bluuebunny/crossref_metadata_2025 huggingface dataset:
The Felicity of Aspectual For‐Phrases – Part 1: Homogeneity
Authors: Landman Fred , Rothstein Susan
Published: February 2012

This paper is the first in a series of two papers presenting recent developments concerning the interaction between aspectual classes of predicates and the semantics of aspectual for‐phrases. Aspectual for‐phrases can felicitously modify stative and activity predicates, but not (basic) accomplishment and achievement predicates. Earlier literature proposed that this is because aspectual for‐phrases must modify predicates which are homogeneous– meaning that the predicate spreads appropriately to subintervals – and it proposed a notion of homogeneity which is appropriate for stative predicates. We argue in this first paper that neither the earlier literature, nor later proposals have managed to come up with an adequate account of the felicity of aspectual for‐phrases with eventive predicates, and that, in particular, accomplishment and achievement predicates with bare arguments and iterative constructions remain challenges that these accounts cannot properly meet. We show that the problem lies in the notion of homogeneity for eventive predicates: the semantic tradition has provided us with static notions of homogeneity – insensitive to the arrow of time – but what is needed is a dynamic notion.
Integrated phased‐array switches for large‐scale photonic routing on chip
Authors: Soganci I.M. , Tanemura T. , Nakano Y.
Published: February 2012

Integrated phased‐array optical switches, having a high port‐count scalability and broad spectral coverage, can potentially be used as building blocks of large‐scale optical routers. In this article, recent works on monolithically integrated InP phased‐array switches and their applications to optical packet switching (OPS) are reviewed. After describing the theory of integrated phased‐array switches, experimental results on a single‐stage 1 × 16 switch, which features wavelength‐independent nanosecond switching characteristics, are presented. A series of OPS experiments, employing high‐bit‐rate optical packets with different modulation formats and a tunable optical buffering experiment are presented as potential applications of these switches. Finally, a large‐scale monolithic switch with as many as 100 ports is realized on a single photonic integrated circuit by cascading the phased‐array switches.
Electrical, Thermal, and Mechanical Characterization of Poly(propylene)/Carbon Nanotube/Clay Hybrid Composite Materials
Authors: Palza Humberto , Reznik Boris , Wilhelm Manfred , Arias Oscar , Vargas Alejandro
Published: February 2012

A set of hybrid composite materials based on a PP matrix with multiwalled CNTs and clay particles is prepared and characterized. The incorporation of clay particles into a percolated composite with 3 wt% CNT disrupts the percolation, decreasing dramatically the electrical conductivity. As expected for layered fillers, PP/CNT/clay hybrid composite materials and PP/clay composites display increases as high as 100 °C in the temperature for the maximum rate of weight loss. Surprisingly, these temperatures are just slightly higher than those of PP/CNT composites. PP/CNT composites display viscosities that are considerably lower than those of PP/clay composites. A synergistic effect of both fillers is observed in the viscoelastic response of PP/CNT/clay materials.

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Silencing of tumor suppressor genes RASSF1A, SLIT2, and WIF1 by promoter hypermethylation in hereditary breast cancer
Authors: Alvarez Carolina , Tapia Teresa , Cornejo Valeria , Fernandez Wanda , Muñoz Alex , Camus Mauricio , Alvarez Manuel , Devoto Luigi , Carvallo Pilar
Published: February 2012

Promoter hypermethylation is gaining strength as one of the main mechanisms through which tumor suppressor genes are silenced during tumor progression. Three tumor suppressor genes are frequently found methylated in their promoter, in concordance with absence of expression, RASSF1A, SLIT2, and WIF1. In addition, a previous array‐CGH analysis from our group showed that these genes are found in deleted genomic regions observed in hereditary breast cancer tumors. In the present work we analyzed the methylation status of these three tumor suppressor gene promoters in 47 hereditary breast cancer tumors. Promoter methylation status analysis of hereditary breast tumors revealed high methylation frequencies for the three genes (67% RASSF1A, 80% SLIT2, and 72% WIF1). Additionally, the presence of methylated PCR products was associated with absence of protein expression for the three genes and statistically significant for RASSF1A and WIF1. Interestingly, methylation of all the three genes was found in 4 out of 6 grade I invasive ductal carcinoma tumors. Association between RASSF1A methylation and DCIS tumors was found. These results suggest that silencing of these tumor suppressor genes is an early event in hereditary breast cancer, and could be a marker for pre‐malignant phenotypes. © 2012 Wiley Periodicals, Inc.
The association between Mediterranean diet adherence and Parkinson's disease
Authors: Alcalay Roy N. , Gu Yian , Mejia‐Santana Helen , Cote Lucien , Marder Karen S. , Scarmeas Nikolaos
Published: February 2012

Background:

Recent studies have demonstrated an association between a Mediterranean‐type diet and Alzheimer's risk. We assessed the association between Mediterranean‐type diet adherence and Parkinson's disease (PD) status.

Methods:

Two hundred and fifty‐seven PD participants and 198 controls completed the Willett semiquantitative questionnaire that quantifies diet during the past year. Scores were calculated using a 9‐point scale; higher scores indicated greater adherence to the Mediterranean‐type diet. Logistic regression models were used to assess the association between PD status and Mediterranean‐type diet, adjusting for caloric intake, age, sex, education, and ethnicity. Adjusted linear regression models were used to examine the association between Mediterranean‐type diet adherence and PD age at onset.

Results:

Higher Mediterranean‐type diet adherence was associated with reduced odds for PD after adjustment for all covariates (OR, 0.86; 95% CI, 0.77–0.97; P = .010). Lower Mediterranean‐type diet score was associated with earlier PD age at onset (β = 1.09; P = .006).

Conclusions:

PD patients adhere less than controls to a Mediterranean‐type diet. Dietary behavior may be associated with age at onset. © 2012 Movement Disorder Society
Comparison of enrollees and decliners of Parkinson disease sham surgery trials
Authors: Kim Scott Y.H. , Wilson Renee M. , Kim H. Myra , Holloway Robert G. , De Vries Raymond G. , Frank Samuel A. , Kieburtz Karl
Published: February 2012

Concerns have been raised that persons with serious illnesses participating in high‐risk research, such as PD patients in sham surgery trials, have unrealistic expectations and are vulnerable to exploitation. A comparison of enrollees and decliners of such research may provide insights about the adequacy of decision making by potential subjects. We compared 61 enrollees and 10 decliners of two phase II neurosurgical intervention (i.e., cellular and gene transfer) trials for PD regarding their demographic and clinical status, perceptions and attitudes regarding research risks, potential direct benefit, and societal benefit, and perspectives on the various potential reasons for and against participation. In addition to bivariate analyses, a logistic regression model examined variables regarding risks and benefits as predictors of participation status. Enrollees perceived lower risk of harm while tolerating higher risk of harm and were more action oriented, but did not have more advanced disease. Both groups rated hope for benefit as a strong reason to participate, whereas the fact that the study's purpose was not solely to benefit them was rated as “not a reason” against participation. Hope for benefit and altruism were rated higher than expectation of benefit as reasons in favor of participation for both groups. Enrollees and decliners are different in their views and attitudes toward risk. Although both are attracted to research because of hopes of personal benefit, this hope is clearly distinguishable from an expectation of benefit and does not imply a failure to understand the main purpose of research. © 2012 Movement Disorder Society
From density functional steric analysis and molecular electrostatic potential to the estimation of etherification rate constant
Authors: Alipour Mojtaba , Mohajeri Afshan
Published: February 2012

This research extends our more recent work on the application of molecular electrostatic potential as an effective approach in describing the influence of substituent on etherification reaction rate constant of phenol derivatives. Here, in addition to electronic factor, the steric effects have also been considered for our purpose. To analyze steric effects on etherification rate constant, we use the novel energy partition scheme proposed recently by Liu [S. B. Liu,J. Chem. Phys. 2007,126, 244103], where the total electronic energy is decomposed into three independent components: steric, electrostatic, and fermionic quantum. In this scheme, the steric potential has also been introduced. We first derive a relationship on the basis of density functional theory to show that the etherification rate constant should be proportional to the electrostatic potential on the atomic sites. Then, a bilinear function of molecular electrostatic potential and steric energy or steric potential is proposed for estimation of etherification reaction rate constants. Taking the experimental kinetics data of 30 substituted phenols, the validity of the proposed approach has been verified in position and momentum spaces. It is worth noting that the remarkable good performance of the momentum densities, which for the first time used in calculations of steric energy for a reaction, has been observed. Finally, using the relationship between new energy partition scheme and information theory, applicability of the Shannon entropy as one of the information theoretic measures is also tested for our goal and considerable results were obtained. Copyright © 2012 John Wiley & Sons, Ltd.
The effect of oxygen flow rates on magnetic and high‐frequency characteristics of Fe‐Hf‐O films
Authors: Wang Zong‐Shenq , Lai Yuan‐Tai , Duh Jenq‐Gong
Published: February 2012

This study aimed to investigate the influence of oxygen flow rate on magnetic and high‐frequency properties of as‐deposited FeHfO thin films, which were fabricated by DC reactive magnetron sputtering in an Ar + O2 atmosphere. These films exhibited mixed phases of α‐Fe nanograins and amorphous HfO2 phase, showing nanocrystalline structure and soft magnetic properties. The dispersion character of FeHfO films changed from relaxation‐type to resonance‐type when the oxygen flow rate varied from 1.0 to 1.2 sccm. Furthermore, the Fe58.8Hf13.1O28.1 film with the optimum O2 flow rate of 1.2 sccm exhibited high saturation magnetization of 10.6 kG, a high resistivity of 258 µΩ cm, a real component of permeability (µ′) of 250 up to 1 GHz and a high ferromagnetic resonance frequency of 2.5 GHz. It is expected that this film should be promising for practical applications as a high‐frequency ferromagnetic material.
Oxygen‐deficient ordered phases of ultrathin BaTiO3 films on Pt(111)
Authors: Förster Stefan , Meinel Klaus , Schindler Karl‐Michael , Widdra Wolf
Published: February 2012

The restructuring of epitaxial ultrathin BaTiO3 films on a Pt(111) substrate upon high‐temperature treatment has been studied by scanning tunneling microscopy, low‐energy electron diffraction, and XPS. Upon annealing ultrathin BaTiO3 films up to 4 monolayer equivalents in thickness at 1150 K in vacuum, BaTiO3 forms three‐dimensional islands surrounded by bare Pt. Annealing at 1250 K induces a two‐dimensional rewetting layer, which spreads around the three‐dimensional BaTiO3 islands. This rewetting layer consists of oxygen‐deficient BaTiO3. Within the rewetting layer, several long‐range ordered structures coexist. Their lattice constants vary between 11 and 46 Å. These rewetting structures are derived from a slightly modified BaTiO3(100) layer, which is stabilized by one direction of the Pt(111) lattice. The rewetting layer formation can be reversed by annealing in oxygen. Copyright © 2012 John Wiley & Sons, Ltd.
An XPS analysis of the oxide surface layers formed on a friction stir processed magnesium alloy
Authors: Cristóbal M. J. , Gesto D. , Miniño P. , Pena G. , Rey P. , Verdera D.
Published: February 2012

Friction stir processing (FSP) is a promising technique for improving plasticity of magnesium alloys through the homogenization and grain refinement of their structure. In this study, a magnesium alloy AZ31 has been processed by FSP to achieve an ultrafine grain size structure (700 nm), and the oxide films formed spontaneously on the surface of the FSP zone are compared with those on the unprocessed material. Chemical composition of the oxide films are analyzed by XPS.

The natural oxide films, close to 36 nm, can be described as a structure of (MgO)/Mg(OH)2 with the outermost surface mainly formed by Mg(OH)2/MgCO3. About 5–7 at.% of Al3+ is distributed through the oxide layer. Segregated zinc enrichment (Zn 2p3/2 at 1021.4 eV) at the interface oxide/metal is found. The FSP samples show higher carbonatation degree at the surface and a lower segregated zinc percentage at the interface oxide/metal. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of a Semiparametric Item Response Model
Authors: Peress Michael
Published: February 2012

We consider the identification of a semiparametric multidimensional fixed effects item response model. Item response models are typically estimated under parametric assumptions about the shape of the item characteristic curves (ICCs), and existing results suggest difficulties in recovering the distribution of individual characteristics under nonparametric assumptions. We show that if the shape of the ICCs are unrestricted, but the shape is common across individuals and items, the individual characteristics are identified. If the shape of the ICCs are allowed to differ over items, the individual characteristics are identified in the multidimensional linear compensatory case but only identified up to a monotonic transformation in the unidimensional case. Our results suggest the development of two new semiparametric estimators for the item response model.
Characterization of Iranian Virgin Olive Oil from the Roodbar Region: A Study on Zard, Mari and Phishomi
Authors: Kharazi Sepideh Haghighat , Kenari Reza Esmaeilzadeh , Amiri Zeinab Raftani , Azizkhani Maryam
Published: February 2012

The aim of this study is to describe the physicochemical properties of Iranian virgin olive oil (Zard, Mari and Phishomi) cultivated in Roodbar, Gilan. There were statistically significant differences for most of the parameters (P < 0.05). The acidity and peroxide value were in the limit established for classification as extra virgin olive oil. The oil of Zard had the highest amount of monounsaturated fatty acids followed by Mari and Phishomi oils. Mari oil proved to have the minimum value of polyunsaturated fatty acids, and the highest amount of phenolic compounds and oxidative stability. The oil of Phishomi had the maximum amount of chlorophylls and carotenoids and therefore it had the highest color index. There were no significant differences between the cultivars regarding the refractive index (1.469 at 20 °C for all three cultivars). According to the high content of monounsaturated fatty acids, the lowest amounts of polyunsaturated fatty acids and the highest amounts of phenolic compounds as well as the results of a Rancimat assay, it seems that the quality of the oil of Mari cultivar is better than Zard and Phishomi oils and is also more stable against oxidation.
Wood Adhesives Based on Alkaline Extracts from Wastewater Biosolids and Mustard Protein
Authors: García‐Becerra Flor Y. , Acosta Edgar J. , Grant Allen D.
Published: February 2012

This work reports on the dry adhesion strength of wood adhesives formulated with fractions of an alkaline extract obtained from wastewater activated sludge, a renewable and abundant resource. The extract was fractionated and desalted using ultrafiltration techniques. The effect of molecular weight and composition (protein and carbohydrate content) on the extract's adhesion strength was assessed, as well as the effect of crosslinking using glutaraldehyde. The dry adhesion strength of adhesives formulated with soluble mustard seed protein isolate, a protein‐rich alkaline extract, is also reported. In the presence of glutaraldehyde, an extract fraction with high protein content and low salt and hydroxide content showed adhesion strength close to that of the mustard protein adhesive and a commercial wood adhesive. It was further determined that the adhesion strength of the extract and its fractions was strongly correlated with their protein content.
Evaluation of Agronomic and Seed Characteristics in Elevated Oleic Acid Soybean Lines in the South‐Eastern US
Authors: Fallen Benjamin D. , Rainey Katy , Sams Carl E. , Kopsell Dean A. , Pantalone Vincent R.
Published: February 2012

Increasing oleic acid, a monounsaturated fatty acid, is reported to strike the best balance between cold flow properties and oxidative stability in soybean seed oil to enhance biodiesel and produce a better burning fuel. In addition, it is important that elevated oleic acid soybeans have the agronomic traits of local cultivars and maintain oleic acid stability across environments. Research was conducted in 2007–2008 to evaluate six Roundup Ready® soybean recombinant inbred lines exhibiting enhanced levels of oleic acid. The six elevated oleic lines averaged a 55% increase in oleic acid and a 43% decrease in linolenic acid over the two commercial cultivars (AG3906 and AG4103). Some elevated oleic acid genotypes fulfilled the linear regression definition of a stable genotype. TN03‐93RR was the best genotype because of its oleic acid content (397 g kg−1) and desirable regression estimates for stability. Iodine value (IV), peroxide value (PV), and induction period (IP) were used to evaluate the fuel properties of the two lines with the highest oleic acid content and the two commercial cultivars. The elevated oleic acid lines had significantly better IP, PV and IV for better biodiesel properties and oxidative stability than the two commercial cultivars.
Evolving concepts on the age‐related changes in “muscle quality”
Authors: Russ David W. , Gregg-Cornell Kimberly , Conaway Matthew J. , Clark Brian C.
Published: February 2012

The deterioration of skeletal muscle with advancing age has long been anecdotally recognized and has been of scientific interest for more than 150 years. Over the past several decades, the scientific and medical communities have recognized that skeletal muscle dysfunction (e.g., muscle weakness, poor muscle coordination, etc.) is a debilitating and life‐threatening condition in the elderly. For example, the age‐associated loss of muscle strength is highly associated with both mortality and physical disability. It is well‐accepted that voluntary muscle force production is not solely dependent upon muscle size, but rather results from a combination of neurologic and skeletal muscle factors, and that biologic properties of both of these systems are altered with aging. Accordingly, numerous scientists and clinicians have used the term “muscle quality” to describe the relationship between voluntary muscle strength and muscle size. In this review article, we discuss the age‐associated changes in the neuromuscular system—starting at the level of the brain and proceeding down to the subcellular level of individual muscle fibers—that are potentially influential in the etiology of dynapenia (age‐related loss of muscle strength and power).
Generically split projective homogeneous varieties. II
Authors: Petrov Victor , Semenov Nikita
Published: February 2012

This article gives a complete classification of generically split projective homogeneous varieties. This project was begun in our previous article [PS10], but here we remove all restrictions on the characteristic of the base field, give a new uniform proof that works in all cases and in particular includes the case PGO2n+ which was missing in [PS10].
Three-dimensional river bed forms
Authors: Colombini M. , Stocchino A.
Published: February 2012

The linear stability of a uniform flow in an infinitely wide erodible channel is investigated with respect to disturbances of the bed that are periodic in both the transverse and the longitudinal directions. A rotational flow and sediment transport model, originally developed to study the formation of two-dimensional dunes and antidunes, is straightforwardly extended to cover variations in the lateral direction. Sediment is assumed to be transported as bed load, disregarding the role of suspension. Following a standard linearization procedure, a dispersion relationship is obtained that expresses the growth rate and the celerity of the sand wave as a function of the streamwise and spanwise wavenumbers and of the relevant flow and sediment parameters. Regions of instabilities in the space of the parameters are found, which can be associated with bed forms of different kinds, spanning from dunes and antidunes to alternate bars. Therefore, the present theory allows for a unified view of the formation of two- and three-dimensional bed forms in rivers in terms of the relevant flow and sediment parameters.
FINITELY GENERATED δ-SUPPLEMENTED MODULES ARE AMPLY δ-SUPPLEMENTED
Authors: TRIBAK RACHID
Published: February 2012

Let R be a commutative ring. It is shown that if an R-module M is a sum of δ-local submodules and a semisimple projective submodule, then every finitely generated submodule of M is δ-supplemented. From this result, we conclude that finitely generated δ-supplemented modules over commutative rings are amply δ-supplemented.
A MINIMUM DEGREE CONDITION FOR FRACTIONAL ID-[a,b]-FACTOR-CRITICAL GRAPHS
Authors: ZHOU SIZHONG , SUN ZHIREN , LIU HONGXIA
Published: February 2012

Let G be a graph of order n, and let a and b be two integers with 1≤a≤b. Let h:E(G)→[0,1] be a function. If a≤∑ e∋xh(e)≤b holds for any x∈V (G), then we call G[Fh] a fractional [a,b] -factor of G with indicator function h, where Fh ={e∈E(G):h(e)>0}. A graph G is fractional independent-set-deletable [a,b] -factor-critical (in short, fractional ID-[a,b] -factor-critical) if G−I has a fractional [a,b] -factor for every independent set I of G. In this paper, it is proved that if n≥((a+2b)(a+b−2)+1 )/b and δ(G)≥((a+b)n )/(a+2b ) , then G is fractional ID-[a,b] -factor-critical. This result is best possible in some sense, and it is an extension of Chang, Liu and Zhu’s previous result.
Effects of a high-fat diet and bamboo extract supplement on anxiety- and depression-like neurobehaviours in mice
Authors: Del Rosario Adeline , McDermott Mindy M. , Panee Jun
Published: February 2012

High-fat diet is a major causative factor of overweight and obesity, which are associated with an increased risk of neuropsychiatric diseases, such as anxiety and depression. In the present study, we investigated the protective effects of bamboo extract (BEX) on anxiety- and depression-like neurobehaviours in mice treated with a high-fat diet. Male mice with CD-1 genetic background were treated for 2 months with either a standard or a high-fat diet (10 or 45 % energy from fat, respectively), with or without the BEX supplement (11 g dry mass per 17 MJ). The anxiety levels of mice were evaluated using open-field and hole-board tests, and depression was measured using the force-swimming test. The anxiety responses of the animals were found significantly increased after the high-fat diet treatment, and this elevation was effectively abolished by the BEX supplement. The high-fat diet seemed to have an anti-depressive effect in mice at the tested time point, but the effect of the BEX supplement on the depression level of the animals was not conclusive. The high-fat diet significantly decreased total glutathione content in the blood while the BEX supplement increased glutathione oxidation. In summary, the present study shows that decreased total glutathione concentration in the blood co-occurred with a high-fat treatment, high anxiety level and low depression level in mice, and when supplemented in a high-fat diet, BEX had an anxiolytic effect in mice.
A new magnetic resonance imaging scoring system for perilymphatic space appearance after intratympanic gadolinium injection, and its clinical application
Authors: Fang Z-M , Chen X , Gu X , Liu Y , Zhang R , Cao D-R , He H-G
Published: February 2012

Objective:

To establish a new magnetic resonance imaging scoring system for diagnosing endolymphatic hydrops.

Patients and methods:

A total of 214 ears of 107 patients were categorised into five groups: no symptoms, Ménière's disease, sudden deafness, delayed endolymphatic hydrops and other ear disorders. Gadolinium distribution within the labyrinth was scored separately and quantitatively by two radiologists. Multiple independent-sample non-parametric tests, Bayesian discriminant analysis, multivariate logistic regression and receiver operating characteristic curve analyses were performed.

Results:

The derived scoring model was highly accurate for diagnosing Ménière's disease and delayed endolymphatic hydrops. Two magnetic resonance imaging scoring methods for the perilymphatic space were proposed for the diagnosis of endolymphatic hydrops: a pre-1 value (a new variable that predicts individual probability) of more than 0.3982299, or a sum of all labyrinth component scores of less than 14.5.

Conclusion:

A convenient method is proposed which offers reliable radiological diagnostic criteria for Ménière's disease and delayed endolymphatic hydrops.
Controlled ionization-induced injection by tailoring the gas-density profile in laser wakefield acceleration
Authors: ZENG MING , HAFZ NASR A. M. , NAKAJIMA KAZUHISA , CHEN LI-MING , LU WEI , MORI WARREN B. , SHENG ZHENG-MING , ZHANG JIE
Published: February 2012

Ionization-induced injection into a laser-driven wakefield is studied using 2½D OSIRIS simulations. A laser propagates into a gas mixture of 99.5% helium and 0.5% nitrogen with gas density of each rising linearly from 0 to a peak, after which these remain constant. Simulations show that the process can be controlled by varying the scale length of an up-ramp, the laser intensity, and the maximum plasma density. The injection process is controlled by the bubble radius decreasing as laser propagates up the density gradient and laser self-focusing in the flat-top region. A beam with a central energy of 350 MeV and an energy spread (FWHM) of 1.62% was obtained for an up-ramp length of 135 μm, a normalized vector potential of 2, and a density of 7 × 1018cm−3 (assuming a 0.8 μm wavelength laser).
Trypanosoma cruziheparin-binding proteins mediate the adherence of epimastigotes to the midgut epithelial cells ofRhodnius prolixus
Authors: OLIVEIRA F. O. R. , ALVES C. R. , SOUZA-SILVA F. , CALVET C. M. , CÔRTES L. M. C. , GONZALEZ M. S. , TOMA L. , BOUÇAS R. I. , NADER H. B. , PEREIRA M. C. S.
Published: February 2012

Heparin-binding proteins (HBPs) have been demonstrated in both infective forms ofTrypanosoma cruziand are involved in the recognition and invasion of mammalian cells. In this study, we evaluated the potential biological function of these proteins during the parasite-vector interaction. HBPs, with molecular masses of 65·8 kDa and 59 kDa, were isolated from epimastigotes by heparin affinity chromatography and identified by biotin-conjugated sulfated glycosaminoglycans (GAGs). Surface plasmon resonance biosensor analysis demonstrated stable receptor-ligand binding based on the association and dissociation values. Pre-incubation of epimastigotes with GAGs led to an inhibition of parasite binding to immobilized heparin. Competition assays were performed to evaluate the role of the HBP-GAG interaction in the recognition and adhesion of epimastigotes to midgut epithelial cells ofRhodnius prolixus.Epithelial cells pre-incubated with HBPs yielded a 3·8-fold inhibition in the adhesion of epimastigotes. The pre-treatment of epimastigotes with heparin, heparan sulfate and chondroitin sulfate significantly inhibited parasite adhesion to midgut epithelial cells, which was confirmed by scanning electron microscopy. We provide evidence that heparin-binding proteins are found on the surface ofT. cruziepimastigotes and demonstrate their key role in the recognition of sulfated GAGs on the surface of midgut epithelial cells of the insect vector.
Poisson approximation for the number of visits to balls in non-uniformly hyperbolic dynamical systems
Authors: CHAZOTTES J.-R. , COLLET P.
Published: February 2012

We study the number of visits to balls Br(x), up to time t/μ(Br(x)), for a class of non-uniformly hyperbolic dynamical systems, where μ is the Sinai–Ruelle–Bowen measure. Outside a set of ‘bad’ centers x, we prove that this number is approximately Poissonnian with a controlled error term. In particular, when r→0, we get convergence to the Poisson law for a set of centers of μ-measure one. Our theorem applies for instance to the Hénon attractor and, more generally, to systems modelled by a Young tower whose return-time function has an exponential tail and with one-dimensional unstable manifolds. Along the way, we prove an abstract Poisson approximation result of independent interest.
On Finsler surfaces without conjugate points
Authors: GOMES JOSÉ BARBOSA , RUGGIERO RAFAEL O.
Published: February 2012

If (M,F) is a C4 compact Finsler surface of genus at least two without conjugate points, we show that the first integrals of the geodesic flow are constant. Using this fact, we show that if (M,F) is also of Landsberg type then (M,F) is Riemannian. The connection between the absence of conjugate points and the Riemannian character of the Finsler metric has some remarkable consequences concerning rigidity.
A reassessment of frequency and vocabulary size in L2 vocabulary teaching
Authors: Schmitt Norbert , Schmitt Diane
Published: February 2012

The high-frequency vocabulary of English has traditionally been thought to consist of the 2,000 most frequent word families, and low-frequency vocabulary as that beyond the 10,000 frequency level. This paper argues that these boundaries should be reassessed on pedagogic grounds. Based on a number of perspectives (including frequency and acquisition studies, the amount of vocabulary necessary for English usage, the range of graded readers, and dictionary defining vocabulary), we argue that high-frequency English vocabulary should include the most frequent 3,000 word families. We also propose that the low-frequency vocabulary boundary should be lowered to the 9,000 level, on the basis that 8–9,000 word families are sufficient to provide the lexical resources necessary to be able to read a wide range of authentic texts (Nation 2006). We label the vocabulary between high-frequency (3,000) and low-frequency (9,000+) as mid-frequency vocabulary. We illustrate the necessity of mid-frequency vocabulary for proficient language use, and make some initial suggestions for research addressing the pedagogical challenge raised by mid-frequency vocabulary.
How to analyse seed germination data using statistical time-to-event analysis: non-parametric and semi-parametric methods
Authors: McNair James N. , Sunkara Anusha , Frobish Daniel
Published: February 2012

Seed germination experiments are conducted in a wide variety of biological disciplines. Numerous methods of analysing the resulting data have been proposed, most of which fall into three classes: intuition-based germination indexes, classical non-linear regression analysis and time-to-event analysis (also known as survival analysis, failure-time analysis and reliability analysis). This paper briefly reviews all three of these classes, and argues that time-to-event analysis has important advantages over the other methods but has been underutilized to date. It also reviews in detail the types of time-to-event analysis that are most useful in analysing seed germination data with standard statistical software. These include non-parametric methods (life-table and Kaplan–Meier estimators, and various methods for comparing two or more groups of seeds) and semi-parametric methods (Cox proportional hazards model, which permits inclusion of categorical and quantitative covariates, and fixed and random effects). Each method is illustrated by applying it to a set of real germination data. Sample code for conducting these analyses with two standard statistical programs is also provided in the supplementary material available online (athttp://journals.cambridge.org/). The methods of time-to-event analysis reviewed here can be applied to many other types of biological data, such as seedling emergence times, flowering times, development times for eggs or embryos, and organism lifetimes.
Influence of irrigation schemes used in regional climate models on evapotranspiration estimation: Results and comparative studies from California's Central Valley agricultural regions
Authors: Sorooshian Soroosh , Li Jialun , Hsu Kuo‐lin , Gao Xiaogang
Published: February 2012

The agricultural sector is the largest consumer of water in California. The impacts of irrigation on local and/or regional weather and climate have been studied and reported in recent literature. However, because of the lack of observations and realistic irrigation schemes employed in the numerical models, most previous studies fall in the category of sensitivity tests, focusing on temperature variations. The results being reported in this paper are obtained by incorporating into the MM5/Noah land surface model an irrigation method practiced in California's farming sector. The proposed irrigation scheme is based on the principle that irrigation occurs when available soil‐water content is less than the maximum allowable water depletion (SWm), which depends on both soil type and crop type. The study's focus was to evaluate the impact of a more realistic irrigation scheme on surface fluxes, especially evapotranspiration (ET). It is demonstrated that more accurate amounts and patterns of ET in the Central Valley are realized, as compared to ET estimates (in terms of amounts and spatial distribution) obtained from remotely sensed observation as well as in situ ground data. It is demonstrated that significant discrepancies of ET estimates between different irrigation schemes used in regional hydroclimate modeling exist, which may result in erroneous conclusions about the impact of irrigation on regional water balance, especially over and near agricultural areas.
Identification and analysis of atmospheric states and associated cloud properties for Darwin, Australia
Authors: Evans S. M. , Marchand R. T. , Ackerman T. P. , Beagley N.
Published: February 2012

An iterative automated classification technique that combines European Centre for Medium‐Range Weather Forecasts analysis data and vertically pointing millimeter wavelength cloud radar observations is used to identify commonly occurring atmospheric patterns or states around Darwin, Australia. The technique defines the atmospheric states by large‐scale, synoptic variables such that, once defined, these states will be suitable to composite climate model output. Radar observations of clouds are used to test the statistical significance of each state and prompt the automated refinement of the states until each state produces a statistically stable and unique hydrometeor occurrence profile. The technique identifies eight atmospheric states: two monsoon states, two transition season states, and four dry season states. The two monsoon states can be identified as the active monsoon and the break monsoon. Among the dry season states, periods of isolated and suppressed convection can be identified. We use these states as the basis for compositing hydrometeor occurrence, precipitation rate, outgoing longwave radiation, and Madden‐Julian Oscillation phase to further understand the meteorology of each state.
Temporal variability of hydroclimatic extremes in the Blue Nile basin
Authors: Taye Meron Teferi , Willems Patrick
Published: February 2012

This paper examines the long‐term historical changes in frequency and amplitude of hydroclimatic extremes in the Blue Nile basin using data from the second half of 20th century. The temporal variability of basin‐wide rainfall extremes and river flow extremes from four gauging stations was investigated under the hypothesis of no trend and no persistence in time. On the basis of a quantile anomaly analysis method, decadal variations in extreme daily, monthly, and annual quantiles were studied, and the periods of statistical significance were identified. The analysis showed that high and low river flows and rainfall depths do not vary in time in a fully random way but show a particular variation pattern. Their extremes show significant decadal variations. The 1980s had statistically significant negative anomalies in extremes in comparison with the long‐term reference period of 1964–2009, while the 1960s–1970s and the 1990s–2000s had positive anomalies, although less significant. There is neither consistent increasing nor decreasing trend in rainfall and flow extremes of recent years. Therefore, anticipated trends due to global warming could not be identified. Conversely, low‐flow extremes show an increasing trend during the last decade, which could be related to the effect of water regulation works at the outlet of Lake Tana. Moreover, similar patterns and statistically significant correlations were found between climatic indices representing the Pacific and Atlantic Oceans and the Blue Nile rainfall and flow extremes. Changes that occur on the Pacific Ocean appear to be a main driver for the decadal oscillations in climate and related high and low Blue Nile water availability for Ethiopia, Sudan, and Egypt.
Identification of a molecular component of the mitochondrial acetyltransferase programme: a novel role for GCN5L1
Authors: Scott Iain , Webster Bradley R. , Li Jian H. , Sack Michael N.
Published: February 2012

SIRT3 (sirtuin 3) modulates respiration via the deacetylation of lysine residues in electron transport chain proteins. Whether mitochondrial protein acetylation is controlled by a counter-regulatory program has remained elusive. In the present study we identify an essential component of this previously undefined mitochondrial acetyltransferase system. We show that GCN5L1 [GCN5 (general control of amino acid synthesis 5)-like 1; also known as Bloc1s1] counters the acetylation and respiratory effects of SIRT3. GCN5L1 is mitochondrial-enriched and displays significant homology with a prokaryotic acetyltransferase. Genetic knockdown of GCN5L1 blunts mitochondrial protein acetylation, and its reconstitution in intact mitochondria restores protein acetylation. GCN5L1 interacts with and promotes acetylation of SIRT3 respiratory chain targets and reverses global SIRT3 effects on mitochondrial protein acetylation, respiration and bioenergetics. The results of the present study identify GCN5L1 as a critical prokaryote-derived component of the mitochondrial acetyltransferase programme.
Restoration of adipose function in obese glucose-tolerant men following pioglitazone treatment is associated with CCAAT enhancer-binding protein β up-regulation
Authors: Powell Lesley A. , Crowe Paul , Kankara Chenchi , McPeake Jennifer , McCance David R. , Young Ian S. , Trimble Elisabeth R. , McGinty Ann
Published: February 2012

Obese AT (adipose tissue) exhibits increased macrophage number. Pro-inflammatory CD16+ peripheral monocyte numbers are also reported to increase with obesity. The present study was undertaken to simultaneously investigate obesity-associated changes in CD16+ monocytes and ATMs (AT macrophages). In addition, a pilot randomized placebo controlled trial using the PPAR (peroxisome-proliferator-activated receptor) agonists, pioglitazone and fenofibrate was performed to determine their effects on CD14+/CD16+ monocytes, ATM and cardiometabolic and adipose dysfunction indices. Obese glucose-tolerant men (n=28) were randomized to placebo, pioglitazone (30 mg/day) and fenofibrate (160 mg/day) for 12 weeks. A blood sample was taken to assess levels of serum inflammatory markers and circulating CD14+/CD16+ monocyte levels via flow cytometry. A subcutaneous AT biopsy was performed to determine adipocyte cell surface and ATM number, the latter was determined via assessment of CD68 expression by IHC (immunohistochemistry) and real-time PCR. Subcutaneous AT mRNA expression of CEBPβ (CCAAT enhancer-binding protein β), SREBP1c (sterol-regulatory-element-binding protein 1c), PPARγ2, IRS-1 (insulin receptor substrate-1), GLUT4 (glucose transporter type 4) and TNFα (tumour necrosis factor α) were also assessed. Comparisons were made between obese and lean controls (n=16) at baseline, and pre- and post-PPAR agonist treatment. Obese individuals had significantly increased adipocyte cell surface, percentage CD14+/CD16+ monocyte numbers and ATM number (all P=0.0001). Additionally, serum TNF-α levels were significantly elevated (P=0.017) and adiponectin levels reduced (total: P=0.0001; high: P=0.022) with obesity. ATM number and percentage of CD14+/CD16+ monocytes correlated significantly (P=0.05). Pioglitazone improved adiponectin levels significantly (P=0.0001), and resulted in the further significant enlargement of adipocytes (P=0.05), without effect on the percentage CD14+/CD16+ or ATM number. Pioglitazone treatment also significantly increased subcutaneous AT expression of CEBPβ mRNA. The finding that improvements in obesity-associated insulin resistance following pioglitazone were associated with increased adipocyte cell surface and systemic adiponectin levels, supports the centrality of AT to the cardiometabolic derangement underlying the development of T2D (Type 2 diabetes) and CVD (cardiovascular disease).
Upgrade of the resonance ionization laser ion source at ISOLDE on-line isotope separation facility: New lasers and new ion beams
Authors: Fedosseev V. N. , Berg L.-E. , Fedorov D. V. , Fink D. , Launila O. J. , Losito R. , Marsh B. A. , Rossel R. E. , Rothe S. , Seliverstov M. D. , Sjödin A. M. , Wendt K. D. A.
Published: February 2012

The resonance ionization laser ion source (RILIS) produces beams for the majority of experiments at the ISOLDE on-line isotope separator. A substantial improvement in RILIS performance has been achieved through a series of upgrade steps: replacement of the copper vapor lasers by a Nd:YAG laser; replacement of the old homemade dye lasers by new commercial dye lasers; installation of a complementary Ti:Sapphire laser system. The combined dye and Ti:Sapphire laser system with harmonics is capable of generating beams at any wavelength in the range of 210–950 nm. In total, isotopes of 31 different elements have been selectively laser-ionized and separated at ISOLDE, including recently developed beams of samarium, praseodymium, polonium, and astatine.
Simulation of H− ion source extraction systems for the Spallation Neutron Source with Ion Beam Simulator
Authors: Kalvas T. , Welton R. F. , Tarvainen O. , Han B. X. , Stockli M. P.
Published: February 2012

A three-dimensional ion optical code IBSimu, which is being developed at the University of Jyväskylä, features positive and negative ion plasma extraction models and self-consistent space charge calculation. The code has been utilized for modeling the existing extraction system of the H− ion source of the Spallation Neutron Source. Simulation results are in good agreement with experimental data. A high-current extraction system with downstream electron dumping at intermediate energy has been designed. According to the simulations it provides lower emittance compared to the baseline system at H− currents exceeding 40 mA. A magnetic low energy beam transport section consisting of two solenoids has been designed to transport the beam from the alternative electrostatic extraction systems to the radio frequency quadrupole.
Phase instability of magnetic ground state in antiperovskite Mn3ZnN: Giant magnetovolume effects related to magnetic structure
Authors: Hamada T. , Takenaka K.
Published: February 2012

We verified the intimate relation between magnetism and volume in Mn3ZnN. The sample sintered at 900 °C is characterized by the Γ5g triangular antiferromagnetic (AF) state with larger volume below 170 K. However, for the sample sintered at 700 °C, the re-entrant phase transition appears at 80 K and the ground state is a different AF state with smaller volume. These results indicate that the ground state of Mn3ZnN is sensitive to the disorder in the N site and that the magnetic structure drastically alters magnetovolume effects. More detailed consideration is necessary beyond the conventional scheme, which incorporates only the amplitude of the magnetic moment.
Ab initio calculation of the local magnetic moment in titanium doped zinc oxide with a corrected-band-gap scheme
Authors: Shao Bin , Liu Hong , Wu Jian , Zuo Xu
Published: February 2012

The local magnetic moment of Ti:ZnO is calculated from first principles by using the corrected-band-gap scheme (CBGS). The result shows that the system is magnetic with the magnetization of 0.699 μB per dopant. The origin of the local magnetic moment is considered to be the impurity band partially occupied by the donor electrons in the conduction band. Further, the impacts of applying Hubbard U to Ti-d orbital on the magnetic moment have been investigated.
Direct calorimetric measurements of isothermal entropy change on single crystal W-type hexaferrites at the spin reorientation transition
Authors: LoBue M. , Loyau V. , Mazaleyrat F. , Pasko A. , Basso V. , Kuepferling M. , Sasso C. P.
Published: February 2012

We report on the magnetic field induced isothermal entropy change, Δs(Ha, T), of W-type ferrite with CoZn substitution. Entropy measurements are performed by direct calorimetry. Single crystals of the composition BaCo0.62Zn1.38Fe16O27, prepared by the flux method, are measured at different fixed temperatures under an applied field perpendicular and parallel to the c axis. At 296 K one deduces a value of K1 = 8.7 × 104  J m−3 for the first anisotropy constant, which is in good agreement with the literature. The spin reorientation transition temperature is estimated to take place between 200 and 220 K.
Berry phase from a randomly fluctuating magnetic field
Authors: Skomski R.
Published: February 2012

The quantum-mechanical Berry phase due to a randomly fluctuating magnetic field is calculated by exploiting an analogous random-walk problem in polymer physics. The phase depends on the time correlations of the magnetic field, despite the adiabatic nature of the Berry phase. A probability distribution for the phase is obtained, and how this phase could affect the magnetotransport in granular magnetic nanostructures is briefly discussed.
Magnetic characteristics of a new cubic defect spinel Li0.5Mg0.5MnO3
Authors: Singh V. , Seehra M. S. , Manivannan A. , Kumta P. N.
Published: February 2012

Magnetic properties of Li0.5Mg0.5MnO3−δ nanoparticles (size ≃ 20 nm) synthesized by the Pechini method are investigated using temperature dependence of its magnetization (M) and electron magnetic resonance (EMR) spectra at 9.286 GHz. Analysis of the x-ray diffraction spectra yields its structure to be a cubic defect spinel with the formula 4(Li0.5Mg0.5MnO2.75) = 3{[Li2/3Mg1/3][Mn4/3Mg1/3□1/3]O11/3]} so that Mn occupies the octahedral B-sites only. The data of M versus T yields a blocking temperature TB ≃ 9 K above which the Curie–Weiss law variation with θ = 13 K and μ = 3.96μB characteristic of Mn4+ ions is established. For T < 9 K, temperature dependent coercivity and remanence are observed. The observed temperature dependence of the EMR parameters (linewidth ΔH, resonance field Hr, and intensity Io) for T < 30 K is interpreted in terms of TB (EMR) ≃ 30 K. Formation of ferromagnetic Mn4+ clusters, resulting from the co-presence of non-magnetic Mg2+ and vacancies on the B-sites, is inferred.