bluuebunny/crossref_metadata_2025 huggingface dataset:
x-T phase diagram of La-substituted BiFeO3-PbTiO3
Authors: Mishra K. K. , Sarguna R. M. , Khan Shabana , Arora A. K.
Published: August 2011

Single-phase polycrystalline powders of 0.5(Bi1-xLax)FeO3-0.5PbTiO3 solid-solution were synthesized for x ≤ 0.3 using solid-state reaction method. The mixed crystals exhibit a tetragonal structure at ambient and the c/a ratio decreases with x. In-situ X-ray diffraction measurements at elevated temperatures show a structural transition to a cubic phase. The transition temperatures have been obtained for different x and a x-T phase diagram has been proposed.
Stress exposure in intrauterine life is associated with shorter telomere length in young adulthood
Authors: Entringer Sonja , Epel Elissa S. , Kumsta Robert , Lin Jue , Hellhammer Dirk H. , Blackburn Elizabeth H. , Wüst Stefan , Wadhwa Pathik D.
Published: August 2011

Leukocyte telomere length (LTL) is a predictor of age-related disease onset and mortality. The association in adults of psychosocial stress or stress biomarkers with LTL suggests telomere biology may represent a possible underlying mechanism linking stress and health outcomes. It is, however, unknown whether stress exposure in intrauterine life can produce variations in LTL, thereby potentially setting up a long-term trajectory for disease susceptibility. We, therefore, as a first step, tested the hypothesis that stress exposure during intrauterine life is associated with shorter telomeres in adult life after accounting for the effects of other factors on LTL. LTL was assessed in 94 healthy young adults. Forty-five subjects were offspring of mothers who had experienced a severe stressor in the index pregnancy (prenatal stress group; PSG), and 49 subjects were offspring of mothers who had a healthy, uneventful index pregnancy (comparison group; CG). Prenatal stress exposure was a significant predictor of subsequent adult telomere length in the offspring (178-bp difference between prenatal stress and CG;
d
= 0.41 SD units;
P
< 0.05). The effect was substantially unchanged after adjusting for potential confounders (subject characteristics, birth weight percentile, and early-life and concurrent stress level), and was more pronounced in women (295-bp difference;
d
= 0.68 SD units;
P
< 0.01). To the best of our knowledge, this study provides the first evidence in humans of an association between prenatal stress exposure and subsequent shorter telomere length. This observation may help shed light on an important biological pathway underlying the developmental origins of adult health and disease risk.
Immunoglobulin E‐mediated hypersensitivity to amoxicillin: in vivo and in vitro comparative studies between an injectable therapeutic compound and a new commercial compound
Authors: Torres M. J. , Romano A. , Blanca‐Lopez N. , Doña I. , Canto G. , Ariza A. , Aranda A. , Montañez M. I. , Mayorga C. , Blanca M.
Published: August 2011

Background Skin testing with amoxicillin (AX) is necessary to diagnose immediate hypersensitivity reactions to this β‐lactam. A commercial AX (DIA‐AX) has recently become available for skin testing.

Objective The aim of this study was to compare DIA‐AX with the injectable form (INJ‐AX) in patients who have well‐demonstrated IgE‐mediated hypersensitivity to AX.

Methods Chemical characterization using high‐performance liquid chromatography of both DIA‐AX and INJ‐AX reagents was performed. Patients diagnosed with an immediate allergic reaction to AX and a positive skin test to INJ‐AX (N=55) were re‐evaluated within 6 months by performing skin testing with INJ‐AX and DIA‐AX. Basophil activation test (BAT) and Radioallergosorbent test (RAST) inhibition assay using both reagents were performed in a selected group of patients.

Results The chemical analysis indicated that both DIA‐AX and INJ‐AX contained an AX compound with a purity above 95%. In the re‐evaluation, 53 (96.4%) cases maintained skin test positivity to INJ‐AX and were also positive to DIA‐AX. Comparison of the papule area between the two reagents showed no significant differences between both reagents. BAT was performed in 30 samples and was positive to both compounds in 15 cases; no patient had a positive result to just one reagent. RAST inhibition studies using three individual cases and a pool of positive sera showed that the percentage inhibition detected with DIA‐AX and INJ‐AX was parallel and almost exactly the same.

Conclusions This study shows that DIA‐AX is equivalent to INJ‐AX in terms of skin test response, as well as with in vitro immunochemical and biological tests. DIA‐AX can therefore be used in the diagnosis of immediate hypersensitivity reactions.

Cite this as: M. J. Torres, A. Romano, N. Blanca‐Lopez, I. Doña, G. Canto, A. Ariza, A. Aranda, M. I. Montañez, C. Mayorga and M. Blanca, Clinical & Experimental Allergy, 2011 (41) 1595–1601.
An experimental test of the effect of signal size and performance capacity on dominance in the green anole lizard
Authors: Henningsen Justin P. , Irschick Duncan J.
Published: August 2011

1. Many animals use signals to resolve disputes over resources. Some signals act as reliable indicators of other traits, such as whole‐organism performance or body condition, which may also be important for resolving disputes. Because of the correlations inherent in reliable signals, it is challenging to determine which variables are directly relevant for resolving aggressive interactions.

2. We examined the relationships among dewlap size, bite force and condition, all traits that may be important to conflict resolution in male green anole lizards (Anolis carolinensis). Using a large sample of wild‐caught animals, we showed significant positive correlations between dewlap size and maximum bite force capacity, when each trait is corrected for its correlation with body size.

3. We tested the relative importance of each trait to the outcome of interactions in a subset of our sample. We staged dominance encounters between size‐matched male green anoles after surgically reducing the dewlap size of one competitor.

4. We show that reducing the size of the dewlap does not significantly change the outcome of staged interactions. Rather, males with higher values of bite force capacity were more likely to win fights. We hypothesize that during close‐proximity aggressive interactions, male green anoles use more direct means of assessing one another and that dewlap size functions as a signal of bite force primarily during long‐distance territorial displays. Body condition was correlated with bite force, but did not differ significantly between winners and losers.

5. Our results show how an experimental approach can decouple reliable signals from their correlated traits to test which factors influence male contest resolution.
Weak or absent evidence for the association of HLA‐DR antigens with risk of thyroid carcinoma: a meta‐analysis of observational studies
Authors: Kamdi A. S. , Kandavalli N. B. , Emusu D. , Jain N. , Mamtani M. , Porterfield J. R.
Published: August 2011

Inconsistent reports of associations between human leukocyte antigen (HLA)‐DR and thyroid cancers exist. We conducted a comprehensive search of the PubMed, Scopus and Web of Science databases. Using random‐effects modeling, subgroup analyses, meta‐regression and prediction interval (PI) estimation, we combined the existing evidence from 13 studies (977 cases of thyroid cancer and 3735 controls). Only HLA‐DR1 and HLA‐DR11 were significantly associated; however, the evidence for HLA‐DR11 came from only three studies while that for HLA‐DR1 had large between‐study heterogeneity. All the PIs estimated in the study straddled unity. Therefore, current evidence for the studied association is incomplete as well as uncertain. Attempts to include HLA‐DR typing as a prognostic or therapeutic marker may be premature at this time.
Looking back at the doctorate: A qualitative study of Jordanian graduates from PhD programs in the UK
Authors: Ali Zeilani Ruqayya S. , Al‐Nawafleh Ahmed H. , Evans Catrin
Published: August 2011

Many countries develop their nursing capacity by sending nurses overseas to gain their doctorates. There is a lack of research on their subsequent experience and career development. Focusing on the Jordanian and UK contexts, this qualitative study explored the doctoral and postdoctoral experience. Interviews were held with 16 PhD nursing graduates in Jordan. The participants had studied in 12 different universities in the UK and now worked as faculty members in seven Jordanian universities. The data were analyzed thematically. The participants reported that the most difficult task (but also the most significant achievement) was the transition to autonomous scholarship. They also described a profound personal transformation as a result of living in another country. However, very few of them could cite examples of how they were using their skills now to influence their current practice within their faculty roles. This suggests a possible under‐use of the skills, new perspectives, and enthusiasm that new doctoral graduates bring back home with them. Future research should focus on identifying ways to support and develop doctoral nursing graduates to maximize their potential on their return home.
All‐Hex Mesh Generation via Volumetric PolyCube Deformation
Authors: Gregson James , Sheffer Alla , Zhang Eugene
Published: August 2011

While hexahedral mesh elements are preferred by a variety of simulation techniques, constructing quality all‐hex meshes of general shapes remains a challenge. An attractive hex‐meshing approach, often referred to as sub‐mapping, uses a low distortion mapping between the input model and a PolyCube (a solid formed from a union of cubes), to transfer a regular hex grid from the PolyCube to the input model. Unfortunately, the construction of suitable PolyCubes and corresponding volumetric maps for arbitrary shapes remains an open problem. Our work introduces a new method for computing low‐distortion volumetric PolyCube deformations of general shapes and for subsequent all‐hex remeshing. For a given input model, our method simultaneously generates an appropriate PolyCube structure and mapping between the input model and the PolyCube. From these we automatically generate good quality all‐hex meshes of complex natural and man‐made shapes.
Skeleton computation of orthogonal polyhedra
Authors: Martinez J. , Vigo M. , Pla‐Garcia N.
Published: August 2011

Skeletons are powerful geometric abstractions that provide useful representations for a number of geometric operations. The straight skeleton has a lower combinatorial complexity compared with the medial axis. Moreover, while the medial axis of a polyhedron is composed of quadric surfaces the straight skeleton just consist of planar faces. Although there exist several methods to compute the straight skeleton of a polygon, the straight skeleton of polyhedra has been paid much less attention. We require to compute the skeleton of very large datasets storing orthogonal polyhedra. Furthermore, we need to treat geometric degeneracies that usually arise when dealing with orthogonal polyhedra. We present a new approach so as to robustly compute the straight skeleton of orthogonal polyhedra. We follow a geometric technique that works directly with the boundary of an orthogonal polyhedron. Our approach is output sensitive with respect to the number of vertices of the skeleton and solves geometric degeneracies. Unlike the existing straight skeleton algorithms that shrink the object boundary to obtain the skeleton, our algorithm relies on the plane sweep paradigm. The resulting skeleton is only composed of axis‐aligned and 45° rotated planar faces and edges.
STRUCTURAL CHANGE AND GROWTH IN CHINA UNDER ECONOMIC REFORMS: PATTERNS, CAUSES AND IMPLICATIONS
Authors: Jiang Yanqing
Published: August 2011

This paper investigates the patterns, causes, and implications of China's structural change and its contribution to China's regional growth. Among many other findings, our regression results show that conditional convergence exists across different regions in China. Regional structural change has a convergence effect and regional openness facilitates regional structural change. Structural shocks and structural transformation had the opposite effect on China's interregional convergence during the 1990s, though the combined effect of overall structural change is a convergence effect. We also find that Chinese regions rely more heavily on structural change for labor productivity growth as the economy evolves. In summary, the results of our empirical analysis support the hypothesis underlying the theoretical model of this paper.
An Explicit Link between Gaussian Fields and Gaussian Markov Random Fields: The Stochastic Partial Differential Equation Approach
Authors: Lindgren Finn , Rue Håvard , Lindström Johan
Published: August 2011

Continuously indexed Gaussian fields (GFs) are the most important ingredient in spatial statistical modelling and geostatistics. The specification through the covariance function gives an intuitive interpretation of the field properties. On the computational side, GFs are hampered with the big n problem, since the cost of factorizing dense matrices is cubic in the dimension. Although computational power today is at an all time high, this fact seems still to be a computational bottleneck in many applications. Along with GFs, there is the class of Gaussian Markov random fields (GMRFs) which are discretely indexed. The Markov property makes the precision matrix involved sparse, which enables the use of numerical algorithms for sparse matrices, that for fields in ℝ2 only use the square root of the time required by general algorithms. The specification of a GMRF is through its full conditional distributions but its marginal properties are not transparent in such a parameterization. We show that, using an approximate stochastic weak solution to (linear) stochastic partial differential equations, we can, for some GFs in the Matérn class, provide an explicit link, for any triangulation of ℝd, between GFs and GMRFs, formulated as a basis function representation. The consequence is that we can take the best from the two worlds and do the modelling by using GFs but do the computations by using GMRFs. Perhaps more importantly, our approach generalizes to other covariance functions generated by SPDEs, including oscillating and non-stationary GFs, as well as GFs on manifolds. We illustrate our approach by analysing global temperature data with a non-stationary model defined on a sphere.
Protein tyrosine phosphatase σ regulates the synapse number of zebrafish olfactory sensory neurons
Authors: Chen Xigui , Yoshida Tomoyuki , Sagara Hiroshi , Mikami Yoshinori , Mishina Masayoshi
Published: August 2011

J. Neurochem. (2011) 119, 532–543.

The formation and refinement of synaptic connections are key steps of neural development to establish elaborate brain networks. To investigate the functional role of protein tyrosine phosphatase (PTP) σ, we employed an olfactory sensory neuron (OSN)‐specific gene manipulation system in combination with in vivo imaging of transparent zebrafish embryos. Knockdown of PTPσ enhanced the accumulation of synaptic vesicles in the axon terminals of OSNs. The exaggerated accumulation of synaptic vesicles was restored to the normal level by the OSN‐specific expression of PTPσ, indicating that presynaptic PTPσ is responsible for the regulation of synaptic vesicle accumulation. Consistently, transient expression of a dominant‐negative form of PTPσ in OSNs enhanced the accumulation of synaptic vesicles. The exaggerated accumulation of synaptic vesicles was reproduced in transgenic zebrafish lines carrying an OSN‐specific expression vector of the dominant‐negative PTPσ. By electron microscopic analysis of the transgenic line, we found the significant increase of the number of OSN‐mitral cell synapses in the central zone of the olfactory bulb. The density of docked vesicles at the active zone was also increased significantly. Our results suggest that presynaptic PTPσ controls the number of OSN‐mitral cell synapses by suppressing their excessive increase.
A decision support methodology for increasing school efficiency in Bolivia's low‐income communities
Authors: de Figueiredo João Neiva , Marca Barrientos Miguel Angel
Published: August 2011

This paper presents a data envelopment analysis (DEA)‐based decision‐support methodology that has been implemented and is being used by a not‐for‐profit organization, Fe y Alegría, which runs 439 Bolivian schools reaching over 160,000 disadvantaged students in that poverty‐stricken Latin American nation. Bolivia is a poor country with the highest percentage of indigenous population and the lowest per capita income in South America and as such its inhabitants are in dire need of effective educational resources to help them out of poverty. The DEA‐based methodology described in this paper has offered an objective way to compare network schools among themselves and with out‐of‐network schools, providing a deeper understanding of school efficiency levels in the face of scarce resources, and allowing for sharing of best practices across the network. The paper introduces the educational environment in Bolivia, presents the DEA model, describes the decision support methodology, and provides two examples of its use. The first example compares Fe y Alegría secondary schools with out‐of‐network secondary schools using publicly available data, and the second compares Fe y Alegría secondary schools among themselves using a proprietary database. The paper also comments on lessons learned and the need for broad consensus‐building and organization‐wide buy‐in for successful adoption and maximum impact.
Dark bands on pyritic internal moulds of the Early Jurassic ammonites Oxynoticeras and Cheltonia from Gloucestershire, England: interpretation and significance to ammonite growth analysis
Authors: PAUL CHRISTOPHER R. C.
Published: August 2011

Abstract:  Thin, radiating, darker bands occur on pyritic internal moulds of the Early Jurassic ammonites Oxynoticeras and Cheltonia from Bishop’s Cleeve, Gloucestershire. They closely resemble true colour patterns preserved in Early Jurassic Calliphylloceras from Kutch, India, and false colour patterns reported in Carboniferous and Triassic ammonoids. Up to five dark bands occur within the body chamber, suggesting that they do not represent serially repeated anatomical structures, but the same feature repeatedly formed during growth. Dark bands are interpreted as traces of black bands deposited on the inside of the shell at the aperture during pauses in growth. The angles between dark bands and between septa correlate strongly in Cheltonia, suggesting that pauses in growth coincided with septal secretion during the chamber formation cycle. There are, however, no other indications that growth was episodic in either genus.
EFFECTS OF FARMING PRACTICES ON THE QUALITY OF ULTRA‐FROZEN MANDARIN JUICE
Authors: NAVARRO P. , MELENDEZ‐MARTINEZ A.J. , HEREDIA F. , GABALDON J.A. , PEREZ‐LOPEZ A.J.
Published: August 2011

The effects of the farming type (organic or conventional) and cyclodextrin addition on the quality (loss of ascorbic acid, carotenoids composition, color and antioxidant activity) of freshly squeezed, nonpasteurized, ultra‐frozen mandarin juices were studied during a shelf life of 145 days. The vitamin C content was reduced from 540 and 470 mg/L to 515 and 447 mg/L in organic and conventional juices, respectively. Carotenoids were stable during the storage time (decreases being in the range 5–10%), with β‐cryptoxanthin (7.21 ± 0.31 mg/L) being the most abundant compound, followed by lutein and zeaxanthin. The juices color was not affected by thermal treatment and these data were provided by both instrumental Commission internationale de l'éclairage L*, a*, b* data and the sensory studies conducted. The antioxidant activity was 0.04 and 0.06 mMT/mL, at day 0, for the organic and conventional juices; the losses during the storage were below 18%. The addition of cyclodextrins did not have any significant effect on the parameters under study. This study showed that the nutritional and organoleptic quality of ultra‐frozen juices is quite stable during the storage period.

PRACTICAL APPLICATIONS

The application of cyclodextrins in the food industry is very important as solubilizing agents, stabilizers and emulsifiers. The molecular encapsulation of lipophilic food ingredients with cyclodextrin improves the stability of flavors, vitamins, colorants and unsaturated fats, etc., both in physical and chemical sense leading to extended product shelf life, accelerated and long‐term storage stability.
Depth Cues Versus the Simplicity Principle in 3D Shape Perception
Authors: Li Yunfeng , Pizlo Zygmunt
Published: August 2011

Two experiments were performed to explore the mechanisms of human 3D shape perception. In Experiment 1, the subjects’ performance in a shape constancy task in the presence of several cues (edges, binocular disparity, shading and texture) was tested. The results show that edges and binocular disparity, but not shading or texture, are important in 3D shape perception. Experiment 2 tested the effect of several simplicity constraints, such as symmetry and planarity on subjects’ performance in a shape constancy task. The 3D shapes were represented by edges or vertices only. The results show that performance with or without binocular disparity is at chance level, unless the 3D shape is symmetric and/or its faces are planar. In both experiments, there was a correlation between the subjects’ performance with and without binocular disparity. Our study suggests that simplicity constraints, not depth cues, play the primary role in both monocular and binocular 3D shape perception. These results are consistent with our computational model of 3D shape recovery.
TWINS IN THE SCHOOL POPULATION
Authors: Sandon F.
Published: August 2011

The following paper is based on a statistical analysis of marks gained by over a thousand twins who have sat for various 11+ examinations for transfer to grammar schools. It is shown that the average ability of twins is well below that of the general population. The correlations between twins of the same sex are much higher than those between twins of opposite sex.
ITEM ANALYSIS BY PROBIT AND FRACTILE GRAPHICAL METHODS
Authors: Das Rhea S.
Published: August 2011

This paper considers five basic questions of item analysis and describes an integrated approach for obtaining the answers which utilizes the methods of probit and fractile graphical analysis. Item difficulty is interpreted as the limen at which 50 per cent of the subjects pass; discriminating power is given by the probit regression coefficient; the item‐ability relation is specified by the probit regression equation; chi square provides an objective test of whether or not the item meets the normal ogive assumption; and plotting items in terms of the limen and regression coefficient permits the selection of items comparable in terms of ability, difficulty, and discrimination. Techniques for the practical application of this approach are also outlined and illustrated.
THE DETECTION OF CHANGE AND THE PERCEPTUAL MOMENT HYPOTHESIS1
Authors: Shallice T.
Published: August 2011

This paper examines Stroud's theory that the perceptual input is quantized in time (the perceptual moment hypothesis). A model of the detection of change based on the theory is compared with other models derived from statistical quality control methods; in particular those using simple and geometric moving averages. They are compared theoretically to see which entails the least computational load for the brain. Empirical comparisons are made with data from loudness thresholds, brightness thresholds, and the perception of causality: all cases in which there is little change in stimulus intensity. The perceptual moment hypothesis is found to be the most satisfactory. Finally, some of the assumptions of the perceptual moment model are examined in more detail and the model is extended to deal with situations in which the intensity of stimulation alters greatly.
Methods for incorporating ordinal information into analysis of variance: Generalizations of one‐tail tests
Authors: Smith Philip T. , Macdonald Ranald R.
Published: August 2011

Methods for incorporating ordinal assumptions into the analysis of the means of k treatments (k > 2) are critically reviewed. These methods are examined under three headings: (1) Global: statistics that give an overall assessment of the presence of a trend in the data (e.g. linear and isotonic regression); (2) Multiple comparisons: statistics based on the repetition (explicit or implicit) of comparisons between pairs of treatments; (3) Joint probability: two statistics are computed, one giving an overall assessment of the differences between the means, the other assessing the specifically ordinal information in the data; the joint significance level of these two statistics is then determined. Numerical examples of all the methods are provided.
Poisson models for assessing rater agreement in discrete response studies
Authors: Feldstein Michael L. , Davis Henry T.
Published: August 2011

In this paper we discuss a method for assessing agreement among raters who are scoring the number of times, a specified event occurs. In such cases, it seems reasonable to define agreement in terms of raters' behaviours in correctly identifying responses which have in fact occurred, and in their falsely counting responses which have not. We exploit the discrete nature of the response variable, and examine a class of models for mean response assuming an underlying Poisson distribution. Test statistics are given for deciding on the applicability of the models, and whether there is agreement with respect to correctly detecting responses, as well as with falsely scoring responses.
Cumulative and local odds‐ratio measures of uniformity of association in two‐way ordered contingency tables
Authors: Ogborn Jon
Published: August 2011

The cumulative odds‐ratio model of uniformity of association in a two‐way ordered contingency table is studied, and compared with Goodman's local odds‐ratio model. It is shown that the cumulative model can be adapted to the deletion of cells, particularly deletion of diagonal cells in square tables, and an example of the improvement of fit obtained is given, and compared with the fit of the local model. The sensitivity of both models to collapse of categories and to changes in marginal totals is discussed, suggesting criteria for choosing between them. The Appendix describes simple computational algorithms for both models, based on minimizing the likelihood ratio over a range of trial parameters.
The analysis of dependencies between time series in psychological experiments
Authors: Brunsdon T. M. , Skinner C. J.
Published: August 2011

The analysis of causal dependence between multiple time series recorded for each of many subjects in a psychological experiment is discussed. The approach of Geweke to the identification and measurement of directional and instantaneous relationships between variables is reviewed. Both unconditional relationships and relationships conditional on values of ‘third variables’ are considered. Methods are applied to time series records of heart rate, body movement, skin conductance and measures of expressed emotion.
A note on the computation of Cohen's kappa
Authors: Dewey Michael E.
Published: August 2011

Observational studies in applied psychology raise particular problems in reliability measurement. Existing techniques for measuring agreement on nominal scales have concentrated on the case where each rater rates all the ratees. The less common case where each ratee has been judged by a different pair of raters has been discussed by Fleiss (1971, 1981) as part of the more general problem where multiple different raters rate each case. This note shows how the formula may be re‐expressed for two different raters per case in a way which leads to the use of existing software for the usual K. This identity may also be useful didactically.
Statistical software for microcomputers: News and reviews
Authors: LOVIE PAT
Published: August 2011

A press release about a new package called SOLO from the BMDP people got me quite excited recently. It promised all manner of statistical goodies and interactive graphics. Actually, SOLO is just a rebadged version of the NCSS package which was reviewed in the November 1988 issue. The sterling equivalent price quoted by Statistical Software Ltd (Cork Technology Park, Model Farm Road, Cork, Ireland) is considerably more than it would cost to import NCSS directly. But I suppose that having support closer to hand than Utah may be worth the extra to some users. By the way, I am expecting, momentarily, an upgrade to NCSS which promises macros and much more. A report should find its way into a later issue.

By the time you read this, the current version of Minitab is almost certain to be Release 7. So, just in case you are wondering why the review which follows is of Release 6, the sorry tale involves a last minute copy of the beta test version of Release 7, scrambled floppy diskettes (they were probably X‐rayed or something similar in Customs) and no time to get replacements. There was nothing for it except to go back to Release 6.

In fact, I doubt very much that Release 7 alters any existing facilities to an extent that would seriously compromise my review. Information gleaned from the documentation suggests that the most important changes are the new features, notably, a data editor, a general linear model command and statistical process control charts. I hope to report on these in the next issue.

For my first review, however, I take a look at Microstat‐II. This is a completely revamped version of the original Microstat package which first saw the light of day over ten years ago.
Standard and bootstrap confidence intervals for the correlation coefficient
Authors: Sievers Walter
Published: August 2011

Several articles in the field of psychology have shown simulation results with the bootstrap‐percentile method and variants for the (Pearson) correlation coefficient. The overall result was that with non‐normal (especially skewed) data, ρ ≠ 0 and small and medium sample sizes, bootstrap methods show poor coverage accuracy. Some of the authors call into question the ability of any bootstrap methods of valid confidence intervals or acceptance regions for testing hypotheses about ρ under these conditions. Simulation results with the iterated bootstrap will be shown, which clearly demonstrate the ability of this bootstrap method to induce valid confidence intervals under all of the above mentioned conditions not only for ρ, but also for the difference of two correlation coefficients and the squared correlation coefficient. Simulations with the point‐biserial correlation coefficient show that for ρph ≠ 0, valid confidence intervals can be achieved with the iterated bootstrap only with medium or large sample sizes, depending on the distribution, while the standard method fails even then.
Estimating and maximizing the utility of sequential selection decisions with a probationary period
Authors: De Corte Wilfried
Published: August 2011

This paper provides a double extension of the two‐stage sequential model developed by Cronbach & Gleser (1965) to estimate the utility of a single‐cohort personnel selection decision. The first extension generalizes the formulation of the two‐stage procedure to that of a general multi‐stage model, whereas the second addresses the situation in which some of the newly hired employees are later judged to perform at an unacceptable level and are therefore dismissed at the end of the training and probationary period. Thus, the new model and the corresponding computational procedure can be used to estimate the utility of selecting sequentially either a fixed quota of selectees (FQS) or a fixed quota of successful selectees (FQSS). In addition, the paper presents an efficient procedure to derive predictor cutoff scores that maximise the utility of the overall selection decision.
Signal Perception in Frogs and Bats and the Evolution of Mating Signals
Authors: Akre Karin L. , Farris Hamilton E. , Lea Amanda M. , Page Rachel A. , Ryan Michael J.
Published: August 2011

Receiver perception limits the evolution of increasingly elaborate calls in túngara frogs.
The "Eyes" Have It
Authors: Shum Anthony K.
Published: August 2011

An autoimmune response to the retina is involved in the pathogenesis of human uveitis.
Imbalance of Th17 Cells and Regulatory T Cells in Tuberculous Pleural Effusion
Authors: Ye Zhi-Jian , Zhou Qiong , Du Rong-Hui , Li Xiao , Huang Bo , Shi Huan-Zhong
Published: August 2011

Both T helper interleukin 17 (IL-17)-producing cells (Th17 cells) and regulatory T cells (Tregs) have been found to be increased in human tuberculous pleural effusion (TPE); however, the possible interaction between Th17 cells and Tregs in TPE remains to be elucidated. The objective of the present study was to investigate the distribution of Th17 cells in relation to Tregs, as well as the mechanism of Tregs in regulating generation and differentiation of Th17 cells in TPE. In the present study, the numbers of Th17 cells and Tregs in TPE and blood were determined by flow cytometry. The regulation and mechanism of CD39+Tregs on generation and differentiation of Th17 cells were explored. Our data demonstrated that the numbers of Th17 cells and CD39+Tregs were both increased in TPE compared with blood. Th17 cell numbers were correlated negatively with Tregs in TPE but not in blood. When naïve CD4+T cells were cultured with CD39+Tregs, Th17 cell numbers decreased as CD39+Treg numbers increased, and the addition of the anti-latency-associated peptide monoclonal antibody to the coculture reversed the inhibitory effect exerted by CD39+Tregs. This study shows that Th17/Treg imbalance exists in TPE and that pleural CD39+Tregs inhibit generation and differentiation of Th17 cells via a latency-associated peptide-dependent mechanism.
Rous Sarcoma Virus Gag Has No Specific Requirement for Phosphatidylinositol-(4,5)-Bisphosphate for Plasma Membrane Association
In Vivo
or for Liposome Interaction
In Vitro
Authors: Chan Jany , Dick Robert A. , Vogt Volker M.
Published: August 2011

The MA domain of the retroviral Gag protein mediates interactions with the plasma membrane, which is the site of productive virus release. HIV-1 MA has a phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P
2
] binding pocket; depletion of this phospholipid from the plasma membrane compromises Gag membrane association and virus budding. We used multiple methods to examine the possible role of PI(4,5)P
2
in Gag-membrane interaction of the alpharetrovirus Rous sarcoma virus (RSV). In contrast to HIV-1, which was tested in parallel, neither membrane localization of RSV Gag-GFP nor release of virus-like particles was affected by phosphatase-mediated depletion of PI(4,5)P
2
in transfected avian cells. In liposome flotation experiments, RSV Gag required acidic lipids for binding but showed no specificity for PI(4,5)P
2
. Mono-, di-, and triphosphorylated phosphatidylinositol phosphate (PIP) species as well as high concentrations of phosphatidylserine (PS) supported similar levels of flotation. A mutation that increases the overall charge of RSV MA also enhanced Gag membrane binding. Contrary to previous reports, we found that high concentrations of PS, in the absence of PIPs, also strongly promoted HIV-1 Gag flotation. Taken together, we interpret these results to mean that RSV Gag membrane association is driven by electrostatic interactions and not by any specific association with PI(4,5)P
2
.
Major Histocompatibility Complex Class II Transactivator CIITA Is a Viral Restriction Factor That Targets Human T-Cell Lymphotropic Virus Type 1 Tax-1 Function and Inhibits Viral Replication
Authors: Tosi Giovanna , Forlani Greta , Andresen Vibeke , Turci Marco , Bertazzoni Umberto , Franchini Genoveffa , Poli Guido , Accolla Roberto S.
Published: August 2011

Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of an aggressive malignancy of CD4
+
T lymphocytes. Since the viral transactivator Tax-1 is a major player in T-cell transformation, targeting Tax-1 protein is regarded as a possible strategy to arrest viral replication and to counteract neoplastic transformation. We demonstrate that CIITA, the master regulator of major histocompatibility complex class II gene transcription, inhibits HTLV-1 replication by blocking the transactivating function of Tax-1 both when exogenously transfected in 293T cells and when endogenously expressed by a subset of U937 promonocytic cells. Tax-1 and CIITA physically interact
in vivo
via the first 108 amino acids of Tax-1 and two CIITA adjacent regions (amino acids 1 to 252 and 253 to 410). Interestingly, only CIITA 1-252 mediated Tax-1 inhibition, in agreement with the fact that CIITA residues from positions 64 to 124 were required to block Tax-1 transactivation. CIITA inhibitory action on Tax-1 correlated with the nuclear localization of CIITA and was independent of the transcription factor NF-YB, previously involved in CIITA-mediated inhibition of Tax-2 of HTLV-2. Instead, CIITA severely impaired the physical and functional interaction of Tax-1 with the cellular coactivators p300/CBP-associated factor (PCAF), cyclic AMP-responsive element binding protein (CREB), and activating transcription factor 1 (ATF1), which are required for the optimal activation of HTLV-1 promoter. Accordingly, the overexpression of PCAF, CREB, and ATF1 restored Tax-1-dependent transactivation of the viral long-terminal-repeat promoter inhibited by CIITA. These findings strongly support our original observation that CIITA, beside increasing the antigen-presenting function for pathogen antigens, acts as an endogenous restriction factor against human retroviruses by blocking virus replication and spreading.
Targeted Bacterial Immunity Buffers Phage Diversity
Authors: Haerter Jan O. , Trusina Ala , Sneppen Kim
Published: August 2011

Bacteria have evolved diverse defense mechanisms that allow them to fight viral attacks. One such mechanism, the clustered, regularly interspaced, short palindromic repeat (CRISPR) system, is an adaptive immune system consisting of genetic loci that can take up genetic material from invasive elements (viruses and plasmids) and later use them to reject the returning invaders. It remains an open question how, despite the ongoing evolution of attack and defense mechanisms, bacteria and viral phages manage to coexist. Using a simple mathematical model and a two-dimensional numerical simulation, we found that CRISPR adaptive immunity allows for robust phage-bacterium coexistence even when the number of virus species far exceeds the capacity of CRISPR-encoded genetic memory. Coexistence is predicted to be a consequence of the presence of many interdependent species that stress but do not overrun the bacterial defense system.
Chlamydia trachomatisserovars in community-based HIV-positive and HIV-negative men who have sex with men in Sydney, Australia
Authors: Templeton D J , Twin J , Jin F , Grulich A E , Garland S M , Tabrizi S N
Published: August 2011

Objectives

There are few data on the distribution of specificChlamydia trachomatisserovars among men who have sex with men (MSM) outside clinical settings. To investigate these patterns, serovar determination was performed on chlamydia-positive samples from two community-based cohort studies of HIV-positive and HIV-negative MSM in Sydney, Australia.

Methods

From January 2005 to June 2007 all positiveC trachomatispharyngeal, urine and anal samples were evaluated. The serovar of eachC trachomatisinfection was determined byomp1gene sequencing with confirmatory quantitative PCR screening. Symptom data were routinely reported by study participants at the time of testing.

Results

Serovar determination was possible for 54 samples among 52 participants. Seven samples were not able to be typed. Site-specific symptoms were reported by fewer than 10% of participants diagnosed with pharyngeal and anogenital chlamydia. The most commonly identified serovars were serovar D (n=32, 59.3%, 95% CI 45.0 to 72.4), followed by serovar G (n=11, 20.4%, 95% CI 10.6 to 33.5) and serovar J (n=5, 9.3%, 95% CI 3.1 to 20.3). Only one lymphogranuloma venereum serovar was identified (L2b).

Conclusions

This community-based study found a similar distribution of chlamydia serovars to that observed among Australian community-based MSM several years ago, and serovar distribution recently observed among predominantly symptomatic MSM at a Sydney clinic. These findings suggest little change inC trachomatisserovar distribution in Australian MSM over the past decade and a lack of correlation of specific chlamydia serovars with anogenital symptoms among MSM.
Measurement and calculation of 13C chemical shift tensors in α-glucose and α-glucose monohydrate
Authors: Brouwer Darren H. , Langendoen Kevin P. , Ferrant Quentin
Published: August 2011

The 13C chemical shift tensors of two crystalline forms of glucose (α-glucose and α-glucose·H2O) were determined from one-dimensional (1D) and two-dimensional (2D) solid-state nuclear magnetic resonance (NMR) spectroscopy experiments. The experimental values determined from 1D and 2D methods are in very good agreement. Quantum chemical calculations were also carried out using the gauge-including projector augmented wave (GIPAW) method for plane-wave density functional theory (DFT) as implemented in the CAmbridge Serial Total Energy Package (CASTEP). The calculated 13C chemical shifts were found to be in excellent agreement with experimental values for crystal structures that had their hydrogen atoms optimized and after an appropriate calibration was applied to convert calculated chemical shieldings into chemical shifts. The work presented here lays an important foundation for future solid-state NMR and quantum chemical calculation investigations of the various crystalline forms of cellulose.
Resonance assignments and secondary structure analysis of dynein light chain 8 by magic-angle spinning NMR spectroscopy
Authors: Sun Shangjin , Butterworth Andrew H. , Paramasivam Sivakumar , Yan Si , Lightcap Christine M. , Williams John C. , Polenova Tatyana
Published: August 2011

Dynein light chain LC8 is the smallest subunit of the dynein motor complex and has been shown to play important roles in both dynein-dependent and dynein-independent physiological functions via its interaction with a number of its binding partners. It has also been linked to pathogenesis including roles in viral infections and tumorigenesis. Structural information for LC8-target proteins is critical to understanding the underlying function of LC8 in these complexes. However, some LC8-target interactions are not amenable to structural characterization by conventional structural biology techniques owing to their large size, low solubility, and crystallization difficulties. Here, we report magic-angle spinning (MAS) NMR studies of the homodimeric apo-LC8 protein as a first effort in addressing more complex, multi-partner, LC8-based protein assemblies. We have established site-specific backbone and side-chain resonance assignments for the majority of the residues of LC8, and show TALOS+-predicted torsion angles ϕ and ψ in close agreement with most residues in the published LC8 crystal structure. Data obtained through these studies will provide the first step toward using MAS NMR to examine the LC8 structure, which will eventually be used to investigate protein–protein interactions in larger systems that cannot be determined by conventional structural studies.
A Quasi-Three-Dimensional Variably Saturated Groundwater Flow Model for Climate Modeling
Authors: Xie Zhenghui , Di Zhenhua , Luo Zhendong , Ma Qian
Published: August 2011

In this study, a quasi-three-dimensional, variably saturated groundwater flow model was developed by approximately dividing the three-dimensional soil water and groundwater flow into an unsaturated vertical soil water flow and a horizontal groundwater flow to simulate the interactions among soil water, groundwater, and vegetation. The developed model consists of a one-dimensional unsaturated soil water flow model with the water table as the moving boundary using an adaptive grid structure for a vertical soil column formed based on discrete grid cells in a horizontal domain, a two-dimensional groundwater flow model for the horizontal domain, and an interface model connecting the two components for the horizontal grid cells in the domain. Synthetic experiments by the model were conducted to test the sensitivities of the model parameters of river elevation, ground surface hydraulic conductivity, and surface flux, and the results from the experiments showed the robustness of the proposed model under different conditions. Comparison of the simulation by the model and that by a full three-dimensional scheme showed its feasibility and efficiency. A case of stream water conveyance in the lower reaches of the Tarim River was then applied to validate the developed model for simulation of the water table elevations at the Yingsu section. Finally, a numerical experiment by the model for the Tarim River basin was conducted to discuss the groundwater latent flow for large-scale high-relief topography with stream water conveyance. The results show that the model can simulate the water table reasonably well.
Observations of Tidally Induced Currents over the Continental Slope of the Laptev Sea, Arctic Ocean
Authors: Pnyushkov A. V. , Polyakov I. V.
Published: August 2011

Two year-long (2004–05 and 2005–06) records of currents from two moorings deployed at the continental slope of the Laptev Sea (78°26′N, 125°40′E) are used in order to define the properties of tidal currents in the upper ~200-m ocean layer. Harmonic and spectral analyses of currents showed that the semidiurnal tidal constituent S2 dominates over the semidiurnal M2 and diurnal constituents. This dominance of the S2 constituent in the tidal currents is due to resonant interaction of the superinertial wave with sloping bottom topography. In contrast to the tidal currents, sea level changes are dominated by the M2 constituent, as seen from a tidal model by L. Padman and S. Erofeeva, using assimilation of observational data. Strong anticorrelation (−0.73 ± 0.05) was found between the upper 50-m S2 current amplitudes and local sea ice concentration, with fourfold (from ~2.0 to 8.5 cm s−1) amplification of tidal currents under ice-free conditions. This is probably due to a change of local resonance conditions for the S2 tidal current. These findings may be important for understanding the increasing role of tides in a seasonally ice-free Arctic Ocean.
Synthesis and antimicrobial evaluation of new 1,4-dihydro-4-pyrazolylpyridines and 4-pyrazolylpyridines
Authors: Prakash Om , Hussain Khalid , Kumar Ravi , Wadhwa Deepak , Sharma Chetan , Aneja Kamal R
Published: August 2011

Background

Dialkyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylates (1,4-DHP) have now been recognized as vital drugs. Some of these derivatives such as amlodipine, felodipine, isradipine, etc. have been commercialized. In view of wide range of biological properties associated with 1,4-DHP and owing to the biological importance of the oxidation step of 1,4-DHP, we carried out the synthesis and antimicrobial evaluation of new diethyl 1,4-dihydro-2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (2a-g) and diethyl 2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (3a-g).

Results

Synthesis of a series of new diethyl 1,4-dihydro-2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (2a-g) has been accomplished by multicomponent cyclocondensation reaction of ethyl acetoacetate, 3-aryl-1-phenyl pyrazole-4-carboxaldehyde (1a-g) and ammonium acetate. The dihydropyridines 2a-g were smoothly converted to new diethyl 2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (3a-g) using HTIB ([Hydroxy (tosyloxy)iodo]benzene, Koser's reagent) as the oxidizing agent. The antimicrobial studies of the title compounds, 2a-g & 3a-g, are also described.