bluuebunny/crossref_metadata_2025 huggingface dataset:
Epigenetics, fragile X syndrome and transcriptional therapy
Authors: Tabolacci Elisabetta , Chiurazzi Pietro
Published: October 2013

Epigenetics refers to the study of heritable changes in gene expression that occur without a change in DNA sequence. Epigenetic mechanisms therefore include all transcriptional controls that determine how genes are expressed during development and differentiation, but also in individual cells responding to environmental stimuli. The purpose of this review is to examine the basic principles of epigenetic mechanisms and their contribution to human disorders with a particular focus on fragile X syndrome (FXS), the most common monogenic form of developmental cognitive impairment. FXS represents a prototype of the so‐called repeat expansion disorders due to “dynamic” mutations, namely the expansion (known as “full mutation”) of a CGG repeat in the 5′UTR of the FMR1 gene. This genetic anomaly is accompanied by epigenetic modifications (mainly DNA methylation and histone deacetylation), resulting in the inactivation of the FMR1 gene. The presence of an intact FMR1 coding sequence allowed pharmacological reactivation of gene transcription, particularly through the use of the DNA demethylating agent 5′‐aza‐2′‐deoxycytydine and/or inhibitors of histone deacetylases. These treatments suggested that DNA methylation is dominant over histone acetylation in silencing the FMR1 gene. The importance of DNA methylation in repressing FMR1 transcription is confirmed by the existence of rare unaffected males carrying unmethylated full mutations. Finally, we address the potential use of epigenetic approaches to targeted treatment of other genetic conditions. © 2013 Wiley Periodicals, Inc.
Developmental disease and cancer: Biological and clinical overlaps
Authors: Bellacosa Alfonso
Published: October 2013

Numerous parallelisms exist between development and cancer. In this article, I review some of the founding ideas linking development and cancer, and highlight clinical conditions exhibiting features of both developmental derangement and cancer predisposition, including cohesinopathies, rasopathies, phakomatoses, Proteus syndrome and other overgrowth disorders, recessive chromosome breakage syndromes, and dominant hereditary cancer syndromes. I suggest that these disorders encompass a continuous spectrum spanning clinical genetics and clinical oncology, and derive some general implications that might be useful in the future for the treatment of these diseases. © 2013 Wiley Periodicals, Inc.
Understanding the basis of auriculocondylar syndrome: Insights from human, mouse and zebrafish genetic studies
Authors: Clouthier David E. , Passos‐Bueno Maria Rita , Tavares Andre L.P. , Lyonnet Stanislas , Amiel Jeanne , Gordon Christopher T.
Published: October 2013

Among human birth defect syndromes, malformations affecting the face are perhaps the most striking due to cultural and psychological expectations of facial shape. One such syndrome is auriculocondylar syndrome (ACS), in which patients present with defects in ear and mandible development. Affected structures arise from cranial neural crest cells, a population of cells in the embryo that reside in the pharyngeal arches and give rise to most of the bone, cartilage and connective tissue of the face. Recent studies have found that most cases of ACS arise from defects in signaling molecules associated with the endothelin signaling pathway. Disruption of this signaling pathway in both mouse and zebrafish results in loss of identity of neural crest cells of the mandibular portion of the first pharyngeal arch and the subsequent repatterning of these cells, leading to homeosis of lower jaw structures into more maxillary‐like structures. These findings illustrate the importance of endothelin signaling in normal human craniofacial development and illustrate how clinical and basic science approaches can coalesce to improve our understanding of the genetic basis of human birth defect syndromes. Further, understanding the genetic basis for ACS that lies outside of known endothelin signaling components may help elucidate unknown aspects critical to the establishment of neural crest cell patterning during facial morphogenesis. © 2013 Wiley Periodicals, Inc.
Developmental disorders of the dentition: An update
Authors: Klein Ophir D. , Oberoi Snehlata , Huysseune Ann , Hovorakova Maria , Peterka Miroslav , Peterkova Renata
Published: October 2013

Dental anomalies are common congenital malformations that can occur either as isolated findings or as part of a syndrome. This review focuses on genetic causes of abnormal tooth development and the implications of these abnormalities for clinical care. As an introduction, we describe general insights into the genetics of tooth development obtained from mouse and zebrafish models. This is followed by a discussion of isolated as well as syndromic tooth agenesis, including Van der Woude syndrome (VWS), ectodermal dysplasias (EDs), oral‐facial‐digital (OFD) syndrome type I, Rieger syndrome, holoprosencephaly, and tooth anomalies associated with cleft lip and palate. Next, we review delayed formation and eruption of teeth, as well as abnormalities in tooth size, shape, and form. Finally, isolated and syndromic causes of supernumerary teeth are considered, including cleidocranial dysplasia and Gardner syndrome. © 2013 Wiley Periodicals, Inc.
Nickel‐Catalyzed Cyclizative trans‐Carboboration of Alkynes through Activation of Boron–Chlorine Bonds by Using Organometallic Reagents as Donors of Organic Groups
Authors: Daini Masaki , Yamamoto Akihiko , Suginome Michinori
Published: October 2013

Cyclizative alkynylboration and alkenylboration of carbon–carbon triple bonds proceeds in the presence of a nickel catalyst. Chloroboranes bearing homopropargyloxy or bishomopropargyloxy groups were used as substrates with alkynylstannane, vinylstannane, and alkenylzirconium reagents as donors of organic groups. The reaction mechanism may involve the following elementary steps: oxidative addition of the BCl bond to a nickel(0) catalyst, insertion of the triple bond into the NiB bond, Z‐to‐E isomerization of the alkenylnickel intermediate, transmetalation from organostannane or organozirconium reagents, and reductive elimination of the BC bond. An intermediary nickel complex was isolated and identified by a single‐crystal X‐ray analysis.
Local knowledge and perceptions of chimpanzees in Cantanhez National Park, Guinea‐Bissau
Authors: Sousa Joana , Vicente Luís , Gippoliti Spartaco , Casanova Catarina , Sousa Cláudia
Published: October 2013

Our study concerns local knowledge and perceptions of chimpanzees among farming communities within Cantanhez National Park, Guinea‐Bissau. We submitted a survey questionnaire to 100 people living in four villages in the Park to enquire about their knowledge of chimpanzee ecology and human–chimpanzee interactions. Local farmers live in close contact with chimpanzees, consider them to be more similar to humans than any other species, and attribute special importance to them primarily due to expectations of tourism revenue. Interviewees' responses, as a function of gender, village, and age, were analyzed statistically using non‐parametric tests (Mann–Whitney and Kruskal–Wallis). Age influenced responses significantly, while gender and village had no significant effect. Youngsters emphasized morphological aspects of human–chimpanzee similarities, while adults emphasized chimpanzee behavior and narratives about the shared history of humans and chimpanzees. Tourism, conservation, and crop raiding feature prominently in people's reports about chimpanzees. Local people's engagement with conservation and tourism‐related activities is likely to allow them to manage not only the costs but also the benefits of conservation, and can in turn inform the expectations built upon tourism. Am. J. Primatol. 76:122–134, 2014. © 2013 Wiley Periodicals, Inc.
Factors increasing snake detection and perceived threat in captive rhesus macaques (Macaca mulatta)
Authors: Etting Stephanie F. , Isbell Lynne A. , Grote Mark N.
Published: October 2013

The primary predators of primates are all ambush hunters, and yet felids, raptors, and snakes differ in aspects of their ecology that affect the evasive strategies of their primate prey. Felids and raptors can traverse long distances quickly, thus the urgency of threat they present increases as they come closer in proximity to primates. In contrast, snakes do not move rapidly over long distances, and so primates may be reasonably safe even at close distances provided snakes can be detected and monitored. We investigated the ability of captive rhesus macaques (Macaca mulatta) to detect snakes at distances ranging from 15 to 1.5 m. We also examined variation in intensity of perceived threat by applying a Hidden Markov Model to infer changes in underlying state from observable behaviors, that is, increased attention and mobbing. We found that the macaques often failed to detect snake models but that closer proximity improved snake detection, which is necessary before threat can be perceived. We also found that having only one individual in fairly close proximity (≤7.5 m) was sufficient to alert the rest of the group and so the chances of detection did not increase with increasing group size. Finally, we found that when the snakes were perceived, they did not elicit greater intensity of response with closer proximity. These results provide evidence that the threat from snakes is greatest when they are in proximity to primates but are unseen. When snakes are seen, however, distance appears not to affect primates' perceived risk, in contrast to their perceived risk from raptors and felids. Am. J. Primatol. 76:135–145, 2014. © 2013 Wiley Periodicals, Inc.
Vocal acoustics in the endangered proboscis monkey (Nasalis larvatus)
Authors: Röper K.M. , Scheumann M. , Wiechert A.B. , Nathan S. , Goossens B. , Owren M.J. , Zimmermann E.
Published: October 2013

The endangered proboscis monkey (Nasalis larvatus) is a sexually highly dimorphic Old World primate endemic to the island of Borneo. Previous studies focused mainly on its ecology and behavior, but knowledge of its vocalizations is limited. The present study provides quantified information on vocal rate and on the vocal acoustics of the prominent calls of this species. We audio‐recorded vocal behavior of 10 groups over two 4‐month periods at the Lower Kinabatangan Wildlife Sanctuary in Sabah, Borneo. We observed monkeys and recorded calls in evening and morning sessions at sleeping trees along riverbanks. We found no differences in the vocal rate between evening and morning observation sessions. Based on multiparametric analysis, we identified acoustic features of the four common call‐types “shrieks,” “honks,” “roars,” and “brays.” “Chorus” events were also noted in which multiple callers produced a mix of vocalizations. The four call‐types were distinguishable based on a combination of fundamental frequency variation, call duration, and degree of voicing. Three of the call‐types can be considered as “loud calls” and are therefore deemed promising candidates for non‐invasive, vocalization‐based monitoring of proboscis monkeys for conservation purposes. Am. J. Primatol. 76:192–201, 2014. © 2013 Wiley Periodicals, Inc.
Technical Note: Geometric morphometrics and sexual dimorphism of the greater sciatic notch in adults from two skeletal collections: The accuracy and reliability of sex classification
Authors: Velemínská Jana , Krajíček Václav , Dupej Ján , Goméz‐Valdés Jorge A. , Velemínský Petr , Šefčáková Alena , Pelikán Josef , Sánchez‐Mejorada Gabriela , Brůžek Jaroslav
Published: October 2013

The greater sciatic notch (GSN) is one of the most important and frequently used characteristics for determining the sex of skeletons, but objective assessment of this characteristic is not without its difficulties. We tested the robustness of GSN sex classification on the basis of geometric morphometrics (GM) and support vector machines (SVM), using two different population samples. Using photographs, the shape of the GSN in 229 samples from two assemblages (documented collections of a Euroamerican population from the Maxwell Museum, University of New Mexico, and a Hispanic population from Universidad Nacional Autónoma de México, Mexico City) was segmented automatically and evaluated using six curve representations. The optimal dimensionality for each representation was determined by finding the best sex classification. The classification accuracy of the six curve representations in our study was similar but the highest and concurrently homologous cross‐validated accuracy of 92% was achieved for a pooled sample using Fourier coefficient and Legendre polynomial methods. The success rate of our classification was influenced by the number of semilandmarks or coefficients and was only slightly affected by GSN marginal point positions. The intrapopulation variability of the female GSN shape was significantly lower compared with the male variability, possibly as a consequence of the intense selection pressure associated with reproduction. Males were misclassified more often than females. Our results show that by using a suitable GSN curve representation, a GM approach, and SVM analysis, it is possible to obtain a robust separation between the sexes that is stable for a multipopulation sample. Am J Phys Anthropol 152:558‐565, 2013. © 2013 Wiley Periodicals, Inc.
Trans‐synaptic axonal degeneration in the visual pathway in multiple sclerosis
Authors: Gabilondo Iñigo , Martínez‐Lapiscina Elena H. , Martínez‐Heras Eloy , Fraga‐Pumar Elena , Llufriu Sara , Ortiz Santiago , Bullich Santiago , Sepulveda Maria , Falcon Carles , Berenguer Joan , Saiz Albert , Sanchez‐Dalmau Bernardo , Villoslada Pablo
Published: October 2013

Objective

To evaluate the association between the damage to the anterior and posterior visual pathway as evidence of the presence of retrograde and anterograde trans‐synaptic degeneration in multiple sclerosis (MS).

Methods

We performed a longitudinal evaluation on a cohort of 100 patients with MS, acquiring retinal optical coherence tomography to measure anterior visual pathway damage (peripapillary retinal nerve fiber layer [RNFL] thickness and macular volume) and 3T brain magnetic resonance imaging (MRI) for posterior visual pathway damage (volumetry and spectroscopy of visual cortex, lesion volume within optic radiations) at inclusion and after 1 year. Freesurfer and SPM8 software was used for MRI analysis. We evaluated the relationships between the damage in the anterior and posterior visual pathway by voxel‐based morphometry (VBM), multiple linear regressions, and general linear models.

Results

VBM analysis showed that RNFL thinning was specifically associated with atrophy of the visual cortex and with lesions in optic radiations at study inclusion (p < 0.05). Visual cortex volume (β = +0.601, 95% confidence interval [CI] = +0.04 to +1.16), N‐acetyl aspartate in visual cortex (β = +1.075, 95% CI = +0.190 to +1.961), and lesion volume within optic radiations (β = −2.551, 95% CI = −3.910 to −1.192) significantly influenced average RNFL thinning at study inclusion independently of other confounders, especially optic neuritis (ON). The model indicates that a decrease of 1cm3 in visual cortex volume predicts a reduction of 0.6μm in RNFL thickness. This association was also observed after 1 year of follow‐up. Patients with severe prior ON (adjusted difference = −3.01, 95% CI = −5.08 to −0.95) and mild prior ON (adjusted difference = −1.03, 95% CI = −3.02 to +0.95) had a lower adjusted mean visual cortex volume than patients without ON.

Interpretation

Our results suggest the presence of trans‐synaptic degeneration as a contributor to chronic axon damage in MS. ANN NEUROL 2014;75:98–107
Nodal theorems for the Dirac equation in d ≥ 1 dimensions
Authors: Hall Richard L. , Zorin Petr
Published: October 2013

A single particle obeys the Dirac equation in spatial dimensions and is bound by an attractive central monotone potential that vanishes at infinity. In one dimension, the potential is even, and monotone for The asymptotic behavior of the wave functions near the origin and at infinity are discussed. Nodal theorems are proven for the cases and , which specify the relationship between the numbers of nodes n1 and n2 in the upper and lower components of the Dirac spinor. For , whereas for if and if where and This work generalizes the classic results of Rose and Newton in 1951 for the case Specific examples are presented with graphs, including Dirac spinor orbits
Observational effects from quantum cosmology
Authors: Calcagni Gianluca
Published: October 2013

This erratum is published to correct equations , and of the article by G. Calcagni [DOI http://dx.doi.org/10.1002/andp.201200227, published in Ann. Phys. (Berlin) 525, 323–338 (2013)].
Rationales Design von effizienten organischen strukturdirigierenden Reagentien für die Zeolithsynthese
Authors: Moliner Manuel , Rey Fernando , Corma Avelino
Published: October 2013

Zeolithe sind kristalline mikroporöse Materialien, die über einen großen Anwendungsbereich verfügen, insbesondere in der Katalyse. Ein aktuelles Forschungsinteresse besteht darin, gezielt Zeolithe mit gewünschten physikalisch‐chemischen Eigenschaften für eine bestimmte katalytische Anwendung herzustellen. Dies ermöglicht, die Effizienz des gesamten chemischen Prozesses zu steigern, und führt beispielsweise zu höheren Ausbeuten, weniger Nebenprodukten, geringerem Energieverbrauch und Kostenminimierung. Die Steuerung der Kristallisationsprozesse zur Bildung von Materialien mit gewünschter Gerüsttopologie, Kristallgröße oder chemischer Zusammensetzung wird dadurch erschwert, dass etliche Variablen sowohl die Keimbildung als auch den Kristallisationsprozess beeinflussen. Die Kombination aus vorhandenem Wissen sowie Konzeption und Innovation der Synthesestrategien hat in den letzten Jahren einzigartige Zeolithstrukturen hervorgebracht. Dies ist insbesondere im Hinblick auf die Gestaltung der organischen und anorganischen strukturdirigierenden Reagentien (SDA) zutreffend. In diesem Kurzaufsatz erläutern wir die Prinzipien, denen wir bei unseren Studien zur Synthese neuer Zeolithstrukturen gefolgt sind. Die Diskussion wird in den Gesamtkontext literaturbekannter Methoden eingebettet und zu den Fortschritten der letzten Jahre auf dem Gebiet der Zeolith‐Forschung in Beziehung gesetzt.
Effects of mesh grid and turbulence models on heat transfer coefficient in a convergent–divergent nozzle
Authors: Zhalehrajabi Ehsan , Rahmanian Nejat , Hasan Nurul
Published: October 2013

The results of computational fluid dynamics simulation for convective heat transfer of turbulent flow in a cooled convergent–divergent nozzle are reported. The importance of the heat transfer coefficient is to find the most suitable metals for the nozzle wall as well as its application for producing nano‐particles. ansys‐icem and ansys‐cfx 13.0 are used to mesh and simulate fluid flow in the nozzle, respectively. Effects of grid resolution and different turbulence models on the heat transfer coefficient are investigated. Three turbulence models of k‐ω, k‐ε and shear stress transport are applied to calculate the heat transfer coefficient. Stagnation absolute pressure and temperature are 10.3 bara and 840 K, respectively, the same as those in the experimental work. The heat transfer coefficients obtained from simulation are compared with the available experimental data in literature to find out the best suitable mesh grid and the turbulence model. Under the selected operating conditions, k‐ε and k‐ω models have shown the best agreement with the experimental data with the average error of 6.5% and 10%, respectively, while shear stress transport under predicts the values with 16% error. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.
Study on deactivation of the CuO‐NiO/γ‐Al2O3 catalyst in the synthesis of N‐alkylmorpholines
Authors: Luo Chenxi , Qian Chao , Luo Hu , Feng Lie , Chen Yunbin , Chen Xinzhi
Published: October 2013

The performance of the CuO‐NiO/γ‐Al2O3 catalyst used in the synthesis of N‐alkylmorpholines from diethylene glycol, alcohol, and ammonia was studied. The catalyst was prepared with Ni and Cu as the active components, and the optimum contents were 4.2–4.4% and 16.8–18.9%, respectively. The catalytic activity decreased rapidly as the catalyst deactivated gradually under the high temperature and liquid hourly space velocity reaction condition. The fresh and deactivated catalysts were characterized by inductively coupled plasma atomic emission spectrometry, scanning electron microscope, X‐ray diffraction, thermo gravimetric analyzer, element analysis instrument and N2 adsorption–desorption. It was found that the catalyst was covered with carbon deposition, which stunted the active center of catalyst surface and blocked the channels of the support. In addition, the sintering of the copper crystallites resulted in reunion of active metal and reduction of the active sites. At last, the catalysts were regenerated by calcination with high temperature, and the yield of the regeneration catalytic reaction was restored to 88.9% of its original levels. Copyright © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.
Structure and properties of films fabricated from chitin solution by coagulating with heating
Authors: Duan Bo , Chang Chunyu , Zhang Lina
Published: October 2013

In the present work, chitin films were fabricated from chitin solution dissolved in 8 wt % NaOH/4 wt % urea aqueous systems at low temperature by coagulating with heating without using any coagulant. The formation of the chitin films was confirmed to be an entirely physical process, namely chitin inclusion complex associated with NaOH, urea and water in the solvent was broken by heating, leading to the aggregation of the chitin chains through the hydrogen bonding. A schematic model was proposed to describe the regeneration mechanism of the chitin, indicating the physical crosslinking and entanglement of the chitin chains to form the films. Glycerol was used as plasticizer, and with an increase of the glycerol content, the elongation at break (ɛb) of chitin films increased rapidly from 7.8 to 83.1%, whereas the tensile strength (σb) decreased from 89.3 to 51.7 MPa. This work provided a “green” pathway for the researches and developments of chitin materials. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39538.
Processing‐induced degradation of nanoclay organic modifier in melt‐mixed PET/PE blends during twin screw extrusion at industrial scale: Effect on morphology and mechanical behavior
Authors: Yousfi Mohamed , Lepretre Sophie , Soulestin Jeremie , Vergnes Bruno , Lacrampe Marie‐France , Krawczak P.
Published: October 2013

Immiscible PET/PE blends (80/20 wt %) were prepared on an industrial twin‐screw extruder with and without different types of commercially available montmorillonites (Cloisite® C15A, C10A, and 30B), containing organic surfactants differing by their polarities and their thermal stability). XRD and TEM observations evidence an intercalated structure, C15A leading to a better dispersion compared to C30B and C10A. The size of the PE dispersed phase decreases upon addition of organoclays (OMMT), suggesting an efficient compatibilization. The most efficient compatibilizing effect is observed in the case of C15A (smallest droplet size and narrowest size distribution). Nevertheless, elongation at break in tension and impact strength of PET/PE blends drastically decrease upon addition of OMMT, whatever the organoclay added, due to a possible degradation of the clay surfactant during melt compounding, which counteracts the nanofiller compatibilization effect. Furthermore, similar PET/PE/OMMT blends prepared at a lab scale using a microcompounder are ductile contrary to those compounded in the industrial extruder, which show a brittle behavior. This difference was ascribed to the extrusion residence time (much higher in an industrial extruder than in a lab micro‐compounder), which appeared to be a key parameter in controlling the clay surfactant degradation and thus the end‐use properties of such immiscible blends. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39712.
Investigation of the relationship between morphology and tribological properties of an epoxy resin based on tetraglycidyl 4,4′‐diaminodiphenylmethane modified with polyetherimide oligomers
Authors: Chen Haiming , Su Chao , Huang Ting , Li Tongsheng
Published: October 2013

In this paper, polyetherimides (PEI) with two different calculated number‐average molecular weights (Mn) of 5000 and 10,000 g/mol were synthesized and used to modify tetraglycidyl 4,4′‐diaminodiphenylmethane. Three different morphologies (separated phase, bi‐continuous phase, and phase inversion structure) were obtained by controlling molecular weights and content of PEI. Thermal and mechanical characterizations showed that addition of PEI resulted in an increase in thermal stability and tensile strength. Tensile strength of samples with bi‐continuous phase was higher than those with separated phase or phase inversion structure. Influence of morphologies on tribology properties were studied by a ring‐on‐block wear tester. Higher wear resistance was achieved from samples with bi‐continuous phase. It was found that wear life of samples with bi‐continuous phase was almost 100% higher than that of samples with separated phase. This is clearly related to the change in thermal and mechanical properties caused by the change of morphologies. Scanning electron microscope observations of worn surfaces and wear debris of the tested samples showed that tribological behaviors and wear mechanisms were heavily dependent on morphologies. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39863.
In situ small angle X‐ray scattering study on structural evolution of crosslinked polytetrafluoroethylene during deformation
Authors: Li Xiaoyun , Tian Feng , Yang Chunming , Tang Zhongfeng , Miao Xiaran , Wu Guozhong , Li Xiuhong , Wang Jie , Li Liangbin
Published: October 2013

The structural evolution of virgin and crosslinked polytetrafluoroethylene (PTFE) during stretching was studied by in situ synchrotron small‐angle X‐ray scattering (SAXS). Both yield and tensile stress of crosslinked PTFE increased with increasing crosslinking density. During stretching, for virgin PTFE, amorphous chains gradually turned to tensile direction at early stage, perpendicularly arranged lamellar stacks appeared at high strains (>140%). While for crosslinked PTFE, lamellar structure was observed even at lower strains; with increasing irradiation dose, the lamellar structure became obvious and the long period decreased. Four‐point SAXS patterns were observed only in 3000kGy‐dosed PTFE during deformation, which indicated that an alternately tilted lamella arrangement called herringbone structure was formed. Radiation dose induces crosslinked networks formed, which can carry part of local stress during deformation, resulting in the increase of yield and tensile stress. Crosslinking density is an important factor on structural evolution. In addition, a deformation mechanism of different crosslinked PTFE is proposed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39883.
PMMA composites of single‐walled carbon nanotubes‐graft‐PMMA
Authors: Paul Abhijit , Grady Brian P. , Ford Warren T.
Published: October 2013

To facilitate the dispersion of single‐walled carbon nanotubes (SWCNT) into poly(methyl methacrylate) (PMMA), SWCNT were functionalized with a RAFT chain transfer agent, and PMMA was grafted from the SWCNT by reversible addition–fragmentation transfer (RAFT) polymerization to give SWCNT‐g‐PMMA containing 6 wt % PMMA. SWCNT‐g‐PMMA in the form of small bundles was dispersed into PMMA matrices. The SWCNT‐g‐PMMA filler increased the glass transition temperature (Tg) of the composite when the matrix molecular weight Mn was less than the graft molecular weight, but not when the matrix Mn was equal to or greater than the graft Mn. The threshold of electrical conductivity of the composites as a function of weight percent SWCNT increased from 0.2% when matrix Mn was less than graft Mn to about 1% when matrix Mn was greater than graft Mn. Dynamic mechanical analyses of the composites having graft Mn less than or equal to matrix Mn showed broader rubbery plateaus with increased SWCNT content but no significant differences between samples with different grafted PMMAs. The results indicate that lower Mn matrix wets the SWCNT‐g‐PMMA whereas higher Mn matrix does not wet the SWCNT‐g‐PMMA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39884.
Tailoring adhesive forces between poly(dimethylsiloxane) and glass substrates using poly(vinyl alcohol) primers
Authors: Emoto Akira , Kobayashi Tomoko , Noguchi Naomi , Fukuda Takashi
Published: October 2013

A thin poly(vinyl alcohol) (PVA) layer has been found to control adhesive forces between poly(dimethylsiloxane) (PDMS) and a glass substrate. Various PVAs were coated on glass substrates on top of which PDMS pre‐polymer was cast. After thermal curing, the peel strength was tested. It was found that the fundamental adhesive forces are attributed to the degree of hydrolysis (or saponification value) of the PVAs. For a PVA modified with a silanol group, strong adhesive force resulted. The range of tailoring the force with the PVAs was 16 kgf/m. The production of thin interlaminated PVA layers as primers was demonstrated. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39927.
Phenolic foams modified by cardanol through bisphenol modification
Authors: Jing Shuailin , Li Tao , Li Xiaojuan , Xu Qian , Hu Jing , Li Ruihai
Published: October 2013

In this study, cardanol, a natural phenol, has been applied to toughen phenolic foam by bisphenol modification. In order to verify the occurrence of Friedel–Craft alkylation between cardanol and phenol on the side chain, FTIR, and NMR had been used to characterize the bisphenol successfully. With the introduction of cardanol, the viscosity of prepolymers increased. The SEM results demonstrated that the some cells with increasingly large size existed, when the dosage of cardanol increased. With respect to the mechanical properties, phenolic foams modified by 10 wt % cardanol increased by 22% in flexural strength and 28% in bending modulus compared to pure phenolic foams, which indicates that the incorporation of cardanol does improve the toughness of phenolic foams. In addition, the effects of different dosage of cardanol on the apparent density and thermal stability of phenolic foams were investigated. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 39942.
Synthesis and characterization of nanoclay–polymer composites from soil clay with respect to their water‐holding capacities and nutrient‐release behavior
Authors: Sarkar Subhas , Datta Samar Chandra , Biswas Dipak Ranjan
Published: October 2013

Water and nutrients are two important inputs to agriculture that need to be used judiciously with higher efficiency to save these limited resources. For these purposes, a series of nanoclay–polymer composite (NCPC) superabsorbent nutrient carriers were prepared. These NCPCs were based on the reactions of different types of nanoclays (10 wt %) with partially neutralized acrylic acid and acryl amide by a free‐radical aqueous solution copolymerization reaction with N,N′‐methylene bisacrylamide as a crosslinker and ammonium persulfate as an initiator. The nanoclays isolated from three different types of soils were dominant in kaolinite (clay I), mica (clay II), and montmorillonite (clay III), and a portion of each was freed from amorphous aluminosilicate. Thus, there were six different types of nanoclays used, namely, those dominated by kaolinite, mica, and smectite with and without amorphous aluminosilicate. Fourier transform infrared spectroscopy and X‐ray diffraction (XRD) investigations showed evidence of interaction between the clays and polymer. XRD investigation also showed that the reaction between the polymer and clays I and II occurred on the surface of various clay particles without intercalating into the stacked silicate galleries, whereas in the case of clay III (the smectite‐dominated clay), evidence indicated the intercalation of polymer into the stacked silicate galleries of the clay and the exfoliation of the clay. The water absorbency decreased in the NCPCs compared to that of the pure polymeric hydrogel. In case of the pure polymer, the entire amount of nutrient loading released within 15 h of incubation; this was higher than that of the NCPCs. In the initial stage (up to 15 h), no significant differences in nutrient release were observed among the different polymer/clay composites, but there were differences in later stages. Among the different NCPCs, the percentage release of nutrients at 48 h ranged from around 70% in the polymer/clay III composite to 90% in the polymer/clay I composite. The presence of amorphous aluminosilicates in clay did not make any difference in the nutrient‐release rate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39951.
Low temperature curable epoxy siloxane hybrid materials for LED encapsulant
Authors: Kim HweaYoon , Bae Jun‐young , Kim Yong Ho , Kim Yu Bae , Bae Byeong‐Soo
Published: October 2013

A thermally cured epoxy‐siloxane hybrid material that is curable at low temperature (L‐expoxy hybrimer) was investigated for use as an LED encapsulant. This new hybrimer was fabricated using thermally initiated, cationic polymerization of cycloaliphatic epoxy oligosiloxane (CAEO) resin, derived from non‐hydrolytic sol–gel, mixed with oxetane hardener in the presence of a hexafluoroantimonate‐type thermo‐cationic initiator. The L‐epoxy hybrimer was cured at a lower temperature (below 120°C) than previously reported for an epoxy hybrimer with anhydride hardener (above 180°C). The L‐epoxy hybrimer showed high thermal resistance to yellowing under long‐term high temperature condition, and maintained good optical transmittance. Also, it had a high refractive index (up to 1.57), as well as the hardness (Shore D 80), and low water‐vapor permeability, when the new hybrimer was used to encapsulate an LED, it showed good adhesion without cracks or delamination and maintained their initial performance after the long‐term aging tests (120 and 85°C at 85% humidity). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39968.
Copper phthalocyanine oligomer grafted acrylic elastomer nanocomposites with high dielectric constants
Authors: Liu Ruonan , Wang Jingwen , Li Qing , Li Shuqin , Zhang Su , Ding Xuejiao
Published: October 2013

For many applications of dielectric elastomer (DE) actuators, it is desirable to endow the DE with a high dielectric constant (ε), high breakdown field, and good flexibility. In this study, a high‐ε nanocomposite acrylic elastomer (ACM)‐g‐copper phthalocyanine (CuPc) was fabricated, in which the CuPc oligomer was grafted onto the backbone of ACM. This grafted composite exhibited several benefits over the physically blended one. Transmission electron microscopy micrographs indicated that the size of the grafted CuPc was in the range 15–30 nm, which was more than 25 times smaller than that of the simply blended one. At room temperature, ε of ACM‐g‐CuPc (with 15 wt % CuPc) reached 303 at 100 Hz. The remarkable enhancement in the dielectric response could be attributed to the greatly strengthened exchange coupling effect and the Maxwell–Wagner–Sillars polarization mechanism. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39975.
Structural and functional changes of silk fibroin scaffold due to hydrolytic degradation
Authors: Farokhi Mehdi , Mottaghitalab Fatemeh , Hadjati Jamshid , Omidvar Ramin , Majidi Mohammad , Amanzadeh Amir , Azami Mahmoud , Tavangar Seyed Mohammad , Shokrgozar Mohammad Ali , Ai Jafar
Published: October 2013

In this study, hydrolytic degradation of silk fibroin (SF) in Phosphate buffer saline (PBS) after 12 weeks incubation was investigated. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X‐ray diffraction (XRD) patterns have confirmed the transition from crystalline β‐sheet to random coil in treated SF. A decrease in adhesion force and surface Young's modulus were observed using atomic force microscopy (AFM). Structural changes were further confirmed using scanning electron microscopy (SEM). Biocompatibility and alkaline phosphatase production of osteoblast cells were decreased significantly in treated SF scaffold. Moreover, a significant decrease in mRNA level of collagen type I and osteopontin compared with fresh SF scaffold was observed. Finally, structural and biological characteristics of SF scaffold could alter in PBS. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39980.
Reflections on Energy Security in the Asia Pacific
Authors: Cronshaw Ian , Grafton Quentin
Published: October 2013

This article reviews key past trends in energy security from the perspective of both International Energy Agency members and the Asia Pacific over the past 30 years, and assesses future energy risks. Developments in energy efficiency, unconventional oil and gas, and stationary renewable energy sources are highlighted. Lessons learned from past policy successes and failures provide the basis for 10 reflections to promote energy security in the region.
A modelling study of the role of marine protected areas in metapopulation genetic connectivity in Delaware Bay oysters
Authors: Munroe Daphne M. , Klinck John M. , Hofmann Eileen E. , Powell Eric N.
Published: October 2013

Management decisions concerning location and extent of marine protected areas (MPAs) both for exploited and unexploited resources rely on understanding how populations are interconnected.

The potential effects of MPA location and external fishing pressure on genetic connectivity of eastern oyster (Crassostrea virginica) populations in Delaware Bay were examined.

An individual‐based metapopulation model that includes post‐settlement population dynamics, larval dispersal, and genetic structure was used to simulate four oyster populations for two periods (1970s and 2000s) with distinct population and environmental conditions. Sensitivity analysis examined the influence of larval dispersal, and simulations included combinations of MPA location (which population was protected) and three fishing mortality rates for non‐MPA populations: low (4%), medium (8%) and high (30%); no fishing was allowed in the MPAs.

Results showed (i) salinity‐driven changes in larval dispersal led to relatively small, population‐specific connectivity changes, (ii) MPAs can enhance the frequency of genotypes originating within protected populations in unprotected populations when fishing rates are high (30%), and (iii) demographic shifts can impose temporal variability on the influence of MPAs on connectivity.

These results suggest that genetic consequences of siting MPAs must be considered in terms of present population and environmental conditions, as well as allowing for changes in population and genetic connectivity that may shift fundamentally over time.

Simulation results indicate that siting protected areas for oyster restoration in low salinity (<12ppt) regions may interact with development of disease resistance in the metapopulation by altering genotype transfer from protected to unprotected downestuary populations.

Copyright © 2013 John Wiley & Sons, Ltd.
EFFECT OF STARVATION ON LIPOPHORIN DENSITY IN FIFTH INSTAR LARVAL Manduca sexta
Authors: Gondim Katia C. , Pennington James E. , Meyer‐Fernandes José Roberto , Alves‐Bezerra Michele , Wells Michael A.
Published: October 2013

Lipophorin (Lp) is a major insect lipoprotein and is responsible for lipid transport between organs. In this study, the effect of starvation on Lp properties was analyzed in larval Manduca sexta during the fifth instar. Lp hemolymph concentrations in larvae at days 1 and 2 were around 2–3 mg/ml and at day 3 it increased to 8 mg/ml. When larvae were starved for 24 h, they did not grow, but their body mass and hemolymph volume did not decrease significantly. Differences in Lp densities were observed. In fed larvae, from days 1 to 4, two major Lp populations were found with densities of 1.124 ± 0.002 (high density Lp‐larval1, HDLp‐L1) and 1.141 ± 0.002 g/ml (HDLp‐L2). When larvae were starved for 24 h, only one Lp population was present, with density 1.114 ± 0.001 g/ml (HDLp‐Ls). When larvae were abdominally ligated at day 1 or 2 of fifth instar, only HDLp‐Ls was found after 24 h, indicating that the formation of this HDLp population was not dependent on any factor released by head. On the other hand, larvae that were ligated at day 3 showed the same Lp populations as the fed ones. In 24‐h starved larvae, lipid load in Lp was higher as compared to the fed controls. In 24‐h ligated larvae Lp lipid content increased when ligation was performed on day 1 or 2, but not on day 3. So, different responses to starvation can be observed depending on the developmental phase of the same larval instar.
Brief Report: Carboxypeptidase B Serves as a Protective Mediator in Osteoarthritis
Authors: Lepus Christin M. , Song Jason J. , Wang Qian , Wagner Catriona A. , Lindstrom Tamsin M. , Chu Constance R. , Sokolove Jeremy , Leung Lawrence L. , Robinson William H.
Published: October 2013

Objective

We previously demonstrated that carboxypeptidase B (CPB) protects against joint erosion in rheumatoid arthritis by inactivating complement component C5a. We also found that levels of CPB are abnormally high in the synovial fluid of individuals with another joint disease, osteoarthritis (OA). We undertook this study to investigate whether CPB plays a role in the pathogenesis of OA.

Methods

We compared the development of OA in CPB‐deficient (Cpb2–/–) mice and wild‐type mice by subjecting them to medial meniscectomy and histologically assessing cartilage damage, osteophyte formation, and synovitis in the stifle joints 4 months later. We measured levels of proCPB, proinflammatory cytokines, and complement components in synovial fluid samples from patients with symptomatic and radiographic knee OA. Finally, we used enzyme‐linked immunosorbent assay, flow cytometry, and hemolytic assays to assess the effect of CPB on formation of membrane attack complex (MAC)–a complement effector critical to OA pathogenesis.

Results

Cpb2–/– mice developed dramatically greater cartilage damage than did wild‐type mice (P < 0.01) and had a greater number of osteophytes (P < 0.05) and a greater degree of synovitis (P < 0.05). In synovial fluid samples from OA patients, high levels of proCPB were associated with high levels of proinflammatory cytokines and complement components, and levels of proCPB correlated positively with those of MAC. In in vitro complement activation assays, activated CPB suppressed the formation of MAC as well as MAC‐induced hemolysis.

Conclusion

Our data suggest that CPB protects against inflammatory destruction of the joints in OA, at least in part by inhibiting complement activation.
Demonstrating conceptual dynamics in an evolving text collection
Authors: Darányi Sándor , Wittek Peter
Published: October 2013

Based on real‐world user demands, we demonstrate how animated visualization of evolving text corpora displays the underlying dynamics of semantic content. To interpret the results, one needs a dynamic theory of word meaning. We suggest that conceptual dynamics as the interaction between kinds of intellectual and emotional content and language is key for such a theory. We demonstrate our method by two‐way seriation, which is a popular technique to analyze groups of similar instances and their features as well as the connections between the groups themselves. The two‐way seriated data may be visualized as a two‐dimensional heat map or as a three‐dimensional landscape in which color codes or height correspond to the values in the matrix. In this article, we focus on two‐way seriation of sparse data in the Reuters‐21568 test collection. To achieve a meaningful visualization, we introduce a compactly supported convolution kernel similar to filter kernels used in image reconstruction and geostatistics. This filter populates the high‐dimensional sparse space with values that interpolate nearby elements and provides insight into the clustering structure. We also extend two‐way seriation to deal with online updates of both the row and column spaces and, combined with the convolution kernel, demonstrate a three‐dimensional visualization of dynamics.
Subject matter categorization of tags applied to digital images from art museums
Authors: Klavans Judith L. , LaPlante Rebecca , Golbeck Jennifer
Published: October 2013

In recent years, cultural heritage institutions have increasingly used social tagging. To better understand the nature of these tags, we analyzed tags assigned to a collection of 100 images of art (provided by the steve.museum project) using subject matter categorization. Our results show that the majority of tags describe the people and objects in the image and are generic in nature. This contradicts prior subject matter analyses of queries, tags, and index terms of other image collections, suggesting that the nature of social tags largely depends on the type of collection and on user needs. This insight may help cultural heritage institutions improve their management and use of tags.
Searching for specific health‐related information in MedlinePlus: Behavioral patterns and user experience
Authors: Zhang Yan
Published: October 2013

Searches for specific factual health information constitute a significant part of consumer health information requests, but little is known about how users search for such information. This study attempts to fill this gap by observing users' behavior while using MedlinePlus to search for specific health information. Nineteen students participated in the study, and each performed 12 specific tasks. During the search process, they submitted short queries or complete questions, and they examined less than 1 result per search. Participants rarely reformulated queries; when they did, they tended to make a query more specific or more general, or iterate in different ways. Participants also browsed, primarily relying on the alphabetical list and the anatomical classification, to navigate to specific health topics. Participants overall had a positive experience with MedlinePlus, and the experience was significantly correlated with task difficulty and participants' spatial abilities. The results suggest that, to better support specific item search in the health domain, systems could provide a more “natural” interface to encourage users to ask questions; effective conceptual hierarchies could be implemented to help users reformulate queries; and the search results page should be reconceptualized as a place for accessing answers rather than documents. Moreover, multiple schemas should be provided to help users navigate to a health topic. The results also suggest that users' experience with information systems in general and health‐related systems in particular should be evaluated in relation to contextual factors, such as task features and individual differences.