bluuebunny/crossref_metadata_2025 huggingface dataset:
Happiness, work engagement and organisational commitment of support staff at a tertiary education institution in South Africa
Authors: Field Lyndsay K. , Buitendach Johanna H.
Published: October 2011

Orientation: Support staff members play a vital role in tertiary education institutions. With this in mind, the institutions must address their particular needs. In the context of positive psychology, issues of happiness and work engagement could lead to increased positive organisational outcomes like the commitment of support staff.Research purpose: The purpose of the research was to determine the relationship between happiness, work engagement and organisational commitment and to determine whether happiness and work engagement hold predictive value for the organisational commitment of support staff.Motivation for the study: This study aims to enable the identification of a link between happiness, work engagement and organisational commitment and to identify a predictive value of the model.Research design, approach and method: The researchers used a cross-sectional survey design. They used a sample of 123 (N = 123) support staff members from a tertiary education institution in South Africa. The researchers used four demographic questionnaires for the research. These were the ‘Satisfaction with Life Scale’ (SWLS), the ‘Well-Being Questionnaire’ (WBQ), the ‘Utrecht Work Engagement Scale’ (UWES) and the ‘Organisational Commitment Questionnaire’ (OCQ).Main findings: The researchers found a significant positive relationship between affective organisational commitment and work engagement, as well as between affective organisational commitment and happiness (as the SWLS and WBQ measure). They found a significant positive relationship between work engagement and happiness. Finally, the results showed that happiness and work engagement have predictive value for affective organisational commitment.Practical/managerial implications: Happiness and work engagement have predictive value for affective organisational commitment. Therefore, institutions should carefully tailor any implementation programme or initiative to address this relationship.Contribution/value-add: The findings will benefit both managers and workers. Institutions should consider evaluating the levels of happiness and work engagement of their support staff to address the issue of the organisational commitment of their employees.
Interface Dynamics and Far-From-Equilibrium Phase Transitions in Multilayer Epitaxial Growth and Erosion on Crystal Surfaces: Continuum Theory Insights
Authors: Golubović Leonardo , Levandovsky Artem , Moldovan Dorel
Published: October 2011

We review recent theoretical progress in the physical understanding of far-from-equilibrium phenomena seen experimentally in epitaxial growth and erosion on crystal surfaces. The formation and dynamics of various interface structures (pyramids, ripples, etc.), and also kinetic phase transitions observed between these structures, can all be understood within a simple continuum model based on the mass conservation law and respecting the symmetries of the growing crystal surface. In particular, theoretical predictions and experimental results are compared for (001), (110) and (111) crystal surfaces.
Distinguishing between the effects of ocean acidification and ocean carbonation in the coccolithophore Emiliania huxleyi
Authors: Bach Lennart Thomas , Riebesell Ulf , Schulz Kai Georg
Published: October 2011

The coccolithophore Emiliania huxleyi was cultured under a broad range of carbonate chemistry conditions to distinguish the effects of individual carbonate system parameters on growth, primary production, and calcification. In the first experiment, alkalinity was kept constant and the fugacity of CO2 (fCO2) varied from 2 to 600 Pa (1 Pa ≈ 10 µatm). In the second experiment, pH was kept constant (pHfree = 8) with fCO2 varying from 4 to 370 Pa. Results of the constant‐alkalinity approach revealed physiological optima for growth, calcification, and organic carbon production at fCO2 values of ~ 20 Pa, ~ 40 Pa, and ~ 80 Pa, respectively. Comparing this with the constant‐pH approach showed that growth and organic carbon production increased similarly from low to intermediate CO2 levels but started to diverge towards higher CO2 levels. In the high CO2 range, growth rates and organic carbon production decreased steadily with declining pH at constant alkalinity while remaining consistently higher at constant pH. This suggests that growth and organic carbon production rates are directly related to CO2 at low (sub‐saturating) concentrations, whereas towards higher CO2 levels they are adversely affected by the associated decrease in pH. A pH dependence at high fCO2 is also indicated for calcification rates, while the key carbonate system parameter determining calcification at low fCO2 remains unclear. These results imply that key metabolic processes in coccolithophores have their optima at different carbonate chemistry conditions and are influenced by different parameters of the carbonate system at both sides of the optimum.
Resting egg production induced by food limitation in the calanoid copepod Acartia tonsa
Authors: Drillet Guillaume , Hansen Benni W. , Kiørboe Thomas
Published: October 2011

Three populations of the copepod Acartia tonsa, two from the Baltic Sea and one from the U.S. East Coast, were compared for resting egg production at conditions of saturating and limiting food availability. All three populations produced eggs that hatched within 72 h when incubated at 17°C (subitaneous eggs), but the two Baltic populations in addition produced eggs that hatched at a much slower rate, in the course of a month (delayed hatching eggs [DHE]). Such eggs were not produced by the U.S. population. The fraction of DHE increased when food was limiting. Females from a Baltic population that were incubated individually all produced subitaneous eggs, but about half the females consistently also produced DHE. Cold storage that mimicked boreal winter conditions synchronized the hatching of DHE after extended storage, indicating that spring hatching of DHE might seed the water column with nauplii as an adaptation to match the timing of the spring bloom in boreal marine ecosystems. Low food availability promotes the production of resting eggs in marine copepods.
Enduring physiological and reproductive benefits of enhanced flow for a stony coral
Authors: Mass Tali , Brickner Itzchak , Hendy Erica , Genin Amatzia
Published: October 2011

We experimentally examined the in situ, long‐term effects of flow on the coral Pocillopora verrucosa over a 2‐yr period. Eighteen coral nubbins were positioned on stages protected from the ambient flow with transparent walls. Six of the corals were exposed to “enhanced flow” with underwater pumps (15‐20 cm s‐1), while another other six were grown under “reduced‐flow” conditions (~ 1 cm s‐1), and a further six nubbins were set up as a control treatment exposed to ambient natural flow conditions on stages without walls. Mortality was 50% in the reduced‐flow experiment. Compared with the reduced‐flow and the control treatments, colonies growing in enhanced‐flow conditions developed a more compact morphology and had significantly higher chlorophyll and protein concentrations, a higher density of zooxanthellae, and, most importantly, higher reproductive output. However, corals grown in reduced‐flow conditions had lower skeleton density compared with those grown under ambient flow or enhanced flow. Flow rate had no measurable influence on average pH at the site of calcification as monitored by skeletal boron isotopic composition (δ11B). Hence, the skeletal δ11B‐pH proxy in this coral appears to be independent of flow and the biological attributes that are modulated by flow, such as zooxanthellae density, chlorophyll concentrations, and rates of photosynthesis, respiration, and calcification. Calcification site pH in all colonies was raised by +0.3 relative to ambient seawater pH. Together with light, flow should be considered a key abiotic factor determining core biological characteristics of P. verrucosa.
Climate variability of the mid- and high-latitudes of the Southern Hemisphere in ensemble simulations from 1500 to 2000 AD
Authors: Wilmes S. B. , Raible C. C. , Stocker T. F.
Published: October 2011

Abstract. To increase the sparse knowledge of long-term Southern Hemisphere (SH) climate variability we assess an ensemble of 4 transient simulations over the last 500 yr performed with a state-of-the-art atmosphere ocean general circulation model. The model is forced with reconstructions of solar irradiance, greenhouse gas (GHG) and volcanic aerosol concentrations. A 1990 control simulation shows that the model is able to represent the Southern Annular Mode (SAM), and to some extent the South Pacific Dipole (SPD) and the Zonal Wave 3 (ZW3). During the past 500 yr we find that SPD and ZW3 variability remain stable, whereas SAM shows a significant shift towards its positive state during the 20th century. Regional temperatures over South America are strongly influenced by changing both GHG concentrations and volcanic eruptions whereas precipitation shows no significant response to the varying external forcing. For temperature this stands in contrast to proxy records suggesting that SH climate is dominated by internal variability rather than external forcing. The underlying dynamics of the temperature changes generally point to a combination of several modes, thus, hampering the possibilities regional reconstructions of the modes from proxy records. The linear imprint of the external forcing is as expected, i.e. a warming for increase in the combined solar and GHG forcing and a cooling after volcanic eruptions. Dynamically only the increase in SAM with increased combined forcing is simulated.
Pliocene Model Intercomparison Project: implementation strategy and mid-Pliocene Global climatology using GENESIS v3.0 GCM
Authors: Koenig S. J. , DeConto R. M. , Pollard D.
Published: October 2011

Abstract. The mid-Pliocene Warm Period (3.29 to 2.97 Ma BP) has been identified as an analogue for the future, with the potential to help understand climate processes in a warmer than modern world. Sets of climate proxies, combined to provide boundary conditions for Global Climate Model (GCM) simulations of the mid-Pliocene, form the basis for the international, data-driven Pliocene Model Intercomparison Project (PlioMIP). Here, we outline the strategy for implementing pre-industrial (modern) and mid-Pliocene forcings and boundary conditions into the GENESIS version 3 GCM, as part of PlioMIP. We describe the prescription of greenhouse gas concentrations and orbital parameters and the implementation of geographic boundary conditions such as land-ice-sea distribution, topography, sea surface temperatures, sea ice extent, vegetation, soils, and ice sheets. We further describe model-specific details including spin-up and integration times. In addition, the global climatology of the mid-Pliocene as simulated by the GENESIS v3 GCM is analyzed and compared to the pre-industrial control simulation. The simulated climate of the mid-Pliocene warm interval is found to differ considerably from pre-industrial. We identify model sensitivity to imposed forcings, and internal feedbacks that collectively affect both local and far-field responses. Our analysis points out the need to assess both the direct impacts of external forcings and the combined effects of indirect, internal feedbacks. This paper provides the basis for assessing model biases within the PlioMIP framework, and will be useful for comparisons with other studies of mid-Pliocene climates.
Peace Psychology: Definitions, Scope, and Impact
Authors: Christie Daniel J.
Published: October 2011

Although peace psychology has deep roots in philosophy, peace psychology did not take shape as a coherent area of interest until the second half of the twentieth century. Since then, the growth has been remarkable. InPeace Psychology: A Comprehensive Introduction, Blumberg (2007) examined trends in citations to peace psychology using the PsycINFO database and found a large, significant increase in citations between the 1970s and 1980s, and again after the 1990s. These increases were in absolute terms as well as in proportion to the growing number of records. In the current article, some definitions of peace psychology that attempt to delineate the scope of this emerging field are offered. Then, peace psychology is situated in various geohistorical contexts around the world, and finally, some contributions of peace psychology to peace will be discussed.
Tribal Warfare
Authors: FERGUSON R. BRIAN
Published: October 2011

Tribes, broadly defined, are indigenous peoples outside the direct administration of a centralized, authoritative, state. Applied to the great diversity of tribal groupings, war must also be defined very broadly, as organized, deadly violence by members of one group against members of another. Tribal warfare is known to us through archaeological recovery, observers from ancient states, reports of explorers and colonialists since the era of Columbus, and systematic study by cultural anthropologists beginning in the early twentieth century. Earlier writers often conceptualized “primitive war” as qualitatively distinct from “civilized” or “true” war – either more fanatical or more game‐like, and not adhering to proven military principles. More recent scholars have stressed the essential similarity of war by state and non‐state peoples.
Supramolecular Order of Solution‐Processed Perylenediimide Thin Films: High‐Performance Small‐Channel n‐Type Organic Transistors
Authors: Fabiano Simone , Wang He , Piliego Claudia , Jaye Cherno , Fischer Daniel A. , Chen Zhihua , Pignataro Bruno , Facchetti Antonio , Loo Yueh‐Lin , Loi Maria Antonietta
Published: October 2011

N,N′‐1H,1H‐perfluorobutyl dicyanoperylenecarboxydiimide (PDIF‐CN2), a soluble and air stable n‐type molecule, undergoes significant reorganization upon thermal annealing after solution deposition on several substrates with different surface energies. Interestingly, this system exhibits an exceptional edge‐on orientation regardless of the substrate chemistry. This preferential orientation is rationalized in terms of strong intermolecular interactions between the PDIF‐CN2 molecules. The presence of a pronounced π–π stacking is confirmed by combining near‐edge X‐ray absorption fine structure spectroscopy (NEXAFS), dynamic scanning force microscopy (SFM) and surface energy measurements. The remarkable charge carrier mobility measured in field‐effect transistors, using both bottom‐ and top‐contact (bottom‐gate) configurations, underlines the importance of strong intermolecular interactions for the realization of high performing devices.
Multiscale Modeling of Composite Materials: a Roadmap Towards Virtual Testing
Authors: LLorca J. , González C. , Molina‐Aldareguía J. M. , Segurado J. , Seltzer R. , Sket F. , Rodríguez M. , Sádaba S. , Muñoz R. , Canal L. P.
Published: October 2011

A bottom‐up, multiscale modeling approach is presented to carry out high‐fidelity virtual mechanical tests of composite materials and structures. The strategy begins with the in situ measurement of the matrix and interface mechanical properties at the nanometer‐micrometer range to build up a ladder of the numerical simulations, which take into account the relevant deformation and failure mechanisms at different length scales relevant to individual plies, laminates and components. The main features of each simulation step and the information transferred between length scales are described in detail as well as the current limitations and the areas for further development. Finally, the roadmap for the extension of the current strategy to include functional properties and processing into the simulation scheme is delineated.
A broad range of ophthalmologic anomalies is part of the holoprosencephaly spectrum
Authors: Pineda‐Alvarez Daniel E. , Solomon Benjamin D. , Roessler Erich , Balog Joan Z. , Hadley Donald W. , Zein Wadih M. , Hadsall Casey K. , Brooks Brian P. , Muenke Maximilian
Published: October 2011

Holoprosencephaly (HPE) is the most common disorder of the developing forebrain in humans, and is characterized by failed or incomplete cleavage of the cerebral hemispheres and deep brain structures. HPE includes wide phenotypic variability, with a continuum of both brain and craniofacial anomalies. While “classic” eye findings, including the spectrum of midline anomalies ranging from cyclopia to hypotelorism, as well as chorioretinal coloboma and microphthalmia, have been frequently described in patients with HPE, other subtle eye anomalies may also occur. In our study we prospectively analyzed a small cohort of 10 patients in whom we identified mutations in SHH, SIX3, ZIC2, or FGF8, the latter of which is a very recently described HPE‐associated gene. We found that 9 of 10 patients had at least two ophthalmologic anomalies, including refractive errors, microcornea, microphthalmia, blepharoptosis, exotropia, and uveal coloboma. These findings contribute to the understanding of the phenotypic variability of the HPE spectrum, and highlight findings in one medically important but often incompletely investigated system. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.
Neonatal intensive care unit stress is associated with brain development in preterm infants
Authors: Smith Gillian C. , Gutovich Jordan , Smyser Christopher , Pineda Roberta , Newnham Carol , Tjoeng Tiong H. , Vavasseur Claudine , Wallendorf Michael , Neil Jeffrey , Inder Terrie
Published: October 2011

Objective:

Although many perinatal factors have been linked to adverse neurodevelopmental outcomes in very premature infants, much of the variation in outcome remains unexplained. The impact on brain development of 1 potential factor, exposure to stressors in the neonatal intensive care unit, has not yet been studied in a systematic, prospective manner.

Methods:

In this prospective cohort study of infants born at <30 weeks gestation, nurses were trained in recording procedures and cares. These recordings were used to derive Neonatal Infant Stressor Scale scores, which were employed to measure exposure to stressors. Magnetic resonance imaging (brain metrics, diffusion, and functional magnetic resonance imaging) and neurobehavioral examinations at term equivalent postmenstrual age were used to assess cerebral structure and function. Simple and partial correlations corrected for confounders, including immaturity and severity of illness, were used to explore these relations.

Results:

Exposure to stressors was highly variable, both between infants and throughout a single infant's hospital course. Exposure to a greater number of stressors was associated with decreased frontal and parietal brain width, altered diffusion measures and functional connectivity in the temporal lobes, and abnormalities in motor behavior on neurobehavioral examination.

Interpretation:

Exposure to stressors in the Neonatal Intensive Care Unit is associated with regional alterations in brain structure and function. Further research into interventions that may decrease or mitigate exposure to stressors in the neonatal intensive care unit is warranted. ANN NEUROL 2011;
Polymerization shrinkage/stress and dentin bond strength of silorane and dimethacrylate‐based dental composites
Authors: Li Yuncong , Sun Xiang , Chen Jihua , Xiong Jie , Hu Xiaoyi
Published: October 2011

This study was designed to determine whether a new dedicated adhesive system using a silorane composite exhibits better bonding performance to human dentin than conventional dimethacrylate‐based composites. The materials were used included: Adper™ Easy Bond‐Z250 (AE‐Z250), iBond‐Venus (IB‐VE), XenoIII‐TPH (XE‐TPH), Clearfil S3‐Clearfil Majesty (S3‐CM), and the Filtek silorane system (SA‐FS). Polymerization volumetric shrinkage and stress development were measured using a micro‐CT instrument and universal testing machine. The push out strength of the bonds produced using the corresponding self‐etching adhesive systems were also measured. The volumetric shrinkage of the resin composite/adhesive combinations ranged from 1.05% (SA‐FS) to 3.38% (XE‐TPH) 30 min after light curing. SA‐FS had the lowest volumetric shrinkage (P < 0.05), followed by S3‐CM, EA‐Z250, IB‐VE, and XE‐TPH. The polymerization stress of the materials ranged from 1.54 (SA‐FS) to 3.49 MPa (S3‐CM). The lowest stress was also observed in SA‐FS at 30 min during the stress test (P < 0.05). Push‐out bond strength testing revealed that IB‐VE had significantly lower bond strength than other combinations (P < 0.05). The silorane composite and dedicated adhesive system exhibited excellent characteristics of low volumetric shrinkage and stress development compared to conventional dimethacrylate‐based composites. However, the silorane composite resin system possessed similar push‐out bond strength as the other materials, with the exception of the Venus/iBond combination. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and evaluation of nano‐epoxy composite resins containing electrospun glass nanofibers
Authors: Chen Qi , Zhang Lifeng , Yoon Myung‐Keun , Wu Xiang‐Fa , Arefin Ragib H. , Fong Hao
Published: October 2011

In this study, electrospun glass (structurally amorphous SiO2) nanofibers (EGNFs) with diameters of ∼ 400 nm were incorporated into epoxy resin for reinforcement and/or toughening purposes; the effects of silanization treatment (including different functional groups in silane molecules) and mass fraction of EGNFs on strength, stiffness, and toughness of the resulting nano‐epoxy composite resins were investigated. The experimental results revealed that EGNFs substantially outperformed conventional glass fibers (CGFs, with diameters of ∼ 10 μm) in both tension and impact tests, and led to the same trend of improvements in strength, stiffness, and toughness at small mass fractions of 0.5 and 1%. The tensile strength, Young's modulus, work of fracture, and impact strength of the nano‐epoxy composite resins with EGNFs were improved by up to 40, 201, 67, and 363%, respectively. In general, the silanized EGNFs with epoxy end groups (G‐EGNFs) showed a higher degree of toughening effect, while the silanized EGNFs with amine end groups (A‐EGNFs) showed a higher degree of reinforcement effect. The study suggested that electrospun glass nanofibers could be used as reinforcement and/or toughening agent for making innovative nano‐epoxy composite resins, which would be further used for the development of high‐performance polymer composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The Dorsal Sagittal Venous Sinus Anatomical Variations in Brachycephalic, Dolichocephalic, and Mesocephalic Dogs and Their Significance for Brain Surgery
Authors: Carreira L. Miguel , Ferreira António , Burilo Fernando Liste
Published: October 2011

Dorsal sagittal venous sinus (DSVS) is an encephalic structure located in the midline of brain dorsal surface, starting behind the frontal venous sinus and following the brain falx in its extension. Knowing DSVS morphology and cranial‐cerebral relationships it is very important for surgeon when he is planning the placement of craniotomies, in order to prevent the damage of this structure. The main purpose of this study were to establish craniometric points that can be used as key points of neurosurgical importance providing an anatomic framework to brain access regarding the localization of DSVS, and to characterize the morphology of DSVS in the three groups considered in study according their type of skull (brachycephalic‐B, dolychocephalic‐D and mesocephalic‐M). The study was performed on 138 formalin‐fixed cerebral hemispheres of 69 adult dog cadavers (23 of each group) which had been removed from the skulls after the introduction of plastic catheters through properly positioned burr holes placed on the five craniometric points considered: asterion(ast), bregma(br), glabella(g), stephanion(st) and pterion(pt). From the three groups, DSVS length and width were different, his geometry in B assumed a triangular appearance and in D, M a “butterfly” shape. From all craniometric points considered, only bregma (br) can be useful as a landmark to delimitate DSVS morphology in all three groups. Asterion in M, stephanion in B, glabella and pterion in all three groups, can not be used to compose a framework that help to understand skull surface projection of DSVS morphology, since their measurements were not uniform. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Decreased Cytochrome c Oxidase Subunit VIIa in Aged Rat Heart Mitochondria: Immunocytochemistry
Authors: Fujioka Hisashi , Moghaddas Shadi , Murdock Deborah G. , Lesnefsky Edward J. , Tandler Bernard , Hoppel Charles L.
Published: October 2011

Aging decreases oxidative phosphorylation through cytochrome oxidase (COX) in cardiac interfibrillar mitochondria (IFM) in 24‐month old (aged) rats compared to 6‐month old adult Fischer 344 rats, whereas subsarcolemmal mitochondria (SSM) located beneath the plasma membrane remain unaffected. Immunoelectron microscopy (IEM) reveals in aged rats a 25% reduction in cardiac COX subunit VIIa in cardiac IFM, but not in SSM. In contrast, the content of subunit IV remains unchanged in both SSM and IFM, irrespective of age. These subunits are localized mainly on cristae membranes. In contrast, semi‐quantitative immunoblotting, which detects denatured protein, indicates that the content of COX VIIa is similar in IFM and SSM from both aged and adult hearts. IEM provides a sensitive method for precise localizing and quantifying specific mitochondrial proteins. The lack of immunoreaction of COX VIIa subunit by IEM in aged IFM is not explained by a reduction in protein, but rather by a masking phenomenon or by an in situ change in protein structure affecting COX activity. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Problems and Solutions with GPR Data Interpretation: Depolarization and Data Continuity
Authors: Leckebusch Jürg
Published: October 2011

When interpreting large area ground‐penetrating radar (GPR) surveys it has been found that the depolarization of electromagnetic waves affects the reflectivity of some subsurface features, which has a larger effect on detectability than previously thought. This depolarization can make some archaeological structures almost invisible using standard processing steps including reflection profiles and energy slice maps. Only recording data with orthogonal antenna orientation will eliminate this problem. After three‐dimensional interpretation of three‐dimensional volumes of GPR reflections a variable width gap between floors and their bounding walls has been repeatedly observed. This newly detected problem is clearly visible in a number of surveys conducted at a Roman town in Switzerland. It is explained by the distorted geometry of the sides of the floors common in the Roman Empire, resulting in a reflection surface that reflects most energy away from the surface antennae and only limited energy is recorded, making portions of the floors invisible. Copyright © 2011 John Wiley & Sons, Ltd.
Internal supravesical hernia: An unusual cause of small bowel obstruction
Authors: Schwarz L. , Moszkowicz D. , Peschaud F. , Keilani K. , Michot F. , Scotté M.
Published: October 2011

Internal hernia of the supravesical fossa is an unusual cause of small bowel obstruction. We report the case of a patient without previous abdominal surgery with an acute abdominal obstruction in which laparoscopic exploration revealed a strangulated internal supravesical hernia. To help clinicians with their pre‐operative diagnosis and to better understand the clinical management of this unusual internal hernia, a description of the anatomy of the supravesical fossa is included in this case report. Clin. Anat. 25:663–667, 2012. © 2011 Wiley Periodicals, Inc.
fac‐[TcO3(tacn)]+: A Versatile Precursor for the Labelling of Pharmacophores, Amino Acids and Carbohydrates through a New Ligand‐Centred Labelling Strategy
Authors: Braband Henrik , Tooyama Yuji , Fox Thomas , Simms Ryan , Forbes John , Valliant John F. , Alberto Roger
Published: October 2011

Herein, we report a protocol for the synthesis of [99mTcO3(tacn)]+ ([1]+) (tacn=1,4,7‐triazacyclononane) that is suitable for clinical translation. Bioconjugates containing pharmacophores ([TcO(NO2‐Imi)(tacn)]+; [3]+), artificial amino acids ([TcO(Fmoc‐allyl‐His)(tacn)]+; [5]+), and glucose derivatives ([TcO(allyl‐tetraacetylglucose)(tacn)]+; [7]+) were synthesized by cycloaddition strategies and fully characterized (99Tc and 99mTc). These new technetium complexes are stable at neutral pH and demonstrate the potential and flexibility of the [3+2] cycloaddition labelling concept. In addition to the synthetic work, the first biodistribution studies of [1]+ and the small [3+2] cycloadduct [99mTcO(NO2‐Imi)(tacn)]+ ([3]+) were completed. The biodistribution studies suggest the stability of these complexes in vivo. Furthermore, it was demonstrated that the high hydrophilicity of the [99mTcO3(tacn)]+ building block is a complement to the complexes of the fac‐{Tc(CO)3}+ core.
Why is RCM Favoured Over Dimerisation? Predicting and Estimating Thermodynamic Effective Molarities by Solution Experiments and Electronic Structure Calculations
Authors: Nelson David J. , Ashworth Ian W. , Hillier Ian H. , Kyne Sara H. , Pandian Shanthi , Parkinson John A. , Percy Jonathan M. , Rinaudo Giuseppe , Vincent Mark A.
Published: October 2011

The thermodynamic effective molarities of a series of simple cycloalkenes, synthesised from α,ω‐dienes by reaction with Grubbs’ second generation precatalyst, have been evaluated. Effective molarities were measured from a series of small scale metathesis reactions and agreed well with empirical predictions derived from the number of rotors and the product ring strain. The use of electronic structure calculations (at the M06‐L/6‐311G** level of theory) was explored for predicting thermodynamic effective molarities in ring‐closing metathesis. However, it was found that it was necessary to apply a correction to DFT‐derived free energies to account for the entropic effects of solvation.
A Ring‐Closing Metathesis (RCM)‐Based Approach to Mycolactones A/B
Authors: Gersbach Philipp , Jantsch Andrea , Feyen Fabian , Scherr Nicole , Dangy Jean‐Pierre , Pluschke Gerd , Altmann Karl‐Heinz
Published: October 2011

The total synthesis of the mycobacterial toxins mycolactones A/B (1 a/b) has been accomplished based on a strategy built around the construction of the mycolactone core through ring‐closing metathesis. By employing the Grubbs second‐generation catalyst, the 12‐membered core macrocycle of mycolactones, with a functionalized C2 handle attached to C11, was obtained in 60–80 % yield. The C‐linked upper side chain (comprising C12–C20) was completed by a highly efficient modified Suzuki coupling between C13 and C14, while the attachment of the C5‐O‐linked polyunsaturated acyl side chain was achieved by Yamaguchi esterification. Surprisingly, a diene containing a simple isopropyl group attached to C11 could not be induced to undergo ring‐closing metathesis. By employing fluorescence microscopy and flow cytometry techniques, the synthetic mycolactones A/B (1 a/b) were demonstrated to display similar apoptosis‐inducing and cytopathic effects as mycolactones A/B extracted from Mycobacterium ulcerans. In contrast, a simplified analogue with truncated upper and lower side chains was found to be inactive.
An auction‐based MAC protocol for cognitive radio networks
Authors: Song Hua , Lin Xiao‐La
Published: October 2011

Cognitive radio and dynamic spectrum sharing systems use innovative spectrum management techniques that allow different systems to share the same frequency band to utilize the radio spectrum in an efficient way. In this paper, we propose a novel cognitive media access control protocol for cognitive radio networks under the property‐rights model, in which secondary users are divided into several nonoverlapping groups, and each group uses the proposed auction algorithm to bid for required channels from the auctioneer appointed by primary users. Simulations indicate that our proposed media access control protocol can effectively utilize spectrum resources, achieve high system efficiency, and guarantee the fairness of channel allocation among groups. Copyright © 2011 John Wiley & Sons, Ltd.
Hindered submicron mobility and long‐term storage of presynaptic dense‐core granules revealed by single‐particle tracking
Authors: Scalettar B.A. , Jacobs C. , Fulwiler A. , Prahl L. , Simon A. , Hilken L. , Lochner J.E.
Published: October 2011

Dense‐core granules (DCGs) are organelles found in neuroendocrine cells and neurons that house, transport, and release a number of important peptides and proteins. In neurons, DCG cargo can include the secreted neuromodulatory proteins tissue plasminogen activator (tPA) and/or brain‐derived neurotrophic factor (BDNF), which play a key role in modulating synaptic efficacy in the hippocampus. This function has spurred interest in DCGs that localize to synaptic contacts between hippocampal neurons, and several studies recently have established that DCGs localize to, and undergo regulated exocytosis from, postsynaptic sites. To complement this work, we have studied presynaptically localized DCGs in hippocampal neurons, which are much more poorly understood than their postsynaptic analogs. Moreover, to enhance relevance, we visualized DCGs via fluorescence labeling of exogenous and endogenous tPA and BDNF. Using single‐particle tracking, we determined trajectories of more than 150 presynaptically localized DCGs. These trajectories reveal that mobility of DCGs in presynaptic boutons is highly hindered and that storage is long‐lived. We also computed mean‐squared displacement curves, which can be used to elucidate mechanisms of transport. Over shorter time windows, most curves are linear, demonstrating that DCG transport in boutons is driven predominantly by diffusion. The remaining curves plateau with time, consistent with motion constrained by a submicron‐sized corral. These results have relevance to recent models of presynaptic organization and to recent hypotheses about DCG cargo function. The results also provide estimates for transit times to the presynaptic plasma membrane that are consistent with measured times for onset of neurotrophin release from synaptically localized DCGs. © 2011 Wiley Periodicals, Inc. Develop Neurobiol, 2012
Primary cilia and Gli3 activity regulate cerebral cortical size
Authors: Wilson Sandra L. , Wilson John P. , Wang Chengbing , Wang Baolin , McConnell Susan K.
Published: October 2011

During neural development patterning, neurogenesis, and overall growth are highly regulated and coordinated between different brain regions. Here, we show that primary cilia and the regulation of Gli activity are necessary for the normal expansion of the cerebral cortex. We show that loss of Kif3a, an important functional component of primary cilia, leads to the degeneration of primary cilia, marked overgrowth of the cortex, and altered cell cycle kinetics within cortical progenitors. The G1 phase of the cell cycle is shortened through a mechanism likely involving reduced Gli3 activity and a resulting increase in expression of cyclin D1 and Fgf15. The defects in Gli3 activity alone are sufficient to accelerate cell cycle kinetics and cause the molecular changes seen in brains that lack cilia. Finally, we show that levels of full‐length and repressor Gli3 proteins are tightly regulated during normal development and correlate with changes in expression of two known Shh‐target genes, CyclinD1 and Fgf15, and with the normal lengthening of the cell cycle during corticogenesis. These data suggest that Gli3 activity is regulated through the primary cilium to control cell cycle length in the cortex and thus determine cortical size. © 2011 Wiley Periodicals, Inc. Develop Neurobiol, 2012
Generation of Rab‐based transgenic lines for in vivo studies of endosome biology in zebrafish
Authors: Clark Brian S. , Winter Mark , Cohen Andrew R. , Link Brian A.
Published: October 2011

The Rab family of small GTPases function as molecular switches regulating membrane and protein trafficking. Individual Rab isoforms define and are required for specific endosomal compartments. To facilitate in vivo investigation of specific Rab proteins, and endosome biology in general, we have generated transgenic zebrafish lines to mark and manipulate Rab proteins. We also developed software to track and quantify endosome dynamics within time‐lapse movies. The established transgenic lines ubiquitously express EGFP fusions of Rab5c (early endosomes), Rab11a (recycling endosomes), and Rab7 (late endosomes) to study localization and dynamics during development. Additionally, we generated UAS‐based transgenic lines expressing constitutive active (CA) and dominant‐negative (DN) versions for each of these Rab proteins. Predicted localization and functional consequences for each line were verified through a variety of assays, including lipophilic dye uptake and Crumbs2a localization. In summary, we have established a toolset for in vivo analyses of endosome dynamics and functions. Developmental Dynamics 240:2452–2465, 2011. © 2011 Wiley Periodicals, Inc.
Deficient CCR7 signaling promotes TH2 polarization and B‐cell activation in vivo
Authors: Moschovakis G. L. , Bubke Anja , Dittrich‐Breiholz Oliver , Braun Asolina , Prinz Immo , Kremmer Elisabeth , Förster Reinhold
Published: October 2011

The chemokine receptor CCR7 has a central role in regulating homing and positioning of T cells and DCs to lymph nodes (LNs) and participates in T‐cell development and activation. In this study, we addressed the role of CCR7 signaling in TH2 polarization and B‐cell activation. We provide evidence that the lack of CCR7 drives the capacity of naïve CD4+T cells to polarize toward TH2 cells. This propensity contributes to a lymph node environment in CCR7‐deficent mice characterized by increased expression of IL‐4 and increased frequency of TH2 cells. We show that elevated IL‐4 levels lead to B‐cell activation characterized by up‐regulated expression of MHC class II, CD23 and CD86. Activated B cells are in turn highly efficient in presenting antigen to CD4+T cells and thus potentially contribute to the TH2 microenvironment. Taken together, our results support the idea of a CCR7‐dependent patterning of TH2 responses, with absent CCR7 signaling favoring TH2 polarization, dislocation of T helper cells into the B‐cell follicles and, as a consequence, B‐cell activation.
DOCK8 is essential for T‐cell survival and the maintenance of CD8+ T‐cell memory
Authors: Lambe Teresa , Crawford Greg , Johnson Andy L. , Crockford Tanya L. , Bouriez‐Jones Tiphaine , Smyth Aisling M. , Pham Trung H. M. , Zhang Qian , Freeman Alexandra F. , Cyster Jason G. , Su Helen C. , Cornall Richard J.
Published: October 2011

Deficiency in the guanine nucleotide exchange factor dedicator of cytokinesis 8 (DOCK8) causes a human immunodeficiency syndrome associated with recurrent sinopulmonary and viral infections. We have recently identified a DOCK8‐deficient mouse strain, carrying an ethylnitrosourea‐induced splice‐site mutation that shows a failure to mature a humoral immune response due to the loss of germinal centre B cells. In this study, we turned to T‐cell immunity to investigate further the human immunodeficiency syndrome and its association with decreased peripheral CD4+ and CD8+ T cells. Characterisation of the DOCK8‐deficient mouse revealed T‐cell lymphopenia, with increased T‐cell turnover and decreased survival. Egress of mature CD4+ thymocytes was reduced with increased migration of these cells to the chemokine CXCL12. However, despite the two‐fold reduction in peripheral naïve T cells, the DOCK8‐deficient mice generated a normal primary CD8+ immune response and were able to survive acute influenza virus infection. The limiting effect of DOCK8 was in the normal survival of CD8+ memory T cells after infection. These findings help to explain why DOCK8‐deficient patients are susceptible to recurrent infections and provide new insights into how T‐cell memory is sustained.
Influence of Zataria multiflora Boiss. essential oil on oxidative stability of sunflower oil
Authors: Hashemi Mohammad Bagher , Niakousari Mehrdad , Saharkhiz Mohammad Jamal , Eskandari Mohammad Hadi
Published: October 2011

In this study, the influence of the application of 0.025%, 0.05% and 0.075% of Zataria multiflora Boiss. essential oil (EO) on oxidative stability of sunflower oil was examined and the EO was compared to butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) during storage at 37°C and 47°C. The main components of EO were identified as carvacrol (45.6%), p‐cymene (18.1%) and thymol (16.3%). Peroxide value (PV), anisidine value (AnV) and thiobarbituric acid (TBA) value measurement in sunflower oil showed that all concentrations of EO had a lower antioxidant effect in comparison to BHA and BHT. Samples supplemented with EO concentration of 0.075% were the most stable during storage at both temperatures (p<0.05). Furthermore, Totox value, antioxidant activity (AA), stabilization factor (F) and antioxidant power (AOP) determination confirmed efficacy of this EO as antioxidant in sunflower oil. EO also was able to reduce the stable 2,2‐diphenyl‐1‐picrylhydrazyl free radical (DPPH.) with a 50% inhibition concentration (IC50) of 34.3 ± 0.8 µg/mL. The results indicate that EO could be used as a natural antioxidant in oils for food uses.
Self‐judgment and reputation monitoring as a function of the fundamental dimensions, temporal perspective, and culture
Authors: Ybarra Oscar , Park Hyekyung , Stanik Christine , Lee David Seungjae
Published: October 2011

Social acceptance and the development of one's competencies and status are fundamental aspects of the human experience, but the former (communion) should take precedence over the latter (agency) in self‐judgment. Study 1 results indicated that (i) people across two cultures judged themselves as possessing higher communion than agency characteristics; (ii) communion self‐judgments were more consistent across temporal perspective; and (iii) level of self‐enhancement across cultures was similar for communion but different for agency. In Study 2, people across culture reported being more troubled and demonstrated a greater desire to repair their reputation when they imagined others perceived them as lacking in communion compared with agency. These findings support the idea that social life pressures people to view themselves as possessing communion traits and to ensure that others have this perception as well. Copyright © 2011 John Wiley & Sons, Ltd.
Perceptions of non‐target confronters in response to racist and heterosexist remarks
Authors: Dickter Cheryl L. , Kittel Julie A. , Gyurovski Ivo I.
Published: October 2011

Research has established that targets who express disagreement with prejudicial comments directed toward their social group may be viewed negatively by those they confront or by members of social outgroups. Less research has examined how non‐target individuals who confront prejudicial remarks are perceived. The current studies were designed to examine how non‐targets who confronted racist (Study 1) and heterosexist (Study 2) comments would be perceived as a function of the level of offensiveness of the comment and the confrontation style used. The studies also examined whether confronting behavior would affect perceptions of the individual who made the prejudicial comment. Undergraduate participants read vignettes depicting a situation with a high or low offensive prejudicial comment in which a non‐target individual confronted assertively, unassertively, or not at all. Participants provided judgments of both individuals. Results indicated that non‐targets who confronted highly prejudicial comments either assertively or unassertively were liked and respected more than those who failed to confront. Additionally, commenters who were assertively confronted were respected less than commenters who were not. These findings suggest that non‐targets may be especially effective in confronting prejudicial comments, as they do not suffer the same negative consequences as targets who confront. Copyright © 2011 John Wiley & Sons, Ltd.
Surface modification of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) copolymer films for promoting interaction with bladder urothelial cells
Authors: García‐García José M. , López Laura , París Rodrigo , Núñez‐López María Teresa , Quijada‐Garrido Isabel , de la Peña Zarzuelo Enrique , Garrido Leoncio
Published: October 2011

Often bladder dysfunction and diseases lead to therapeutic interventions that require partial or complete replacement of damaged tissue. For this reason, the development of biomaterials to repair the bladder by promoting the adhesion and growth of urothelial cells is of interest. With this aim, a modified copolyester of biocompatible and biodegradable poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) [P(HB‐co‐HV)] was used as scaffold for porcine urothelial cell culture. In addition to good biocompatibility, the surface of P(HB‐co‐HV) substrates was modified to provide both, higher hydrophilicity and a better interaction with urothelial cells. Chemical treatments with ethylenediamine (ED) and sodium hydroxide (NaOH) led to substrate surfaces with decreasing hydrophobicity and provided functional groups that enable the grafting of bioactive molecules, such as a laminin derived YIGSR sequence. Physico‐chemical properties of modified substrates were studied and compared with those of the pristine P(HB‐co‐HV). Urothelial cell morphology on treated substrates was studied. The results showed that focal attachment and cell‐related properties were improved for peptide grafted polymer compared with both, the unmodified and functionalized copolyester. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Mediation of the migration of endothelial cells and fibroblasts on polyurethane nanocomposites by the activation of integrin‐focal adhesion kinase signaling
Authors: Hung Huey‐Shan , Chu Mei‐Yun , Lin Chien‐Hsun , Wu Chia‐Ching , Hsu Shan‐hui
Published: October 2011

Model surfaces of polyurethane‐gold nanocomposites (PU‐Au) were used to examine cell behavior on nanophase‐segregated materials. Previously we showed that endothelial cell (EC) migration on these materials was modulated by the PI3K/Akt/eNOS pathway. The present study, investigated the expressions of alpha5/beta3 (α5β3) integrin, focal adhesion kinase (FAK), and other downstream signal molecules such as the Rho family and matrix metalloproteinases 2 (MMP‐2) induced by the materials in two different cells, that is bovine arterial endothelial cells (BAEC) and human skin fibroblasts (HSF). Both cells proliferated better on the more phase‐separated PU‐Au 43.5 ppm than on the less phase‐separated controls (PU and PU‐Au 174 ppm). On PU‐Au 43.5 ppm, BAEC compared to HSF had denser actin fibers and were more extended. BAEC became rounded with Y‐27632 treatment and shrunk with LY294002 treatment. Treatment by inhibitors only caused slight changes in HSF. The migration distance of BAEC on PU‐Au 43.5 ppm was greater than that of HSF, and was significantly reduced by LY294002 or Y‐27632 but not SU‐1498. The expressions of p‐FAK, p‐RhoA, p‐Rac/Cdc42, MMP2, and α5β3 integrin induced by PU‐Au 43.5 ppm were more pronounced in BAEC versus HSF. Further enhancement in MMP2 and α5β3 integrin expressions by FAK‐GFP transfection was more remarkable for cells on PU‐Au 43.5 ppm. Our findings suggested that the integrin α5β3/FAK pathway may be induced by nanophase‐separated materials in both ECs and fibroblasts to promote their proliferation/migration, while the crosstalk between the PI3K/Akt/eNOS pathway and FAK/Rho‐GTPase activation may account for the greater effect in ECs than in fibroblasts. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.