bluuebunny/crossref_metadata_2025 huggingface dataset:
Phospholipase C γ1 regulates early secretory trafficking and cell migration via interaction with p115
Authors: Millarte Valentina , Boncompain Gaelle , Tillmann Kerstin , Perez Franck , Sztul Elizabeth , Farhan Hesso
Published: April 2015

The role of early secretory trafficking in the regulation of cell motility remains incompletely understood. Here we used a small interfering RNA screen to monitor the effects on structure of the Golgi apparatus and cell migration. Two major Golgi phenotypes were observed—fragmented and small Golgi. The latter exhibited a stronger correlation with a defect in cell migration. Among the small Golgi hits, we focused on phospholipase C γ1 (PLCγ1). We show that PLCγ1 regulates Golgi structure and cell migration independently of its catalytic activity but in a manner that depends on interaction with the tethering protein p115. PLCγ1 regulates the dynamics of p115 in the early secretory pathway, thereby controlling trafficking from the endoplasmic reticulum to the Golgi. Our results uncover a new function of PLCγ1 that is independent of its catalytic function and link early secretory trafficking to the regulation of cell migration.
Part 1 Constitutionalism and Islam: Conceptual Issues, 1.2 The Centrality of Sharī‘ah to Government and Constitutionalism in Islam
Authors: Khaled Abou El Fadl
Published: April 2015

This chapter examines potentialities, i.e. the doctrinal aspects in Islamic political thought that could legitimate, promote, or subvert the emergence of a constitutional practice in Muslim cultures. These doctrinal potentialities exist in a dormant state until they are co-opted and directed by systematic thought supported by cumulative social practices. The discussions focus on doctrinal potentialities or concepts constructed by the interpretive activity of Muslim scholars (primarily jurists). It covers the notion of constitutionalism and majoritarian democracy; the main concepts of Islamic political thought; justice as a core constitutional value; the instrumentalities of government in Islamic thought; the possibility of individual rights; and constitutionalism and Sharīʻah.
Part 2 Interrelations between Constitutionalism and Sharī’ah: Antagonism or Complementarity?, 2.4 The Relationship between the Constitution and the Sharī‘ah in Egypt
Authors: Adel Omar Sherif
Published: April 2015

Recent political developments in Egypt have triggered debates over the role of Islam in the country's future constitution. This chapter looks back into the legal history of Egypt in order to provide an informative basis. It discusses constitutional developments in Egypt and how references to Islamic Sharīʻah became incorporated into state constitutional documents. It considers the rulings of the Supreme Constitutional Court on Art. 2 of the 1971 Constitution, which provides for Islamic Sharīʻah to be the principal source of legislation.
Part 4 Constitutionalism and Separation of Powers, 4.8 Indonesia: A Presidential System with Checks and Balances
Authors: Nadirsyah Hosen
Published: April 2015

This chapter focuses on the presidential system of Indonesia. The amendments to the 1945 Constitution have transformed the constitution from a vague and incomplete document rooted in the antidemocratic political philosophy of organic statism into a more coherent, complete, democratic framework for a presidential system with significant separation of powers and checks and balances. The very fact that Indonesia is the largest Muslim country in the world did not lead Islamic political parties to propose that Indonesia should become an Islamic state. According to the amendments, Indonesia remains a republic, with a presidential system and three branches of government. The chapter discusses the form of the Indonesian state, method of election, requirements, accountability, and relationship among the executive, the parliament, and the judiciary.
Part 5 Emerging Constitutions in Islamic Countries, 5.2 Constitutionalism and Islam in Libya
Authors: Karim Mezran
Published: April 2015

This chapter explores the deep and slow currents that have permeated Libyan society as it has evolved in the last century. It starts with a brief discussion of the debate surrounding the constitution of the short-lived Tripoli Republic around 1918, and continues with an analysis of the eventful period that preceded independence from which emerged the constitutional monarchy that ruled Libya for the following eighteen years. It looks at the various currents that emerged in that period because it is the unresolved disputes, the bad compromises, and the frustrations of the nationalist movement that led to the enactment of a constitution that was too complex and muddled to begin with, and inadequate in reaching the main purpose of a constitution: limitation of power.
Part 5 Emerging Constitutions in Islamic Countries, 5.10 Constitutionalism in an Islamic Republic: The Principles of the Afghan Constitution and the Conflicts between Them
Authors: Ramin S Moschtaghi
Published: April 2015

This chapter analyzes the tensions between Islam and the principles of the Afghan Constitution. It first identifies the different principles of the Afghan Constitution and then examines points of conflict between them. Based on an assessment of a specific conflict between Islamic law and human rights concerning the treatment of apostates in Islam and the freedom of religion, it proposes a practical approach how to solve conflicts between different Afghan constitutional principles and values.
edgeRun: an R package for sensitive, functionally relevant differential expression discovery using an unconditional exact test
Authors: Dimont Emmanuel , Shi Jiantao , Kirchner Rory , Hide Winston
Published: April 2015

Summary: Next-generation sequencing platforms for measuring digital expression such as RNA-Seq are displacing traditional microarray-based methods in biological experiments. The detection of differentially expressed genes between groups of biological conditions has led to the development of numerous bioinformatics tools, but so far, few exploit the expanded dynamic range afforded by the new technologies. We present edgeRun, an R package that implements an unconditional exact test that is a more powerful version of the exact test in edgeR. This increase in power is especially pronounced for experiments with as few as two replicates per condition, for genes with low total expression and with large biological coefficient of variation. In comparison with a panel of other tools, edgeRun consistently captures functionally similar differentially expressed genes.

Availability and implementation: The package is freely available under the MIT license from CRAN (http://cran.r-project.org/web/packages/edgeRun).

Contact:  edimont@mail.harvard.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Protein homology reveals new targets for bioactive small molecules
Authors: Gfeller David , Zoete Vincent
Published: April 2015

Motivation: The functional impact of small molecules is increasingly being assessed in different eukaryotic species through large-scale phenotypic screening initiatives. Identifying the targets of these molecules is crucial to mechanistically understand their function and uncover new therapeutically relevant modes of action. However, despite extensive work carried out in model organisms and human, it is still unclear to what extent one can use information obtained in one species to make predictions in other species.

Results: Here, for the first time, we explore and validate at a large scale the use of protein homology relationships to predict the targets of small molecules across different species. Our results show that exploiting target homology can significantly improve the predictions, especially for molecules experimentally tested in other species. Interestingly, when considering separately orthology and paralogy relationships, we observe that mapping small molecule interactions among orthologs improves prediction accuracy, while including paralogs does not improve and even sometimes worsens the prediction accuracy. Overall, our results provide a novel approach to integrate chemical screening results across multiple species and highlight the promises and remaining challenges of using protein homology for small molecule target identification.

Availability and implementation: Homology-based predictions can be tested on our website http://www.swisstargetprediction.ch.

Contact:  david.gfeller@unil.ch or vincent.zoete@isb-sib.ch.

Supplementary information:  Supplementary data are available at Bioinformatics online.
Analysis of impedance-based cellular growth assays
Authors: Witzel Franziska , Fritsche-Guenther Raphaela , Lehmann Nadine , Sieber Anja , Blüthgen Nils
Published: April 2015

Motivation: Impedance-based technologies are advancing methods for measuring proliferation of adherent cell cultures non-invasively and in real time. The analysis of the resulting data has so far been hampered by inappropriate computational methods and the lack of systematic data to evaluate the characteristics of the assay.

Results: We used a commercially available system for impedance-based growth measurement (xCELLigence) and compared the reported cell index with data from microscopy. We found that the measured signal correlates linearly with the cell number throughout the time of an experiment with sufficient accuracy in subconfluent cell cultures. The resulting growth curves for various colon cancer cells could be well described with the empirical Richards growth model, which allows for extracting quantitative parameters (such as characteristic cycle times). We found that frequently used readouts like the cell index at a specific time or the area under the growth curve cannot be used to faithfully characterize growth inhibition. We propose to calculate the average growth rate of selected time intervals to accurately estimate time-dependent IC50 values of drugs from growth curves.

Contact:  nils.bluethgen@charite.de

Supplementary information:  Supplementary data are available at Bioinformatics online.
A Recent Expansion of the RXLR Effector Gene Avrblb2 Is Maintained in Global Populations of Phytophthora infestans Indicating Different Contributions to Virulence
Authors: Oliva Ricardo F. , Cano Liliana M. , Raffaele Sylvain , Win Joe , Bozkurt Tolga O. , Belhaj Khaoula , Oh Sang-Keun , Thines Marco , Kamoun Sophien
Published: April 2015

The introgression of disease resistance (R) genes encoding immunoreceptors with broad-spectrum recognition into cultivated potato appears to be the most promising approach to achieve sustainable management of late blight caused by the oomycete pathogen Phytophthora infestans. Rpi-blb2 from Solanum bulbocastanum shows great potential for use in agriculture based on preliminary potato disease trials. Rpi-blb2 confers immunity by recognizing the P. infestans avirulence effector protein AVRblb2 after it is translocated inside the plant cell. This effector belongs to the RXLR class of effectors and is under strong positive selection. Structure-function analyses revealed a key polymorphic amino acid (position 69) in AVRblb2 effector that is critical for activation of Rpi-blb2. In this study, we reconstructed the evolutionary history of the Avrblb2 gene family and further characterized its genetic structure in worldwide populations. Our data indicate that Avrblb2 evolved as a single-copy gene in a putative ancestral species of P. infestans and has recently expanded in the Phytophthora spp. that infect solanaceous hosts. As a consequence, at least four variants of AVRblb2 arose in P. infestans. One of these variants, with a Phe residue at position 69, evades recognition by the cognate resistance gene. Surprisingly, all Avrblb2 variants are maintained in pathogen populations. This suggests a potential benefit for the pathogen in preserving duplicated versions of AVRblb2, possibly because the variants may have different contributions to pathogen fitness in a diversified solanaceous host environment.
Leaf Doctor: A New Portable Application for Quantifying Plant Disease Severity
Authors: Pethybridge Sarah J. , Nelson Scot C.
Published: April 2015

An interactive, iterative smartphone application was used on color images to distinguish diseased from healthy plant tissues and calculate percentage of disease severity. The user touches the application’s display screen to select up to eight different colors that represent healthy tissues. The user then moves a threshold slider until only the symptomatic tissues have been transformed into a blue hue. The pixelated image is then analyzed to calculate the disease percentage. This study reports the accuracy, precision, and robustness of Leaf Doctor using six different diseases with typical lesions of varying severity. Estimates of disease severity from Leaf Doctor were highly accurate (R2 ≥ 0.79; Cb ≥ 0.959) compared with estimates obtained from the discipline-standard, Assess. Precision was operationally defined as the ability of a rater to use Leaf Doctor and repeatedly obtain similar percentages of disease severity for the same image. Coefficients of variation were low (0.51 to 14.1%) across all disease datasets but a significant negative relationship was found between the coefficient of variation of estimates and mean disease severity. Other advantages of Leaf Doctor included comparatively less time for image processing, low cost, ease of use, ability to send results by e-mail, and the ability to create realistic standard area diagrams. Leaf Doctor is compatible with iPhone, iPad, and iPod touch and is optimized for iPhone 5. It is available as a free download at the iTunes Store.
Virulence and Molecular Diversity of the Puccinia striiformis f. sp. tritici Population in Xinjiang in Relation to Other Regions of Western China
Authors: Zhan Gangming , Wang Fuping , Wan Cuiping , Han Qingmei , Huang Lili , Kang Zhensheng , Chen Xianming
Published: April 2015

In recent years, wheat stripe rust caused severe yield losses in western China, especially the Xinjiang Autonomous Region. The population of the stripe rust fungus Puccinia striiformis f. sp. tritici in the vast region had not been well studied. To determine the population structure and compare it with the populations in the neighboring provinces or autonomous regions, P. striiformis f. sp. tritici isolates from Xinjiang, Qinghai, Gansu, Ningxia, and Tibet in western China were characterized by virulence tests with 19 wheat genotypes that are used to differentiate races of P. striiformis f. sp. tritici in China and by genotyping tests with 15 simple-sequence repeat (SSR) markers. In total, 56 races, including 39 previously known and 17 new races, were identified from 308 isolates obtained from the three epidemiological regions covering five provinces, of which 27 previously known and 8 unknown races were detected in Xinjiang, higher than the numbers in either of the other two regions. The races in Xinjiang consisted of those historically and recently predominant races in other regions of China. The P. striiformis f. sp. tritici population in Xinjiang had a higher genetic diversity than populations in other epidemiological regions. Molecular variation among subpopulations within Xinjiang was higher than in other regions. Both virulence and molecular data indicate that the P. striiformis f. sp. tritici population in Xinjiang is related to but more diverse than those in other epidemiological regions. The results show that Xinjiang is an important stripe rust epidemiological region in China, and the information should be useful for control of the disease in the region as well as in other regions.
Combining Models is More Likely to Give Better Predictions than Single Models
Authors: Hu Xiaoping , Madden Laurence V. , Edwards Simon , Xu Xiangming
Published: April 2015

In agricultural research, it is often difficult to construct a single “best” predictive model based on data collected under field conditions. We studied the relative prediction performance of combining empirical linear models over the single best model in relation to number of models to be combined, number of variates in the models, magnitude of residual errors, and weighting schemes. Two scenarios were simulated: the modeler did or did not know the relative of performance of the models to be combined. For the former case, model averaging is achieved either through weights based on the Akaike Information Criterion (AIC) statistic or with arithmetic averaging; for the latter case, only the arithmetic averaging is possible (because the relative model predictive performance is not known for a common dataset). In addition to two experimental datasets on oat mycotoxins in relation to environmental variables, two datasets were generated assuming a consistent correlation structure among explanatory variates with two magnitudes of residual errors. For the majority of cases, model averaging resulted in improved prediction performance over the single-model predictions, especially when a modeler does not have the information of relative model performance. The fewer variates in the models to be combined, the greater is improvement of model averaging over the single-model predictions. Combining models led to very little improvement over individual models when there were many variates in individual models. Overall, simple arithmetic averaging resulted in slightly better performance than the AIC-based weighted averaging. The advantage in model averaging is also noticeable for larger residual errors. This study suggests that model averaging generally performs better than single-model predictions, especially when a modeler does not have information on the relative performance of the candidate models.
Turbulence triggers vigorous swimming but hinders motion strategy in planktonic copepods
Authors: Michalec François-Gaël , Souissi Sami , Holzner Markus
Published: April 2015

Calanoid copepods represent a major component of the plankton community. These small animals reside in constantly flowing environments. Given the fundamental role of behaviour in their ecology, it is especially relevant to know how copepods perform in turbulent flows. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of hundreds of adult
Eurytemora affinis
swimming freely under realistic intensities of homogeneous turbulence. We demonstrate that swimming contributes substantially to the dynamics of copepods even when turbulence is significant. We show that the contribution of behaviour to the overall dynamics gradually reduces with turbulence intensity but regains significance at moderate intensity, allowing copepods to maintain a certain velocity relative to the flow. These results suggest that
E. affinis
has evolved an adaptive behavioural mechanism to retain swimming efficiency in turbulent flows. They suggest the ability of some copepods to respond to the hydrodynamic features of the surrounding flow. Such ability may improve survival and mating performance in complex and dynamic environments. However, moderate levels of turbulence cancelled gender-specific differences in the degree of space occupation and innate movement strategies. Our results suggest that the broadly accepted mate-searching strategies based on trajectory complexity and movement patterns are inefficient in energetic environments.
Evidence of rapid change in genetic structure and diversity during range expansion in a recovering large terrestrial carnivore
Authors: Hagen Snorre B. , Kopatz Alexander , Aspi Jouni , Kojola Ilpo , Eiken Hans Geir
Published: April 2015

Recovery of natural populations occurs often with simultaneous or subsequent range expansions. According to population genetic theory, genetic structuring emerges at the expansion front together with decreasing genetic diversity, owing to multiple founder events. Thereupon, as the expansion proceeds and connectivity among populations is established, homogenization and a resurgence of genetic diversity are to be expected. Few studies have used a fine temporal scale combined with genetic sampling to track range expansions as they proceed in wild animal populations. As a natural experiment, the historical eradication of large terrestrial carnivores followed by their recovery and recolonization may facilitate empirical tests of these ideas. Here, using brown bear (Ursus arctos) as model species, we tested predictions from genetic theory of range expansion. Individuals from all over Finland were genotyped for every year between 1996 and 2010 using 12 validated autosomal microsatellite markers. A latitudinal shift of about 110 km was observed in the distribution and delineation of genetic clusters during this period. As the range expansion proceeded, we found, as theory predicts, that the degree of genetic structure decreased, and that both genetic variation and admixture increased. The genetic consequences of range expansions may first be detected after multiple generations, but we found major changes in genetic composition after just 1.5 generations, accompanied by population growth and increased migration. These rapid genetic changes suggest an ongoing concerted action of geographical and demographic expansion combined with substantial immigration of bears from Russia during the recovery of brown bears within the large ecosystem of northern Europe.
Female major histocompatibility complex type affects male testosterone levels and sperm number in the horse (Equus caballus)
Authors: Burger D. , Dolivo G. , Marti E. , Sieme H. , Wedekind C.
Published: April 2015

Odours of vertebrates often contain information about the major histocompatibility complex (MHC), and are used in kin recognition, mate choice or female investment in pregnancy. It is, however, still unclear whether MHC-linked signals can also affect male reproductive strategies. We used horses (Equus caballus) to study this question under experimental conditions. Twelve stallions were individually exposed either to an unfamiliar MHC-similar mare and then to an unfamiliar MHC-dissimilar mare, or vice versa. Each exposure lasted over a period of four weeks. Peripheral blood testosterone levels were determined weekly. Three ejaculates each were collected in the week after exposure to both mares (i.e. in the ninth week) to determine mean sperm number and sperm velocity. We found high testosterone levels when stallions were kept close to MHC-dissimilar mares and significantly lower ones when kept close to MHC-similar mares. Mean sperm number per ejaculate (but not sperm velocity) was positively correlated to mean testosterone levels and also affected by the order of presentation of mares: sperm numbers were higher if MHC-dissimilar mares were presented last than if MHC-similar mares were presented last. We conclude that MHC-linked signals influence testosterone secretion and semen characteristics, two indicators of male reproductive strategies.
Genetic Basis of Transcriptome Diversity inDrosophila melanogaster
Authors: Huang Wen , Carbone Mary Anna , Magwire Michael M. , Peiffer Jason A. , Lyman Richard F. , Stone Eric A. , Anholt Robert R. H. , Mackay Trudy F. C.
Published: April 2015

Understanding how DNA sequence variation is translated into variation for complex phenotypes has remained elusive, but is essential for predicting adaptive evolution, selecting agriculturally important animals and crops, and personalized medicine. Here, we quantified genome-wide variation in gene expression in the sequenced inbred lines of theDrosophila melanogasterGenetic Reference Panel (DGRP). We found that a substantial fraction of theDrosophilatranscriptome is genetically variable and organized into modules of genetically correlated transcripts, which provide functional context for newly identified transcribed regions. We identified regulatory variants for the mean and variance of gene expression, the latter of which could often be explained by an epistatic model. Expression quantitative trait loci for the mean, but not the variance, of gene expression were concentrated near genes. This comprehensive characterization of population scale diversity of transcriptomes and its genetic basis in the DGRP is critically important for a systems understanding of quantitative trait variation.
Bandage: interactive visualisation ofde novogenome assemblies
Authors: Wick Ryan R. , Schultz Mark B. , Zobel Justin , Holt Kathryn E.
Published: April 2015

Whilede novoassembly graphs contain assembled contigs (nodes), the connections between those contigs (edges) are difficult for users to access. Bandage (aBioinformaticsApplication forNavigatingDe novoAssemblyGraphsEasily) is a tool for visualising assembly graphs with connections. Users can zoom in to specific areas of the graph and interact with it by moving nodes, adding labels, changing colours and extracting sequences. BLAST searches can be performed within the Bandage GUI and the hits are displayed as highlights in the graph. By displaying connections between contigs, Bandage presents new possibilities for analysingde novoassemblies that are not possible through investigation of contigs alone.

Availability and implementation

Source code and binaries are freely available athttps://github.com/rrwick/Bandage. Bandage is implemented in C++ and supported on Linux, OS X and Windows.

Contact

rrwick@gmail.com

Supplementary information

A full feature list and screenshots are available atBioinformaticsonline andhttp://rrwick.github.io/Bandage.
Generating effective models and parameters for RNA genetic circuits
Authors: Hu Chelsea Y , Varner Jeffrey D , Lucks Julius B
Published: April 2015

RNA genetic circuitry is emerging as a powerful tool to control gene expression. However, little work has been done to create a theoretical foundation for RNA circuit design. A prerequisite to this is a quantitative modeling framework that accurately describes the dynamics of RNA circuits. In this work, we develop an ordinary differential equation model of transcriptional RNA genetic circuitry, using an RNA cascade as a test case. We show that parameter sensitivity analysis can be used to design a set of four simple experiments that can be performed in parallel using rapid cell-free transcription-translation (TX-TL) reactions to determine the thirteen parameters of the model. The resulting model accurately recapitulates the dynamic behavior of the cascade, and can be easily extended to predict the function of new cascade variants that utilize new elements with limited additional characterization experiments. Interestingly, we show that inconsistencies between model predictions and experiments led to the model-guided discovery of a previously unknown maturation step required for RNA regulator function. We also determine circuit parameters in two different batches of TX-TL, and show that batch-to-batch variation can be attributed to differences in parameters that are directly related to the concentrations of core gene expression machinery. We anticipate the RNA circuit models developed here will inform the creation of computer aided genetic circuit design tools that can incorporate the growing number of RNA regulators, and that the parameterization method will find use in determining functional parameters of a broad array of natural and synthetic regulatory systems.
The X-ray Pump–Probe instrument at the Linac Coherent Light Source
Authors: Chollet Matthieu , Alonso-Mori Roberto , Cammarata Marco , Damiani Daniel , Defever Jim , Delor James T. , Feng Yiping , Glownia James M. , Langton J. Brian , Nelson Silke , Ramsey Kelley , Robert Aymeric , Sikorski Marcin , Song Sanghoon , Stefanescu Daniel , Srinivasan Venkat , Zhu Diling , Lemke Henrik T. , Fritz David M.
Published: April 2015

The X-ray Pump–Probe instrument achieves femtosecond time-resolution with hard X-ray methods using a free-electron laser source. It covers a photon energy range of 4–24 keV. A femtosecond optical laser system is available across a broad spectrum of wavelengths for generating transient states of matter. The instrument is designed to emphasize versatility and the scientific goals encompass ultrafast physical, chemical and biological processes involved in the transformation of matter and transfer of energy at the atomic scale.
The FERMI free-electron lasers
Authors: Allaria E. , Badano L. , Bassanese S. , Capotondi F. , Castronovo D. , Cinquegrana P. , Danailov M. B. , D'Auria G. , Demidovich A. , De Monte R. , De Ninno G. , Di Mitri S. , Diviacco B. , Fawley W. M. , Ferianis M. , Ferrari E. , Gaio G. , Gauthier D. , Giannessi L. , Iazzourene F. , Kurdi G. , Mahne N. , Nikolov I. , Parmigiani F. , Penco G. , Raimondi L. , Rebernik P. , Rossi F. , Roussel E. , Scafuri C. , Serpico C. , Sigalotti P. , Spezzani C. , Svandrlik M. , Svetina C. , Trovó M. , Veronese M. , Zangrando D. , Zangrando M.
Published: April 2015

FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and is now in user operation with its first FEL line, FEL-1, covering the wavelength range between 100 and 20 nm. The second FEL line, FEL-2, a high-gain harmonic generation double-stage cascade covering the wavelength range 20–4 nm, has also completed commissioning and the first user call has been recently opened. An overview of the typical operating modes of the facility is presented.
Structure ofCryptosporidiumIMP dehydrogenase bound to an inhibitor within vivoantiparasitic activity
Authors: Kim Youngchang , Makowska-Grzyska Magdalena , Gorla Suresh Kumar , Gollapalli Deviprasad R. , Cuny Gregory D. , Joachimiak Andrzej , Hedstrom Lizbeth
Published: April 2015

Inosine 5′-monophosphate dehydrogenase (IMPDH) is a promising target for the treatment ofCryptosporidiuminfections. Here, the structure ofC. parvumIMPDH (CpIMPDH) in complex with inosine 5′-monophosphate (IMP) and P131, an inhibitor within vivoanticryptosporidial activity, is reported. P131 contains two aromatic groups, one of which interacts with the hypoxanthine ring of IMP, while the second interacts with the aromatic ring of a tyrosine in the adjacent subunit. In addition, the amine and NO2moieties bind in hydrated cavities, forming water-mediated hydrogen bonds to the protein. The design of compounds to replace these water molecules is a new strategy for the further optimization ofC. parvuminhibitors for both antiparasitic and antibacterial applications.
The structure of tubulin-binding cofactor A fromLeishmania majorinfers a mode of association during the early stages of microtubule assembly
Authors: Barrack Keri L. , Fyfe Paul K. , Hunter William N.
Published: April 2015

Tubulin-binding cofactor A (TBCA) participates in microtubule formation, a key process in eukaryotic biology to create the cytoskeleton. There is little information on how TBCA might interact with β-tubulin en route to microtubule biogenesis. To address this, the protozoanLeishmania majorwas targeted as a model system. The crystal structure of TBCA and comparisons with three orthologous proteins are presented. The presence of conserved features infers that electrostatic interactions that are likely to involve the C-terminal tail of β-tubulin are key to association. This study provides a reagent and template to support further work in this area.
Mechanical drilling of PCB micro hole and its application in micro ultrasonic powder molding
Authors: Liang Xiong , Li Bing , Fu Lianyu , Wu Xiaoyu , Shi Hongyan , Peng Taijiang , Xu Bin
Published: April 2015

Purpose

– This paper aims to present the main factors affecting the mechanical drilling of the printed circuit board (PCB for short) micro-holes and method of micro-ultrasonic powder molding (micro-UPM for short) by utilizing PCB micro-hole array.

Design/methodology/approach

– To optimize the drilling process, the paper proposes the on-line monitoring methods for the drilling process including drilling force, drilling temperature, high-speed photography and vibration signals. Taking 0.10 and 0.15 mm micro-drilling as examples, the paper analyzes the drilling process of ultra-small micro-holes. Finally, by taking the PCBs with 0.10 and 0.15 mm micro-hole arrays as the micro-cavity inserts, utilizing ultra-high-molecule weight polyethylene powder with the average particle size of about 150 μm as raw material, two sizes of micro-cylinder array polymer parts are fabricated through micro-UPM process.

Findings

– PCB micro-cavity inserts with micro-hole arrays fabricated by mechanical drilling has the advantages of low costs, high efficiency and good consistency. Taking 0.10 and 0.15 mm micro-drilling as examples, it is found that the both measured apertures are about 10.0 μm more than the diameter of the micro-drill bits on average. The average diameter of the micro-cylinders by micro-UPM process is smaller than that of the micro-hole with the same specification, while the value of the roughness of the cylinder surface is more than that of the hole-wall surface with the same specification.

Originality/value

– This paper describes the challenges and the developments of mechanical drilling and by using PCB micro-cavity inserts with micro-hole arrays fabricated by mechanical drilling, two different micro-cylinder array polymer parts are successfully made and thus the application area of PCB micro-drilling is broadened.
Globalization, technology and the transnational capitalist class
Authors: Harris Jerry
Published: April 2015

Purpose

– The purpose of this paper is to explore how capitalism has developed into a deeply integrative economic system of financial investments and manufacturing. This process of globalization has brought about the emergence of a transnational capitalist class that rules the world’s economy. Financialization, created by the speed and interconnectivity of information technologies, is a key element that has produced immense wealth for a few while reducing their dependence on the labor of workers. This system of global accumulation has lead to a crisis of democracy with several different possible outcomes.

Design/methodology/approach

– This paper begins with an historical examination of capitalism and capitalist class formation by tracing developments from nation-centric capitalism to globalization. A conceptual explanation of the development of the transnational capitalist class (TCC) is offered. Research on current economic data to support the thesis on the emergence of the TCC in both its private and statist forms is included, as well as an examination of the latest technology developments that affect financialization and how this impacts class relations. The conclusion analyzes the development of democracy as a class dialectic, and the impact of globalization that is altering the historic relationships between capital and labor. The paper ends with a discussion of possible political/economic futures.

Findings

– Globalization is a new era in which capitalism has deepened its inherent tendency toward creating world markets and production. This process has been greatly enhanced by the new technological tools of financial production. Organizing and overseeing this system of global accumulation is the transnational capitalist class. The emergence of this class has transformed class relations based within the historic perimeters of nation-states, and it threatens the content and character of democracy that arose out of the bourgeois democratic revolutions in America and France.

Originality/value

– Transnational Capitalist Class Theory is a recently developed field of research. It is a new critic of mainstream international relations analysis which centers on nation to nation relationships. It also differs with world system theory which divides countries into a center/peripheral analysis. Within the field of TCC research, this paper offers an original historic perspective between global economics and the development of democracy. It also makes new theoretical connections between information technology, financialization and the destruction of the social contract.
Bow down all 7 billion: the compressed spheres of global governance
Authors: Ahen Frederick
Published: April 2015

Purpose

– This paper aims to answer two questions: How do technologies of governance explain how global governance is enacted? and What alternatives can be proposed for a sustainable future for the governed 7 billion?

Design/methodology/approach

– Using institutional theory and Galtung’s (1971) structural theory of imperialism as critical theoretical frameworks, this paper confronts orthodox conception of global governance by offering transformative alternatives to inequality, a “historically situated urgency”, which is the product of a faulty global governance system.

Findings

– Concrete, purposively sampled empirical illustrations on transnational corporations’ resource control and how “flight capital” fleeces the poor to enrich the affluent are provided to aid understanding. This helps to explain how such secretive financial mechanisms perpetuate global inequality in health, education and general well-being.

Social implications

– The study introduces the concept of compressed spheres of global governance. It is theorized that diverse institutional logics provide clusters of governors in coopetition that affect individuals and communities of places and communities of interests differently.

Originality/value

– The novelty in this study is the concept of compressed spheres of global governance which explain how both visible and invisible systems shape all the worlds of the governors and the governed, as well as how they both interpret their lived experiences.
Stakeholder differences in the understanding of inter-organizational concept content as a risk factor
Authors: Gajšek Brigita , Rosi Bojan
Published: April 2015

Purpose

– The purpose of this paper is to help clarify understanding of the logistic platform concept so as to release its potential for the benefit of the logistics sector.

Design/methodology/approach

– Cross-sectional research was conducted in Slovenia, Poland and Singapore. Web-based survey responses were obtained from four organization types: logistics companies (LCs); production or service non-LCs; branch associations/state agencies/chambers of commerce; and educational institutions.

Findings

– Logistics platforms (LPFs) are a very much a multi-level phenomenon which, through macro-level organization, may multiply the micro- and meso-level effects obtained. The joint development of promising inter-organizational concepts which involve different stakeholder groups can be inefficient owing to differences in concept content understanding.

Research limitations/implications

– The research was limited to Slovenia, Poland and Singapore. Further research in other countries would be beneficial, and the survey can be repeated for other inter-organizational concepts.

Practical implications

– This paper proposes a general LPF model and seeks to raise awareness of the complexity surrounding the implementation of this particular inter-organizational concept. From the viewpoint of a practitioner, the knowledge that different stakeholder groups may have divergent perceptions of the concept’s content is important and will help strengthen inter-organizational projects by devoting attention to basic fact unification.

Originality/value

– This paper is the first transparent overview on the understanding and utilization of LPFs in theory and practice. The paper proposes a general LPF model. The authors wish to highlight the need for research into the perceptions held among different stakeholder groups regarding the concept’s content for the implementation of inter-organizational projects.
Principals’ leadership behaviour: values-based, contingent or both?
Authors: Warwas Julia
Published: April 2015

Purpose

– Concepts of values-based leadership posit that school principals’ professional practice must be informed by values to ensure coherently purposeful activities. Contingency models stress the contextual dependency of professional practice and the need to match activities to local opportunities and constraints. The purpose of this paper is to reconcile both positions from an integrative perspective and to illustrate examples of “values-based contingency leadership” (Dayet al., 2001).

Design/methodology/approach

– Analyses draw on survey data from 56 German schools in order to relate professional values stated by the principals as well as organizational features of their schools to teacher ratings on leadership behaviour (n=910). Instead of scrutinizing singular variables in isolation, a typological approach serves to identify value profiles as well as organizational configurations. Analyses of variance are applied to examine the combined effects of both factors on leadership behaviour.

Findings

– Interactional effects in the sample indicate that contextual influences are not homogenous across differing value profiles of principals who operate under equal conditions. Descriptive patterns of leadership behaviour within each organizational configuration reveal how principals accentuate leadership activities according to their value profile.

Research limitations/implications

– Due to the low statistical power of the small sample, findings are clearly exploratory in nature. However, replication and extension studies seem fruitful, as effect sizes of value-context interactions are consistent with theoretical assumptions and not artificially inflated by common-source variance.

Originality/value

– This paper elaborates and exemplifies the moderating role of values in contextual influences on leadership behaviour. It also provides deeper insights into the content and structure of professional values advocated by school principals.
Reflections on the evolution of educational leadership preparation programs in the United States and challenges ahead
Authors: McCarthy Martha
Published: April 2015

Purpose

– The purpose of this legacy paper is to review leadership preparation over time in the United States and addresses challenges ahead. It is hoped that the US developments will be instructive to an international audience interested in strengthening the preparation of school leaders.

Design/methodology/approach

– The paper synthesizes research and commentary on leadership preparation programs in the US as a basis for identifying five challenges ahead.

Findings

– Meaningful change should be informed by the past but not bound by tradition. It is imperative to be open to different viewpoints, to take reasonable – and at times bold – risks, and to question deeply held values and assumptions. Broad recognition of the significant role school leaders play in facilitating student learning suggests that the political climate is right to effect meaningful reforms in leadership preparation in the US. Those involved in preparing school leaders are urged to address the challenges identified in this paper.

Research limitations/implications

– Encouraging work is underway, but many more people need to be involved in efforts to rigorously assess and improve leadership preparation.

Practical implications

– We do not have all the answers but cannot be paralyzed by what we do not know. We are ethically responsible to act on what we do know, such as incorporating the compelling research on learning theory into the leadership preparation curriculum.

Originality/value

– The traditional complacency in the educational leadership professoriate cannot continue if university preparation programs are to meet the needs of the next generation of school leaders. The time is short, and the stakes are high for all involved especially for PK-12 students.
Principals’ sensemaking and enactment of teacher evaluation
Authors: Rigby Jessica G.
Published: April 2015

Purpose

– The purpose of this paper is to look across six first-year principals to investigate their engagement with and sensemaking of specific messages of instructional leadership around teacher evaluation.

Design/methodology/approach

– This research project, a cross-case study, was carried out using in-depth qualitative observations and interviews of six first-year principals over one school year. Sensemaking theory was used to analyze both how and the mechanisms through which principals understood their roles as teacher evaluators.

Findings

– The results demonstrate that first, principals received a variety of messages about how to conduct teacher evaluations, and second, that connections to specific individuals influenced their associations to specific messages they received about instructional leadership and how they enacted teacher evaluation practices on their campuses.

Research limitations/implications

– This is an in-depth qualitative analysis, and therefore is not generalizable to all first-year principals, school districts, or principal preparation programs. However, it adds to the field’s understanding of the meso level of policy implementation, highlighting the process of individuals’ sensemaking and the importance of their informal connections in the associations they make to messages about instructional leadership.

Practical implications

– This research adds to the field of principal preparation and induction as it highlights what is important for first-year principals as they build their professional identities. Further, it highlights the variability in principals’ understanding and enactment of teacher evaluation policies, an important feature as this practice is coming to the fore both in current practice and research.

Originality/value

– This study adds to an understanding of institutional theory by looking at the interaction between the organizational levels, and further explicates individual actors’ agency within a socio-organizational context. The findings also add to a dearth of empirical studies on the routine of teacher evaluation from the principal perspective.