bluuebunny/crossref_metadata_2025 huggingface dataset:
Density functional theory study of CO2 capture with transition metal oxides and hydroxides
Authors: Zhang Bo , Duan Yuhua , Johnson Karl
Published: February 2012

We have used density functional theory (DFT) employing several different exchange-correlation functionals (PW91, PBE, PBEsol, TPSS, and revTPSS) coupled with lattice dynamics calculations to compute the thermodynamics of CO2 absorption/desorption reactions for selected transition metal oxides, (TMO), and hydroxides, TM(OH)2, where TM = Mn, Ni, Zn, and Cd. The van't Hoff plots, which describe the reaction equilibrium as a function of the partial pressures of CO2 and H2O as well as temperature, were computed from DFT total energies, complemented by the free energy contribution of solids and gases from lattice dynamics and statistical mechanics, respectively. We find that the PBEsol functional calculations are generally in better agreement with experimental phase equilibrium data compared with the other functionals we tested. In contrast, the formation enthalpies of the compounds are better computed with the TPSS and revTPSS functionals. The PBEsol functional gives better equilibrium properties due to a partial cancellation of errors in the enthalpies of formation. We have identified all CO2 capture reactions that lie on the Gibbs free energy convex hull as a function of temperature and the partial pressures of CO2 and H2O for all TMO and TM(OH)2 systems studied here.
Generalized five-dimensional Kepler system, Yang-Coulomb monopole, and Hurwitz transformation
Authors: Marquette Ian
Published: February 2012

The 5D Kepler system possesses many interesting properties. This system is superintegrable and also with a su(2) non-Abelian monopole interaction (Yang-Coulomb monopole). This system is also related to an 8D isotropic harmonic oscillator by a Hurwitz transformation. We introduce a new superintegrable Hamiltonian that consists in a 5D Kepler system with new terms of Smorodinsky-Winternitz type. We obtain the integrals of motion of this system. They generate a quadratic algebra with structure constants involving the Casimir operator of a so(4) Lie algebra. We also show that this system remains superintegrable with a su(2) non-Abelian monopole (generalized Yang-Coulomb monopole). We study this system using parabolic coordinates and obtain from Hurwitz transformation its dual that is an 8D singular oscillator. This 8D singular oscillator is also a new superintegrable system and multiseparable. We obtained its quadratic algebra that involves two Casimir operators of so(4) Lie algebras. This correspondence is used to obtain algebraically the energy spectrum of the generalized Yang-Coulomb monopole.
The structure of liquid N-methyl pyrrolidone probed by x-ray scattering and molecular simulations
Authors: Gontrani Lorenzo , Caminiti Ruggero
Published: February 2012

The structural properties of liquid N-methyl pyrrolidone have been investigated by combining energy dispersive x-ray diffraction experiments and molecular dynamics simulations with generalized AMBER force field. A very good agreement between theoretical and experimental diffraction patterns was achieved. The analysis of the radial distribution functions shows that the methyl-carbonyl H-bond network observed in the crystal structure is partly preserved in the liquid structure.
Quantitative comparison of two independent lateral force calibration techniques for the atomic force microscope
Authors: Barkley Sarice S. , Deng Zhao , Gates Richard S. , Reitsma Mark G. , Cannara Rachel J.
Published: February 2012

Two independent lateral-force calibration methods for the atomic force microscope (AFM)—the hammerhead (HH) technique and the diamagnetic lateral force calibrator (D-LFC)—are systematically compared and found to agree to within 5 % or less, but with precision limited to about 15 %, using four different tee-shaped HH reference probes. The limitations of each method, both of which offer independent yet feasible paths toward traceable accuracy, are discussed and investigated. We find that stiff cantilevers may produce inconsistent D-LFC values through the application of excessively high normal loads. In addition, D-LFC results vary when the method is implemented using different modes of AFM feedback control, constant height and constant force modes, where the latter is more consistent with the HH method and closer to typical experimental conditions. Specifically, for the D-LFC apparatus used here, calibration in constant height mode introduced errors up to 14 %. In constant force mode using a relatively stiff cantilever, we observed an ≈ 4 % systematic error per μN of applied load for loads ≤ 1 μN. The issue of excessive load typically emerges for cantilevers whose flexural spring constant is large compared with the normal spring constant of the D-LFC setup (such that relatively small cantilever flexural displacements produce relatively large loads). Overall, the HH method carries a larger uncertainty, which is dominated by uncertainty in measurement of the flexural spring constant of the HH cantilever as well as in the effective length dimension of the cantilever probe. The D-LFC method relies on fewer parameters and thus has fewer uncertainties associated with it. We thus show that it is the preferred method of the two, as long as care is taken to perform the calibration in constant force mode with low applied loads.
Development of high-voltage pulse-slicer unit with variable pulse duration for pulse radiolysis system
Authors: Upadhyay J. , Sharma M. L. , Navathe C. P. , Toley M. A. , Shinde S. J. , Nadkarni S. A. , Sarkar S. K.
Published: February 2012

A high-voltage pulse-slicer unit with variable pulse duration has been developed and integrated with a 7 MeV linear electron accelerator (LINAC) for pulse radiolysis investigation. The pulse-slicer unit provides switching voltage from 1 kV to 10 kV with rise time better than 5 ns. Two MOSFET based 10 kV switches were configured in differential mode to get variable duration pulses. The high-voltage pulse has been applied to the deflecting plates of the LINAC for slicing of electron beam of 2 μs duration. The duration of the electron beam has been varied from 30 ns to 2 μs with the optimized pulse amplitude of 7 kV to get corresponding radiation doses from 6 Gy to 167 Gy.
Note: A high dynamic range, linear response transimpedance amplifier
Authors: Eckel S. , Sushkov A. O. , Lamoreaux S. K.
Published: February 2012

We have built a high dynamic range (nine decade) transimpedance amplifier with a linear response. The amplifier uses junction-gate field effect transistors (JFETs) to switch between three different resistors in the feedback of a low input bias current operational amplifier. This allows for the creation of multiple outputs, each with a linear response and a different transimpedance gain. The overall bandwidth of the transimpedance amplifier is set by the bandwidth of the most sensitive range. For our application, we demonstrate a three-stage amplifier with transimpedance gains of approximately 109Ω, 3 × 107Ω, and 104Ω with a bandwidth of 100 Hz.
Two-point approximation to the Kramers problem with coloured noise
Authors: Campos Daniel , Méndez Vicenç
Published: February 2012

We present a method, founded on previous renewal approaches as the classical Wilemski-Fixman approximation, to describe the escape dynamics from a potential well of a particle subject to non-Markovian fluctuations. In particular, we show how to provide an approximated expression for the distribution of escape times if the system is governed by a generalized Langevin equation (GLE). While we show that the method could apply to any friction kernel in the GLE, we focus here on the case of power-law kernels, for which extensive literature has appeared in the last years. The method presented (termed as two-point approximation) is able to fit the distribution of escape times adequately for low potential barriers, even if conditions are far from Markovian. In addition, it confirms that non-exponential decays arise when a power-law friction kernel is considered (in agreement with related works published recently), which questions the existence of a characteristic reaction rate in such situations.
Temperature dependence of Raman-active optical phonons in Bi2Se3 and Sb2Te3
Authors: Kim Y. , Chen X. , Wang Z. , Shi J. , Miotkowski I. , Chen Y. P. , Sharma P. A. , Lima Sharma A. L. , Hekmaty M. A. , Jiang Z. , Smirnov D.
Published: February 2012

Inelastic light scattering spectra of Bi2Se3 and Sb2Te3 single crystals have been measured over the temperature range from 5 K to 300 K. The temperature dependence of dominant A1g2 phonons shows similar behavior in both materials. The temperature dependence of the peak position and linewidth is analyzed considering the anharmonic decay of optical phonons and the material thermal expansion. This work suggests that Raman spectroscopy can be used for thermometry in Bi2Se3- and Sb2Te3-based devices in a wide temperature range.
Using Zintl-Klemm intermetallics in oxide-semiconductor heteroepitaxy
Authors: Demkov A. A. , Seo H. , Zhang X. , Ramdani J.
Published: February 2012

We propose using the Zintl-Klemm (Z-K) bonding to engineer transition layers that provide wetting between ionic oxides and covalent semiconductors to ensure two-dimensional epitaxial growth. Using density functional theory to test this concept, we consider the thermodynamics of wetting at the GaAs/SrTiO3 interface, and identify Sr aluminide SrAl2 as the Z-K wetting layer. We discuss the atomic structure and bonding at the interface, and estimate the conduction band discontinuity to be 0.6 eV, in good agreement with recent experiment.
Charge redistribution in piezoelectric energy harvesters
Authors: Stewart Mark , Weaver Paul M. , Cain Markys
Published: February 2012

Piezoelectric energy harvesting cantilevers provide a simple, compact low cost construction method for energy harvesting from vibrational sources. Beam theory predicts a linear distribution of strain along the length of the beam, but the conversion of this strain to electrical energy is dependent on the coverage of the beam with active material. In this paper, we demonstrate how re-distribution of charge within the piezoelectric leads to losses that can be as high as 25% of the potential generated power. Reducing the area coverage of the piezoelectric is shown to significantly improve cantilever power output, with the optimum coverage being 2/3.
Communication: Thermodynamics of condensed matter with strong pressure-energy correlations
Authors: Ingebrigtsen Trond S. , Bøhling Lasse , Schrøder Thomas B. , Dyre Jeppe C.
Published: February 2012

We show that for any liquid or solid with strong correlation between its NVT virial and potential-energy equilibrium fluctuations, the temperature is a product of a function of excess entropy per particle and a function of density, T = f(s)h(ρ). This implies that (1) the system's isomorphs (curves in the phase diagram of invariant structure and dynamics) are described by h(ρ)/T = Const., (2) the density-scaling exponent is a function of density only, and (3) a Grüneisen-type equation of state applies for the configurational degrees of freedom. For strongly correlating atomic systems one has h(ρ) = ∑nCnρn/3 in which the only non-zero terms are those appearing in the pair potential expanded as v(r) = ∑nvnr−n. Molecular dynamics simulations of Lennard-Jones type systems confirm the theory.
Altering the sulfur content in the propanethiol plasma polymers using the capacitive-to-inductive mode transition in inductively coupled plasma discharge
Authors: Thiry Damien , Britun Nikolay , Konstantinidis Stephanos , Dauchot Jean-Pierre , Denis Laurent , Snyders Rony
Published: February 2012

The effect of the transition from capacitive (E) to inductive (H) mode on propanethiol plasma polymer films properties was investigated by optical emission as well as by x-ray photoelectron spectroscopy. The E mode is characterized by low deposition rate and by high sulfur content in the films (∼40% vs ∼20% in H mode). After aging, a strong decrease of sulfur to carbon content (from ∼0.75 to 0.13), attributed to desorption of unbounded sulfur-based molecules (e.g., H2S), is detected at low power in E mode. The importance of the E-H transition for altering the film properties is highlighted.
Intrinsic electroresistance of Sm0.60Sr0.40MnO3 and Sm0.55Sr0.45MnO3
Authors: Mahmud S. T. , Saber M. M. , Alagoz H. S. , Bouveyron R. , Jung J. , Chow K. H.
Published: February 2012

We report investigations of the intrinsic electroresistance of polycrystalline Sm0.60Sr0.40MnO3 and Sm0.55Sr0.45MnO3 that are synthesized in the same way. These experiments were carried out with excitation using short current pulses, and are analyzed with the goal of drastically reducing the contribution of Joule heating on the electroresistance. We find that the changes of the intrinsic electroresistance with the current density are much more significant in Sm0.60Sr0.40MnO3 compared to Sm0.55Sr0.45MnO3. These results are compared with other recent measurements of the electroresistance in the same compositions. The possible underlying mechanisms for our observed composition-dependent changes are also discussed.
Atomically flat interface between a single-terminated LaAlO3 substrate and SrTiO3 thin film is insulating
Authors: Liu Z. Q. , Huang Z. , Lü W. M. , Gopinadhan K. , Wang X. , Annadi A. , Venkatesan T. , Ariando
Published: February 2012

The surface termination of (100)-oriented LaAlO3 (LAO) single crystals was examined by atomic force microscopy and optimized to produce a single-terminated atomically flat surface by annealing. Then the atomically flat STO film was achieved on a single-terminated LAO substrate, which is expected to be similar to the n-type interface of two-dimensional electron gas (2DEG), i.e., (LaO)-(TiO2). Particularly, that can serve as a mirror structure for the typical 2DEG heterostructure to further clarify the origin of 2DEG. This newly developed interface was determined to be highly insulating. Additionally, this study demonstrates an approach to achieve atomically flat film growth based on LAO substrates.
Assessing the Accuracy of Radio Astronomy Source-Finding Algorithms
Authors: Westerlund S. , Harris C. , Westmeier T.
Published: February 2012

This work presents a method for determining the accuracy of a source finder algorithm for spectral line radio astronomy data and the Source Finder Accuracy Evaluator (SFAE), a program that implements this method. The accuracy of a source finder is defined in terms of its completeness, reliability, and accuracy of the parameterisation of the sources that were found. These values are calculated by executing the source finder on an image with a known source catalogue, then comparing the output of the source finder to the known catalogue. The intended uses of SFAE include determining the most accurate source finders for use in a survey, determining the types of radio sources a particular source finder is capable of accurately locating, and identifying optimum parameters and areas of improvement for these algorithms. This paper demonstrates a sample of accuracy information that can be obtained through this method, using a simulated ASKAP data cube and the duchamp source finder.
A method of finding optimal weight factors for compound identification in gas chromatography–mass spectrometry
Authors: Kim Seongho , Koo Imhoi , Wei Xiaoli , Zhang Xiang
Published: February 2012

Motivation: The compound identification in gas chromatography–mass spectrometry (GC–MS) is achieved by matching the experimental mass spectrum to the mass spectra in a spectral library. It is known that the intensities with higher m/z value in the GC–MS mass spectrum are the most diagnostic. Therefore, to increase the relative significance of peak intensities of higher m/z value, the intensities and m/z values are usually transformed with a set of weight factors. A poor quality of weight factors can significantly decrease the accuracy of compound identification. With the significant enrichment of the mass spectral database and the broad application of GC–MS, it is important to re-visit the methods of discovering the optimal weight factors for high confident compound identification.

Results: We developed a novel approach to finding the optimal weight factors only through a reference library for high accuracy compound identification. The developed approach first calculates the ratio of skewness to kurtosis of the mass spectral similarity scores among spectra (compounds) in a reference library and then considers a weight factor with the maximum ratio as the optimal weight factor. We examined our approach by comparing the accuracy of compound identification using the mass spectral library maintained by the National Institute of Standards and Technology. The results demonstrate that the optimal weight factors for fragment ion peak intensity and m/z value found by the developed approach outperform the current weight factors for compound identification.

Availability: The results and R package are available at http://stage.louisville.edu/faculty/x0zhan17/software/ software-development.

Contact:  s0kim023@louisville.edu; xiang.zhang@louisville.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Evaluation of Preventive Fungicide Applications for Fairy Ring Control in Golf Putting Greens and In Vitro Sensitivity of Fairy Ring Species to Fungicides
Authors: Miller G. L. , Soika M. D. , Tredway L. P.
Published: February 2012

Fairy ring species induce symptoms on putting greens mostly indirectly, by modifying the soil physical or chemical properties. Therefore, preventive rather than curative fungicide applications may be more effective in managing fairy ring. Two field experiments were conducted on a creeping bentgrass research green to evaluate fairy ring control from preventive fungicide applications. A 3-year study investigated the optimal rate and soil temperature-based timing of a preventive application of triadimefon and tebuconazole. A 2-year study evaluated the impact of irrigation timing and fungicide + surfactant tank mixtures on the efficacy of preventive applications of triadimefon and triticonazole. Fungicide-treated plots in both studies exhibited less fairy ring severity than untreated plots. Data suggest that a 5-day average soil temperature range of 13 to 16°C may be suitable for initiating preventive applications. Symptoms occurred earlier in plots treated with a surfactant tank mix than in those treated with fungicide alone. Irrigation timing had no effect on fungicide performance. The sensitivity of 16 isolates representing major fairy ring species to flutolanil, propiconazole, tebuconazole, triadimefon, and triticonazole was determined with a mycelial growth assay. No significant differences in fungicide sensitivity were detected among species. Isolates had significantly higher 50% effective concentration values for triadimefon than for the other fungicides tested.
Transaxillary Approach Short- and Mid-Term Results in a Single-Center Experience
Authors: Cioni Micaela , Taramasso Maurizio , Giacomini Andrea , Montorfano Matteo , Latib Azeem , Colombo Antonio , Alfieri Ottavio , Maisano Francesco
Published: February 2012

Objective

Transcatheter aortic valve implantation (TAVI) is increasingly accepted as an alternative procedure in patients with severe, symptomatic aortic stenosis and high risk for surgical aortic valve replacement. Transfemoral (TF) approach is the first option when feasible, but in case of peripheral vascular disease this approach is precluded. In our institution, for this kind of patients we considered transaxillary (TAx) approach as second choice and transapical (TAp) or transaortic (TAa) as last routes. This study describes short- and mid-term morbidity and mortality for TAx approach.

Methods

From November 2007 to March 2011, 284 patients underwent TAVI at our site; 229 treated by TF approach, 22 TAp, 2 TAa, and 31 TAx. Four patients were treated with an Edwards Sapien valve (Edwards Lifesciences, Inc., Irvine, CA USA) with TAx approach and 27 with CoreValve Revalving System (Medtronic Inc., Minneapolis, MN USA). TAx TAVI was performed in cath-laboratory with local anesthesia and mild sedation by a multispeciality valve team. We analyzed major adverse cardiac and cerebrovascular events, major adverse valve-related events, vascular complications, and 30 days and 6 months mortality.

Results

The procedural success rate (successful implantation of the device without intraprocedural mortality or need to conversion to open heart surgery) was 96.8% (30/31). Major adverse valve-related events were 12.9% (4/31). 30-day mortality was 6.4% (2/31) and actuarial survival at 6 months was 82.95% ± 7.96%. In one patient, procedure was converted to a TF CoreValve in emergency for hemodynamic instability after valvuloplasty due to severe difficulty to introduce the Edwards valve in the subclavian artery.

Conclusions

TAx approach is a feasible and technically simple procedure with encouraging results considering morbidity and mortality at short- and mid-term follow-up. TAx is a valid solution in patients with contraindications to TF approach and it is an alternative approach potentially less invasive than TAp or TAa.
Experience with Robotic Lobectomy for Lung Cancer
Authors: Veronesi Giulia , Agoglia Bernardo G , Melfi Franca , Maisonneuve Patrick , Bertolotti Raffaella , Bianchi Paolo P. , Rocco Bernardo , Borri Alessandro , Gasparri Roberto , Spaggiari Lorenzo
Published: February 2012

Objective

In this study, we analyze our experience so far with robotic pulmonary lobectomy, compare it with published data, and suggest a learning curve for the operation.

Methods

Ninety-one patients with suspected or proven clinical stage I–III lung cancer underwent robotic lobectomy. Selection criteria included lesion ≤5 cm and normal respiratory function. One surgeon performed the operations using the da Vinci system with three ports and a 3-cm utility thoracotomy.

Results

Median duration of operation was 239 (range 85–411) minutes, 260 minutes in the first 18 patients and 221 minutes in the remaining 73 cases (P = 0.01). Median hospitalization declined from 6 days in the first 18 cases to 5 days in the remaining cases (P = 0.002). Conversion rate and number of complications reduced nonsignificantly from the initial to later series. Major complications occurred in 11% of the first 18 cases and 4% of the later cases. The number of lymph nodes removed did not change over the two series. There was no 30-day postoperative mortality. After a median follow-up of 24 months, 80 of 91 patients were alive with no sign of disease.

Conclusions

Our data suggest that about 20 operations are required to achieve surgical competence. Robotic lobectomy appears safe, oncologically radical, and associated with shorter postoperative hospitalization than open surgery.
Host Response to Probiotics Determined by Nutritional Status of Rotavirus‐infected Neonatal Mice
Authors: Preidis Geoffrey A. , Saulnier Delphine M. , Blutt Sarah E. , Mistretta Toni‐Ann , Riehle Kevin P. , Major Angela M. , Venable Susan F. , Barrish James P. , Finegold Milton J. , Petrosino Joseph F. , Guerrant Richard L. , Conner Margaret E. , Versalovic James
Published: February 2012

Objectives:

Beneficial microbes and probiotics are promising agents for the prevention and treatment of enteric and diarrheal diseases in children; however, little is known about their in vivo mechanisms of action. We used a neonatal mouse model of rotavirus diarrhea to gain insight into how probiotics ameliorate acute gastroenteritis.

Methods:

Rotavirus‐infected mice were treated with 1 of 2 strains of human‐derived Lactobacillus reuteri. We assessed intestinal microbiome composition with 16S metagenomic sequencing, enterocyte migration and proliferation with 5‐bromo‐2′‐deoxyuridine, and antibody and cytokine concentrations with multiplex analyses of intestinal explant cultures.

Results:

Probiotics reduced diarrhea duration, improved intestinal histopathology, and enhanced intestinal microbiome richness and phylogenetic diversity. The magnitude of reduction of diarrhea by probiotics was strain specific and influenced by nutritional status. L reuteri DSM 17938 reduced diarrhea duration by 0, 1, and 2 days in underweight, normal weight, and overweight pups, respectively. The magnitude of reduction of diarrhea duration correlated with increased enterocyte proliferation and migration. Strain ATCC PTA 6475 reduced diarrhea duration by 1 day in all of the mice without increasing enterocyte proliferation. Both probiotic strains decreased concentrations of proinflammatory cytokines, including macrophage inflammatory protein‐1α and interleukin‐1β, in all of the animals, and increased rotavirus‐specific antibodies in all but the underweight animals. Body weight also influenced the host response to rotavirus, in terms of diarrhea duration, enterocyte turnover, and antibody production.

Conclusions:

These data suggest that probiotic enhancement of enterocyte proliferation, villus repopulation, and virus‐specific antibodies may contribute to diarrhea resolution, and that nutritional status influences the host response to both beneficial microbes and pathogens.
Different Clinical Manifestations Between Primary Gastrointestinal Malignancies and Benign Tumors in Children
Authors: Tay Chow‐Hong , Lee Hung‐Chang , Yeung Chun‐Yan , Chan Wai‐Tao , Jiang Chuen‐Bin , Liang Der‐Cherng
Published: February 2012

Objective:

The purpose of the present study was to review the different clinical manifestations of primary gastrointestinal (GI) malignancies and benign tumors in pediatric patients.

Methods:

The demographic data, duration to diagnosis, clinical features, laboratory data, location and pathology of the tumors, and outcomes of pediatric patients from January 1984 to December 2009 were retrospectively reviewed.

Results:

A total of 24 GI malignancies and 62 benign tumors were diagnosed. Patients in the benign group were mostly diagnosed in the first decade of life (73%), whereas majority of patients with malignancies were older than 10 years (79%). The most common tumor location in the benign group was the colorectum, whereas in the malignant group, tumors were distributed equally in the small intestine and colorectum. The median duration from onset to diagnosis in the benign group was longer than that of the malignant group (P > 00.05). There was statistically significant increase in the presence of hematochezia in patients with benign tumor compared with those with malignancy (P < 00.05). Among the malignancies, 79% presented with abdominal pain, followed by weight loss (25%), anorexia (25%), palpable mass (25%), and fever (21%), with statistically significant differences compared with the benign group (P < 00.05). Anemia was found in 47% to 63% of patients in both groups (P > 00.05). Two patients with polyposis subsequently developed malignancy.

Conclusions:

Different manifestations of GI malignancies and benign tumors may help pediatricians to detect these early. Patients with polyposis should be aware of the risk of malignant change.
Iain MacIntyre. 30 August 1924 — 18 September 2008
Authors: Martin T. John
Published: February 2012

After a long illness borne with much grace and dignity, Iain MacIntyre died in London on 18 September 2008. He had led a most distinguished career over five decades as a major figure in the field of calcium-regulating hormones and bone metabolism, with his many scientific achievements marked by originality as well as biological and medical importance. Among his many accomplishments were the co-discovery with Harold Copp of the hormone calcitonin, whose glandular origin, structure and biological and medical functions he defined. Iain also was the first to isolate and sequence, with colleagues, the novel human neuropeptide calcitonin gene-related peptide, demonstrating its role as a potent vasodilator. Subsequently Iain defined the multiple phenotypic consequences attributable to nitric oxide production by different enzymes in a tissue-specific fashion. A major educational contribution was in conceiving and organizing an important biennial series of international endocrine meetings held between 1967 and 1981. These were memorable occasions, at which calcium metabolism and bone metabolism featured strongly, but so too did the latest topics in endocrinology. The meetings featured outstanding national and international speakers from many fields, and pushed the participants to think beyond the confines of their immediate interests. The published proceedings of those conferences are well worth re-reading, with much content that was prophetic and much that provides genuinely valuable history. These meetings played a very influential international role and had a seminal inspiring influence on the international careers of many young researchers who have since achieved major distinction. Iain was elected a Fellow of the Royal Society in 1996, served on a Sectional Committee, and was awarded the Buchanan Medal of the Society in 2006.
Towards an integrated experimental–theoretical approach for assessing the mechanistic basis of hair and feather morphogenesis
Authors: Painter K. J. , Hunt G. S. , Wells K. L. , Johansson J. A. , Headon D. J.
Published: February 2012

In his seminal 1952 paper, ‘The Chemical Basis of Morphogenesis’, Alan Turing lays down a milestone in the application of theoretical approaches to understand complex biological processes. His deceptively simple demonstration that a system of reacting and diffusing chemicals could, under certain conditions, generate spatial patterning out of homogeneity provided an elegant solution to the problem of how one of nature's most intricate events occurs: the emergence of structure and form in the developing embryo. The molecular revolution that has taken place during the six decades following this landmark publication has now placed this generation of theoreticians and biologists in an excellent position to rigorously test the theory and, encouragingly, a number of systems have emerged that appear to conform to some of Turing's fundamental ideas. In this paper, we describe the history and more recent integration between experiment and theory in one of the key models for understanding pattern formation: the emergence of feathers and hair in the skins of birds and mammals.
Analytical formulation of three-dimensional dynamic homogenization for periodic elastic systems
Authors: Norris A. N. , Shuvalov A. L. , Kutsenko A. A.
Published: February 2012

Homogenization of the equations of motion for a three-dimensional periodic elastic system is considered. Expressions are obtained for the fully dynamic effective material parameters governing the spatially averaged fields by using the plane wave expansion method. The effective equations are of Willis form with coupling between momentum and stress and tensorial inertia. The formulation demonstrates that the Willis equations of elastodynamics are closed under homogenization. The effective material parameters are obtained for arbitrary frequency and wavenumber combinations, including but not restricted to Bloch wave branches for wave propagation in the periodic medium. Numerical examples for a one-dimensional system illustrate the frequency dependence of the parameters on Bloch wave branches and provide a comparison with an alternative dynamic effective medium theory, which also reduces to Willis form but with different effective moduli.
Second-to-fourth digit ratio and facial shape in boys: the lower the digit ratio, the more robust the face
Authors: Meindl Konstanze , Windhager Sonja , Wallner Bernard , Schaefer Katrin
Published: February 2012

During human ontogeny, testosterone has powerful organizational and activational effects on the male organism. This has led to the hypothesis that the prenatal environment (as studied through the second-to-fourth digit ratio, 2D : 4D) is not only associated with robust adult male faces that are perceived as dominant and masculine, but also that there is an activational step during puberty. To test the latter, we collected digit ratios and frontal photographs of right-handed Caucasian boys (aged 4–11 years) along with age, body height and body weight. Using geometric morphometrics, we show a significant relationship between facial shape and 2D : 4D before the onset of puberty (explaining 14.5% of shape variation;
p
= 0.014 after 10 000 permutations,
n
= 17). Regression analyses depict the same shape patterns as in adults, namely that the lower the 2D : 4D, the smaller and shorter the forehead, the thicker the eyebrows, the wider and shorter the nose, and the larger the lower face. Our findings add to previous evidence that certain adult male facial characteristics that elicit attributions of masculinity and dominance are determined very early in ontogeny. This has implications for future studies in various fields ranging from social perception to life-history strategies.
Allometric scaling of foraging rate with trail dimensions in leaf-cutting ants
Authors: Bruce Andrew I. , Burd Martin
Published: February 2012

Leaf-cutting ants (
Atta
spp.) create physical pathways to support the transport of resources on which colony growth and reproduction depend. We determined the scaling relationship between the rate of resource acquisition and the size of the trail system and foraging workforce for 18 colonies of
Atta colombica
and
Atta cephalotes
. We examined conventional power-law scaling patterns, but did so in a multivariate analysis that reveals the simultaneous effects of forager number, trail length and trail width. Foraging rate (number of resource-laden ants returning to the nest per unit time) scaled at the 0.93 power of worker numbers, the –1.02 power of total trail length and the 0.65 power of trail width. These scaling exponents indicate that individual performance declines only slightly as more foragers are recruited to the workforce, but that trail length imposes a severe penalty on the foraging rate. A model of mass traffic flow predicts the allometric patterns for workforce and trail length, although the effect of trail width is unexpected and points to the importance of the little-known mechanisms that regulate a colony's investment in trail clearance. These results provide a point of comparison for the role that resource flows may play in allometric scaling patterns in other transport-dependent entities, such as human cities.
Visual interpolation for contour completion by the European cuttlefish (Sepia officinalis) and its use in dynamic camouflage
Authors: Zylinski Sarah , Darmaillacq Anne-Sophie , Shashar Nadav
Published: February 2012

Cuttlefish rapidly change their appearance in order to camouflage on a given background in response to visual parameters, giving us access to their visual perception. Recently, it was shown that isolated edge information is sufficient to elicit a body pattern very similar to that used when a whole object is present. Here, we examined contour completion in cuttlefish by assaying body pattern responses to artificial backgrounds of ‘objects’ formed from fragmented circles, these same fragments rotated on their axis, and with the fragments scattered over the background, as well as positive (full circles) and negative (homogenous background) controls. The animals displayed similar responses to the full and fragmented circles, but used a different body pattern in response to the rotated and scattered fragments. This suggests that they completed the broken circles and recognized them as whole objects, whereas rotated and scattered fragments were instead interpreted as small, individual objects in their own right. We discuss our findings in the context of achieving accurate camouflage in the benthic shallow-water environment.
Developmental Principles: Fact or Fiction
Authors: Durston A. J.
Published: February 2012

While still at school, most of us are deeply impressed by the underlying principles that so beautifully explain why the chemical elements are ordered as they are in the periodic table, and may wonder, with the theoretician Brian Goodwin, “whether there might be equally powerful principles that account for the awe-inspiring diversity of body forms in the living realm”. We have considered the arguments for developmental principles, conclude that they do exist and have specifically identified features that may generate principles associated with Hox patterning of the main body axis in bilaterian metazoa in general and in the vertebrates in particular. We wonder whether this exercise serves any purpose. The features we discuss were already known to us as parts of developmental mechanisms and defining developmental principles (how, and at which level?) adds no insight. We also see little profit in the proposal by Goodwin that there are principles outside the emerging genetic mechanisms that need to be taken into account. The emerging developmental genetic hierarchies already reveal a wealth of interesting phenomena, whatever we choose to call them.
Possible involvement of maize Rop1 in the defence responses of plants to viral infection
Authors: CAO YANYONG , SHI YAN , LI YONGQIANG , CHENG YUQIN , ZHOU TAO , FAN ZAIFENG
Published: February 2012

The expression of host genes can be altered during the process of viral infection. To investigate the viral infection‐induced up‐regulated gene expression changes of maize at different time intervals post‐inoculation with Sugarcane mosaic virus (SCMV), a suppression subtractive hybridization cDNA library was constructed. A total of 454 cDNA clones were identified to be viral infection‐induced up‐regulated genes. The influence of Rop1 on the infection of maize by SCMV was investigated. The results showed that transient silencing of the ZmRop1 gene through virus‐induced gene silencing enhanced the accumulation and systemic infection of SCMV and another potyvirus (Pennisetum mosaic virus) in maize plants, whereas transient over‐expression of ZmRop1 in maize protoplasts reduced SCMV accumulation. Furthermore, it was demonstrated that the heterologous expression of ZmRop1 impaired Potato virus X infection in Nicotiana benthamiana plants. These data suggest that ZmRop1 may play a role in plant defence responses to viral infection.
The expression of calcitonin receptor detected in malignant cells of the brain tumour glioblastoma multiforme and functional properties in the cell line A172
Authors: Wookey Peter J , McLean Catriona A , Hwang Peter , Furness Sebastian G B , Nguyen Sandy , Kourakis Angela , Hare David L , Rosenfeld Jeffrey V
Published: February 2012

Wookey P J, McLean C A, Hwang P, Furness S G B, Nguyen S, Kourakis A, Hare D L & Rosenfeld J V  (2012) Histopathology 60, 895–910

The expression of calcitonin receptor detected in malignant cells of the brain tumour glioblastoma multiforme and functional properties in the cell line A172

Aim:  Previous studies have indicated that expression of calcitonin receptor (CTR) could be induced in a proinflammatory environment. In the present study, CTR‐immunoreactivity (CTR‐ir) was investigated in brain tissue from patients with glioblastoma multiforme (GBM).

Methods and results:  In immunohistochemical analysis of GBM samples, tissues with complex glomeruloid structures surrounded by malignant cells were analysed for CTR‐ir using anti‐human CTR antibodies generated against two separate epitopes of CTR. CTR‐ir was associated predominantly with glial cells. Regions with CTR‐ir cells were found in 12 of 14 GBM tumours (P < 0.05). Using confocal microscopy, CTR‐ir cells were identified that were also positive for glial fibrillary acidic protein, nestin and CD133. Antibodies were verified using immunoblots and confocal microscopy of the Cercopithecus aethiops(COS)‐7 transfectants. Immunoblots of membrane preparations from the CTR‐positive cell lines demonstrated a major band (∼67 kDa) and minor band (∼52 kDa), but the intensity was reversed for the GBM cell line A172. In cultured A172 cells, functional studies demonstrated calcitonin stimulation of adenylyl cyclase and inhibition of extracellular‐regulated kinase (ERK)1/2 phosphorylation.

Conclusions:  The findings that (i) CTR was expressed by glioma cells in a majority of GBM tumours tested, (ii) CTR+/CD133+ cells were identified and (iii) second messenger systems were functionally modified by calcitonin in A172 cells suggest that CTR might be a useful therapeutic target in GBM.
Papillary thyroid carcinomas with and without BRAF  V600E mutations are morphologically distinct
Authors: Finkelstein Alexander , Levy Gillian H , Hui Pei , Prasad Avinash , Virk Renu , Chhieng David C , Carling Tobias , Roman Sanziana A , Sosa Julie A , Udelsman Robert , Theoharis Constantine G , Prasad Manju L
Published: February 2012

Finkelstein A, Levy G H, Hui P, Prasad A, Virk R, Chhieng D C, Carling T, Roman S A, Sosa J A, Udelsman R, Theoharis C G & Prasad M L  (2012) Histopathology 60, 1052–1059

Papillary thyroid carcinomas with and without BRAF V600E mutations are morphologically distinct

Aims:  The BRAF V600E mutation resulting in the production of an abnormal BRAF protein has emerged as the most frequent genetic alteration in papillary thyroid carcinomas (PTCs). This study was aimed at identifying distinctive features in tumours with and without the mutation.

Methods and results:  Thirty‐four mutation‐positive and 22 mutation‐negative tumours were identified by single‐strand conformation polymorphism of the amplified BRAF V600E region in the tumour DNA. Mutation‐positive tumours were more common in patients older than 45 years (24/33, P = 0.05), in classic (23/30, P = 0.01), tall cell (4/5) and oncocytic/Warthin‐like (2/2) variants of PTC, and in subcapsular sclerosing microcarcinomas (4/4). In contrast, all 12 follicular variants (P < 0.0001) and two diffuse sclerosing variants were negative for the mutation. Mutation‐positive tumours displayed infiltrative growth (32/34, P = 0.02), stromal fibrosis (33/34, P < 0.001), psammoma bodies (17/34, P = 0.05), plump eosinophilic tumour cells (22/34, P = 0.01), and classic fully developed nuclear features of PTC (33/34, P = 0.0001). Encapsulation was significantly associated with mutation‐negative tumours (15/22, P = 0.02).

Conclusions:  BRAF V600E mutation‐positive and negative PTCs are morphologically different. Recognition of their morphology may help in the selection of appropriate tumours for genetic testing.
Qualitative insights into the role and practice of Epilepsy Specialist Nurses in England: a focus group study
Authors: Hopkins Jan , Irvine Fiona
Published: February 2012

hopkins j. & Irvine F. (2012) Qualitative insights into the role and practice of Epilepsy Specialist Nurses in England: a focus group study. Journal of Advanced Nursing68(11), 2443–2453. doi: 10.1111/j.1365‐2648.2012.05941.x

Aim.  This article is a report of a study that aimed to explore Epilepsy Specialist Nurses’ perceptions of their professional role and the factors that may affect their practice.

Background.  Previous studies have demonstrated high patient satisfaction with the Epilepsy Specialist Nurse. Although UK national guidelines recommend that all individuals with epilepsy should have access to an epilepsy specialist nurse, many National Health Service trusts disregard these guidelines. The need to introduce cost efficiencies in the National Health Service means that the future of some epilepsy specialist nurses is threatened.

Design.  A qualitative study using focus groups was designed to elicit a rich understanding of the epilepsy specialist nurse role and its current challenges.

Methods.  Three focus groups were held with a total of 19 participants in the summer of 2009. Data were subjected to thematic framework analysis.

Findings.  The work was underpinned by high commitment to nursing values, which helped to define the role. Epilepsy specialist nurses were often the sole providers of expert and personalized care to meet patients’ complex needs. Policy and financially driven changes undermined professional identity and led to service diminution.

Conclusion.  The provision of epilepsy care in England remains variable and access to epilepsy specialist nurses is inequitable. Trusts are being seduced by the cost savings of reducing a specialist service but consequent gaps in service may drive up costs elsewhere. The challenge is for epilepsy specialist nurses to demonstrate their unique place in enhancing patient care and in improving health and well‐being.
Potential biases in colorectal cancer screening using faecal occult blood test
Authors: Riboe Dea Grip , Dogan Tilde Steen , Brodersen John
Published: February 2012

Background  Colorectal cancer (CRC) is one of the most common types of cancer in European countries and associated with a high mortality rate. A 16% relative risk reduction (RRR) of mortality was found in a meta‐analysis based on four randomized controlled trials (RCT) on CRC screening. The aim of this paper was to scrutinize these trials for potential biases and assess their influence on the screening trials.

Methods  The four RCTs were reviewed based on the principles of ‘Critical Appraisal of the Medical Literature’. Principal investigators of the four RCTs were contacted to clarify uncertainties in their study. Data were collected from The Danish Data Archives. Authors of the Cochrane review were contacted.

Results  Six biases were identified, of which five favour screening. Three of the biases identified were specific to CRC screening: type of diagnostic method, place of surgery and diagnostic delay.

Conclusion  The 16% RRR in CRC mortality found in the updated Cochrane review's meta‐analysis is overestimated.
Reference values for mental health assessment instruments: objectives and methods of the Leiden Routine Outcome Monitoring Study
Authors: Schulte‐van Maaren Yvonne W. M. , Carlier Ingrid V. E. , Giltay Erik J. , van Noorden Martijn S. , de Waal Margot W. M. , van der Wee Nic J. A. , Zitman Frans G.
Published: February 2012

Rationale, aims and objectives:  Routine outcome monitoring (ROM) was developed to establish the outcome of psychotherapeutic and pharmacological treatments through repeated assessments before, during and after treatment. Although standardization of psychiatric assessments and their reference values are essential for patient care, for various ROM instruments reference values are not available. The aim of the Leiden ROM Study is to generate reference values for 22 ROM instruments, covering generic and specific mood, anxiety and somatoform (MAS) disorders, for the general population. This article describes the extensive process of recruitment, as well as baseline characteristics of patient versus non‐patient groups.

Method:  Cross‐sectional study in randomly selected participants aged 18–65 years from the Dutch population, included through general practitioners.

Results:  Extensive demographic, psychosocial, mental health, and biological data from 1302 participants, recruited via general practitioners, were collected during a two‐hour standardized assessment including observer‐rated and self‐report scales. These data will be compared with corresponding data from 7840 patients with psychopathology who were referred to secondary care. On‐going quality control and calibration ensured maintenance of high quality during data collection.

Conclusions:  This reference group study for mental health assessments is the first study of this size carried out in the Netherlands. The results of this study are expected to be of value to secondary psychiatric care because they allow the indication of progress in health, treatment effect and possible termination of treatment. Additionally, the reference values can be used by primary care physicians as decision threshold for referral to specialized mental health care and vice versa.