bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient far-infrared thermal bremsstrahlung radiation from a heterojunction bipolar transistor
Authors: Chung Pei-Kang , Yen Shun-Tung
Published: August 2015

We investigate the far-infrared thermal radiation properties of a heterojunction bipolar transistor. The device conveniently provides a high electric field for electrons to heat the lattice and the electron gas in a background with ions embedded. Because of very high effective temperature of the electron gas in the collector, the electron-ion bremsstrahlung makes efficient the thermal radiation in the far-infrared region. The transistor can yield a radiation power of 0.1 mW with the spectral region between 2 and 75 THz and a power conversion efficiency of 6 × 10−4. Such output contains a power of 20 μW in the low-frequency part (2–20 THz) of the spectrum.
Time-continuous Kerr electro-optic field mapping measurement under impulse voltage using array photodetector
Authors: Sima Wenxia , Song He , Yang Qing , Guo Hongda , Zahn Markus , Yang Ming
Published: August 2015

Space charge affects the electric field distribution in high voltage-stressed liquid dielectrics and can cause insulation degradation. This letter reports on research using a Kerr electro-optic measurement system with an array photodetector for Kerr electro-optic field mapping measurements in propylene carbonate under application of switching impulse voltages to investigate the electric field and space charge effects in high voltage-stressed liquid dielectrics. The electric field distribution between parallel aluminum electrodes is measured, and the results are compared with those measured using a charge-coupled device measurement system. The array photodetector measurement system has the advantages of higher sensitivity and higher time resolution because simultaneous optical Kerr measurements can be taken at multiple positions using a multi-element array photodetector. The results show that bipolar homo-charge injection occurs between the parallel aluminum electrodes. In the near future, this measurement system will be used in continuing research into the measurement of space charge effects using low Kerr constant liquids such as transformer oil.
On the internal energy of the classical two-dimensional one-component-plasma
Authors: Khrapak A. G. , Khrapak S. A.
Published: August 2015

We describe a new semi-phenomenological approach to estimate the internal energy of the classical one-component-plasma in two dimensions. This approach reproduces the Debye-Hückel asymptote in the limit of weak coupling, the ion disc asymptote in the limit of strong coupling, and provides reasonable interpolation between these two limits. The present analytic results are compared with those from other approximations as well as with existing data from numerical simulations.
Effects of diet on leather quality and longissimus muscle composition of three Ethiopian indigenous goat types
Authors: Tadesse Dereje , Urge Mengistu , Animut Getachew , Mekasha Yoseph
Published: August 2015

A 3 × 2 factorial experiment was carried out to evaluate the effect of breed or genotype and levels of concentrate on muscle composition and skin and leather quality characteristics. The three indigenous goat genotypes used were Bati, Hararghe highland (HH), and short-eared Somali (SS), (12/genotype) with an average initial weight of 15.2 ± 0.245 kg. The goats were all males ~1 year of age. After grouping based on their initial weight, they were randomly assigned to two levels of concentrate feeding (six goats per genotype per treatment) and fed for 90 days. The two concentrate feeding levels were C1 and C2, where goats were fed at 1% and 1.5% of their bodyweights, respectively. At the end of the study, all goats were slaughtered and samples were taken from the longissimus muscle for chemical composition analysis. The skins were weighed, preserved and processed into leather for physico-chemical analysis. The longissimus muscle of SS goats had higher (P < 0.05) fat content (7.01%) than Bati (6.05%) and HH (6.02%) goats. Feeding concentrate at 1.5% bodyweight increased carcass weights (P < 0.01), and increased the protein and fat contents of the longissimus muscle by ~5.4% and 3.5%, respectively. Similarly, goats under C2 feeding group had heavier skin than those under C1. However, Bati and HH goats produced 250 g more heavier leather than SS goats. Leathers made from skins of HH goats were thicker (1.56 mm) than those from Bati (1.32 mm) and SS goats (1.23 mm). Leathers from SS goats tended to have lower (P = 0.07) tear strength and higher (P = 0.05) fat content than those from Bati and HH goats. Goats fed C2 produced leathers with higher (P < 0.05) tear strength (51.6 N/mm) and fat content (6.2%) than those fed C1. In conclusion, the study revealed that the meat obtained from the three goat types had low to medium fat content that can meet the needs of diversified consumers. Moreover, they produced quality leather comparable to the quality standard set for good quality leather despite leathers from SS goats tending to have lower tear strength and higher fat content.
Meta-analysis of effect of a mono-component xylanase on the nutritional value of wheat supplemented with exogenous phytase for broiler chickens
Authors: Cowieson A. J. , Schliffka W. , Knap I. , Roos F. F. , Schoop R. , Wilson J. W.
Published: August 2015

A total of 1600 Ross broiler chicks were used in six separate balance studies (with equivalent protocols) to investigate the effect of an exogenous xylanase on the nutritional value of wheat (supplemented with a background of exogenous phytase) sourced from Asia, North America and Europe. The mean apparent metabolisable energy of the 10 batches of wheat per se was 13.4 MJ/kg DM and the addition of xylanase increased (P < 0.001) this by an average of 0.43 MJ/kg DM (~3.2%). Apparent ileal digestibility of nitrogen in the 10 batches of wheat per se was 69.8% and xylanase addition increased (P < 0.001) this by 2%. The apparent ileal disappearance of soluble and insoluble non-starch polysaccharides (NSP) was –53% and +5%, respectively and xylanase addition increased these by 28% and 15%, respectively. The apparent ileal disappearance of total arabinose + xylose was –10% and xylanase increased this by 21%. The apparent ileal flow of fucose was 0.38 g/kg DM intake and xylanase addition reduced (P < 0.05) this by 0.03 g/kg DM intake. There was a significant negative correlation between the apparent ileal flow of fucose and the digestibility of nitrogen and energy in the wheat and the wheat plus xylanase. These results demonstrate the continued effectiveness of exogenous xylanase to enhance the nutritional value of wheat for broiler chickens. Furthermore, the degradation of NSP fractions is confirmatory of both soluble and insoluble fibre hydrolysis in the intestine of the birds. Finally, although de-caging, viscosity amelioration and microbial changes are likely to be involved, the reduced flow of fucose in the intestine of birds fed wheat with supplemental xylanase is indicative of reduced endogenous (mucin) loss with net energy and enteric health implications. The effect of wheat pentosans and xylanase on intestinal secretion and endogenous protein and energy loss is an area for future study. Finally, the results presented herein suggest a reduction in soluble NSP concentrations in wheat over the past 2–3 decades, which is a trend that may explain anecdotal observations that the incidence of so-called sticky wheats is in decline. Systematic assessment of the implications of changing substrate concentrations and characteristics for new xylanase development is warranted.
Transgenerational effects of a hypercaloric diet
Authors: Joaquim A. O. , Coelho C. P. , Motta P. Dias , Bondan E. F. , Teodorov E. , Martins M. F. M. , Kirsten T. B. , Casarin R. C. V. , Bonamin L. V. , Bernardi M. M.
Published: August 2015

The effects of a maternal hypercaloric diet (HD) during puberty and early adulthood on neuroimmune aspects in offspring were investigated. In female rats of the F0 generation and male rats of the F1 generation, bodyweight (BW) gain, retroperitoneal fat (RPF) weight, the number of hypodermic adipocytes (HAs) and expression of glial fibrillary acidic protein (GFAP) were measured in hypothalamic astrocytes. On Postnatal Day 50, the F1 pups were challenged with lipopolysaccharide (LPS, 100 µg kg–1, s.c.) or an equal volume of saline (S), and behaviour in the open field test was evaluated, as were plasma neuropeptide and cytokine concentrations. The maternal HD caused the female F0 rats to become overweight. The F1 offspring of dams fed the HD and challenged with saline (HDS group) exhibited increases in BW gain, RPF weight and in the number of large HAs and a decrease in GFAP immunoreactivity. F1 offspring of dams fed the HD and challenged with LPS (HDLPS group) exhibited decreases in BW gain, RPF weight and GFAP immunoreactivity, but no differences were observed in the number of larger and small HAs. Plasma tumour necrosis factor-α concentrations were high in the HDS and HDLPS groups. Thus, the maternal HD during puberty and early adulthood caused the F1 generation to become overweight despite the fact that they received a normocaloric diet. These results indicate a transgenerational effect of the HD that may occur, in part, through permanent changes in immune system programming. The attenuation of neuroinflammation biomarkers after LPS administration may have resulted in a decrease in the number of adipocytes, which, in turn, reduced cytokine, adipokine and chemokine levels, which are able to recruit inflammatory cells in adipose tissue.
The COUP-TFII/Neuropilin-2 is a molecular switch steering diencephalon-derived GABAergic neurons in the developing mouse brain
Authors: Kanatani Shigeaki , Honda Takao , Aramaki Michihiko , Hayashi Kanehiro , Kubo Ken-ichiro , Ishida Mami , Tanaka Daisuke H. , Kawauchi Takeshi , Sekine Katsutoshi , Kusuzawa Sayaka , Kawasaki Takahiko , Hirata Tatsumi , Tabata Hidenori , Uhlén Per , Nakajima Kazunori
Published: August 2015

Significance

Recently the preoptic area (POa) has been shown to be a source of GABAergic neurons in the medial amygdala and cerebral cortex, where they are thought to play a pivotal role in emotions and intelligence, respectively. However, it is unknown how the POa-derived neurons migrate and selectively segregate into either the amygdala or cortex. By using focal in utero labeling of the POa, we show that switching on/off the transcription factor COUP-TFII (Chicken ovalbumin upstream promoter transcription factor II) and the receptor Neuropilin-2 (Nrp2) directs the POa-derived neurons toward either the amygdala or cortex. Our study revealed an essential role of COUP-TFII/Nrp2 expression dynamics in the development of the amygdala and cortex.
Bacterial SPOR domains are recruited to septal peptidoglycan by binding to glycan strands that lack stem peptides
Authors: Yahashiri Atsushi , Jorgenson Matthew A. , Weiss David S.
Published: August 2015

Significance

Cell division in bacteria is mediated by a large collection of proteins that assemble into a contractile ring at the division site. Understanding how these proteins are targeted to that site is important for understanding how division is spatially and temporally regulated. Here we demonstrate that a septal-targeting domain found in many bacterial cell-division proteins works by binding to a cell-wall structure that is present only transiently during cell division. These findings support a model for how different cell-wall hydrolases work together during separation of daughter cells and suggest a mechanism for coordinating synthesis and degradation of the cell wall during division.
Maize death acids, 9-lipoxygenase–derived cyclopente(a)nones, display activity as cytotoxic phytoalexins and transcriptional mediators
Authors: Christensen Shawn A. , Huffaker Alisa , Kaplan Fatma , Sims James , Ziemann Sebastian , Doehlemann Gunther , Ji Lexiang , Schmitz Robert J. , Kolomiets Michael V. , Alborn Hans T. , Mori Naoki , Jander Georg , Ni Xinzhi , Sartor Ryan C. , Byers Sara , Abdo Zaid , Schmelz Eric A.
Published: August 2015

Significance

In plants, 12-oxo-phytodienoic acid (12-OPDA) and jasmonic acid are key 13-lipoxygenase-derived linolenate oxidation products termed jasmonates that regulate diverse processes in development and innate immunity. A less-studied metabolic pathway branch is generated by 9-lipoxygenase activity on linoleic acid, enabling the production of 10-oxo-11-phytoenoic acid (10-OPEA). In maize, fungal infection by southern leaf blight (
Cochliobolus heterostrophus
) results in the localized production of 10-OPEA, and a series of related 12- and 14-carbon cyclopente(a)nones, collectively termed “death acids” (DAs). DAs far exceed jasmonates in abundance within infected tissues, display direct phytoalexin activity against biotic agents, mediate defense gene expression, and can promote cytotoxicity resulting in cell death. Collectively DA activities are consistent with specialized local roles in plant defense.
Contact-dependent growth inhibition toxins exploit multiple independent cell-entry pathways
Authors: Willett Julia L. E. , Gucinski Grant C. , Fatherree Jackson P. , Low David A. , Hayes Christopher S.
Published: August 2015

Significance

Gram-negative bacteria use contact-dependent growth inhibition (CDI) systems to bind neighboring bacteria and deliver diverse nuclease toxins that inhibit target-cell growth. This process requires toxin transport across the outer and inner membranes of target bacteria to reach DNA and RNA substrates in the cytoplasm. Our data indicate that CDI toxins contain a variable domain that specifies the entry pathway into target bacteria. These “translocation domains” exploit specific integral membrane proteins to deliver linked nuclease domains into the cytoplasm. We also find that CDI translocation domains can be exchanged between CdiA C-terminal toxin domains to deliver nucleases via different routes. These findings reveal a versatile protein-transport mechanism that could potentially be harnessed to deliver other antimicrobial cargoes into Gram-negative bacteria.
Cross-strand binding of TFAM to a single mtDNA molecule forms the mitochondrial nucleoid
Authors: Kukat Christian , Davies Karen M. , Wurm Christian A. , Spåhr Henrik , Bonekamp Nina A. , Kühl Inge , Joos Friederike , Polosa Paola Loguercio , Park Chan Bae , Posse Viktor , Falkenberg Maria , Jakobs Stefan , Kühlbrandt Werner , Larsson Nils-Göran
Published: August 2015

Significance

Altered expression of mitochondrial DNA (mtDNA) is heavily implicated in human disease and aging, but the basic organizational unit of mtDNA, the mitochondrial nucleoid, is poorly understood. Here, we have used a combination of biochemistry, superresolution microscopy, and electron microscopy to show that mammalian mitochondrial nucleoids have an irregular ellipsoidal shape and typically contain a single copy of mtDNA. Furthermore, we show that the nucleoid ultrastructure is independent of cellular mtDNA copy number and that the core nucleoid structure is formed by cross-strand binding of mitochondrial transcription factor A (TFAM) to a single copy of mtDNA. The clarification of the ultrastructure of the mammalian mitochondrial nucleoid provides the fundamental basis for the understanding of regulation of mtDNA maintenance and expression in mammals.
NLRP3 deficiency protects from type 1 diabetes through the regulation of chemotaxis into the pancreatic islets
Authors: Hu Changyun , Ding Heyuan , Li Yangyang , Pearson James A. , Zhang Xiaojun , Flavell Richard A. , Wong F. Susan , Wen Li
Published: August 2015

Significance

Our study demonstrated that the nucleotidebinding oligomerization domain, leucine-rich repeat and pyrin domaincontaining protein 3 (NLRP3) pathway plays an important role in type 1 diabetes (T1D) using a mouse model. NLRP3 is critical for chemokine receptors CCR5 and CXCR3 expression on T cells, influencing pathogenic T-cell migration to the islets. It also affects the chemokines CCL5 and CXCL10 expression in the islets, preventing pathogenic T cells from infiltration. Targeting this pathway may be useful in prevention and treatment of T1D as it affects both immune cells and pancreatic beta cells.
Positive feedback between RNA-binding protein HuD and transcription factor SATB1 promotes neurogenesis
Authors: Wang Feifei , Tidei Joseph J. , Polich Eric D. , Gao Yu , Zhao Huashan , Perrone-Bizzozero Nora I. , Guo Weixiang , Zhao Xinyu
Published: August 2015

Significance

RNA-binding proteins play central roles in posttranscriptional gene regulation. HuD is one of the first markers used for neuronal lineage; however, the function of HuD in neural stem cell differentiation is largely unexplored. In addition, although it has been shown that
HuD
mRNA levels increase during neuronal differentiation, to date few studies have examined the mechanism controlling the expression of HuD during neural differentiation. In this study, we investigated the role of HuD in neural stem cell differentiation and uncovered an underlying molecular mechanism. Our results unveil a novel positive feedback network between an RNA-binding protein and a transcription factor that plays critical regulatory roles during neuronal differentiation.
Isotope-specific and amino acid-specific heavy atom substitutions alter barrier crossing in human purine nucleoside phosphorylase
Authors: Suarez Javier , Schramm Vern L.
Published: August 2015

Significance

Enzyme catalytic cycles involve conformational changes that limit the usual steady-state catalytic rate to millisecond turnover numbers. Covalent bond changes occur at transition states with femtosecond lifetimes, a factor of 10
12
faster than steady-state catalysis. Coupling millisecond and femtosecond events is unlikely. Femtosecond bond vibrational events can be explored by heavy isotope substitution into enzyme proteins. Heavy-enzyme purine nucleoside phosphorylase was used to explore bond vibrational coupling to catalytic site chemistry. Three distinct protein labeling patterns in purine nucleoside phosphorylase gave reduced catalytic site chemistry rates. The pattern establishes coupling between catalytic site bond vibrational modes and barrier crossing in purine nucleoside phosphorylase.
Deep two-photon brain imaging with a red-shifted fluorometric Ca
2+
indicator
Authors: Tischbirek Carsten , Birkner Antje , Jia Hongbo , Sakmann Bert , Konnerth Arthur
Published: August 2015

Significance

We introduce a two-photon imaging method with improved depth penetration for the recording of neuronal activity with single-cell resolution in the intact brain of living animals. This method relies on the use of the fluorometric Ca
2+
-sensitive dye Cal-590, which is effectively excited by infrared light (1,050 nm). By combining population Ca
2+
imaging and electrical recordings in vivo, we demonstrate that neuronal activity can be monitored in all six layers of the mouse cortex. In combination with spectrally different Ca
2+
indicators, Cal-590 can be used for the simultaneous imaging of neuronal activity in distinct neuronal populations.
Effect of aging on muscle mitochondrial substrate utilization in humans
Authors: Petersen Kitt Falk , Morino Katsutaro , Alves Tiago C. , Kibbey Richard G. , Dufour Sylvie , Sono Saki , Yoo Peter S. , Cline Gary W. , Shulman Gerald I.
Published: August 2015

Significance

Approximately 40% of Americans over the age of 65 suffer from impaired glucose tolerance or type 2 diabetes; however, the pathogenesis of aging-associated reductions in glucose metabolism is poorly understood. Aging is associated with muscle insulin resistance, increased intramyocellular fat content, and reductions in rates of muscle mitochondrial activity. To further examine the potential role of age-associated alterations in mitochondrial metabolism, we applied a novel method to assess muscle specific rates of mitochondrial glucose and fat oxidation and demonstrate that aging is also associated with a marked inability of mitochondria to switch from lipid to glucose oxidation on insulin stimulation, which may further contribute to dysregulated glucose and lipid metabolism in the elderly.
Hepatic ANGPTL3 regulates adipose tissue energy homeostasis
Authors: Wang Yan , McNutt Markey C. , Banfi Serena , Levin Michael G. , Holland William L. , Gusarova Viktoria , Gromada Jesper , Cohen Jonathan C. , Hobbs Helen H.
Published: August 2015

Significance

Here we show that angiopoietin-like protein 3 (ANGPTL3) plays a major role in the trafficking of energy substrates to either storage or oxidative tissues in response to food intake. During fasting, adipose tissue releases fatty acids into the circulation for uptake by oxidative tissues. After feeding, the flow of fatty acids is reversed and the adipose tissue is replenished. In mice lacking ANGPTL3, the uptake of fatty acids from the circulation into adipose tissue was markedly reduced after refeeding. Triglyceride stores were maintained by increasing glucose uptake and converting it to fatty acids and triglycerides. Thus, ANGPTL3 acts like a hormone that is produced by the liver to coordinate substrate trafficking to peripheral tissues in response to dietary intake.
Mast cells and dendritic cells form synapses that facilitate antigen transfer for T cell activation
Authors: Carroll-Portillo Amanda , Cannon Judy L. , te Riet Joost , Holmes Anna , Kawakami Yuko , Kawakami Toshiaki , Cambi Alessandra , Lidke Diane S.
Published: August 2015

Mast cells (MCs) produce soluble mediators such as histamine and prostaglandins that are known to influence dendritic cell (DC) function by stimulating maturation and antigen processing. Whether direct cell–cell interactions are important in modulating MC/DC function is unclear. In this paper, we show that direct contact between MCs and DCs occurs and plays an important role in modulating the immune response. Activation of MCs through FcεRI cross-linking triggers the formation of stable cell–cell interactions with immature DCs that are reminiscent of the immunological synapse. Direct cellular contact differentially regulates the secreted cytokine profile, indicating that MC modulation of DC populations is influenced by the nature of their interaction. Synapse formation requires integrin engagement and facilitates the transfer of internalized MC-specific antigen from MCs to DCs. The transferred material is ultimately processed and presented by DCs and can activate T cells. The physiological outcomes of the MC–DC synapse suggest a new role for intercellular crosstalk in defining the immune response.
A novel mouse model identifies cooperating mutations and therapeutic targets critical for chronic myeloid leukemia progression
Authors: Giotopoulos George , van der Weyden Louise , Osaki Hikari , Rust Alistair G. , Gallipoli Paolo , Meduri Eshwar , Horton Sarah J. , Chan Wai-In , Foster Donna , Prinjha Rab K. , Pimanda John E. , Tenen Daniel G. , Vassiliou George S. , Koschmieder Steffen , Adams David J. , Huntly Brian J.P.
Published: August 2015

The introduction of highly selective ABL-tyrosine kinase inhibitors (TKIs) has revolutionized therapy for chronic myeloid leukemia (CML). However, TKIs are only efficacious in the chronic phase of the disease and effective therapies for TKI-refractory CML, or after progression to blast crisis (BC), are lacking. Whereas the chronic phase of CML is dependent on BCR-ABL, additional mutations are required for progression to BC. However, the identity of these mutations and the pathways they affect are poorly understood, hampering our ability to identify therapeutic targets and improve outcomes. Here, we describe a novel mouse model that allows identification of mechanisms of BC progression in an unbiased and tractable manner, using transposon-based insertional mutagenesis on the background of chronic phase CML. Our BC model is the first to faithfully recapitulate the phenotype, cellular and molecular biology of human CML progression. We report a heterogeneous and unique pattern of insertions identifying known and novel candidate genes and demonstrate that these pathways drive disease progression and provide potential targets for novel therapeutic strategies. Our model greatly informs the biology of CML progression and provides a potent resource for the development of candidate therapies to improve the dismal outcomes in this highly aggressive disease.
Suppression of Th2 and Tfh immune reactions by Nr4a receptors in mature T reg cells
Authors: Sekiya Takashi , Kondo Taisuke , Shichita Takashi , Morita Rimpei , Ichinose Hiroshi , Yoshimura Akihiko
Published: August 2015

Regulatory T (T reg) cells are central mediators of immune suppression. As such, T reg cells are characterized by a distinct pattern of gene expression, which includes up-regulation of immunosuppressive genes and silencing of inflammatory cytokine genes. Although an increasing number of transcription factors that regulate T reg cells have been identified, the mechanisms by which the T reg cell–specific transcriptional program is maintained and executed remain largely unknown. The Nr4a family of nuclear orphan receptors, which we recently identified as essential for the development of T reg cells, is highly expressed in mature T reg cells as well, suggesting that Nr4a factors play important roles even beyond T reg cell development. Here, we showed that deletion of Nr4a genes specifically in T reg cells caused fatal systemic immunopathology. Nr4a-deficient T reg cells exhibited global alteration of the expression of genes which specify the T reg cell lineage, including reduction of Foxp3 and Ikzf4. Furthermore, Nr4a deficiency abrogated T reg cell suppressive activities and accelerated conversion to cells with Th2 and follicular helper T (Tfh) effector-like characteristics, with heightened expression of Th2 and Tfh cytokine genes. These findings demonstrate that Nr4a factors play crucial roles in mature T reg cells by directly controlling a genetic program indispensable for T reg cell maintenance and function.
Cysteinyl leukotrienes mediate lymphokine killer activity induced by NKG2D and IL-15 in cytotoxic T cells during celiac disease
Authors: Tang Fangming , Sally Benjamin , Lesko Kathryn , Discepolo Valentina , Abadie Valerie , Ciszewski Cezary , Semrad Carol , Guandalini Stefano , Kupfer Sonia S. , Jabri Bana
Published: August 2015

Eicosanoids are inflammatory mediators that play a key but incompletely understood role in linking the innate and adaptive immune systems. Here, we show that cytotoxic effector T cells (CTLs) are capable of both producing and responding to cysteinyl leukotrienes (CystLTs), allowing for the killing of target cells in a T cell receptor–independent manner. This process is dependent on the natural killer receptor NKG2D and exposure to IL-15, a cytokine induced in distressed tissues. IL-15 and NKG2D signaling drives the up-regulation of key enzymes implicated in the synthesis of CystLTs, as well as the expression of CystLT receptors, suggesting a positive feedback loop. Finally, although the CystLT pathway has been previously linked to various allergic disorders, we provide unexpected evidence for its involvement in the pathogenesis of celiac disease (CD), a T helper 1 cell–mediated enteropathy induced by gluten. These findings provide new insights into the cytolytic signaling pathway of NKG2D and the pathogenesis of organ-specific immune disorders. Furthermore, they suggest that the blockade of CystLT receptors may represent a potent therapeutic target for CD or potentially other autoimmune disorders in which NKG2D has been implicated.
Effects of central electron cyclotron power on plasma rotation and on triggerless onset of NTMs in the TCV tokamak
Authors: Lazzaro E. , Nowak S. , Sauter O. , Canal G. , Duval B. , Federspiel L. , Karpushov A.N. , Kim D. , Reimerdes H. , Rossel J. , Testa D. , Wagner D.
Published: August 2015

Experiments in the TCV tokamak show that high power central electron cyclotron heating (ECH) and current drive (ECCD) produce significant direct modification of the plasma rotation profile, as well as an effect on the equilibrium current density profile. In a regime of unsteady rotation, these effects contribute to the onset of neoclassical tearing instabilities, in the absence of triggers such as sawteeth, edge localised modes (ELMS) or relevant ‘error’ fields. In turn the growing tearing modes' breaking axisymmetry provides a nonlinear magnetic torque which converts the power absorption in a co-directed rotation with a flattening of the profile at the rational surfaces. The experimental results are presented and discussed in the context of theoretical models of neoclassical toroidal viscosity and ion inertial effects.
Nonlinear damping and quasi-linear modelling
Authors: Elliott S. J. , Tehrani M. Ghandchi , Langley R. S.
Published: August 2015

The mechanism of energy dissipation in mechanical systems is often nonlinear. Even though there may be other forms of nonlinearity in the dynamics, nonlinear damping is the dominant source of nonlinearity in a number of practical systems. The analysis of such systems is simplified by the fact that they show no jump or bifurcation behaviour, and indeed can often be well represented by an equivalent linear system, whose damping parameters depend on the form and amplitude of the excitation, in a ‘quasi-linear’ model. The diverse sources of nonlinear damping are first reviewed in this paper, before some example systems are analysed, initially for sinusoidal and then for random excitation. For simplicity, it is assumed that the system is stable and that the nonlinear damping force depends on the
n
th power of the velocity. For sinusoidal excitation, it is shown that the response is often also almost sinusoidal, and methods for calculating the amplitude are described based on the harmonic balance method, which is closely related to the describing function method used in control engineering. For random excitation, several methods of analysis are shown to be equivalent. In general, iterative methods need to be used to calculate the equivalent linear damper, since its value depends on the system’s response, which itself depends on the value of the equivalent linear damper. The power dissipation of the equivalent linear damper, for both sinusoidal and random cases, matches that dissipated by the nonlinear damper, providing both a firm theoretical basis for this modelling approach and clear physical insight. Finally, practical examples of nonlinear damping are discussed: in microspeakers, vibration isolation, energy harvesting and the mechanical response of the cochlea.
Structural optimization for nonlinear dynamic response
Authors: Dou Suguang , Strachan B. Scott , Shaw Steven W. , Jensen Jakob S.
Published: August 2015

Much is known about the nonlinear resonant response of mechanical systems, but methods for the systematic design of structures that optimize aspects of these responses have received little attention. Progress in this area is particularly important in the area of micro-systems, where nonlinear resonant behaviour is being used for a variety of applications in sensing and signal conditioning. In this work, we describe a computational method that provides a systematic means for manipulating and optimizing features of nonlinear resonant responses of mechanical structures that are described by a single vibrating mode, or by a pair of internally resonant modes. The approach combines techniques from nonlinear dynamics, computational mechanics and optimization, and it allows one to relate the geometric and material properties of structural elements to terms in the normal form for a given resonance condition, thereby providing a means for tailoring its nonlinear response. The method is applied to the fundamental nonlinear resonance of a clamped–clamped beam and to the coupled mode response of a frame structure, and the results show that one can modify essential normal form coefficients by an order of magnitude by relatively simple changes in the shape of these elements. We expect the proposed approach, and its extensions, to be useful for the design of systems used for fundamental studies of nonlinear behaviour as well as for the development of commercial devices that exploit nonlinear behaviour.
Modal testing for model validation of structures with discrete nonlinearities
Authors: Ewins D. J. , Weekes B. , delli Carri A.
Published: August 2015

Model validation using data from modal tests is now widely practiced in many industries for advanced structural dynamic design analysis, especially where structural integrity is a primary requirement. These industries tend to demand highly efficient designs for their critical structures which, as a result, are increasingly operating in regimes where traditional linearity assumptions are no longer adequate. In particular, many modern structures are found to contain localized areas, often around joints or boundaries, where the actual mechanical behaviour is far from linear. Such structures need to have appropriate representation of these nonlinear features incorporated into the otherwise largely linear models that are used for design and operation. This paper proposes an approach to this task which is an extension of existing linear techniques, especially in the testing phase, involving only just as much nonlinear analysis as is necessary to construct a model which is good enough, or ‘valid’: i.e. capable of predicting the nonlinear response behaviour of the structure under all in-service operating and test conditions with a prescribed accuracy. A short-list of methods described in the recent literature categorized using our framework is given, which identifies those areas in which further development is most urgently required.
Phosphoribulokinase mediates nitrogenase-induced carbon dioxide fixation gene repression in Rhodobacter sphaeroides
Authors: Farmer Ryan M. , Tabita F. Robert
Published: August 2015

In many organisms there is a balance between carbon and nitrogen metabolism. These observations extend to the nitrogen-fixing, nonsulfur purple bacteria, which have the classic family of P(II) regulators that coordinate signals of carbon and nitrogen status to regulate nitrogen metabolism. Curiously, these organisms also possess a reverse mechanism to regulate carbon metabolism based on cellular nitrogen status. In this work, studies in Rhodobacter sphaeroides firmly established that the activity of the enzyme that catalyses nitrogen fixation, nitrogenase, induces a signal that leads to repression of genes encoding enzymes of the Calvin–Benson–Bassham (CBB) CO2 fixation pathway. Additionally, genetic and metabolomic experiments revealed that NADH-activated phosphoribulokinase is an intermediate in the signalling pathway. Thus, nitrogenase activity appears to be linked to cbb gene repression through phosphoribulokinase.
The beetle amnion and serosa functionally interact as apposed epithelia
Authors: Koelzer Stefan , Hilbrant Maarten , Horn Thorsten , Panfilio Kristen A.
Published: August 2015

Unlike passive rupture of the human chorioamnion at birth, the insect extraembryonic (EE) tissues – the amnion and serosa – actively rupture and withdraw in late embryogenesis. Despite its importance for successful development, EE morphogenesis remains poorly understood. Contradicting the hypothesis of a single, fused EE membrane, we show that both tissues persist as discrete epithelia within a bilayer, using new tissue-specific EGFP transgenic lines in the beetleTribolium castaneum. Quantitative live imaging analyses show that the amnion initiates EE rupture in a specialized anterior-ventral cap, while RNAi manipulation of EE tissue complement and function reveals that the serosa is autonomously contractile. Thus the bilayer efficiently coordinates the amnion as initiator and serosa as driver to achieve withdrawal. The novel bilayer architecture may reflect evolutionary changes in the EE tissues specific to holometabolous insects. More generally, tissue apposition in a bilayer exemplifies a high degree of functional interaction between developing epithelia.
Phylogeographic Inference Using Approximate Likelihoods
Authors: O’Meara Brian C. , Jackson Nathan D. , Morales Ariadna , Carstens Bryan C.
Published: August 2015

The demographic history of most species is complex, with multiple evolutionary processes combining to shape the observed patterns of genetic diversity. To infer this history, the discipline of phylogeography has (to date) used models that simplify the historical demography of the focal organism, for example by assuming or ignoring ongoing gene flow between populations or by requiringa priorispecification of divergence history. Since no single model incorporates every possible evolutionary process, researchers rely on intuition to choose the models that they use to analyze their data. Here, we develop an approach to circumvent this reliance on intuition. PHRAPL allows users to calculate the probability of a large number of demographic histories given their data, enabling them to identify the optimal model and produce accurate parameter estimates for a given system. Using PHRAPL, we reanalyze data from 19 recent phylogeographic investigations. Results indicate that the optimal models for most datasets parameterize both gene flow and population divergence, and suggest that species tree methods (which do not consider gene flow) are overly simplistic for most phylogeographic systems. These results highlight the importance of phylogeographic model selection, and reinforce the role of phylogeography as a bridge between population genetics and phylogenetics.
Insights into stabilizing interactions in the distorted domain-swapped dimer ofSalmonella typhimuriumsurvival protein
Authors: Mathiharan Yamuna Kalyani , Savithri H. S. , Murthy M. R. N.
Published: August 2015

The survival protein SurE fromSalmonella typhimurium(StSurE) is a dimeric protein that functions as a phosphatase. SurE dimers are formed by the swapping of a loop with a pair of β-strands and a C-terminal helix between two protomers. In a previous study, the Asp230 and His234 residues were mutated to Ala to abolish a hydrogen bond that was thought to be crucial for C-terminal helix swapping. These mutations led to functionally inactive and distorted dimers in which the two protomers were related by a rotation of 167°. New salt bridges involving Glu112 were observed in the dimeric interface of the H234A and D230A/H234A mutants. To explore the role of these salt bridges in the stability of the distorted structure, E112A, E112A/D230A, E112A/H234A, E112A/D230A/H234A, R179L/H180A/H234A and E112A/R179L/H180A/H234A mutants were constructed. X-ray crystal structures of the E112A, E112A/H234A and E112A/D230A mutants could be determined. The dimeric structures of the E112A and E112A/H234A mutants were similar to that of native SurE, while the E112A/D230A mutant had a residual rotation of 11° between theBchains upon superposition of theAchains of the mutant and native dimers. The native dimeric structure was nearly restored in the E112A/H234A mutant, suggesting that the new salt bridge observed in the H234A and D230A/H234A mutants was indeed responsible for the stability of their distorted structures. Catalytic activity was also restored in these mutants, implying that appropriate dimeric organization is necessary for the activity of SurE.
Crystallographic studies of the structured core domain of Knr4 fromSaccharomyces cerevisiae
Authors: Julien Sylviane , Tondl Patrick , Durand Fabien , Dagkessamanskaia Adilia , van Tilbeurgh Herman , François Jean Marie , Mourey Lionel , Zerbib Didier , Martin-Yken Hélène , Maveyraud Laurent
Published: August 2015

The potentially structured core domain of the intrinsically disordered protein Knr4 fromSaccharomyces cerevisiae, comprising residues 80–340, was expressed inEscherichia coliand crystallized using the hanging-drop vapour-diffusion method. Selenomethionine-containing (SeMet) protein was also purified and crystallized. Crystals of both proteins belonged to space groupP6522, with unit-cell parametersa=b= 112.44,c= 265.21 Å for the native protein anda = b = 112.49,c= 262.21 Å for the SeMet protein, and diffracted to 3.50 and 3.60 Å resolution, respectively. There are two molecules in the asymmetric unit related by a twofold axis. The anomalous signal of selenium was recorded and yielded an electron-density map of sufficient quality to allow the identification of secondary-structure elements.
Cloning, expression, purification and crystallization of a pair of novel virulence factors, SghA and SghR, fromAgrobacterium tumefaciens
Authors: Ye Fuzhou , Wang Chao , Fu Qinqin , Zhang Lian-hui , Gao Yong-gui
Published: August 2015

Two proteins, SghA and SghR, which were recently identified and characterized as novel bacterial virulence factors regulating the infection of plant hosts byAgrobacterium, were cloned, overexpressed and purified with high yield. Both SghA and SghR form dimers in solution. The purified SghA and SghR were crystallized and the crystals diffracted to 1.9 and 2.1 Å resolution, respectively. Data were collected and processed, and the crystallographic parameters were within acceptable ranges. These results will help in the determination of their structures in order to uncover the molecular mechanism of how these two proteins together control the release of plant defence signals against agrobacteria during pathogen–host interaction.
The structure of Tim50(164–361) suggests the mechanism by which Tim50 receives mitochondrial presequences
Authors: Li Jingzhi , Sha Bingdong
Published: August 2015

Mitochondrial preproteins are transported through the translocase of the outer membrane (TOM) complex. Tim50 and Tim23 then transfer preproteins with N-terminal targeting presequences through the intermembrane space (IMS) across the inner membrane. The crystal structure of the IMS domain of Tim50 [Tim50(164–361)] has previously been determined to 1.83 Å resolution. Here, the crystal structure of Tim50(164–361) at 2.67 Å resolution that was crystallized using a different condition is reported. Compared with the previously determined Tim50(164–361) structure, significant conformational changes occur within the protruding β-hairpin of Tim50 and the nearby helix A2. These findings indicate that the IMS domain of Tim50 exhibits significant structural plasticity within the putative presequence-binding groove, which may play important roles in the function of Tim50 as a receptor protein in the TIM complex that interacts with the presequence and multiple other proteins. More interestingly, the crystal packing indicates that helix A1 from the neighboring monomer docks into the putative presequence-binding groove of Tim50(164–361), which may mimic the scenario of Tim50 and the presequence complex. Tim50 may recognize and bind the presequence helix by utilizing the inner side of the protruding β-hairpin through hydrophobic interactions. Therefore, the protruding β-hairpin of Tim50 may play critical roles in receiving the presequence and recruiting Tim23 for subsequent protein translocations.
Crystallization and X-ray diffraction studies of a two-domain laccase fromStreptomyces griseoflavus
Authors: Tishchenko Svetlana , Gabdulkhakov Azat , Trubitsina Liubov , Lisov Alexander , Zakharova Marina , Leontievsky Alexey
Published: August 2015

Laccase (EC 1.10.3.2) is one of the most common copper-containing oxidases; it is found in many organisms and catalyzes the oxidation of primarily phenolic compounds by oxygen. Two-domain laccases have unusual thermostability, resistance to inhibitors and an alkaline optimum of activity. The causes of these properties in two-domain laccases are poorly understood. A recombinant two-domain laccase (SgfSL) was cloned from the genome ofStreptomyces griseoflavusAc-993, expressed inEscherichia coliand purified to homogeneity. The crystals of SgfSL belonged to the monoclinic space groupP21, with unit-cell parametersa= 74.64,b= 94.72,c= 117.40 Å, β = 90.672°, and diffraction data were collected to 2.0 Å resolution using a synchrotron-radiation source. Two functional trimers per asymmetric unit correspond to a Matthews coefficient of 1.99 Å3 Da−1according to the monomer molecular weight of 35.6 kDa.
Crystal structure of aqua-1κO-{μ-2-[(2-hydroxyethyl)methylamino]ethanolato-2:1κ4O1,N,O2:O1}[μ-2,2′-(methylimino)diethanolato-1:2κ4O,N,O′:O]dithiocyanato-1κN,2κN-chromium(III)copper(II)
Authors: Rusanova Julia A. , Semenaka Valentina V. , Dyakonenko Viktoriya V. , Shishkin Oleg V.
Published: August 2015

The title compound, [CrCu(C5H11NO2)(C5H12NO2)(NCS)2(H2O)] or [Cr(μ-mdea)Cu(μ-Hmdea)(NCS)2H2O], (where mdeaH2isN-methylethanolamine, C5H13NO2) is formed as a neutral heterometal CuII/CrIIIcomplex. The molecular structure of the complex is based on a binuclear {CuCr(μ-O)2} core. The coordination environment of each metal atom involves theN,O,Oatoms of the tridentate ligand, one bridging O atom of the ligand and the N atom of the thiocyanato ligands. The CuIIion adopts a distorted square-pyramidal coordination while the CrIIIion has a distorted octahedral coordination geometry completed by the aqua ligand. In the crystal, the binuclear complexes are linkedviatwo pairs of O—H...O hydrogen bonds to form inversion dimers, which are arranged in columns parallel to theaaxis. In the μ-mdea ligand two –CH2groups and the methyl group were refined as disordered over two sets of sites with equal occupancies. The structure was refined as a two-component twin with a twin scale factor of 0.242 (1).
Crystal structure of 2,4-dinitrophenyl 4-methylbenzenesulfonate: a new polymorph
Authors: Cooley Tyler A. , Riley Sean , Biros Shannon M. , Staples Richard J. , Ngassa Felix N.
Published: August 2015

The title compound, C13H10N2O7S, was synthesizedviaa nucleophilic substitution reaction between 2,4-dinitrophenol andp-toluenesulfonyl chloride. This crystal structure is a polymorph of CSD entry WUVYUH [Vembuet al.(2003).Acta Cryst, E59, o378–380]. The aromatic substituents on the sulfonate group are orientedgaucheto one another with a C—O—S—C torsion angle of −62.0 (3)°. The supramolecular features that contribute to the crystal stability are offset π–π [centroid–centroid distance = 3.729 (2) Å] and multiple C—H...O interactions.
The new middlemen of the digital age: the case of cinema
Authors: Simon Jean Paul , Benghozi Pierre Jean , Salvador Elisa
Published: August 2015

Purpose

– The purpose of this paper is to enquire into various forms of innovation and observable configurations in films are observable and document the specific technological fields in cinema, and innovations brought by young IT and digital companies.

Design/methodology/approach

– The paper is based on desk research, a review of literature, review of the technical journals, analysis of annual reports and meeting with experts and industry participants.

Findings

– It identifies in most cases the presence of information and communication technologies (ICT) companies, new middlemen of the digital age, that integrate in one or another way the core activity of the cinema industry. These companies (“specialized technological companies” with edge R & D) are playing the rather recent role of “new middlemen” liaising between the different layers of a transformed industrial environment described as the “new ICT ecosystem”.

Research limitations/implications

– The size of the sample (case studies) as the paper relies on some emblematic cases which come with some limits for any generalisation. Besides, most of the information is derived from company websites, complemented by trade press which clearly comes with some constraints in terms of accuracy.

Social implications

– The paper concludes delineating some potential policy interventions, and identifies the challenges ahead with a focus on the EU.

Originality/value

– Innovation is not so frequently dealt with in the studies of the cultural sectors. One very important issue is neglected both in the scientific literature and in the committed reports: the characteristic and the management of R & D in the creative industries, especially in the cultural sector. The paper shed some light on this issue.