bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcription-Dependent Generation of a Specialized Chromatin Structure at the TCRβ Locus
Authors: Zacarías-Cabeza Joaquin , Belhocine Mohamed , Vanhille Laurent , Cauchy Pierre , Koch Frederic , Pekowska Aleksandra , Fenouil Romain , Bergon Aurélie , Gut Marta , Gut Ivo , Eick Dirk , Imbert Jean , Ferrier Pierre , Andrau Jean-Christophe , Spicuglia Salvatore 
Published: March 2015

Abstract
V(D)J recombination assembles Ag receptor genes during lymphocyte development. Enhancers at AR loci are known to control V(D)J recombination at associated alleles, in part by increasing chromatin accessibility of the locus, to allow the recombination machinery to gain access to its chromosomal substrates. However, whether there is a specific mechanism to induce chromatin accessibility at AR loci is still unclear. In this article, we highlight a specialized epigenetic marking characterized by high and extended H3K4me3 levels throughout the Dβ-Jβ-Cβ gene segments. We show that extended H3K4 trimethylation at the Tcrb locus depends on RNA polymerase II (Pol II)–mediated transcription. Furthermore, we found that the genomic regions encompassing the two DJCβ clusters are highly enriched for Ser5-phosphorylated Pol II and short-RNA transcripts, two hallmarks of transcription initiation and early transcription. Of interest, these features are shared with few other tissue-specific genes. We propose that the entire DJCβ regions behave as transcription “initiation” platforms, therefore linking a specialized mechanism of Pol II transcription with extended H3K4 trimethylation and highly accessible Dβ and Jβ gene segments.
FcμR Interacts and Cooperates with the B Cell Receptor To Promote B Cell Survival
Authors: Ouchida Rika , Lu Qing , Liu Jun , Li Yingqian , Chu Yiwei , Tsubata Takeshi , Wang Ji-Yang 
Published: March 2015

Abstract
The IgM FcR (FcμR) promotes B cell survival, but the molecular mechanism remains largely unknown. We show using FcμR−/− and wild-type mice that FcμR specifically enhanced B cell survival induced by BCR cross-linking with F(ab′)2-anti-IgM Abs while having no effect on survival when the B cells were activated by CD40 ligation or LPS stimulation. FcμR expression was markedly upregulated by anti-IgM stimulation, which may promote enhanced FcμR signaling in these cells. Immunofluorescence and confocal microscopy analyses demonstrated that FcμR colocalized with the BCR on the plasma membrane of primary B cells. Coimmunoprecipitation analysis further revealed that FcμR physically interacted with the BCR complex. Because NF-κB plays a prominent role in B cell survival, we analyzed whether FcμR was involved in BCR-triggered NF-κB activation. FcμR did not affect BCR-triggered IκBα phosphorylation characteristic of the canonical NF-κB activation pathway but promoted the production of the noncanonical NF-κB pathway component p52. Consistent with the elevated p52 levels, FcμR enhanced BCR-triggered expression of the antiapoptotic protein BCL-xL. Importantly, FcμR stimulation alone in the absence of BCR signaling had no effect on either IκBα phosphorylation or the expression of p52 and BCL-xL. Therefore, FcμR relied on the BCR signal to activate the noncanonical NF-κB pathway and enhance B cell survival. These results reveal a cross-talk downstream of FcμR and BCR signaling and provide mechanistic insight into FcμR-mediated enhancement of B cell survival after BCR stimulation.
A Novel Thymoma-Associated Immunodeficiency with Increased Naive T Cells and Reduced CD247 Expression
Authors: Christopoulos Petros , Dopfer Elaine P. , Malkovsky Miroslav , Esser Philipp R. , Schaefer Hans-Eckart , Marx Alexander , Kock Sylvia , Rupp Nicole , Lorenz Myriam R. , Schwarz Klaus , Harder Jan , Martin Stefan F. , Werner Martin , Bogdan Christian , Schamel Wolfgang W. A. , Fisch Paul 
Published: March 2015

Abstract
The mechanisms underlying thymoma-associated immunodeficiency are largely unknown, and the significance of increased blood γδ Τ cells often remains elusive. In this study we address these questions based on an index patient with thymoma, chronic visceral leishmaniasis, myasthenia gravis, and a marked increase of rare γδ T cell subsets in the peripheral blood. This patient showed cutaneous anergy, even though he had normal numbers of peripheral blood total lymphocytes as well as CD4+ and CD8+ T cells. Despite his chronic infection, analyses of immunophenotypes and spectratyping of his lymphocytes revealed an unusual accumulation of naive γδ and αβ T cells, suggesting a generalized T cell activation defect. Functional studies in vitro demonstrated substantially diminished IL-2 and IFN-γ production following TCR stimulation of his “untouched” naive CD4+ T cells. Biochemical analysis revealed that his γδ and αβ T cells carried an altered TCR complex with reduced amounts of the ζ-chain (CD247). No mutations were found in the CD247 gene that encodes the homodimeric ζ protein. The diminished presence of CD247 and increased numbers of γδ T cells were also observed in thymocyte populations obtained from three other thymoma patients. Thus, our findings describe a novel type of a clinically relevant acquired T cell immunodeficiency in thymoma patients that is distinct from Good’s syndrome. Its characteristics are an accumulation of CD247-deficient, hyporresponsive naive γδ and αβ T cells and an increased susceptibility to infections.
Geometric Invariants of Cuspidal Edges
Authors: de Fátima Martins Luciana , Saji Kentaro 
Published: March 2015

AbstractWe give a normal form of the cuspidal edge that uses only diffeomorphisms on the source
and isometries on the target. Using this normal form, we study differential geometric invariants of
cuspidal edges that determine them up to order three. We also clarify relations between these invariants.
A Multilevel Method for the Solution of Time Dependent Optimal Transport
Authors: Haber Eldad , Horesh Raya 
Published: March 2015

AbstractIn this paper we present a new computationally efficient numerical scheme for the minimizing flow for the computation of the optimal L2 mass transport mapping using the fluid approach. We review the method and discuss its numerical properties. We then derive a new scaleable, efficient discretization and a solution technique for the problem and show that the problem is equivalent to a mixed form formulation of a nonlinear fluid flow in porous media. We demonstrate the effectiveness of our approach using a number of numerical experiments.
Les carences de la traduction littéraire au Canada : des bibliographies et des traditions
Authors: Lane-Mercier Gillian 
Published: March 2015

L’objectif de cet article est double. Dans un premier temps, il vise à mettre au jour deux carences de la traduction littéraire au Canada. La première est d’ordre empirique : il n’existe aucun répertoire complet des oeuvres littéraires canadiennes traduites dans les deux langues officielles. La deuxième est d’ordre théorique : si, en 1977, Philip Stratford a pu constater l’absence d’une tradition de traduction littéraire au Canada, plus de trente ans plus tard, tout porte à croire que la situation a changé. Or, non seulement il n’existe aucune étude d’envergure qui remet en question le constat de Stratford, mais aucun chercheur ne s’est penché sur ce qu’il conviendrait d’entendre par « tradition de traduction littéraire au Canada ». Après avoir exposé ces carences qui, à bien des égards, laissent perplexe en contexte de bilinguisme officiel, il s’agira, dans un deuxième temps, i) de définir l’idée de « tradition » ; ii) d’avancer l’hypothèse selon laquelle il existe depuis 1980 plusieurs traditions conflictuelles de traduction littéraire au Canada ; iii) de formuler des questions de méthodologie susceptibles d’en appréhender l’émergence, l’essor et, le cas échéant, l’étiolement ; iv) de souligner l’importance des bibliographies pour la mise au jour de nouvelles pistes analytiques d’ordre tant quantitatif que qualitatif dans le domaine de la traductologie.
Crustal anisotropy from tectonic tremor under Washington State in the Cascadia
Authors: Huesca‐Pérez Eduardo , Ghosh Abhijit 
Published: February 2015

AbstractWe present new observations of crustal shear wave anisotropy extracted from nonvolcanic tremor in Cascadia under Washington State. Measurements of crustal anisotropy are extremely sparse and limited in this area mainly due to low level of seismicity. Abundance of tremor activity during slow earthquakes offers a unique opportunity to measure anisotropy parameters of the continental crust using tremor signal. To accomplish this, polarization and splitting analyses of nonvolcanic tremor are performed using three‐component broadband seismic stations. Splitting times measurements range between 0.08 and 0.17 s and similar to the splitting magnitude typically observed in the continental crust. Fast direction of shear wave anisotropy generally trends ESE‐WNW. Fast polarization directions are, in general, perpendicular to the prevailing maximum compressive stress field but tend to be parallel to several mapped EW and ESE‐WNW trending faults in this area. The observed spatial pattern of anisotropy is likely controlled by faulting that accommodates NS compression resulting from the tectonic movement of the Oregon block toward north. Existence of several EW trending crustal faults and source parameters of crustal earthquakes at depth, consistent with the regional stress regime, indicate that these faults may be the dominant factor causing the observed pattern of shear wave anisotropy.
Sources of discrepancies between satellite‐derived and land surface model estimates of latent heat fluxes
Authors: Lipton Alan E. , Liang Pan , Jiménez Carlos , Moncet Jean‐Luc , Aires Filipe , Prigent Catherine , Lynch Richard , Galantowicz John F. , d'Entremont Robert P. , Uymin Gennady 
Published: February 2015

AbstractMonthly‐average estimates of latent heat flux have been derived from a combination of satellite‐derived microwave emissivities, day‐night differences in land surface temperature (from microwave AMSR‐E), downward solar and infrared fluxes from ISCCP cloud analysis, and MODIS visible and near‐infrared surface reflectances. The estimates, produced with a neural network, were compared with data from the Noah land surface model, as produced for GLDAS‐2, and with two alternative estimates derived from different datasets and methods. Areas with extensive, persistent, substantial discrepancies between the satellite and land surface model fluxes have been analyzed with the aid of data from flux towers. The sources of discrepancies were found to include problems with the model surface roughness length and turbulent exchange coefficients for midlatitude cropland areas in summer, inaccuracies in the precipitation data that were used as forcing for the land surface model, and model underestimation of transpiration in some forests during dry periods. At the tower sites analyzed, agreement with tower data was generally closer for our satellite‐derived fluxes than for the land surface model fluxes, in terms of monthly averages.
The influence of rapid, millennial scale climate change on nitrogen isotope dynamics of the Cariaco Basin during marine isotope stage 3
Authors: Gibson Kelly Ann , Thunell Robert C. , Tappa Eric J. , Peterson Larry C. , McConnell Martha 
Published: February 2015

AbstractUnderstanding changes to the marine nitrogen cycle on millennial and shorter time scales can help determine the influence of rapid climate change on the fixed N pool and its sources and sinks. Rapid changes in denitrification have been observed in the eastern tropical North Pacific (ETNP) and Arabian Sea; however, millennial scale δ15N records in regions influenced by N2 fixation are sparse. We present a sedimentary δ15N record from the Cariaco Basin during marine isotope stage (MIS) 3 (~35–55 ka). The δ15N record displays a pattern of millennial scale variability that tracks the Greenland ice core Dansgaard‐Oeschger cycles, with higher values observed during interstadial periods, lower values during stadial periods, and abrupt transitions in between. Conditions during interstadials are similar to those at present in the Cariaco Basin, with the sedimentary δ15N signal reflecting a combination of local processes and an imported regional signal. If interpreted to reflect regional processes, the interstadial δ15N values (average ~5.1‰) support the argument that N2 fixation did not increase in the tropical North Atlantic during the last glacial. The lower δ15N values during stadials, when lower sea level resulted in increased physical isolation of the basin, can be explained primarily by local processes. In spite of the importance of local processes, striking similarity is observed between the Cariaco record and millennial scale δ15N records from the ETNP and Arabian Sea. The apparent synchronicity of changes observed in all three regions suggests an atmospheric teleconnection between the three sites and high‐latitude climate forcing during MIS 3.
Synthesis of D‐ and L‐Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process
Authors: Parmeggiani Fabio , Lovelock Sarah L. , Weise Nicholas J. , Ahmed Syed T. , Turner Nicholas J. 
Published: February 2015

AbstractThe synthesis of substituted D‐phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one‐pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high‐throughput solid‐phase screening method has also been developed to identify PALs with higher rates of formation of non‐natural D‐phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the D‐configured product. Furthermore, the system was extended to the preparation of those L‐phenylalanines which are obtained with a low ee value using PAL amination.
Enzymatic Basis of “Hybridity” in Thiomarinol Biosynthesis
Authors: Dunn Zachary D. , Wever Walter J. , Economou Nicoleta J. , Bowers Albert A. , Li Bo 
Published: February 2015

AbstractThiomarinol is a naturally occurring double‐headed antibiotic that is highly potent against methicillin‐resistant Staphylococcus aureus. Its structure comprises two antimicrobial subcomponents, pseudomonic acid analogue and holothin, linked by an amide bond. TmlU was thought to be the sole enzyme responsible for this amide‐bond formation. In contrast to this idea, we show that TmlU acts as a CoA ligase that activates pseudomonic acid as a thioester that is processed by the acetyltransferase HolE to catalyze the amidation. TmlU prefers complex acyl acids as substrates, whereas HolE is relatively promiscuous, accepting a range of acyl‐CoA and amine substrates. Our results provide detailed biochemical information on thiomarinol biosynthesis, and evolutionary insight regarding how the pseudomonic acid and holothin pathways converge to generate this potent hybrid antibiotic. This work also demonstrates the potential of TmlU/HolE enzymes as engineering tools to generate new “hybrid” molecules.
Biosynthesis of the Carbamoylated D‐Gulosamine Moiety of Streptothricins: Involvement of a Guanidino‐N‐glycosyltransferase and an N‐Acetyl‐D‐gulosamine Deacetylase
Authors: Guo Zhengyan , Li Jine , Qin Hua , Wang Min , Lv Xun , Li Xuebing , Chen Yihua 
Published: February 2015

AbstractStreptothricins (STNs) are atypical aminoglycosides containing a rare carbamoylated D‐gulosamine (D‐GulN) moiety, and the antimicrobial activity of STNs has been exploited for crop protection. Herein, the biosynthetic pathway of the carbamoylated D‐GulN moiety was delineated. An N‐acetyl‐D‐galactosamine is first attached to the streptolidine lactam by the glycosyltransferse StnG and then epimerized to N‐acetyl‐D‐gulosamine by the putative epimerase StnJ. After carbamoylation by the carbamoyltransferase StnQ, N‐acetyl‐D‐GulN is deacetylated by StnI to furnish the carbamoylated D‐GulN moiety. In vitro studies characterized two novel enzymes: StnG is an unprecedented GT‐A fold N‐glycosyltransferase that glycosylates the imine nitrogen atom of guanidine, and StnI is the first reported N‐acetyl‐D‐GulN deacetylase.
High Selectivity for Ethylene from Carbon Dioxide Reduction over Copper Nanocube Electrocatalysts
Authors: Roberts F. Sloan , Kuhl Kendra P. , Nilsson Anders 
Published: February 2015

AbstractNanostructured surfaces have been shown to greatly enhance the activity and selectivity of many different catalysts. Here we report a nanostructured copper surface that gives high selectivity for ethylene formation from electrocatalytic CO2 reduction. The nanostructured copper is easily formed in situ during the CO2 reduction reaction, and scanning electron microscopy (SEM) shows the surface to be dominated by cubic structures. Using online electrochemical mass spectrometry (OLEMS), the onset potentials and relative selectivity toward the volatile products (ethylene and methane) were measured for several different copper surfaces and single crystals, relating the cubic shape of the copper surface to the greatly enhanced ethylene selectivity. The ability of the cubic nanostructure to so strongly favor multicarbon product formation from CO2 reduction, and in particular ethylene over methane, is unique to this surface and is an important step toward developing a catalyst that has exclusive selectivity for multicarbon products.
Oxidative Addition of Carbon–Carbon Bonds to Gold
Authors: Joost Maximilian , Estévez Laura , Miqueu Karinne , Amgoune Abderrahmane , Bourissou Didier 
Published: February 2015

AbstractThe oxidative addition of strained CC bonds (biphenylene, benzocyclobutenone) to DPCb (diphosphino‐carborane) gold(I) complexes is reported. The resulting cationic organogold(III) complexes have been isolated and fully characterized. Experimental conditions can be adjusted to obtain selectively acyl gold(III) complexes resulting from oxidative addition of either the C(aryl)C(O) or C(alkyl)C(O) bond of benzocyclobutenone. DFT calculations provide mechanistic insight into this unprecedented transformation.
Interrupted Chalcogenide‐Based Zeolite‐Analogue Semiconductor: Atomically Precise Doping for Tunable Electro‐/Photoelectrochemical Properties
Authors: Lin Jian , Dong Youzhen , Zhang Qian , Hu Dandan , Li Na , Wang Le , Liu Yang , Wu Tao 
Published: February 2015

AbstractIncorporation of semiconductor property into zeolite materials is a plausible approach to graft oxide zeolites with multifunctionality in which both electronic/optoelectronic functions and high porosity are integrated. However, creating such semiconductor zeolites, especially the ones with controllable function regulation still remains as a great synthetic challenge over the years. Hereby, we reported the first case of an interrupted chalcogenide‐based zeolite‐analog semiconductor with an entirely new boracite‐related framework and specific sites at the interrupted section. The semiconducting nature and band structure of this open‐framework n‐type semiconductor material were characterized with solid‐state UV/Vis diffuse reflectance spectroscopy and Mott–Schottky measurements. More importantly, the In–Se chalcogenide zeolite analog was for the first time explored as an effective electrocatalyst for the oxygen reduction reaction (ORR). The specific indium sites served as active centers and proved to be responsible for a superior ORR activity. Meanwhile, these specific sites could be precisely replaced by bismuth(III) ions, leading to facile manipulation in their electro‐/photoelectrochemical properties. Such atomically precise doping successfully implemented at the semiconductor zeolite material with specifically interrupted sites presents a very promising route for accurately regulating electronic structure and photoelectrical properties of other open‐framework semiconductor materials.
Lewis Acid Promoted Ruthenium(II)‐Catalyzed Etherifications by Selective Hydrogenation of Carboxylic Acids/Esters
Authors: Li Yuehui , Topf Christoph , Cui Xinjiang , Junge Kathrin , Beller Matthias 
Published: February 2015

AbstractEthers are of fundamental importance in organic chemistry and they are an integral part of valuable flavors, fragrances, and numerous bioactive compounds. In general, the reduction of esters constitutes the most straightforward preparation of ethers. Unfortunately, this transformation requires large amounts of metal hydrides. Presented herein is a bifunctional catalyst system, consisting of Ru/phosphine complex and aluminum triflate, which allows selective synthesis of ethers by hydrogenation of esters or carboxylic acids. Different lactones were reduced in good yields to the desired products. Even challenging aromatic and aliphatic esters were reduced to the desired products. Notably, the in situ formed catalyst can be reused several times without any significant loss of activity.
Well‐Defined CuC2F5 Complexes and Pentafluoroethylation of Acid Chlorides
Authors: Panferova Liubov I. , Miloserdov Fedor M. , Lishchynskyi Anton , Martínez Belmonte Marta , Benet‐Buchholz Jordi , Grushin Vladimir V. 
Published: February 2015

AbstractFour new well‐defined CuI complexes bearing a C2F5 ligand have been prepared and fully characterized: [(Ph3P)2CuC2F5] (2), [(bpy)CuC2F5] (3), [(Ph3P)Cu(phen)C2F5] (4), and [(IPr*)CuC2F5] (5). X‐ray structures of all four have been determined, showing that the C2F5‐ligated Cu atom can be di‐ (5), tri‐ (2 and 3), and tetracoordinate (4). The mixed phen‐PPh3 complex 4 is a highly efficient fluoroalkylating agent for a broad variety of acid chlorides. This high‐yielding transformation represents the first general method for the synthesis of RCOC2F5 from the corresponding RCOCl.
Ultralight and hydrophobic nanofibrillated cellulose aerogels from coconut shell with ultrastrong adsorption properties
Authors: Wan Caichao , Lu Yun , Jiao Yue , Jin Chunde , Sun Qingfeng , Li Jian 
Published: February 2015

ABSTRACTUltralight aerogels based on nanofibrillated cellulose (NFC) isolated from coconut shell were successfully prepared via a mild fast method, which included chemical pretreatment, ultrasonic isolation, solvent exchange, and tert‐butanol freeze drying. The as‐prepared NFC aerogels with complex three‐dimensional fibrillar networks had a low bulk density of 0.84 mg/cm3 (specific surface area = 9.1 m2/g and pore volume = 0.025 cm3/g), maintained a cellulose I crystal structure, and showed more superior thermal stability than the coconut shell raw materials. After the hydrophobic modification by methyl trichlorosilane (MTCS), the NFC aerogels exhibited high water repellency properties, an ultrastrong oil‐adsorption capacity (542 times that of the original dry weight of diesel oil), and superior oil–water separation performance. Moreover, the absorption capabilities of the MTCS‐treated NFC aerogels were as high as 296−669 times their own weights for various organic solvents and oil. Thus, this class of high‐performance adsorbing materials might be useful for dealing with chemical leaks and oil spills. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42037.