bluuebunny/crossref_metadata_2025_split huggingface dataset:
­Change of niche in guanaco (Lama guanicoe): The effects of climate change on habitat suitability and lineage conservatism in Chile
Authors: Castillo Andrea G , Alò Dominique , González Benito A , Samaniego Horacio 
Published: January 2018

Background. A fundamental problem in the biogeography of climate change is to understand and predict how environmental factors determine whether organisms will alter their seasonal activities, home ranges, migratory patterns, abundances, and interspecific interactions. The main goal of this contribution was to define the ecological niche of the guanaco (Lama guanicoe) to describe potential distributional changes and to assess the relative importance of niche conservatism and divergence processes among the two lineages described for the species.
Methods. We used current and future projections of climate change under two extreme GHG emission scenarios (RCP2.6 and RCP8.5) to evaluate changes of the environmental niche and future distribution of the largest mammal in the southern cone of South America. Evaluation of niche conservatism and divergence are based on identity and background similarity tests.
Results. We show that: a) the current geographic distribution of lineages and contact population prescribe different climatic requirements that are related to the geographic areas where these lineages are located; b) future distribution models predict a decrease in the distribution surface under both scenarios; c) the surface area predicted to be gained, lost, and unchanged is ~15%, 15- 26%, and 85- 75% respectively; d) a 3% increase of areal protection is expected if the current distribution of protected areas is maintained, however this is expected to occur at the expense of a large reduction of high quality habitats under the best scenario and; e) current and future distribution ranges of guanaco mostly adhere to phylogenetic niche divergence hypotheses between linages (L. g. cacsilensis and L. g. guanicoe). However, both lineages and the contact population show niche conservatism given niche similarity tests.
Discussion. Associating environmental variables to species ecological niche seem to be an important aspect of unveiling the particularities of, both, evolutionary patterns and ecological features that species face in a changing environment. We have provided specific descriptions of how such patterns may play out under the most extreme climate change predictions, thereby, providing a grim outlook of the future potential distribution of guanaco. From an ecological perspective, while a slightly larger distribution area is expected, this may come with an important reduction of available quality habitats. From the evolutionary perspective, we describe the limitations of the contact population´s niche to merge with the northern and/or southern niche lineages of guanaco exposing the complexities of understanding evolutionary patterns across this taxon as it experiences climate change dynamics.
Annual and spatial variation in composition and activity of terrestrial mammals on two replicate plots in lowland forest of eastern Ecuador
Authors: Blake John G. , Loiselle Bette A. 
Published: January 2018

Terrestrial mammals are important components of lowland forests in Amazonia (as seed dispersal agents, herbivores, predators) but there are relatively few detailed studies from areas that have not been affected by human activities (e.g., hunting, logging). Yet, such information is needed to evaluate effects of humans elsewhere. We used camera traps to sample medium to large-sized terrestrial mammals at a site in lowland forests of eastern Ecuador, one of the most biologically rich areas in the world. We deployed cameras on two study plots interra firmeforest at Tiputini Biodiversity Station. Sixteen cameras were arranged 200 m apart in a 4 × 4 grid on each plot. Cameras were operated for 60 days in January–March, 2014–2017, for a total of 3,707 and 3,482 trap-days on the two plots (Harpia, Puma). A total of 28 species were recorded; 26 on Harpia and 25 on Puma. Number of species recorded each year was slightly greater on Harpia whereas overall capture rates (images/100 trap-days) were higher on Puma. Although most species were recorded on each plot, differences in capture rates meant that yearly samples on a given plot were more similar to each other than to samples on the other plot. Images of most species showed a clumped distribution pattern on each plot;Panthera oncawas the only species that did not show a clumped distribution on either plot. Images at a given camera location showed no evidence of autocorrelation with numbers of images at nearby camera locations, suggesting that species were responding to small-scale differences in habitat conditions. A redundancy analysis showed that environmental features within 50 or 100 m of camera locations (e.g., elevation, variation in elevation, slope, distance to streams) accounted for significant amounts of variation in distribution patterns of species. Composition and relative importance based on capture rates were very similar to results from cameras located along trails at the same site; similarities decreased at increasing spatial scales based on comparisons with results from other sites in Ecuador and Peru.
Tropical Cyclone Activity in the High‐Resolution Community Earth System Model and the Impact of Ocean Coupling
Authors: Li Hui , Sriver Ryan L. 
Published: January 2018

AbstractHigh‐resolution Atmosphere General Circulation Models (AGCMs) are capable of directly simulating realistic tropical cyclone (TC) statistics, providing a promising approach for TC‐climate studies. Active air‐sea coupling in a coupled model framework is essential to capturing TC‐ocean interactions, which can influence TC‐climate connections on interannual to decadal time scales. Here we investigate how the choices of ocean coupling can affect the directly simulated TCs using high‐resolution configurations of the Community Earth System Model (CESM). We performed a suite of high‐resolution, multidecadal, global‐scale CESM simulations in which the atmosphere (∼0.25° grid spacing) is configured with three different levels of ocean coupling: prescribed climatological sea surface temperature (SST) (ATM), mixed layer ocean (SLAB), and dynamic ocean (CPL). We find that different levels of ocean coupling can influence simulated TC frequency, geographical distributions, and storm intensity. ATM simulates more storms and higher overall storm intensity than the coupled simulations. It also simulates higher TC track density over the eastern Pacific and the North Atlantic, while TC tracks are relatively sparse within CPL and SLAB for these regions. Storm intensification and the maximum wind speed are sensitive to the representations of local surface flux feedbacks in different coupling configurations. Key differences in storm number and distribution can be attributed to variations in the modeled large‐scale climate mean state and variability that arise from the combined effect of intrinsic model biases and air‐sea interactions. Results help to improve our understanding about the representation of TCs in high‐resolution coupled Earth system models, with important implications for TC‐climate applications.
Direct Breakthrough Curve Prediction From Statistics of Heterogeneous Conductivity Fields
Authors: Hansen Scott K. , Haslauer Claus P. , Cirpka Olaf A. , Vesselinov Velimir V. 
Published: January 2018

AbstractThis paper presents a methodology to predict the shape of solute breakthrough curves in heterogeneous aquifers at early times and/or under high degrees of heterogeneity, both cases in which the classical macrodispersion theory may not be applicable. The methodology relies on the observation that breakthrough curves in heterogeneous media are generally well described by lognormal distributions, and mean breakthrough times can be predicted analytically. The log‐variance of solute arrival is thus sufficient to completely specify the breakthrough curves, and this is calibrated as a function of aquifer heterogeneity and dimensionless distance from a source plane by means of Monte Carlo analysis and statistical regression. Using the ensemble of simulated groundwater flow and solute transport realizations employed to calibrate the predictive regression, reliability estimates for the prediction are also developed. Additional theoretical contributions include heuristics for the time until an effective macrodispersion coefficient becomes applicable, and also an expression for its magnitude that applies in highly heterogeneous systems. It is seen that the results here represent a way to derive continuous time random walk transition distributions from physical considerations rather than from empirical field calibration.
Pyrolytically Modified Polyacrylonitrile‐Covalently Grafted MoS2 Nanosheets for a Nonvolatile Rewritable Memory Device
Authors: Fan Fei , Zhang Bin , Song Sannian , Liu Bo , Cao Yaming , Chen Yu 
Published: January 2018

AbstractThe electrical conductivity of laterally ordered polyacrylonitrile (PAN) can be improved by pyrolytic modification. Newly synthesized MoS2 nanosheets covalently grafted with PAN (MoS2‐PAN) do not exhibit any electrical switching and memory effect in an indium tin oxide (ITO)/MoS2‐PAN/Au device under applied bias voltages. After annealing at 220 °C for 4 h, the resultant pyrolytically modified product “pyro‐MoS2‐PAN” shows good nonvolatile rewritable memory performance, with a large ON/OFF current ratio of 4 × 104 and lower switching on and off voltages of −1.09 and 1.24 V. Highly reproducible memory I–V loops of more than 60 consecutive cycles are achieved without clear degradation of the ON and OFF states. The first oxidation potential of pyro‐MoS2‐PAN is cathodically shifted to over 530 mV lower than that of MoS2‐PAN, indicating the higher hole injection of pyro‐MoS2‐PAN when compared to MoS2‐PAN. As expected, the nonannealed MoS2/PAN blend‐based device does not show any memory effect under the same experimental condition. After annealing at 220 °C for 4 h, the blends exhibit unstable electrical switching and rewritable memory performance.
Utilization of Donor–Acceptor Interactions for the Catalytic Acceleration of Nucleophilic Additions to Aromatic Carbonyl Compounds
Authors: Uchikura Tatsuhiro , Ono Kosuke , Takahashi Kohei , Iwasawa Nobuharu 
Published: January 2018

AbstractA conceptually new method for the catalytic electrophilic activation of aromatic carbonyl substrates, by utilizing donor–acceptor interactions between an electron‐deficient macrocyclic boronic ester host ([2+2]BTH‐F) and an aromatic carbonyl guest substrate, was realized. In the presence of a catalytic amount of [2+2]BTH‐F, dramatic acceleration of the nucleophilic addition of a ketene silyl acetal towards either electron‐rich aromatic aldehydes or ketones was achieved. Several control experiments confirmed that inclusion of the aromatic substrates within [2+2]BTH‐F, through efficient donor–acceptor interactions, is essential for the acceleration of the reaction.
Single fiber peel test to assess ultra high molecular weight polyethylene fiber mesostructure interactions
Authors: McDaniel Preston B. , Deitzel Joseph M. , Gregory Domenick , Polakovic Timothy , Gillespie John W. 
Published: January 2018

ABSTRACTIn this work, a variable angle, single fiber peel test is developed to analyze the effects of fiber structure on the mixed mode failure within ultra high molecular weight polyethylene fibers. The Mode I and Mode II peel energy release rates are quantified and the effects of fiber meso/nanostructure on these modes are examined. Comparison of the load‐extension curves from the peel test with in‐situ video, and post‐mortem analysis using high‐resolution microscopy techniques indicates that Mode I and Mode II splitting are both significantly influenced by the deformation of nanoscale fibrils within a mesoscale network. The fibrils in the network are placed in tension across the peel/shear interface resulting in elevated values of peel energy release rates with an increasing number of engaged fibrils. The number of engaged fibrils is shown to increase with decreasing peel angle and increasing Mode II failure contribution. A bi‐linear mixed‐mode failure criterion is established. The results, and analysis of the fiber structure are discussed in context of their implications for load pathways in the fiber. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46156.
Scalable Preparation of Photochromic Composite Foils with Excellent Reversibility for Light Printing
Authors: Zhou Yijie , Huang Aibing , Ji Shidong , Zhou Huaijuan , Jin Ping , Li Rong 
Published: January 2018

AbstractPhotochromic inks for repeatable light‐printed media have attracted increasing attention owing to the fact that they may be widely applied to reduce the consumption of papers and plastics and conserve the environment. Therefore, it is of practical significance to develop convenient photochromic inks with a low cost and on a large scale. In this study, a simple one‐step hydrothermal route was used to prepare tungsten trioxide (WO3) nanoparticles, which were further used to make photochromic inks and transparent photochromic films. The obtained transparent photochromic film could rapidly respond to UV light within tens of seconds, then return to its initial state, with different recovery times at different temperatures, and also exhibit good reversible coloration–bleaching effect. A typical polyethylene terephthalate (PET) foil coated with the photochromic ink could also be repeatedly printed with various patterns and displayed excellent rewritable performance over tens of cycles. This study proposes a simple method for widespread applications of WO3‐based photochromic inks.
Full analytical evaluation of the line shift and line width of ions in solids for Raman processes
Authors: Eser Erhan , Koç Hüseyin 
Published: January 2018

AbstractIn this paper, we present a new analytical method to evaluate the temperature dependence of the thermal line shift and thermal line width of spectral lines in the Raman process using a simple approximation for the Debye functions. The proposed formulae guarantee the accurate and fast calculation of the thermal line shift and thermal line width. As an example of application, the analytical expression obtained is used to calculate the line shift and line width of the 2E → 4A2 transitions in V2+:MgO at temperatures from 0 K up to 500 K. This analytical evaluation shows that our results are satisfactory for the wide range temperature variations.
Giant genital warts
Authors: Georgopoulos Ioannis , Nastos Constantinos , Dellis Athanasios 
Published: January 2018

Key Clinical MessageGenital warts are quite common and should be treated early with nonaggressive conservative or invasive methods. When they are severely neglected patients may be submitted to amputative surgical management. Preoperatively malignant transformation of the tumors cannot be excluded.
Monitoring the Spin States of Ferrous Ions by Fluorescence Spectroscopy in Spin‐Crossover–Fluorescent Hybrid Materials
Authors: Wang Chun‐Feng , Yang Guo‐Yu , Yao Zi‐Shuo , Tao Jun 
Published: January 2018

AbstractThe grafts of fluorophores 9‐anthraldehyde (AD) and 9‐phenanthrenecarboxaldehyde (PD), respectively, on the one‐dimensional spin‐crossover compound [Fe(L)3](ClO4)2 (FeL, L=4‐amino‐1,2,4‐triazole) by post‐synthetic aldimine condensation reactions produced two spin‐crossover (SCO)–fluorescent hybrid materials, that is, FeL‐AD and FeL‐PD. The spin‐crossover critical temperatures of the two materials both centered at Tc↓=254 and Tc↑=256 K, whereas the fluorescence intensities of the two materials featured functions of the temperature that strictly synchronized with the spin‐crossover processes, which showed that the ligand‐centered fluorescence was dominated by the spin states of the ferrous ions. The bifunctional entities (spin‐crossover centers and fluorophores) in FeL‐AD or FeL‐PD showed spectral band overlap that purported the Förster resonance energy transfer mechanism of such spin‐crossover–fluorescence correlation. The post‐synthetic modification of SCO materials and the relationship between the fluorescence and the SCO may be helpful in the development of multifunctional materials that can be sensitive to multiple stimuli.
Ion Selectivity in Nonpolymeric Thermosensitive Systems Induced by Water‐Attenuated Supramolecular Recognition
Authors: Qi Zhenhui , Chiappisi Leonardo , Gong Hanlin , Pan Ren , Cui Ning , Ge Yan , Böttcher Christoph , Dong Shengyi 
Published: January 2018

AbstractThe chemistry of aqueous salt solutions is rich with ambiguities, especially in stimuli‐responsive supramolecular systems. Rational use of ion specificity to design supramolecular responsive materials, however, remains a challenging task. In this work, a low‐molecular‐weight supramolecular system was developed that was used to reveal the underlying systematic relationship between ions, water, and solutes. By utilizing these water‐attenuated supramolecular forces (with Ka only ca. 30 m−1), an alternative concept for fabricating an aqueous responsive system in ionic medium was demonstrated. This work not only provides mechanistic insight into the underdeveloped role of topology in ion specificity upon noncharged polar surfaces, but also demonstrates the feasibility of utilizing weak supramolecular approaches to control the thermoresponsiveness.
Ground State versus Excited State: Discrepancy in Electronic Communication in a Series of meso–meso Two‐Atom‐Bridged Diporphyrins
Authors: Zieleniewska Anna , Harper Shannon R. , Arnold Dennis P. , Guldi Dirk M. 
Published: January 2018

AbstractThe focal point of this work is the photophysical characterization of three meso–meso two‐atom‐bridged diporphyrins. Detailed investigations by means of cyclic voltammetry, absorption, fluorescence, and femto‐/nanosecond transient absorption spectroscopy revealed the discrepancy in electronic communication in a series of meso–meso two‐atom‐bridged porphyrins in the ground state and in the excited state. In the ground state, the azo bridge facilitates the strongest electronic communication between the two porphyrins. In the excited state, however, the ethene bridge induces the strongest coupling, followed by the imine and azo bridges.
Catalyst‐ and Initiator‐Free Radical Addition under Mild Conditions: A Macromolecular Conjugation Tool
Authors: Autissier Laurent , Mabrouk Kamel , Chendo Christophe , Guillaneuf Yohann , Rollet Marion , Charles Laurence , Gigmes Didier , Trimaille Thomas 
Published: January 2018

AbstractA catalyst/initiator‐free radical addition reaction performed under mild conditions (water, 30 °C) with high yields is reported for the first time. This reaction implies simple pH‐mediated alkoxyamine dissociation followed by addition onto olefinic substrates. The versatility and relevance of this selective reaction for macromolecular conjugation and engineering are shown through the syntheses of block copolymers, as well as hydrogels containing in situ‐loaded proteins, which could retain biological activity. This contrasts with standard thermal radical conditions that lead to complete protein inactivation.
Versatile Organic Chemistry on Vanadium‐Based Multi‐Electron Reservoirs
Authors: Nachtigall Olaf , Spandl Johann 
Published: January 2018

AbstractWe report the synthesis, post‐functionalization, and redox behavior of two organically functionalized aggregates, [V6O7(OMe)9{(OCH2)3C−CH2N3}] and [V6O7(OMe)9{(OCH2)3C−NH2}]. All twelve μ2‐oxo groups on the edges of the Lindqvist‐type {V6O19} core were replaced by alkoxo ligands. The absence of a negative charge and the closed organic shell make these neutral mixed‐valence compounds very stable towards hydrolysis and well soluble in almost all common organic solvents. These are important advantages over classical POMs. By post‐functionalization through copper(I)‐catalyzed Huisgen cycloaddition or imine formation, various organic moieties could be introduced. Even a well‐soluble trimer composed of three hexanuclear vanadium units connected through an aromatic triimino core was synthesized and studied. The diverse redox behavior, the versatile reactivity, the good stability, and the excellent solubility make our vanadium compounds highly interesting for applications as building blocks in macromolecular chemistry as well as redox labels in biochemistry.
Novel In Situ Magnetic Separator for Magnetic Particle‐Based Enzyme Purification or Biocatalysis
Authors: Shaikh Yonas S. , Seibert Christian , Kampeis Percy 
Published: January 2018

AbstractA novel in situ magnetic separator is presented in which the separation unit is directly mounted on the bioreactor. Therefore, it is possible to collect the magnetic particles directly from the reaction liquid and transfer them in one step sterile out of the reactor. By consecutive flushing, the particles are concentrated and separated from the rest. The operating parameters were determined and evaluated experimentally and by computational fluid dynamics. The separator was tested in combination with a 5‐L bioreactor with glass flask. Hereby, the accumulation kinetics of the particles were analyzed and used for a simple theoretical model.
Methylation of Tcf712 promoter by high‐fat diet impairs β‐cell function in mouse pancreatic islets
Authors: Hu Yun , Shi Ping , He Ke , Zhu Yun‐qing , Yang Fan , Yang Min , He Bang‐Shun , Mao Xiao‐Ming 
Published: January 2018

AbstractBackgroundThe TCF7L2 (transcription factor 7 like 2) gene is strongly associated with type 2 diabetes risk. However, many people without the TCF7L2 at‐risk allele develop T2D. The aim of this study was to investigate altered Tcf7l2 DNA methylation and gene expression caused by high‐fat diets (HFDs).MethodsC57BL/6 mice were fed either an HFD or normal diet for 8 weeks, and intraperitoneal glucose tolerance tests were performed. Pancreatic islets were sorted for bisulfite sequencing polymerase chain reaction to determine DNA methylation status. We cloned the Tcf7l2 promoter, methylated it with methyltransferase, and transfected this construct into MIN‐6 cells to confirm the effects of promoter methylation on Tcf7l2 expression.ResultsAberrant methylation at position −165 bp relative to the transcriptional start site of Tcf7l2 was present in mice fed an HFD. Accordingly, expression of Tcf7l2 mRNA and its corresponding protein was lower in the HFD group (P < .05). Methylation of the Tcf7l2 promoter suppressed gene expression in MIN‐6 cells.ConclusionAn HFD was shown to induce aberrant methylation of the Tcf7l2 promoter in mouse islets, which resulted in diminished gene expression. This study provides an evidence of the association between nutrient consumption and gene expression.
New frontiers in RNA transport and local translation in neurons
Authors: Van Driesche Sarah J. , Martin Kelsey C. 
Published: January 2018

ABSTRACTRNA localization to neuronal dendrites and axons is increasingly recognized as a significant and widespread mechanism of gene expression control in neurons. High‐throughput RNA sequencing is rapidly expanding the universe of known localized mRNAs. Although there are inherent difficulties in preparing sequencing libraries from dendrites and axons in the context of intact brain, genetic labeling strategies have paved the way for improved studies of this type. As the list of localized mRNAs grows, there is increasing need for functional validation of localized transcripts—that is, do particular localized transcripts serve demonstrable physiologic functions in axons or dendrites? Finally, specific details about what localized mRNAs do once they reach distal processes have long been elusive. Recent work using single‐molecule imaging and other techniques is starting to fill in the picture of how transcripts navigate the localized environment and undergo activity‐dependent translational de‐repression. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 331–339, 2018