bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paclobutrazol induces tolerance in tomato to deficit irrigation through diversified effects on plant morphology, physiology and metabolism
Authors: Pal Sikander , Zhao Jiangsan , Khan Asif , Yadav Narendra Singh , Batushansky Albert , Barak Simon , Rewald Boris , Fait Aaron , Lazarovitch Naftali , Rachmilevitch Shimon 
Published: December 2016

AbstractDwindling water resources combined with meeting the demands for food security require maximizing water use efficiency (WUE) both in rainfed and irrigated agriculture. In this regard, deficit irrigation (DI), defined as the administration of water below full crop-water requirements (evapotranspiration), is a valuable practice to contain irrigation water use. In this study, the mechanism of paclobutrazol (Pbz)-mediated improvement in tolerance to water deficit in tomato was thoroughly investigated. Tomato plants were subjected to normal irrigated and deficit irrigated conditions plus Pbz application (0.8 and 1.6 ppm). A comprehensive morpho-physiological, metabolomics and molecular analysis was undertaken. Findings revealed that Pbz application reduced plant height, improved stem diameter and leaf number, altered root architecture, enhanced photosynthetic rates and WUE of tomato plants under deficit irrigation. Pbz differentially induced expression of genes and accumulation of metabolites of the tricarboxylic acid (TCA) cycle, γ-aminobutyric acid (GABA-shunt pathway), glutathione ascorbate (GSH-ASC)-cycle, cell wall and sugar metabolism, abscisic acid (ABA), spermidine (Spd) content and expression of an aquaporin (AP) protein under deficit irrigation. Our results suggest that Pbz application could significantly improve tolerance in tomato plants under limited water availability through selective changes in morpho-physiology and induction of stress-related molecular processes.
Imaging molecular geometry with electron momentum spectroscopy
Authors: Wang Enliang , Shan Xu , Tian Qiguo , Yang Jing , Gong Maomao , Tang Yaguo , Niu Shanshan , Chen Xiangjun 
Published: December 2016

AbstractElectron momentum spectroscopy is a unique tool for imaging orbital-specific electron density of molecule in momentum space. However, the molecular geometry information is usually veiled due to the single-centered character of momentum space wavefunction of molecular orbital (MO). Here we demonstrate the retrieval of interatomic distances from the multicenter interference effect revealed in the ratios of electron momentum profiles between two MOs with symmetric and anti-symmetric characters. A very sensitive dependence of the oscillation period on interatomic distance is observed, which is used to determine F-F distance in CF4 and O-O distance in CO2 with sub-Ångström precision. Thus, using one spectrometer, and in one measurement, the electron density distributions of MOs and the molecular geometry information can be obtained simultaneously. Our approach provides a new robust tool for imaging molecules with high precision and has potential to apply to ultrafast imaging of molecular dynamics if combined with ultrashort electron pulses in the future.
Quantum phase transition induced by real-space topology
Authors: Li C. , Zhang G. , Lin S. , Song Z. 
Published: December 2016

AbstractA quantum phase transition (QPT), including both topological and symmetry breaking types, is usually induced by the change of global parameters, such as external fields or global coupling constants. In this work, we demonstrate the existence of QPT induced by the real-space topology of the system. We investigate the groundstate properties of the tight-binding model on a honeycomb lattice with the torus geometry based on exact results. It is shown that the ground state experiences a second-order QPT, exhibiting the scaling behavior, when the torus switches to a tube, which reveals the connection between quantum phase and the real-space topology of the system.
Simultaneous Analysis of Secondary Structure and Light Scattering from Circular Dichroism Titrations: Application to Vectofusin-1
Authors: Vermeer Louic S. , Marquette Arnaud , Schoup Michel , Fenard David , Galy Anne , Bechinger Burkhard 
Published: December 2016

AbstractCircular Dichroism data are often decomposed into their constituent spectra to quantify the secondary structure of peptides or proteins but the estimation of the secondary structure content fails when light scattering leads to spectral distortion. If peptide-induced liposome self-association occurs, subtracting control curves cannot correct for this. We show that if the cause of the light scattering is independent from the peptide structural changes, the CD spectra can be corrected using principal component analysis (PCA). The light scattering itself is analysed and found to be in good agreement with backscattering experiments. This method therefore allows to simultaneously follow structural changes related to peptide-liposome binding as well as peptide induced liposome self-association. We apply this method to study the structural changes and liposome binding of vectofusin-1, a transduction enhancing peptide used in lentivirus based gene therapy. Vectofusin-1 binds to POPC/POPS liposomes, causing a reversal of the negative liposome charge at high peptide concentrations. When the peptide charges exactly neutralise the lipid charges on both leaflets reversible liposome self-association occurs. These results are in good agreement with biological observations and provide further insight into the conditions required for efficent transduction enhancement.
Direct measurements of multi-photon induced nonlinear lattice dynamics in semiconductors via time-resolved x-ray scattering
Authors: Williams G. Jackson , Lee Sooheyong , Walko Donald A. , Watson Michael A. , Jo Wonhuyk , Lee Dong Ryeol , Landahl Eric C. 
Published: December 2016

AbstractNonlinear optical phenomena in semiconductors present several fundamental problems in modern optics that are of great importance for the development of optoelectronic devices. In particular, the details of photo-induced lattice dynamics at early time-scales prior to carrier recombination remain poorly understood. We demonstrate the first integrated measurements of both optical and structural, material-dependent quantities while also inferring the bulk impulsive strain profile by using high spatial-resolution time-resolved x-ray scattering (TRXS) on bulk crystalline gallium arsenide. Our findings reveal distinctive laser-fluence dependent crystal lattice responses, which are not described by previous TRXS experiments or models. The initial linear expansion of the crystal upon laser excitation stagnates at a laser fluence corresponding to the saturation of the free carrier density before resuming expansion in a third regime at higher fluences where two-photon absorption becomes dominant. Our interpretations of the lattice dynamics as nonlinear optical effects are confirmed by numerical simulations and by additional measurements in an n-type semiconductor that allows higher-order nonlinear optical processes to be directly observed as modulations of x-ray diffraction lineshapes.
An exactly solvable, spatial model of mutation accumulation in cancer
Authors: Paterson Chay , Nowak Martin A. , Waclaw Bartlomiej 
Published: December 2016

AbstractOne of the hallmarks of cancer is the accumulation of driver mutations which increase the net reproductive rate of cancer cells and allow them to spread. This process has been studied in mathematical models of well mixed populations, and in computer simulations of three-dimensional spatial models. But the computational complexity of these more realistic, spatial models makes it difficult to simulate realistically large and clinically detectable solid tumours. Here we describe an exactly solvable mathematical model of a tumour featuring replication, mutation and local migration of cancer cells. The model predicts a quasi-exponential growth of large tumours, even if different fragments of the tumour grow sub-exponentially due to nutrient and space limitations. The model reproduces clinically observed tumour growth times using biologically plausible rates for cell birth, death, and migration rates. We also show that the expected number of accumulated driver mutations increases exponentially in time if the average fitness gain per driver is constant, and that it reaches a plateau if the gains decrease over time. We discuss the realism of the underlying assumptions and possible extensions of the model.
NF-κB signalling and cell fate decisions in response to a short pulse of tumour necrosis factor
Authors: Lee Robin E. C. , Qasaimeh Mohammad A. , Xia Xianfang , Juncker David , Gaudet Suzanne 
Published: December 2016

AbstractIn tissues and tumours, cell behaviours are regulated by multiple time-varying signals. While in the laboratory cells are often exposed to a stimulus for the duration of the experiment,in vivoexposures may be much shorter. In this study, we monitored NF-κB and caspase signalling in human cancer cells treated with a short pulse of Tumour Necrosis Factor (TNF). TNF is an inflammatory cytokine that can induce both the pro-survival NF-κB-driven gene transcription pathway and the pro-apoptotic caspase pathway. We find that a few seconds of exposure to TNF is sufficient to activate the NF-κB pathway in HeLa cells and induce apoptotic cell death in both HeLa and Kym-1 cells. Strikingly, a 1-min pulse of TNF can be more effective at killing than a 1-hour pulse, indicating that in addition to TNF concentration, duration of exposure also coordinates cell fate decisions.
A general nonaqueous sol-gel route to g-C3N4-coupling photocatalysts: the case of Z-scheme g-C3N4/TiO2 with enhanced photodegradation toward RhB under visible-light
Authors: Liu Xu , Chen Nan , Li Yuxiu , Deng Dongyang , Xing Xinxin , Wang Yude 
Published: December 2016

AbstractThe g-C3N4-coupling TiO2 photocatalysts with controllable particle size as well as the interface contact were prepared by a general nonaqueous sol-gel method. The structural and morphological features of g-C3N4/TiO2 were investigated through the X-ray diffraction, Fourier transformed infrared spectra, scanning electron microscopy and transmission electron microscopy, respectively. It is found the TiO2 nanoparticles with a size of 7.3 ± 1.6 nm are uniformly anchored on the surface of the g-C3N4 nanosheets in isolation. The photocatalytic properties of as-prepared g-C3N4/TiO2 were tested by degradation of Rhodamine B (RhB) under visible light, and an enhanced activity is observed. The mechanism of the enhanced activity was further investigated through N2 adsorption-desorption isotherms, UV-vis spectra, photoluminescence spectra, photoelectrochemical measurements, radical trapping experiments and X-ray photoelectron spectroscopy. Furthermore, the photocatalytic performances of obtained g-C3N4/TiO2 under sunlight were also evaluated in aspects of degradation efficiency and stability. The results indicate that the obtained g-C3N4/TiO2 is one promising photocatalyst for practical applications. The study of as-prepared g-C3N4/TiO2 also implies that the present method could be a general route of g-C3N4-coupling photocatalysts.
The dynamic monitoring of aeolian desertification land distribution and its response to climate change in northern China
Authors: Feng Lili , Jia Zhiqing , Li Qingxue 
Published: December 2016

AbstractAeolian desertification is poorly understood despite its importance for indicating environment change. Here we exploit Gaofen-1(GF-1) and Moderate Resolution Imaging Spectroradiometer (MODIS) data to develop a quick and efficient method for large scale aeolian desertification dynamic monitoring in northern China. This method, which is based on Normalized Difference Desertification Index (NDDI) calculated by band1 & band2 of MODIS reflectance data (MODIS09A1). Then we analyze spatial-temporal change of aeolian desertification area and detect its possible influencing factors, such as precipitation, temperature, wind speed and population by Convergent Cross Mapping (CCM) model. It suggests that aeolian desertification area with population indicates feedback (bi-directional causality) between the two variables (P < 0.05), but forcing of aeolian desertification area by population is weak. Meanwhile, we find aeolian desertification area is significantly affected by temperature, as expected. However, there is no obvious forcing for the aeolian desertification area and precipitation. Aeolian desertification area with wind speed indicates feedback (bi-directional causality) between the two variables with significant signal (P < 0.01). We infer that aeolian desertification is greatly affected by natural factors compared with anthropogenic factors. For the desertification in China, we are greatly convinced that desertification prevention is better than control.
Mass spectrometry imaging of biomarker lipids for phagocytosis and signalling during focal cerebral ischaemia
Authors: Nielsen Mette M. B. , Lambertsen Kate L. , Clausen Bettina H. , Meyer Morten , Bhandari Dhaka R. , Larsen Søren T. , Poulsen Steen S. , Spengler Bernhard , Janfelt Christian , Hansen Harald S. 
Published: December 2016

AbstractFocal cerebral ischaemia has an initial phase of inflammation and tissue injury followed by a later phase of resolution and repair. Mass spectrometry imaging (desorption electrospray ionization and matrix assisted laser desorption ionization) was applied on brain sections from mice 2 h, 24 h, 5d, 7d, and 20d after permanent focal cerebral ischaemia. Within 24 h, N-acyl-phosphatidylethanolamines, lysophosphatidylcholine, and ceramide accumulated, while sphingomyelin disappeared. At the later resolution stages, bis(monoacylglycero)phosphate (BMP(22:6/22:6)), 2-arachidonoyl-glycerol, ceramide-phosphate, sphingosine-1-phosphate, lysophosphatidylserine, and cholesteryl ester appeared. At day 5 to 7, dihydroxy derivates of docosahexaenoic and docosapentaenoic acid, some of which may be pro-resolving mediators, e.g. resolvins, were found in the injured area, and BMP(22:6/22:6) co-localized with the macrophage biomarker CD11b, and probably with cholesteryl ester. Mass spectrometry imaging can visualize spatiotemporal changes in the lipidome during the progression and resolution of focal cerebral inflammation and suggests that BMP(22:6/22:6) and N-acyl-phosphatidylethanolamines can be used as biomarkers for phagocytizing macrophages/microglia cells and dead neurones, respectively.
Controlled Orientation of Active Sites in a Nanostructured Multienzyme Complex
Authors: Lim Sung In , Yang Byungseop , Jung Younghan , Cha Jaehyun , Cho Jinhwan , Choi Eun-Sil , Kim Yong Hwan , Kwon Inchan 
Published: December 2016

AbstractMultistep cascade reactions in nature maximize reaction efficiency by co-assembling related enzymes. Such organization facilitates the processing of intermediates by downstream enzymes. Previously, the studies on multienzyme nanocomplexes assembled on DNA scaffolds demonstrated that closer interenzyme distance enhances the overall reaction efficiency. However, it remains unknown how the active site orientation controlled at nanoscale can have an effect on multienzyme reaction. Here, we show that controlled alignment of active sites promotes the multienzyme reaction efficiency. By genetic incorporation of a non-natural amino acid and two compatible bioorthogonal chemistries, we conjugated mannitol dehydrogenase to formate dehydrogenase with the defined active site arrangement with the residue-level accuracy. The study revealed that the multienzyme complex with the active sites directed towards each other exhibits four-fold higher relative efficiency enhancement in the cascade reaction and produces 60% more D-mannitol than the other complex with active sites directed away from each other.
Distribution of Herbivorous Fish Is Frozen by Low Temperature
Authors: Vejříková Ivana , Vejřík Lukáš , Syväranta Jari , Kiljunen Mikko , Čech Martin , Blabolil Petr , Vašek Mojmír , Sajdlová Zuzana , Chung Son Hoang The , Šmejkal Marek , Frouzová Jaroslava , Peterka Jiří 
Published: December 2016

AbstractThe number of herbivores in populations of ectothermic vertebrates decreases with increasing latitude. At higher latitudes, fish consuming plant matter are exclusively omnivorous. We assess whether omnivorous fish readily shift to herbivory or whether animal prey is typically preferred. We address temperature as the key factor causing their absence at higher latitudes and discuss the potential poleward dispersion caused by climate changes. A controlled experiment illustrates that rudd (Scardinius erythrophthalmus) readily utilize plant matter at water temperatures above 20 °C and avoid its consumption below 20 °C. Field data support these results, showing that plant matter dominates rudd diets during the summer and is absent during the spring. Utilizing cellulose requires the enzyme cellulase, which is produced by microorganisms growing at temperatures of 15–42 °C. Water temperatures at higher latitudes do not reach 15 °C year-round; at our latitude of 50°N~150 days/year. Hence, the species richness of omnivorous fish decreases dramatically above 55° latitude. Our results provide support for the hypothesis that strict herbivorous specialists have developed only in the tropics. Temperatures below 15 °C, even for a short time period, inactivate cellulase and cause diet limitations for omnivorous fish. However, we may expect increases in herbivory at higher latitudes caused by climate change.
Formation of amorphous calcium carbonate in caves and its implications for speleothem research
Authors: Demény Attila , Németh Péter , Czuppon György , Leél-Őssy Szabolcs , Szabó Máté , Judik Katalin , Németh Tibor , Stieber József 
Published: December 2016

AbstractSpeleothem deposits are among the most valuable continental formations in paleoclimate research, as they can be dated using absolute dating methods, and they also provide valuable climate proxies. However, alteration processes such as post-depositional mineralogical transformations can significantly influence the paleoclimatic application of their geochemical data. An innovative sampling and measurement protocol combined with scanning and transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy is presented, demonstrating that carbonate precipitating from drip water in caves at ~10 °C contains amorphous calcium carbonate (ACC) that later transforms to nanocrystalline calcite. Stable oxygen isotope fractionations among calcite, ACC and water were also determined, proving that ACC is 18O-depleted (by >2.4 ± 0.8‰) relative to calcite. This, in turn, has serious consequences for speleothem-based fluid inclusion research as closed system transformation of ACC to calcite may induce a negative oxygen isotope shift in fluid inclusion water, resulting in deterioration of the original compositions. ACC formation increases the speleothems’ sensitivity to alteration as its interaction with external solutions may result in the partial loss of original proxy signals. Mineralogical analysis of freshly precipitating carbonate at the studied speleothem site is suggested in order to determine the potential influence of ACC formation.
Reduced host-specificity in a parasite infecting non-littoral Lake Tanganyika cichlids evidenced by intraspecific morphological and genetic diversity
Authors: Kmentová Nikol , Gelnar Milan , Mendlová Monika , Van Steenberge Maarten , Koblmüller Stephan , Vanhove Maarten P. M. 
Published: December 2016

AbstractLake Tanganyika is well-known for its high species-richness and rapid radiation processes. Its assemblage of cichlid fishes recently gained momentum as a framework to study parasite ecology and evolution. It offers a rare chance to investigate the influence of a deepwater lifestyle in a freshwater fish-parasite system. Our study represents the first investigation of parasite intraspecific genetic structure related to host specificity in the lake. It focused on the monogenean flatworm Cichlidogyrus casuarinus infecting deepwater cichlids belonging to Bathybates and Hemibates. Morphological examination of C. casuarinus had previously suggested a broad host range, while the lake’s other Cichlidogyrus species are usually host specific. However, ongoing speciation or cryptic diversity could not be excluded. To distinguish between these hypotheses, we analysed intraspecific diversity of C. casuarinus. Monogeneans from nearly all representatives of the host genera were examined using morphometrics, geomorphometrics and genetics. We confirmed the low host-specificity of C. casuarinus based on morphology and nuclear DNA. Yet, intraspecific variation of sclerotized structures was observed. Nevertheless, the highly variable mitochondrial DNA indicated recent population expansion, but no ongoing parasite speciation, confirming, for the first time in freshwater, reduced parasite host specificity in the deepwater realm, probably an adaptation to low host availability.
Passive immunization with anti-ActA and anti-listeriolysin O antibodies protects against Listeria monocytogenes infection in mice
Authors: Asano Krisana , Sashinami Hiroshi , Osanai Arihiro , Hirose Shouhei , Ono Hisaya K. , Narita Kouji , Hu Dong-Liang , Nakane Akio 
Published: December 2016

AbstractListeria monocytogenes is an intracellular pathogen that causes listeriosis. Due to its intracellular niche, L. monocytogenes has evolved to limit immune recognition and response to infection. Antibodies that are slightly induced by listerial infection are completely unable to protect re-infection of L. monocytogenes. Thus, a role of antibody on the protective effect against L. monocytogenes infection has been neglected for a long time. In the present study, we reported that passive immunization with an excessive amount of antibodies against ActA and listeriolysin O (LLO) attenuates severity of L. monocytogenes infection. Combination of these antibodies improved survival of L. monocytogenes infected mice. Bacterial load in spleen and liver of listerial infected mice and infected RAW264.7 cells were significantly reduced by administration of anti-ActA and anti-LLO antibodies. In addition, anti-LLO antibody neutralized LLO activity and inhibited the bacterial escape from the lysosomal compartments. Moreover, anti-ActA antibody neutralized ActA activity and suppressed actin tail formation and cell-to-cell spread. Thus, our studies reveal that passive immunization with the excessive amount of anti-ActA and -LLO antibodies has potential to provide the protective effect against listerial infection.
The identity of belowground herbivores, not herbivore diversity, mediates impacts on plant productivity
Authors: Milosavljević Ivan , Esser Aaron D. , Bosque-Pérez Nilsa A. , Crowder David W. 
Published: December 2016

AbstractAcross many ecosystems, increases in species biodiversity generally results in greater resource acquisition by consumers. Few studies examining the impacts of consumer diversity on resource capture have focused on terrestrial herbivores, however, especially taxa that feed belowground. Here we conducted field mesocosm experiments to examine the effects of variation in species richness and composition within a community of wireworm herbivores on wheat plant productivity. Our experiments involved wireworm communities consisting of between one and three species, with all possible combinations of species represented. We found that the presence of wireworms reduced plant biomass and seed viability, but wireworm species richness did not impact these plant metrics. Species identity effects were strong, as two species, Limonius californicus and Selatosomus pruininus, had significantly stronger impacts on plants compared to L. infuscatus. Communities with either of the two most impactful species consistently had the greatest impact on wheat plants. The effects of wireworms were thus strongly dependent on the particular species present rather than the overall diversity of the wireworm community. More broadly, our study supports the general finding that the identity of particular consumer species within communities often has greater impacts on ecosystem functioning than species richness.