bluuebunny/crossref_metadata_2025 huggingface dataset:
CP/MAS spectroscopy in the determination of the tautomeric forms of gossypol, its Schiff bases and hydrazones in the solid state
Authors: Przybylski Piotr , Schilf Wojciech , Kamienski Bohdan , Brzezinski Bogumil , Bartl Franz
Published: March 2008

New Schiff bases and new hydrazones were synthesized and studied by 13C and 15N CP/MAS spectroscopy and by 1H1H COSY, 1H13C HMBC, 1H13C HSQC, 1H15N HMQC and 1H15N HSQC correlations. The CP/MAS investigation of gossypol has demonstrated that in the solid state it exists exclusively in the aldehyde‐aldehyde tautomeric form. In contrast, CP/MAS studies of hydrazones and Schiff bases reveal that these compounds occur in the solid state in the N‐imine–N‐imine and enamine–enamine tautomeric forms, respectively. It is shown that the 13C resonances of C‐6, C‐7 and C‐11 carbon atoms are suitable for distinguishing between the tautomeric forms of aza‐derivatives of gossypol in the solid state. Furthermore, we have proved that the 15N CP/MAS spectra can be used to identify these tautomeric forms. Copyright © 2008 John Wiley & Sons, Ltd.
Application of some physical organic chemistry models to the study of oil spills residues in Patagonian soils
Authors: Nudelman N. Sbarbati , Ríos Stella M. , Katusich Ofelia
Published: March 2008

The present study focuses on the application of some physical organic chemistry (POC) models for a better understanding of the interactions between oil spills and soil. By studying the sorption behavior of pure compounds, it was possible to examine the application of the multilayer model to the prediction of crude oil isotherms. The difference between the predicted and experimental oil isotherms was only 13%, which indicates the reliability of the model. The distribution coefficients, Kd, of soil samples containing oil residuals of different ages, were also determined using methanol as a co‐solvent. Desorption experiments showed that they are a function of the polarity of the liquid phases; the Kds, calculated by applying a model derived from the solvophobic theory, increase with increasing age. On the other hand, the natural attenuation of oil spills was studied by using GC and 1H NMR techniques. Signals for four types of aliphatic and for the aromatic protons were clearly assigned; signals for alcohol (OH) and carboxylic (COOH) protons were also observed; compounds exhibiting these polar groups are usually not detected in the GC–FID conventional analysis. The principal component analysis (PCA) of Kd, and the parameters determined by GC and NMR, showed that the first and second PC, accounted for more than 95 and 81% of variance, for NMR and GC parameters, respectively. The detailed results suggest that the 1H NMR data would be more useful than GCs to evaluate the environmental transformations that oil spills undergo in Patagonian soils. Nevertheless, direct extrapolation of the present results to other environments is not possible because the changes depend strongly on the original chemical composition of the crude oil and the variable exposure conditions along the time. Copyright © 2008 John Wiley & Sons, Ltd.
A mathematically related singularity and the maximum size of protein domains
Authors: Szilágyi András
Published: March 2008

In a paper titled “A topologically related singularity suggests a maximum preferred size for protein domains” (Zbilut et al., Proteins 2007;66:621–629), Zbilut et al. claim to have found a singularity in certain geometrical properties of protein structures, and suggest that this singularity may limit the maximum size of protein domains. They find further support for the singularity in their analysis of G‐factors calculated by the PROCHECK program. Here, we show that the claimed singularity is a mathematical artifact with no physical meaning, and we reanalyze the G‐factors to show that Zbilut et al.'s results are due to a single outlier in the data. Thus, the existence of an actual singularity in the topological properties of proteins is not supported by the findings of Zbilut et al. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Characterization of electronic structure and physicochemical properties of antiparasitic nifurtimox analogues: A theoretical study
Authors: Soriano‐Correa Catalina , Raya A. , Esquivel Rodolfo O.
Published: March 2008

American trypanosomiasis, also known as Chagas' disease, is caused by Trypanosoma cruzi (T. cruzi). It is well known that trypanosomes, and particularly T. cruzi, are highly sensitive towards oxidative stress, i.e., to compounds than are able to produce free radicals. Generally, nifurtimox (NFX) and benznidazol are most effective in the acute phase of the disease; therefore, nitroheterocycles constitute good models to design other nitrocompounds with specific biological characteristics. Thus, we have performed an ab initio study at the Hartree‐Fock and Density Functional Theory levels of theory of several NFX analogues recently synthesized, to characterize them by obtaining their electronic, structural, and physicochemical properties, which might be linked to the observed antichagasic activity. The antitrypanosomal activity scale previously reported for the NFX analogues studied in this work is in good agreement with our theoretical results, from which we can conclude that the activity seems to be related to the reactivity along with the acidity observed for the most active molecules. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Effects of methods and basis set on ab initio calculations of electronic transport through hydrogenated Pt nanocontacts
Authors: García Y. , San‐fabián E. , Louis E. , Vergés J. A.
Published: March 2008

The effects of varying methods and basis set on ab initio calculations of electronic transport through hydrogenated Pt nanocontacts have been investigated. The nanocontact atomic arrangement was simulated by means of two pyramids facing each other along the (001) direction, and containing either 5 or 14 atoms each. A hydrogen molecule was placed between the two pyramid apexes, transversal to the nanocontact axis. The reliability of various methods‐basis set combinations has been checked by comparing with experimental data for the equilibrium distance and the vibrational frequency of PtH molecule. The study was carried out using a large set of methods includingthe most classic in the field of Quantum Chemistry (HF), density functional methods (HFLYP, BLYP, PW91PW91, TPSS) as well as hybrids (B3LYP). The most important outcome of this work is a call of attention to those using Quantum Chemistry methods to calculate the conductance through nanosystems, remarking on the need of an appropriate choice of the tools being used in a particular case. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Binary encounter model for the electron impact K‐shell ionization of atoms
Authors: Patoary M. A. R. , Uddin M. Alfaz , Haque A. K. F. , Shahjahan M. , Basak A. K. , Saha B. C.
Published: March 2008

The electron impact K‐shell ionization (EIKSI) cross sections on 18 atomic targets, with the atomic numbers 2 ≤ Z ≤ 92, are calculated using a modified version of the binary encounter approximation (BEA) model. The modified BEA (MBEA), which incorporates both ionic and relativistic corrections and is simpler in application than other existing models, is found to be immensely successful in describing the EIKSI data up to the incident energy of 1 GeV. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Quantum mechanical model for Maya Blue
Authors: Fuentes María E. , Peña Brisa , Contreras César , Montero Ana L. , Chianelli Russell , Alvarado Manuel , Olivas Ramón , Rodríguez Luz M. , Camacho Héctor , Montero‐Cabrera Luis A.
Published: March 2008

This work is about Maya Blue (MB), a pigment developed by Mesoamerican civilizations between the 5th and 16th centuries from an aluminosilicate mineral (palygorskite) and an organic dye (indigo). Two different supramolecular quantum‐mechanical models afford explanations for the unusual stability of MB based on the oxidation of the indigo molecule during the heating process and its interaction with palygorskite. A model considering indigo derivatives attached to several aluminates shows the principal features of the experimental visible spectrum of MB within the TD‐DFT methodology. Another model of an indigo oxidized species confined within an inorganic supramolecular cavity system, that involves about 170 atoms, was calculated after a large configuration interaction of single excited determinants within the NDOL approximation (Montero‐Cabrera et al., J Chem Phys, 2007, 127, 145102). It allows a correct reproduction and interpretation of the corresponding spectrum. This second methodology provides the most satisfactory results, being able to manage very big molecular systems at a QM level. Structural explanation for the unusual stability of MB is also provided. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
2D and 3D‐QSAR studies on antiproliferative thiazolidine analogs
Authors: Liao Si Yan , Qian Li , Chen Jin Can , Lu Hai Liang , Zheng Kang Cheng
Published: March 2008

Two‐dimensional (2D) and three‐dimensional (3D) quantitative structure–activity relationships (QSARs) of 22 thiazolidine analogs with antiproliferative activity expressed as pIC50, which is defined as the negative value of the logarithm of necessary molar concentration of these compounds to cause 50% growth inhibition against melanoma cell lines WM‐164, have been studied by using a combined method of the DFT, MM2 and statistics for 2D, as well as the comparative molecular field analysis (CoMFA) method for 3D. The established 2D‐QSAR model in training set comprised of random 18 compounds shows not only significant statistical quality, but also predictive ability, with the square of adjusted correlation coefficient (R = 0.832) and the square of the cross‐validation coefficient (q2 = 0.803). The same model was further applied to predict pIC50 values of the four compounds in the test set, and the resulting R reaching 0.784, further confirms that this 2D‐QSAR model has high predictive ability. The 3D‐QSAR model also shows good correlative and predictive capabilities in terms of R2 (0.956) and q2 (0.615) obtained from CoMFA model. Further, the robustness of the CoMFA model was verified by bootstrapping analysis (100 runs) with R (0.979) and SDbs (0.056). It is very interesting to find that the results from 2D‐ and 3D‐QSAR analyses accord with each other, and they all show that the steric interaction plays a crucial role in determining the cytotoxicities of the compounds, and that selecting a moderate‐size or appropriate‐hydrophobicity substituent R as well as increasing the negative charges of C4 on phenyl ring at the same time are advantageous to improving the cytotoxicity. Such results can offer some useful theoretical references for directing the molecular design and understanding the action mechanism of this kind of compound with antiproliferative activity. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Highly accurate differential deposition for X‐ray reflective optics
Authors: Handa Soichiro , Mimura Hidekazu , Yumoto Hirokatsu , Kimura Takashi , Matsuyama Satoshi , Sano Yasuhisa , Yamauchi Kazuto
Published: March 2008

We have developed a highly accurate differential deposition system for the fabrication of X‐ray optical devices. Using this system, thin films having a thickness distribution gradually changing along the longitudinal direction on a substrate surface could be produced with sub‐nanometer accuracy. The surface flatness of the deposited films was confirmed by atomic force microscopy observation, and the surface was sufficiently smooth to prevent X‐ray scattering on the mirror surface. A demonstration of differential deposition was performed and a Pt thin film having the desired thickness profile was successfully deposited on a 100 mm long substrate. Copyright © 2008 John Wiley & Sons, Ltd.
The structure of the water–propane interface investigated by x‐ray reflectivity measurements
Authors: Paulus Michael , Gutt Christian , Tolan Metin
Published: March 2008

We present an x‐ray reflectivity study of the water–propane interface. The vertical structure of the interface is analyzed and the adsorption of thin layers of propane on the water surface is observed. An increase of layer thickness with rising pressure is found. The electron density of the thin films is identical with the corresponding value of bulk liquid propane. From the adsorption isotherm we determine the Hamaker constant of the system, which shows a considerably higher value compared to calculations based on the Lifshitz theory. The surface tension of the molecularly thin layer is reduced in comparison to the bulk value. The measured surface roughness is in good agreement with a modified model based on capillary wave fluctuations of the water‐propane–gas interfaces. Copyright © 2008 John Wiley & Sons, Ltd.
Survival models for cost data: The forgotten additive approach
Authors: Pagano Eva , Petrinco Michele , Desideri Alessandro , Bigi Riccardo , Merletti Franco , Gregori Dario
Published: March 2008

The usage of the Aalen additive approach is proposed to model cost data. Using a Monte Carlo simulation, in a wide set of scenarios, we showed that the Aalen model is performing well and can be a reasonable alternative to the standard Gamma regression models. In addition, with reference to the COSTAMI trial data, we highlighted the ability of the Aalen model to offer additional information about the relationships between costs and specific covariates, as compared with standard regression techniques. Copyright © 2008 John Wiley & Sons, Ltd.
How conservative is Fisher's exact test? A quantitative evaluation of the two‐sample comparative binomial trial
Authors: Crans Gerald G. , Shuster Jonathan J.
Published: March 2008

The debate as to which statistical methodology is most appropriate for the analysis of the two‐sample comparative binomial trial has persisted for decades. Practitioners who favor the conditional methods of Fisher, Fisher's exact test (FET), claim that only experimental outcomes containing the same amount of information should be considered when performing analyses. Hence, the total number of successes should be fixed at its observed level in hypothetical repetitions of the experiment. Using conditional methods in clinical settings can pose interpretation difficulties, since results are derived using conditional sample spaces rather than the set of all possible outcomes. Perhaps more importantly from a clinical trial design perspective, this test can be too conservative, resulting in greater resource requirements and more subjects exposed to an experimental treatment. The actual significance level attained by FET (the size of the test) has not been reported in the statistical literature. Berger (J. R. Statist. Soc. D (The Statistician) 2001; 50:79–85) proposed assessing the conservativeness of conditional methods using p‐value confidence intervals. In this paper we develop a numerical algorithm that calculates the size of FET for sample sizes, n, up to 125 per group at the two‐sided significance level, α=0.05. Additionally, this numerical method is used to define new significance levels α*=α+ε, where ε is a small positive number, for each n, such that the size of the test is as close as possible to the pre‐specified α (0.05 for the current work) without exceeding it. Lastly, a sample size and power calculation example are presented, which demonstrates the statistical advantages of implementing the adjustment to FET (using α* instead of α) in the two‐sample comparative binomial trial. Copyright © 2008 John Wiley & Sons, Ltd.
Prevention of Anastomotic Stricture with a Purse‐string Suture Technique on the Gastric Side During Esophageal Carcinoma Operations: Retrospective Study of 463 Consecutive Cases
Authors: Zhang Chong , Yao Min‐hua , Jin Tao , Sun Li , Hu Jian , Zha Yu‐xin
Published: March 2008

Objective

The objective of this study was to investigate the effect of a gastric side purse‐string technique on anastomotic strictures during esophageal carcinoma operations.

Methods

From 1996 to 2005, esophageal carcinoma operations were performed on 1128 consecutive patients. Among them, 463 underwent esophagogastric anastomosis with purse‐string sutures on the gastric side (purse group) and the other 665 did not (nonpurse group). Anastomotic strictures, reflux, and leakage were analyzed and compared between the two groups after the operations.

Results

Complete follow‐up was conducted on all 1128 patients within 6 months after the operation. In contrast to the nonpurse group with a postoperative anastomotic stricture rate of 5.4% (36/665), the purse group demonstrated a significantly lower rate (0.2%, 1/463). The occurrence rates of anastomotic leakage in the nonpurse and purse groups were 0.9% (6/665) and 0.4% (2/463), respectively. Of the 17 cases of gastroesophageal reflux, 15 (15/665, 1.8%) were found in the nonpurse group and 2 (2/463, 1.1%) in the purse group.

Conclusions

Thus, a purse‐string suture technique on the gastric side might be an effective method for preventing the occurrence of anastomotic strictures after esophageal resection.
The consequences of extended newborn screening programmes: Do we know who needs treatment?
Authors: Wilcken B.
Published: March 2008

The development of an evidence base for newborn screening is especially difficult because of the rarity of disorders now detectable. One consequence of expanded newborn screening is that physicians are being called upon to manage asymptomatic babies with persistent biochemical disturbances that indicate likely enzyme deficiencies. Some of these may be very mild. There is not always agreement as to who should be treated. Particular problems are seen with disorders that were previously thought very rare but are now found frequently by newborn screening. Some of these disorders appear benign or nearly so, and in the present state of knowledge should clearly not be included in routine newborn screening panels.
Obsessive–Compulsive Disorder: Influence of Age at Onset on Comorbidity Patterns
Authors: de Mathis Maria Alice , do Rosario Maria Conceição , Diniz Juliana Belo , Torres Albina Rodrigues , Shavitt Roseli Gedanki , Ferrão Ygor Arzeno , Fossaluza Victor , de Bragança Pereira Carlos Alberto , Miguel Eurípedes Constantino
Published: March 2008

Purpose.

This study investigates the influence of age at onset of OCS on psychiatric comorbidities, and tries to establish a cut-off point for age at onset.

Methods.

Three hundred and thirty OCD patients were consecutively recruited and interviewed using the following structured interviews: Yale-Brown Obsessive Compulsive Scale; Yale Global Tic Severity Scale and the Structured Clinical Interview for DSM-IV. Data were analyzed with regression and cluster analysis.

Results.

Lower age at onset was associated with a higher probability of having comorbidity with tic, anxiety, somatoform, eating and impulse–control disorders. Longer illness duration was associated with lower chance of having tics. Female gender was associated with anxiety, eating and impulse–control disorders. Tic disorders were associated with anxiety disorders and attention-deficit/hyperactivity disorder. No cut-off age at onset was found to clearly divide the sample in homogeneous subgroups. However, cluster analyses revealed that differences started to emerge at the age of 10 and were more pronounced at the age of 17, suggesting that these were the best cut-off points on this sample.

Conclusions.

Age at onset is associated with specific comorbidity patterns in OCD patients. More prominent differences are obtained when analyzing age at onset as an absolute value.
How do in vitro reconstituted actin‐based motility assays provide insight into in vivo behavior?
Authors: Bugyi Beáta , Le Clainche Christophe , Romet-Lemonne Guillaume , Carlier Marie-France
Published: March 2008

Recent live cell image analysis of actin dynamics in lamellipodia of motile cells has shown that regulated treadmilling, which supports actin‐based propulsion of functionalized particles in biomimetic reconstituted motility assays, is also responsible for lamellipodia extension. In both cases, filaments are created by branching with Arp2/3 complex only at the membrane or particle surface, grow transiently and are capped; ADF/cofilin enhances the treadmilling but does not sever filaments in the body of the meshwork. Differences between the cellular and biomimetic systems suggest that additional regulatory mechanisms take place in lamellipodia.
MeCP2 preferentially binds to methylated linker DNA in the absence of the terminal tail of histone H3 and independently of histone acetylation
Authors: Ishibashi Toyotaka , Thambirajah Anita A. , Ausió Juan
Published: March 2008

Methyl CpG binding protein 2 (MeCP2) is a basic protein that contains a DNA methyl binding domain. The mechanism by which the highly positive charge of MeCP2 and its ability to bind methylated DNA contribute to the specificity of its binding to chromatin has long remained elusive. In this paper, we show that MeCP2 binds to nucleosomes in a very similar way to linker histones both in vitro and in vivo. However, its binding specificity strongly depends on DNA methylation. We also observed that as with linker histones, this binding is independent of the core histone H3 N‐terminal tail and is not affected by histone acetylation.
LOCAL RADIAL BASIS FUNCTION APPROXIMATION ON THE SPHERE
Authors: HESSE KERSTIN , LE GIA Q. T.
Published: March 2008

In this paper we derive local error estimates for radial basis function interpolation on the unit sphere$\mathbb {S}^2\subset \mathbb {R}^3$. More precisely, we consider radial basis function interpolation based on data on a (global or local) point set$X\subset \mathbb {S}^2$for functions in the Sobolev space$H^s(\mathbb {S}^2)$with norm$\|\cdot \|_s$, wheres>1. The zonal positive definite continuous kernel ϕ, which defines the radial basis function, is chosen such that its native space can be identified with$H^s(\mathbb {S}^2)$. Under these assumptions we derive a local estimate for the uniform error on a spherical capS(z;r): the radial basis function interpolant ΛXfof$f\in H^s(\mathbb {S}^2)$satisfies$\sup _{\mathbf {x}\in S(\mathbf {z};r)} |f(\mathbf {x})-\Lambda _X f(\mathbf {x})| \leq c h^{(s-1)/2} \|f\|_{s}$, whereh=hX,S(z;r)is the local mesh norm of the point setXwith respect to the spherical capS(z;r). Our proof is intrinsic to the sphere, and makes use of the Videnskii inequality. A numerical test illustrates the theoretical result.
RIGIDITY OF GRAPH PRODUCTS OF ABELIAN GROUPS
Authors: GUTIERREZ MAURICIO , PIGGOTT ADAM
Published: March 2008

We show that if G is a group and G has a graph-product decomposition with finitely generated abelian vertex groups, then G has two canonical decompositions as a graph product of groups: a unique decomposition in which each vertex group is a directly indecomposable cyclic group, and a unique decomposition in which each vertex group is a finitely generated abelian group and the graph satisfies the T0 property. Our results build on results by Droms, Laurence and Radcliffe.
Erratum to ‘Semi-hyperbolic fibered rational maps and rational semigroups’ (Ergodic Theory and Dynamical Systems 26 (2006), 893–922)
Authors: SUMI HIROKI
Published: March 2008

We give a correction to the assumption of Theorems 1.12 and 2.6 in the paper [H. Sumi. Semi-hyperbolic fibered rational maps and rational semigroups. Ergod. Th. & Dynam. Sys.26 (2006), 893–922].
HISTORIOGRAPHY AND ENLIGHTENMENT: A VIEW OF THEIR HISTORY
Authors: POCOCK J. G. A.
Published: March 2008

This essay is written on the following premises and argues for them. “Enlightenment” is a word or signifier, and not a single or unifiable phenomenon which it consistently signifies. There is no single or unifiable phenomenon describable as “the Enlightenment,” but it is the definite article rather than the noun which is to be avoided. In studying the intellectual history of the late seventeenth century and the eighteenth, we encounter a variety of statements made, and assumptions proposed, to which the term “Enlightenment” may usefully be applied, but the meanings of the term shift as we apply it. The things are connected, but not continuous; they cannot be reduced to a single narrative; and we find ourselves using the word “Enlightenment” in a family of ways and talking about a family of phenomena, resembling and related to one another in a variety of ways that permit of various generalizations about them. We are not, however, committed to a single root meaning of the word “Enlightenment,” and we do not need to reduce the phenomena of which we treat to a single process or entity to be termed “the” Enlightenment. It is a reification that we wish to avoid, but the structure of our language is such that this is difficult, and we will find ourselves talking of “the French” or “the Scottish,” “the Newtonian” or the “the Arminian” Enlightenments, and hoping that by employing qualifying adjectives we may constantly remind ourselves that the keyword “Enlightenment” is ours to use and should not master us.
Biofuels from Microalgae
Authors: Li Yanqun , Horsman Mark , Wu Nan , Lan Christopher Q. , Dubois‐Calero Nathalie
Published: March 2008

Microalgae are a diverse group of prokaryotic and eukaryotic photosynthetic microorganisms that grow rapidly due to their simple structure. They can potentially be employed for the production of biofuels in an economically effective and environmentally sustainable manner. Microalgae have been investigated for the production of a number of different biofuels including biodiesel, bio‐oil, bio‐syngas, and bio‐hydrogen. The production of these biofuels can be coupled with flue gas CO2 mitigation, wastewater treatment, and the production of high‐value chemicals. Microalgal farming can also be carried out with seawater using marine microalgal species as the producers. Developments in microalgal cultivation and downstream processing (e.g., harvesting, drying, and thermochemical processing) are expected to further enhance the cost‐effectiveness of the biofuel from microalgae strategy.
Long‐term temperature trends in the ionosphere above Millstone Hill
Authors: Holt J. M. , Zhang S. R.
Published: March 2008

Increasing concentrations of greenhouse gases are expected on theoretical grounds to lead to a cooling of the upper atmosphere. Due to the close thermal coupling of the neutral and ionized components of the upper atmosphere the effects of this cooling are also expected to be seen in the ionospheric ion temperature. Long‐term satellite observations of neutral density show a trend consistent with the expected cooling. Temperature data from the Millstone Hill incoherent scatter radar (46.2°N, 288.5°E) from 1978 to 2007 have been analyzed to provide a direct estimate of the temperature trend above the radar. The long‐term trend in the directly measured ion temperature Ti at 375 km is found to be −4.7 K/year with a 95% confidence interval of −3.6 to −5.8 K. The estimated trend in the neutral temperature Tn is −5.0 K/year. These are significantly larger than predicted by theory.
Testing five of the simplest upper mantle anisotropic velocity parameterizations using teleseismic S and SKS data from the Billings, Montana PASSCAL array
Authors: Yuan Huaiyu , Dueker Ken , Schutt Derek L.
Published: March 2008

Five of the simplest parameterizations of upper mantle anisotropy are tested and ranked for a data set collected on a dense temporary PASSCAL seismic array located 100‐km NE of Yellowstone. These hexagonal symmetry anisotropy models possess either one or two layers with either flat or dipping fast velocity axis (FVA). Recordings from fifteen high quality direct‐S and SKS arrivals are stacked to provide accurate waveform and error estimates. Source normalization is accomplished using the cross‐convolution technique. A direct Monte Carlo Neighborhood Algorithm is used to map the posteriori model probability density (PPD) volume. Using the F test, we find that models with purely flat FVA can be rejected at >97% probability. Our best model (P5) is a two layer dipping FVA parameterization, albeit the two layer model with one flat and one dipping FVA can only be rejected at 80% probability. The best model has a lower layer with a N65°E FVA strike and a −12° dip (down to the southwest), and an upper layer with a N20°W FVA strike and a −47° FVA dip (down to the southeast). The bottom asthenospheric layer FVA strikes parallel to North America's absolute plate motion direction and dips opposite to what passive plate shear of the asthenosphere would predict. The upper lithospheric layer is consistent with LPO accretion associated with north directed drift of the North American plate during the Mesozoic. Comparison between the SKS‐and direct S‐wave data sets shows that the direct S waves improve resolution of the double layer anisotropic model parameters.
Coarse mode optical information retrievable using ultraviolet to short‐wave infrared Sun photometry: Application to United Arab Emirates Unified Aerosol Experiment data
Authors: O'Neill N. T. , Eck T. F. , Reid J. S. , Smirnov A. , Pancrati O.
Published: March 2008

The United Arab Emirates Unified Aerosol experiment provided a unique opportunity for testing aerosol retrieval algorithms in conditions where the optical influence of coarse mode particles was significant. Comparisons between Aerosol Robotic Network (AERONET) Sun photometry retrievals of a previously reported spectral deconvolution algorithm (SDA) and surface‐based microphysical and optical measurements showed levels of correlation suggestive of moderate vertical homogeneity for (extensive) measures of fine and coarse mode aerosol particles and stronger vertical homogeneity for indicators of (intensive) aerosol type. An extension of the SDA into the short‐wave infrared (SDA+) was developed in order to exploit the enhanced coarse mode information available in new AERONET instruments which include a 1.64 μm channel. Comparisons between values of coarse mode Angstrom exponent (αc (1.64 μm)) retrieved from SDA+ and effective (coarse mode) radius derived from AERONET inversions showed moderate but significant correlations. Correlations between coarse mode effective radius derived from αc (1.64 μm) and surface‐based volume mean diameter estimates underscored the physical significance of the spectral retrievals and suggested moderate vertical homogeneity in terms of coarse mode particle size.
Understanding the Stable Isotope Composition of Biosphere‐Atmosphere CO2 Exchange
Authors: McDowell Nate , Baldocchi Dennis , Barbour Margaret , Bickford Chris , Cuntz Matthias , Hanson Dave , Knohl Alexander , Powers Heath , Rahn Thomas , Randerson Jim , Riley William J. , Still Chris , Tu Kevin , Walcroft Adrian
Published: March 2008

Stable isotopes of atmospheric carbon dioxide (CO2) contain a wealth of information regarding biosphere‐atmosphere interactions. The carbon isotope ratio of CO2 (δ13C) reflects the terrestrial carbon cycle including processes of photosynthesis, respiration, and decomposition. The oxygen isotope ratio (δ18O) reflects terrestrial carbon and water coupling due to CO2‐H2O oxygen exchange. Isotopic CO2 measurements, in combination with ecosystem‐isotopic exchange models, allow for the quantification of patterns and mechanisms regulating terrestrial carbon and water cycles, as well as for hypothesis development, data interpretation, and forecasting. Isotopic measurements and models have evolved significantly over the past two decades, resulting in organizations that promote model‐measurement networks, e.g., the U.S. National Science Foundation's Biosphere‐Atmosphere Stable Isotope Network, the European Stable Isotopes in Biosphere‐Atmosphere Exchange Network, and the U.S. National Environmental Observatory Network.
Earth Scientists and Public Policy: Have We Failed New Orleans?
Authors: Dixon Timothy H. , Dokka Roy K.
Published: March 2008

Earth scientists rarely influence public policy or urban planning. In defiance of geologic reality, cities are established on or expanded into floodplains, wetlands, earthquake faults, and active volcanoes. One exception to our lack of influence is that shortly after a major natural disaster, there is a brief window of heightened public awareness that may lead to sensible regulation or relocation of infrastructure. After the 1933 Long Beach earthquake, for example, California building codes were improved to reduce earthquake hazard. After Mississippi River flooding in 1993, several U.S. cities designated parts of their low‐lying flood‐plain as green space.
The First Training Workshop on Permafrost Research Methods: IMPETUS 2007: OSL‐APECS‐PYRN Training Workshop; St. Petersburg, Russia, 29 November to 2 December 2007
Authors: Lantuit H. , Kassens H. , Johansson M. , Timokhov L. , Haltigin T. , Baeseman J. , Volkmann‐Lark K.
Published: March 2008

Fifty young researchers from 14 countries met in St. Petersburg, Russia, to learn about the latest methods used in permafrost research and engineering and to discuss future plans to address climate change issues in permafrost areas. This workshop was an official International Polar Year (IPY) event organized jointly by the Otto Schmidt Laboratory for Polar and Marine Sciences (OSL) in St. Petersburg, the Permafrost Young Researchers Network (PYRN), and the Association of Polar Early Career Scientists (APECS).

The workshop provided insights into the latest techniques and methods used in permafrost research in fields as diverse as permafrost modeling, investigations of mountain ice segregation, bubbling from thermokarst lakes, and submarine permafrost detection. It brought together experts to provide young investigators with a multidisciplinary and cross‐border perspective on permafrost research, a much needed approach in a discipline marked by strong research history yet strongly entangled within national borders. Presentations and speaker biographies are now available on the conference Web site (http://pyrn.ways.org/activities/pyrn‐meetings/2007‐saint‐petersburg).
AGU Scientists Host Teacher Workshop in Ethiopia
Authors: Moldwin Mark , Yizengaw Endawoke , Scherrer Deborah K. , Rabellosoares M. Cristina , Reiff Patricia , Sumners Carolyn
Published: March 2008

When you look at a map of the world showing the location of ground‐based space physics instrumentation (radars, magnetometers, ionosondes, GPS dual‐frequency receivers, and lidars), you quickly recognize Africa's lack of space physics research infrastructure. One priority of the United Nations—sponsored International Heliophysical Year (IHY) is the development of such an infrastructure in Africa.

Satellite data have shown that the equatorial ionospheric density structures, especially at the equatorial region in the African continent, respond to space weather effects differently than do other parts of the Earth. For example, in the African equatorial region, satellite observations show that depleted density irregularities known as bubbles are much deeper than the bubbles observed in any other longitudinal sectors, and are very active year round in Africa compared with other regions. Observations also show that the depleted density in Africa rises to high altitude (up to 1000+ kilometers) more frequently compared with other longitudes.
Increases Proposed for U.S. Energy Department, But EPA Funding Would Be Cut
Authors: Showstack Randy
Published: March 2008

The Bush administration's proposed fiscal year (FY) 2009 budget request would cut the U.S. Environmental Protection Agency's (EPA) funding to US$7.14 billion, a decrease of $330 million, or 4.4%, from the 2008 funding level. However, the administration's proposed budget request for the U.S. Department of Energy (DOE) would boost that agency's funding to $25 billion, an increase of $1.07 billion over 2008.

The EPA budget request would allow the agency to “continue to deliver environmental results today, as well as keep EPA on course to deliver a cleaner, healthier tomorrow,” according to EPA administrator Stephen Johnson. “This budget represents government at its best: It helps EPA meet our environmental goals while being responsible stewards of taxpayers' dollars.”
Tamisiea Receives 2007 Geodesy Section Award
Authors: Leuliette Eric , Tamisiea Mark
Published: March 2008

Mark Tamisiea has made significant and original advances in solid Earth geophysics and has begun to be an important leader in the geodesy community. He has actively applied models of glacial isostatic adjustment and gravity data from the GRACE mission to address practical problems in ice sheet history, sea level variation, and short‐ and long‐term solid Earth deformation.

After his undergraduate training in physics at Grinnell College, Mark completed a Ph.D. with John Wahr at the University of Colorado. He was a postdoctoral fellow with Jerry Mitrovica at the University of Toronto and a geophysicist at the Harvard Smithsonian Observatory with Jim Davis. At present, he is a research scientist at Proudman Oceanographic Laboratory.
Toward Safer Thrombolytic Agents in Stroke: Molecular Requirements for NMDA Receptor-Mediated Neurotoxicity
Authors: Lopez-Atalaya Jose P , Roussel Benoit D , Levrat Denis , Parcq Jérôme , Nicole Olivier , Hommet Yannick , Benchenane Karim , Castel Hervé , Leprince Jérôme , To Van Denis , Bureau Ronan , Rault Sylvain , Vaudry Hubert , Petersen Karl-Uwe , Santos Jana Sopkova-de Oliveira , Ali Carine , Vivien Denis
Published: March 2008

Current thrombolytic therapy for acute ischemic stroke with tissue-type plasminogen activator (tPA) has clear global benefits. Nevertheless, evidences argue that in addition to its prohemorrhagic effect, tPA might enhance excitotoxic necrosis. In the brain parenchyma, tPA, by binding to and then cleaving the amino-terminal domain (ATD) of the NR1 subunit of N-methyl-d-aspartate (NMDA) glutamate receptors, increases calcium influx to toxic levels. We show here that tPA binds the ATD of the NR1 subunit by a two-sites system ( KD=24 nmol/L). Although tenecteplase (TNK) and reteplase also display two-sites binding profiles, the catalytically inactive mutant TNKS478A displays a one-site binding profile and desmoteplase (DSPA), a kringle 2 (K2) domain-free plasminogen activator derived from vampire bat, does not interact with NR1. Moreover, we show that in contrast to tPA, DSPA does not promote excitotoxicity. These findings, together with three-dimensional (3D) modeling, show that a critical step for interaction of tPA with NR1 is the binding of its K2 domain, followed by the binding of its catalytic domain, which in turn cleaves the NR1 subunit at its ATD, leading to a subsequent potentiation of NMDA-induced calcium influx and neurotoxicity. This could help design safer new generation thrombolytic agents for stroke treatment.
Long-term enhancement of skeletal muscle mass and strength by single gene administration of myostatin inhibitors
Authors: Haidet Amanda M. , Rizo Liza , Handy Chalonda , Umapathi Priya , Eagle Amy , Shilling Chris , Boue Daniel , Martin Paul T. , Sahenk Zarife , Mendell Jerry R. , Kaspar Brian K.
Published: March 2008

Increasing the size and strength of muscles represents a promising therapeutic strategy for musculoskeletal disorders, and interest has focused on myostatin, a negative regulator of muscle growth. Various myostatin inhibitor approaches have been identified and tested in models of muscle disease with varying efficacies, depending on the age at which myostatin inhibition occurs. Here, we describe a one-time gene administration of myostatin-inhibitor-proteins to enhance muscle mass and strength in normal and dystrophic mouse models for >2 years, even when delivered in aged animals. These results demonstrate a promising therapeutic strategy that warrants consideration for clinical trials in human muscle diseases.
Possible involvement of SINEs in mammalian-specific brain formation
Authors: Sasaki Takeshi , Nishihara Hidenori , Hirakawa Mika , Fujimura Koji , Tanaka Mikiko , Kokubo Nobuhiro , Kimura-Yoshida Chiharu , Matsuo Isao , Sumiyama Kenta , Saitou Naruya , Shimogori Tomomi , Okada Norihiro
Published: March 2008

Retroposons, such as short interspersed elements (SINEs) and long interspersed elements (LINEs), are the major constituents of higher vertebrate genomes. Although there are many examples of retroposons' acquiring function, none has been implicated in the morphological innovations specific to a certain taxonomic group. We previously characterized a SINE family, AmnSINE1, members of which constitute a part of conserved noncoding elements (CNEs) in mammalian genomes. We proposed that this family acquired genomic functionality or was exapted after retropositioning in a mammalian ancestor. Here we identified 53 new AmnSINE1 loci and refined 124 total loci, two of which were further analyzed. Using a mouse enhancer assay, we demonstrate that one SINE locus, AS071, 178 kbp from the gene
FGF8
(fibroblast growth factor 8), is an enhancer that recapitulates
FGF8
expression in two regions of the developing forebrain, namely the diencephalon and the hypothalamus. Our gain-of-function analysis revealed that
FGF8
expression in the diencephalon controls patterning of thalamic nuclei, which act as a relay center of the neocortex, suggesting a role for FGF8 in mammalian-specific forebrain patterning. Furthermore, we demonstrated that the locus, AS021, 392 kbp from the gene
SATB2
, controls gene expression in the lateral telencephalon, which is thought to be a signaling center during development. These results suggest important roles for SINEs in the development of the mammalian neuronal network, a part of which was initiated with the exaptation of AmnSINE1 in a common mammalian ancestor.
Advantages of a single-cycle production assay to study cell culture-adaptive mutations of hepatitis C virus
Authors: Russell Rodney S. , Meunier Jean-Christophe , Takikawa Shingo , Faulk Kristina , Engle Ronald E. , Bukh Jens , Purcell Robert H. , Emerson Suzanne U.
Published: March 2008

The JFH1 strain of hepatitis C virus (HCV) is unique among HCV isolates, in that the wild-type virus can traverse the entire replication cycle in cultured cells. However, without adaptive mutations, only low levels of infectious virus are produced. In the present study, the effects of five mutations that were selected during serial passage in Huh-7.5 cells were studied. Recombinant genomes containing all five mutations produced 3–4 logs more infectious virions than did wild type. Neither a coding mutation in NS5A nor a silent mutation in E2 was adaptive, whereas coding mutations in E2, p7, and NS2 all increased virus production. A single-cycle replication assay in CD81-deficient cells was developed to study more precisely the effect of the adaptive mutations. The E2 mutation had minimal effect on the amount of infectious virus released but probably enhanced entry into cells. In contrast, both the p7 and NS2 mutations independently increased the amount of virus released.
Recent moon jelly (Aurelia sp.1) blooms in Korean coastal waters suggest global expansion: examples inferred from mitochondrial COI and nuclear ITS-5.8S rDNA sequences
Authors: Ki Jang-Seu , Hwang Dae-Sik , Shin Kyoungsoon , Yoon Won Duk , Lim Donghyun , Kang Young Shil , Lee Yoon , Lee Jae-Seong
Published: March 2008

Ki, J-S., Hwang, D-S., Shin, K., Yoon, W. D., Lim, D., Kang, Y. S., Lee, Y., and Lee, J-S. 2008. Recent moon jelly (Aurelia sp.1) blooms in Korean coastal waters suggest global expansion: examples inferred from mitochondrial COI and nuclear ITS-5.8S rDNA sequences. – ICES Journal of Marine Science, 65: 443–452. The moon jelly Aurelia was found recently in Korean coastal environments, and its dense blooms caused economic losses for fisheries and power plants. The species is tentatively recognized as Aurelia aurita; yet, its identity and origin remain elusive. To find reliable molecular evidence for its identity, we determined the DNA sequence of the mitochondrial cytochrome c oxidase subunit I gene and nuclear ITS-5.8S rDNA of specimens collected from different Korean locations. We compared the nuclear and mitochondrial DNA data among specimens and demonstrated that all Korean Aurelia have an identical genotype. BLAST searches demonstrated that the Korean Aurelia matched the previously designated Aurelia sp.1. Parsimony and relevant phylogenetic analyses of the genus Aurelia demonstrated that the genotypes of Korean, Japanese, and Californian Aurelia sp.1 were nearly identical (>99.6% similarity), whereas they were significantly different (<84.1% similarity) from other Aurelia. This suggests that Aurelia sp.1, which occur in the three regions, are descendants of a single population and may have dispersed from one location. However, the dispersal time and origin of Aurelia sp.1 still remain uncertain.
Safeguarding Children
Authors: Wilson Anna
Published: March 2008

Child abuse occurs where a child is harmed or not protected from harm. Over recent years the term ‘ safeguarding’, or putting measures in place to improve childrens' safety and prevent abuse, has been introduced. Child protection is the part of the safeguarding process where it is necessary to intervene when there is a reasonable belief that a child is at risk of significant harm, and should be seen in the broader context of safeguarding and promoting the welfare of children.
Historical and other studies of science, technology and medicine in the University of Edinburgh
Authors: Henry John
Published: March 2008

Considering Edinburgh's prominence in the historical development of the sciences, it might be expected that the formal study of the history of science would appear as a significant feature in its university. Alas, this is not so, although there are signs that things are beginning to improve. If there is a deficit in historical studies of science, however, it is surely outweighed by Edinburgh's remarkable contribution to the sociological study of science and technology, which has even given rise to the designation ‘Edinburgh School’ to refer to a characteristic approach to the study of science that was developed in Edinburgh University. In this report I briefly consider the history of these and other aspects of the study of science, technology and medicine in Edinburgh as well as presenting an outline of the current picture.
A review of the diversity and evolution of photonic structures in butterflies, incorporating the work of John Huxley (The Natural History Museum, London from 1961 to 1990)
Authors: Ingram A.L , Parker A.R
Published: March 2008

The photonic structures of butterfly wings are among the most anatomically diverse of all those in nature, giving rise to an unrivalled display of structural colours. These have recently become the focus of research by workers in a variety of disciplines, stimulated by their potential applications to technology (‘biomimetics’). This interest, together with the discovery of unpublished electron micrographs taken by the late Dr John Huxley (Natural History Museum, London), prompted this review of butterfly photonics in general. The current work provides a synopsis of the literature to date, covering the diversity and evolution of these optical structures and incorporating Huxley's work, which represents an important biomimetic and evolutionary database on its own. This review deals with butterfly photonic devices according to the parts of the butterfly scales on which they occur. In this way, the information is ripe for evolutionary study.