bluuebunny/crossref_metadata_2025 huggingface dataset:
Covalent functionalization of carbon fiber with poly(acrylamide) by reversible addition–fragmentation chain transfer polymerization for improving carbon fiber/epoxy interface
Authors: Xiong Lei , Qin Xiaokang , Liang Hongbo , Huang Shengmei , Lian Zeyang
Published: May 2015

A novel method was developed for grafting poly(acrylamide) (PAAM) on to the carbon fiber (CF) surface via reversible addition–fragmentation chain transfer (RAFT) polymerization to improve the interaction between carbon fibers and epoxy matrix in the composites system. The carbon fibers were first treated with nitric acid and γ‐methacryloxypropyltrimethoxy silane (KH570). Then, the PAAM was grafting onto the carbon fiber surface via RAFT polymerization. The resulted carbon fibers functionalized with PAAM (CF‐PAAM) were characterized by FTIR, XPS, and TGA, and the results revealed that CF‐PAAM were synthesized successfully. The introduction of PAAM chains could make the fiber surface rougher and introduce a large numbers of –NH2 groups, which can improve the interfacial adhesion in the composites. The microbond test results showed that the interfacial shear strength (IFSS) of the composites reinforced by CF‐PAAM has been enhanced about 107%. POLYM. COMPOS., 38:27–31, 2017. © 2015 Society of Plastics Engineers
Effect of agave fiber surface treatment on the properties of polyethylene composites produced by dry‐blending and compression molding
Authors: Cisneros‐López E.O. , Anzaldo J. , Fuentes‐Talavera F.J. , González‐Núñez R. , Robledo‐Ortíz J.R. , Rodrigue D.
Published: May 2015

In this work, the effect of natural fiber surface treatment with maleated polyethylene (MAPE) is presented to improve the mechanical properties of natural fiber composites (NFC). In particular, a simple dry blending technique was used to disperse natural fibers (agave) in a polymer matrix (linear low density polyethylene) and produce samples via compression molding. The effect of fiber content was also studied (0, 10, 20, 30, and 40 wt%) and the samples were characterized in terms of morphology, density, hardness, as well as mechanical (tensile, flexion, and impact) and thermal (DSC and TGA) properties. The results show that the simple dry‐blending method is efficient to produce homogeneous NFC and that surface treatment can substantially improve composite modulus (164%) and strength (121%). POLYM. COMPOS., 38:96–104, 2017. © 2015 Society of Plastics Engineers
Iron and FER‐LIKE IRON DEFICIENCY‐INDUCED TRANSCRIPTION FACTOR‐dependent regulation of proteins and genes in Arabidopsis thaliana roots
Authors: Mai Hans‐Jörg , Lindermayr Christian , von Toerne Christine , Fink‐Straube Claudia , Durner Jörg , Bauer Petra
Published: May 2015

Iron is an essential micronutrient for plants, and iron deficiency requires a variety of physiological adaptations. FIT (FER‐LIKE IRON DEFICIENCY‐INDUCED TRANSCRIPTION FACTOR) is essential for the regulation of iron uptake in Arabidopsis thaliana roots. FIT is transcriptionally as well as posttranscriptionally regulated in response to iron supply. To investigate to which extent posttranscriptional regulation upon iron deficiency applies to proteins and to determine the dependency on FIT, we performed a parallel proteomic and transcriptomic study with wild‐type, a fit knock‐out mutant, and a FIT overexpressing Arabidopsis line. Among 92 proteins differentially regulated by iron and/or FIT, we identified 30 proteins, which displayed differential regulation at the transcriptional level. Eleven protein spots were regulated in at least one of the data points even contrary to the respective genes dependent on FIT. We found ten proteins in at least two forms. The analysis of functional classification showed enriched GO terms among the posttranscriptionally regulated genes and of proteins, that were downregulated or absent in the fit knock‐out mutant. Taken together, we provide evidence for iron and FIT‐dependent posttranscriptional regulation in iron homeostasis in A. thaliana.
The relationships of catalytic activity of metal Schiff base catalysts and the Hammett constants of their anion–cationic substituents on ligand
Authors: Chen Hang , Jia Lu , Yao Jia , Hu Jinghui , Chen Kexian , Chen Zhirong , Li Haoran
Published: May 2015

For quaternary ammonium, pyridinium, or imidazolium anion–cationic substituents, a linear relationship can be established between the reactivity of metal Schiff base catalysts and the Hammett constants of their anion–cationic substituents with multi‐atomic anions on ligand based on the theoretical and experimental works. Copyright © 2015 John Wiley & Sons, Ltd.
Fabrication and characterization of UV‐crosslinkable thermoresponsive composite fibers with magnetic properties
Authors: Huang Shih‐Ru , Lin King‐Fu , Don Trong‐Ming , Chiu Wen‐Yen , Lin Mei‐Fei
Published: May 2015

Crosslinking magnetic thermoresponsive composite (MTC) fiber mats were fabricated by electrospinning process and followed by UV curing. Thermoresponsive poly‐(N‐isopropylacrylamide) (PNIPAAm) and magnetic Fe3O4 were firstly synthesized by redox‐initiated polymerization and co‐precipitation, respectively. A crosslinking agent (dipentaerythritol hexylacrylate) and photoinitiator for providing crosslinking ability were then mixed with PNIPAAm and Fe3O4 in ethanol as the electrospinning solution. After electrospinning and subsequent UV irradiation, the MTC fiber mats were thus obtained. Thermoresponsivity of the MTC fibers was measured by both DSC and swelling test. MTC fiber mat exhibited better water‐absorption capability and thermoresponsivity than corresponding film. Morphological analysis was observed by SEM and TEM, and the magnetic property was measured by SQUID. The thermoresponsive magnetic behavior of MTC fiber mat in water was observed under various temperatures and magnetic fields. Vitamin B12 used as a model drug was loaded in the MTC fiber mats and the drug‐release behavior was then studied. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2152–2162
The mechanism and a slip model for the initial plastic deformation of amorphous polyethylene under uniaxial tension
Authors: Zeng Fanlin , Hu Enlai , Sun Yi , Qu Jianmin
Published: May 2015

The mechanical behaviors of a polyethylene (PE) bulk consisting of amorphous molecular chains under uniaxial tension have been explored using molecular simulations. The stress–strain relationship and the plastic deformations of the PE bulk have been analyzed. Two deformation stages were found in the stress–strain curve, the elastic stage with a straight linear part of the curve and the plastic stage with a flat sawtooth‐like part. The Young's modulus calculated from the elastic part is in good agreement with experimental results. Some key parameters such as the energy variations in different terms reveal that the interchain slip should be chiefly responsible for the initial plastic deformations of amorphous PE under uniaxial tension. In order to address how this slip influences the plastic deformations, the mechanical details of a single chain have been elucidated when it was pulled out from two PE clusters consisting of regular and amorphous chains, respectively. The interchain slip, found as the basic movement style, is responsible for the movement of the stretched chain. Both the critical slip force and the critical slip length have been found in these two cases. For the straight chain pulled out from the cluster with regular chains, the critical slip force is about 1.81 nN and the critical slip length is about 40 polymerization degrees. While for the chain in the amorphous cluster, the critical force is about 0.86 nN and the critical length is almost the same. Based on the simulation results, a meso slip model has been deduced to explain the behaviors of the amorphous PE bulk under uniaxial tension. With reference to the slip model of single crystals and polycrystals a constitutive relation was obtained by considering the Young's modulus, the equivalent slip stress and the average orientation parameters of each chain. The comparison of the results from the constitutive relation and the simulations proves that this model does well in predicting the mechanical behaviors of amorphous PE under uniaxial tension in general. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 986–998
Luminescent property and mechanism of ZnAl2O4 ultraviolet emitting phosphor
Authors: Ishinaga Takeaki , Iguchi Taku , Kominami Hiroko , Hara Kazuhiko , Kitaura Mamoru , Ohnishi Akimasa
Published: May 2015

ZnAl2O4 ultraviolet (UV) emitting phosphor has been studied for next‐generation ultraviolet emission device. In this work, to investigate the mechanism of ZnAl2O4, the phosphor was evaluated and analyzed using various methods. It is thought that the optimum ratio of source materials to obtain the single phase of ZnAl2O4 is 0.975. UV emission peak of ZnAl2O4 was changed from around 250 nm to 270 nm and the absorption edge was shifted to lower energy as increase the ratio of source materials. It is thought that bandgap of ZnAl2O4 became narrower as increase the ratio of source materials. From the results of annealing in active carbon, it became clear that the UV emission from ZnAl2O4 was caused oxygen vacancy. Additionally, from the results of sterilization examination, it is thought that the properties of ZnAl2O4 are promising for using it as candidate for sterilization. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐scale analysis of atomic layer deposition processes: Predicting the transition from mass‐transfer to kinetically limited regimes
Authors: Adomaitis Raymond A.
Published: May 2015

The relative rates of adsorption and irreversible reaction are modeled for a prototypical atomic layer deposition (ALD) system. Surface species balance modeling equations are processed through a reaction factorization procedure to eliminate redundant dynamic modes. The resulting singular perturbation problem then is used to develop a criterion that distinguishes between mass‐transfer and kinetically‐limited deposition regimes for this dynamic process. Detailed simulations of a TMA/water alumina ALD process are used to evaluate our analysis approach and to demonstrate the dominance of mass‐transfer limitations for this system during both precursor exposure periods. Our analysis shows the increasing likelihood of encountering mass‐transfer limitations at reduced temperatures, a finding opposite of what might be expected. We find that the ALD dynamics evolve on a manifold defined by the balancing of adsorption and irreversible reaction rates, further reducing the dynamic dimension of the deposition dynamics. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of tin oxides SnO2–x in the entire composition range (x = 0 to 1) by ion‐beam sputter‐deposition
Authors: Becker Martin , Polity Angelika , Klar Peter J. , Meyer† Bruno K.
Published: May 2015

Ion‐beam sputter‐deposition (IBSD) was used to reactively deposit tin oxide crystalline films at oxygen fluxes of 3–15 sccm and at substrate temperatures of 100–600 °C. Analysing the samples by X‐ray diffraction and Raman spectro‐ scopy yields a map of the crystalline structures in dependence on the growth parameters. In addition to SnO2, pure SnO films of high quality and an intermediate phase such as Sn2O3 or Sn3O4 can be reproducibly obtained. Thus, IBSD is, to our knowledge, the only thin‐film deposition technique verified yet to reliably produce samples in the entire composition range of tin oxides. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)
A Pipeline for Trunk Detection in Trellis Structured Apple Orchards
Authors: Bargoti Suchet , Underwood James P. , Nieto Juan I. , Sukkarieh Salah
Published: May 2015

The ability of robots to meticulously cover large areas while gathering sensor data has widespread applications in precision agriculture. For autonomous operations in orchards, a suitable information management system is required, within which we can gather and process data relating to the state and performance of the crop over time, such as distinct yield count, canopy volume, and crop health. An efficient way to structure an information system is to discretize it to the individual tree, for which tree segmentation/detection is a key component. This paper presents a tree trunk detection pipeline for identifying individual trees in a trellis structured apple orchard, using ground‐based lidar and image data. A coarse observation of trunk candidates is initially made using a Hough transformation on point cloud lidar data. These candidates are projected into the camera images, where pixelwise classification is used to update their likelihood of being a tree trunk. Detection is achieved by using a hidden semi‐Markov model to leverage from contextual information provided by the repetitive structure of an orchard. By repeating this over individual orchard rows, we are able to build a tree map over the farm, which can be either GPS localized or represented topologically by the row and tree number. The pipeline was evaluated at a commercial apple orchard near Melbourne, Australia. Data were collected at different times of year, covering an area of 1.6 ha containing different apple varieties planted on two types of trellis systems: a vertical I‐trellis structure and a Güttingen V‐trellis structure. The results show good trunk detection performance for both apple varieties and trellis structures during the preharvest season (87– accuracy) and near perfect trunk detection performance (99% accuracy) during the flowering season.
Start‐up designs for response‐adaptive randomization procedures with sequential estimation
Authors: Haines Linda M. , Sadiq Hassan
Published: May 2015

Response‐adaptive randomization procedures are appropriate for clinical trials in which two or more treatments are to be compared, patients arrive sequentially and the response of each patient is recorded before the next patient arrives. However, for those procedures that involve sequential estimation of model parameters, start‐up designs are commonly required in order to provide initial estimates of the parameters. In this paper, a suite of such start‐up designs for two treatments and binary patient responses are considered and compared in terms of the numbers of patients required in order to give meaningful parameters estimates, the number of patients allocated to the better treatment, and the bias in the parameter estimates. It is shown that permuted block designs with blocks of size 4 are to be preferred over a wide range of parameter values. For the case of two treatments, normal responses and selected start‐up procedures, a design incorporating complete randomization followed appropriately by repeats of one of the treatments yields the minimum expected number of patients and is to be preferred. Copyright © 2015 John Wiley & Sons, Ltd.
Efficient online cycle detection technique combining with Steensgaard points‐to information
Authors: Liu Fei , Li Bixin , Nasre Rupesh
Published: May 2015

Pointer analysis is a key static analysis during compilation. Several client analyses and transformations rely on precise pointer information to optimize programs. Therefore, it is paramount to improve the efficiency of pointer analysis. A critical piece of an inclusion‐based pointer analysis is online cycle detection. The efficiency of pointer analysis is significantly influenced by the efficacy of detecting cycles. Existing approaches perform poorly when they guess cycle formation in the constraint graph. Thus, the number of false cycle‐detection triggers of the state‐of‐the‐art methods is considerably high (over 99% on Standard Performance Evaluation Corporation (SPEC) benchmarks). In this paper, we propose bootstrapping as a way to improve cycle detection predictability of pointer analysis. The main idea is to run a sequence of increasingly precise analyses to feed into the next more precise analysis to improve the efficiency of the latter analysis. In this process, we develop a new notion of pointer equivalence called constraint equivalence. Using Steensgaard's fast unification algorithm as the bootstrap, we devise a new cycle detection method for Andersen's inclusion‐based analysis. We measure the effectiveness of our approach using a suite of programs including SPEC 2000 benchmarks and two open‐source programs, and find that our method can reduce the number of false cycle detections by almost 22× compared with a state‐of‐the‐art method. This leads to an overall analysis time improvement of 18% on an average. Copyright © 2015 John Wiley & Sons, Ltd.
VoIP traffic in wireless mesh networks: a MOS‐based routing scheme
Authors: Serrano Salvatore , Campobello Giuseppe , Leonardi Alessandro , Palazzo Sergio , Galluccio Laura
Published: May 2015

Support of Voice over Internet Protocol (VoIP) services in wireless mesh networks requires implementation of efficient policies to support low‐delay data delivery. Multipath routing is typically supported in wireless mesh networks at the network level to provide high fault tolerance and load balancing because links in the proximity of the wireless mesh gateways can be very stressed and overloaded, thus causing scarce performance. As a consequence of using multipath solutions, lower delay and higher throughput can be supported also when a given path is broken because of mobility or bad channel conditions, and alternative routes are available. This can be a relevant improvement especially when assuming that real‐time traffic, such as VoIP, travels into the network. In this paper, we address the problem of Quality of Service (QoS) support in wireless mesh networks and propose a multipath routing strategy that exploits the Mean Opinion Score (MOS) metric to select the most suitable paths for supporting VoIP applications and performing adaptive load balancing among the available paths to equalize network traffic. Performance results assess the effectiveness of the proposed approach when compared with other existing methodologies. Copyright © 2015 John Wiley & Sons, Ltd.
Basic mathematical cognition
Authors: Gaber David , Schlimm Dirk
Published: May 2015

Mathematics is a powerful tool for describing and developing our knowledge of the physical world. It informs our understanding of subjects as diverse as music, games, science, economics, communications protocols, and visual arts. Mathematical thinking has its roots in the adaptive behavior of living creatures: animals must employ judgments about quantities and magnitudes in the assessment of both threats (how many foes) and opportunities (how much food) in order to make effective decisions, and use geometric information in the environment for recognizing landmarks and navigating environments. Correspondingly, cognitive systems that are dedicated to the processing of distinctly mathematical information have developed. In particular, there is evidence that certain core systems for understanding different aspects of arithmetic as well as geometry are employed by humans and many other animals. They become active early in life and, particularly in the case of humans, develop through maturation. Although these core systems individually appear to be quite limited in application, in combination they allow for the recognition of mathematical properties and the formation of appropriate inferences based upon those properties. In this overview, the core systems, their roles, their limitations, and their interaction with external representations are discussed, as well as possibilities for how they can be employed together to allow us to reason about more complex mathematical domains. WIREs Cogn Sci 2015, 6:355–369. doi: 10.1002/wcs.1351

This article is categorized under:

Psychology > Reasoning and Decision Making

Philosophy > Foundations of Cognitive Science
Systems approaches to design of targeted therapeutic delivery
Authors: Myerson Jacob W. , Brenner Jacob S. , Greineder Colin F. , Muzykantov Vladimir R.
Published: May 2015

Targeted drug delivery aims to improve therapeutic effects and enable mechanisms that are not feasible for untargeted agents (e.g., due to impermeable biological barriers). To achieve targeting, a drug or its carrier should possess properties providing specific accumulation from circulation at the desired site. There are several examples of systems‐inspired approaches that have been applied to achieve this goal. First, proteomics analysis of plasma membrane fraction of the vascular endothelium has identified a series of target molecules and their ligands (e.g., antibodies) that deliver conjugated cargoes to well‐defined vascular cells and subcellular compartments. Second, selection of ligands binding to cells of interest using phage display libraries in vitro and in vivo has provided peptides and polypeptides that bind to normal and pathologically altered cells. Finally, large‐scale high‐throughput combinatorial synthesis and selection of lipid‐ and polymer‐based nanocarriers varying their chemical components has yielded a series of carriers accumulating in diverse organs and delivering RNA interference agents to diverse cells. Together, these approaches offer a basis for systems‐based design and selection of targets, targeting molecules, and targeting vehicles. Current studies focus on expanding the arsenal of these and alternative targeting strategies, devising drug delivery systems capitalizing on these strategies and evaluation of their benefit/risk ratio in adequate animal models of human diseases. These efforts, combined with better understanding of mechanisms and unintended consequences of these targeted interventions, need to be ultimately translated into industrial development and the clinical domain. WIREs Syst Biol Med 2015, 7:253–265. doi: 10.1002/wsbm.1304

This article is categorized under:

Laboratory Methods and Technologies > Macromolecular Interactions, Methods

Laboratory Methods and Technologies > Proteomics Methods

Translational, Genomic, and Systems Medicine > Therapeutic Methods
Risk Factors for Gambling Problems: An Analysis by Gender
Authors: Hing Nerilee , Russell Alex , Tolchard Barry , Nower Lia
Published: May 2015

Differences in problem gambling rates between males and females suggest that associated risk factors vary by gender. Previous combined analyses of male and female gambling may have obscured these distinctions. This study aimed to develop separate risk factor models for gambling problems for males and for females, and identify gender-based similarities and differences. It analysed data from the largest prevalence study in Victoria Australia (N = 15,000). Analyses determined factors differentiating non-problem from at-risk gamblers separately for women and men, then compared genders using interaction terms. Separate multivariate analyses determined significant results when controlling for all others. Variables included demographics, gambling behaviour, gambling motivations, money management, and mental and physical health. Significant predictors of at-risk status amongst female gamblers included: 18–24 years old, not speaking English at home, living in a group household, unemployed or not in the workforce, gambling on private betting, electronic gaming machines (EGMs), scratch tickets or bingo, and gambling for reasons other than social reasons, to win money or for general entertainment. For males, risk factors included: 18–24 years old, not speaking English at home, low education, living in a group household, unemployed or not in the workforce, gambling on EGMs, table games, races, sports or lotteries, and gambling for reasons other than social reasons, to win money or for general entertainment. High risk groups requiring appropriate interventions comprise young adults, especially males; middle-aged female EGM gamblers; non-English speaking populations; frequent EGM, table games, race and sports gamblers; and gamblers motivated by escape.
XRD, SEM, and XPS Analysis of Soybean Protein Powders Obtained Through Extraction Involving Reverse Micelles
Authors: Zhao Xiaoyan , Zhu Haitao , Zhang Bingwen , Chen Jun , Ao Qiang , Wang Xiyuan
Published: May 2015

Soybean protein powders obtained by aqueous buffer and reverse micelle extractions were examined and characterized using X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and scanning electron microscopy (SEM). These analysis methods provided detailed information about elemental distributions, surface structure, and secondary and microstructures of the protein, respectively. XPS data revealed that the O and N atomic percentages of soybean protein surfaces obtained with bis(2‐ethylhexyl) sodium sulfosuccinate (AOT)/hexane reverse micelles were higher than those obtained with aqueous buffer, whereas the percentage of atomic C was lower. The ratios of nitrogen to carbon (N/C) on the surface of soybean protein obtained through the two extraction methods were similar. The O/C ratio for soybean protein obtained from AOT reverse micelles was large. The obtained results indicated that the reverse micelles could affect the C, O, and N components on the surface of soybean proteins. Moreover, XRD and SEM results also showed the influence of AOT reverse micelles, which lead to more β‐sheet and pore structures.
The Evolution of Occupational Segregation in the United States, 1940–2010: Gains and Losses of Gender–Race/Ethnicity Groups
Authors: del Río Coral , Alonso-Villar Olga
Published: May 2015

The aim of this article is twofold: (1) to descriptively explore the evolution of occupational segregation of women and men of different racial/ethnic groups in the United States during 1940–2010, and (2) to assess the consequences of segregation for each group. For that purpose, in this article, we propose a simple index that measures the monetary loss or gain of a group derived from its overrepresentation in some occupations and underrepresentation in others. This index has a clear economic interpretation. It represents the per capita advantage (if the index is positive) or disadvantage (if the index is negative) of the group, derived from its segregation, as a proportion of the average wage of the economy. Our index is a helpful tool not only for academics but also for institutions concerned with inequalities among demographic groups because it makes it possible to rank them according to their segregational nature.
Eye opener: exploring complexity using rich pictures
Authors: Sayra Cristancho Sayra
Published: May 2015

Historically, approaches to exploring complexity have mainly focused on the notion that complex problems must be deconstructed into simpler parts if we are to make sense of them; this is the so-called reductionist approach. When dealing with the complexity of human experience, however, deconstructing the experience without diminishing it is a daunting, perhaps impossible task. Researchers wishing to make sense of complex experiences often begin by interviewing the individuals at the centre of those experiences. But interviews can be frustratingly limited. Visual methods, such as drawings, are beginning to show promise for designing research that taps into the complexity of professional practice. The promise of visual methods may relate to a key notion in complexity research: ‘disruptions’. In this paper I introduce the notion of ‘disruptions’ as articulated by complexity approaches from ‘systems engineering’ and suggest ‘rich pictures’ as an effective visual method to describe and understand complex problems in medical education research.
Reducing systems protecting the bacterial cell envelope from oxidative damage
Authors: Arts Isabelle S. , Gennaris Alexandra , Collet Jean-François
Published: May 2015

Exposure of cells to elevated levels of reactive oxygen species (ROS) damages DNA, membrane lipids and proteins, which can potentially lead to cell death. In proteins, the sulfur‐containing residues cysteine and methionine are particularly sensitive to oxidation, forming sulfenic acids and methionine sulfoxides, respectively. The presence of protection mechanisms to scavenge ROS and repair damaged cellular components is therefore essential for cell survival. The bacterial cell envelope, which constitutes the first protection barrier from the extracellular environment, is particularly exposed to the oxidizing molecules generated by the host cells to kill invading microorganisms. Therefore, the presence of oxidative stress defense mechanisms in that compartment is crucial for cell survival. Here, we review recent findings that led to the identification of several reducing pathways protecting the cell envelope from oxidative damage. We focus in particular on the mechanisms that repair envelope proteins with oxidized cysteine and methionine residues and we discuss the major questions that remain to be solved.
Transforming growth factor β and bone morphogenetic protein actions in brain tumors
Authors: Caja Laia , Bellomo Claudia , Moustakas Aristidis
Published: May 2015

Members of the transforming growth factor β (TGF‐β) family are implicated in the biology of several cancers. Here we focus on malignancies of the brain and examine the TGFβ and the bone morphogenetic protein (BMP) signaling branches of the family. These pathways exhibit context‐dependent actions during tumorigenesis, acting either as tumor suppressors or as pro‐tumorigenic agents. In the brain, the TGF‐βs associate with oncogenic development and progression to the more malignant state. Inversely, the BMPs suppress tumorigenic potential by acting as agents that induce tumor cell differentiation. The latter has been best demonstrated in grade IV astrocytomas, otherwise known as glioblastoma multiforme. We discuss how the actions of TGF‐βs and BMPs on cancer stem cells may explain their effects on tumor progression, and try to highlight intricate mechanisms that may link tumor cell differentiation to invasion. The focus on TGF‐β and BMP and their actions in brain malignancies provides a rich territory for mechanistic understanding of tumor heterogeneity and suggests ways for improved therapeutic intervention, currently being addressed by clinical trials.
Oncolytic vaccinia virus synergizes with irinotecan in colorectal cancer
Authors: Ottolino-Perry Kathryn , Acuna Sergio A. , Angarita Fernando A. , Sellers Clara , Zerhouni Siham , Tang Nan , McCart J. Andrea
Published: May 2015

Metastatic colorectal cancer (CRC) is complex clinical challenge for which there are limited treatment options. Chemotherapy with or without surgery provides moderate improvements in overall survival and quality of life; nevertheless the 5‐year survival remains below 30%. Oncolytic vaccinia virus (VV) shows strong anti‐tumour activity in models of CRC, however transient delays in disease progression are insufficient to lead to long‐term survival. Here we examined the efficacy of VV with oxaliplatin or SN‐38 (active metabolite of irinotecan) in CRC cell lines in vitro and VV with irinotecan in an orthotopic model of metastatic CRC. Synergistic improvements in in vitro cell killing were observed in multiple cell lines. Combination therapy was well tolerated in tumour‐bearing mice and the median survival was significantly increased relative to monotherapy despite a drug‐dependent decrease in the mean tumour titer. Increased apoptosis following in vitro and in vivo combination therapy was observed. In vitro cell cycle analysis showed increases in S‐phase cells following infection occurred in both infected and uninfected cell populations. This corresponded to a 4‐fold greater increase in apoptosis in the uninfected compared to infected cells following combination therapy. Combination treatment strategies are among the best options for patients with advanced cancers. VV is currently under clinical investigation in patients with CRC and the data presented here suggest that its combination with irinotecan may provide benefit to a subset of CRC patients. Further, investigation of this combination is necessary to determine the tumour characteristics responsible for mediating synergy.
Middle Holocene environmental change in central Korea and its linkage to summer and winter monsoon changes
Authors: Lim Jaesoo , Yang Dong-Yoon , Lee Jin-Young , Hong Sei-Sun , Um In Kwon
Published: May 2015

To trace the surficial responses of lowlands to past climate change, we investigated δ13C in total organic carbon (TOC), C/N ratios, magnetic susceptibility (MS), and silicon (Si) intensity (directly proportional to concentration) in wetland sediments collected from the Gimpo area of central Korea, covering 6600–4600 cal yr BP. Two organic layers with high TOC%, negatively depleted δ13CTOC values (− 27 to − 29‰), low MS values, and low Si intensities were found at 6200–5900 and 5200–4800 cal yr BP, respectively. These middle Holocene wet periods corresponded to relatively intensified summer monsoon and solar activity periods. The intervening dry period (5900–5200 cal yr BP) with high MS, high Si, and low TOC% corresponded to an intensified dust-activity interval and stronger winter monsoon. This multi-centennial climatic fluctuation of wet periods (6200–5900 cal yr BP and 5200–4800 cal yr BP) and an intervening dry period (5900–5200 cal yr BP) in central Korea was more synchronous with climate change in the arid inner part of China than with that in South China, suggesting possible strong high-latitude-driven climatic influences (e.g., North Atlantic cooling events) during the middle Holocene.
Rapid and selective manipulation of milk fatty acid composition in mice through the maternal diet during lactation
Authors: Oosting Annemarie , Verkade Henkjan J. , Kegler Diane , van de Heijning Bert J. M. , van der Beek Eline M.
Published: May 2015

Dietary fatty acid (FA) composition in early postnatal life can modulate growth and development and later metabolic health. Investigating programming effects of early dietary FA manipulations in rodents may be stressful and complicated due to the need of artificial feeding techniques. It is largely unknown to what extent breast milk (BM) FA composition can be directly manipulated by the diet. We exposed dams to different dietary FA compositions from postnatal day (PN) 2 until PN28. Dams with litters were randomly assigned to control (CTRL), high-medium-chain FA (MCFA), low-linoleic acid (LowLA), high-n-3 long-chain PUFA (n-3LCP) or high-n-3LCP and MCFA (n-3LCP/MCFA) diets, and diets were continued after weaning until PN28. FA compositions were determined in feeds, milk and in erythrocytes. BM MCFA content was independent from dietary MCFA intake. In contrast, the LowLA diet reduced BM LA content by about 50 % compared with the CTRL diet at PN7. BM of dams fed then-3LCP orn-3LCP/MCFA diet contained about 6-fold moren-3 LCP than BM of the dams fed the CTRL diet at PN7. These changes in milk FA composition established after 5 d of dietary exposure did not further change over the lactation period. At PN28, the erythrocyte FA composition of the male pups correlated with analysed milk FA profiles. In conclusion, manipulation of the diet of lactating mice can strongly and rapidly affect BM FA composition, in particular ofn-6 LA andn-3 LCP. Our present findings will facilitate mechanistic studies on the programming of adult metabolic health by dietary FA in the early postnatal period via direct and selective manipulation of the maternal diet.
Dietary patterns and their associations with childhood obesity in China
Authors: Zhang Jiguo , Wang Huijun , Wang Youfa , Xue Hong , Wang Zhihong , Du Wenwen , Su Chang , Zhang Ji , Jiang Hongru , Zhai Fengying , Zhang Bing
Published: May 2015

Dietary patterns represent the combined effects of foods, and illustrate efficaciously the impact of diet on health outcomes. Some findings of previous studies have limited applicability to Chinese children due to cultural factors. The presnt study was designed to identify dietary patterns and determine their relationships with obesity among Chinese children and adolescents. Data collected from 1282 children and adolescents aged 7–17 years from the 2011 China Health and Nutrition Survey (CHNS) were used. Dietary patterns were identified using factor analysis of data from three consecutive 24-h dietary recalls. Weight and height were measured following standard methods, and BMI was calculated. Three dietary patterns were identified: modern (high intakes of milk, fast foods and eggs), traditional north (high intakes of wheat, tubers and other cereals) and traditional south (high intakes of vegetables, rice and pork). After adjusting for some confounders and total energy intake, subjects in the highest quartiles of the modern and traditional north patterns were found to have significantly greater risk of obesity (OR 3·10, 95 % CI 1·52, 6·32, and OR 2·42, 95 % CI 1·34, 4·39, respectively). In conclusion, the modern dietary pattern and the traditional north dietary pattern were associated with higher risk of obesity. Promoting healthier eating patterns could help prevent obesity in Chinese children.
Canadian power mobility device users' experiences of ageing with mobility impairments
Authors: KOROTCHENKO ALEXANDRA , HURD CLARKE LAURA
Published: May 2015

In this article, we draw upon interviews with 14 men and 15 women aged 51–92 to examine the embodied experiences of Canadian power mobility device users. In particular, we investigate how individuals ageing with mobility impairments perceived and experienced the practical impacts and symbolic cultural connotations of utilising a power mobility device. Our findings reveal that those participants who had begun to use their power mobility devices later in life were dismayed by and apprehensive about the significance of their diminishing physical abilities in the context of the societal privileging of youthful and able bodies. At the same time, the participants who had used a power mobility device from a young age were fearful of prospective bodily declines, and discussed the significance and consequences of being unable to continue to operate their power mobility devices autonomously in the future. We consider the ways in which the participants attempted to manage, mitigate and reframe their experiences of utilising power mobility devices in discriminatory environments. We discuss our findings in relation to on-going theoretical debates pertaining to the concepts of ‘biographical disruption’ and the third and fourth ages.
Prenatal tobacco exposure and self-regulation in early childhood: Implications for developmental psychopathology
Authors: Wiebe Sandra A. , Clark Caron A. C. , De Jong Desiree M. , Chevalier Nicolas , Espy Kimberly Andrews , Wakschlag Lauren
Published: May 2015

Prenatal tobacco exposure (PTE) has a well-documented association with disruptive behavior in childhood, but the neurocognitive effects of exposure that underlie this link are not sufficiently understood. The present study was designed to address this gap, through longitudinal follow-up in early childhood of a prospectively enrolled cohort with well-characterized prenatal exposure. Three-year-old children (n= 151) were assessed using a developmentally sensitive battery capturing both cognitive and motivational aspects of self-regulation. PTE was related to motivational self-regulation, where children had to delay approach to attractive rewards, but not cognitive self-regulation, where children had to hold information in mind and inhibit prepotent motor responses. Furthermore, PTE predicted motivational self-regulation more strongly in boys than in girls, and when propensity scores were covaried to control for confounding risk factors, the effect of PTE on motivational self-regulation was significant only in boys. These findings suggest that PTE's impact on neurodevelopment may be greater in boys than in girls, perhaps reflecting vulnerability in neural circuits that subserve reward sensitivity and emotion regulation, and may also help to explain why PTE is more consistently related to disruptive behavior disorders than attention problems.
Brain adaptation and alternative developmental trajectories
Authors: Johnson Mark H. , Jones Emily J. H. , Gliga Teodora
Published: May 2015

Resilience and adaptation in the face of early genetic or environmental risk has become a major interest in child psychiatry over recent years. However, we still remain far from an understanding of how developing human brains as a whole adapt to the diffuse and widespread atypical synaptic function that may be characteristic of some common developmental disorders. The first part of this paper discusses four types of whole-brain adaptation in the face of early risk: redundancy, reorganization, niche construction, and adjustment of developmental rate. The second part of the paper applies these adaptation processes specifically to autism. We speculate that key features of autism may be the end result of processes of early brain adaptation, rather than the direct consequences of ongoing neural pathology.
Neural plasticity and the development of attention: Intrinsic and extrinsic influences
Authors: Swingler Margaret M. , Perry Nicole B. , Calkins Susan D.
Published: May 2015

The development of attention has been strongly linked to the regulation of emotion and behavior and has therefore been of particular interest to researchers aiming to better understand precursors to behavioral maladjustment. In the current paper, we utilize a developmental psychopathology and neural plasticity framework to highlight the importance of both intrinsic (i.e., infant neural functioning) and extrinsic (i.e., caregiver behavior) factors for the development of attentional control across the first year. We begin by highlighting the importance of attention for children's emotion regulation abilities and mental health. We then review the development of attention behavior and underscore the importance of neural development and caregiver behavior for shaping attentional control. Finally, we posit that neural activation associated with the development of the executive attention network may be one mechanism through which maternal caregiving behavior influences the development of infants’ attentional control and subsequent emotion regulation abilities known to be influential to childhood psychopathology.
Developmental psychopathology in an era of molecular genetics and neuroimaging: A developmental neurogenetics approach
Authors: Hyde Luke W.
Published: May 2015

The emerging field of neurogenetics seeks to model the complex pathways from gene to brain to behavior. This field has focused on imaging genetics techniques that examine how variability in common genetic polymorphisms predict differences in brain structure and function. These studies are informed by other complimentary techniques (e.g., animal models and multimodal imaging) and have recently begun to incorporate the environment through examination of Imaging Gene × Environment interactions. Though neurogenetics has the potential to inform our understanding of the development of psychopathology, there has been little integration between principles of neurogenetics and developmental psychopathology. The paper describes a neurogenetics and Imaging Gene × Environment approach and how these approaches have been usefully applied to the study of psychopathology. Six tenets of developmental psychopathology (the structure of phenotypes, the importance of exploring mechanisms, the conditional nature of risk, the complexity of multilevel pathways, the role of development, and the importance of who is studied) are identified, and how these principles can further neurogenetics applications to understanding the development of psychopathology is discussed. A major issue of this piece is how neurogenetics and current imaging and molecular genetics approaches can be incorporated into developmental psychopathology perspectives with a goal of providing models for better understanding pathways from among genes, environments, the brain, and behavior.
Dysplasticity, metaplasticity, and schizophrenia: Implications for risk, illness, and novel interventions
Authors: Keshavan Matcheri S. , Mehta Urvakhsh Meherwan , Padmanabhan Jaya L. , Shah Jai L.
Published: May 2015

In this paper, we review the history of the concept of neuroplasticity as it relates to the understanding of neuropsychiatric disorders, using schizophrenia as a case in point. We briefly review the myriad meanings of the term neuroplasticity, and its neuroscientific basis. We then review the evidence for aberrant neuroplasticity and metaplasticity associated with schizophrenia as well as the risk for developing this illness, and discuss the implications of such understanding for prevention and therapeutic interventions. We argue that the failure and/or altered timing of plasticity of critical brain circuits might underlie cognitive and deficit symptoms, and may also lead to aberrant plastic reorganization in other circuits, leading to affective dysregulation and eventually psychosis. This “dysplastic” model of schizophrenia can suggest testable etiology and treatment-relevant questions for the future.
Beyond Static Models: An Evaluation of Present Status and Future Prospects for Iron Age Research in Southern Africa
Authors: Fredriksen Per Ditlef , Chirikure Shadreck
Published: May 2015

To what extent do we need structuralist cognitive settlement models such as the Central Cattle Pattern and the Zimbabwe Pattern for future research and understanding of Iron Age social life in southern Africa? How will alternative approaches enable us to progress beyond the present status of knowledge? While the three last decades of debate have underpinned key aspects of archaeological inquiry, notably questions of social change, gender dynamics, analytical scale and the use of ethnographic and ethnoarchaeological insights, the sometimes entrenched nature of the debate has in other respects hindered development of new approaches and restrained the range of themes and topics scholars engage with. In this article, we identify the issues of analytical scale and recursiveness as key to the development of future approaches and present an alternative framework through empirically grounded discussion of three central Iron Age themes: ceramics and the microscale, the spatiality of metal production and the temporality of stonewalled architecture.
Generalizations of the distributed Deutsch–Jozsa promise problem
Authors: GRUSKA JOZEF , QIU DAOWEN , ZHENG SHENGGEN
Published: May 2015

In thedistributed Deutsch–Jozsa promise problem, two parties are to determine whether their respective stringsx, y∈ {0,1}nare at theHamming distanceH(x, y) = 0 orH(x, y) =$\frac{n}{2}$. Buhrmanet al.(STOC' 98) proved that the exactquantum communication complexityof this problem isO(logn) while thedeterministic communication complexityisΩ(n). This was the first impressive (exponential) gap between quantum and classical communication complexity. In this paper, we generalize the above distributed Deutsch–Jozsa promise problem to determine, for any fixed$\frac{n}{2}$⩽k⩽n, whetherH(x, y) = 0 orH(x, y) =k, and show that an exponential gap between exact quantum and deterministic communication complexity still holds ifkis an even such that$\frac{1}{2}$n⩽k< (1 − λ)n, where 0 < λ <$\frac{1}{2}$is given. We also deal with a promise version of the well-knowndisjointnessproblem and show also that for this promise problem there exists an exponential gap between quantum (and also probabilistic) communication complexity and deterministic communication complexity of the promise version of such a disjointness problem. Finally, some applications to quantum, probabilistic and deterministic finite automata of the results obtained are demonstrated.