bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Structure and Properties of an Erbium(III) Complex with Chiral Salen‐type Schiff Base Ligand
Authors: Sui Yan , Hu Rong‐Hua , Luo Zhi‐Gang , Lin Wen‐Hua , Liu Dong‐Sheng
Published: May 2015

A new type of ionic ferroelectric based on a chiral salen‐type Schiff base erbium(III) complex (ErL) was synthesized by the reaction of erbium nitrate with the ligand N,N′‐bis(3,5‐dichlorosalicylidene)‐(1S,2S)‐1,2‐cyclohexylenediamine (L). The structures of the ligand L and the complex ErL were determined by single‐crystal X‐ray diffraction. The results indicated that ErIII not only acts as central metal atom to coordinate with two Schiff base ligands, but also as Lewis acid catalyst to promote the partial decomposition of another salen‐type Schiff base ligand. The central ErIII atom adopts an octacoordinate square antiprismatic arrangement with Λ absolute configuration, coordinating with all nitrogen and oxygen atoms of two ligands due to the influence of the strong electron‐withdrawing group on the Schiff base ligand. The complex ErL exhibits good SHG and ferroelectric properties. The results provide a simple and effective approach to construct rare earth complexes coordinated with nitrogen and oxygen atoms of salen‐type Schiff base ligands with technologically important properties such as SHG activity and ferroelectricity.
Microporous Zinc(II) Metal‐Organic Framework with 6‐Connected pcu Topology: Synthesis, Structure, and Gas Adsorption Properties
Authors: Xing Guang'en , Liu Qifeng , Zhang Yan , Zhang Sufang , Dong Yanli
Published: May 2015

The zinc(II) complex [Zn(FA)(datrz)2]n (1) (H2FA = fumaric acid, Hdatrz = 3,5‐diamino‐1,2,4‐triazole) was synthesized by solvothermal reaction of H2FA, Hdatrz, and Zn(NO3)2. Single crystal X‐ray structure analysis revealed that compound 1 features a three‐dimensional (3D) porous framework, which represents a 6‐connected pcu topological network. Thermogravimetric analysis (TGA) indicates that compound 1 has high thermal stability. The permanent porosity of 1 was investigated by the adsorption of N2 and CO2. The amino groups of 1 enable high CO2 adsorption capacity.
Maximizing the identification of QTL for pre-harvest sprouting resistance using seed dormancy measures in a white-grained hexaploid wheat population
Authors: Kumar Sachin , Knox Ron E. , Clarke Fran R. , Pozniak Curtis J. , DePauw Ron M. , Cuthbert Richard D. , Fox Stephen
Published: May 2015

Pre-harvest sprouting in spring wheat causes significant financial loss to growers throughout the world and sprouting damage can be reduced by growing resistant genotypes. Several genetic factors, especially those related to seed dormancy, are involved in the control of pre-harvest sprouting resistance. The objective of this study was to identify quantitative trait loci (QTL) influencing pre-harvest sprouting resistance from multiple measures of dormancy at multiple germination intervals on seed harvested across multiple environments. A doubled haploid mapping population of 91 individuals derived from a cross of two Canadian white-seeded spring wheat genotypes, SC8021-V2 (pre-harvest sprouting resistant) and AC Karma (moderately susceptible to pre-harvest sprouting) was used for QTL mapping. Daily germination counts were analysed using germination index, germination resistance and percent germination at intervals of 3, 5, 7, 10, 14 and 21 days from spike samples collected from six field and one greenhouse environments in Saskatchewan, Canada. Continuous frequency distributions at certain measure-durations indicated genetic complexity of dormancy segregation in the SC8021-V2/AC Karma cross. Composite interval mapping detected significant (p ≤ 0.05) QTL associated with resistance to pre-harvest sprouting on all 21 wheat chromosomes. Of the 26 total QTL, six were novel and the rest were detected either at the same marker or overlapping a marker interval reported in other studies. QTL expressed consistently for germination index, germination resistance and percent germination at different germination durations on chromosomes 2B, 4A, 5D and 6D. QTL identified on homoeologous chromosomes 4A, 4B and 4D with chromosome specific molecular variants of SSR markerwmc617suggest a conserved region for controlling dormancy on group four. The majority of QTL mapped in regions known to contain factors affecting different components of pre-harvest sprouting resistance like seed dormancy, seed coat colour, ABA responsiveness and alpha-amylase activity. This study demonstrated that using multiple measures of seed dormancy at multiple intervals of germination enhanced identification of QTL affecting dormancy in white-seeded hexaploid wheat.
Teaching in the clinical workplace: looking beyond the power of ‘the one’
Authors: Stalmeijer Renée E.
Published: May 2015

None
Structural impact of complete CpG methylation within target DNA on specific complex formation of the inducible transcription factor Egr‐1
Authors: Zandarashvili Levani , White Mark A. , Esadze Alexandre , Iwahara Junji
Published: May 2015

The inducible transcription factor Egr‐1 binds specifically to 9‐bp target sequences containing two CpG sites that can potentially be methylated at four cytosine bases. Although it appears that complete CpG methylation would make an unfavorable steric clash in the previous crystal structures of the complexes with unmethylated or partially methylated DNA, our affinity data suggest that DNA recognition by Egr‐1 is insensitive to CpG methylation. We have determined, at a 1.4‐Å resolution, the crystal structure of the Egr‐1 zinc‐finger complex with completely methylated target DNA. Structural comparison of the three different methylation states reveals why Egr‐1 can recognize the target sequences regardless of CpG methylation.
Distinct effects of perinatal exposure to fluoxetine or methylmercury on parvalbumin and perineuronal nets, the markers of critical periods in brain development
Authors: Umemori Juzoh , Winkel Frederike , Castrén Eero , Karpova Nina N.
Published: May 2015

The in utero exposure to common chemical stressors, environmental pollutant methylmercury and antidepressant fluoxetine, results in behavioral impairments persistent into adulthood. Modulation of critical periods in brain development may alter proper network formation and lastingly impair brain function. To investigate whether early‐life stressors can modulate critical periods, we analyzed the development of parvalbumin (PV) and perineuronal nets (PNNs) in the dentate gyrus and CA1 area of the hippocampus and the basolateral amygdala in mice perinatally exposed to either fluoxetine or methylmercury. The number of PV and PNN neurons, and PV intensity, were analyzed by fluorescent immunohistochemistry at the postnatal ages P17 (ongoing critical period) and P24 (closing critical period). The exposure to fluoxetine did not affect the number of PV cells and PV intensity but decreased PNN formation around the cells at P17 and P24 in all tissues. In contrast, perinatal methylmercury inhibited the development of PV interneurons and PV expression at P17 only, but at P24 these parameters were restored. Methylmercury strongly increased PNN formation from P17 to P24 in the amygdala only. We suggest that perinatal fluoxetine and methylmercury might delay the closure and the onset, respectively, of the critical periods in the amygdala and hippocampus.
“The Real Thing”: Election Campaigns and The Question of Authenticity in American Film and Television
Authors: FRAME GREGORY
Published: May 2015

This article examines the concept of authenticity in American politics through its construction and representation in fictional election campaigns in film and television. This article will positThe Candidate(1972),Tanner '88(1988),Wag the Dog(1997) andThe West Wing(1999–2006) as crucial sites of popular cultural critique of this aspect of the electoral process:The Candidateas a damning critique of television's influence,Tanner '88as a satirical take on campaign films in the Reagan era,Wag the Dogas a savage indictment of spin-doctoring during Clinton's presidency, andThe West Wing's attempt to rescue the process through the construction of an “authentic” political candidate. This involves close textual analysis of the four examples identified, examining the contrasting visual styles, strategies and tones. The textual discussions will not take place in isolation, however: this article will chart the simultaneous developments in real-world electoral politics, with particular focus on the influence of the media in the election campaigns contemporaneous with the fictional examples discussed. The article charts a shift in the representation of political authenticity, from a cynical attitude towards its possibility in the 1970s, to an uncomplicated reversion to traditional markers of this elusive concept in the 2000s.
Overview of laser-driven generation of electron–positron beams
Authors: Sarri G. , Dieckmann M. E. , Kourakis I. , Di Piazza A. , Reville B. , Keitel C. H. , Zepf M.
Published: May 2015

Electron–positron (e–p) plasmas are widely thought to be emitted, in the form of ultra-relativistic winds or collimated jets, by some of the most energetic or powerful objects in the Universe, such as black-holes, pulsars, and quasars. These phenomena represent an unmatched astrophysical laboratory to test physics at its limit and, given their immense distance from Earth (some even farther than several billion light years), they also provide a unique window on the very early stages of our Universe. However, due to such gigantic distances, their properties are only inferred from the indirect interpretation of their radiative signatures and from matching numerical models: their generation mechanism and dynamics still pose complicated enigmas to the scientific community. Small-scale reproductions in the laboratory would represent a fundamental step towards a deeper understanding of this exotic state of matter. Here we present recent experimental results concerning the laser-driven production of ultra-relativistic e–p beams. In particular, we focus on the possibility of generating beams that present charge neutrality and that allow for collective effects in their dynamics, necessary ingredients for the testing pair-plasma physics in the laboratory. A brief discussion of the analytical and numerical modelling of the dynamics of these plasmas is also presented in order to provide a summary of the novel plasma physics that can be accessed with these objects. Finally, general considerations on the scalability of laboratory plasmas up to astrophysical scenarios are given.
Melaspilea demissa(Tuck.) Zahlbr. (lichenized Ascomycota) in eastern North America with a key to North American species ofMelaspileas. lat.
Authors: Perlmutter Gary B. , Tucker Shirley C. , Rivas Plata Eimy , Clerc Philippe , Lücking Robert
Published: May 2015

Recently collected specimens of the crustose lichenMelaspilea demissafrom south-eastern USA have been compared with those ofMelaspileaspp. previously determined from North America. A review of both the historical and contemporary treatments of this species is provided. A lectotype was selected from the type collection ofM. demissain FH and is here proposed as it best matches incomplete citations in the original treatment. We also discuss the nomenclatural and taxonomic status of the nameOpegrapha cymbiformisvar.deformis(considered a synonym ofM. gibberulosa). North American specimens ofM. gibberulosawere found to be misidentifications, as were specimens attributed toM. lentiginosula,M. mesophlebiaandM. octomera. We therefore recommend that these species be removed from the North American lichen checklist. We also present a key to North AmericanMelaspilea.
Changes in functional traits of the terricolous lichen Peltigera aphthosa across a retrogressive boreal forest chronosequence
Authors: Asplund Johan , Wardle David A.
Published: May 2015

Changes in the functional traits of the terricolous lichen Peltigera aphthosa with declining soil fertility during ecosystem retrogression were investigated. A well-documented retrogressive chronosequence of 28 forested islands in northern Sweden that differ greatly in fire history and which spans 5000 years was used. The abundance of cephalodia increased, indicative of higher N2-fixation rates resulting from lower N availability. Thallus δ13C values increased with ageing soils, in line with declining δ13C values of the humus substratum along this gradient. However, δ13C values were also driven by variation in factors that were at least partly independent of soil ageing. As such, δ13C values were mostly related to specific thallus mass (STM), possibly because a higher STM gives a thicker cortical layer and thus greater resistance to CO2 diffusion, leading to higher δ13C values. STM and other measured traits (i.e. thallus N, P, secondary compounds and water-holding capacity) were unresponsive to the gradient, despite these traits being very responsive to the same gradient in epiphytic lichen species.
Development and characterization of fungal specific microsatellite markers in the lichenLobarina scrobiculata(Lobariaceae, Ascomycota)
Authors: Prieto Maria , Romera Lidia , Merinero Sonia , Aragón Gregorio , Martínez Isabel
Published: May 2015

Lobarina scrobiculata(better known asLobaria scrobiculata) is a widespread lichen, threatened and Red-Listed in various European countries. Microsatellite markers for the mycobiont ofL. scrobiculatawere developed in order to investigate its genetic diversity in the Iberian Peninsula and Europe and to design effective conservation strategies. A total of 7 polymorphic markers were isolated and characterized. These microsatellites were tested in natural populations found in the Iberian Peninsula. The number of observed alleles ranged from 3 to 8, and the Nei's unbiased gene diversity from 0·26 to 0·59. These microsatellite markers are the first to be developed forL. scrobiculataand they will be useful for population studies and for the assessment of the conservation status of this species.
Autonomy in second language phonology: Choice vs. limits
Authors: Moyer Alene
Published: May 2015

Learning a new sound system poses challenges of a social, psychological, and cognitive nature, but the learner's decisions are key to ultimate attainment. This presentation focuses on two essential concepts:choice, or how one wants to sound in the target language; andlimits, or various challenges to one's goals vis-à-vis accent. Qualitative and quantitative data underscore the relevance of autonomy as a guiding principle from which to explore related constructs such as self-determination, motivation, decision-making and self-concept. I also review several prominentlimitson phonological attainment to counterbalance and contextualize the aspect ofchoice. Suggestions are given for both teaching and research that prioritize autonomy with reference to a complexity perspective.
Optimized laser vacuum acceleration by static magnetic field
Authors: Lin H. , Liu C. P. , Wang C. , Shen B. F.
Published: May 2015

Laser vacuum acceleration can be optimized significantly by applying a static magnetic field which is along the direction of laser magnetic field. This setup can cause a charged particle to be of a periodic, oscillatory-rising velocity, and significantly high kinetic energy. Moreover, the contribution from the motion vertical to accelerating electric field is fully taken into account and is found to be essential to efficient acceleration.
A NEW CHARACTERIZATION OF THE NORMAL DISTRIBUTION AND TEST FOR NORMALITY
Authors: Bera Anil K. , Galvao Antonio F. , Wang Liang , Xiao Zhijie
Published: May 2015

We study the asymptotic covariance function of the sample mean and quantile, and derive a new and surprising characterization of the normal distribution: the asymptotic covariance between the sample mean and quantile is constant across all quantiles,if and only ifthe underlying distribution is normal. This is a powerful result and facilitates statistical inference. Utilizing this result, we develop a new omnibus test for normality based on the quantile-mean covariance process. Compared to existing normality tests, the proposed testing procedure has several important attractive features. Monte Carlo evidence shows that the proposed test possesses good finite sample properties. In addition to the formal test, we suggest a graphical procedure that is easy to implement and visualize in practice. Finally, we illustrate the use of the suggested techniques with an application to stock return datasets.
Identifying economic crises: insights from history
Authors: De Scheemaekere Xavier , Oosterlinck Kim , Szafarz Ariane
Published: May 2015

Economists have been blamed for their inability to forecast and address crises. This article attributes this inability to intertwined factors: the lack of a coherent definition of crises, the reference-class problem, the lack of imagination regarding the nature of future crises and sample-selection biases. Specifically, economists tend to adapt their views on crises to recent episodes, and omit averted and potential crises. Threshold-based definitions of crises run the risk of being ad hoc. Using historical examples, this article highlights some epistemological shortcomings of the current approach.
Local adaptation constrains the distribution potential of heat-tolerant Symbiodinium from the Persian/Arabian Gulf
Authors: D’Angelo Cecilia , Hume Benjamin C C , Burt John , Smith Edward G , Achterberg Eric P , Wiedenmann Jörg
Published: May 2015

The symbiotic association of corals and unicellular algae of the genus Symbiodinium in the southern Persian/Arabian Gulf (PAG) display an exceptional heat tolerance, enduring summer peak temperatures of up to 36 °C. As yet, it is not clear whether this resilience is related to the presence of specific symbiont types that are exclusively found in this region. Therefore, we used molecular markers to identify the symbiotic algae of three Porites species along >1000 km of coastline in the PAG and the Gulf of Oman and found that a recently described species, Symbiodinium thermophilum, is integral to coral survival in the southern PAG, the world’s hottest sea. Despite the geographic isolation of the PAG, we discovered that representatives of the S. thermophilum group can also be found in the adjacent Gulf of Oman providing a potential source of thermotolerant symbionts that might facilitate the adaptation of Indian Ocean populations to the higher water temperatures expected for the future. However, corals from the PAG associated with S. thermophilum show strong local adaptation not only to high temperatures but also to the exceptionally high salinity of their habitat. We show that their superior heat tolerance can be lost when these corals are exposed to reduced salinity levels common for oceanic environments elsewhere. Consequently, the salinity prevailing in most reefs outside the PAG might represent a distribution barrier for extreme temperature-tolerant coral/Symbiodinium associations from the PAG.
Intestinal intraepithelial lymphocyte activation promotes innate antiviral resistance
Authors: Swamy Mahima , Abeler-Dörner Lucie , Chettle James , Mahlakõiv Tanel , Goubau Delphine , Chakravarty Probir , Ramsay George , Reis e Sousa Caetano , Staeheli Peter , Blacklaws Barbara A. , Heeney Jonathan L. , Hayday Adrian C.
Published: May 2015

Unrelenting environmental challenges to the gut epithelium place particular demands on the local immune system. In this context, intestinal intraepithelial lymphocytes (IEL) compose a large, highly conserved T cell compartment, hypothesized to provide a first line of defence via cytolysis of dysregulated intestinal epithelial cells (IEC) and cytokine-mediated re-growth of healthy IEC. Here we show that one of the most conspicuous impacts of activated IEL on IEC is the functional upregulation of antiviral interferon (IFN)-responsive genes, mediated by the collective actions of IFNs with other cytokines. Indeed, IEL activation in vivo rapidly provoked type I/III IFN receptor-dependent upregulation of IFN-responsive genes in the villus epithelium. Consistent with this, activated IEL mediators protected cells against virus infection in vitro, and pre-activation of IEL in vivo profoundly limited norovirus infection. Hence, intraepithelial T cell activation offers an overt means to promote the innate antiviral potential of the intestinal epithelium.
Endothelial Caveolin-1 regulates the radiation response of epithelial prostate tumors
Authors: Klein D , Schmitz T , Verhelst V , Panic A , Schenck M , Reis H , Drab M , Sak A , Herskind C , Maier P , Jendrossek V
Published: May 2015

The membrane protein caveolin-1 (Cav1) recently emerged as a novel oncogene involved in prostate cancer progression with opposed regulation in epithelial tumor cells and the tumor stroma. Here we examined the role of stromal Cav1 for growth and radiation response of MPR31-4 prostate cancer xenograft tumors using Cav1-deficient C57Bl/6 mice. Syngeneic MPR31-4 tumors grew faster when implanted into Cav1-deficient mice. Increased tumor growth on Cav1-deficient mice was linked to decreased integration of smooth muscle cells into the wall of newly formed blood vessels and thus with a less stabilized vessel phenotype compared with tumors from Cav1 wild-type animals. However, tumor growth delay of MPR31-4 tumors grown on Cav1 knockout mice to a single high-dose irradiation with 20 Gray was more pronounced compared with tumors grown on wild-type mice. Increased radiation-induced tumor growth delay in Cav1-deficient mice was associated with an increased endothelial cell apoptosis. In vitro studies using cultured endothelial cells (ECs) confirmed that the loss of Cav1 expression increases sensitivity of ECs to radiation-induced apoptosis and reduces their clonogenic survival after irradiation. Immunohistochemical analysis of human tissue specimen further revealed that although Cav1 expression is mostly reduced in the tumor stroma of advanced and metastatic prostate cancer, the vascular compartment still expresses high levels of Cav1. In conclusion, the radiation response of MPR31-4 prostate tumors is critically regulated by Cav1 expression in the tumor vasculature. Thus, Cav1 might be a promising therapeutic target for combinatorial therapies to counteract radiation resistance of prostate cancer at the level of the tumor vasculature.
Adaptive power-controllable orbital angular momentum (OAM) multicasting
Authors: Li Shuhui , Wang Jian
Published: May 2015

We report feedback-assisted adaptive multicasting from a single Gaussian mode to multiple orbital angular momentum (OAM) modes using a single phase-only spatial light modulator loaded with a complex phase pattern. By designing and optimizing the complex phase pattern through the adaptive correction of feedback coefficients, the power of each multicast OAM channel can be arbitrarily controlled. We experimentally demonstrate power-controllable multicasting from a single Gaussian mode to two and six OAM modes with different target power distributions. Equalized power multicasting, “up-down” power multicasting and “ladder” power multicasting are realized in the experiment. The difference between measured power distributions and target power distributions is assessed to be less than 1 dB. Moreover, we demonstrate data-carrying OAM multicasting by employing orthogonal frequency-division multiplexing 64-ary quadrature amplitude modulation (OFDM 64-QAM) signal. The measured bit-error rate curves and observed optical signal-to-noise ratio penalties show favorable operation performance of the proposed adaptive power-controllable OAM multicasting.
Low-dose add-on memantine treatment may improve cognitive performance and self-reported health conditions in opioid-dependent patients undergoing methadone-maintenance-therapy
Authors: Chang Yun-Hsuan , Chen Shiou-Lan , Lee Sheng-Yu , Chen Po See , Wang Tzu-Yun , Lee I. Hui , Chen Kao Chin , Yang Yen Kuang , Hong Jau-Shyong , Lu Ru-Band
Published: May 2015

An important interaction between opioid and dopamine systems has been indicated and using opioids may negatively affect cognitive functioning. Memantine, a medication for Alzheimer's disease, increasingly is being used for several disorders and maybe important for cognitive improvement. Opioid-dependent patients undergoing methadone-maintenance-therapy (MMT) and healthy controls (HCs) were recruited. Patients randomly assigned to the experimental (5 mg/day memantine (MMT+M) or placebo (MMT+P) group: 57 in MMT+M, 77 in MMT+P. Those completed the cognitive tasks at the baseline and after the 12-week treatment were analyzed. Thirty-seven age- and gender-matched HCs and 42 MMT+P and 39 MMT+M patients were compared. The dropout rates were 49.4% in the MMT+P and 26.3% in the MMT+M. Both patient groups' cognitive performances were significantly worse than that of the HCs. After the treatment, both patient groups showed improved cognitive performance. We also found an interaction between the patient groups and time which indicated that the MMT+M group's post-treatment improvement was better than that of the MMT+P group. Memantine, previously reported as neuroprotective may attenuate chronic opioid-dependence-induced cognitive decline. Using such low dose of memantine as adjuvant treatment for improving cognitive performance in opioid dependents; the dose of memantine might be a worthy topic in future studies.
Robo1/2 regulate follicle atresia through manipulating granulosa cell apoptosis in mice
Authors: Li Jiangchao , Ye Yuxiang , Zhang Renli , Zhang Lili , Hu Xiwen , Han Dong , Chen Jiayuan , He Xiaodong , Wang Guang , Yang Xuesong , Wang Lijing
Published: May 2015

Secreted Slit proteins and their Roundabout (Robo) receptors act as a repulsive cue to preventaxons from migrating to inappropriate locations during the development of the nervous system. Slit/Robo has also been implicated in reproductive system development, but the molecular mechanism of the Slit/Robo pathway in the reproductive system remains poorly understood. Using a transgenic mouse model, we investigated the function of the Slit/Robo pathway on ovarian follicle development and atresia. We first demonstrated that more offspring were born to mice with a partial knockout of the Robo1/2 genes in mice. We next showed that Robo1 and Robo2 are strongly expressed in ovarian granulosacells. Apoptosis in granulosa cells was reduced when Robo1/2 were partially knocked out and this observation was further verified by in vitro Robo1/2 knockout experiments in mouse and human granulosa cells. We also found that ovarian angiogenesis wasenhanced by a partial lack of Robo1/2 genes. In summary, our data suggest that the Slit/Robo pathway can impact follicle development and atresia by influencinggranulosa cell apoptosis.
MICCA: a complete and accurate software for taxonomic profiling of metagenomic data
Authors: Albanese Davide , Fontana Paolo , De Filippo Carlotta , Cavalieri Duccio , Donati Claudio
Published: May 2015

The introduction of high throughput sequencing technologies has triggered an increase of the number of studies in which the microbiota of environmental and human samples is characterized through the sequencing of selected marker genes. While experimental protocols have undergone a process of standardization that makes them accessible to a large community of scientist, standard and robust data analysis pipelines are still lacking. Here we introduce MICCA, a software pipeline for the processing of amplicon metagenomic datasets that efficiently combines quality filtering, clustering of Operational Taxonomic Units (OTUs), taxonomy assignment and phylogenetic tree inference. MICCA provides accurate results reaching a good compromise among modularity and usability. Moreover, we introduce a de-novo clustering algorithm specifically designed for the inference of Operational Taxonomic Units (OTUs). Tests on real and synthetic datasets shows that thanks to the optimized reads filtering process and to the new clustering algorithm, MICCA provides estimates of the number of OTUs and of other common ecological indices that are more accurate and robust than currently available pipelines. Analysis of public metagenomic datasets shows that the higher consistency of results improves our understanding of the structure of environmental and human associated microbial communities. MICCA is an open source project.
Expression and purification of a single-chain Type IV restriction enzyme Eco94GmrSD anddetermination of its substrate preference
Authors: He Xinyi , Hull Victoria , Thomas Julie A. , Fu Xiaoqing , Gidwani Sonal , Gupta Yogesh K. , Black Lindsay W. , Xu Shuang-yong
Published: May 2015

The first reported Type IV restriction endonuclease (REase) GmrSD consists of GmrSand GmrD subunits. In most bacteria, however, the gmrS and gmrD genesare fused together to encode a single-chain protein. The fused coding sequence forECSTEC94C_1402 from E. coli strain STEC_94C was expressed in T7 Express. Theprotein designated as Eco94GmrSD displays modification-dependent ATP-stimulatedREase activity on T4 DNA with glucosyl-5-hydroxymethyl-cytosines (glc-5hmC) and T4gtDNA with 5-hydroxymethyl-cytosines (5hmC). A C-terminal 6xHis-tagged protein waspurified by two-column chromatography. The enzyme is active in Mg2+and Mn2+ buffer. It prefers to cleave large glc-5hmC- or5hmC-modified DNA. In phage restriction assays, Eco94GmrSD weakly restricted T4 andT4gt, whereas T4 IPI*-deficient phage (Δip1) were restricted morethan 106-fold, consistent with IPI* protection of E. coliDH10B from lethal expression of the closely homologous E. coli CT596 GmrSD.Eco94GmrSD is proposed to belong to the His-Asn-His (HNH)-nuclease family by theidentification of a putative C-terminal REase catalytic site D507-H508-N522.Supporting this, GmrSD variants D507A, H508A and N522A displayed no endonucleaseactivity. The presence of a large number of fused GmrSD homologs suggests that GmrSDis an effective phage exclusion protein that provides a mechanism to thwart T-evenphage infection.
Effect of divalent Ba cation substitution with Sr on coupled ‘multiglass’ state in the magnetoelectric multiferroic compound Ba3NbFe3Si2O14
Authors: Rathore Satyapal Singh , Vitta Satish
Published: May 2015

(Ba/Sr)3NbFe3Si2O14 is a magneto-electric multiferroic with an incommensurate antiferromagnetic spiral magnetic structure which induces electric polarization at 26 K. Structural studies show that both the compounds have similar crystal structure down to 6 K. They exhibit a transition, TN at 26 K and 25 K respectively, as indicated by heat capacity and magnetization, into an antiferromagnetic state. Although Ba and Sr are isovalent, they exhibit very different static and dynamic magnetic behaviors. The Ba-compound exhibits a glassy behavior with critical slowing dynamics with a freezing temperature of ~35 K and a critical exponent of 3.9, a value close to the 3-D Ising model above TN, in addition to the invariant transition into an antiferromagnetic state. The Sr-compound however does not exhibit any dispersive behavior except for the invariant transition at TN. The dielectric constant reflects magnetic behavior of the two compounds: the Ba-compound has two distinct dispersive peaks while the Sr-compound has a single dispersive peak. Thus the compounds exhibit coupled ‘multiglass’ behavior. The difference in magnetic properties between the two compounds is found to be due to modifications to super exchange path angle and length as well as anti-site defects which stabilize either ferromagnetic or antiferromagnetic interactions.
Scaling for quantum tunneling current in nano- and subnano-scale plasmonic junctions
Authors: Zhang Peng
Published: May 2015

When two conductors are separated by a sufficiently thin insulator, electrical current can flow between them by quantum tunneling. This paper presents a self-consistent model of tunneling current in a nano- and subnano-meter metal-insulator-metal plasmonic junction, by including the effects of space charge and exchange correlation potential. It is found that the J-V curve of the junction may be divided into three regimes: direct tunneling, field emission and space-charge-limited regime. In general, the space charge inside the insulator reduces current transfer across the junction, whereas the exchange-correlation potential promotes current transfer. It is shown that these effects may modify the current density by orders of magnitude from the widely used Simmons’ formula, which is only accurate for a limited parameter space (insulator thickness > 1 nm and barrier height > 3 eV) in the direct tunneling regime. The proposed self-consistent model may provide a more accurate evaluation of the tunneling current in the other regimes. The effects of anode emission and material properties (i.e. work function of the electrodes, electron affinity and permittivity of the insulator) are examined in detail in various regimes. Our simple model and the general scaling for tunneling current may provide insights to new regimes of quantum plasmonics.
How does public opinion become extreme?
Authors: Ramos Marlon , Shao Jia , Reis Saulo D. S. , Anteneodo Celia , Andrade José S. , Havlin Shlomo , Makse Hernán A.
Published: May 2015

We investigate the emergence of extreme opinion trends in society by employing statistical physics modeling and analysis on polls that inquire about a wide range of issues such as religion, economics, politics, abortion, extramarital sex, books, movies and electoral vote. The surveys lay out a clear indicator of the rise of extreme views. The precursor is a nonlinear relation between the fraction of individuals holding a certain extreme view and the fraction of individuals that includes also moderates, e.g., in politics, those who are “very conservative” versus “moderate to very conservative” ones. We propose an activation model of opinion dynamics with interaction rules based on the existence of individual “stubbornness” that mimics empirical observations. According to our modeling, the onset of nonlinearity can be associated to an abrupt bootstrap-percolation transition with cascades of extreme views through society. Therefore, it represents an early-warning signal to forecast the transition from moderate to extreme views. Moreover, by means of a phase diagram we can classify societies according to the percolative regime they belong to, in terms of critical fractions of extremists and people’s ties.
Motion and gravity effects in the precision of quantum clocks
Authors: Lindkvist Joel , Sabín Carlos , Johansson Göran , Fuentes Ivette
Published: May 2015

We show that motion and gravity affect the precision of quantum clocks. We consider a localised quantum field as a fundamental model of a quantum clock moving in spacetime and show that its state is modified due to changes in acceleration. By computing the quantum Fisher information we determine how relativistic motion modifies the ultimate bound in the precision of the measurement of time. While in the absence of motion the squeezed vacuum is the ideal state for time estimation, we find that it is highly sensitive to the motion-induced degradation of the quantum Fisher information. We show that coherent states are generally more resilient to this degradation and that in the case of very low initial number of photons, the optimal precision can be even increased by motion. These results can be tested with current technology by using superconducting resonators with tunable boundary conditions.
Low-dose memantine attenuated methadone dose in opioid-dependent patients: a 12-week double-blind randomized controlled trial
Authors: Lee Sheng-Yu , Chen Shiou-Lan , Chang Yun-Hsuan , Chen Po See , Huang San-Yuan , Tzeng Nian-Sheng , Wang Liang-Jen , Lee I Hui , Wang Tzu-Yun , Chen Kao Chin , Yang Yen Kuang , Hong Jau-Shyong , Lu Ru-Band
Published: May 2015

Low-dose memantine might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. We investigated whether add-on memantine reduced cytokine levels and benefitted patients with opioid dependence undergoing methadone maintenance therapy (MMT) in a randomized, double-blind, controlled 12-week study. Patients were randomly assigned to a group: Memantine (5 mg/day) (n = 53) or Placebo (n = 75). The methadone dose required and retention in treatment were monitored. Plasma tumor necrosis factor (TNF)-α, C-reactive protein (CRP), interleukin (IL)-6, IL-8, transforming growth factor (TGF)-β1 and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8 and 12. General linear mixed models were used to examine therapeutic effect. After 12 weeks, Memantine-group required a somewhat lower methadone dose than did Placebo-group (P = 0.039). They also had significantly lower plasma TNF-α and significantly higher TGF-β1 levels. We provide evidence of the benefit of add-on memantine in opioid dependent patients undergoing MMT.
Multiplexed Millimeter Wave Communication with Dual Orbital Angular Momentum (OAM) Mode Antennas
Authors: Hui Xiaonan , Zheng Shilie , Chen Yiling , Hu Yiping , Jin Xiaofeng , Chi Hao , Zhang Xianmin
Published: May 2015

Communications using the orbital angular momentum (OAM) of radio waves have attracted much attention in recent years. In this paper, a novel millimeter-wave dual OAM mode antenna is cleverly designed, using which a 60 GHz wireless communication link with two separate OAM channels is experimentally demonstrated. The main body of the dual OAM antenna is a traveling-wave ring resonator using two feeding ports fed by a 90° hybrid coupler. A parabolic reflector is used to focus the beams. All the antenna components are fabricated by 3D printing technique and the electro-less copper plating surface treatment process. The performances of the antenna, such as S-parameters, near-fields, directivity and isolation between the two OAM modes are measured. Experimental results show that this antenna can radiate two coaxially propagating OAM modes beams simultaneously. The multiplexing and de-multiplexing are easily realized in the antennas themselves. The two OAM mode channels have good isolation of more than 20 dB, thus ensuring the reliable transmission links at the same time.
Analysis of the genetic basis of periodic fever with aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome
Authors: Gioia Silvio Alessandro Di , Bedoni Nicola , von Scheven-Gête Annette , Vanoni Federica , Superti-Furga Andrea , Hofer Michaël , Rivolta Carlo
Published: May 2015

PFAPA syndrome is the most common autoinflammatory syndrome in children from Western countries. In spite of its strong familial clustering, its genetic basis and inheritance pattern are still unknown. We performed a comprehensive genetic study on 68 individuals from 14 families. Linkage analysis suggested a susceptibility locus on chromosome 8, but direct molecular sequencing did not support this initial statistical finding. Exome sequencing revealed the absence of any gene that was mutated in all patients. Exhaustive screening of genes involved in other autoinflammatory syndromes or encoding components of the human inflammasome showed no DNA variants that could be linked to PFAPA molecular pathology. Among these, the previously-reported missense mutation V198M in the NLRP3 gene was clearly shown not to co-segregate with PFAPA. Our results on this relatively large cohort indicate that PFAPA syndrome is unlikely to be a monogenic condition. Moreover, none of the several genes known to be involved in inflammation or in autoinflammatory disorders seem to be relevant, alone, to its etiology, suggesting that PFAPA results from oligogenic or complex inheritance of variants in multiple disease genes and/or non-genetic factors.
The pluripotency factor NANOG promotes the formation of squamous cell carcinomas
Authors: Palla Adelaida R. , Piazzolla Daniela , Alcazar Noelia , Cañamero Marta , Graña Osvaldo , Gómez-López Gonzalo , Dominguez Orlando , Dueñas Marta , Paramio Jesús M. , Serrano Manuel
Published: May 2015

NANOG is a key pluripotency factor in embryonic stem cells that is frequently expressed in squamous cell carcinomas (SCCs). However, a direct link between NANOG and SCCs remains to be established. Here, we show that inducible overexpression of NANOG in mouse skin epithelia favours the malignant conversion of skin papillomas induced by chemical carcinogenesis, leading to increased SCC formation. Gene expression analyses in pre-malignant skin indicate that NANOG induces genes associated to epithelial-mesenchymal transition (EMT). Some of these genes are directly activated by NANOG, including EMT-associated genes Zeb1, Zeb2, Twist1, Prrx1 and miR-21. Finally, endogenous NANOG binds to the promoters of theses genes in human SCC cells and, moreover, NANOG induces EMT features in primary keratinocytes. These results provide in vivo evidence for the oncogenic role of NANOG in squamous cell carcinomas.
Regulation of Immunoproteasome Function in the Lung
Authors: Keller Ilona E. , Vosyka Oliver , Takenaka Shinji , Kloß Alexander , Dahlmann Burkhardt , Willems Lianne I. , Verdoes Martijn , Overkleeft Hermen S. , Marcos Elisabeth , Adnot Serge , Hauck Stefanie M. , Ruppert Clemens , Günther Andreas , Herold Susanne , Ohno Shinji , Adler Heiko , Eickelberg Oliver , Meiners Silke
Published: May 2015

Impaired immune function contributes to the development of chronic obstructive pulmonary disease (COPD). Disease progression is further exacerbated by pathogen infections due to impaired immune responses. Elimination of infected cells is achieved by cytotoxic CD8+  T cells that are activated by MHC I-mediated presentation of pathogen-derived antigenic peptides. The immunoproteasome, a specialized form of the proteasome, improves generation of antigenic peptides for MHC I presentation thereby facilitating anti-viral immune responses. However, immunoproteasome function in the lung has not been investigated in detail yet. In this study, we comprehensively characterized the function of immunoproteasomes in the human and murine lung. Parenchymal cells of the lung express low constitutive levels of immunoproteasomes, while they are highly and specifically expressed in alveolar macrophages. Immunoproteasome expression is not altered in whole lung tissue of COPD patients. Novel activity-based probes and native gel analysis revealed that immunoproteasome activities are specifically and rapidly induced by IFNγ treatment in respiratory cells in vitro and by virus infection of the lung in mice. Our results suggest that the lung is potentially capable of mounting an immunoproteasome-mediated efficient adaptive immune response to intracellular infections.
Genetic association study of circadian genes with seasonal pattern in bipolar disorders
Authors: Geoffroy Pierre Alexis , Lajnef Mohamed , Bellivier Frank , Jamain Stéphane , Gard Sébastien , Kahn Jean-Pierre , Henry Chantal , Leboyer Marion , Etain Bruno
Published: May 2015

About one fourth of patients with bipolar disorders (BD) have depressive episodes with a seasonal pattern (SP) coupled to a more severe disease. However, the underlying genetic influence on a SP in BD remains to be identified. We studied 269 BD Caucasian patients, with and without SP, recruited from university-affiliated psychiatric departments in France and performed a genetic single-marker analysis followed by a gene-based analysis on 349 single nucleotide polymorphisms (SNPs) spanning 21 circadian genes and 3 melatonin pathway genes. A SP in BD was nominally associated with 14 SNPs identified in 6 circadian genes:NPAS2,CRY2,ARNTL,ARNTL2,RORAandRORB. After correcting for multiple testing, using a false discovery rate approach, the associations remained significant for 5 SNPs inNPAS2(chromosome 2:100793045–100989719): rs6738097 (pc = 0.006), rs12622050 (pc = 0.006), rs2305159 (pc = 0.01), rs1542179 (pc = 0.01) and rs1562313 (pc = 0.02). The gene-based analysis of the 349 SNPs showed that rs6738097 (NPAS2) and rs1554338 (CRY2) were significantly associated with the SP phenotype (respective Empirical p-values of 0.0003 and 0.005). The associations remained significant for rs6738097 (NPAS2) after Bonferroni correction. The epistasis analysis between rs6738097 (NPAS2) and rs1554338 (CRY2) suggested an additive effect. Genetic variations inNPAS2might be a biomarker for a seasonal pattern in BD.
Chromodomain protein Tcd1 is required for macronuclear genome rearrangement and repair in Tetrahymena
Authors: Xu Jing , Yuan Yajing , Liang Aihua , Wang Wei
Published: May 2015

The survival of an organism’s progeny depends on the maintenance of its genome. Programmed DNA rearrangement and repair in Tetrahymena occur during the differentiation of the developing somatic macronuclear genome from the germ line micronuclear genome. Tetrahymena chromodomain protein (Tcd1) exhibited dynamic localization from the parental to the developing macronuclei. In the developing macronuclei, Tcd1 colocalized with Pdd1 and H3K9me3. Furthermore, Tcd1 colocalized with Pdd1 in the conjusome and “donut structure” of DNA elimination heterochromatin region. During the growth and conjugation stages, TCD1 knockout cells appeared normal and similar to wild-type strains. In addition, these knockout cells proceeded to the 2MAC-1MIC stage. However, the progeny of the TCD1 knockout cells did not grow upon return to SPP medium and eventually died. The deletion of the internal elimination sequence R element was partially disrupted in the developing new macronuclei. Gamma H2A staining showed that Tcd1 loss induced the accumulation of DNA double-strand breaks and the failure of genome repair. These results suggest that the chromodomain protein Tcd1 is required for the rearrangement and repair of new macronuclear genome in Tetrahymena.
Genomic analysis of a ginger pathogen Bacillus pumilus providing the understanding to the pathogenesis and the novel control strategy
Authors: Yuan Yihui , Gao Meiying
Published: May 2015

Bacillus pumilushas been widely identified as a pathogen of plant and human, while the genetic information is rarely available for pathogenicB. pumilusstrains.B. pumilusGR8 is a pathogen that causes ginger rhizome rot disease by invading ginger rhizome parenchymatous tissues, growing in the extracellular space and producing plant cell wall-degrading enzymes to destroy ginger cells. In this study, the genome of GR8 was sequenced and characterized. This genome was the third completely sequenced genome of theB. pumilusspecies and it exhibited high similarity to the genome of theB. pumilusstrain B6033. The genome of GR8 was 3.67 Mb in length and encoded 3,713 putative ORFs. Among these predicted proteins, numerous plant cell wall-degrading enzymes and several proteins associated with invading and adapting to the environment in the extracellular space of the ginger rhizome parenchymatous tissue were found. The GR8 genome contained only one restriction-modification system and no CRISPR/Cas system. The lack of phage-resistant system suggested that phages might be potential agents for the control of GR8. The genomic analysis of GR8 provided the understanding to the pathogenesis and the phage-control strategy of pathogenicB. pumilusstrains.
Heparin affinity purification of extracellular vesicles
Authors: Balaj Leonora , Atai Nadia A. , Chen Weilin , Mu Dakai , Tannous Bakhos A. , Breakefield Xandra O. , Skog Johan , Maguire Casey A.
Published: May 2015

Extracellular vesicles (EVs) are lipid membrane vesicles released by cells. They carry active biomolecules including DNA, RNA and protein which can be transferred to recipient cells. Isolation and purification of EVs from culture cell media and biofluids is still a major challenge. The most widely used isolation method is ultracentrifugation (UC) which requires expensive equipment and only partially purifies EVs. Previously we have shown that heparin blocks EV uptake in cells, supporting a direct EV-heparin interaction. Here we show that EVs can be purified from cell culture media and human plasma using ultrafiltration (UF) followed by heparin-affinity beads. UF/heparin-purified EVs from cell culture displayed the EV marker Alix, contained a diverse RNA profile, had lower levels of protein contamination and were functional at binding to and uptake into cells. RNA yield was similar for EVs isolated by UC. We were able to detect mRNAs in plasma samples with comparable levels to UC samples. In conclusion, we have discovered a simple, scalable and effective method to purify EVs taking advantage of their heparin affinity.