bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Development and Testing of a New Version of the Cognitive Reflection Test Applying Item Response Theory (IRT)
Authors: Primi Caterina , Morsanyi Kinga , Chiesi Francesca , Donati Maria Anna , Hamilton Jayne 
Published: June 2015

AbstractThe cognitive reflection test (CRT) is a short measure of a person's ability to resist intuitive response tendencies and to produce a normatively correct response, which is based on effortful reasoning. Although the CRT is a very popular measure, its psychometric properties have not been extensively investigated. A major limitation of the CRT is the difficulty of the items, which can lead to floor effects in populations other than highly educated adults. The present study aimed at investigating the psychometric properties of the CRT applying item response theory analyses (a two‐parameter logistic model) and at developing a new version of the scale (the CRT‐long), which is appropriate for participants with both lower and higher levels of cognitive reflection. The results demonstrated the good psychometric properties of the original, as well as the new scale. The validity of the new scale was also assessed by measuring correlations with various indicators of intelligence, numeracy, reasoning and decision‐making skills, and thinking dispositions. Moreover, we present evidence for the suitability of the new scale to be used with developmental samples. Finally, by comparing the performance of adolescents and young adults on the CRT and CRT‐long, we report the first investigation into the development of cognitive reflection. Copyright © 2015 John Wiley & Sons, Ltd.
Investigations into the Biosynthesis, Regulation, and Self‐Resistance of Toxoflavin in Pseudomonas protegens Pf‐5
Authors: Philmus Benjamin , Shaffer Brenda T. , Kidarsa Teresa A. , Yan Qing , Raaijmakers Jos M. , Begley Tadhg P. , Loper Joyce E. 
Published: June 2015

AbstractPseudomonas spp. are prolific producers of natural products from many structural classes. Here we show that the soil bacterium Pseudomonas protegens Pf‐5 is capable of producing trace levels of the triazine natural product toxoflavin (1) under microaerobic conditions. We evaluated toxoflavin production by derivatives of Pf‐5 with deletions in specific biosynthesis genes, which led us to propose a revised biosynthetic pathway for toxoflavin that shares the first two steps with riboflavin biosynthesis. We also report that toxM, which is not present in the well‐characterized cluster of Burkholderia glumae, encodes a monooxygenase that degrades toxoflavin. The toxoflavin degradation product of ToxM is identical to that of TflA, the toxoflavin lyase from Paenibacillus polymyxa. Toxoflavin production by P. protegens causes inhibition of several plant‐pathogenic bacteria, and introduction of toxM into the toxoflavin‐sensitive strain Pseudomonas syringae DC3000 results in resistance to toxoflavin.
Structure‐Based Mechanism of Oleate Hydratase from Elizabethkingia meningoseptica
Authors: Engleder Matthias , Pavkov‐Keller Tea , Emmerstorfer Anita , Hromic Altijana , Schrempf Sabine , Steinkellner Georg , Wriessnegger Tamara , Leitner Erich , Strohmeier Gernot A. , Kaluzna Iwona , Mink Daniel , Schürmann Martin , Wallner Silvia , Macheroux Peter , Gruber Karl , Pichler Harald 
Published: June 2015

AbstractHydratases provide access to secondary and tertiary alcohols by regio‐ and/or stereospecifically adding water to carbon‐carbon double bonds. Thereby, hydroxy groups are introduced without the need for costly cofactor recycling, and that makes this approach highly interesting on an industrial scale. Here we present the first crystal structure of a recombinant oleate hydratase originating from Elizabethkingia meningoseptica in the presence of flavin adenine dinucleotide (FAD). A structure‐based mutagenesis study targeting active site residues identified E122 and Y241 as crucial for the activation of a water molecule and for protonation of the double bond, respectively. Moreover, we also observed that two‐electron reduction of FAD results in a sevenfold increase in the substrate hydration rate. We propose the first reaction mechanism for this enzyme class that explains the requirement for the flavin cofactor and the involvement of conserved amino acid residues in this regio‐ and stereoselective hydration.
Synthesis, Characterization, and Repair of a Flexible O6‐2′‐Deoxyguanosine‐alkylene‐O6‐2′‐deoxyguanosine Intrastrand Cross‐Link
Authors: O'Flaherty Derek K. , Wilds Christopher J. 
Published: June 2015

AbstractOligonucleotides tethered by an alkylene linkage between the O6‐atoms of two consecutive 2′‐deoxyguanosines, which lack a phosphodiester linkage between these residues, have been synthesized as a model system of intrastrand cross‐linked (IaCL) DNA. UV thermal denaturation studies of duplexes formed between these butylene‐ and heptylene‐linked oligonucleotides with their complementary DNA sequences revealed about 20 °C reduction in stability relative to the unmodified duplex. Circular dichroism spectra of the model IaCL duplexes displayed a signature characteristic of B‐form DNA, suggesting minimal global perturbations are induced by the lesion. The model IaCL containing duplexes were investigated as substrates of O6‐alkylguanine DNA alkyltransferase (AGT) proteins from human and E. coli (Ada‐C and OGT). Human AGT was found to repair both model IaCL duplexes with greater efficiency towards the heptylene versus butylene analog adding to our knowledge of substrates this protein can repair.
Design, Synthesis, and Characterization of a Photoactivatable Caged Prodrug of Imatinib
Authors: Zindler Melanie , Pinchuk Boris , Renn Christian , Horbert Rebecca , Döbber Alexander , Peifer Christian 
Published: June 2015

AbstractImatinib is the first protein kinase inhibitor approved for clinical use and is a seminal drug for the concept of targeted therapy. Herein we report on the design, synthesis, photokinetic properties, and in vitro enzymatic evaluation of a photoactivatable caged prodrug of imatinib. This approach allows spatial and temporal control over the activation of imatinib triggered by ultraviolet light. The successful application of the photoactivation concept to this significant kinase inhibitor provides further evidence for the caging technique as a feasible approach in the kinase field. The presented photoactivatable imatinib prodrug will be highly useful as a pharmacological tool to study the impact of imatinib toward biological systems in greater detail.
Safety, tolerability, pharmacokinetics, and pharmacodynamic effects of naloxegol at peripheral and central nervous system receptors in healthy male subjects: A single ascending‐dose study
Authors: Eldon Michael A. , Kugler Alan R. , Medve Robert A. , Bui Khanh , Butler Kathleen , Sostek Mark 
Published: June 2015

AbstractThis randomized, double‐blind, placebo‐controlled, ascending‐dose, crossover study evaluated single oral doses of naloxegol (NKTR‐118; 8, 15, 30, 60, 125, 250, 500, and 1000 mg), a PEGylated derivative of naloxone, for safety and tolerability, antagonism of peripheral and central nervous system (CNS) effects of intravenous morphine, and pharmacokinetics. Healthy men were randomized 1:1 to naloxegol or naloxegol‐matching placebo administered with morphine and lactulose in a 2‐period crossover design. Periods were separated by a 5‐ to 7‐day washout. Assessments included safety, tolerability, orocecal transit time (OCTT), pupillary miosis, and pharmacokinetics. The study was completed by 46 subjects. The most common adverse events were somnolence, dizziness, headache, and nausea. Greater reversal of morphine‐induced delay in OCTT occurred with increasing naloxegol dose, demonstrating dose‐ordered antagonism of morphine's peripheral gastrointestinal effects. Forty‐four subjects showed no reversal of pupillary miosis; 2 showed potential partial reversal at 250 and 1000 mg, indicating negligible antagonism of morphine's CNS effects at doses ≤ 125 mg. Rapid absorption, linear pharmacokinetics up to 1000 mg, and low to moderate between‐subject pharmacokinetic variability was observed. The pharmacokinetics of morphine or its glucuronide metabolites were unaltered by concurrent naloxegol administration. Naloxegol was generally safe and well tolerated at single doses up to 1000 mg.
Mesoporous Alumina Nanoparticles as Host Tunnel‐like Pores for Removal and Recovery of Insecticides from Environmental Samples
Authors: Derbalah Aly , El‐Safty Sherif A. , Shenashen Mohamed A. , Abdel Ghany Nabil A. 
Published: June 2015

AbstractWater contamination with lindane, which is a persistent, toxic, and priority insecticide, is a major problem worldwide. This study presents the fabrication of mesoporous alumina nanoparticles (MA–NPs) with a large surface‐area‐to‐volume ratio, active surface sites, and open channel pores to trap/adsorb insecticide molecules, such as lindane. Key factors, such as temperature, pH (i.e., 4.5), adsorbate–adsorbent concentration, and contact time, influence the thermodynamics and kinetics of heterogeneous lindane–MA–NP adsorption. Results show that the maximum adsorption capacity (qm) of lindane is 25.54 mg g−1 at 20 °C. MA–NPs also exhibits a high uptake efficiency (>80 %) of lindane after 20 cycles, which results in effective regeneration and reusability characteristics. MA–NPs were also applied in real environmental samples from tap and lake water sources contaminated with lindane. The results indicate that the MA–NPs show evidence of their environmental impact, their potential influence on the removal and recovery of lindane, and their possible contribution to waste management.
Application of a Bayesian nonparametric model to derive toxicity estimates based on the response of Antarctic microbial communities to fuel‐contaminated soil
Authors: Arbel Julyan , King Catherine K. , Raymond Ben , Winsley Tristrom , Mengersen Kerrie L. 
Published: June 2015

AbstractEcotoxicology is primarily concerned with predicting the effects of toxic substances on the biological components of the ecosystem. In remote, high latitude environments such as Antarctica, where field work is logistically difficult and expensive, and where access to adequate numbers of soil invertebrates is limited and response times of biota are slow, appropriate modeling tools using microbial community responses can be valuable as an alternative to traditional single‐species toxicity tests. In this study, we apply a Bayesian nonparametric model to a soil microbial data set acquired across a hydrocarbon contamination gradient at the site of a fuel spill in Antarctica. We model community change in terms of OTUs (operational taxonomic units) in response to a range of total petroleum hydrocarbon (TPH) concentrations. The Shannon diversity of the microbial community, clustering of OTUs into groups with similar behavior with respect to TPH, and effective concentration values at level x, which represent the TPH concentration that causes x% change in the community, are presented. This model is broadly applicable to other complex data sets with similar data structure and inferential requirements on the response of communities to environmental parameters and stressors.
Posture Control for Personal Mobility Robot Using Feedback Compensation with Unstable Pole
Authors: Hirose Noriaki , Tajima Ryosuke , Sukigara Kazutoshi , Tsusaka Yuji 
Published: June 2015

SUMMARYThis paper presents a novel posture control approach using feedback compensation with an unstable pole. For a narrow and small personal mobility robot (PMR), this is needed in order to control its posture for achieving quick turning and high acceleration. However, in the conventional control approach that uses the posture angle as a controlled variable, the zero moment point (ZMP) does not settle to the desired point in the following cases: an unknown disturbance force given to the PMR, a fluctuation in the center of gravity of the PMR, and a change in the conditions between the tires and the road surface. In this paper, a novel control method using feedback compensation with an unstable pole is proposed to achieve the desired ZMP in the steady state. The proposed controller changes the control input for the actuator of posture control to zero in order to achieve the desired posture angle. The effectiveness of the proposed approach is verified through experiments using a prototype of the PMR.
Central habituation and distraction alter C‐fibre‐mediated laser‐evoked potential amplitudes
Authors: Hüllemann P. , Shao Y.Q. , Manthey G. , Binder A. , Baron R. 
Published: June 2015

AbstractBackgroundRecent studies applied laser‐evoked potentials (LEP) for the analysis of small nerve fibre function and focused on the detection of stable C‐fibre‐mediated potentials (C‐LEPs); high technical requirements were needed. The diagnostic significance is still controversially discussed. So far, only few studies focused on the susceptibility of C‐LEPs to distraction and other influences. We hypothesized that C‐LEPs are altered by habituation processes and distraction.MethodsTwelve subjects were tested with a C‐fibre laser set‐up (neodymium:yttrium‐aluminium‐perovskite laser with a 10‐mm beam diameter and 10‐ms stimulus time) at the left perioral area. In condition I, the subjects received repetitive painful laser stimuli at the right hand to induce habituation. In condition II, the subjects had to fulfil an auditory discrimination task (where the subjects had to estimate the pitch of different tones on a scale for 20 min). C‐LEPs were retrieved before and after the habituation or distraction paradigm. C‐LEPs were also measured in a control group who was not influenced by laser stimuli or other disturbances during a 23‐min break between the two test sessions.ResultsIn both test conditions, there was significant C‐LEP amplitude reduction. The LEP amplitudes of the control group remained unchanged.ConclusionsIn the approach of detecting C‐fibre‐mediated potentials with LEP, future studies should take the high susceptibility to distraction and habituation into account.
Effects of an antidepressant mixture on the brain serotonin and predation behavior of hybrid striped bass
Authors: Bisesi Joseph H. , Sweet Lauren E. , van den Hurk Peter , Klaine Stephen J. 
Published: June 2015

Abstract

Antidepressants have been found in measurable concentrations in final treated wastewater effluent and receiving waters throughout the world. Studies have shown that these concentrations are typically not overtly toxic, but the psychotropic mode of action of these chemicals warrants examination of their behavioral effects. Exposure of hybrid striped bass to the antidepressants fluoxetine or venlafaxine alone has been shown to cause decreased brain serotonin levels and increased time to capture prey at concentrations typically 1 to 2 orders of magnitude higher than environmentally relevant concentrations. In the present study, equally effective doses of fluoxetine and venlafaxine were used to perform a mixture study, using a toxic unit approach to determine whether these antidepressants may act in an additive manner at lower concentrations. The results indicated that mixtures of these antidepressants caused decreased brain serotonin and increased time to capture prey at concentrations lower than reported in previous studies. Low concentration mixtures caused an additive effect on brain serotonin levels and time to capture prey, whereas higher concentrations were less than additive. The results were consistent with the dose addition concept, with higher concentration mixtures potentially saturating the effects on serotonin in the brain. Results from the present study indicate that antidepressants have the potential to be additive on the biochemical and individual scale, which necessitates more robust analysis of antidepressant mixtures and their potential to act together in low concentration scenarios. Environ Toxicol Chem 2016;35:938–945. © 2015 SETAC
Sediment concentrations in run‐off varying with spatial scale in an agricultural subwatershed of the Chinese Loess Plateau
Authors: Zheng Mingguo , Li Runkui , He Jijun 
Published: June 2015

AbstractInformation is scarce on the spatial‐scale effect on sediment concentrations in run‐off. This study addressed this issue within an agricultural subwatershed of the Chinese Loess Plateau, using data observed at a hilltop plot, three nested hillslope plots, two entire‐slope plots (a combination of hillslope and valley side slope) and the subwatershed outlet. Dominated by the splash and sheet erosions, the hilltop plot has a minimum Cae (mean sediment concentration for all recorded events) of 45 kg m−3. Unexpectedly, the high sediment concentrations at the hilltop do not occur at high rainfall intensities or large run‐off events because of the protection of surface soils by relatively thick sheet flows. Because of the emergence of rills, Cae is as high as 310 kg m−3 even on the most upper hillslope. Downslope, both Cae and ESC (extreme large values of recorded sediment concentrations) increase; such a slope length effect attenuates with increasing slope length and event magnitude as a result of insufficient sediment availability associated with rill development. Active mass wastings ensure sufficient sediment supply and thus a spatially invariant Cae (approximately 700 kg m−3) and ESC (approximately 1000 kg m−3) at the scale of the entire slope and subwatershed. Detailed examination shows that most small events experience a decrease in sediment concentrations when moving from the entire slope to the subwatershed, indicating that the spatially invariant sediment concentration is valid only for large run‐off events. This study highlights the control of the spatial scale, which determines the dominant erosional process, on erosional regime. Copyright © 2015 John Wiley & Sons, Ltd.
Impact of aqueous two‐phase system design parameters upon the in situ refolding and recovery of invertase
Authors: Sánchez‐Trasviña Calef , González‐Valdez José , Mayolo‐Deloisa Karla , Rito‐Palomares Marco 
Published: June 2015

ABSTRACTBACKGROUNDProtein refolding represents the limiting step in the recovery of these molecules from inclusion bodies and from denaturing operations. This raises the need for establishing different methodologies to efficiently recover and refold proteins. Aqueous two‐phase systems (ATPS) besides being a primary recovery operation provide good and affordable physicochemical conditions to refold these molecules.RESULTS48 different PEG–potassium phosphate ATPS were tested for the partition and refolding of native and denatured invertase. Invertase in both forms has a partition preference for the bottom salt‐rich phase where the polymer molecular weight and the tie‐line length (TLL) selected for the system play a preponderant role. Refolding percentages of up to 100% can be obtained in the polymer‐rich phase and between 50% and 75% in the bottom phase.CONCLUSIONSThis study reports the characterization of how the different ATPS design parameters such as polymer molecular weight, tie‐line length (TLL) and volume ratio (VR), influence protein partition and refolding using invertase as the protein model. A PEG 3350 g mol−1, TLL 25.0% w/w and VR = 1.00 system was selected as the best option for denatured invertase recovery and refolding with an enzyme recovery of 60.8% and a refolding percentage of 59.7% in the bottom phase of the system. These findings represent advancements en route to establishing an ATPS operation for the potential in situ recovery and refolding of denatured protein based‐products. © 2015 Society of Chemical Industry
Magnetic susceptibility contrast variations in multiple sclerosis lesions
Authors: Li Xu , Harrison Daniel M. , Liu Hongjun , Jones Craig K. , Oh Jiwon , Calabresi Peter A. , van Zijl Peter C.M. 
Published: June 2015

PurposeRecent magnetic resonance imaging (MRI) studies have revealed heterogeneous magnetic susceptibility contrasts in multiple sclerosis (MS) lesions. Due to its sensitivity to disease‐related iron and myelin changes, magnetic susceptibility‐based measures may better reflect some pathological features of MS lesions. Hence, we sought to characterize MS lesions using combined R2* mapping and quantitative susceptibility mapping (QSM).Materials and MethodsIn all, 306 MS lesions were selected from 24 MS patients who underwent 7T MRI. Maps of R2*, frequency, and quantitative susceptibility were calculated using acquired multiecho gradient echo (GRE) phase data. Lesions were categorized based on their image intensity or their anatomical locations. R2* and susceptibility values were quantified in each lesion based on manually drawn lesion masks and compared between lesion groups showing different contrast patterns. Correlations between R2* and susceptibility were also tested in these lesion groups.ResultsIn 38% of selected lesions the frequency map did not show the same contrast pattern as the susceptibility map. While most lesions (93%) showed hypointensity on R2*, the susceptibility contrast in lesions varied, with 40% being isointense and 58% being hyperintense in the lesion core. Significant correlations (r = 0.31, P < 0.001) between R2* and susceptibility were found in susceptibility hyperintense lesions, but not in susceptibility isointense lesions. In addition, a higher proportion (74%) of periventricular lesions was found to be susceptibility hyperintense as compared to subcortical (53%) or juxtacortical (38%) lesions.ConclusionCombining R2* and QSM is useful to characterize heterogeneity in MS lesions. J. Magn. Reson. Imaging 2016;43:463–473.
Anomalies of Northern Hemisphere ozone associated with a tropopause‐lower stratosphere teleconnection during summer
Authors: Wang Yuanxiang , Zhao Ping , Xu Haiming , Liu Ge 
Published: June 2015

ABSTRACTUsing the ozone data set from the satellite observations and the atmospheric reanalysis data sets during 1979–2005, we examine the variability of a tropopause‐lower stratosphere (TS) teleconnection a and its relationship with the ozone change over the Northern Hemisphere (NH) during summer. The TS teleconnection has an approximate opposite phase to that in the upper‐troposphere Asian‐Pacific Oscillation (APO), and the TS teleconnection index (the TS index) is also related well to the APO index. Corresponding to a higher TS index, the ozone generally decreases in the NH mid‐high latitudes (near 40°N and the Far East of Russia). This link between the TS teleconnection and the ozone is physically supported by the changes of the background atmospheric circulation. When the TS index is higher, the decrease of the ozone is closely associated with an increase of the local tropopause height. The upward and downward motion variations in the upper troposphere and the lower stratosphere in the east and west parts of the anomalous anticyclones associated with the TS index strengthen the exchanges of the ozone between the troposphere and the lower stratosphere, which may cause a decrease of the ozone. The horizontal advection of the ozone could also contribute to the ozone decreases over these regions.