bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of nutrition in early pregnancy on the periparturient relaxation of immunity to gastro-intestinal parasitism in prolific ewes
Authors: Valderrábano J. , Uriarte J. 
Published: May 2017

AbstractThe rôle of body reserves stored during early pregnancy on the periparturient breakdown of resistance to nematode parasites was investigated. From the 35th day of pregnancy, 46 ewes were distributed in four groups and given access to a lucerne pelleted diet. Two groups were given food at maintenance (M and C) and the other two were offered food either ad libitum (H) or at 0·70 their maintenance requirements (L) in order to achieve three well differentiated levels of body reserves by the 90th day of pregnancy when backfat thickness reached a mean value of 10·6, 7·5, 7·4 and 5·0 mm for H, M, C, and L treatments respectively. After the 90th day of pregnancy all animals were given food at 50 g/kg live weight per day. All ewes in groups H, M and L received 5000 infective larvae per week (40% Teladorsagia circumcincta, 40% Trichostrongylus colubriformis, 20% Haemonchus contortus) from 5 weeks before to 3 weeks after lambing. The animals in group C remained as uninfected controls.Host resistance, as measured by faecal egg counts, was significantly affected by the nutritional treatment established during early pregnancy, showing a mean excretion of 546, 766 and 1007 eggs per gram (e.p.g. ) for H, M, and L treatments, respectively, until 3 weeks post lambing. This response was accompanied by a significant effect on circulating eosinophils and better fed ewes showed a higher concentration with a maximum mean value of 10·1, 6·9, 5·5 and 4·0 cells per mm3 for H, M, L and C treatments, respectively, 2 weeks post infection. The effect of the worm infection per se was evident in that the lambs of the M treatment ewes grew at 0·90 of the rate of those in the control treatment (189 v. 213 g/day). Ad libitum feeding in early pregnancy appeared to sufficiently compensate for this depressive effect, with the H ewes producing lambs that grew at a rate similar to those of the C ewes (213 v. 213 g/day).The results support the view that fat mass stored by ewes in early pregnancy is involved in the expression of immunity against gastro-intestinal nematode infection around parturition. Furthermore, the depressive effect of ewes’ infection on lambs’ growth rate can be overcome by increasing the plane of nutrition of their dams. These results have clear implications for grazing animals, particularly their nutritional management in early pregnancy and provide a simple management strategy in sustainable management systems.
An in vivo strategy to counteract post-administration anticoagulant activity of azido-Warfarin
Authors: Ursuegui Sylvain , Recher Marion , Krężel Wojciech , Wagner Alain 
Published: May 2017

AbstractDrugs, usually long acting and metabolically stable molecules, might be the source of adverse effects triggered by complex drug interactions, anaphylaxis and drug-induced coagulopathy. To circumvent this growing drug safety issue, we herein investigate the opportunity offered by bio-orthogonal chemistry for in vivo drug neutralization. We design a small-molecule anticoagulant drug (Warfarin) containing an azide group that acts as a safety pin. It allows drug deactivation and restoration of physiological coagulation via in vivo click reaction with a suitable cyclooctyne-based neutralizing agent. In this strategy, the new molecule formed by reaction of the drug and the antidote is deprived of biological activity and prone to fast renal clearance. This ‘Click & Clear’ approach lays ground for new strategies in designing drugs with switchable biophysical properties.
Extended fisheries recovery timelines in a changing environment
Authors: Britten Gregory L. , Dowd Michael , Kanary Lisa , Worm Boris 
Published: May 2017

AbstractRebuilding depleted fish stocks is an international policy goal and a 2020 Aichi target under the Convention on Biological Diversity. However, stock productivity may shift with future climate change, with unknown consequences for sustainable harvesting, biomass targets and recovery timelines. Here we develop a stochastic modelling framework to characterize variability in the intrinsic productivity parameter (r) and carrying capacity (K) for 276 global fish stocks worldwide. We use models of dynamic stock productivity fitted via Bayesian inference to forecast rebuilding timelines for depleted stocks. In scenarios without fishing, recovery probabilities are reduced by 19%, on average, relative to models assuming static productivity. Fishing at 90% of the maximum sustainable rate depresses recovery probabilities by 42%, on average, relative to static models. This work reveals how a changing environmental context can delay the rebuilding of depleted fish stocks, and provides a framework to account for the potential impacts of environmental change on the productivity of wildlife populations more broadly.
Concerted regulation of retinal pigment epithelium basement membrane and barrier function by angiocrine factors
Authors: Benedicto Ignacio , Lehmann Guillermo L. , Ginsberg Michael , Nolan Daniel J. , Bareja Rohan , Elemento Olivier , Salfati Zelda , Alam Nazia M. , Prusky Glen T. , Llanos Pierre , Rabbany Sina Y. , Maminishkis Arvydas , Miller Sheldon S. , Rafii Shahin , Rodriguez-Boulan Enrique 
Published: May 2017

AbstractThe outer blood-retina barrier is established through the coordinated terminal maturation of the retinal pigment epithelium (RPE), fenestrated choroid endothelial cells (ECs) and Bruch’s membrane, a highly organized basement membrane that lies between both cell types. Here we study the contribution of choroid ECs to this process by comparing their gene expression profile before (P5) and after (P30) the critical postnatal period when mice acquire mature visual function. Transcriptome analyses show that expression of extracellular matrix-related genes changes dramatically over this period. Co-culture experiments support the existence of a novel regulatory pathway: ECs secrete factors that remodel RPE basement membrane, and integrin receptors sense these changes triggering Rho GTPase signals that modulate RPE tight junctions and enhance RPE barrier function. We anticipate our results will spawn a search for additional roles of choroid ECs in RPE physiology and disease.
An apicobasal gradient of Rac activity determines protrusion form and position
Authors: Couto Africa , Mack Natalie Ann , Favia Lucrezia , Georgiou Marios 
Published: May 2017

AbstractEach cell within a polarized epithelial sheet must align and correctly position a wide range of subcellular structures, including actin-based dynamic protrusions. Using in vivo inducible transgenes that can sense or modify Rac activity, we demonstrate an apicobasal gradient of Rac activity that is required to correctly form and position distinct classes of dynamic protrusion along the apicobasal axis of the cell. We show that we can modify the Rac activity gradient in genetic mutants for specific polarity proteins, with consequent changes in protrusion form and position and additionally show, using photoactivatable Rac transgenes, that it is the level of Rac activity that determines protrusion form. Thus, we demonstrate a mechanism by which polarity proteins can spatially regulate Rac activity and the actin cytoskeleton to ensure correct epithelial cell shape and prevent epithelial-to-mesenchymal transitions.
Plasmonic computing of spatial differentiation
Authors: Zhu Tengfeng , Zhou Yihan , Lou Yijie , Ye Hui , Qiu Min , Ruan Zhichao , Fan Shanhui 
Published: May 2017

AbstractOptical analog computing offers high-throughput low-power-consumption operation for specialized computational tasks. Traditionally, optical analog computing in the spatial domain uses a bulky system of lenses and filters. Recent developments in metamaterials enable the miniaturization of such computing elements down to a subwavelength scale. However, the required metamaterial consists of a complex array of meta-atoms, and direct demonstration of image processing is challenging. Here, we show that the interference effects associated with surface plasmon excitations at a single metal–dielectric interface can perform spatial differentiation. And we experimentally demonstrate edge detection of an image without any Fourier lens. This work points to a simple yet powerful mechanism for optical analog computing at the nanoscale.
Mistranslation can enhance fitness through purging of deleterious mutations
Authors: Bratulic Sinisa , Toll-Riera Macarena , Wagner Andreas 
Published: May 2017

AbstractPhenotypic mutations are amino acid changes caused by mistranslation. How phenotypic mutations affect the adaptive evolution of new protein functions is unknown. Here we evolve the antibiotic resistance protein TEM-1 towards resistance on the antibiotic cefotaxime in an Escherichia coli strain with a high mistranslation rate. TEM-1 populations evolved in such strains endow host cells with a general growth advantage, not only on cefotaxime but also on several other antibiotics that ancestral TEM-1 had been unable to deactivate. High-throughput sequencing of TEM-1 populations shows that this advantage is associated with a lower incidence of weakly deleterious genotypic mutations. Our observations show that mistranslation is not just a source of noise that delays adaptive evolution. It could even facilitate adaptive evolution by exacerbating the effects of deleterious mutations and leading to their more efficient purging. The ubiquity of mistranslation and its effects render mistranslation an important factor in adaptive protein evolution.
Impact of simultaneous exposure to arboviruses on infection and transmission by Aedes aegypti mosquitoes
Authors: Rückert Claudia , Weger-Lucarelli James , Garcia-Luna Selene M. , Young Michael C. , Byas Alex D. , Murrieta Reyes A. , Fauver Joseph R. , Ebel Gregory D. 
Published: May 2017

AbstractThe recent emergence of both chikungunya and Zika viruses in the Americas has significantly expanded their distribution and has thus increased the possibility that individuals may become infected by more than one Aedes aegypti-borne virus at a time. Recent clinical data support an increase in the frequency of coinfection in human patients, raising the likelihood that mosquitoes could be exposed to multiple arboviruses during one feeding episode. The impact of coinfection on the ability of relevant vector species to transmit any of these viruses (that is, their vector competence) has not been determined. Thus, we here expose Ae. aegypti mosquitoes to chikungunya, dengue-2 or Zika viruses, both individually and as double and triple infections. Our results show that these mosquitoes can be infected with and can transmit all combinations of these viruses simultaneously. Importantly, infection, dissemination and transmission rates in mosquitoes are only mildly affected by coinfection.
Optimized fragmentation schemes and data analysis strategies for proteome-wide cross-link identification
Authors: Liu Fan , Lössl Philip , Scheltema Richard , Viner Rosa , Heck Albert J. R. 
Published: May 2017

AbstractWe describe optimized fragmentation schemes and data analysis strategies substantially enhancing the depth and accuracy in identifying protein cross-links using non-restricted whole proteome databases. These include a novel hybrid data acquisition strategy to sequence cross-links at both MS2 and MS3 level and a new algorithmic design XlinkX v2.0 for data analysis. As proof-of-concept we investigated proteome-wide protein interactions in E. coli and HeLa cell lysates, respectively, identifying 1,158 and 3,301 unique cross-links at ∼1% false discovery rate. These protein interaction repositories provide meaningful structural information on many endogenous macromolecular assemblies, as we showcase on several protein complexes involved in translation, protein folding and carbohydrate metabolism.
Self-assembly of a supramolecular hexagram and a supramolecular pentagram
Authors: Jiang Zhilong , Li Yiming , Wang Ming , Song Bo , Wang Kun , Sun Mingyu , Liu Die , Li Xiaohong , Yuan Jie , Chen Mingzhao , Guo Yuan , Yang Xiaoyu , Zhang Tong , Moorefield Charles N. , Newkome George R. , Xu Bingqian , Li Xiaopeng , Wang Pingshan 
Published: May 2017

AbstractFive- and six-pointed star structures occur frequently in nature as flowers, snow-flakes, leaves and so on. These star-shaped patterns are also frequently used in both functional and artistic man-made architectures. Here following a stepwise synthesis and self-assembly approach, pentagonal and hexagonal metallosupramolecules possessing star-shaped motifs were prepared based on the careful design of metallo-organic ligands (MOLs). In the MOL design and preparation, robust ruthenium–terpyridyl complexes were employed to construct brominated metallo-organic intermediates, followed by a Suzuki coupling reaction to achieve the required ensemble. Ligand LA (VRu2+X, V=bisterpyridine, X=tetraterpyridine, Ru=Ruthenium) was initially used for the self-assembly of an anticipated hexagram upon reaction with Cd2+ or Fe2+; however, unexpected pentagonal structures were formed, that is, [Cd5LA5]30+ and [Fe5LA5]30+. In our redesign, LB [V(Ru2+X)2] was synthesized and treated with 60° V-shaped bisterpyridine (V) and Cd2+ to create hexagonal hexagram [Cd12V3LB3]36+ along with traces of the triangle [Cd3V3]6+. Finally, a pure supramolecular hexagram [Fe12V3LB3]36+ was successfully isolated in a high yield using Fe2+ with a higher assembly temperature.
Brønsted acid-catalysed enantioselective construction of axially chiral arylquinazolinones
Authors: Wang Yong-Bin , Zheng Sheng-Cai , Hu Yu-Mei , Tan Bin 
Published: May 2017

AbstractThe axially chiral arylquinazolinone acts as a privileged structural scaffold, which is present in a large number of natural products and biologically active compounds as well as in chiral ligands. However, a direct catalytic enantioselective approach to access optically pure arylquinazolinones has been underexplored. Here we show a general and efficient approach to access enantiomerically pure arylquinazolinones in one-pot fashion catalysed by chiral phosphoric acids. A variety of axially chiral arylquinazolinones were obtained in high yields with good to excellent enantioselectivities under mild condition. Furthermore, we disclosed a method for atroposelective synthesis of alkyl-substituted arylquinazolinones involving Brønsted acid-catalysed carbon–carbon bond cleavage strategy. Finally, the asymmetric total synthesis of eupolyphagin bearing a cyclic arylquinazolinone skeleton was accomplished with an overall yield of 32% in six steps by utilizing the aforementioned methodology.
Hif-1α regulates macrophage-endothelial interactions during blood vessel development in zebrafish
Authors: Gerri Claudia , Marín-Juez Rubén , Marass Michele , Marks Alora , Maischein Hans-Martin , Stainier Didier Y R. 
Published: May 2017

AbstractMacrophages are known to interact with endothelial cells during developmental and pathological angiogenesis but the molecular mechanisms modulating these interactions remain unclear. Here, we show a role for the Hif-1α transcription factor in this cellular communication. We generated hif-1aa;hif-1ab double mutants in zebrafish, hereafter referred to as hif-1α mutants, and find that they exhibit impaired macrophage mobilization from the aorta-gonad-mesonephros (AGM) region as well as angiogenic defects and defective vascular repair. Importantly, macrophage ablation is sufficient to recapitulate the vascular phenotypes observed in hif-1α mutants, revealing for the first time a macrophage-dependent angiogenic process during development. Further substantiating our observations of vascular repair, we find that most macrophages closely associated with ruptured blood vessels are Tnfα-positive, a key feature of classically activated macrophages. Altogether, our data provide genetic evidence that Hif-1α regulates interactions between macrophages and endothelial cells starting with the mobilization of macrophages from the AGM.
Symbiont community stability through severe coral bleaching in a thermally extreme lagoon
Authors: Smith E. G. , Vaughan G. O. , Ketchum R. N. , McParland D. , Burt J. A. 
Published: May 2017

AbstractCoral reefs are threatened by climate change as coral-algal symbioses are currently living close to their upper thermal limits. The resilience of the algal partner plays a key role in determining the thermal tolerance of the coral holobiont and therefore, understanding the acclimatory limits of present day coral-algal symbioses is fundamental to forecasting corals’ responses to climate change. This study characterised the symbiont community in a highly variable and thermally extreme (Max = 37.5 °C, Min = 16.8 °C) lagoon located in the southern Persian/Arabian Gulf using next generation sequencing of ITS2 amplicons. Despite experiencing extreme temperatures, severe bleaching and many factors that would be expected to promote the presence of, or transition to clade D dominance, the symbiont communities of the lagoon remain dominated by the C3 variant, Symbiodinium thermophilum. The stability of this symbiosis across multiple genera with different means of symbiont transmission highlights the importance of Symbiodinium thermophilum for corals living at the acclimatory limits of modern day corals. Corals in this extreme environment did not undergo adaptive bleaching, suggesting they are living at the edge of their acclimatory potential and that this valuable source of thermally tolerant genotypes may be lost in the near future under climate change.
An ultra-high gain and efficient amplifier based on Raman amplification in plasma
Authors: Vieux G. , Cipiccia S. , Grant D. W. , Lemos N. , Grant P. , Ciocarlan C. , Ersfeld B. , Hur M. S. , Lepipas P. , Manahan G. G. , Raj G. , Reboredo Gil D. , Subiel A. , Welsh G. H. , Wiggins S. M. , Yoffe S. R. , Farmer J. P. , Aniculaesei C. , Brunetti E. , Yang X. , Heathcote R. , Nersisyan G. , Lewis C. L. S. , Pukhov A. , Dias J. M. , Jaroszynski D. A. 
Published: May 2017

AbstractRaman amplification arising from the excitation of a density echelon in plasma could lead to amplifiers that significantly exceed current power limits of conventional laser media. Here we show that 1–100 J pump pulses can amplify picojoule seed pulses to nearly joule level. The extremely high gain also leads to significant amplification of backscattered radiation from “noise”, arising from stochastic plasma fluctuations that competes with externally injected seed pulses, which are amplified to similar levels at the highest pump energies. The pump energy is scattered into the seed at an oblique angle with 14 J sr−1, and net gains of more than eight orders of magnitude. The maximum gain coefficient, of 180 cm−1, exceeds high-power solid-state amplifying media by orders of magnitude. The observation of a minimum of 640 J sr−1 directly backscattered from noise, corresponding to ≈10% of the pump energy in the observation solid angle, implies potential overall efficiencies greater than 10%.
Mapping few-femtosecond slices of ultra-relativistic electron bunches
Authors: Plath Tim , Lechner Christoph , Miltchev Velizar , Amstutz Philipp , Ekanayake Nagitha , Lazzarino Leslie Lamberto , Maltezopoulos Theophilos , Bödewadt Jörn , Laarmann Tim , Roßbach Jörg 
Published: May 2017

AbstractFree-electron lasers are unique sources of intense and ultra-short x-ray pulses that led to major scientific breakthroughs across disciplines from matter to materials and life sciences. The essential element of these devices are micrometer-sized electron bunches with high peak currents, low energy spread, and low emittance. Advanced FEL concepts such as seeded amplifiers rely on the capability of analyzing and controlling the electron beam properties with few-femtosecond time resolution. One major challenge is to extract tomographic slice parameters instead of projected electron beam properties. Here, we demonstrate that a radio-frequency deflector in combination with a dipole spectrometer not only allows for single-shot extraction of a seeded FEL pulse profile, but also provides information on the electron slice emittance and energy spread. The seeded FEL power profile can be directly related to the derived slice emittance as a function of intra-bunch coordinate with a resolution down to a few femtoseconds.
Droplet Digital PCR versus qPCR for gene expression analysis with low abundant targets: from variable nonsense to publication quality data
Authors: Taylor Sean C. , Laperriere Genevieve , Germain Hugo 
Published: May 2017

AbstractQuantitative PCR (qPCR) has become the gold standard technique to measure cDNA and gDNA levels but the resulting data can be highly variable, artifactual and non-reproducible without appropriate verification and validation of both samples and primers. The root cause of poor quality data is typically associated with inadequate dilution of residual protein and chemical contaminants that variably inhibit Taq polymerase and primer annealing. The most susceptible, frustrating and often most interesting samples are those containing low abundant targets with small expression differences of 2-fold or lower. Here, Droplet Digital PCR (ddPCR) and qPCR platforms were directly compared for gene expression analysis using low amounts of purified, synthetic DNA in well characterized samples under identical reaction conditions. We conclude that for sample/target combinations with low levels of nucleic acids (Cq ≥ 29) and/or variable amounts of chemical and protein contaminants, ddPCR technology will produce more precise, reproducible and statistically significant results required for publication quality data. A stepwise methodology is also described to choose between these complimentary technologies to obtain the best results for any experiment.
Textured NiSe2 Film: Bifunctional Electrocatalyst for Full Water Splitting at Remarkably Low Overpotential with High Energy Efficiency
Authors: Swesi Abdurazag T. , Masud Jahangir , Liyanage Wipula P. R. , Umapathi Siddesh , Bohannan Eric , Medvedeva Julia , Nath Manashi 
Published: May 2017

AbstractHerein we have shown that electrodeposited NiSe2 can be used as a bifunctional electrocatalyst under alkaline conditions to split water at very low potential by catalyzing both oxygen evolution and hydrogen evolution reactions at anode and cathode, respectively, achieving a very high electrolysis energy efficiency exceeding 80% at considerably high current densities (100 mA cm−2). The OER catalytic activity as well as electrolysis energy efficiency surpasses any previously reported OER electrocatalyst in alkaline medium and energy efficiency of an electrolyzer using state-of-the-art Pt and RuO2 as the HER and OER catalyst, respectively. Through detailed electrochemical and structural characterization, we have shown that the enhanced catalytic activity is attributed to directional growth of the electrodeposited film that exposes a Ni-rich lattice plane as the terminating plane, as well as increased covalency of the selenide lattice which decreases the Ni(II) to Ni(III) oxidation potential. Thereby, the high efficiency along with extended stability makes NiSe2 as the most efficient water electrolyzer known to-date.