bluuebunny/crossref_metadata_2025 huggingface dataset:
A General Synthesis of High‐Quality Inorganic Nanocrystals via a Two‐Phase Method
Authors: Zhao Nana , Nie Wei , Mao Jun , Yang Muquan , Wang Dapeng , Lin Yuhan , Fan Yandi , Zhao Ziliang , Wei Hua , Ji Xiangling
Published: October 2010

A two‐phase method is exploited to prepare many kinds of nearly monodisperse, highly crystalline, size‐ and shape‐controlled, surface‐property‐tunable inorganic nanocrystals, such as metal, semiconducting, magnetic, dielectric, and rare earth nanocrystals. The reaction of the two‐phase system happens at the interface between the oil (nonpolar) and water (polar) phases and the interface is an exclusive site for both nucleation and growth. Interestingly, many solvent pairs with a clear interface can be applied to synthesize inorganic nanocrystals successfully. Generally, as‐prepared nanocrystals with organic ligands are soluble in nonpolar solvents. Furthermore, exchange of ligands can also be realized readily and the final nanocrystals can be soluble in polar solvents. This two‐phase method is a simple, reproducible, and general route and is becoming as powerful an approach as other solution‐based synthetic approaches to high‐quality inorganic nanocrystals.
From Hair to Cornea: Toward the Therapeutic Use of Hair Follicle-Derived Stem Cells in the Treatment of Limbal Stem Cell Deficiency
Authors: Meyer-Blazejewska Ewa Anna , Call Mindy K. , Yamanaka Osamu , Liu Hongshan , Schlötzer-Schrehardt Ursula , Kruse Friedrich E. , Kao Winston W.
Published: October 2010

Limbal stem cell deficiency (LSCD) leads to severe ocular surface abnormalities that can result in the loss of vision. The most successful therapy currently being used is transplantation of limbal epithelial cell sheets cultivated from a limbal biopsy obtained from the patient's healthy, contralateral eye or cadaveric tissue. In this study, we investigated the therapeutic potential of murine vibrissae hair follicle bulge-derived stem cells (HFSCs) as an autologous stem cell (SC) source for ocular surface reconstruction in patients bilaterally affected by LSCD. This study is an expansion of our previously published work showing transdifferentiation of HFSCs into cells of a corneal epithelial phenotype in an in vitro system. In this study, we used a transgenic mouse model, K12rtTA/rtTA/tetO-cre/ROSAmTmG, which allows for HFSCs to change color, from red to green, once differentiation to corneal epithelial cells occurs and Krt12, the corneal epithelial-specific differentiation marker, is expressed. HFSCs were isolated from transgenic mice, amplified by clonal expansion on a 3T3 feeder layer, and transplanted on a fibrin carrier to the eye of LSCD wild-type mice (n = 31). The HFSC transplant was able to reconstruct the ocular surface in 80% of the transplanted animals; differentiating into cells with a corneal epithelial phenotype, expressing Krt12, and repopulating the corneal SC pool while suppressing vascularization and conjunctival ingrowth. These data highlight the therapeutic properties of using HFSC to treat LSCD in a mouse model while demonstrating a strong translational potential and points to the niche as a key factor for determining stem cell differentiation.
Curcuminoids rescue long‐term potentiation impaired by amyloid peptide in rat hippocampal slices
Authors: Ahmed Touqeer , Gilani Anwarul‐Hassan , Hosseinmardi Narges , Semnanian Saeed , Enam Syed Ather , Fathollahi Yaghoub
Published: October 2010

Curcuminoids are vital constituent of turmeric, with therapeutic potential in the treatment of Alzheimer's disease. Electrically, stimulus train‐elicited plastic changes in hippocampal CA1 excitability were used as an experimental paradigm to study the effects of curcuminoid mixture and individual components on functional failure induced by Aβ peptide in vitro. Electrical stimulation was applied on Schaffer collaterals, and population spikes (PS) were recorded from stratum pyramidale. To induce long‐term potentiation (LTP) of PS, primed burst stimulation (PBs) was used. Aβ peptide inhibited PS LTP induction. Sinking PS LTP due to Aβ peptide was rescued when curcuminoid mixture was applied before PBs only at lower dose (0.1 μM) resulting in PS potentiation to 127.42% ± 1.83% at 5 min and 123.98% ± 1.06% at 60‐min post‐PBs. Similarly, when bisdemethoxycurcumin was applied, PS LTP was induced and lasted only at a single dose (0.1 μM). Demethoxycurcumin was effective at a middle dose (1 μM), so that the PS amplitude was changed to 140.15% ± 2.68% and 129.82% ± 0.44% at 5 and 60 min, respectively. PS LTP was effectively induced in the presence of curcumin at middle and high doses (1 and 30 μM) with resultant PS LTP to 155.68% ± 1.23% and 127.72% ± 1.23%, respectively, at 60‐min post‐PBs. These results showed that curcuminoids can restore susceptibility for plastic changes in CA1 excitability that is injured by exposure to Aβ peptide and rescue sinking PS LTP in Aβ‐peptide‐exposed hippocampal CA1 neurons. Synapse, 2011. © 2010 Wiley‐Liss, Inc.
Das Präventionsprogramm ,,Lenzgesund‘‘: Strukturbildung in einem benachteiligten Quartier in Hamburg
Authors: Süß Waldemar
Published: October 2010

Einleitung

Das Gesundheitsamt Hamburg-Eimsbüttel hat in der Lenzsiedlung ein Präventionsprogramm („Lenzgesund – vernetzte frühe Hilfen ..... “) auf den Weg gebracht, das mit dem „Runden Tisch Lenzgesund” umgesetzt wurde und wird. Für diesen Prozess der Entwicklung und Umsetzung eines systematischen Konzeptes hat das Institut für Medizin-Soziologie die Begleitforschung übernommen. Das Projekt unterstützt mit unterschiedlichen Methoden die Umsetzung, insbesondere was die formative Evaluation und die Qualitätssicherung betrifft. Zur Anwendung kommen sekundärstatistische Analysen (GBE) und Primärerhebungen bei Einzelintervention aber auch bezogen auf die Gesamtprogrammebene.
Geological structure of the oil-and-gas plays and oil-and-gas potential of the southern Siberian Platform
Authors: Samsonov V.V. , Larichev A.I. , Chekanov V.I. , Solov’ev V.V.
Published: October 2010

The paper discusses modern views of the structure of the main producing plays in the southern Siberian Platform: Riphean, Vendian, and Lower Cambrian. The major zones of oil and gas accumulation have been distinguished. Forecast resources have undergone differentiated expert evaluation, and methods for their development have been recommended.
Use of surgical telescopes by senior dental students: A survey
Authors: Hagge Mark S.
Published: October 2010

This survey examined the use of surgical telescopes (STs) in a large senior dental student class. The percentage of students who purchased STs, factors that influenced those purchases, frequency/patterns of use, and purchase satisfaction were investigated. The survey return rate was 85.3% (128 of 150). Among the respondents, 86% had purchased STs and 14% had not. The most frequent motive for ST purchase was advice received from others (43%); ergonomic reasons were cited by 21% of users. Fixed‐lens designs were selected more frequently (70%) than flip‐down systems (30%). Nearly all ST purchases were made during the first year of dental school (95%), and low‐power magnification (× 2–2.5) was chosen by 88% of purchasers. STs were used more often for operative dentistry, fixed prosthodontics, endodontics, and pediatric dentistry than for practice in other disciplines. ST users expressed a high level of satisfaction with their purchases (84%). The most common reason given for not purchasing STs was being able to see well enough without them (9 of 18; 50%).
Squamous cell carcinoma of the thyroid gland: primary or secondary disease?
Authors: Syed M I , Stewart M , Syed S , Dahill S , Adams C , McLellan D R , Clark L J
Published: October 2010

Objective:

To review the aetiopathogenesis, clinical characteristics, immunohistochemical profile, prognosis and treatment options for primary thyroid squamous cell carcinoma, and to compare it with squamous cell carcinoma metastatic to the thyroid, thus providing the reader with a framework for differentiating primary and secondary disease.

Method:

Review of English language literature from the past 25 years.

Search strategy:

A search of the Medline, Embase and Cochrane databases (April 1984 to April 2009) was undertaken to enable a comprehensive review.

Results:

After applying strict criteria for the diagnosis of primary thyroid squamous cell carcinoma, 28 articles were identified reporting 84 cases. When reviewing secondary thyroid squamous cell carcinoma, we only analysed cases of squamous cell carcinoma metastatic to the thyroid gland, and found 28 articles reporting 78 cases.

Conclusion:

It is possible to differentiate between primary and secondary thyroid squamous cell carcinoma, on the basis of combined evidence from clinical examination and endoscopic, pathological and radiological evaluation. Such differentiation is important, as the prognosis for primary squamous cell carcinoma is uniformly poor irrespective of treatment, and the most suitable option may be supportive therapy. Treatment for secondary squamous cell carcinoma of the thyroid varies with the site and extent of spread of the primary tumour.
The different trajectories of antipsychotic response: antipsychotics versus placebo
Authors: Marques T. R. , Arenovich T. , Agid O. , Sajeev G. , Muthén B. , Chen L. , Kinon B. J. , Kapur S.
Published: October 2010

Background

It is generally accepted that antipsychotics are more effective than placebo. However, it remains unclear whether antipsychotics induce a pattern or trajectory of response that is distinct from placebo. We used a data-driven technique, called growth mixture modelling (GMM), to identify the different patterns of response observed in antipsychotic trials and to determine whether drug-treated and placebo-treated subjects show similar or distinct patterns of response.

Method

We examined data on 420 patients with schizophrenia treated for 6 weeks in two double-blind placebo-controlled trials using haloperidol and olanzapine. We used GMM to identify the optimal number of response trajectories; to compare the trajectories in drug-treated versus placebo-treated patients; and to determine whether the trajectories for the different dimensions (positive versus negative symptoms) were identical or different.

Results

Positive symptoms were found to respond along four distinct trajectories, with the two most common trajectories (‘Partial responder’ and ‘Responder’) accounting for 70% of the patients and seen proportionally in both drug- and placebo-treated. The most striking drug–placebo difference was in the ‘Dramatic responders’, seen only among the drug-treated. The response of negative symptoms was more modest and did not show such distinct trajectories.

Conclusions

Trajectory models of response, rather than the simple responder/non-responder dichotomy, provide a better statistical account of how antipsychotics work. The ‘Dramatic responders’ (those showing >70% response) were seen only among the drug-treated and make a significant contribution to the overall drug–placebo difference. Identifying and studying this subset may provide specific insight into antipsychotic action.
The Estimation of Nonparametric Functions in a Hilbert Space
Authors: Bergstrom A. R.
Published: October 2010

This paper is concerned with the estimation of a nonlinear regression function which is not assumed to belong to a prespecified parametric family of functions. An orthogonal series estimator is proposed, and Hilbert space methods are used in the derivation of its properties and the proof of several convergence theorems. One of the main objectives of the paper is to provide the theoretical basis for a practical stopping rule which can be used for determining the number of Fourier coefficients to be estimated from a given sample.
The Estimation of Higher-Order Continuous Time Autoregressive Models
Authors: Harvey A. C. , Stock James H.
Published: October 2010

A method is presented for computing maximum likelihood, or Gaussian, estimators of the structural parameters in a continuous time system of higherorder stochastic differential equations. It is argued that it is computationally efficient in the standard case of exact observations made at equally spaced intervals. Furthermore it can be applied in situations where the observations are at unequally spaced intervals, some observations are missing and/or the endogenous variables are subject to measurement error. The method is based on a state space representation and the use of the Kalman–Bucy filter. It is shown how the Kalman-Bucy filter can be modified to deal with flows as well as stocks.
Minimax Estimators for the Location Vectors of Spherically Symmetric Densities
Authors: Judge George , Miyazaki Shigetaka , Yancey Thomas
Published: October 2010

The estimation of K (K ≥ 3) location parameters is considered under quadratic loss when the coordinates of the best invariant estimators are spherically symmetrically distributed. Under these stochastic mechanisms traditional Stein estimators are evaluated for finite samples and shown to have a risk performance superior to some conventional rules.
The Estimation of Open Higher-Order Continuous Time Dynamic Models with Mixed Stock and Flow Data
Authors: Bergstrom A. R.
Published: October 2010

This article extends recent work on the Gaussian or quasi-maximum likelihood estimation of the parameters of a closed higher-order continuous time dynamic model by introducing exogenous variables into the model The method presented yields exact maximum likelihood estimates when the innovations are Gaussian and the exogenous variables are polynomials in time of degree not exceeding two, and it can be expected to yield very good estimates under more general conditions. It is applicable, in principle, to a system of any order with mixed stock and iow data. The precise formulas for its implementation are derived, in this article, for a second-order system in which both the endog-enous and exogenous variables are a mixture of stock and flow variables.
Econometric Methodology at the Cowles Commission: Rise and Maturity
Authors: Malinvaud E.
Published: October 2010

Considering the contribution of the Cowles research institute to the development of econometrics, one has little choice in this address and must mainly focus attention on one major achievement, namely, the building of the simultaneous equation methodology. One does not need to demonstrate the indisputable fact that this methodology was conceived and elaborated at the Cowles Commission in the forties. Neither does one need to insist on the long standing significance of this achievement nor on its central place in any education or reflection concerning statistical inference about economic phenomena. More interesting is the question of how research at Cowles during the first 15 years of its existence led to this result and how further econometric research here during the last 30 years relates to the simultaneous equation achievement. Also relevant is the following question: how does the message that was sent out by the Cowles people to the world in 1950 stand today? Should it be replaced by another different one? Or should it simply be somewhat amended and supplemented?

To do full justice to the research work and achievements of the many econometricians that were associated with Cowles through the years would require a much longer paper than the present one. But one must at least try also to summarize here those main concerns that stood outside the simultaneous equation methodology.
On Rereading Haavelmo: A Retrospective View of Econometric Modeling
Authors: Spanos Aris
Published: October 2010

The main aim of the paper is to reevaluate the methodological contributions of Tinbergen and Haavelmo in the context of the current discussions on econometric modeling and propose a reformulation of the Haavelmo methodology. The paper argues that the textbook methodology constitutes a less flexible version of Tinbergen's approach and apart from the probabilistic language, it has little in common with the methodology in Haavelmo's 1944 monograph, commonly acknowledged as having founded modern econometrics. The methodology in this monograph includes several important elements which have either been discarded or never fully integrated within the textbook approach. A re-synthesis of these elements gives rise to an alternative methodological framework. This framework can be used to meet most of the objections to the textbook methodology and provides a framework in the context of which the recent methodological controversies can be evaluated.
Predictors in Dynamic Nonlinear Models: Large-Sample Behavior
Authors: Brown Bryan W. , Mariano Roberto S.
Published: October 2010

The large-sample behavior of one-period-ahead and multiperiod-ahead predictors for a dynamic nonlinear simultaneous system is examined in this paper. Conditional on final values of the endogenous variables, the asymptotic moments of the deterministic, closed-form, Monte Carlo stochastic, and several variations of the residual-based stochastic predictor are analyzed. For one-period-ahead prediction, the results closely parallel our previous findings for static nonlinear systems. For multiperiod-ahead prediction similar results hold, except that the effective number of sample-period residuals available for use with the residual-based predictor is T/m, where T denotes sample size. In an attempt to avoid the problems associated with sample splitting, the complete enumeration predictor is proposed which is a multiperiod-ahead generalization of the one-period-ahead residual-based predictor. A bootstrap predictor is also introduced which is similar to the multiperiod-ahead Monte Carlo except disturbance proxies are drawn from the empirical distribution of the residuals. The bootstrap predictor is found to be asymptotically inefficient relative to both the complete enumeration and Monte Carlo predictors.
The Bias of Bootstrapped Versus Conventional Standard Errors in the General Linear and SUR Models
Authors: Atkinson Scott E. , Wilson Paul W.
Published: October 2010

When estimating the seemingly unrelated regression (SUR) model in small samples, the bootstrap feasible generalized least-squares (FGLS) covariance estimator has been widely advocated as less biased than the conventional FGLS covariance estimator obtained by evaluating the asymptotic covariance matrix. Assuming multivariate normal errors and an unbiased estimator of the error covariance, Eaton proves that the conventional estimator is biased downward for a general SUR model. Ignoring termsO(T–2) for this model, we prove that the bootstrap estimator is also biased downward. However, from these results, the relative magnitude of these two biases is indeterminant in general. By ignoring termsO(T–2) for Zellner's two-equation, orthogonal regressor model with bivariate normal errors, we show that the bias of both estimators is downward and that the bootstrap estimator exhibits a smaller bias than the conventional estimator. Monte Carlo simulation results indicate that, in general, neither estimator uniformly dominates the other.
Stochastic Expansions and Asymptotic Approximations
Authors: Magdalinos Michael A.
Published: October 2010

Under general conditions the distribution function of the first few terms in a stochastic expansion of an econometric estimator or test statistic provides an asymptotic approximation to the distribution function of the original estimator or test statistic with an error of order less than that of the limiting normal or chi-square approximation. This can be used to establish the validity of several refined asymptotic methods, including the comparison of Nagar-type moments and the use of formal Edgeworth or Edgeworth-type approximations.
The Cowles Commission, the Brookings Project, and the Econometric Services Industry: Successes and Possible New Directions: A Personal View
Authors: McCarthy Michael D.
Published: October 2010

This paper presents an overview of the Cowles Commission effort in the area of econometric theory and a critical review of the Brookings Project, but flaws are noted in both efforts. The Brookings part reflects a view of the project as seen by one of the younger members of the coordinating team; it is a view shared to some extent by other members. The paper deals with the research work stimulated by both projects and contains a brief but frank discussion of the emergence of a commercial econometric services industry. Finally, promising areas for future research are noted.
Simultaneous Density Estimation of Several Income Distributions
Authors: Marron J.S. , Schmitz H.-P.
Published: October 2010

The size distributions of net income in Great Britain changed systematically in the 1970s. This can be shown by visual comparison of nonparametric density estimates. Typical bandwidth selection methods, such as least squares and biased cross-validation, tend to hinder comparison, because of too much variability across curves. Hence, a method for finding an appropriate pooled bandwidth is developed. It is seen that this method is much more reliable than single curve cross-validation.
Convergence to Stochastic Integrals for Dependent Heterogeneous Processes
Authors: Hansen Bruce E.
Published: October 2010

This paper provides conditions to establish the weak convergence of stochastic integrals. The theorems are proved under the assumption that the innovations are strong mixing with uniformly bounded 2-h moments. Several applications of the results are given, relevant for the theories of estimation with I(1) processes, I(2) processes, processes with nonstationary variances, near-integrated processes, and continuous time approximations.
Some Exact Formulae for Autoregressive Moving Average Processes
Authors: Zinde-Walsh Victoria
Published: October 2010

This paper demonstrates that for a finite stationary autoregressive moving average process the inverse of the covariance matrix differs from the matrix of the covariances of the inverse process by a matrix of low rank. The formula for the exact inverse of the covariance matrix of the scalar or multivariate process is provided. We obtain approximations based on this formula and evaluate some of the approximate results in the existing literature. Applications to computational algorithms and to the distributions of two-step estimators are discussed. In addition the paper contains the formula for the determinant of the covariance matrix which is useful in exact maximum likelihood estimation; it also lists the expressions for the autocovariances of scalar autoregressive moving average processes.
Laws of Large Numbers for Dependent Non-Identically Distributed Random Variables
Authors: Andrews Donald W.K.
Published: October 2010

This paper provides L1 and weak laws of large numbers for uniformly integrable L1-mixingales. The L1-mixingale condition is a condition of asymptotic weak temporal dependence that is weaker than most conditions considered in the literature. Processes covered by the laws of large numbers include martingale difference, ø(·), ρ(·), and α(·) mixing, autoregressive moving average, infinite-order moving average, near epoch dependent, L1-near epoch dependent, and mixingale sequences and triangular arrays. The random variables need not possess more than one finite moment and the L1-mixingale numbers need not decay to zero at any particular rate. The proof of the results is remarkably simple and completely self-contained.
When cues collide: children's sensitivity to letter- and meaning-patterns in spelling words in English
Authors: DEACON S. H. , LEBLANC D. , SABOURIN C.
Published: October 2010

In many learning situations, we need to determine to which cues to attend, particularly in cases when these cues conflict. These conflicts appear often in English orthography. In two experiments, we asked children to spell two-syllable words that varied on two dimensions: morphological and orthographic structure. In one set of these words, the two sources of information conflicted. Results of Experiment 1 suggest that seven- to nine-year-old children are sensitive to both orthographic and morphological dimensions of words, and that this dual sensitivity sometimes leads to correct spelling and sometimes to incorrect spelling. Results of Experiment 2 suggest that orthographic information dominates young (six-year-old) children's spelling, at least in a case when there is a strong orthographic regularity. Taken together, these experiments suggest that children are sensitive to the multiple dimensions of regularity in English orthography and that this sensitivity can lead to mistakes.
Interactions between lexical and phonological development: cross-linguistic and contextual considerations – a commentary on Stoel-Gammon's ‘Relationships between lexical and phonological development in young children’
Authors: DEMUTH KATHERINE
Published: October 2010

Stoel-Gammon (this issue) provides a welcome addition to the phonological acquisition literature, bringing together insights from long-standing and more recent research to address the relationship between the developing phonological system and the developing lexicon. A growing literature on children's early use of words across languages and phonological contexts provides additional insight into the nature of the interactions between phonological and lexical development, suggesting that learners' knowledge and connection of the two may develop much earlier than often thought. This commentary highlights some of these exciting results from recent cross-linguistic research on development between the ages of 1 and 3.
Relationships between lexical and phonological development: a look at bilingual children – a commentary on Stoel-Gammon's ‘Relationships between lexical and phonological development in young children’*
Authors: KEHOE MARGARET
Published: October 2010

Stoel-Gammon (this issue) highlights the close and symbiotic association that exists between the lexical and phonological domains in early linguistic development. Her comprehensive review considers two bodies of literature: (1) child-centred studies; and (2) studies based on adult psycholinguistic research. Within the child-centred studies, both prelinguistic and early meaningful speech is examined. Stoel-Gammon organizes her review of child-centred studies around a series of postulates that capture the associations between lexical and phonological development and here she focuses primarily on normally developing children acquiring American English. My intention is not to question these postulates, which are based on established research findings, but to extend them beyond the limits of her review. In my commentary, I would like to explore the application of some of the stated postulates of the early meaningful speech period in children acquiring two or more languages. In so doing, I add a cross-linguistic dimension to the discussion; a dimension that Stoel-Gammon would like to see pursued in future research on this topic. I also expand our understanding of lexical–phonological relationships by considering the potential for interaction in multiple lexical–phonological relationships.
The evolution and distribution of phage ST160 withinSalmonella entericaserotype Typhimurium
Authors: PRICE-CARTER M. , ROY-CHOWDHURY P. , POPE C. E. , PAINE S. , DE LISLE G. W. , COLLINS D. M. , NICOL C. , CARTER P. E.
Published: October 2010

Salmonellosis is an internationally important disease of mammals and birds. Unique epidemics in New Zealand in the recent past include twoSalmonellaserovars:Salmonella entericasubsp.entericaserovar Typhimurium definitive type (DT) 160 (S. Typhimurium DT160) andS. Brandenburg. Although not a major threat internationally, in New ZealandS. Typhimurium DT160 has been the most common serovar isolated from humans, and continues to cause significant losses in wildlife. We have identified DNA differences between the first New Zealand isolate ofS. Typhimurium DT160 and the genome-sequenced strain,S. Typhimurium LT2. All the differences could be accounted for in one cryptic phage ST64B, and one novel P22-like phage, ST160. The majority of the ST160 genome is almost identical to phage SE1 but has two regions not found in SE1 which are identical to the P22-like phage ST64T, suggesting that ST160 evolved from SE1 via two recombination events with ST64T. All of the New Zealand isolates of DT160 were identical indicating the clonal spread of this particularSalmonella. Some overseas isolates ofS. Typhimurium DT160 differed from the New Zealand strain and contained SE1 phage rather than ST160. ST160 was also identified in New Zealand isolates ofS. Typhimurium DT74 andS. Typhimurium RDNC-April06 and inS. Typhimurium DT160 isolates from the USA. The emergence ofS. Typhimurium DT160 as a significant pathogen in New Zealand is postulated to have occurred due to the sensitivity of theSalmonellastrains to the ST160 phage whenS. Typhimurium DT160 first arrived.
THE LOGIC OF LEGITIMACY: Bootstrapping Paradoxes of Constitutional Democracy
Authors: Zurn Christopher F.
Published: October 2010

Many have claimed that legitimate constitutional democracy is either conceptually or practically impossible, given infinite regress paradoxes deriving from the requirement of simultaneously democratic and constitutional origins for legitimate government. This paper first critically investigates prominent conceptual and practical bootstrapping objections advanced by Barnett and Michelman. It then argues that the real conceptual root of such bootstrapping objections is not any specific substantive account of legitimacy makers, such as consent or democratic endorsement, but a particular conception of the logic of normative standards—the determinate threshold conception—that the critic attributes to the putatively undermined account of legitimacy. The paper further claims that when we abandon threshold conceptions of the logic of legitimacy in favor of regulative-ideal conceptions, then the objections, from bootstrapping paradoxes to the very idea of constitutional democracy, disappear. It concludes with considerations in favor of adopting a more demanding conception of the regulative ideal of constitutional democracy, advanced by Habermas, focusing on potentials for developmental learning.
Simulating STEM Imaging of Nanoparticles in Micrometers-Thick Substrates
Authors: Demers H. , Poirier-Demers N. , Drouin D. , de Jonge N.
Published: October 2010

Scanning transmission electron microscope (STEM) images of three-dimensional (3D) samples were simulated. The samples consisted of a micrometer(s)-thick substrate and gold nanoparticles at various vertical positions. The atomic number (Z) contrast as obtained via the annular dark-field detector was generated. The simulations were carried out using the Monte Carlo method in the CASINO software (freeware). The software was adapted to include the STEM imaging modality, including the noise characteristics of the electron source, the conical shape of the beam, and 3D scanning. Simulated STEM images of nanoparticles on a carbon substrate revealed the influence of the electron dose on the visibility of the nanoparticles. The 3D datasets obtained by simulating focal series showed the effect of beam broadening on the spatial resolution and on the signal-to-noise ratio. Monte Carlo simulations of STEM imaging of nanoparticles on a thick water layer were compared with experimental data by programming the exact sample geometry. The simulated image corresponded to the experimental image, and the signal-to-noise levels were similar. The Monte Carlo simulation strategy described here can be used to calculate STEM images of objects of an arbitrary geometry and amorphous sample composition. This information can then be used, for example, to optimize the microscope settings for imaging sessions where a low electron dose is crucial for the design of equipment, or for the analysis of the composition of a certain specimen.
Empirical ocean color algorithms for estimating particulate organic carbon in the Southern Ocean
Authors: Allison David B. , Stramski Dariusz , Mitchell B. Greg
Published: October 2010

We have examined empirical algorithms for estimating surface concentration of particulate organic carbon (POC) from remotely sensed ocean color in the Southern Ocean using field data of POC, spectral remote‐sensing reflectance, Rrs(λ), and the inherent optical properties (IOPs) of seawater collected during a number of cruises. Several algorithm formulations have been considered, including direct relationships between POC and the blue‐to‐green band ratios of reflectance and a single‐wavelength two‐step algorithm that consists of relationships linking reflectance to the backscattering coefficient and POC to the particulate backscattering coefficient at 555 nm. The best error statistics among the algorithms tested were obtained for the power function fit POC (in mg m−3) = 189.29 [Rrs(443)/Rrs(555)]−0.87. This band ratio algorithm is based on 85 pairs of field data and shows a small mean bias of about 3%, the normalized root mean square error of 27%, and the determination coefficient of 0.93. These error statistics as well as the analysis of matchup comparisons of satellite‐derived POC and in situ POC determinations support the prospect for reasonably good performance of this algorithm in the Southern Ocean. The two‐step empirical algorithm operating at 555 nm shows inferior error statistics of the regression fits and matchup comparisons compared with the band ratio algorithm. The analysis of our data set also indicates that a general trend of variation in the blue‐to‐green reflectance band ratio over the examined range of POC values is driven primarily by the green‐to‐blue ratio of particulate absorption coefficient.
Summertime land‐atmosphere interactions in response to anomalous springtime snow cover in northern Eurasia
Authors: Matsumura Shinji , Yamazaki Koji , Tokioka Tatsushi
Published: October 2010

An atmospheric general circulation model (AGCM) is used to investigate the effects of springtime high‐latitude snow cover on the summertime climate system in the form of land‐atmosphere interactions in northern Eurasia. We performed light and heavy snow runs in which the initial snow mass in northern Eurasia was varied. Significant differences in model response between the light and heavy snow runs are evident in terms of not only land surface parameters but also summertime northern atmospheric circulation. Changes in the initial snow cover have a strong effect on the simulated surface air temperature. In western Siberia, the albedo of the snow cover makes a strong contribution to the difference in surface heating between the runs, because snow mass anomalies are still present over western Siberia in June. In eastern Siberia (the Lena Basin), where the snow disappears in June in both runs, the snow‐hydrological effect is prominent throughout summer. The increased soil moisture in the heavy snow run causes increased evaporation, resulting in turn in surface cooling. The initial soil moisture content is dry in eastern Siberia and wet in western Siberia, resulting in contrasting responses between the two regions. In the light snow run, the subpolar jet is strengthened and maintained along the Arctic coast in early summer, and wave activity propagates eastward over northern Eurasia. Changes in the atmospheric circulation generate an east‐west dipole structure of precipitation anomalies over northern Eurasia. These results suggest that variations in the springtime Eurasian snow mass result in changes in the summertime northern atmospheric circulation and hydrological cycle via land‐atmosphere interactions.
Diagnosis of multilayer clouds using photon path length distributions
Authors: Li Siwei , Min Qilong
Published: October 2010

Photon path length distribution is sensitive to 3‐D cloud structures. A detection method for multilayer clouds has been developed, by utilizing the information of photon path length distribution. The photon path length method estimates photon path length information from the low level, single‐layer cloud structure that can be accurately observed by a millimeter‐wave cloud radar (MMCR) combined with a micropulse lidar (MPL). As multiple scattering within the cloud layers and between layers would substantially enhance the photon path length, the multilayer clouds can be diagnosed by evaluating the estimated photon path information against observed photon path length information from a co‐located rotating shadowband spectrometer (RSS). The measurements of MMCR‐MPL and RSS at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site have been processed for the year 2000. Cases studies illustrate the consistency between MMCR‐MPL detection and the photon path length method under most conditions. However, the photon path length method detected some multilayer clouds that were classified by the MMCR‐MPL as single‐layer clouds. From 1 year statistics at the ARM SGP site, about 27.7% of single‐layer clouds detected by the MMCR‐MPL with solar zenith angle less than 70° and optical depth greater than 10 could be multilayer clouds. It suggests that a substantial portion of single‐layer clouds detected by the MMCR‐MPL could also be influenced by some “missed” clouds or by the 3‐D effects of clouds.
Spatial changes of inter‐plate coupling inferred from sequences of small repeating earthquakes in Japan
Authors: Igarashi Toshihiro
Published: October 2010

We extract sequences of small repeating earthquakes to clarify inter‐plate coupling of subducting plates over a large area of the Japanese Islands. As a result, many sequences are detected at the Philippine Sea plate subducting from the Ryukyu trench and Pacific plate subducting from the Kuril‐Japan trench. The average slip‐rates and standard deviations estimated from the sequences show substantial spatial changes of inter‐plate coupling. The large deviations of slip‐rates correspond to the occurrence of episodic slips such as after‐slips following large earthquakes. Constant slip‐rates approaching the relative plate motion indicate weak coupling areas. Slip deficits and sparse distributions of repeating groups suggest locked areas. In the Nankai trough, deep low‐frequency earthquakes in the transition zone and burst‐type repeating sequences within plates have not been located in the downdip direction of groups with slow slip‐rates. This suggests that the space‐time characteristics of inter‐plate coupling affected these seismic events.
Parametric decay of linearly polarized shear Alfvén waves in oblique propagation: One and two‐dimensional hybrid simulations
Authors: Matteini Lorenzo , Landi Simone , Del Zanna Luca , Velli Marco , Hellinger Petr
Published: October 2010

The parametric instability of a monochromatic shear Alfvén wave in oblique propagation with respect the ambient magnetic field is investigated in a kinetic regime, performing one‐dimensional (1‐D) and two‐dimensional (2‐D) hybrid simulations. The parallel component of the mother wave is found to be subject to a parametric decay which excites an ion‐acoustic wave along the magnetic field and a backward propagating daughter shear Alfvén wave, as in the instability for a purely parallel mother wave. At the same time, the acoustic wave generation supports the acceleration of a velocity beam in the ion distribution function, due to the non‐linear trapping of protons. Moreover, the instability leads to the generation of broad band oblique spectra of coupled Alfvénic and compressive modes with variable perpendicular wavevectors, and, as a consequence, the magnetic field after saturation is characterized by a strong transverse modulation.
On the fractional solubility of copper in marine aerosols: Toxicity of aeolian copper revisited
Authors: Sholkovitz Edward R. , Sedwick Peter N. , Church Thomas M.
Published: October 2010

Paytan et al. (2009) argue that the atmospheric deposition of aerosols lead to copper concentrations that are potentially toxic to marine phytoplankton in a large area of tropical and subtropical North Atlantic Ocean. A key assumption in their model is that all marine aerosols (mineral dust and anthropogenic particles) have a high (40%) fractional solubility of copper. Our data show that the fractional solubility of copper for Saharan dust over the Sargasso Sea and Bermuda is significantly lower (1–7%). In contrast, anthropogenic aerosols with non‐Saharan sources have significantly higher values (10–100%). Hence, the potential Cu toxicity in the tropical and subtropical North Atlantic should be re‐estimated, given the low fractional solubility of Cu in the Saharan dust that dominates aerosol deposition to this region.
A simple MHD model for the formation of multiple dipolarization fronts
Authors: Guzdar P. N. , Hassam A. B. , Swisdak M. , Sitnov M. I.
Published: October 2010

A simplified MHD model is proposed that explains characteristic features of dipolarization fronts observed by the five‐probe THEMIS mission, and in particular the recurrent or multiple fronts, as structures arising from the nonlinear evolution of the interchange instability of the initial reconnection ejecta in the terrestrial magnetotail. Modeling the effects of the magnetic field curvature and plasma braking by an effective gravity and imposing an initial seed perturbation consistent with the observed dawn‐dusk scale of fronts is shown to reproduce the observed variations of the north‐south magnetic field, bulk flow plasma velocity, number density and pressure.
Observations of interstellar neon in the helium focusing cone
Authors: Drews Christian , Berger Lars , Wimmer‐Schweingruber Robert F. , Galvin Antoinette B. , Klecker Berndt , Möbius Eberhard
Published: October 2010

Extended pickup ion distributions in the heliosphere have been found to originate either from interstellar neutral gas or from the so‐called inner source. Because of the motion of the Sun through the interstellar medium, interstellar neutral gas flows through the inner heliosphere and for some of the species is focused on the downwind side by the gravitation of the Sun. This gravitational focusing cone, which is absent for inner source ions, has been identified for He with UV backscattering and pickup ion observations and is used to diagnose the interstellar parameters. Using the large geometric factor of the Plasma and Suprathermal Ion Composition instrument on the Solar Terrestrial Relations Observatory mission, we have studied heavy pickup ions in the mass‐per‐charge range 12–20 during 2007 and 2008. We have clearly identified C+, N+, O+, the H2O+ group, and Ne+ among the heavy pickup ions. Out of these, Ne+ shows clear enhancements during two consecutive focusing cone passages, as evidenced by concurrent He+ enhancements during these periods, whereas all the other species are evenly distributed. This is the first observation of the interstellar focusing cone for Ne, whose survival probability as neutrals is only slightly lower than that of He and substantially higher than for other elements.
Effects of sulfate coatings on the ice nucleation properties of a biological ice nucleus and several types of minerals
Authors: Chernoff Donna I. , Bertram Allan K.
Published: October 2010

An optical microscope coupled to a flow cell was used to study the ice nucleation properties of uncoated and coated mineral dust and SNOMAX (a proxy for biological ice nucleators made from cells of Pseudomonas syringae) at temperatures ranging from 234 to 247 K. We define the onset conditions as the relative humidity (RH) and temperature at which the first ice nucleation event was observed. The results show that H2SO4 coatings modified the ice nucleation properties of all the minerals studied. For kaolinite and illite, the acid coatings increased the RH over ice (RHi) required for ice nucleation by ∼30% RHi; for montmorillonite and quartz, the acid coatings increased the RHi by ∼20% RHi. NH4HSO4 coatings also influenced the ice nucleation properties of kaolinite particles. In addition, our results indicate that SNOMAX is a reasonably good ice nucleus, having onset values between 110 to 120% RHi. In contrast to the mineral studies, sulfuric acid coatings did not hinder the ice nucleating ability of SNOMAX particles. Combined, our results support the idea that anthropogenic emissions of SO2 and NH3 may influence the ice‐nucleating properties of mineral dust particles. From our laboratory data, we also determined contact angles (θ) between the heterogeneous nuclei and ice embryos according to classical nucleation theory to parameterize the laboratory data for inclusion in atmospheric models. The data show that for uncoated ice nuclei the contact angles are small (below ∼20°), but for mineral particles coated with sulfuric acid, the contact angles are larger (above ∼60°).
Evaluation of the model representation of the evolution of convective systems using satellite observations of outgoing longwave radiation
Authors: Pearson K. J. , Hogan R. J. , Allan R. P. , Lister G. M. S. , Holloway C. E.
Published: October 2010

We introduce a technique for assessing the diurnal development of convective storm systems based on outgoing longwave radiation fields. Using the size distribution of the storms measured from a series of images, we generate an array in the length scale‐time domain based on the standard score statistic. It demonstrates succinctly the size evolution of storms as well as the dissipation kinematics. It also provides evidence related to the temperature evolution of the cloud tops. We apply this approach to a test case comparing observations made by the Geostationary Earth Radiation Budget instrument to output from the Met Office Unified Model run at two resolutions. The 12 km resolution model produces peak convective activity on all length scales significantly earlier in the day than shown by the observations and no evidence for storms growing in size. The 4 km resolution model shows realistic timing and growth evolution, although the dissipation mechanism still differs from the observed data.
Use of electrical imaging and distributed temperature sensing methods to characterize surface water–groundwater exchange regulating uranium transport at the Hanford 300 Area, Washington
Authors: Slater Lee D. , Ntarlagiannis Dimitrios , Day‐Lewis Frederick D. , Mwakanyamale Kisa , Versteeg Roelof J. , Ward Andy , Strickland Christopher , Johnson Carole D. , Lane John W.
Published: October 2010

We explored the use of continuous waterborne electrical imaging (CWEI), in conjunction with fiber‐optic distributed temperature sensor (FO‐DTS) monitoring, to improve the conceptual model for uranium transport within the Columbia River corridor at the Hanford 300 Area, Washington. We first inverted resistivity and induced polarization CWEI data sets for distributions of electrical resistivity and polarizability, from which the spatial complexity of the primary hydrogeologic units was reconstructed. Variations in the depth to the interface between the overlying coarse‐grained, high‐permeability Hanford Formation and the underlying finer‐grained, less permeable Ringold Formation, an important contact that limits vertical migration of contaminants, were resolved along ∼3 km of the river corridor centered on the 300 Area. Polarizability images were translated into lithologic images using established relationships between polarizability and surface area normalized to pore volume (Spor). The FO‐DTS data recorded along 1.5 km of cable with a 1 m spatial resolution and 5 min sampling interval revealed subreaches showing (1) temperature anomalies (relatively warm in winter and cool in summer) and (2) a strong correlation between temperature and river stage (negative in winter and positive in summer), both indicative of reaches of enhanced surface water–groundwater exchange. The FO‐DTS data sets confirm the hydrologic significance of the variability identified in the CWEI and reveal a pattern of highly focused exchange, concentrated at springs where the Hanford Formation is thickest. Our findings illustrate how the combination of CWEI and FO‐DTS technologies can characterize surface water–groundwater exchange in a complex, coupled river‐aquifer system.