to ozone fluxes in midlatitude cyclones.
MATADOR 2002: A pilot field experiment on convective plumes and dust devils
Authors: Renno Nilton O. , Abreu Vincent J. , Koch Jacquelin , Smith Peter H. , Hartogensis Oscar K. , De Bruin Henk A. R. , Burose Dirk , Delory Gregory T. , Farrell William M. , Watts Christopher J. , Garatuza Jaime , Parker Michael , Carswell Allan
Published: July 2004

Recent research suggests that mineral dust plays an important role in terrestrial weather and climate, not only by altering the atmospheric radiation budget, but also by affecting cloud microphysics and optical properties. In addition, dust transport and related Aeolian processes have been substantially modifying the surface of Mars. Dusty convective plumes and dust devils are frequently observed in terrestrial deserts and are ubiquitous features of the Martian landscape. There is evidence that they are important sources of atmospheric dust on both planets. Many studies have shown that on a small scale, dust sourcing is sensitive to a large number of factors, such as soil cover, physical characteristics, composition, topography, and weather. We have been doing comparative studies of dust events on Earth and Mars in order to shed light on important physical processes of the weather and climate of both planets. Our 2002 field campaign showed that terrestrial dust devils produce heat and dust fluxes two and five orders of magnitude larger than their background values. It also showed that charge separation within terrestrial dust devils produces strong electric fields that might play a significant role in dust sourcing. Since Martian dust devils and dust storms are stronger and larger than terrestrial events, they probably produce even stronger fluxes and electric fields.
Phase signatures in acoustic‐seismic land mine detection
Authors: Wang Tsaipei , Keller James M. , Gader Paul D. , Hocaoglu A. Koksal
Published: July 2004

The utility of acoustic‐to‐seismic coupling systems for land mine detection has been clearly established with potential as either a primary or confirmation sensor system. They can detect very low metal content mines that are difficult for ground‐penetrating radar detection. For most applications, only the magnitude of the surface velocity is used to construct recognition algorithms. Recently, we introduced phase‐based features in the classification scheme, significantly lowering false alarm rates at given detection probabilities. In this paper we introduce modeling equations that explain the phase features. We also describe the image processing techniques applied to velocity data collected in the time domain.
Non‐Fickian transport in homogeneous unsaturated repacked sand
Authors: Bromly Melissa , Hinz Christoph
Published: July 2004

It is commonly assumed a priori that solute transport experiments conducted in homogeneously repacked laboratory columns can be described by the advective‐dispersive (AD) or single‐rate mobile‐immobile (MIM) transport model. To investigate this, nonreactive transport through macroscopically homogeneous repacked unsaturated sand was studied at two water contents using laboratory columns of diameter of 11 cm and lengths of 10, 20, and 40 cm. Non‐Fickian behavior was found to dominate transport at this scale, with long breakthrough curve (BTC) tailing persistent over the range of column lengths tested. Measured BTC tails were well described by the single‐rate MIM model at each depth; however, over the range of travel distances studied BTC tailing was better explained as a result of stochastic‐convective (SC) transport or continuous time random walk (CTRW). The SC model was applied using the BTC measured at 10 cm as the probability density function to make predictions to subsequent depths. The CTRW model spreading parameter (β) remained approximately constant across the range of both travel distances and water contents considered. It is concluded that the assumption of a single‐rate MIM model cannot be made a priori for macroscopically homogeneous unsaturated sands. In this case, variability between replicates prevented identification of whether a SC transfer function or CTRW provided the best description of transport. These results demonstrate the variability in transport as a result of heterogeneities in column packing, even for macroscopically homogeneous sand, and emphasize the importance of studying transport over a range of travel distances in order to allow prediction of transport.
The limited growth of vegetated shear layers
Authors: Ghisalberti M. , Nepf H. M.
Published: July 2004

In contrast to free shear layers, which grow continuously downstream, shear layers generated by submerged vegetation grow only to a finite thickness. Because these shear layers are characterized by coherent vortex structures and rapid vertical mixing, their thickness controls exchange between the vegetation and the overlying water. Experiments conducted in a laboratory flume show that the growth of these obstructed shear layers is arrested once the production of shear‐layer‐scale turbulent kinetic energy (SKE) is balanced by dissipation of SKE within the canopy. This equilibrium condition, along with a mixing length closure scheme, was used in a one‐dimensional numerical model to predict the mean velocity profiles of the experimental shear layers. The agreement between model and experiment is very good, but field application of the model is limited by a lack of description of the drag coefficient in a submerged canopy.
Nitrogen loss rates in streams: Scale‐dependence and up‐scaling methodology
Authors: Lindgren G. A. , Destouni G.
Published: July 2004

We show that the large spatial aggregation of model parameters in common catchment scale nitrogen budget modeling leads to artifacts that may, for instance, be a factor in explaining reported decreases of calibrated in‐stream nitrogen loss rates, λs*, with increasing stream size. In general, the common assumption of a single representative solute travel time for an entire stream reach may lead to considerable underestimation of the actual underlying local biogeochemical loss rate λs by λs*, which increases with actual λs value and/or increasing mean solute travel time and travel time variability in the stream. We propose an up‐scaling methodology to overcome such model artifacts, in form of closed‐form expressions of catchment‐scale, in‐stream nitrogen delivery factors for diffuse and point sources, as functions of local‐scale nitrogen loss rates, λs.
Satellite radar interferometry 1993–1999 suggests deep accumulation of magma near the crust‐mantle boundary at the Krafla volcanic system, Iceland
Authors: de Zeeuw‐van Dalfsen Elske , Pedersen Rikke , Sigmundsson Freysteinn , Pagli Carolina
Published: July 2004

Deep magma accumulation near the crust‐mantle boundary (21 km depth) at the Krafla volcanic system is suggested from InSAR observations. A best fit model, derived from four interferograms covering 1993–1999, comprises an opening dike, representing plate spreading and post‐rifting deformation, and two Mogi sources. A Mogi source deflating at a rate of ∼0.3 × 106 m3/yr coincides with the shallow Krafla magma chamber while a deeper inflating Mogi source, further north, at 21 km depth, inflates at a rate of ∼26 × 106 m3/yr. The inflating source is at or near the crust‐mantle boundary as identified by seismic studies and is interpreted as accumulating magma.
Feasible optimality of vegetation patterns in river basins
Authors: Caylor Kelly K. , Scanlon Todd M. , Rodriguez‐Iturbe Ignacio
Published: July 2004

We examine mechanisms leading to organization of vegetation patterns within the channel network structure of a semi‐arid New Mexico river basin under the controlling influence of water stress. We compare the actual pattern of water stress within the basin to patterns resulting from two algorithms of local stress optimization which proceed from an initial fully random vegetation distribution. Here we show that the distribution of vegetation and basin water stress derived from an algorithm that maintains local optimization within the network flow path exhibits considerably better agreement with the actual distribution than one that ignores the network structure of the basin. These results suggest the pattern of actual vegetation observed within the basin corresponds to a condition of feasible optimality in which organization is constrained by the stochastic nature of local interactions mediated by the network configuration. The principles of such organization have important consequences regarding the interaction between land cover change and hydrological dynamics in river basins, as well as the biogeographical evolution of landscapes.
Magnetosphere‐ionosphere coupling by Alfvén waves at midlatitudes
Authors: Lysak R. L.
Published: July 2004

Numerical modeling of magnetosphere‐ionosphere coupling by Alfvén waves has proven to be a valuable tool in describing the propagation and evolution of field‐aligned currents and the magnetic fields produced by these waves as observed on the ground. Although many models of this type have assumed that magnetic field lines penetrate the ionosphere vertically, this assumption is not valid at lower latitudes, where the dipole tilt is significant. This paper presents a new model of this interaction that takes the dipole geometry into account, while including an ionosphere that is radially stratified. Since the orthogonal dipole coordinates that have been used in previous studies do not come to a constant radial distance at the ionosphere, a nonorthogonal system is developed that reduces to the orthogonal system at high altitudes. This model is useful for many different problems of wave coupling and is applied here to the propagation of ducted Pc1 oscillations that can propagate thousands of kilometers across magnetic field lines.
Distributions and fluxes of methane in the East China Sea and the Yellow Sea in spring
Authors: Zhang G. L. , Zhang J. , Kang Y. B. , Liu S. M.
Published: July 2004

Distributions and fluxes of methane were determined during two surveys in March–May 2001 in the Yellow Sea and the East China Sea. Methane concentrations in the surface and bottom waters range from 2.52 to 5.48 and 2.81 to 8.17 nM, respectively. The distributions of methane are influenced obviously by the Yangtze River effluent and Kuroshio water. CH4 input via the Yangtze River is estimated to be 3.17 mol/s, of which a considerable part may be lost by air‐sea exchange during estuarine mixing. Net CH4 flux exported from the shelf to the Kuroshio is about 1.84 mol/s. Methane enrichments in bottom waters occur widely, which reveals sediment sources of CH4. However, the CH4 input from the sediments of the studied region in spring is lower than other shelf regions due to low organic carbon in the sediments and high O2 contents in the water column. The sea‐to‐air methane fluxes are estimated to be 1.36 ± 1.45 and 2.30 ± 2.36 μmol m−2 d−1 using Liss and Merlivat [1986] and Wanninkhof [1992] relationships, respectively, and the estimated spring emission rate of methane ranges from 9.32 × 10−3 to 15.7 × 10−3 Tg CH4 yr−1. However, these estimations suffer from the neglect of seasonal variability and should be taken as a low limit. Therefore more measurement campaigns should be carried out to enhance our understanding of this particular oceanic region.
Periodontal bone loss associated with an improper flossing technique: a case report
Authors: Walters J D , Chang E I
Published: July 2004

Abstract  

Purpose: This article documents a case in which soft tissue and bone damage was associated with a long‐standing habit of improper flossing.

Case description: A 33‐year‐old patient with excellent oral hygiene presented with gingival clefting and an unusual pattern of moderate angular bone loss at several sites. Previous radiographs suggested that some bony lesions had been present for more than 13 years. Examination revealed no evidence that the osseous defects were related to chronic periodontitis or occlusal trauma. The focus of treatment for these chronic injuries was teaching the patient an atraumatic flossing technique.

Conclusion: As the lesions had gone undiagnosed for many years, this case underscores the need to look for clinical signs of floss‐induced damage during periodic examinations.
Constructing an E-Supply Chain at Eastman Chemical Company
Authors: Yen Benjamin , Farhoomand Ali , Ng Pauline
Published: July 2004

Craig Knight, Asia Pacific Digital Business and Customer Services Manager of Eastman Chemical Company, was given a mandate to sell Eastman's philosophy for an integrated electronic supply chain, otherwise known as the Integrated System Solution (ISS), to its business partners in the region, and to encourage adoption. Having invested in a state-of-the-art technical architecture that would support interconnectivity with all parties along the supply chain, Eastman was keen to realise the full benefits to be gained from an integrated e-supply chain on a global scale. Following numerous rounds of discussion with key business partners in the Asia Pacific region, some progress had been made. Nagase & Co., Ltd. of Japan had agreed to adopt ISS connections with Eastman, but had some reservations regarding the extent of integration. Although the benefits of integration were proven, suppliers, customers, distributors and other interested parties were faced with numerous limitations and considerations that would have significant implications on their established business processes and even the shaping of their corporate strategy. Adoption was not a simple choice. Craig understood these shortcomings and was making every effort to ease the adoption process by identifying the longer-term benefits to Nagase and other business partners of applying XML technology to their businesses.
Numerical and experimental studies of long-range magnetic dipolar interactions
Authors: Ledbetter M. P. , Savukov I. M. , Bouchard L.-S. , Romalis M. V.
Published: July 2004

We describe several numerical methods developed to analyze the behavior of spin polarized liquids in the presence of long-range magnetic dipolar interactions and external field gradients. Two of the methods use a discrete lattice of spins. In the first we calculate the magnetic field from the lattice of spins directly, either in the rotating frame, or in the lab frame. In the second method we include the dipolar fields from linear magnetization gradients analytically and calculate the dipolar fields from higher order gradients in Fourier space, where they are a local function of the magnetization. In the third method the magnetization is expanded in a Taylor series and the dipolar fields are calculated analytically for each term. The results of these calculations are compared to experimental data, in which we use two superconducting quantum interference device magnetometers adjacent to a spherical sample of hyperpolarized liquid Xe129 to detect the evolution of magnetization gradients. In particular, we observe an increase by a factor of 100 of the spin dephasing time in a longitudinal magnetic field gradient due to dipolar interactions of the spins. While each of the numerical techniques has certain limitations, they are generally in agreement with each other and with experimental data.
Quantum Monte Carlo study of the reaction: Cl+CH3OH→CH2OH+HCl
Authors: Kollias A. C. , Couronne O. , Lester W. A.
Published: July 2004

A theoretical study is reported of the Cl+CH3OH→CH2OH+HCl reaction based on the diffusion Monte Carlo (DMC) variant of the quantum Monte Carlo method. Using a DMC trial function constructed as a product of Hartree–Fock and correlation functions, we have computed the barrier height, heat of reaction, atomization energies, and heats of formation of reagents and products. The DMC heat of reaction, atomization energies, and heats of formation are found to agree with experiment to within the error bounds of computation and experiment. Møller–Plesset second order perturbation theory (MP2) and density functional theory, the latter in the B3LYP generalized gradient approximation, are found to overestimate the experimental heat of reaction. Intrinsic reaction coordinate calculations at the MP2 level of theory demonstrate that the reaction is predominantly direct, i.e., proceeds without formation of intermediates, which is consistent with a recent molecular beam experiment. The reaction barrier as determined from MP2 calculations is found to be 2.24 kcal/mol and by DMC it is computed to be 2.39(49) kcal/mol.
Thermodynamic and structural properties of repulsive hard-core Yukawa fluid: Integral equation theory, perturbation theory and Monte Carlo simulations
Authors: Cochran T. W. , Chiew Y. C.
Published: July 2004

The thermodynamic and structural properties of purely repulsive hard-core Yukawa particles in the fluid state are determined through Monte Carlo simulation and modeled using perturbation theory and integral equation theory in the mean spherical approximation (MSA). Systems of particles with Yukawa screening lengths of 1.8, 3.0, and 5.0 are examined with results compared to variations of MSA and perturbation theory. Thermodynamic properties were predicted well by both theories in the fluid region up to the fluid–solid phase boundary. Further, we found that a simplified exponential version of the MSA is the most accurate at predicting radial distribution function at contact. Radial distribution function of repulsive hard-core Yukawa particles are also reported. The results show that methods based on MSA and perturbation theory that are typically applied to the attractive hard-core Yukawa potential can also be extended to the purely repulsive hard-core Yukawa potential.
Efficient hybrid density functional calculations in solids: Assessment of the Heyd–Scuseria–Ernzerhof screened Coulomb hybrid functional
Authors: Heyd Jochen , Scuseria Gustavo E.
Published: July 2004

The present work introduces an efficient screening technique to take advantage of the fast spatial decay of the short range Hartree–Fock (HF) exchange used in the Heyd–Scuseria–Ernzerhof (HSE) screened Coulomb hybrid density functional. The screened HF exchange decay properties and screening efficiency are compared with traditional hybrid functional calculations on solids. The HSE functional is then assessed using 21 metallic, semiconducting, and insulating solids. The examined properties include lattice constants, bulk moduli, and band gaps. The results obtained with HSE exhibit significantly smaller errors than pure density functional theory (DFT) calculations. For structural properties, the errors produced by HSE are up to 50% smaller than the errors of the local density approximation, PBE, and TPSS functionals used for comparison. When predicting band gaps of semiconductors, we found smaller errors with HSE, resulting in a mean absolute error of 0.2 eV (1.3 eV error for all pure DFT functionals). In addition, we present timing results which show the computational time requirements of HSE to be only a factor of 2–4 higher than pure DFT functionals. These results make HSE an attractive choice for calculations of all types of solids.
Theoretical analysis of singlet and triplet excited states of nickel porphyrins
Authors: Patchkovskii Serguei , Kozlowski Pawel M. , Zgierski Marek Z.
Published: July 2004

Local density and generalized gradient approximation time-dependent density functional methods have been used for calculation of the singlet and triplet excited states of nickel–porphine, Ni–tetraphenyloporphine, and Ni–octaethyloporphyrine. Special attention is paid to metal–ligand transitions and d–d transitions. It is shown that the lowest exited singlet states of the three compounds can be described as a transfer of an electron from the porphine ring to the dx2−y2 orbital of the nickel atom. On the other hand, the lowest excited triplet state arises from promotion of an electron between two nickel d orbitals, an occupied dz2 and an empty dx2−y2. It is proposed that a rapid quenching of the excited singlet states is due to an ultrafast intersystem crossing between Eg1 and Eg3 or B1g3 states.
Aging correlation functions for blinking nanocrystals, and other on–off stochastic processes
Authors: Margolin G. , Barkai E.
Published: July 2004

Following recent experiments on power law blinking behavior of single nanocrystals, we calculate two-time intensity correlation functions 〈I(t)I(t+t′)〉 for these systems. We use a simple two state (on and off) stochastic model to describe the dynamics. We classify possible behaviors of the correlation function and show that aging, e.g., dependence of the correlation function on age of process t, is obtained for classes of the on time and off time distributions relevant to experimental situation. Analytical asymptotic scaling behaviors of the intensity correlation in the double time t and t′ domain are obtained. In the scaling limit 〈I(t)I(t+t′)〉→h(x), where four classes of behaviors are found: (i) finite averaged on and off times x=t′ (standard behavior); (ii) on and off times with identical power law behaviors x=t/t′ (case relevant for capped nanocrystals); (iii) exponential on times and power law off times x=tt′ (case relevant for uncapped nanocrystals); (iv) for defected off time distribution we also find x=t+t′. Origin of aging behavior is explained based on simple diffusion model. We argue that the diffusion controlled reaction A+B⇌AB, when followed on a single particle level exhibits aging behavior.
Structures and correlation functions of multicomponent and polydisperse hard-sphere mixtures from a density functional theory
Authors: Yu Yang-Xin , Wu Jianzhong , Xin Yu-Xuan , Gao Guang-Hua
Published: July 2004

The structures of nonuniform binary hard-sphere mixtures and the correlation functions of uniform ternary hard-sphere mixtures were studied using a modified fundamental-measure theory based on the weight functions of Rosenfeld [Rosenfeld, Phys. Rev. Lett. 63, 980 (1989)] and Boublik-Mansoori-Carnahan-Starling-Leland equation of state [Boublik, J. Chem. Phys. 53, 471 (1970); Mansoori et al., J. Chem. Phys. 54, 1523 (1971)]. The theoretical predictions agreed very well with the molecular simulations for the overall density profiles, the local compositions, and the radial distribution functions of uniform as well as inhomogeneous hard-sphere mixtures. The density functional theory was further extended to represent the structure of a polydisperse hard-sphere fluid near a hard wall. Excellent agreement was also achieved between theory and Monte Carlo simulations. The density functional theory predicted oscillatory size segregations near a hard wall for a polydisperse hard-sphere fluid of a uniform size distribution.
Thermally stimulated exoelectron emission from solid neon
Authors: Frankowski Marcin , Savchenko Elena V. , Smith-Gicklhorn Alice M. , Grigorashchenko Oleg N. , Gumenchuk Galina B. , Bondybey Vladimir E.
Published: July 2004

In spite of the negative electron affinity of Ne atoms, appreciable concentrations of electrons can be trapped in solid neon layers formed by depositing the gas on a cold substrate with concurrent electron irradiation. These are trapped at defect sites, and can be promoted into the conduction band in an annealing experiment. They can then recombine with positive charges producing vacuum ultraviolet “thermoluminescence,” but can also be extracted from the solid, and detected as an “exoelectron” current. The thermally stimulated exoelectron emission profiles of the electron current versus temperature reveal two broad features near 7.5 and 10 K. These are shown to correspond to two distributions of electron trapping sites with slightly differing activation energies. For the narrower, higher temperature maximum, an average activation energy of about 23 meV is deduced, in good agreement with predictions based on the theory of electronic defect formation.