bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of a novel sieving matrix of poly(vinyl alcohol)/acrylamide copolymer in electrophoretic separations of high molecular weight proteins from red cell membrane
Authors: Matte Alessandro , Sola Laura , Chiari Marcella , Tomelleri Carlo , Consonni Roberto , Turrini Franco , Franceschi Lucia De
Published: December 2013

The analysis of high molecular weight (HMW) proteins from complex mixtures is still a challenge in proteomics. This work introduces a novel hydrogel obtained by the copolymerization of an allyl‐PVA derivative with acrylamide and bisacrylamide and applies this matrix to the electrophoretic separation of HMW proteins. By inducing gelation of polyacrylamide in the presence of variable amounts of allyl‐PVA, it is possible to control and vary the average gel porosity. This gel is easy to produce and handle and offers the advantage of being highly mechanically resistant and macroporous. The new matrix was tested in mono‐dimensional separations of complex protein mixtures extracted from red cell membranes with different detergents. The improved performance of this macroporous matrix allowed to identify new proteins by MS and immunoblot analysis using specific antibodies. In particular, the resolution of proteins ranging in size between 97 and 279 kDa was greatly improved here compared to standard polyacrylamide gels, suggesting that this matrix can be a useful tool in routine analysis of HMW proteins in cell biology.
Optimising data placement and traffic routing for energy saving in Backbone Networks
Authors: Fang Weiwei , Wang Zishuo , LIoret Jaime , Zhang Daqiang , Yang Zhijun
Published: December 2013

The energy consumption of network elements has become a big concern due to the exponential traffic growth and the rapid expansion of communication infrastructures. To deal with this problem, we propose a new approach called Backbone network Energy Saving based on Traffic engineering (BEST), which reduces the power consumption of network elements at the backbone level through jointly optimising data placement and traffic routing. Based on analysis on traffic characteristics, BEST firstly optimises the placement of data services such that the pairwise traffic demands can be better coordinated with the pairwise network costs, in order to minimise the traffic burden imposed on the network elements. Then, BEST optimises the routing of traffic flows and tries to find the minimum‐power network subset that must remain active to fulfill the traffic requirements. Efficient heuristics are given by BEST to find an admissible solution when the problem size is very large. The simulation results illustrate the efficacy and efficiency of BEST in energy conservation on backbone networks. Copyright © 2013 John Wiley & Sons, Ltd.
Research on seismic resistance and mechanic behavior of reinforced lightweight aggregate concrete walls after high temperature
Authors: Chi Jen‐Hao , Tang Jun‐Ren , Go Cheer‐Germ , Huang Yue‐Lin
Published: December 2013

This study focused on the mechanical behavior of reinforced lightweight aggregate concrete (RLAC) walls under repeated horizontal loads after a standard temperature‐rising fire‐resistance test and compared the specimen walls' ultimate loads, yielding loads, cracked loads, stiffness, and ductility with those of reinforced normal‐weight aggregate concrete (RNAC) walls. Steel reinforcing bar spacing, aggregate types, wall widths, and high temperatures were variables in this study. The experimental results showed that, after the fire‐resistance test, the smaller the steel reinforcing bar spacing of RLAC walls, the higher the yield and ultimate loads, yet the worse the ductility and the hysteresis loop's energy, whereas the greater the width of the wall, the greater the stiffness and the higher the hysteresis loop's energy. The differences in terms of stiffness, ductility, and hysteresis between RLAC walls with and without the fire‐resistance test were insignificant, indicating that RLAC walls do not lose their basic mechanical behavior during a high‐temperature fire. RNAC walls showed, indeed, a significant downward trend for strength and hysteresis after the fire‐resistance test, but the decrease was much less clear for stiffness. Therefore, RLAC walls did show better seismic resistance than RNAC walls under the same testing conditions. Copyright © 2013 John Wiley & Sons, Ltd.
Petrological and geochemical interpretation of Triassic–Jurassic boundary sections from northern Iraq
Authors: Al‐Juboury Ali I. , McCann Tom
Published: December 2013

Triassic–Jurassic sedimentary successions (Baluti and Sarki formations) in northern Iraq record a variety of environmental changes that may be related to global Triassic–Jurassic (Tr/J) boundary events. The diversity of some benthic fauna decreases through the transitional boundary beds. The coastal marine environment of the lower part of the Baluti Formation is followed by shallower tidal flat and supratidal marginal marine environments at the transitional boundary with the Jurassic‐age Sarki Formation. The alternating calcareous mudrocks and dolomitic limestones of the transitional succession are overlain by a succession of calcareous mudrocks and dolomicrites that form a dolocrete bed in the latest Triassic. The early Jurassic carbonates (lower part of Sarki Formation) were deposited in a shallow‐marine to lagoonal environment. Geochemical evidence supports this interpretation. TOC% increases towards the Tr/J boundary and the lower part of the Sarki Formation. This increase can be interpreted as resulting from the primary precipitation of dolocrete as palaeosol horizons. The variations in the oxygen isotope ratios mainly reflect the facies and diagenetic effects. Th/K ratio is generally constant and shows an increase in the calcareous mudrock beds of the upper part of the Baluti Formation, possibly related to the degradation of K‐bearing clay minerals. Low Th/U ratios are due to the depletion in thorium, typical of many marine carbonates rather than to an increase in authigenic uranium. This explanation is also corroborated by the presence of abundant fossils in some of the studied carbonates. Copyright © 2013 John Wiley & Sons, Ltd.
RETRACTED: MicroRNA‐198 Inhibits Proliferation and Induces Apoptosis of Lung Cancer Cells Via Targeting FGFR1
Authors: Yang Jun , Zhao Heng , Xin Yu , Fan Limin
Published: December 2013

Lung cancer is the most common cause of death from cancer worldwide and recent studies have revealed that microRNAs play critical roles to regulate lung carcinogenesis. Here we present evidence to show the role of miR‐198 in lung cancer development. Our results showed that ectopic expression of miR‐198 inhibits the viability and induces the apoptosis of human non‐small cell lung cancer cells A549 and NCI‐H460, while miR‐198 inhibition resulted in opposite changes. In nude mice miR‐198 inhibits A549 growth of tumor graft. We further demonstrated that miR‐198 directly targets fibroblast growth factor receptor 1 (FGFR1) in lung cancer cells. Restoring FGFR1 expression blocked the inhibitory function of miR‐198, while FGFR1 inhibition achieved the similar phenotypes of miR‐198 overexpression. Hence, our data delineates the molecular pathway by which miR‐198 inhibits lung cancer cellular proliferation and induces apoptosis, and may have important implication for the treatment of lung carcinogenesis. J. Cell. Biochem. 115: 987–995, 2014. © 2013 Wiley Periodicals, Inc.
Sirt1 Activation Ameliorates Renal Fibrosis by Inhibiting the TGF‐β/Smad3 Pathway
Authors: Huang Xin‐Zhong , Wen Donghai , Zhang Min , Xie Qionghong , Ma Leting , Guan Yi , Ren Yueheng , Chen Jing , Hao Chuan‐Ming
Published: December 2013

TGF‐β signaling plays an important role in the pathogenesis and progression of chronic kidney disease (CKD). Smad3, a transcription factor, is a critical fibrogenic mediator of TGF‐β. Sirt1 is a NAD+‐dependent deacetylase that has been reported to modify a number of transcription factors to exert certain beneficial health effects. This study examined the effect of Sirt1 on Smad3 and its role in CKD. Resveratrol attenuated the expression of extracelluar matrix proteins in both the remnant kidney of 5/6th nephrectomized rats and cultured mesangial cells (MMCs) exposed to TGF‐β1. The effect of resveratrol was substantially attenuated in cultured MMCs for which Sirt1 had been knocked down by an shRNA lentivirus. Overexpression of Sirt1 attenuated TGF‐β1‐induced extracelluar matrix expression in cultured cells. Co‐immunoprecipitation studies suggested that Sirt1 could bind with Smad3. Resveratrol treatment enhanced this binding and reduced acetylation levels of Smad3. Resveratrol inhibited the transcription activity of Smad3. Knockdown of Sirt1 increased acetylated Smad3 and substantially enhanced the transcriptional activity following TGF‐β1. Finally, Sirt1 deficiency aggravated renal function damage and markedly enhanced fibrosis in the remnant kidney of 5/6 nephrectomized mice. Taken together, these results identify Sirt1 as an important protective factor for renal fibrosis in a CKD rodent model, and the protective function of Sirt1 is attributable to its action on TGF‐β/Smad3 signaling. Therefore, we suggest that Sirt1 may be a potential therapeutic target for the treatment of CKD. J. Cell. Biochem. 115: 996–1005, 2014. © 2014 Wiley Periodicals, Inc.
Crk at the Quarter Century Mark: Perspectives in Signaling and Cancer
Authors: Kumar Sushil , Fajardo J. Eduardo , Birge Raymond B. , Sriram Ganapathy
Published: December 2013

The Crk adaptor protein, discovered 25 years ago as the transforming gene (v‐crk) product encoded by the CT10 avian retrovirus, has made a great impact on the field of signal transduction. By encoding an oncoprotein that contained a viral gag protein fused to only SH2 and SH3 domains, v‐Crk demonstrated the significance of SH2 and SH3 domains in oncogenic signaling by their virtue of binding in a sequence‐specific context to organize and assemble protein networks. In more recent years, the cellular homologs of Crk (Crk II, Crk I, and CrkL) have been extensively studied, and shown to have critical functions in a wide spectrum of biological and pathological processes that include cell motility, invasion, survival, bacterial pathogenesis, and the efferocytosis of apoptotic cells. Clinically, Crk proteins are implicated in the aggressive behavior of human cancers, including adenocarcinomas of the lung, breast, and stomach, as well as in sarcomas and gliomas. Over‐expression of Crk proteins in human cancers has led to a renewed interest in both their signal transduction pathways and mechanisms of up‐regulation. This prospect summarizes recent developments in Crk biology, including new structural and biochemical roles for the atypical carboxyl‐terminal SH3 (SH3C) domain, revelations regarding the molecular differences between Crk II and Crk L, and the significance of Crk expression in stratified human tumor samples. J. Cell. Biochem. 115: 819–825, 2014. © 2013 Wiley Periodicals, Inc.
Magnetite Nanoparticles Immobilized Pectinase: Preparation, Characterization and Application for the Fruit Juices Clarification
Authors: Mosafa Leila , Shahedi Mohammad , Moghadam Majid
Published: December 2013

In this work, pectinase was immobilized on the surface of silica‐coated magnetite nanoparticles via covalent attachment. The magnetite‐immobilized enzyme was characterized by Fourier transform infrared spectroscopy, X‐ray powder diffraction, scanning electron microscopy and vibrating sample magnetometery techniques. Response Surface Methodology using Minitab Software was applied for statistical designing of operating conditions in order to immobilize pectinase on magnetic nanoparticles. The optimal conditions were obtained at 30 °C and pH 5.5 with 42.97 μl pectinase for 2 h. The immobilization yield was 50.6% at optimized conditions. Compared to the free pectinase, the immobilized pectinase was found to exhibit enhanced enzyme activity, better tolerance to the variation of pH and temperature, and improved storage stability. Both free and immobilized samples reduced the viscosity of apple juice from 1.12 to 0.88 and 0.92 mm2s−1, respectively, after 30 min at their optimum temperature. Furthermore, the immobilized enzyme could be reused six consecutive cycles and the efficiency loss in viscosity reduction was found to be only 8.16%.
An Efficient One‐pot Synthesis of 2‐Amino‐5‐arylidenethiazol‐4‐ones Catalyzed by MgO Nanoparticles
Authors: Shariati Narges , Baharfar Robabeh
Published: December 2013

A mild and efficient protocol for the synthesis of 2‐amino‐5‐arylidene‐1,3‐thiazol‐4(5H)‐ones is reported by three component reaction of aldehydes, rhodanine and secondary amines in the presence of magnesium oxide nanoparticles as heterogeneous nanocatalyst in good yields and short reaction times.
Nuclease‐stimulated homologous recombination at the human β‐globin gene
Authors: Vannocci Tommaso , Kurata Hitoshi , de la Fuente Josu , Roberts Irene A. , Porter Andrew C. G.
Published: December 2013

Background

Mutations in the β‐globin gene (HBB) cause haemoglobinopathies where current treatments have serious limitations. Gene correction by homologous recombination (HR) is an attractive approach to gene therapy for such diseases and is stimulated by gene‐specific endonucleases, including zinc finger nucleases (ZFNs). Customised nucleases targeting HBB have previously been shown to promote HR‐mediated HBB modification in 0.3–60% of drug‐selected cells, although frequencies among unselected cells, more relevant to the goal of correcting HBB in primary stem cells, have not been reported.

Methods

ZFNs targeting HBB were tested for HBB binding (two‐hybrid assay) or HBB cleavage followed by inaccurate end joining (surveyor assay) in bacteria or human cancer cell lines, respectively. ZFN‐stimulated HR was measured in cell lines by a modified fluorescence‐based reporter assay or by targeted insertion of a drug‐resistance marker into endogenous HBB confirmed by Southern analyses.

Results

Although the ZFNs that we assembled in‐house showed limited potential, a commercially commissioned nuclease (ZFN4) enhanced HR‐mediated HBB modification in up to 95% of drug‐selected cells. Among unselected cells, however, this frequency was less than 0.2%. Furthermore, ZFN4 cleaved HBB at an efficiency of 1–2% (surveyor assay) and enhanced the HR reporter assay 20‐fold less efficiently than a control endonuclease.

Conclusions

With ZFN4, we achieved higher efficiencies of HR‐mediated HBB modification than previously reported for drug‐selected cells. Our measurements of ZFN4‐induced HR in unselected cells, however, suggest that improved nucleases must be developed if therapeutic HBB correction is to be achievable in primary stem cells. © 2013 The Authors. Journal of Gene Medicine published by John Wiley & Sons, Ltd.
Best Practices for Building High Performance in Human Resource Management
Authors: Suttapong Ketsaraporn , Srimai Suwit , Pitchayadol Pongsakorn
Published: December 2013

Human resource (HR) professionals have long realized the value of learning from the experiences of other leading organizations—that taking a best practices approach to the HR function can drive the high performance necessary to survive and thrive in a competitive market. An overview of recent studies concerning best practices points to the effectiveness of these approaches in human resource management: providing job security, offering job rotations to stellar performers, providing ongoing training to develop employees' skills, conducting developmental performance appraisals, sharing information and knowledge, providing career opportunities, fostering employee participation, and using performance‐based incentives to reward employees. The application of these and other HR‐oriented best practices that complement an organization's mission, strategy, and culture can help it achieve its objectives while enhancing its reputation. © 2014 Wiley Periodicals, Inc.
Marketing Strategies at the Bottom of the Pyramid: Examples From Nestlé, Danone, and Procter & Gamble
Authors: Payaud Marielle A.
Published: December 2013

The bottom of the pyramid (BoP) refers to markets that serve some of the poorest individuals on the planet. Many multinational corporations contend that they are implementing BoP marketing strategies while selling products targeted to the very poor in developing countries. There are significant differences across marketing strategies directed at BoP consumers, from merely adapting an existing product to the development of an innovative product strategy integrating explicit fair and inclusive growth at the local community level. It is possible to distinguish mere international marketing strategies from genuine BoP strategies, as an analysis of three case studies shows: Nestlé operations in the Central and West African region, and Danone and Procter & Gamble operations in Egypt. Studying the characteristics of the diverse marketing strategies that these firms target to BoP consumers leads to a classification of five types of BoP marketing strategies. The tool presented here will help management understand what a genuine BoP marketing strategy should be and how to improve current marketing practices to include BoP corporate social responsibility principles. © 2014 Wiley Periodicals, Inc.
Optimising image quality in 2D and 3D confocal Raman mapping
Authors: Everall Neil
Published: December 2013

This article compares the quality of Raman images obtained using metallurgical and oil immersion objectives to map complex structures in two and three dimensions. While the performance of these objectives for depth profiling planar structures has been discussed at length in the literature, the same comparison has not yet been made for 3D mapping of complex objects, where additional complications are introduced by non‐planar geometries. Studying samples with increasing complexity shows that the oil immersion objective is strongly preferred because it yields brighter images with better contrast, and eliminates some new and confusing artefacts that do not arise with simple planar objects. Copyright © 2013 John Wiley & Sons, Ltd.
Biodegradable, pH‐Responsive Carboxymethyl Cellulose/Poly(Acrylic Acid) Hydrogels for Oral Insulin Delivery
Authors: Gao Xiaoye , Cao Yue , Song Xiangfu , Zhang Zhe , Zhuang Xiuli , He Chaoliang , Chen Xuesi
Published: December 2013

Biodegradable and pH‐responsive carboxymethyl cellulose/poly(acrylic acid) hybrid hydrogels are synthesized. The hydrogels deswell in acidic artificial gastric fluid (AGF) but rapidly swell in neutral artificial intestinal fluid (AIF), rendering selective enzymatic degradation of the gels as well as accelerated drug release from insulin‐loaded hydrogels in AIF. Oral administration of insulin‐loaded hydrogels to streptozotocin‐induced diabetic rats leads to a continuous decline in the fasting blood glucose level within 6 h post‐administration, and the relative pharmacological availability increases more than 10 times compared to oral administration of free insulin solution. The relative bioavailability of hydrogel‐encapsulated insulin after oral administration to healthy rabbits is 6.6%.
Human whole‐blood 1H2O longitudinal relaxation with normal and high‐relaxivity contrast reagents: Influence of trans‐cell‐membrane water exchange
Authors: Wilson Gregory J. , Woods Mark , Springer Charles S. , Bastawrous Sarah , Bhargava Puneet , Maki Jeffrey H.
Published: December 2013

Purpose

Accurate characterization of contrast reagent (CR) longitudinal relaxivity in whole blood is required to predict arterial signal intensity in contrast‐enhanced MR angiography (CE‐MRA). This study measured the longitudinal relaxation rate constants (R1) over a concentration range for non‐protein‐binding and protein‐binding CRs in ex vivo whole blood and plasma at 1.5 and 3.0 Tesla (T) under physiologic arterial conditions.

Methods

Relaxivities of gadoteridol, gadobutrol, gadobenate, and gadofosveset were measured for [CR] from 0 to 18 mM [mmol(CR)/L(blood)]: the latter being the upper limit of what may be expected in CE‐MRA.

Results

In plasma, the 1H2O R1 [CR]‐dependence was nonlinear for gadobenate and gadofosveset secondary to CR interactions with the serum macromolecule albumin, and was well described by an analytical expression for effective 1:1 binding stoichiometry. In whole blood, the 1H2O R1 [CR]‐dependence was markedly non‐linear for all CRs, and was well‐predicted by an expression for equilibrium exchange of water molecules between plasma and intracellular spaces using a priori parameter values only.

Conclusion

In whole blood, 1H2O R1 exhibits a nonlinear relationship with [CR] over 0 to 18 mM CR. The nonlinearity is well described by exchange of water between erythrocyte and plasma compartments, and is particularly evident for high relaxivity CRs. Magn Reson Med 72:1746–1754, 2014. © 2013 Wiley Periodicals, Inc.
Evolution and functional cross‐talk of protein post‐translational modifications
Authors: Beltrao Pedro , Bork Peer , Krogan Nevan J. , van Noort Vera
Published: December 2013

Protein post‐translational modifications (PTMs) allow the cell to regulate protein activity and play a crucial role in the response to changes in external conditions or internal states. Advances in mass spectrometry now enable proteome wide characterization of PTMs and have revealed a broad functional role for a range of different types of modifications. Here we review advances in the study of the evolution and function of PTMs that were spurred by these technological improvements. We provide an overview of studies focusing on the origin and evolution of regulatory enzymes as well as the evolutionary dynamics of modification sites. Finally, we discuss different mechanisms of altering protein activity via post‐translational regulation and progress made in the large‐scale functional characterization of PTM function.
Frequency correction method for improved spatial correlation of hyperpolarized 13C metabolites and anatomy
Authors: Cunningham Charles H. , Dominguez Viqueira William , Hurd Ralph E. , Chen Albert P.
Published: December 2013

Blip‐reversed echo‐planar imaging (EPI) is investigated as a method for measuring and correcting the spatial shifts that occur due to bulk frequency offsets in 13C metabolic imaging in vivo. By reversing the k‐space trajectory for every other time point, the direction of the spatial shift for a given frequency is reversed. Here, mutual information is used to find the ‘best’ alignment between images and thereby measure the frequency offset. Time‐resolved 3D images of pyruvate/lactate/urea were acquired with 5 s temporal resolution over a 1 min duration in rats (N = 6). For each rat, a second injection was performed with the demodulation frequency purposely mis‐set by +35 Hz, to test the correction for erroneous shifts in the images. Overall, the shift induced by the 35 Hz frequency offset was 5.9 ± 0.6 mm (mean ± standard deviation). This agrees well with the expected 5.7 mm shift based on the 2.02 ms delay between k‐space lines (giving 30.9 Hz per pixel). The 0.6 mm standard deviation in the correction corresponds to a frequency‐detection accuracy of 4 Hz. A method was presented for ensuring the spatial registration between 13C metabolic images and conventional anatomical images when long echo‐planar readouts are used. The frequency correction method was shown to have an accuracy of 4 Hz. Summing the spatially corrected frames gave a signal‐to‐noise ratio (SNR) improvement factor of 2 or greater, compared with the highest single frame. Copyright © 2013 John Wiley & Sons, Ltd.
Safety and efficacy of aprepitant for chemotherapy‐induced nausea and vomiting in pediatric patients: A prospective, observational study
Authors: Bodge Megan , Shillingburg Alexandra , Paul Stephan , Biondo Lisa
Published: December 2013

Pediatric patients between the ages of 12 months and 17 years with a confirmed malignancy who were scheduled to receive aprepitant as part of triple therapy antiemetic prophylaxis for a cycle of moderately‐ or highly emetogenic chemotherapy were eligible for enrollment. Patients were evaluated for the incidence of nausea, episodes of emesis, interference with activities of daily living (ADLs), and appetite through utilization of a patient survey. Eleven patients were enrolled for a total of 20 patient encounters, mean age 9.55 ± 4.85 (range, 12 months–17 years). Aprepitant was well‐tolerated and complete response (CR) rate was 38.9%. Pediatr Blood Cancer 2014;61:1111–1113. © 2013 Wiley Periodicals, Inc.
Investigation of biological factors influencing the placental mRNA profile in maternal plasma
Authors: Tsui Nancy B. Y. , Wong Cesar S. C. , Chow Katherine C. K. , Lo Elena S. F. , Cheng Yvonne K. Y.
Published: December 2013

Objective

Circulating placental‐derived RNA is useful for noninvasive prenatal investigation. However, in addition to placental gene expression, there are limited investigations on other biological parameters that may affect the circulating placental RNA profile. In this study, we explored two of these potential parameters.

Methods

We first demonstrated the existence of such biological parameters by comparing the relative levels of a panel of placental‐derived transcripts between the placentas and maternal plasma by digital PCRs. We then compared the post‐delivery clearance of the transcripts by serial plasma samples collected from pregnant women after delivery. We also studied the placental in vivo localization of the transcripts by in situ hybridization.

Results

There was an imperfect correlation of the transcript levels between the placentas and maternal plasma, with placenta‐specific 4 (PLAC4) mRNA showing the largest discrepancy. Although PLAC4 mRNA showed a similar clearance half‐life with other transcripts, we observed a preferential localization of PLAC4 mRNA around the villous surface. We speculated that this phenomenon might play a role in favoring the release of PLAC4 mRNA molecules into maternal plasma.

Conclusion

We revealed that in addition to expression levels in the placenta, other biological factors might interplay to determine the maternal plasma profile of placental‐derived RNAs. © 2013 John Wiley & Sons, Ltd.
Light Harvesting and Photoemission by Nanoparticles for Photodynamic Therapy
Authors: Arguinzoniz Amaia Garaikoetxea , Ruggiero Emmanuel , Habtemariam Abraha , Hernández‐Gil Javier , Salassa Luca , Mareque‐Rivas Juan C.
Published: December 2013

This review provides an overview of recent efforts to utilize light harvesting and photoemission by nanoparticles (NPs) for photodynamic therapy (PDT) applications. In particular, it focuses on the recent use of quantum dots (QDs) and upconverting nanophosphors (UCNPs), which over the past decade have captivated considerable interest in biomedical research as new classes of fluorescent probes for in vivo biomolecular and cellular imaging. Increasingly, the unique properties of QDs and UCNPs are becoming the focus of attention in PDT as an emerging cancer treatment modality where a photosensitizer molecule (PS) exposed to light of a wavelength matching its absorption spectrum mediates cytotoxic effects. An overview of the processes and approaches that have been used to induce and optimize photoinduced energy and charge transfer processes and generation of different cytotoxic species ranging from reactive oxygen species to inorganic metal‐based drugs using these NPs, as well as for their targeted delivery in a cell‐ or tissue‐specific manner is presented. The main challenge for nanomaterials entering mainstream clinical practice is understanding and overcoming their toxicity. Hence, some of the known mechanisms by which QDs and UCNPs can cause unwanted toxicity are briefly reviewed, as well as how they can be minimized.
Intersubunit communication in the dihydroorotase–aspartate transcarbamoylase complex of Aquifex aeolicus
Authors: Evans Hedeel Guy , Fernando Roshini , Vaishnav Asmita , Kotichukkala Mahalakshmi , Heyl Deborah , Martin Philip D. , Hachem Fatme , Brunzelle Joseph S. , Edwards Brian F.P. , Evans David R.
Published: December 2013

Aspartate transcarbamoylase and dihydroorotase, enzymes that catalyze the second and third step in de novo pyrimidine biosynthesis, are associated in dodecameric complexes in Aquifex aeolicus and many other organisms. The architecture of the dodecamer is ideally suited to channel the intermediate, carbamoyl aspartate from its site of synthesis on the ATC subunit to the active site of DHO, which catalyzes the next step in the pathway, because both reactions occur within a large, internal solvent‐filled cavity. Channeling usually requires that the reactions of the enzymes are coordinated so that the rate of synthesis of the intermediate matches its rate of utilization. The linkage between the ATC and DHO subunits was demonstrated by showing that the binding of the bisubstrate analog, N‐phosphonacetyl‐L‐aspartate to the ATC subunit inhibits the activity of the distal DHO subunit. Structural studies identified a DHO loop, loop A, interdigitating between the ATC domains that would be expected to interfere with domain closure essential for ATC catalysis. Mutation of the DHO residues in loop A that penetrate deeply between the two ATC domains inhibits the ATC activity by interfering with the normal reciprocal linkage between the two enzymes. Moreover, a synthetic peptide that mimics that part of the DHO loop that binds between the two ATC domains was found to be an allosteric or noncompletive ATC inhibitor (Ki = 22 μM). A model is proposed suggesting that loop A is an important component of the functional linkage between the enzymes.
A novel transport assimilation method for the Atlantic meridional overturning circulation at 26°N
Authors: Hermanson Leon , Dunstone Nick , Haines Keith , Robson Jon , Smith Doug , Sutton Rowan
Published: December 2013

One of the prerequisites for achieving skill in decadal climate prediction is to initialize and predict the circulation in the Atlantic Ocean successfully. The RAPID array measures the Atlantic Meridional Overturning Circulation (MOC) at 26°N. Here we develop a method to include these observations in the Met Office Decadal Prediction System (DePreSys). The proposed method uses covariances of overturning transport anomalies at 26°N with ocean temperature and salinity anomalies throughout the ocean to create the density structure necessary to reproduce the observed transport anomaly. Assimilating transport alone in this way effectively reproduces the observed transport anomalies at 26°N and is better than using basin‐wide temperature and salinity observations alone. However, when the transport observations are combined with in situ temperature and salinity observations in the analysis, the transport is not currently reproduced so well. The reasons for this are investigated using pseudo‐observations in a twin experiment framework. Sensitivity experiments show that the MOC on monthly time‐scales, at least in the HadCM3 model, is modulated by a mechanism where non‐local density anomalies appear to be more important for transport variability at 26°N than local density gradients.
Training to maintain surgical skills during periods of robotic surgery inactivity
Authors: Guseila Loredana M. , Saranathan Archana , Jenison Eric L. , Gil Karen M. , Elias John J.
Published: December 2013

Background

The study was performed to establish a level of practice needed for newly‐trained residents to maintain robotic surgical skills during periods of robotic inactivity.

Methods

Ten surgical residents were trained to a standardized level of robotic surgery proficiency with inanimate models. At the end of two, four and six weeks, the residents practiced with the models for a total of one hour. Each resident performed a timed tissue closure task immediately after reaching the proficiency standards and twice in succession at eight weeks. Time to completion was compared between the three trials with a repeated measures ANOVA and a post‐hoc test.

Results

Average time to complete the tissue closure task decreased by more than 25% over the period between reaching the proficiency standards and the trials at eight weeks, with the difference significant (P < 0.004).

Conclusions

Biweekly practice for one hour was sufficient to maintain robotic surgical skills. Copyright © 2013 John Wiley & Sons, Ltd.
Putting the Cart Before the Horse: The Creation of Essences out of Processes in Science Education Research
Authors: LUNDEGÅRD IANN , HAMZA KARIM M.
Published: December 2013

This article addresses the problem of treating generalizations of human activity as entities and structures that ultimately explain the activities from which they were initially drawn. This is problematic because it involves a circular reasoning leading to unwarranted claims explaining the originally studied activities of science teaching and learning. Unlike other fields within social science research, this problem has not been appreciated and discussed in the science education literature and the field thus needs to be reminded of it. A heuristic specifically developed for the purposes of this article is applied to two examples taken from a much‐cited research in the field. Through the examples it is argued that the practice of creating entities out of generalizations of science classroom activities leads to a number of unintended consequences. It is further argued that the stated purposes in the two example articles would actually have been better served by investigating the entire processes through which the activities develop, as well as how the activities may change through teaching. The article concludes that through the search for explanations caused by underlying entities, science education research runs a risk of alienating its results from the activities from which it initially wanted to meliorate.
Designing and Implementing Multicultural Initiatives: Guiding Principles
Authors: Watt Sherry K.
Published: December 2013

This chapter provides guiding principles for designing and implementing successful multicultural initiatives. A rationale for why these elements transcend both higher education and student affairs settings is presented. In addition to providing guiding principles, this chapter includes advice for socially and politically conscious‐minded professionals who are leading the implementation of multicultural initiatives on their campus.
Addressing Underrepresentation in STEM Fields through Undergraduate Interventions
Authors: Linley Jodi L. , George‐Jackson Casey E.
Published: December 2013

This chapter provides an overview of undergraduate STEM initiatives for underrepresented minorities and women, as well as a description and critical analysis of one comprehensive federally funded initiative at a research‐intensive university.
Concise Review: The Plasticity of Stem Cell Niches: A General Property Behind Tissue Homeostasis and Repair
Authors: Rojas-Ríos Patricia , González-Reyes Acaimo
Published: December 2013

Stem cell activity is tightly regulated during development and in adult tissues through the combined action of local and systemic effectors. While stem cells and their microenvironments are capable of sustaining homeostasis in normal physiological circumstances, they also provide host tissues with a remarkable plasticity to respond to perturbations. Here, we review recent discoveries that shed light on the adaptive response of niches to systemic signals and aging, and on the ability of niches to modulate signaling upon local perturbations. These characteristics of stem cells and their niches give organs an essential advantage to deal with aging, injury or pathological conditions. Stem Cells  2014;32:852–859
Designing SoTL Studies—Part I: Validity
Authors: Bartsch Robert A.
Published: December 2013

This chapter discusses how to improve validity in SoTL studies through generating appropriate measures and using designs that examine causality between an activity and students' performance.
Outcome of fetuses with short femur length detected at second‐trimester anomaly scan: a national survey
Authors: Mathiesen J. M. , Aksglaede L. , Skibsted L. , Petersen O. B. , Tabor A. ,   the Danish Fetal Medicine Study Group
Published: December 2013

Objective

To assess the relationship between the finding of fetal femur diaphysis length (FL) below the 5th percentile at the second‐trimester scan and pregnancy outcome, in a population in which more than 90% of women attend first‐trimester screening.

Methods

This was a retrospective study of all Danish singleton pregnancies with a 17–22‐week anomaly scan between 1 January 2008 and 30 June 2011. Information on FL and gestational age (GA) at anomaly scan, on birth weight and GA at delivery and on chromosomal abnormalities was obtained from the Danish Fetal Medicine Database.

Results

Short FL was identified in 2718 (1.8%) of 147 766 fetuses and was present in 11 (16.2%) of the 68 fetuses affected by trisomy 21 (positive likelihood ratio (LR+) 8.8 (95% CI, 5.1–15.2)). Trisomy 13/18 and unbalanced autosomal structural abnormalities were also associated with a short FL in three (12.0%, LR+ 6.5 (95% CI, 2.3–18.9)) and eight (32.0%, LR+ 17.4 (95% CI, 9.8–30.9)) of the cases, respectively. The risk of a fetus having trisomy 21, trisomy 18, trisomy 13 or an unbalanced autosomal structural abnormality was 1 : 123 (95% CI, 79–192), given a short FL. Pregnancies with a fetus with short FL were more often affected by early preterm delivery (before 34 weeks) (5.6%; odds ratio (OR) = 4.2 (95% CI, 3.5–4.9)) and small‐for‐gestational‐age (SGA) infants (13.9%; OR = 4.3 (95% CI, 3.8–4.8)).

Conclusion

Short FL at the second‐trimester anomaly scan is associated with a significantly higher relative risk of chromosomal abnormalities, and a substantially higher absolute risk for SGA and early preterm delivery. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd
Replication enabled distributed cache invalidation method: replication enabled distributed cache management system for wireless mobile networks
Authors: Fawaz Kassem , Artail Abdalla , Al‐Khansa Rasha , Artail Hassan , Safa Haidar
Published: December 2013

This work proposes a replication scheme that is implemented on top of a previously proposed system for MANETs that cache submitted queries in special nodes, called query directories, and uses them to locate the data (responses) that are stored in the nodes that first request them, called caching nodes. The system, which was named distributed cache invalidation method (DCIM), includes client‐based mechanisms for keeping the cached data consistent with the data source. In this work, we extend DCIM to handle cache replicas inside the MANET. For this purpose, we utilize a push‐based approach within the MANET to propagate the server updates to replicas inside the network. The result is a hybrid approach that utilizes the benefits of pull approaches for client server communication and those of push approaches inside the network between the replicas. The approach is analyzed analytically, and the appropriate number of replicas is obtained, where it was concluded that full replication of the indices of data items at the query directory and two‐partial replication of the data items themselves makes most sense. Simulation results based on ns2 demonstrate the ability of the added replication scheme to lower delays and improve hit ration at the cost of mild increases in overhead traffic. Copyright © 2013 John Wiley & Sons, Ltd.
Regional Economic Resilience: European Experiences and Policy Issues
Authors: Wink Rüdiger
Published: December 2013

This introductory paper looks at recent debates on the concept of regional economic resilience and focuses on three elements of debate: (1) indicator systems and consideration of the normative content of the concept; (2) the evolutionary dimension of the concept and its inter-disciplinary linkages; (3) the policy dimension and challenges for the development of policy recommendations. The author discusses the state of the debate and presents some directions for future research priorities.
Vulnerable Atherosclerotic Carotid Plaque Evaluation by Ultrasound, Computed Tomography Angiography, and Magnetic Resonance Imaging: An Overview
Authors: Naim Cyrille , Douziech Maxime , Therasse Éric , Robillard Pierre , Giroux Marie-France , Arsenault Frederic , Cloutier Guy , Soulez Gilles
Published: December 2013

Ischemic syndromes associated with carotid atherosclerotic disease are often related to plaque rupture. The benefit of endarterectomy for high-grade carotid stenosis in symptomatic patients has been established. However, in asymptomatic patients, the benefit of endarterectomy remains equivocal. Current research seeks to risk stratify asymptomatic patients by characterizing vulnerable, rupture-prone atherosclerotic plaques. Plaque composition, biology, and biomechanics are studied by noninvasive imaging techniques such as magnetic resonance imaging, computed tomography, ultrasound, and ultrasound elastography. These techniques are at a developmental stage and have yet to be used in clinical practice. This review will describe noninvasive techniques in ultrasound, magnetic resonance imaging, and computed tomography imaging modalities used to characterize atherosclerotic plaque, and will discuss their potential clinical applications, benefits, and drawbacks.
Democratic Pieces: Autocratic Elections and Democratic Development since 1815
Authors: Miller Michael K.
Published: December 2013

This article overviews the history of autocratic elections since 1815 and then tests how a country's experience with autocratic elections influences both democratization and democratic survival. To comprehensively capture this history, the study employs original measures of Robert Dahl's electoral dimensions of contestation and participation. First, it shows that autocratic elections have been common for centuries, but that their character has changed dramatically over time. Whereas high contestation almost always preceded high participation prior to 1940, the opposite occurs in modern regimes. Secondly, it demonstrates that a country's history of contestation predicts both democratization and democratic survival, whereas participation is positive for survival but generally negative for democratization. Thus, democracies are more likely to survive if they experience autocratic elections prior to democratizing, which has implications for democracy promotion and future political development.
Towards Motivic Quantum Cohomology of M̄0,S
Authors: Manin Yuri I. , Smirnov Maxim
Published: December 2013

We explicitly calculate some Gromov–Witten correspondences determined by maps of labelled curves of genus 0 to the moduli spaces of labelled curves of genus 0. We consider these calculations as the first step towards studying the self-referential nature of motivic quantum cohomology.
Cayley Forms and Self-Dual Varieties
Authors: Catanese F.
Published: December 2013

Generalized Chow forms were introduced by Cayley for the case of 3-space; their zero set on the Grassmannian G(1, 3) is either the set Z of lines touching a given space curve (the case of an ‘honest’ Cayley form), or the set of lines tangent to a surface. Cayley gave some equations for F to be a generalized Cayley form, which should hold modulo the ideal generated by F and by the quadratic equation Q for G(1, 3). Our main result is that F is a Cayley form if and only if Z = G(1, 3) ∩ {F = 0} is equal to its dual variety. We also show that the variety of generalized Cayley forms is defined by quadratic equations, since there is a unique representative F0 + QF1 of F, with F0, F1 harmonic, such that the harmonic projection of the Cayley equation is identically 0. We also give new equations for honest Cayley forms, but show, with some calculations, that the variety of honest Cayley forms does not seem to be defined by quadratic and cubic equations.
Elliptic Fibrations on K3 Surfaces
Authors: Nikulin Viacheslav V.
Published: December 2013

This paper consists mainly of a review and applications of our old results relating to the title. We discuss how many elliptic fibrations and elliptic fibrations with infinite automorphism groups (or Mordell–Weil groups) an algebraic K3 surface over an algebraically closed field can have. As examples of applications of the same ideas, we also consider K3 surfaces with exotic structures: with a finite number of non-singular rational curves, with a finite number of Enriques involutions, and with naturally arithmetic automorphism groups.
Leuconostoc citreumMB1 as biocontrol agent ofListeria monocytogenesin milk
Authors: Pujato Silvina A , del L Quiberoni Andrea , Candioti Mario C , Reinheimer Jorge A , Guglielmotti Daniela M
Published: December 2013

Cell-free supernatant fromLeuconostoc citreumMB1 revealed specific antilisterial activity. Preliminary studies demonstrated the proteinaceous, heat-stable, bacteriocin-like trait of the antimicrobial components present in the supernatant. Determination of the genes encoding bacteriocins by PCR and DNA sequencing led to amplification products highly homologous with leucocin A (found in diverseLeuconostocspecies) and UviB (found inLeuc. citreumKM20) sequences. Additionally, antimicrobial activity of cell-free supernatant fromLeuc. citreumMB1 was revealed by an inhibition halo of the SDS-PAGE gel subjected to a direct detection usingListeria monocytogenesas indicator strain. Different assays were carried out to assess the capacity ofLeuc.citreumMB1 to controlList. monocytogenesgrowth: (i) inactivation kinetics of the pathogen by antilisterial compounds present in concentrated cell-free supernatant fromLeuc. citreumMB1, (ii) evaluation of optimalLeuc. citreumMB1 initial concentration to obtain maximumList. monocytogenesATCC 15313 inhibition, and (iii) biocontrol ofList. monocytogenesATCC 15313 withLeuc. citreumMB1 during growth in milk at refrigeration temperature. According to our results, it is unquestionable that at least one bacteriocin is active inLeuc. citreumMB1, since important antilisterial activity was verified either in its cell-free supernatant or in co-culture experiments. Co-culture tests showed that ∼107 CFU/mlLeuc. citreumMB1 was the optimal initial concentration to obtain maximum pathogen inhibition. Moreover,Leuc. citreumMB1 was able to delayList. monocytogenesgrowth at refrigerated temperature.
Ultrasound effects on the assembly of casein micelles in reconstituted skim milk
Authors: Liu Zheng , Juliano Pablo , Williams Roderick PW , Niere Julie , Augustin Mary Ann
Published: December 2013

Reconstituted skim milks (10 % w/w total solids, pH 6·7–8·0) were ultrasonicated (20, 400 or 1600 kHz at a specific energy input of 286 kJ/kg) at a bulk milk temperature of <30 °C. Application of ultrasound to milk at different pH altered the assembly of the casein micelle in milk, with greater effects at higher pH and lower frequency. Low frequency ultrasound caused greater disruption of casein micelles causing release of protein from the micellar to the serum phase than high frequency. The released protein re-associated to form aggregates of smaller size but with surface charge similar to the casein micelles in the original milk. Ultrasound may be used as a physical intervention to alter the size of the micelles and the partitioning of caseins between the micellar and serum phases in milk. The altered protein equilibria induced by ultrasound treatment may have potential for the development of milk with novel functionality.
Optimisation of medium composition for probiotic biomass production using response surface methodology
Authors: Anvari Masumeh , Khayati Gholam , Rostami Shora
Published: December 2013

This study was aimed to optimise lactose, inulin and yeast extract concentration and also culture pH for maximising the growth of a probiotic bacterium,Bifidobacterium animalissubsp.lactisin apple juice and to assess the effects of these factors by using response surface methodology. A second-order central composite design was applied to evaluate the effects of these independent variables on growth of the microorganism. A polynomial regression model with cubic and quadratic terms was used for analysis of the experimental data. It was found that the effects involving inulin, yeast extract and pH on growth of the bacterium were significant, and the strongest effect was given by the yeast extract concentration. Estimated optimum conditions of the factors on the bacterial growth are as follows: lactose concentration=9·5 g/l; inulin concentration=38·5 mg/l; yeast extract concentration=9·6 g/l and initial pH=6·2.