bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing Two Approaches for the Assessment of Coping1Marcus Ising is now at the Max Planck Institute for Psychiatry, München. Martin Reuter is now at the Department of Psychology, Justus Liebig University Giessen. Wilhelm Janke is now Professor Emeritus at the Department of Psychology, Julius Maximilians University Würzburg.
Authors: Weyers Peter , Ising Marcus , Reuter Martin , Janke Wilhelm
Published: November 2005

Abstract. This study compared the psychometric properties of two different conceptions of measures of coping. The Stressverarbeitungsfragebogen (SVF) 120 ( Janke & Erdmann, 1997 ) and related inventories measure coping comprehensively over situations and time, however, the Ways of Coping Questionnaire (WCQ; Folkman & Lazarus, 1988 ) measures it for the most stressful situation of the preceding week. We developed a situational WCQ-like version of the SVF120, and 265 participants filled in both the standard SVF120 version (“When I am disturbed, irritated, or upset by something or someone ...”) and the WCQ-like version (“When I was in the situation that disturbed, irritated, or upset me the most during the last 7 days ...”). Results showed comparable reliabilities for the subtests with the two versions correlating between .60 to .80. The VARIMAX rotated factor loadings of a five-factor solution were similar for corresponding factors of both versions. The means of the WCQ version subtests, however, were usually significantly lower. Therefore, both versions are consistent in their measurement of coping, but different instructions lead to quantitative differences in participants' responses.
Calculation of dune morphology
Authors: Tjerry Søren , Fredsøe Jørgen
Published: November 2005

The shape and dimensions of dunes formed in an erodible bed and exposed to flowing water are investigated by using a numerical model. The flow is calculated using a curvilinear flow model, where we combine a k‐ɛ turbulence closure scheme with a sediment‐transport description and the equation of continuity for the sand bed. The complete flow description allows for a discussion about what determines the length of dunes: From the equation of continuity for sediment, it turns out that the sediment transport over dunes is proportional to the local height of the dune. This means that the maximum height of the sand wave occurs at the location of maximum sediment transport. We relate the dune length to the location of maximum sediment transport. It is demonstrated that the effect of streamline curvature is essential for determining the location of maximum sediment transport at low bed shear stresses, due to an overshoot in bed shear stress. For large dimensionless bed shear stresses the downstream decay of turbulence from the former dune is demonstrated to play a major role.
A generalized Exner equation for sediment mass balance
Authors: Paola C. , Voller V. R.
Published: November 2005

The advance of morphodynamics research into new areas has led to a proliferation of forms of sediment mass balance equation. Without a general equation it is often difficult to know what these problem‐specific versions of sediment mass balance leave out. To address this, we derive a general form of the standard Exner equation for sediment mass balance that includes effects of tectonic uplift and subsidence, soil formation and creep, compaction, and chemical precipitation and dissolution. The complete equation, (17), allows for independent evolution of two critical interfaces: that between bedrock and sediment or soil and that between sediment and flow. By eliminating terms from the general equation it is straightforward to derive mass balance equations applicable to a wide range of problems such as short‐term bed evolution, basin evolution, bedrock uplift and soil formation, and carbonate precipitation and transport. Dropping terms makes explicit what is not being considered in a given problem and can be done by inspection or by a formal scaling analysis of the terms. Scaling analysis leads directly to dimensionless numbers that measure the relative importance of terms in the equation, for example, the relative influence of spatial versus temporal changes in sediment load on bed evolution. Combining scaling analysis with time averaging shows how the relative importance of terms in the equation can change with timescale; for example, the term representing bed evolution due to temporal change in sediment load tends to zero as timescale increases.
Entrainment: Local and non‐local turbulence models with double diffusion
Authors: Canuto V. M. , Dubovikov M. S. , Cheng Y.
Published: November 2005

Taylor's entrainment equation contains the entrainment function E that has traditionally been treated heuristically, as attested by 30 different expressions for E(Ri) available in the literature. Using a model independent procedure, we first derive the new relation: E = 2Psh −3 which expresses E in terms of Ps, the shear production (of turbulent kinetic energy) averaged across the interface of the gravity current whose thickness and mean velocity are denoted by h and . Second, using a turbulence model for the turbulence kinetic energy K and its rate of dissipation ɛ (K‐ɛ model, integrated across the flow), we compute Ps to express E in terms of the Richardson number Ri and the density ratio Rρ characterizing double‐diffusion. Third, we show that in the local (along the flow) case, the model reproduces the Ellison and Turner (1959) data while the non‐local case reproduces the data by Princevac et al. (2005) which are up to ten times larger than the ET data.
Titan's stratospheric zonal wind, temperature, and ethane abundance a year prior to Huygens insertion
Authors: Kostiuk T. , Livengood T. A. , Hewagama T. , Sonnabend G. , Fast K. E. , Murakawa K. , Tokunaga A. T. , Annen J. , Buhl D. , Schmülling F.
Published: November 2005

Saturn's satellite, Titan, may have stratospheric winds up to ∼210 m/s, circling Titan in ∼1 terrestrial day compared to its 16‐day rotation. Theoretical models explaining such super‐rotating winds are not well constrained by observations of Titan or a similar slow rotator, Venus. We report measurements taken in December 2003 of zonal wind near Titan's equatorial region, including the Cassini Huygens probe entry latitude. Super‐rotating prograde zonal winds of 190 ± 90 m/s near 220 km altitude are found from Doppler‐shifted C2H6 gas emission near 12 μm, confirming high wind velocity even near the equator. Stratospheric temperature constraints and ethane abundance (8 ± 3 ppm) also are retrieved. Results are not inconsistent with earlier measurements and with recent Cassini CIRS results, but indicate possible variations between Titan's hemispheres. Differences in east and west C2H6 spectral line shapes can be accounted for by different vertical distributions of either C2H6 abundance or temperature or by unidentified dynamical effects.
Onset of power law aftershock decay rates in southern California
Authors: Narteau C. , Shebalin P. , Holschneider M.
Published: November 2005

Aftershocks rates seem to follow a power law decay, but the question of the aftershock frequency immediately after an earthquake remains open. We estimate an average aftershock decay rate within one day in southern California by stacking in time different sequences triggered by main shocks ranging in magnitude from 2.5 to 4.5. Then we estimate the time delay before the onset of the power law aftershock decay rate. For the last 20 years, we observe that this time delay suddenly increase after large earthquakes, and slowly decreases at a constant rate during periods of low seismicity. In a band‐limited power law model such variations can be explained by different patterns of stress distribution at different stages of the seismic cycle. We conclude that, on regional length scales, the brittle upper crust exhibits a collective behavior reflecting to some extent the proximity of a threshold of fracturing.
The 1999 Chi‐Chi, Taiwan, earthquake as a typical example of seismic activation and quiescence
Authors: Chen Chien‐Chih , Rundle John B. , Holliday James R. , Nanjo Kazuyoshi Z. , Turcotte Donald L. , Li Shian‐Chi , Tiampo Kristy F.
Published: November 2005

The Pattern Informatics algorithm, which has recently shown promising performance for earthquake forecasting in Southern California, has been used to detect the locations where precursory seismic activity occurred preceding the 1999 Chi‐Chi, Taiwan, earthquake. Using the Pattern Informatics method as presented in this paper, the epicenter of the Chi‐Chi main shock was found to exhibit signatures of anomalous activity related to the seismic activation and quiescence in the Taiwan region over a time span of about 6 years before the main shock. A strategy of making intermediate‐term earthquake hazard assessment by means of Pattern Informatics is therefore proposed on the basis of retrospective analysis of the Chi‐Chi earthquake.
Early‐time multiphase interactions between basaltic magma and underground openings at the proposed Yucca Mountain radioactive waste repository
Authors: Dartevelle S. , Valentine G. A.
Published: November 2005

We investigate the interaction between Yucca Mountain repository drifts (horizontal emplacement tunnels) and a hawaiitic magma in three scenarios: (1) a single feeder dike that extends above an intersected drift; (2) same as 1 but with an additional secondary dike extending upward from the drift; (3) same as 1 with the drift initially filled with pyroclasts and gas under high pressure which is then decompressed as might happen if some blockage is rapidly removed in the volcanic system above the drift. Our results indicate that the drift is likely to experience dynamic pressure waves from expansion of rising magma and subsequent pyroclastic flows, with a maximum possible dynamic pressure of ∼107 Pa. A secondary dike above the drift has negligible effects upon the flow dynamics. In the third scenario, particles settle fairly quickly along the floor of the drift, suggesting that a swift decompression within the drift will not be able to remove all the magmatic materials.
Seismicity increase after the construction of the world's tallest building: An active blind fault beneath the Taipei 101
Authors: Lin Cheng‐Horng
Published: November 2005

Seismic activity began to slightly increase during the construction but rose sharply upon the completion of the tallest building in the world, the Taipei 101, which stands at 508 m in the Taipei basin, where local seismicity had historically very low. Besides an increase in both seismic energy and the number of micro‐earthquakes, two felt earthquakes astonishingly occurred beneath the completed building. The focal mechanism of the larger felt earthquake and its aftershocks are indicative of an active blind normal fault just beneath the building. Estimations of the vertical loading of the Taipei 101 show that local stress on its foundation increased at least 4.7 bars, making it seem likely that the increased seismicity was a direct product of the loading of the mega‐structure. Further investigations in unison with continuous seismic monitoring must be conducted because the safety of the high‐rise building in the Taipei basin be comprehensively assessed.
Observational evidence of sensitivity of surface climate changes to land types and urbanization
Authors: Lim Young‐Kwon , Cai Ming , Kalnay Eugenia , Zhou Liming
Published: November 2005

Sensitivity of surface climate change to land types is investigated for the Northern Hemisphere by subtracting the reanalysis from the observed surface temperature (OMR). The basis of this approach is that while reanalysis represents the large‐scale climate changes due to greenhouse gases and atmospheric circulation, it is less sensitive to regional surface processes associated with land types. OMR trends derived from two independent reanalyses (ERA40 and NNR) and two observations (CRU and GHCN) show similar dependence upon land types, suggesting the attribution of OMRs to different land types is robust. OMR trends reveal 1) Warming over barren areas is larger than most other land types. 2) Urban areas show large warming second only to barren areas. 3) Croplands with agricultural activity show a larger warming than natural broadleaf forests. The overall assessment indicates surface warming is larger for areas that are barren, anthropogenically developed, or covered with needle‐leaf forests.
Impact of particulate organic matter on the relative humidity dependence of light scattering: A simplified parameterization
Authors: Quinn P. K. , Bates T. S. , Baynard T. , Clarke A. D. , Onasch T. B. , Wang W. , Rood M. J. , Andrews E. , Allan J. , Carrico C. M. , Coffman D. , Worsnop D.
Published: November 2005

Measurements during recent field campaigns downwind of the Indian subcontinent, Asia, and the northeastern United States reveal a substantial decrease in the relative humidity dependence of light scattering, fσsp(RH), with increasing mass fraction of particulate organic matter (POM) for submicrometer aerosol. Using data from INDOEX (INDian Ocean EXperiment), ACE Asia (Aerosol Characterization Experiment – Asia), and ICARTT (International Consortium for Atmospheric Research on Transport and Transformation), we have identified, within measurement limitations, the impact of POM on the fσsp(RH) of accumulation mode sulfate‐POM mixtures. The result is a parameterization that quantifies the POM mass fraction ‐ fσsp(RH) relationship for use in radiative transfer and air quality models either as input or as validation. The parameterization is valid where the aerosol consists of an internally mixed sulfate‐carbonaceous accumulation mode and other externally mixed components (e.g. sea salt, dust) and is applicable on both global and regional scales.
Impact demagnetization of the Martian crust: Primaries versus secondaries
Authors: Artemieva N. , Hood L. , Ivanov B. A.
Published: November 2005

Numerical simulations presented here show that demagnetization of crust near the largest Martian basins by secondary impacts can be comparable to that by direct shock waves outside the transient cavity. The relative input from secondary impacts, which demagnetize only the uppermost layers, depends on the magnetic carrier distribution within the crust. Thus, we discuss properties of likely magnetic remanence carriers and their possible spatial distribution within the crust.
Relative rates of fluvial bedrock incision on Titan and Earth
Authors: Collins Geoffrey C.
Published: November 2005

Observations of likely fluvial channels on the surface of Titan, along with Titan's geologically youthful surface, motivate this study of comparative fluvial erosion rates on Titan and the Earth. The roles of bedload abrasion, suspended load abrasion, plucking, and cavitation are considered. Despite orders of magnitude differences in some of the physical parameters that control fluvial incision on Titan and the Earth, incision rates on Titan are likely to be similar to terrestrial rates, given similar conditions of slope, discharge, and sediment supply.
The k‐filtering technique applied to wave electric and magnetic field measurements from the Cluster satellites
Authors: Tjulin Anders , Pinçon Jean‐Louis , Sahraoui Fouad , André Mats , Cornilleau‐Wehrlin Nicole
Published: November 2005

The k‐filtering technique is a method to characterize stationary fluctuations in space plasmas in terms of the wave energy distribution in the frequency and wave vector space. It has the ability to distinguish between wave modes of the same frequency in the spacecraft frame of reference, but with different wave vectors. This method is based on simultaneous multi‐point measurements of the wave field components, where a filter bank is used to enhance the spatial resolution. We have for the first time combined electric field data from the Electric Field and Wave (EFW) instrument and magnetic field data from the Spatio‐Temporal Analysis of Field Fluctuation (STAFF) instrument on the four Cluster spacecraft in order to determine the wave energy distribution. The k‐filtering technique has previously been performed with only the magnetic field measurements. The reason to include the electric field measurements is that it is important to include as much data as possible in order to get the best possible estimation of the wave energy distribution. Another reason is that it also enables comparisons between the electric and the magnetic part of the wave energy distribution to make it possible to differentiate the observed waves according to their polarization. The k‐filtering method has been extended in order to allow for two measured components of the electric field, and also for the possibility that the electric field measurements from one or more satellites cannot be used for k‐filtering. The technique has been applied on satellite data from the magnetosheath and the foreshock, and from these examples it is clear that k‐filtering using both electric and magnetic field measurements is a good tool for characterizing the waves that are observed in space.
Multi‐scale modeling of the North Pacific Ocean: Assessment and analysis of simulated basin‐scale variability (1996–2003)
Authors: Curchitser Enrique N. , Haidvogel Dale B. , Hermann Albert J. , Dobbins Elizabeth L. , Powell Thomas M. , Kaplan Alexey
Published: November 2005

A primitive equation ocean general circulation model is used to investigate climate impacts in the North Pacific Ocean in the 1996 to 2003 period. The objective is to assess the model ability to reproduce observed modes of variability and study their impact in the northeast Pacific. This work is done within the framework of the U.S. Global Ecosystem (GLOBEC) Northeast Pacific Program studying the links between climate variability and ecosystem dynamics. Three large‐scale events are considered: The 1997/1998 El Niño, the 1999 “regime shift,” and the 2002 cold/fresh subsurface anomalous water mass that was observed in the Gulf of Alaska and off the coast of Oregon. The circulation model is shown to generate the correct seasonal to interannual large‐scale variability and is able to represent the climatic signals of interest in the eastern Pacific. We show that the influence of the 1997/1998 El Niño reached the coastal Gulf of Alaska and induced an increase in the upper ocean heat content along the coast of North America. An analysis of the sea surface temperature for the model years shows agreement between model and data in the representation of the 1999 shift to a cold phase in the eastern and northern North Pacific. Finally, using the model results, we speculate that the origin of the 2002 cold/fresh anomaly in the northeast Pacific was due to enhanced mixing during the preceding winter in the center of the Alaska gyre. Owing to anomalous changes in the density structure of the upper ocean, this water was able to move geostrophically toward the coast and it persisted in the northeast Pacific below the mixed layer the following year.
Optical properties of the particles in the Crimea coastal waters (Black Sea)
Authors: Chami M. , Shybanov E. B. , Churilova T. Y. , Khomenko G. A. , Lee M. E.‐G. , Martynov O. V. , Berseneva G. A. , Korotaev G. K.
Published: November 2005

A field experiment was carried out in summer 2002 on an oceanographic platform near the coast of Crimea, in the Black Sea. For the first time, the spectral volume scattering function (VSF) was measured for a wide range of scattering angles (i.e., from 0.6 to 177.3 degrees) using a recently developed device. Our analysis revealed that the mineral particles are the primary component influencing the scattering and backscattering coefficient in the study area. The good correlation obtained between the backscattering coefficient bbp and the nonalgal particles absorption coefficient showed that the absorption efficiency of the mineral particles is high in the second half of the experiment. The ratio Chla/cp (where Chla is the chlorophyll a concentration and cp is the beam attenuation coefficient) did not correlate with the backscattering ratio and thus could not be used in this experiment as an alternative proxy to estimate the bulk composition of the particles. The spectral variation of bp (the scattering coefficient) and bbp (the backscattering coefficient) was less steep than what can be found in the open ocean waters. That was explained by the influence of the absorption on the scattering process, especially in the blue, as a consequence of the anomalous dispersion. The average backscattering ratio bp varied spectrally within 4%. Nevertheless, a high spectral variability of bp (around 30%) was observed suggesting that the use of a flat spectral variation is not accurate in coastal zones.
Description and climatology of a new general circulation model of the Martian atmosphere
Authors: Hartogh Paul , Medvedev Alexander S. , Kuroda Takeshi , Saito Ryu , Villanueva Geronimo , Feofilov Artem G. , Kutepov Alexander A. , Berger Uwe
Published: November 2005

The paper presents a new grid point global general circulation model (GCM) for the Martian atmosphere with the vertical domain extending from the surface into the lower thermosphere (around 130 km). The model contains the comprehensive physical parameterizations relevant to this altitude range, including a novel CO2 15 μm band radiation scheme for the non‐LTE. The performance of the model is shown in the zonal mean fields simulated for several seasons. The comparison demonstrates a good agreement with the temperature measurements by the Thermal Emission Spectrometer below 40 km and an overall agreement with the results from other Martian GCMs. The model was used to demonstrate that the global meridional transport during solstices is forced primarily by eddies and that the ability of the model to simulate the winter polar warming depends on the ability to resolve the longitudinal disturbances, both topographically and radiatively generated.
Record of Little Ice Age sea surface temperatures at Bermuda using a growth‐dependent calibration of coral Sr/Ca
Authors: Goodkin Nathalie F. , Hughen Konrad A. , Cohen Anne L. , Smith Struan R.
Published: November 2005

Strontium to calcium ratios (Sr/Ca) are reported for a massive brain coral Diploria labyrinthiformis collected from the south shore of Bermuda and are strongly correlated with both sea surface temperature (SST) and mean annual skeletal growth rate. High Sr/Ca ratios correspond with cold SSTs and slow skeletal growth rate and vice versa. We provide a quantitative calibration of Sr/Ca to extension rate and SST along the axis of maximum growth and derive a growth‐dependent Sr/Ca–SST calibration equation to reconstruct western subtropical North Atlantic SSTs for the past 223 years. When the influence of growth rate is excluded from the calibration, Sr/Ca ratios yield SSTs that are too cold during cool anomalies and too warm during warm anomalies. Toward the end of the Little Ice Age (∼1850), SST changes derived using a calibration that is not growth‐dependent are exaggerated by a factor of 2 relative to those from the growth‐corrected model that yields SSTs ∼1.5°C cooler than today. Our results indicate that incorporation of growth rate effects into coral Sr/Ca calibrations may improve the accuracy of SSTs derived from living and fossil corals.
SNP Haplotypes in the Angiotensin I‐Converting Enzyme (ACE) Gene: Analysis of Nigerian Family Data Using Gamete Competition Models
Authors: McKenzie C. A. , Sinsheimer J. S. , Adeyemo A. A. , Cox R. D. , Southam L. , Hugill A. , Bouzekri N. , Lathrop M. , Forrester T. E. , Cooper R. S. , Ward R.
Published: November 2005

Gamete competition models were used to explore the relationships between 13 ACE gene polymorphisms and plasma ACE concentration in a set of Nigerian families. Several markers in the 5′ and 3′ regions of the gene were significantly associated with ACE concentration (P < 10‐4). Multi‐locus genotypes comprising different combinations of markers from the 5′ UTR and the 3′ region of the gene were also analysed; in addition to G2350A, in the 3′ region, two markers from the 5′ UTR (A‐5466C and A‐240T) were found to be associated with ACE concentration. These results are consistent with reports that have suggested the presence of at least two ACE‐linked QTLs, and demonstrate the utility of gamete competition models in the exploratory investigation of the relationship between a quantitative trait and multiple variants in a small genomic region.
Haplotype Effects on Human Survival: Logistic Regression Models Applied to Unphased Genotype Data
Authors: Tan Q. , Christiansen L. , Bathum L. , Zhao J. H. , Vach W. , Vaupel J. W. , Christensen K. , Kruse T. A.
Published: November 2005

Haplotype based linkage disequilibrium (LD) mapping exhibits higher power than the single locus approach because it makes use of the LD information contained in the flanking markers. New statistical methods have been proposed to help to infer haplotype effects on human diseases using multi‐locus genotype data collected from unrelated individuals. In this paper, we introduce a statistical procedure for measuring haplotype effects on human survival using the popular logistic regression model with haplotype based parameterizations. By modeling haplotype frequency as a function of age, our model infers haplotype effects by estimating and testing the slope parameters under different genetic mechanisms (multiplicative, dominant, or recessive). In addition, by estimating the sex‐specific slope parameters, our model allows the detection of sex‐specific haplotype effects or haplotype‐sex interactions. As an example, we apply our model to an empirical dataset on a stress related gene, interleukin‐6, to look for haplotypes that affect individual survival and for haplotype‐sex interactions. We show that our logistic regression based haplotype model can be a helpful tool for researchers interested in the genetics of human aging and longevity.
Analysis of Y‐chromosome Variability and its Comparison with mtDNA Variability Reveals Different Demographic Histories Between Islands in the Azores Archipelago (Portugal)
Authors: Montiel R. , Bettencourt C. , Silva C. , Santos C. , Prata M. J. , Lima M.
Published: November 2005

We determined the Y‐chromosomal composition of the population of the Azores Islands (Portugal), by analyzing 20 binary polymorphisms located in the non‐recombining portion of the Y‐chromosome (NRY), in 185 unrelated individuals from the three groups of islands forming the Archipelago (Eastern, Central and Western). Similar to that described for other Portuguese samples, the most frequent haplogroups were R1(xR1b3f) (55.1%), E(xE3a) (13%) and J (8.6%). Principal components analysis revealed a Western European profile for the Azorean population. No significant differences between Azores and mainland Portugal were observed. However, the haplogroup distribution across the three groups of islands was not similar (P<0.003). The Western group presented differences in the frequencies of haplogroups R1, E(xE3a) and I1b2 (27.3%, 22.7% and 13.6%, respectively) when compared to the other two groups. An assessment of the NRY variability, and its comparison with mitochondrial DNA (mtDNA) variability, was further evidence of the differential composition of males during the settlement of the three groups of islands, contrary to what has been previously deduced for the female settlers using mtDNA data.
Linkage Analysis of Plasma ApoE in Three Ethnic Groups: Multiple Genes with Context‐Dependent Effects
Authors: Klos K. L. E. , Kardia S. L. R. , Hixson J. E. , Turner S. T. , Hanis C. , Boerwinkle E. , Sing C. F.
Published: November 2005

We performed variance component‐based linkage analysis in four samples (two of non‐Hispanic European‐Americans from Rochester, MN; African‐Americans from Jackson, MS; and Mexican‐Americans from Starr County, TX) to identify chromosomal regions containing genes influencing plasma apolipoprotein E (apoE) levels. The APOE gene region on chromosome (chr) 19 was identified with a LOD ≥ 2.00 in both samples from Rochester and the sample from Jackson. Adjustment of apoE levels for differences among means of genotypes defined by the APOE ε2/3/4 alleles reduced evidence of linkage, indicating that the APOE gene was responsible for the majority of the linkage signal. In stratified linkage analyses, there was a LOD of 1.70 in the Starr County sibships with average total cholesterol (TC) above the median level for all sibships in that population. Adjustment for APOE genotype did not remove this LOD score, suggesting a second gene in this region may influence apoE variation. Evidence of linkage (LOD= 3.32) on chr 17 was observed in the Starr County sibships with average TC below the median. Inter‐individual variation in plasma apoE level may be influenced by variations in the structural gene, and at least one other gene whose effects differ among populations and are dependent on the influence of unmeasured genetic and environmental factors indexed by correlated measures of lipid metabolism.
dHPLC Screening of the NSD1 gene Identifies Nine Novel Mutations – Summary of the first 100 Sotos Syndrome Mutations
Authors: Melchior Linea , Schwartz Marianne , Duno Morten
Published: November 2005

Sotos syndrome belongs to the family of overgrowth syndromes and is characterized by large head circumference, craniofacial anomalies, advanced bone age and mental retardation. The syndrome is due to haploinsufficiency of the NSD1 gene, consisting of 23 exons with an open reading frame of 8088bp, which makes mutation screening by direct sequencing quite a laborious and expensive task. We have developed a dHPLC screening protocol for mutation detection in NSD1 and identified 9 novel mutations among 33 patients, thus achieving a mutation detection efficiency comparable to direct sequencing. A real‐time quantitative PCR approach identified two patients with NSD1 deletions. Our mutation screen is compared to other studies and all published mutations and polymorphisms are summarized.
High Resolution T2 Association Tests of Complex Diseases Based on Family Data
Authors: Fan Ruzong , Knapp Michael , Wjst Matthias , Zhao Caixia , Xiong Momiao
Published: November 2005

This paper proposes family based Hotelling's T2 tests for high resolution linkage disequilibrium (LD) mapping or association studies of complex diseases. Assume that genotype data of multiple markers or haplotype blocks are available for a sample of nuclear families, in which some offspring are affected. Paired Hotelling's T2 test statistics are proposed for a high resolution association study using parents as controls for affected offspring, based on two coding methods: haplotype/allele coding and genotype coding. The paired Hotelling's T2 tests take not only the correlation between the haplotype blocks or markers into account, but also take the correlation within each parent‐offspring pair into account. The method extends two sample Hotelling's T2 test statistics for population case control association studies, which are not valid for family data due to correlation of genetic data among family members. The validity of the proposed method is justified by rigorous mathematical and statistical proof under the large sample theory. The non‐centrality parameter approximations of the test statistics are calculated for power and sample size calculations. From power comparison and type I error calculations, it is shown that the test statistic based on haplotype/allele coding is advantageous over the test statistic of genotype coding. Analysis using multiple markers may provide higher power than single marker analysis. If only one marker is utilized the power of the test statistic based on haplotype/allele coding is nearly identical to that of 1‐TDT. Moreover, a permutation procedure is provided for data analysis. The method is applied to data from a German asthma family study. The results based on the paired Hotelling's T2 statistic tests confirm the previous findings. However, the paired Hotelling's T2 tests produce much smaller P‐values than those of the previous study. The permutation tests produce similar results to those of the previous study; moreover, additional marker combinations are shown to be significant by permutation tests. The proposed paired Hotelling's T2 statistic tests are potentially powerful in mapping complex diseases. A SAS Macro, Hotel_fam.sas, has been written to implement the method for data analysis.
Local orientations of fluctuating fluid interfaces
Authors: Mecke Klaus , Dietrich Siegfried
Published: November 2005

Thermal fluctuations cause the local normal vectors of fluid interfaces to deviate from the vertical direction defined by the flat mean interface position. This leads to a nonzero mean value of the corresponding polar tilt angle which renders a characterization of the thermal state of an interface. Based on the concept of an effective interface Hamiltonian we determine the variances of the local interface position and of its lateral derivatives. This leads to the probability distribution functions for the metric of the interface and for the tilt angle which allows us to calculate its mean value and its mean-square deviation. We compare the temperature dependences of these quantities as predicted by the simple capillary-wave model, by an improved phenomenological model, and by the microscopic effective interface Hamiltonian derived from density-functional theory. The mean tilt angle discriminates clearly between these theoretical approaches and emphasizes the importance of the variation of the surface tension at small wavelengths. Also the tilt angle two-point correlation function is determined which renders an additional structural characterization of interfacial fluctuations. Various experimental accesses to measure the local orientational fluctuations are discussed.
ac electroosmosis in rectangular microchannels
Authors: Campisi Michele , Accoto Dino , Dario Paolo
Published: November 2005

Motivated by the growing interest in ac electroosmosis as a reliable no moving parts strategy to control fluid motion in microfluidic devices for biomedical applications, such as lab-on-a-chip, we study transient and steady-state electrokinetic phenomena (electroosmosis and streaming currents) in infinitely extended rectangular charged microchannels. With the aid of Fourier series and Laplace transforms we provide a general formal solution of the problem, which is used to study the time-dependent response to sudden ac applied voltage differences in case of finite electric double layer. The Debye-Hückel approximation has been adopted to allow for an algebraic solution of the Poisson-Boltzmann problem in Fourier space. We obtain the expressions of flow velocity profiles, flow rates, streaming currents, as well as expressions of the complex hydraulic and electrokinetic conductances. We analyze in detail the dependence of the electrokinetic conductance on the extension of linear dimensions relative to the Debye length, with an eye on finite electric double layer effects.
Single particle versus ensemble average: From power-law intermittency of a single quantum dot to quasistretched exponential fluorescence decay of an ensemble
Authors: Tang Jau , Marcus R. A.
Published: November 2005

Light-induced diffusion-controlled electron transfer is proposed as an underlying mechanism for the intermittency (power law and breakdown) of a single quantum dot and ensemble-averaged fluorescence decay. The intensity decay can be approximated to a stretched exponential expression. The physical links to the free energy gap, reorganization energy, electronic coupling, and diffusion correlation times are discussed. A procedure is described for extracting these molecular-based parameters from experiments and is demonstrated with examples using existing data.
Practical rules for orbital-controlled ferromagnetism of 3d impurities in semiconductors
Authors: Zhao Yu-Jun , Mahadevan Priya , Zunger Alex
Published: November 2005

We distill from first-principles spin-polarized total-energy calculations some practical rules for predicting the magnetic state (ferromagnetic/antiferromagnetic/paramagnetic) of substitutional transition-metal impurity with different charge state in various host crystal groups IV, III-V, II-VI, I-III-VI2, and II-IV-V2 semiconductors. The basic mechanism is the stabilization of a ferromagnetic bond between two transition metals if the interacting orbitals are partially-occupied. These rules are then subjected to quantitative tests, which substantiate the mechanism of ferromagnetism in these systems. We discuss cases where current electronic structure calculations agree with these rules, and identify a few cases where conflicts exist. The effect of doping on transition-metal magnetic properties is also covered by these rules by considering the oxidation state changes due to doping. In addition, we systematically apply these rules to ideal substitutional impurities, contrasting our predictions with experiment. Discrepancies may be used to assess the role of various nonidealities such as presence of additional dopants, precipitates, clusters, or interstitial sites.
Infrared spectrum of cyclic ozone: A theoretical investigation
Authors: Qu Z.-W. , Zhu H. , Schinke R.
Published: November 2005

The infrared absorption spectrum of cyclic ozone is calculated by means of a new ab initio potential energy surface, the dipole moment function, and exact quantum mechanical dynamics calculations. Five different isotopomers are considered. The absorption line for excitation of the bending fundamental near 800cm−1 is by far the strongest band; all other bands are more than one order of magnitude less intense. This spectral pattern as well as the isotope shifts for the various isotopomers are important for identifying cyclic ozone. Several possibilities for accessing the ring minimum of cyclic ozone are also discussed on the basis of recent electronic structure calculations.
Photothermal reshaping of prismatic Au nanoparticles in periodic monolayer arrays by femtosecond laser pulses
Authors: Huang Wenyu , Qian Wei , El-Sayed Mostafa A.
Published: November 2005

Prismatic gold nanoparticles in the periodic monolayer arrays prepared with nanosphere lithography technique can be reshaped with femtosecond laser pulses at different powers and wavelengths. As the power density of 400 nm femtosecond laser increases, the prismatic particle tips begin to round and the overall particle shape changes from a prism to a sphere with a tripodal intermediate. The formation of the tip-rounded nanoprisms is probably due to the dewetting properties of gold on quartz surface and the low melting temperature at the tips. The formation of the tripodal nanoparticles is attributed to the inhomogeneous heating and lattice rearrangement of the as-deposited nanoparticles to a metastable state, which is more stable than the prismatic shape but less stable than the spherical shape. With 800 nm femtosecond laser irradiation, only tip-rounded nanoprisms are observed and no spherical nanoparticles are formed at the laser powers used. This is most likely due to the blueshift of the plasmon absorption band for the transformed particles, so that they cannot absorb the required energy to overcome the barrier to make the spherical shape. With 700 nm femtosecond laser irradiation, the tip-rounded and the tripodal nanoparticles are formed and few spherical particles are observed at the higher laser power density. From the results of this work, it is shown that by changing the wavelength and power density of the femtosecond laser, one can control the final shape of the particles formed from the original prismatic nanoparticles.
Influence of noble-gas ion irradiation on alumina barrier of magnetic tunnel junctions
Authors: Sacher M. D. , Sauerwald J. , Schmalhorst J. , Reiss G.
Published: November 2005

The transport properties of Co∕Al2O3∕Co magnetic tunnel junctions with ion-irradiated tunneling barrier are reported. The irradiation by He+ and Ar+ with energies ranging from 15to105eV takes place in situ after oxidation of the 1.4-nm-thick Al layer. For both ion species the area resistance of the junctions increases strongly with ion energy, simultaneously the tunneling magnetoresistance is reduced. But the energy dependence of both properties is different for He+ and Ar+ irradiations. Additionally the bias voltage dependence of the tunneling magnetoresistance is deteriorated with increasing ion energy especially for Ar+ irradiation. These experimental results are discussed with respect to the energy-dependent penetration depth of He+ and Ar+ and their energy loss in the barrier.
Spectroellipsometric approach to determine linear electro-optic coefficient of c-axis-oriented LiNbO3 thin films
Authors: Akazawa Housei , Shimada Masaru
Published: November 2005

We present a simple method to determine the linear electro-optic coefficient of thin films with spectroscopic ellipsometry. This technique allows noncontact and nondestructive measurement of the as-grown state of films without the need to fabricate a waveguide. The principle behind this is that the electro-optic effect is regarded as perturbation to the optical parameters. Comparing differences in tanΨ spectra in terms of applied voltage and wavelength yields a change in the effective wavelength of light propagating through a dielectric medium, which is equivalent to electro-optic-induced phase shift. We demonstrate the feasibility of this procedure to determine the Pockels coefficient (r33) of a preferentially c-axis-oriented LiNbO3 film on a Si(100) substrate. Dispersion of effective r33 values at wavelengths between 0.3 and 0.8μm was obtained.
Hollow cathode theory and experiment. II. A two-dimensional theoretical model of the emitter region
Authors: Mikellides Ioannis G. , Katz Ira , Goebel Dan M. , Polk James E.
Published: November 2005

Despite their long history and wide range of applicability that includes electric propulsion, detailed understanding of the driving physics inside orificed hollow cathodes remains elusive. The theoretical complexity associated with the multicomponent fluid inside the cathode, and the difficulty of accessing empirically this region, have limited our ability to design cathodes that perform better and last longer. A two-dimensional axisymmetric theoretical model of the multispecies fluid inside an orificed hollow cathode is presented. The level of detail attained by the model is allowed by its extended system of governing equations not solved for in the past within the hollow cathode. Such detail is motivated in part by the need to quantify the effect(s) of the plasma on the emitter life, and by the need to build the foundation for future modeling that will assess erosion of the keeper plate. Results from numerical simulations of a 1.2-cm-diam cathode operating at a discharge current of 25A and a gas flow rate of 5SCCM show that approximately 10A of electron current, and 3.45A of ion current return back to the emitter surface. The total emitted electron current is 33.8A and the peak emitter temperature is found to be 1440K. Comparisons with the measurements suggest that anomalous heating of the plasma is possible near the orifice region. The model predicts heavy species temperatures as high as 2034K and peak voltage drops near the emitting surface not exceeding 8V.
Hollow cathode theory and experiment. I. Plasma characterization using fast miniature scanning probes
Authors: Goebel Dan M. , Jameson Kristina K. , Watkins Ron M. , Katz Ira , Mikellides Ioannis G.
Published: November 2005

A detailed study of the spatial variation of plasma density, temperature, and potential in hollow cathodes using miniature fast scanning probes has been undertaken in order to better understand the cathode operation and to provide benchmark data for the modeling of the cathode performance and life described in a companion paper. Profiles are obtained throughout the discharge and in the very high-density orifice region by pneumatically driven Langmuir probes, which are inserted directly into the hollow cathode orifice from either the upstream insert region inside the hollow cathode or from the downstream anode-plasma region. A fast transverse-scanning probe is also used to provide radial profiles of the cathode plume as a function of position from the cathode exit. The probes are extremely small to avoid perturbing the plasma; the ceramic tube insulator is 0.05cm in diameter with a probe tip area of 0.002cm2. A series of current-voltage characteristics are obtained by applying a rapid sawtooth voltage wave form to the probe as it is scanned through the plasma at speeds of up to 2m∕s to produce the profiles with a spatial resolution of about 0.05cm. At discharge currents of 10–25A from the 1.5-cm-diameter hollow cathode, the plasma density inside the cathode is found to exceed 1014cm−3, with the peak density occurring upstream of the orifice. The plasma potentials on axis inside the cathode are found to be in the 10–20V range with electron temperatures of 2–5eV, depending on the discharge current and gas flow rate. A potential discontinuity or double layer of less than 10V is observed in the orifice region, and under certain conditions appears in the bright “plasma ball” in front of the cathode. This structure tends to change location and magnitude with discharge current, gas flow, and orifice size. A potential maximum proposed in the literature to exist in or near the cathode orifice is not observed. Instead, the plasma potential increases from the orifice exit both radially and axially over several centimeters to values of 5–10V above the anode voltage. The potential and temperature profiles inside the cathode are insensitive to anode configuration changes that alter the discharge voltage at a given flow. Application of an axial magnetic-field characteristic of the cathode region found in ring-cusp ion thrusters increases the plasma density in the cathode plume, but does not significantly change the potential or temperature. Measurements of the plasma profiles and the internal cathode parameters for a hollow cathode operating at discharge currents of up to 25A in xenon are shown and discussed.
Action of strong coupling on steplike magnetization and transport properties in phase-separated manganite
Authors: Cao Guixin , Zhang Jincang , Xu Yan , Wang Shipeng , Yu Jian , Cao Shixun , Jing Chao , Shen Xuechu
Published: November 2005

For phase-separated La0.275Pr0.35Ca0.375MnO3 manganite, a steplike charge-ordered antiferromagnetic-ferromagnetic transition was observed by field induction and accompanied by a sudden drop of resistivity. The results can be explained in terms of the spin reorientation in the antiferromagnetic (AFM) phase and simultaneous destruction of orbital ordering by a magnetic field. Combined with specific heat and magnetization measurements, the electronic state density at Fermi energy was greatly enhanced at 5T, which shows the increase of carrier number due to delocalization effect, by analogy with the spin reorientation due to destruction of orbital ordering by magnetic field. The present results prove that the strong coupling among spin, charge, and orbital ordering would be the main cause of existing complex physical behavior at low temperature, which depends sensitively on the spin orientation of adjacent charge-ordered AFM domains and can be controlled by applied field.
Ultimate regime of convection: Robustness to poor thermal reservoirs
Authors: Roche P.-E. , Gauthier F. , Chabaud B. , Hébral B.
Published: November 2005

A transition to Kraichnan ultimate regime of convection has been reported in very high Rayleigh numbers experiments, but not in all of them. These apparently contradictory results can be explained by a recent phenomenological model that accounts for the nonideality of the plate thermal properties [Chillà et al., Phys. Fluids 16, 2452 (2004)]. In this paper, we present a direct test of this model, using a low conductivity plate. We found an unaltered transition, not compatible with the model’s predictions.