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Topologically associating domain (TAD) boundaries are the flanking edges of TADs, also known as insulated neighborhoods, within the 3D structure of genomes. A prominent feature of TAD boundaries in mammalian genomes is the enrichment of clustered CTCF sites often with mixed orientations, which can either block or facilitate enhancer–promoter (E‐P) interactions within or across distinct TADs, respectively. We will discuss recent progress in the understanding of fundamental organizing principles of the clustered CTCF insulator codes at TAD boundaries. Specifically, both inward‐ and outward‐oriented CTCF sites function as topological chromatin insulators by asymmetrically blocking improper TAD‐boundary‐crossing cohesin loop extrusion. In addition, boundary stacking and enhancer clustering facilitate long‐distance E‐P interactions across multiple TADs. Finally, we provide a unified mechanism for RNA‐mediated TAD boundary function via R‐loop formation for both insulation and facilitation. This mechanism of TAD boundary formation and insulation has interesting implications not only on how the 3D genome folds in the Euclidean nuclear space but also on how the specificity of E‐P interactions is developmentally regulated. [ABSTRACT FROM AUTHOR]

The transcriptome data of skin cells from domestic cats with brown, orange, and white coats were analyzed using a public database to investigate the possible relationship between coat color‐related gene expression and squamous cell carcinoma risk, as well as the mechanism of deafness in white cats. We found that the ratio of the expression level of genes suppressing squamous cell carcinoma to that of genes promoting squamous cell carcinoma might be considerably lower than the theoretical estimation in skin cells with orange and white coats in white‐spotted cat. We also found the possibility of the frequent production of KIT lacking the first exon (d1KIT) in skin cells with white coats, and d1KIT production exhibited a substantial negative correlation with the expression of SOX10, which is essential for melanocyte formation and adjustment of hearing function. Additionally, the production of d1KIT was expected to be due to the insulating activity of the feline endogenous retrovirus 1 (FERV1) LTR in the first intron of KIT by its CTCF binding sequence repeat. These results contribute to basic veterinary research to understand the relationship between cat skin coat and disease risk, as well as the underlying mechanism. [ABSTRACT FROM AUTHOR]

Excessive exposure to ultraviolet (UV) and high‐energy visible (HEV) light can cause sunburns, wrinkles, and even skin cancer. Therefore, the development of effective UV–HEV‐shielding agents is of great importance to human health. In this study, semiconducting graphitic carbon nitride (g‐C3N4) is incorporated into the interlayer space of mica through the intercalation of cyanamide and subsequent pyrolysis reactions to form a semiconductor–insulator nanohybrid, namely g‐C3N4–mica, with a 1:1 heterostructure. The g‐C3N4–mica nanohybrid exhibits excellent UV–HEV absorption properties below 450 nm, and its photocatalytic activity is quenched owing to the effective screening of photocatalytic active sites by the insulating mica. It is strongly believed that the proposed g‐C3N4–mica nanohybrid can be applied as a UV–HEV blocking agent owing to its excellent UV–HEV (200–450 nm)‐screening property without any photocatalytic effect or phototoxicity. [ABSTRACT FROM AUTHOR]

The cohesin complex has a range of crucial functions in the cell. Cohesin is essential for mediating chromatid cohesion during mitosis, for repair of double‐strand DNA breaks, and for control of gene transcription. This last function has been the subject of intense research ever since the discovery of cohesin's role in the long‐range regulation of the cut gene in Drosophila. Subsequent research showed that the expression of some genes is exquisitely sensitive to cohesin depletion, while others remain relatively unperturbed. Sensitivity to cohesin depletion is also remarkably cell type‐ and/or condition‐specific. The relatively recent discovery that cohesin is integral to forming chromatin loops via loop extrusion should explain much of cohesin's gene regulatory properties, but surprisingly, loop extrusion has failed to identify a 'one size fits all' mechanism for how cohesin controls gene expression. This review will illustrate how early examples of cohesin‐dependent gene expression integrate with later work on cohesin's role in genome organization to explain mechanisms by which cohesin regulates gene expression. [ABSTRACT FROM AUTHOR]

The large band gap insulator LiCaAlF6 (LiCAF) has been proposed as a possible host crystal for future realizations of a solid‐state based thorium‐229 nuclear clock, due to its excellent optical transmission in the vacuum ultraviolet range. To enable direct optical manipulation of the thorium isomeric state, the band gap has to remain larger than the nuclear excitation energy upon crystal doping. Here, a systematic search for possible charge compensation mechanisms, defect locations, and the emergence of other compounds, using density functional theory, is presented. Out of 535 optimized structures, the energetically most favorable arrangement is ThAl•+VLi′${\mathrm{Th}}_{\mathrm{Al}}^{\bullet}+{\mathrm{V}}_{\mathrm{Li}}^{\prime}$ with an estimated band gap of 11.4 eV. Evaluating relevant uncertainties of the used methods suggests that the doped material remains transparent at the 229Th isomer energy for all investigated configurations. [ABSTRACT FROM AUTHOR]

CCCTC‐binding factor (CTCF) is an eleven zinc finger (ZF), multivalent transcriptional regulator, that recognizes numerous motifs thanks to the deployment of distinct combinations of its ZFs. The great majority of the ~50,000 genomic locations bound by the CTCF protein in a given cell type is intergenic, and a fraction of these sites overlaps with transcriptional enhancers. Furthermore, a proportion of the regions bound by CTCF intersect genes and promoters. This suggests multiple ways in which CTCF may impact gene expression. At promoters, CTCF can directly affect transcription. At more distal sites, CTCF may orchestrate interactions between regulatory elements and help separate eu‐ and heterochromatic areas in the genome, exerting a chromatin barrier function. In this review, we outline how CTCF contributes to the regulation of the three‐dimensional structure of chromatin and the formation of chromatin domains. We discuss how CTCF binding and architectural functions are regulated. We examine the literature implicating CTCF in controlling gene expression in development and disease both by acting as an insulator and a factor facilitating regulatory elements to efficiently interact with each other in the nuclear space. [ABSTRACT FROM AUTHOR]

Herein, the deposition of homogeneous ZrxHf(1−x)O2 (x < 1) thin films for dynamic random‐access memory (DRAM) capacitor dielectric layers by atomic layer deposition (ALD) using a mixed precursor mixture of two precursors is investigated. ZrO2‐ and HfO2‐based thin films are widely used as capacitor dielectric layers because of their high dielectric constant (k) values and low leakage current properties. Herein, particularly, films with mixed structures of ZrO2/HfO2 are investigated because ZrO2 supports the growth of HfO2 in the tetragonal phase. However, the mixed structures deposited by ALD remain inhomogeneous even after the annealing process. The inhomogeneity results in part of the HfO2 remaining in the monoclinic phase, which reduces the k value. Herein, the formation of homogeneous tetragonal‐phase ZrxHf1−xO2 using a mixed precursor consisting of CpZr and CpHf precursors is investigated. The formation of the tetragonal phase in the ZrxHf(1−x)O2 thin films is determined through chemical and structural analysis. The variation of the electrical properties with the Zr/Hf concentration ratio is investigated. The electrical properties are enhanced compared to laminated ZrO2/HfO2 and single thin films. [ABSTRACT FROM AUTHOR]

In general, cathode triple junctions (CTJ) are regarded as electrical weakness points because of the occurrence of electron emission. It's believed that vacuum surface flashover starts from the initiation of electron emission at CTJ. Therefore, it is important to investigate electron emission phenomenon around the CTJ region. However, such a study which is direct measurement of the electron emission from CTJ has not been almost done because it is difficult to measure it directly. So, the purpose of this study is to elucidate the electron emission phenomenon from CTJ by investigating field electron emission current characteristics and charge distribution at CTJ region. Thus, we measured the electron emission current and the surface potential for the samples which CTJ was formed artificially. In addition, we simulated the electric lines of force near CTJ region. The results show that electron emission current increases due to the effect of the insulator surface being charged by the electrons emitted from the CTJ. [ABSTRACT FROM AUTHOR]

A method is needed to prevent damage of wind power generators from lightning strikes even if lightning strikes the blades. In our experiment, the discharge progressing to the film was hard to penetrate the low surface resistivity polyethylene terephthalate (PET) films with conductive coating on one side, although the discharge always penetrated the uncoated PET film. This result was confirmed when the coated surface of the film was directed to either the high voltage rod electrode side or the ground plate electrode side. It was also confirmed that the progress of negative leader generated from the high voltage rod electrode side was hindered by the film from the photograph with the high speed camera. The time constant was calculated from the product of the surface resistance and the capacitance between the film and the plate electrode. As a result, itwas suggested that the propagation of electric potential might be fast because time constant is smaller in the case of the low surface resistivity PET films. [ABSTRACT FROM AUTHOR]

Tyr is the mouse gene that encodes tyrosinase, an enzyme that triggers the first and rate‐limiting step in the biosynthesis of melanin. Mutations in Tyr might result in non‐functional Tyr protein and, consequently, loss of pigment production. This is a rare genetic condition, known as albinism, described for most animal species and one of the most obvious and simple phenotypes to investigate in model organisms. Mutations in the orthologous human TYR gene are associated with oculocutaneous albinism type 1 (OCA1). Over the last thirty years, the mouse Tyr locus has been studied as a paradigm for how genes and expression domains are organized and regulated in mammalian genomes. This review summarizes the major findings and experimental strategies used, from the production of conventional transgenic mice to the latest CRISPR‐Cas9 genome‐edited animals. The main conclusion inferred from all of these studies, which extends beyond the analysis of the mouse Tyr locus, is the relevance of analyzing non‐coding regulatory DNA elements in their natural chromosomal environment, and not only as randomly inserted transgenes. Further, the identification of evolutionary conserved regulatory sequences might highlight new vulnerable sites in the human TYR gene, whose mutations could also be associated with albinism. [ABSTRACT FROM AUTHOR]

Synthetic biology circuits are often constructed with multiple gene expression units assembled in close proximity, and they can be used to perform complex functions in embryonic stem cells (ESCs). However, mutual interference between transcriptional units has not been well studied in mouse ESCs. To assess the efficiency of insulators at suppressing promoter interference in mouse ESCs, we used an evaluation scheme in which a tunable tetracycline response element promoter is connected to a constant Nanog promoter. The chicken hypersensitive site 4 (cHS4) insulator, widely used both for enhancer blocking and for barrier insulation in vitro and in vivo, was positioned between the two expression units for assessment. By inserting the cassette into various loci of the mouse ESC genome with PiggyBac transposon, we were able to quantitatively examine the protective effect of cHS4 by gradually increasing the transcriptional activity of the tetracycline response element promoter with doxycycline and then measuring the transcriptional activity of the Nanog promoter. Our results indicate that the cHS4 insulator has minimal insulating effects on promoter interference in mouse ESCs. Further studies show that the cHS4 insulation effect may be promoter specific and related to interaction with CCCTC‐binding factor‐mediated loop formation. In addition, we also compared DNA transposition and transgene expression with or without the cHS4 insulator using well‐established ESC reporters. The results indicate that cHS4 has no apparent effects on DNA transposition and transgene expression levels, but exerts modest protective effects on long‐term transgene silencing. [ABSTRACT FROM AUTHOR]

The crystal structure, Hirshfeld surface analysis and spectroscopic analysis of a new polyoxometalate (POM) compound, namely, nonakis(2‐methoxyaniline) bis(diphosphopentamolybdate) trihydrate, (C7H9NO)9[P2Mo5O23]2·3H2O, is reported. The title compound was synthesized using the solution method and was structurally characterized by single‐crystal X‐ray diffraction, which revealed P symmetry. A study of the intermolecular interactions using Hirshfeld surface analysis confirmed that the hydrogen‐bonding interactions play the dominant role in the stability of the crystal structure. The refinement was complicated by extensive disorder affecting 11 of the 16 ions and molecules in the asymmetric unit. IR and UV–Vis spectroscopic techniques were used to identify the vibrational modes and to classify this compound as an insulator. [ABSTRACT FROM AUTHOR]

Round‐robin exercises on three‐ and four‐point flexural tests were successfully conducted to evaluate the fracture strength of Si3N4, Al2O3, and AlN thin plates for power modules. A 0.64 mm × 12 mm × 40 mm test specimen was loaded in three‐point flexure with a major span of 30 mm or was loaded in four‐point flexure with a major/minor span of 30/10 mm. For a 0.32 mm × 12 mm × 20 mm test specimen, both major and minor spans were halved. All test specimens were loaded in a fully articulated fixture provided by the test organizer. Reasonable consistencies in the resultant flexural strength were obtained between laboratories, indicating our new test condition for three‐ and four‐point bending of thin ceramic plates is satisfactory for reliable measurement of the flexural strength. [ABSTRACT FROM AUTHOR]

The porcelain ceramic insulators have been used for outdoor insulation applications for a long time due to their impressive electrical and mechanical properties. The lightning impulse withstand voltage and flashover voltage characteristics of the insulators are important for insulation coordination of transmission lines and substations. This study presents a computer‐based simulation methodology to determine the positive polarity lighting impulse flashover voltage of porcelain suspension and station post‐insulators. The flashover voltage is determined by evaluating the streamer inception, propagation and sustenance criteria along the suitable paths based on finite‐element‐method‐based electric field computation. The streamer propagation path is found through air along the dry arcing distance rather than along the creepage path of the insulator. The lightning impulse flashover voltage of suspension and post‐insulators are computed based on simulation. The comparison of computed results with the experimental results gives a good agreement between them. [ABSTRACT FROM AUTHOR]

SUMMARY The radiation field from the spark discharge on faulty insulators of distribution lines often influences broadcasting services of radio and television, and communication services. The spark discharge occurs due to loose connection in a metal-fittings connection of strain insulators. The rust of metal-fittings and the low-tension of wire are causes of loose connection. In this paper, the generation conditions of spark discharge were clarified by the basic experiment. And the radiation field which includes frequency component of several GHz due to the spark discharge was measured using a 6.6 kV full-scale distribution line, and the amplitude probability distribution of electric field was analyzed. [ABSTRACT FROM AUTHOR]

ABSTRACT In the present work, a metamaterial-based insulator is proposed as a mean to achieve both highly compact and loosely coupled array of antennas. Its main working principle is summarized through a general qualitative analysis. The theoretical results are supported by experimental evidences. The chosen operating frequency is 2.4 GHz considering that it is a usual frequency for many indoor wireless applications. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1420-1423, 2017 [ABSTRACT FROM AUTHOR]

Abstract: Recent years have witnessed an increase in attention to the direct synthesis of graphene on a variety of insulators by virtue of chemical vapor deposition (CVD), which has shown great potential in a broad range of applications. In this Focus Review, we summarize the key research efforts on the development of CVD routes to allow direct deposition of graphene on insulating materials, with a special focus upon our recent progress towards graphene synthesis employing hexagonal boron nitride, glass, and SrTiO3 planar substrates, as well as NaCl powders. To begin with, we outline the important features and necessities in the field of graphene synthesis by direct CVD. We then provide an up‐to‐date research summary with respect to the employment of substrate (planar vs. powder; novel vs. conventional), the design of synthetic methods, and the quality/property control of products. Finally, we discuss the potential challenges and opportunities for the direct CVD growth of graphene on insulators. [ABSTRACT FROM AUTHOR]

Architectural proteins mediate interactions between distant sequences in the genome. Two well-characterized functions of architectural protein interactions include the tethering of enhancers to promoters and bringing together Polycomb-containing sites to facilitate silencing. The nature of which sequences interact genome-wide appears to be determined by the orientation of the architectural protein binding sites as well as the number and identity of architectural proteins present. Ultimately, long range chromatin interactions result in the formation of loops within the chromatin fiber. In this review, we discuss data suggesting that architectural proteins mediate long range chromatin interactions that both facilitate and hinder neighboring interactions, compartmentalizing the genome into regions of highly interacting chromatin domains. [ABSTRACT FROM AUTHOR]

In this work, we investigate the enhanced performance of amorphous indium zinc oxides-based thin film transistors with hafnium silicate (HfSiOx) gate insulators. HfSiOx gate insulators annealed at various conditions are deposited by cosputtering of hafnium oxide and Si. The structural properties of HfSiOx are investigated using the atomic force microscopy, X-ray diffraction, and x-ray photoelectron spectroscopy (XPS). techniques. Furthermore, the electrical characteristics of HfSiOx are analyzed to investigate the effect of annealing conditions. We obtain optimal results for thin film transistors with HfSiOx gate insulators annealed for 1 h at 100 °C, with a saturation mobility of 1.2 cm2/V · s, threshold voltage of 2.2 V, on current/off current ratio of 2.0 × 106, and an insulator surface roughness of 0.187 nm root mean square. [ABSTRACT FROM AUTHOR]

ABSTRACT New low-temperature curable organic/inorganic hybrid polymers were designed and synthesized as gate dielectrics for organic thin-film transistors (OTFTs). Allyl alcohols were introduced to polyhedral oligomeric silsesquioxane (POSS) via hydrosilyation to produce an alcohol-functionalized POSS derivative (POSS-OH). POSS-OH was then reacted with hexamethoxymethylmelamine at carrying molar ratios at 80 °C in the presence of a catalytic amount of p-toluenesulfonic acid to give highly cross-linked network polymers (POSS-MM). The prepared thin films were smooth and hard after the thermal cross-linking reaction and had very low leakage currents (<10−8 A/cm2) with no significant absorption over the visible spectral range. Pentacene-based OTFTs using the synthesized insulators as gate dielectric layers had higher hole mobilities (up to 0.36 cm2/Vs) than a device using thermally cross-linked poly(vinyl phenol) and melamine as the gate dielectric layer (0.18 cm2/Vs). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 3260-3268 [ABSTRACT FROM AUTHOR]

Dual-beam depth profiling strategy has been widely adopted in time-of-flight secondary ion mass spectrometry depth profiling, in which two basic operation modes, interlaced mode and non-interlaced mode, are commonly used. Generally, interlaced mode is recommended for conductive or semi-conductive samples, whereas non-interlaced mode is recommended for insulating samples, where charge compensation can be an issue. Recent publications, however, show that the interlaced mode can be used effectively for glass depth profiling, despite the fact that glass is an insulator. In this study, we provide a simple guide for choosing between interlaced mode and non-interlaced mode for insulator depth profiling. Two representative cases are presented: (i) depth profiling of a leached glass sample and (ii) depth profiling of a single-crystal MgO sample. In summary, the interlaced mode should be attempted first, because (i) it may provide data with reasonable quality, (ii) it is time-saving for most cases, and (iii) it introduces low H/C/O background. If data quality is the top priority and measurement time is flexible, non-interlaced mode is recommended because interlaced mode may suffer from low signal intensity and poor mass resolution. A big challenge is tracking trace H/C/O in a highly insulating sample (e.g., MgO), because non-interlaced mode may introduce strong H/C/O background, but interlaced mode may suffer from low signal intensity. Meanwhile, a C or Au coating is found to be very effective to improve the signal intensity. Surprisingly, the best analyzing location is not on the C or Au coating but at the edge (outside) of the coating. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Impulsive-disinhibited personality (IDP) is a behavioral trait mainly characterized by seeking immediate gratification at the expense of more enduring or long-term gains. This trait has a major role in the development of several disinhibitory behaviors and syndromes, including psychopathy, attention-deficit and hyperactivity disorder, cluster-B personality disorders, criminality and alcoholism. Available data consistently support a strong heritable component, accounting for 30-60% of the observed variance in personality traits. A genome-wide analysis of copy-number variants was designed to identify novel genetic pathways associated with the IDP trait, using a series of 261 male participants with maximized opposite IDP scores. Quantitative trait locus analysis of candidate copy-number variants (CNVs) was conducted across the entire IDP continuum. Functional effects of associated variants were evaluated in zebrafish embryos. A common CNV mapping to the immune-related gene SIRPB1 was significantly associated with IDP scores in a dose-dependent manner ( β = −0.172, P < 0.017). Expression quantitative trait locus analysis of the critical region revealed higher SIRPB1 mRNA levels associated with the haplotype containing the deleted allele ( P < 0.0007). Epigenetic marks highlighted the presence of two potential insulators within the deleted region, confirmed by functional assays in zebrafish embryos, which suggests that SIRPB1 expression rates are affected by the presence/absence of the insulator regions. Upregulation of SIRPB1 has been described in prefrontal cortex of patients with schizophrenia, providing a link between SIRPB1 and diseases involving disinhibition and failure to control impulsivity. We propose SIRPB1 as a novel candidate gene to account for phenotypic differences observed in the IDP trait. [ABSTRACT FROM AUTHOR]

Insulators are DNA-protein complexes that play a central role in chromatin organization and regulation of gene expression. In Drosophila different proteins, d CTCF, Su( Hw), and BEAF bind to specific subsets of insulators most of them having in common CP190. It has been shown that there are a number of CP190-binding sites that are not shared with any other known insulator protein, suggesting that other proteins could cooperate with CP190 to regulate insulator activity. Here we report on the identification of two previously uncharacterized proteins as CP190-interacting proteins, that we have named Ibf1 and Ibf2. These proteins localize at insulator bodies and associate with chromatin at CP190-binding sites throughout the genome. We also show that Ibf1 and Ibf2 are DNA-binding proteins that form hetero-oligomers that mediate CP190 binding to chromatin. Moreover, Ibf1 and Ibf2 are necessary for insulator activity in enhancer-blocking assays and Ibf2 null mutation cause a homeotic phenotype. Taken together our data reveal a novel pathway of CP190 recruitment to chromatin that is required for insulator activity. [ABSTRACT FROM AUTHOR]

ABSTRACT A new approach for preparing geological materials is proposed to reduce charging during their characterization in a scanning electron microscope. This technique was applied to a sample of the Nechalacho rare earth deposit, which contains a significant amount of the minerals fergusonite and zircon. Instead of covering the specimen surface with a conductive coating, the sample was immersed in a dilute solution of ionic liquid and then air dried prior to SEM analysis. Imaging at a wide range of accelerating voltages was then possible without evidence of charging when using the in-chamber secondary and backscattered electrons detectors, even at 1 kV. High resolution x-ray and electron backscatter diffraction mapping were successfully obtained at 20 and 5 kV with negligible image drifting and permitted the characterization of the microstructure of the zircon/fergusonite-Y aggregates encased in the matrix minerals. Because of the absence of a conductive layer at the surface of the specimen, the Kikuchi band contrast was improved and the backscatter electron signal increased at both 5 and 20 kV as confirmed by Monte Carlo modeling. These major developments led to an improvement of the spatial resolution and efficiency of the above characterization techniques applied to the rare earth ore and it is expected that they can be applied to other types of ores and minerals. Microsc. Res. Tech. 77:225-235, 2014. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Chromatin insulators are DNA protein complexes situated throughout the genome capable of demarcating independent transcriptional domains. Previous studies point to an important role for RNA in gypsy chromatin insulator function in Drosophila; however, the identity of these putative insulator-associated RNAs is not currently known. Here we utilize RNA-immunoprecipitation and high throughput sequencing (RIP-seq) to isolate RNAs stably associated with gypsy insulator complexes. Strikingly, these RNAs correspond to specific sense-strand, spliced and polyadenylated mRNAs, including two insulator protein transcripts. In order to assess the functional significance of these associated mRNAs independent of their coding function, we expressed untranslatable versions of these transcripts in developing flies and observed both alteration of insulator complex nuclear localization as well as improvement of enhancer-blocking activity. Together, these data suggest a novel, noncoding mechanism by which certain mRNAs contribute to chromatin insulator function. [ABSTRACT FROM AUTHOR]

The observation method of photoemission electron microscopy (PEEM) on insulating samples has been established in an extremely simple way. Surface conductivity is induced locally on an insulating surface by continuous radiation of soft X-rays, and Au films close to the area of interest allow the accumulated charges on the insulated area to be released to ground level. Magnetic domain observations of a NiZn ferrite, local X-ray absorption spectroscopy of sapphire, high-resolution imaging of a poorly conducting Li0.9CoO2 film surface, and Au pattern evaporation on a fine rock particle are demonstrated. Using this technique, all users' experiments on poorly conducting samples have been performed successfully at the PEEM experimental station of SPring-8. [ABSTRACT FROM AUTHOR]

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a congenital malformation that leads to severe pulmonary hypertension and respiratory failure. It has been associated with deletion of, or mutation in, FOXF1 on 16q24.1, a gene encoding a forkhead transcription factor expressed in the mesenchyme of the developing lung. Here we report on the identification of a pericentric inversion on chromosome 16 (p11.2q24.1) in a case of lethal ACDMPV with atrioventricular septal defect and duodenal atresia. Array-CGH indicated that the inversion is balanced, and FISH showed that the q-arm breakpoint occurs 134 ± 10 kb upstream (5′; centromeric) of FOXF1. This is suggestive of cis-regulatory elements located more than 130 kb 5′ of FOXF1, and analysis of genome-wide data sets of chromatin modifications in two different cell types suggested that the FOXF1 regulatory domain covers more than 300 kb, and perhaps up to 433 kb, upstream of the gene, but only 3 kb downstream. The 588 kb gene-free region between FOXF1 and the next gene in the centromeric direction, IRF8, is highly conserved between species and divided into two distinct regulatory domains by an insulator element. Another putative insulator occurs just downstream of FOXF1. Our results further strengthen the association between FOXF1 and a spectrum of malformations that include ACDMPV, atrioventricular septal defects, and gastrointestinal atresia. Furthermore, the presented analysis aids in defining the critical genomic region for this syndrome. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Realization of graphene devices is often hindered by the fact that the known layer growth methods do not meet the requirements of the device fabrication in silicon mainstream technology. For example, the relatively straightforward method of decomposition of hexagonal SiC is not CMOS-compatible due to the high-thermal budget it requires [Moon et al., IEEE Electron Device Lett. 31, 260 (2010)]. Techniques based on layer transfer are restricted because of the uncertainty of residual metal contaminants, particles, and structural defects. Of interest is thus a method that would allow one to grow a graphene film directly in the device area where graphene is needed. Production of large area graphene is not necessarily required in this case, but high quality of the film and metal-free growth on an insulating substrate at temperatures below 1000 °C are important requirements. We demonstrate direct growth of defect-free graphene on insulators at moderate temperatures by molecular beam epitaxy. The quality of the graphene was probed by high-resolution Raman spectroscopy, indicating a negligible density of defects. The spectra are compared with those from graphene flakes mechanically exfoliated from native graphite onto mica. These results are combined with insights from density functional theory calculations. A model of graphene growth on mica and similar substrates is proposed. [ABSTRACT FROM AUTHOR]

In high-voltage aerial distribution systems, the insulated cables are supported by the binding wire with the post insulator at the utility pole. When a lightning strike occurs in the neighborhood of the insulated cable in an aerial power distribution system, inductive lightning surges invade the central line of the cable. Then, creeping discharges develop along the cable surface from the binding wire tip at the same time as flashover of the post insulator at a supporting point of the cable. If the cable insulator has weak points such as pinholes, a malfunction near the cable supporting point may occur, with melting of the wire due to punch-through breakdown. To prevent such accidents, it is important to clarify the mechanism of the creeping discharge along the insulated cable caused by the lightning strike. The polarity of creeping discharges depends on the polarity of the inductive lightning surges, and the extension length and aspect of the discharge differ greatly depending on the discharge polarity. The development of these creeping discharges is attributed to complicated behavior of the positive and negative electric charges. In the present study, we examined in detail the development of a positive creeping discharge along a wire surface by using a high-speed image converter camera. This paper describes the mechanism of development of a positive creeping discharge based on the experimental results. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(3): 20–29, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20997 [ABSTRACT FROM AUTHOR]

Insulators bind transcription factors and use chromatin remodellers and modifiers to mediate insulation. In this report, we identified proteins required for the efficient formation and maintenance of a specialized chromatin structure at the yeast tRNA insulator. The histone acetylases, SAS-I and NuA4, functioned in insulation, independently of tRNA and did not participate in the formation of the hypersensitive site at the tRNA. In contrast, DNA polymerase ɛ, functioned with the chromatin remodeller, Rsc, and the histone acetylase, Rtt109, to generate a histone-depleted region at the tRNA insulator. Rsc and Rtt109 were required for efficient binding of TFIIIB to the tRNA insulator, and the bound transcription factor and Rtt109 in turn were required for the binding of Rsc to tRNA. Robust insulation during growth and cell division involves the formation of a hypersensitive site at the insulator during chromatin maturation together with competition between acetylases and deacetylases. [ABSTRACT FROM AUTHOR]

We have developed a novel evaluation technique of the deterioration degree of insulators for breakers using a chemical analysis and the Mahalanobis–Taguchi (MT) method. It is possible to evaluate the deterioration degree with great accuracy and nondestructively on-site by this technique without the effect of humidity and external noise such as electromagnetic waves. The mechanism of the insulator's surface resistivity reduction was clarified, and it was found that the deterioration degree of insulators could be evaluated by this technique because a linear relationship existed between the results judged by the MT method and the actual measurement results for the surface resistivity. In comparison to electrical methods, such as partial electric discharge and megohmmeters, the evaluation accuracy has been improved by three digits and the range of the deterioration degree that could be evaluated was expanded by seven digits. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(1): 11–20, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20849 [ABSTRACT FROM AUTHOR]

This paper describes a method for calculation of the effective relative dielectric constant ℇs of VVF cable. For power line communications (PLC), VVF cables in homes are used as 2- to 30-MHz high-frequency transmission media. As they are not designed and installed for such transmission media, there are many branches and impedance mismatch points that cause PLC signal reflections and standing waves. In order to estimate such standing wave generation and estimate undesirable PLC signal radio wave leakage, the length of the cable and the relative dielectric constant ℇs are important. However, the insulator of VVF cable is thin and not symmetric, so that it is not easy to calculate effective ℇs analytically. In this paper, the effective ℇs is calculated numerically using the PC software EXCEL by drawing the electrical fluxes and analyzing the effect of the insulator for each flux. The calculation result for VVF cable considering the limited insulator area around the conductors shows that the effective ℇs is about 13% less and the transmission speed is 7% faster than when the insulator occupies the full space around the cable. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(4): 24–31, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20862 [ABSTRACT FROM AUTHOR]

Long-range regulatory elements and higher-order chromatin structure coordinate the expression of multiple genes in cluster, and CTCF/cohesin-mediated chromatin insulator may be a key in this regulation. The human apolipoprotein (APO) A1/C3/A4/A5 gene region, whose alterations increase the risk of dyslipidemia and atherosclerosis, is partitioned at least by three CTCF-enriched sites and three cohesin protein RAD21-enriched sites (two overlap with the CTCF sites), resulting in the formation of two transcribed chromatin loops by interactions between insulators. The C3 enhancer and APOC3/A4/A5 promoters reside in the same loop, where the APOC3/A4 promoters are pointed towards the C3 enhancer, whereas the APOA1 promoter is present in the different loop. The depletion of either CTCF or RAD21 disrupts the chromatin loop structure, together with significant changes in the APO expression and the localization of transcription factor hepatocyte nuclear factor (HNF)-4α and transcriptionally active form of RNA polymerase II at the APO promoters. Thus, CTCF/cohesin-mediated insulators maintain the chromatin loop formation and the localization of transcriptional apparatus at the promoters, suggesting an essential role of chromatin insulation in controlling the expression of clustered genes. [ABSTRACT FROM AUTHOR]

Tomography in a focused ion beam (FIB) scanning electron microscope (SEM) is a powerful method for the characterization of three-dimensional micro- and nanostructures. Although this technique can be routinely applied to conducting materials, FIB–SEM tomography of many insulators, including biological, geological and ceramic samples, is often more difficult because of charging effects that disturb the serial sectioning using the ion beam or the imaging using the electron beam. Here, we show that automatic tomography of biological and geological samples can be achieved by serial sectioning with a focused ion beam and block-face imaging using low-kV backscattered electrons. In addition, a new ion milling geometry is used that reduces the effects of intensity gradients that are inherent in conventional geometry used for FIB–SEM tomography. [ABSTRACT FROM AUTHOR]

Cornelia de Lange syndrome (CdLS) is genetically heterogeneous and is usually sporadic, occurring approximately once per 10,000 births. CdLS individuals display diverse and variable deficits in growth, mental development, limbs, and organs. In the past few years it has been shown that CdLS is caused by gene mutations affecting proteins involved in sister chromatid cohesion. Studies in model organisms, and more recently in human cells, have revealed, somewhat unexpectedly, that the developmental deficits in CdLS likely arise from changes in gene expression. The mechanisms by which cohesion factors regulate gene expression remain to be elucidated, but current data suggest that they likely regulate transcription in multiple ways. [ABSTRACT FROM AUTHOR]

Abstract: To overcome positional and methylation effects on transgene expression, we developed a universal cloning cassette for in vivo assessment of regulatory elements using the luciferase reporter gene and the CCCD camera. Monitoring luciferase expression pattern in live mice enables screening of large numbers of transgenic founders quickly and inexpensively. We demonstrate that in the engineered transgenic mice, the chicken β-globin 5′HS4 insulator did not always provide the desirable expression pattern, and the Island Element, responsible for the demethylation of the surrounding DNA region, was not beneficial. Both tested liver-specific and developmentally regulated promoters exhibited the expected expression pattern in most transgenic founders. [Copyright &y& Elsevier]

Conidia from living conidiophores of barley powdery mildew ( Blumeria graminis f.sp. hordei) on host leaves were collected consecutively using an electrostatic spore collector. The collector consisted of an electrical conductor plate linked to an electrostatic voltage generator and insulator plates placed abreast on a timed conveyer. The conductor plate was negatively charged by the potential supplied from the voltage generator. The negatively charged conductor plate caused dielectric polarization of the insulator plate, and the surface charge on the insulator plate attracted mature conidia abstricted from conidiophores on colonies growing on leaves placed 2 cm from the insulator plate. The surface charge on the insulator plate was proportional to the voltage applied to the conductor plate. Under optimized conditions, abstricted conidia were attracted to the electrostatically activated insulator plates without any detriment to their survival. During a colony's life span of c. 460 h, conidia were released throughout the day and c. 12 × 104 conidia were collected during the lifetime of the colony. This is the first report on the direct quantification of progeny conidia produced by powdery mildew infecting host leaves. [ABSTRACT FROM AUTHOR]

Chromatin insulators have been implicated in the establishment of independent gene expression domains and in the nuclear organization of chromatin. Post-translational modification of proteins by Small Ubiquitin-like Modifier (SUMO) has been reported to regulate their activity and subnuclear localization. We present evidence suggesting that two protein components of the gypsy chromatin insulator of Dorsophila melanogaster, Mod(mdg4)2.2 and CP190, are sumoylated, and that SUMO is associated with a subset of genomic insulator sites. Disruption of the SUMO conjugation pathway improves the enhancer-blocking function of a partially active insulator, indicating that SUMO modification acts to regulate negatively the activity of the gypsy insulator. Sumoylation does not affect the ability of CP190 and Mod(mdg4)2.2 to bind chromatin, but instead appears to regulate the nuclear organization of gypsy insulator complexes. The results suggest that long-range interactions of insulator proteins are inhibited by sumoylation and that the establishment of chromatin domains can be regulated by SUMO conjugation. [ABSTRACT FROM AUTHOR]

Abstract: It was demonstrated previously that in erythroid chicken cells an extended upstream area of the α-globin gene domain is transcribed in both directions as a part of ggPRX gene and a part of a full domain transcript of the α-globin gene domain. Here, we show that both DNA chains of the above-mentioned region are transcribed in the same cells and that the corresponding transcripts coexist in nuclei. The data obtained suggest that cells possess a molecular mechanism which in some cases prevents the formation of dsRNA and subsequent destruction of both transcripts in spite of the presence of complementary RNA chains in the cell nucleus. [Copyright &y& Elsevier]

Provides information about the topics discussed during the workshop entitled "Epigenetics and Chromatin: Transcriptional Regulation and Beyond" held in Madrid, Spain. Role of epigenetic modifications in transcriptional activity; Specific residues and contexts in which histone modifications are mechanistically linked at many levels with DNA methylation; Chromatin changes, histone modifications and their effect on the transcriptional activity of the cell.

We have carried out analysis of lightning surge on overhead distribution lines by means of EMTP. We made a model for electric breakdown of a 14-m concrete pole with impulse voltage (rise time: 2 μ s) applied to the outer surface at the top of the concrete pole. We found that the transient impedance of the breakdown increased linearly before the breakdown and decreased exponentially after the breakdown. The measured voltage and current waveforms correspond to the calculated waveforms by regarding the impedance of the breakdown as resistance. Also we examined the impedance of flashover of an insulator with impulse voltage applied to the lines. The transient impedance of flashover is expressed approximately by the formula: Z(t) = A × exp(-(t - t0)/τ) (A = 1500 to 5000, τ = 3 × 10-8 to 5 × 10-8 s, t: time, t0: starting time of flashover). © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(1): 34–41, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20022 [ABSTRACT FROM AUTHOR]

Insulators are a class of elements that define independent domains of gene function. The Drosophila gypsy insulator is proposed to establish regulatory isolation by forming loop domains that constrain interactions between transcriptional control elem [ABSTRACT FROM AUTHOR]

The gypsy insulator is thought to play a role in nuclear organization and the establishment of higher order chromatin domains by bringing together several individual insulator sites to form rosette-like structures in the interphase nucleus. The Su(Hw) and Mod(mdg4) proteins are components of the gypsy insulator required for its effect on enhancer-promoter interactions. Using the yeast two-hybrid system, we show that the Mod(mdg4) protein can form homodimers, which can then interact with Su(Hw). The BTB domain of Mod(mdg4) is involved in homodimerization, whereas the C-terminal region of the protein is involved in interactions with the leucine zipper and adjacent regions of the Su(Hw) protein. Analyses using immunolocalization on polytene chromosomes confirm the involvement of these domains in mediating the interactions between these proteins. Studies using diploid interphase cells further suggest the contribution of these domains to the formation of rosettelike structures in the nucleus. The results provide a biochemical basis for the aggregation of multiple insulator sites and support the role of the gypsy insulator in nuclear organization. [ABSTRACT FROM AUTHOR]

In budding yeast, the telomeric DNA is flanked by a combination of two subtelomeric repetitive sequences, the X and Y′ elements. We have investigated the influence of these sequences on telomeric silencing. The telomere-proximal portion of either X or Y′ dampened silencing when located between the telomere and the reporter gene. These elements were named STARs, for subtelomeric anti-silencing regions. STARs can also counteract silencer-driven repression at the matingtype HML locus. When two STARs bracket a reporter gene, its expression is no longer influenced by surrounding silencing elements, although these are still active on a second reporter gene. In addition, an intervening STAR uncouples the silencing of neighboring genes. STARs thus display the hallmarks of insulators. Protection from silencing is recapitulated by multimerized oligonucleotides representing Tbf1p- and Reb1p-binding sites, as found in STARs. In contrast, sequences located more centromere proximal in X and Y′ elements reinforce silencing. They can promote silencing downstream of an insulated expressed domain. Overall, our results suggest that the silencing emanating from telomeres can be propagated in a discontinuous manner via a series of subtelomeric relay elements. [ABSTRACT FROM AUTHOR]

Transmission and distribution lines are sometimes struck by lightning and there is some risk of electrical puncture of suspension insulators due to high and steep lightning surge voltages, the solid insulating body of the insulators sometimes is punctured before external flashover in the air occurs. These characteristics were investigated on the insulators in the laboratory by using different steep impulse voltages. From the investigation results, both V-t characteristics of external flashover and internal puncture were obtained on the insulators. It was found that the puncture of the insulators is a matter of probability, depending on the dimensions of the insulators, steep impulse voltages and number of voltage application. Especially, the effect of number of voltage application on puncture probability was clarified and partial damage before complete puncture occurred. Based on the study results, a empirical equation relating to probability of puncture (P), impulse voltage (V) and number of voltage applications (N) was established. [ABSTRACT FROM AUTHOR]

This paper investigates the contamination of the surface of various insulators suspended in the air at a certain altitude and connected in series. It is shown that salt-proof dishes attached to pin-type insulators are effective against contamination. Exposure tests of insulators on Okinawa have been made since 1985 and the results are as follows: (1) The higher the placement of the insulator, the heavier the contamination. (2) The amount of contamination on the downward surface of the suspended insulators at the lowest position was considerably smaller than that of the insulators at the other positions. (3) The extent of contamination of the pin-type insulators with the salt-proof dishes was far less in comparison to that of pin-type insulators without salt-proof dishes. (4). The maximum equivalent salt-deposit density was related closely to the small amount of precipitation during the observation period and the occurrence of high wind speed, which was higher than 10 m/s. [ABSTRACT FROM AUTHOR]

The Drosophila gypsy retrotransposon disrupts gene activity by blocking the interactions of distal enhancers with target promoters. This enhancer-blocking activity is mediated by a 340 bp insulator DNA within gypsy. The insulator contains a cluster of binding sites for a zinc finger protein, suppressor of Hairy wing [su(Hw)]. Recent studies have shown that a second protein, mod(mdg4), is also important for normal insulator function. Mutations in mod(mdg4) exert paradoxical effects on different gypsy-induced phenotypes. For example, it enhances yellow2 but suppresses cut6. Here, we employ a stripe expression assay in transgenic embryos to investigate the role of mod(mdg4) in gypsy insulator activity. The insulator was inserted between defined enhancers and placed among divergently transcribed reporter genes (white and lacZ) containing distinct core promoter sequences. These assays indicate that mod(mdg4) is essential for the enhancer-blocking activity of the insulator DNA. Moreover, reductions in mod(mdg4)+ activity cause the insulator to function as a promoter-specific silencer that selectively represses white, but not lacZ. The repression of white does not affect the expression of the closely linked lacZ gene, suggesting that the insulator does not propagate changes in chromatin structure. These results provide an explanation for why mod(mdg4) exerts differential effects on different gypsy-induced mutations. [ABSTRACT FROM AUTHOR]

A room temperature ionic liquid (IL) is a molten salt with melting point below 100 °C and has extremely low vapor pressure, allowing use in a high vacuum chamber. In scanning electron microscopy, the ILs have been found to behave as electrically conductive materials and successfully applied for conductive coating of insulating specimens. It is well known that dynamic SIMS analysis of an insulator causes charge buildup and requires a conductive film coating and electron gun, which can distort depth profiling of metal elements. In this study, 1-ethyl-3-methylimidazolium tetrafluoroborate was employed to test the applicability for charge neutralization in depth profiling of insulators. Mass spectra were successfully obtained from the IL droplets deposited onto a Si substrate without charge buildup. Deposition of the IL onto fiber pulp samples enabled us to acquire continuous secondary ions from the pulp samples. It implies the potential use of the IL as a conductive film for depth profiling of metal elements in insulators such as SiO2 and SiN. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]