bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative chemometric analysis for classification of acids and bases via a colorimetric sensor array
Authors: Kangas Michael J. , Burks Raychelle M. , Atwater Jordyn , Lukowicz Rachel M. , Garver Billy , Holmes Andrea E. 
Published: October 2017

AbstractWith the increasing availability of digital imaging devices, colorimetric sensor arrays are rapidly becoming a simple, yet effective tool for the identification and quantification of various analytes. Colorimetric arrays utilize colorimetric data from many colorimetric sensors, with the multidimensional nature of the resulting data necessitating the use of chemometric analysis. Herein, an 8 sensor colorimetric array was used to analyze select acid and basic samples (0.5 – 10 M) to determine which chemometric methods are best suited for classification quantification of analytes within clusters.PCA, HCA, and LDA were used to visualize the data set. All three methods showed well‐separated clusters for each of the acid or base analytes and moderate separation between analyte concentrations, indicating that the sensor array can be used to identify and quantify samples. Furthermore, PCA could be used to determine which sensors showed the most effective analyte identification. LDA, KNN, and HQI were used for identification of analyte and concentration. HQI and KNN could be used to correctly identify the analytes in all cases, while LDA correctly identified 95 of 96 analytes correctly. Additional studies demonstrated that controlling for solvent and image effects was unnecessary for all chemometric methods utilized in this study.
Bonding Scheme and Optical Properties in BiM2O2(PO4) (M=Cd, Mg, Zn); Experimental and Theoretical Analysis
Authors: Olchowka J. , Mentré O. , Kabbour H. , Colmont M. , Adlung M. , Suta M. , Wickleder C. 
Published: October 2017

AbstractLuminescence properties of the Bi(M,M′)2PO6 (M=Mg, Zn, Cd) series have been rationalized as a function of the M element using optical spectroscopy, as well as empirical and first principles calculations. The latter yielded indirect band gaps for all compounds with energies between 2.64 and 3.62 eV, whereas luminescence measurements exhibit bright warm white emission luminescence even at room temperature assigned to Bi3+ transitions with, for example, 22.8 % quantum yield for M=Mg. The energies of the excitation maxima are shifted with the covalent character of the Bi−O bond by inductive effects of the neighboring M−O bonds. This is discussed on the basis of empirical and electronic structure calculations. Strikingly, in all the investigated compounds, an excitation process occurring at energies higher than the band gaps is observed, which seems to be intrinsic to the s2→sp electronic transitions of the Bi3+ ions. Concerning the emission process, a direct correlation between the lone pair (LP) activity and the emission energy upon change of the lattice parameters was established governing the LP stereo‐activity in the BiMg2‐xCdxPO6 system. As a result, the possibility for tunable optical properties appears realistic in the Bi2O3‐MO‐X2O5 (X=P, V, As, etc.) systems taking into account the diversity of reported or novel crystal structures that can be designed using well‐established rules of crystal chemistry.
The Synergistic Effect between Triphenylpyrrole Isomers as Donors, Linking Groups, and Acceptors on the Fluorescence Properties of D–π–A Compounds in the Solid State
Authors: Lei Yunxiang , Lai Yueyin , Dong Lichao , Shang Guojun , Cai Zhengxu , Shi Jianbing , Zhi Junge , Li Pengfei , Huang Xiaobo , Tong Bin , Dong Yuping 
Published: October 2017

AbstractEight donor–π–acceptor (D–π–A) compounds employing triphenylpyrrole isomers (TPP‐1,2,5 and TPP‐1,3,4) as donors, malononitrile (CN) and 1H‐indene‐1,3(2H)‐dione (CO) as acceptors, pyridone (P) and benzopyran (B) as π‐linking groups were synthesized. The compounds exhibited aggregation‐induced emission and piezochromic properties. Compared with previously reported donors, triphenylpyrroles induced all the compounds to have more remarkable photophysical properties. The compounds containing TPP‐1,2,5 and P moieties displayed stronger fluorescence intensities, shorter emission wavelengths, and more distinct piezochromic properties. However, the same phenomenon was observed in the TPP‐1,3,4‐containing system if B was as π‐linker. Moreover, the CN acceptor endowed the compound to have a relatively strong fluorescent intensity, in which CO induced a relatively long emission wavelength. That is, the photophysical properties of D–π–A compounds can be controlled by adjusting the structure of donor, linker and acceptor.
Electron‐Proton Transfer Mechanism of Excited‐State Hydrogen Transfer in Phenol‐(NH3)n (n=3 and 5)
Authors: Miyazaki Mitsuhiko , Ohara Ryuhei , Dedonder Claude , Jouvet Christophe , Fujii Masaaki 
Published: October 2017

AbstractExcited‐state hydrogen transfer (ESHT) is responsible for various photochemical processes of aromatics, including photoprotection of nuclear basis. Its mechanism is explained by internal conversion from the aromatic ππ* to πσ* states via conical intersection. This means that the electron is transferred to a diffuse Rydberg‐like σ* orbital apart from proton migration. This picture means the electron and the proton do not move together and the dynamics are different in principle. Here, we have applied picosecond time‐resolved near‐infrared (NIR) and infrared (IR) spectroscopy to the phenol‐(NH3)5 cluster, the benchmark system of ESHT, and monitored the electron transfer and proton motion independently. The electron transfer monitored by the NIR transition rises within 3 ps, while the overall H transfer detected by the IR absorption of NH vibration appears with a lifetime of about 20 ps. This clearly proves that the electron motion and proton migration are decoupled. Such a difference of the time‐evolutions between the NIR absorption and the IR transition has not been detected in a cluster with three ammonia molecules. We will report our full observation together with theoretical calculations of the potential energy surfaces of the ππ* and πσ* states, and will discuss the ESHT mechanism and its cluster size‐dependence between n=3 and 5. It is suggested that the presence and absence of a barrier in the proton transfer coordinate cause the different dynamics.
N‐Doped Carbon Nanofibrous Network Derived from Bacterial Cellulose for the Loading of Pt Nanoparticles for Methanol Oxidation Reaction
Authors: Yuan Fanshu , Huang Yang , Fan Mengmeng , Chen Chuntao , Qian Jieshu , Hao Qingli , Yang Jiazhi , Sun Dongping 
Published: October 2017

AbstractThe large‐scale, low‐cost preparation of Pt‐based catalysts with high activity and durability for the methanol oxidation reaction is still challenging. The key to achieving this aim is finding suitable supporting materials. In this paper, N‐doped carbon nanofibrous networks are prepared by annealing a gel containing two inexpensive and ecofriendly precursors, that is, bacterial cellulose and urea, for the loading of Pt nanoparticles. An undoped analogue is also prepared for comparison. Meanwhile, the effect of the annealing temperature on the performance of the catalysts is evaluated. The results show that the N doping and higher annealing temperature can improve the electron conductivity of the catalyst and provide more active sites for the loading of ultrafine Pt nanoparticles with a narrow size distribution. The best catalyst exhibits a remarkably high electrocatalytic activity (627 mA mg−1), excellent poison tolerance, and high durability. This work demonstrates an ideal Pt supporting material for the methanol oxidation reaction.
Reversible Oxidative Se−Se Coupling of Phosphine Selenides by Ph3Sb(OTf)2
Authors: Poller Maximilian J. , Burford Neil , Karaghiosoff Konstantin 
Published: October 2017

AbstractSalts of diphosphoniumdiselenide dications ([R3PSeSePR3][OTf]2) have been isolated from reactions of trialkylphosphine selenides with triphenylantimony bistriflate. The redox process is speculated to proceed via a cationic coordination complex [Ph3SbL2][OTf]2 (L=Me3PSe, iPr3PSe), which is also formed in the reaction of [R3PSeSePR3][OTf]2 with Ph3Sb. The observations indicate that the reductive elimination of [R3PSeSePR3]2+ from [Ph3Sb(SePR3)2]2+ is reversible through the oxidative addition of [R3PSeSePR3]2+ to Ph3Sb.
Unravelling the Redox‐catalytic Behavior of Ce4+ Metal–Organic Frameworks by X‐ray Absorption Spectroscopy
Authors: Smolders Simon , Lomachenko Kirill A. , Bueken Bart , Struyf Arnaud , Bugaev Aram L. , Atzori Cesare , Stock Norbert , Lamberti Carlo , Roeffaers Maarten B. J. , De Vos Dirk E. 
Published: October 2017

AbstractThe introduction of Ce4+ as a structural cation has been shown to be a promising route to redox active metal–organic frameworks (MOFs). However, the mechanism by which these MOFs act as redox catalysts remains unclear. Herein, we present a detailed study of the active site in [Ce6O4(OH)4]‐based MOFs such as Ce‐UiO‐66, involved in the aerobic oxidation of benzyl alcohol, chosen as a model redox reaction. X‐ray absorption spectroscopy (XAS) data confirm the reduction of up to one Ce4+ ion per Ce6 cluster with a corresponding outwards radial shift due to the larger radius of the Ce3+ cation, while not compromising the structural integrity of the framework, as evidenced by powder X‐ray diffraction. This unambiguously demonstrates the involvement of the metal node in the catalytic cycle and explains the need for 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) as a redox mediator to bridge the gap between the one‐electron oxidation of the Ce4+/Ce3+ couple and the two‐electron alcohol oxidation. Finally, an improved catalytic system with Ce‐MOF‐808 and TEMPO was developed which outperformed all other tested Ce4+‐MOFs.
Corrective emotional experience in an integrative affect‐focused therapy: Building a preliminary model using task analysis
Authors: Nakamura Kaori , Iwakabe Shigeru 
Published: October 2017

AbstractObjectiveThe present study constructed a preliminary process model of corrective emotional experience (CEE) in an integrative affect‐focused therapy.MethodTask analysis was used to analyse 6 in‐session events taken from 6 Japanese clients who worked with an integrative affect‐focused therapist. The 6 events included 3 successful CEEs and 3 partially successful CEEs for comparison.ResultsA rational–empirical model of CEE was generated, which consisted of two parallel client change processes, intrapersonal change and interpersonal change, and the therapist interventions corresponding to each process. Therapist experiential interventions and therapist affirmation facilitated both intrapersonal and interpersonal change processes, whereas his relational interventions were associated with the interpersonal change process. The partially successful CEEs were differentiated by the absence of the component of core painful emotions or negative beliefs in intrapersonal change process, which seemed crucial for the interpersonal change process to develop.ConclusionsCEE is best represented by a preliminary model that depicts two parallel yet interacting change processes. Intrapersonal change process is similar to the sequence of change described by the emotional processing model (Pascual‐Leone & Greenberg, ), whereas interpersonal change process is a unique contribution of this study. Interpersonal change process was facilitated when the therapist's active stance and use of immediacy responses to make their relational process explicit allowed a shared exploration. Therapist affirmation bridged intrapersonal change to interpersonal change by promoting an adaptive sense of self in clients and forging a deeper emotional connection between the two.
Feces nitrogen release induced by different large herbivores in a dry grassland
Authors: Wang Jingzhi , Wang Deli , Li Chunqiang , Seastedt Timothy R. , Liang Cunzhu , Wang Ling , Sun Wei , Liang Maowei , Li Yu 
Published: October 2017

AbstractLarge herbivores have pronounced effects on nutrient cycling in grasslands. These organisms are known to alter the quality and quantity of plant production as well as the amounts and quality of plant litter and animal wastes. The generalization that the relative quality of detritus inputs is enhanced by herbivores is well known, but how this process is affected by diet selection processing and feces production of different large herbivores remains largely unstudied. Here, we measured how these differences for cattle and sheep on a dry grassland might influence nitrogen (N) mineralization from feces. We found that cattle of larger body size tended to select the low quality grass Stipa grandis as their major food source. In contrast, the subdominant grass Leymus chinensis, with relatively high N content, was a majority in the diet of smaller sheep, when palatable forbs were insufficient in the field. This diverse diet quality resulted in a C:N ratio of cattle feces that was higher than that of sheep feces. Relatively higher labile C availability in the cattle feces, namely relatively higher cellulose/hemicellulose contents, promoted microbial growth and in turn accelerated cattle feces decomposition. A surprise finding was that the feces from cattle mineralized about twice as much N as feces from sheep, despite the latter having slightly higher N content. From a grassland productivity perspective, increasing the proportion of large body‐sized species in grazing herbivore assemblages perhaps is beneficial to forage productivity and nutrient recycling by the rapid degradation of feces.
Trait–fitness relationships determine how trade‐off shapes affect species coexistence
Authors: Ehrlich Elias , Becks Lutz , Gaedke Ursula 
Published: October 2017

AbstractTrade‐offs between functional traits are ubiquitous in nature and can promote species coexistence depending on their shape. Classic theory predicts that convex trade‐offs facilitate coexistence of specialized species with extreme trait values (extreme species) while concave trade‐offs promote species with intermediate trait values (intermediate species). We show here that this prediction becomes insufficient when the traits translate non‐linearly into fitness which frequently occurs in nature, e.g., an increasing length of spines reduces grazing losses only up to a certain threshold resulting in a saturating or sigmoid trait‐fitness function. We present a novel, general approach to evaluate the effect of different trade‐off shapes on species coexistence. We compare the trade‐off curve to the invasion boundary of an intermediate species invading the two extreme species. At this boundary, the invasion fitness is zero. Thus, it separates trait combinations where invasion is or is not possible. The invasion boundary is calculated based on measurable trait–fitness relationships. If at least one of these relationships is not linear, the invasion boundary becomes non‐linear, implying that convex and concave trade‐offs not necessarily lead to different coexistence patterns. Therefore, we suggest a new ecological classification of trade‐offs into extreme‐favoring and intermediate‐favoring which differs from a purely mathematical description of their shape. We apply our approach to a well‐established model of an empirical predator–prey system with competing prey types facing a trade‐off between edibility and half‐saturation constant for nutrient uptake. We show that the survival of the intermediate prey depends on the convexity of the trade‐off. Overall, our approach provides a general tool to make a priori predictions on the outcome of competition among species facing a common trade‐off in dependence of the shape of the trade‐off and the shape of the trait–fitness relationships.
Morphodynamic assessment of side channel systems using a simple one‐dimensional bifurcation model and a comparison with aerial images
Authors: van Denderen R. Pepijn , Schielen Ralph M. J. , Blom Astrid , Hulscher Suzanne J. M. H. , Kleinhans Maarten G. 
Published: October 2017

AbstractSide channel construction is a common intervention applied to increase a river's conveyance capacity and to increase its ecological value. Past modelling efforts suggest two mechanisms affecting the morphodynamic change of a side channel: (1) a difference in channel slope between the side channel and the main channel and (2) bend flow just upstream of the bifurcation. The objective of this paper was to assess the conditions under which side channels generally aggrade or degrade and to assess the characteristic timescales of the associated morphological change. We use a one‐dimensional bifurcation model to predict the development of side channel systems and the characteristic timescale for a wide range of conditions. We then compare these results to multitemporal aerial images of four side channel systems. We consider the following mechanisms at the bifurcation to be important for side channel development: sediment diversion due to the bifurcation angle, sediment diversion due to the transverse bed slope, partitioning of suspended load, mixed sediment processes such as sorting at the bifurcation, bank erosion, deposition due to vegetation, and floodplain sedimentation. There are limitations to using a one‐dimensional numerical model as it can only account for these mechanisms in a parametrized manner, but the model reproduces general behaviour of the natural side channels until floodplain‐forming processes become important. The main result is a set of stability diagrams with key model parameters that can be used to assess the development of a side channel system and the associated timescale, which will aid in the future design and maintenance of side channel systems. ©  2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.
Tracking capybara (Hydrochoerus hydrochaeris) feces contribution method in aquatic environments using sterols
Authors: Machado Karina Scurupa , Froehner Sandro , Rizzi Juliane , Torres Mayara 
Published: October 2017

Abstract

The monitoring of fecal contamination (human and animal) is an incessant challenge. In this approach, microbiological methods play an important role, though with substantial limitations. Organic compounds, such as sterols, are often used to trace fecal contamination. Although the fecal sterols profiles of some animals are already known, capybara, a typical mammal from South America, is a significant contributor to aquatic fecal contamination because of its water dependence; and still there is no one way, scientifically speaking, to trace its fecal contribution. The aim of the present study was to provide a tool to measure the temporal fecal contribution of capybara in aquatic systems. We examined the sterol content of capybara feces and compared with another species (sheep, cow, horse, pig, hen, duck, cat, dog, opossum, and human). From numerical relationships among fecal sterols, 6 ratios were delineated and tested to assess their potential to identify the capybara feces contribution in contaminated environments. Statistical analysis showed that 3 ratios were able to differentiate capybara feces from other sources. Such ratios were applied in samples of a sediment core from an urban area in south Brazil with a large capybara population. The temporal trend showed a significant contribution of capybara feces in the last 100 yr. Environ Toxicol Chem 2018;37:353–361. © 2017 SETAC
Occasional, obligatory, and habitual stone tool use in hominin evolution
Authors: Shea John J. 
Published: October 2017

AbstractArcheologists have long assumed that earlier hominins were obligatory stone tool users. This assumption is deeply embedded in traditional ways of describing the lithic record. This paper argues that lithic evidence dating before 1.7 Ma reflects occasional stone tool use, much like that practiced by nonhuman primates except that it involved flaked‐stone cutting tools. Evidence younger than 0.3 Ma is more congruent with obligatory stone tool use, like that among recent humans. The onset of habitual stone tool use at about 1.7 Ma appears correlated with increased hominin logistical mobility (carrying things). The onset of obligatory stone tool use after 0.3 Ma may be linked to the evolution of spoken language. Viewing the lithic evidence dating between 0.3‐1.7 Ma as habitual stone tool use explains previously inexplicable aspects of the Early‐Middle Pleistocene lithic record.
How effective and fair is user fee removal? Evidence from Zambia using a pooled synthetic control
Authors: Lépine Aurélia , Lagarde Mylène , Le Nestour Alexis 
Published: October 2017

AbstractDespite its high political interest, the impact of removing user charges for health care in low‐income settings remains a debatable issue. We try to clear up this contentious issue by estimating the short‐term effects of a policy change that occurred in 2006 in Zambia, when 54 of 72 districts removed fees. We use a pooled synthetic control method in order to estimate the causal impact of the policy on health care use, the provider chosen, and out‐of‐pocket medical expenses. We find no evidence that user fee removal increased health care utilisation, even among the poorest group. However, we find that the policy is likely to have led to a substitution away from the private sector for those using care and that it virtually eliminated medical expenditures, thereby providing financial protection to service users. We estimate that the policy was equivalent to a transfer of US$3.2 per health visit for the 50% richest but of only US$1.1 for the 50% poorest.
AHNS Series: Do you know your guidelines? Perioperative antithrombotic management in head and neck surgery
Authors: Meyer Annika , Gross Neil , Teng Marita 
Published: October 2017

AbstractHead and neck surgeons are commonly faced with surgical patients who have underlying medical problems requiring antithrombotic therapy. It is difficult to achieve a balance between minimizing the risk of thromboembolism and hemorrhage in the perioperative period. Data from randomized, controlled trials are limited, and procedure‐specific bleed rates are also difficult to pinpoint. The decision is made more difficult when patients with moderate‐to‐high risk for thromboembolic events undergo procedures that are high risk for bleeding. This is true for many head and neck oncologic surgeries. Furthermore, although elective procedures may be delayed for optimization of antithrombotic medication, emergent procedures cannot. Head and neck surgery often represents the most challenging of all these circumstances, given the potential risk of airway compromise from bleeding after head and neck surgery.
Paternal parenting, child temperament, and problem behaviour: An investigation among young Hong Kong children
Authors: Ren Lixin , Zhang Xiao 
Published: October 2017

AbstractOn the basis of a sample of 109 Chinese children, aged approximately 3 years, and their parents in Hong Kong, this study examined how paternal parenting interacted with 2 aspects of child temperament (i.e., negative emotionality and persistence) to predict children's internalizing and externalizing problems. Paternal supportive and aversive parenting practices were reported by fathers, and child temperament and behavioural problems were reported by both mothers and fathers. The results showed that paternal aversive parenting interacted with temperamental emotionality and persistence in the prediction of children's externalizing problems, controlling for maternal parenting. Specifically, young Chinese children who were more emotionally reactive and those who had lower attentional capacities were more vulnerable to aversive parenting from fathers, exhibiting more externalizing problems. Practical implications are discussed.HighlightsThis study examined the interplay between child temperament and paternal parenting with regard to problem behaviour among Chinese preschoolers.Both mothers and fathers reported child behaviour problems, emotionality, persistence, and their parenting behaviour.Both emotionality and persistence interacted with aversive paternal parenting in relation to child externalizing behaviours, controlling for maternal parenting.