bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modern Aspects of the Smiles Rearrangement
Authors: Holden Catherine M. , Greaney Michael F. 
Published: April 2017

AbstractThe Smiles rearrangement is an intramolecular SNAr reaction, breaking a C−X single bond and forming a new C−X or C−C bond though ipso substitution. Its vast scope, in terms of nucleophile, leaving group, and ring‐size of the transition state, make it a powerful tool for arene functionalization, as it can be employed strategically to switch easily‐forged bonds with more difficult connections that would be challenging to realize in the intermolecular mode. The reaction has received significantly renewed attention in recent years, as advances in areas such as arene C−X bond formation and radical generation have been harnessed for new arene syntheses through Smiles chemistry. In addition, new reaction modes have been discovered, such as the Clayden rearrangement of lithiated ureas, creating innovative applications for Smiles rearrangements in asymmetric arylation. This Minireview will discuss advances in these areas in the recent literature, covering both two‐electron, polar Smiles rearrangements along with single‐electron radical transformations.
Highly enantioselective asymmetric direct aldol reaction promoted by aziridine amides constructed on chiral terpene scaffold
Authors: Wujkowska Zuzanna , Strojewska Aleksandra , Pieczonka Adam M. , Leśniak Stanisław , Rachwalski Michał 
Published: April 2017

AbstractOptically pure, diastereomeric aziridine amides built on the chiral skeletons of camphor, fenchone, and menthone have proven to be highly efficient ligands for enantioselective asymmetric direct aldol reaction in the presence of water and zinc triflate. Desired products were formed in moderate to high chemical yields (up to 95%) and with enantiomeric excess up to 99%. The influence of the stereogenic centers located at the aziridine subunit on the stereochemical course of the reaction is discussed.
Association of salivary RANKL and osteoprotegerin levels with periodontal health
Authors: Ochanji A. A. , Matu N. K. , Mulli T. K. 
Published: April 2017

AbstractThe aim of this study is to determine the association of salivary levels of the bone remodelling regulators (RANKL) and osteoprotegerin (OPG) with periodontal clinical status. One‐hundred fifty‐eight participants selected from a pool of adult patients via systematic random sampling were included in this descriptive cross‐sectional study carried out at the University of Nairobi Dental Hospital. About 5 ml of unstimulated whole saliva was collected from each participant followed by periodontal clinical examination. Salivary levels of RANKL and OPG were determined using human RANKL and OPG ELISA kits from R&D systems, UK. The mean salivary level of RANKL was 14.65pg/ml (+18.72 SD) with strong association to periodontal disease severity (F = 64.82, p < .001). Mean OPG levels was 139.03 pg/ml (+51.19 SD) with significantly high levels in cases without periodontitis (F = 19.031, p < .001). Consequently, a relative RANKL/OPG ratio was established with a strong positive correlation to disease severity (rs = .759, p < .001). Statistically significant area under curve value of .932 was reported (.1613 cutoff ratio, 95% sensitivity, 6.2% specificity). The levels of RANKL and OPG in saliva and their relative ratio have strong association with the severity of periodontal disease, hence a potential adjunctive diagnostic in evaluating periodontal disease.
Unexpected population response to increasing temperature in the context of a strong species interaction
Authors: White Jeffrey D. , Sarnelle Orlando , Hamilton Stephen K. 
Published: April 2017

AbstractClimate change is driving large changes in the spatial and temporal distributions of species, with significant consequences for individual populations. Community‐ and ecosystem‐level implications of altered species distributions may be complex and challenging to anticipate due to the cascading effects of disrupted interactions among species, which may exhibit threshold responses to extreme climatic events. Toxic, bloom‐forming cyanobacteria like Microcystis are expected to increase worldwide with climate change, due in part to their high temperature optima for growth. In addition, invasive zebra mussels (Dreissena polymorpha) have caused an increase in Microcystis aeruginosa, a species typically associated with eutrophication, in low‐nutrient lakes. We conducted a 13‐yr study of a M. aeruginosa population in a low‐nutrient lake invaded by zebra mussels. In 10 of the 13 years, there was a significant positive relationship between M. aeruginosa biomass and accumulated degree days, which are projected to increase with climate change. In contrast, Microcystis biomass was up to an order of magnitude lower than predicted by the above relationship during the other three years, including the warmest in the data set, following repeated heat‐induced mass mortality of D. polymorpha. Thus, the positive relationship between Microcystis biomass and temperature was negated when its facilitating species was suppressed during a series of exceptionally warm summers. Predicting the net response of a species to climate change may therefore require, at minimum, quantification of responses of both the focal species and species that strongly interact with it over sufficiently long time periods to encompass the full range of climatic variability. Our results could not have been predicted from existing data on the short‐term responses of these two interacting species to increased temperature.
The consistency of a species’ response to press perturbations with high food web uncertainty
Authors: Tunney Tyler D. , Carpenter Stephen R. , Vander Zanden M. Jake 
Published: April 2017

AbstractPredicting species responses to perturbations is a fundamental challenge in ecology. Decision makers must often identify management perturbations that are the most likely to deliver a desirable management outcome despite incomplete information on the pattern and strength of food web links. Motivated by a current fishery decline in inland lakes of the Midwestern United States, we evaluate consistency of the responses of a target species (walleye [Sander vitreus]) to press perturbations. We represented food web uncertainty with 193 plausible topological models and applied four perturbations to each one. Frequently the direction of the focal predator response to the same perturbation is not consistent across food web topologies. Simultaneous application of management perturbations led to less consistent outcomes compared to the best single perturbation. However, direct manipulation of the adult focal predator produced a desirable outcome in 77% of 193 plausible topologies. Identifying perturbations that produce consistent outcomes in the face of food web uncertainty can have important implications for natural resource conservation and management efforts.
Tailoring mineralocorticoid receptor antagonist therapy in heart failure patients: are we moving towards a personalized approach?
Authors: Ferreira João Pedro , Mentz Robert J. , Pizard Anne , Pitt Bertram , Zannad Faiez 
Published: April 2017

AbstractThe aim of personalized medicine is to offer a tailored approach to each patient in order to provide the most effective therapy, while reducing risks and side effects. The use of mineralocorticoid receptor antagonists (MRAs) has demonstrated major benefits in heart failure with reduced ejection fraction (HFrEF), results with challenging inconsistencies in heart failure with preserved ejection fraction (HFpEF), and ‘neutral’ preliminary results in acute heart failure. Data derived from landmark trials are generally applied in a ‘one size fits all’ manner and the development and implementation of more personalized MRA management would offer the potential to improve outcomes and reduce side effects. However, the personalization of pharmacotherapy regimens remains poorly defined in the cardiovascular field (in light of current knowledge) and until further trials targeting specific subpopulations have been conducted, MRAs should be provided to the great majority of HFrEF patients in the absence of contraindication. Spironolactone should be considered for symptomatic HFpEF patients with elevated natriuretic peptides. In the near future, trials should target HFrEF patients using exclusion criteria sourced from landmark trials (e.g. severe renal impairment), select more homogeneous HFpEF populations (e.g. with elevated BNP and structural abnormalities on echocardiography), and determine which patients are likely to benefit from MRAs (e.g. according to prespecified biomarkers).
Electrochemical Study of 2,4‐Dinitrophenylhydrazine as Derivatization Reagent and Aldehydes at Carbon Glassy Electrode
Authors: Boumya W. , Hammani H. , Laghrib F. , Lahrich S. , Farahi A. , Achak M. , Bakasse M. , Mhammedi M. A. El 
Published: April 2017

AbstractA selective method based on derivatization with 2,4‐dinitrophenylhydrazine (DNPH) is described for the determination of several carbonyl compounds. The factors affecting the derivatization reaction of aldehyde and DNPH were investigated. The product of the derivatization reaction has been characterized by UV/Vis spectrophotometry, NMR, infrared spectroscopy and cyclic voltammetry. Then, an electrochemical study for the determination of aldehyde‐2.4‐dinitrophenylhydrazone was performed at glassy carbon electrode (GCE) using square wave voltammetry (SWV). After the optimization of experimental parameters, the limits of detection (at 3σ) obtained for all aldehyde‐2,4‐DNPH were varied from 15.82 to 78.39 μmol L−1 and relative standard deviations were between 1.8 and 4.5%. Finally, the proposed method was applied to determine the aldehydes concentration in drinking water and orange juice samples with satisfactory results.
Pseudoreplication and the usage of biomarkers in ecotoxicological bioassays
Authors: Tincani Flávio H. , Galvan Gabrieli L. , Marques Antonio E.M.L. , Santos Gustavo S. , Pereira Letícia S. , da Silva Thiago A. , Silva de Assis Helena C. , Barbosa Ronilson V. , Cestari Marta M. 
Published: April 2017

Abstract

Pseudoreplication is a widely discussed topic in the scientific community. Its principal critique concerns the lack of independence in flawed experimental designs and the use of inferential statistics to test the hypothesis of such experiments. Thirty years after its appearance, it remains misunderstood by many researchers, including ecotoxicologists. In the present study, we try to clarify some of its concepts by filling in what seems to be a gap in the terminology of manipulative experiments. We propose the term “experimental medium” to refer strictly to the relevant spatial scale of the experiment to preserve the specificity of the experimental and observational units and to display pseudoreplication as a kind of misinterpretation and/or misanalysis of inferential statistics. A classification of the types of experimental designs in ecotoxicology is offered, and the problems in using inferential statistics in suboptimal designs are discussed. We hope to shed some light on such a classic topic for ecotoxicologists. Environ Toxicol Chem 2017;36:2868–2874. © 2017 SETAC
Sediment toxicity identification evaluation (TIE phases I and II) based on microscale bioassays for diagnosing causes of toxicity in coastal areas affected by domestic sewage
Authors: Ferraz Mariana Aliceda , Alves Aline Vecchio , de Cássia Muniz Cynthia , Pusceddu Fabio Hermes , Gusso-Choueri Paloma Kachel , Santos Aldo Ramos , Choueri Rodrigo Brasil 
Published: April 2017

Abstract

Domestic sewage is a major problem in highly urbanized coastal areas worldwide. In the present study, toxicity identification evaluation (TIE) phases I and II were applied to sediment interstitial water from 2 locations along the São Paulo coast in southeastern Brazil: the sewage outfalls from the city of Santos, a densely urbanized area, and the city of Bertioga, a less urbanized area. An adapted microscale sea urchin embryo–larval development bioassay was employed. Phase TIE-I manipulations were 1) ethylenediamine tetraacetic acid (EDTA) addition, 2) aeration at modified pH, 3) C18 solid-phase extraction (SPE), and 4) addition of Na2S2O3. The results of the Santos TIE-I indicated toxicity by sulfides and substances with affinity to C18 resin. In Bertioga, toxicity was the result of NH3, metals, and arsenic, as well as substances with affinity to C18 resin. Phase TIE-II aimed to specify the causes of toxicity by testing the toxicity of eluates of the sublation and C18 SPE manipulation. The results reinforced the role of both surfactants and nonpolar compounds as causative agents of toxicity in both Santos and Bertioga. Chemical analyses of sediment interstitial water or whole sediment ruled out the influence of polycyclic aromatic hydrocarbons (PAHs) or polychlorinated biphenyls (PCBs) in the toxicity of both sampling sites. Other hydrophobic substances may play a role in the toxicity of Santos and Bertioga effluents. Efforts to remove such substances from sanitary effluents must be prioritized. Environ Toxicol Chem 2017;36:1820–1832. © 2017 SETAC
Performance of dual‐hop DF relaying systems with QAM schemes over mixedη‐μandκ‐μfading channels
Authors: Dixit Dharmendra , Sahu P. R. 
Published: April 2017

AbstractPerformance of a dual‐hop decode‐and‐forward relaying system that uses quadrature amplitude modulation (QAM) scheme is analyzed over mixedη‐μandκ‐μfading channels. Closed‐form expressions are derived for the average symbol error rate (ASER) for rectangular QAM and cross QAM schemes using moment‐generating function‐based approach. The obtained ASER expressions accommodate other mixed fading channels addressed in the literature, as special cases. Further, a simple expression for the asymptotic ASER has been obtained, useful to determine the system performance at high signal‐to‐noise‐ratio values. The obtained asymptotic ASER results reveal that the diversity order is determined by the most severely faded link while the coding gain is affected by the total power of the system. Additionally, we analyze the optimal power allocation method, which provides a practical design rule to optimally distribute the total transmission power between the source and the relay to minimize the ASER. Extensive numerical and computer simulation results are presented that confirm the accuracy of presented mathematical analysis.
SO2 removal characteristics using waste CaO from calcium looping CO2 capture process
Authors: Shao Yan , He Donglin , Qin Changlei , Ran Jingyu , Zhang Li 
Published: April 2017

AbstractCalcium looping (CaL) has been identified to be a valuable candidate for CO2 capture and has entered a stage of large‐scale experiment and application. However, the serious loss‐in‐capacity problem will result in the production of a large amount of waste CaO, which not only increases the economic cost of the capture process, also generates a huge risk of secondary pollution. In this work, the waste CaO from CaL was first proposed to be used for SO2 removal by wet desulfurization and the SO2 sorption characteristics were comprehensively studied. Through experimental test and analysis, it is found that CaL‐spent CaO derived from dolomite can achieve higher efficiency than that from the limestone in SO2 removal. The effect of CaL cycle on the SO2 removal performance is observed to be small when the cycle number is under 40. Beyond that, the SO2 removal capacity decreases quickly, which is thought to be due to the variation in slaking rate determined by the compromise between the surface area and pore size distribution of the material. Furthermore, sulfation performance of waste CaO is found to be superior with a particle size smaller than 0.4 mm. This work proves the feasibility of the utilization of CaL‐spent CaO in wet SO2 removal, and could be beneficial for understanding the SO2 sorption characteristics of CaL‐spent materials. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.
Valuation of Life as outcome and mediator of a depression intervention for older African Americans: the Get Busy Get Better Trial
Authors: Gitlin Laura N. , Parisi Jeanine M. , Huang Jin , Winter Laraine , Roth David L. 
Published: April 2017

ObjectivePreviously, we showed that Get Busy Get Better (GBGB), a 10‐session multicomponent home‐based, behavioral intervention, reduced depressive symptom severity in older African Americans. As appraising the value of life is associated with depressive symptoms, this study examined whether GBGB enhanced positive appraisals of life and if, in turn, this mediated treatment effects on depressive symptoms.MethodsData were from a single‐blind parallel randomized trial involving 208 African Americans (≥55 years old) with depressive symptoms (Patient Health Questionnaire, PHQ‐9 ≥5). GBGB involved five components: care management, referral/linkage, stress reduction, depression education, and behavioral activation. A 13‐item Valuation of Life (VOL) scale with two subfactors (optimism and engagement) was examined as an outcome and as mediating GBGB effects on PHQ‐9 scores at 4 months.ResultsOf 208 enrolled African Americans, 180 completed the 4‐month interview (87 = GBGB; 93 = control). At 4 months, compared with wait‐list control group participants, the GBGB group had improved VOL (difference in mean changes from baseline = 4.67, 95% confidence interval 2.53, 6.80). Structural equation models indicated that enhanced VOL mediated a significant proportion of GBGB's impact on depressive symptoms, explaining 71% of its total effect, and its subfactors (optimism, explaining 67%; engagement, 52%).ConclusionValuation of Life appears malleable through an intervention providing resources and activation skills. GBGB's impact on depressive symptoms is attributed in large part to participants' enhanced attachment to life. Attention to VOL as mediator and outcome and the reciprocal relationship between mood and attachment to life is warranted. Copyright © 2017 John Wiley & Sons, Ltd.
Digital Participation, Agency, and Choice: An African American Youth's Digital Storytelling About Minecraft
Authors: Lewis Ellison Tisha 
Published: April 2017

AbstractThis case study examines one African American adolescent male's digital choices and experiences during the creation of a digital story about Minecraft. This study introduces digital participatory choice cultures as a framework to consider how he might recognize and use existing meaning‐making and composition strategies to bridge what young people know, do, and learn both within and outside educational settings. Data include interviews, observations, photo elicitation, digital photos, and digital and nondigital texts. First, the author highlights the student's choices to create a topic and digital story. Second, the author examines how the student's digital choices illustrate the literacies, agency, and identities inherent in digital participatory choice culture, which helped him express himself in both cultural and digital ways. The analysis demonstrates how race mattered in the student's digital composition, which suggests that literacy educators can design instruction to learn about and build from their students’ already existing funds of knowledge.
Regionalization of climate over the Argentine Pampas
Authors: Aliaga Vanina S. , Ferrelli Federico , Piccolo María Cintia 
Published: April 2017

ABSTRACTThe aim of this study was to classify and characterize the climate of the Pampas, a vast region in the centre of Argentina. Due to its territorial extension, a climatic zoning of the region was performed, based on the topography and the most relevant climatological parameters. Climate data from 33 stations of the National Meteorological Service were analysed considering the period 1960–2010. A cluster analysis from the hierarchical method of Ward with an interval squared Euclidean distance as a measure of dissimilarity was applied. The obtained clusters responded to the north–south temperature gradient of the Pampas, influenced by geographical features such as the Tandilia and Ventania hills in Buenos Aires Province and the Pampean hills in Córdoba. Precipitation had a northeast–southwest gradient, and the influence of the arid southwest diagonal of the Pampas was appreciated by determining a semi‐arid environment. The proximity to the sea marked the average humidity values, whereas the winds of strong intensity were registered in the south and west of the region. On the other hand, the standard precipitation index was calculated to identify wet and dry cycles in each cluster. It allowed to characterize these events considering frequency, periodicity, duration and intensity, resulting in the definition of eight climatic subregions.
Hard Outside and Soft Inside
Authors: Schumann Detlef , Leipe Peter 
Published: April 2017

AbstractAs to complex component geometries and components subject to wear — for which conventional hardening techniques often fail —, the laser‐beam hardening process nowadays offers new solutions to create wear‐resistant surfaces. In particular, curved and surfaces that are difficult to access, holes as well as components that easily warp can be efficiently hardened by means of laser. The challenges and solutions for series production are exemplified here by a component used in diesel injection technology.
The use of oculomotor, vestibular, and reaction time tests to assess mild traumatic brain injury (mTBI) over time
Authors: Hoffer Michael E. , Balaban Carey , Szczupak Mikhaylo , Buskirk James , Snapp Hillary , Crawford James , Wise Sean , Murphy Sara , Marshall Kathryn , Pelusso Constanza , Knowles Sean , Kiderman Alex 
Published: April 2017

ObjectivesThe objective of this work is to examine the outcomes of a set of objective measures for evaluating individuals with minor traumatic brain injury (mTBI) over the sub‐acute time period. These methods involve tests of oculomotor, vestibular, and reaction time functions. This work expands upon published work examining these test results at the time of presentation.Study DesignThis study is a prospective age‐ and sex‐matched controlled study.Materials and MethodsThe subject group was composed of 106 individuals with mTBI and 300 age‐ and sex‐matched controls without a history of mTBI. All individuals agreeing to participate in the study underwent a battery of oculomotor, vestibular, and reaction time tests (OVRT). Those subjects with mTBI underwent these tests at presentation (within 6 days of injury) and 1 and 2weeks post injury. These outcomes were compared to each other over time as well as to results from the controls that underwent 1 test session.ResultsSix measures from 5 tests can classify the control and mTBI during Session 1 with a true positive rate (sensitivity) of 84.9% and true negative rate (specificity) of 97.0%. Patterns of abnormalities changed over time in the mTBI group and overall normalized in a subset of individuals at the third (final) testing session.ConclusionsWe describe an objective and effective second generation testing algorithm for diagnosing and following the prognosis of mTBI/concussion. This testing paradigm will allow investigators to institute better treatments and provide more accurate return to activity advice.Level of Evidence3