bluuebunny/crossref_metadata_2025 huggingface dataset:
Strain field evolution at the ductile-to-brittle transition: a case study on ice
Authors: Chauve Thomas , Montagnat Maurine , Lachaud Cedric , Georges David , Vacher Pierre
Published: September 2017

Abstract. This paper presents, for the first time, the evolution of the local heterogeneous strain field around intra-granular cracking in polycrystalline ice, at the onset of tertiary creep. Owing to the high homologous temperature conditions and relatively low compressive stress applied, stress concentration at the crack tips is relaxed by plastic mechanisms associated with dynamic recrystallization. Strain field evolution followed by digital image correlation (DIC) directly shows the redistribution of strain during crack opening, but also the redistribution driven by crack tip plasticity mechanisms and recrystallization. Associated local changes in microstructure induce modifications of the local stress field evidenced by crack closure during deformation. At the ductile-to-brittle transition in ice, micro-cracking and dynamic recrystallization mechanisms can co-exist and interact, the later being efficient to relax stress concentration at the crack tips.
Regional modeling of the Shirase drainage basin, East Antarctica: full Stokes vs. shallow ice dynamics
Authors: Seddik Hakime , Greve Ralf , Zwinger Thomas , Sugiyama Shin
Published: September 2017

Abstract. A hierarchy of approximations of the force balance for the flow of grounded ice exists, ranging from the most sophisticated full Stokes (FS) formulation to the most simplified shallow ice approximation (SIA). Both are implemented in the ice flow model Elmer/Ice, and we compare them by applying the model to the East Antarctic Shirase drainage basin. First, we apply the control inverse method to infer the distribution of basal friction with FS. We then compare FS and SIA by simulating the flow of the drainage basin under present-day conditions and for three scenarios 100 years into the future defined by the SeaRISE (Sea-level Response to Ice Sheet Evolution) project. FS reproduces the observed flow pattern of the drainage basin well, in particular the zone of fast flow near the grounding line, while SIA generally overpredicts the surface velocities. As for the transient scenarios, the ice volume change (relative to the constant-climate control run) of the surface climate experiment is nearly the same for FS and SIA, while for the basal sliding experiment (halved basal friction), the ice volume change is  ∼  30 % larger for SIA than for FS. This confirms findings of earlier studies that, in order to model ice sheet areas containing ice streams and outlet glaciers with high resolution and precision, careful consideration must be given to the choice of a suitable force balance.
Aristóteles y el problema de la metafísica
Authors: Aubenque Pierre
Published: September 2017

En este trabajo, presentado por primera vez en 1959 en forma de conferencia, el autor expone las líneas fundamentales del argumento que, poco después, desarrollará extensamente en El problema del ser en Aristóteles (1962). Ya aquí encontramos afirmado que la investigación de Aristóteles conocida con el título de Metafísica se escinde en dos cuestiones igualmente originarias y que nunca llegan a converger, a saber, la cuestión del comienzo y la cuestión de la unidad. La permanente simultaneidad de ambas preguntas constituye lo que es preciso reconocer como problemática aristotélica, y ello frente a la pretensión de los comentaristas sistematizantes, pero también de quienes intentan resolver la aludida escisión apelando a una supuesta evolución del pensamiento de Aristóteles.
Una formulación actualizada de las vías tomistas para demostrar la existencia de Dios: el argumento ontológico y las tres primeras vías”.
Authors: A. Casanova Carlos
Published: September 2017

Este artículo trata sobre las relaciones entre el conocimiento de Dios y la experiencia sensorial y sobre las tres primeras vías tomistas para demostrar la existencia de Dios. Complementa las vías con los aportes y críticas de las perspectivas fenomenológico-realista y analítica. Para lograr esto de manera sintética, selecciona un autor central de cada una de estas tradiciones: Josef Seifert y Richard Swinburne.
“Piedad y prosperidad. Una lectura de la Elegía a las musas de Solón”.
Authors: Díaz López Lucas
Published: September 2017

El presente artículo expone una lectura de la Elegía a las musas de Solón que defiende su carácter unitario a partir de su forma de plegaria. El ruego del inicio del poema origina las consideraciones siguientes, a la vez que estas muestran por qué es necesaria la forma piadosa del poema. De esta forma, la Elegía apunta a una inseparabilidad entre lo que allí se denomina ólbos y la dimensión de la piedad, que posteriormente se verá confirmada en la obra legislativa soloniana.
Del mito al logos moderno: Giovanni Pico della Mirandola o el hombre en busca de imagen
Authors: Esmorís Galán Lorena
Published: September 2017

Este artículo aborda la construcción de una imagen ejemplar del individuo moderno en el siglo xv. El corpus textual se concentra en una obra fundamental en la historia del pensamiento occidental: el Discurso sobre la dignidad del hombre de Giovanni Pico della Mirandola, que representa el «espíritu de una época» y proyecta una imagen ejemplar del ser humano a través de la reescritura del mito del origen del hombre. Así, se analiza la creación de Adán y qué define la nueva hechura adánica, que servirá de fundamento a una forma de ser, liberada de la doctrina del pecado original y de su merma de las capacidades del ser humano. A través de esta reconstrucción mitológica, así como de las modificaciones que se introducen en el relato bíblico, se van decantando algunos de los rasgos más destacables del hombre que está por venir. Entre ellos, se prestará especial atención al desplazamiento que sufre el hombre, en su hiato con el mundo, al erigirlo en contemplador del universo, a las consecuencias de la liberación adánica de la scala naturae y al protagonismo del deseo en la concepción piquiana del hombre.
La impronta escotista en la metafísica de Suárez: conocimiento intuitivo, actualidad de la materia prima e hipostatización del accidente
Authors: Prieto López Leopoldo José
Published: September 2017

La impronta escotista en la metafísica de Suárez se advierte, además de en la teoría de un conocimiento intelectual directo de lo material, en la idea de que la materia prima no es pura potencia, sino que posee un acto propio, así como en la tesis de que el accidente posee igualmente un ser propio. De estas dos ideas, además de la tendencia a la hipostatización o sustancialización tanto de la materia como del accidente, resulta la ruptura de la unidad de la sustancia material, tanto en el plano sustancial como en el accidental, que Suárez, al igual que Escoto, trata de remediar apelando a los modos de unión. Finalmente, una consecuencia fundamental de la hipostatización del accidente es el fenomenismo, tal como se observa en autores como Locke y Kant.
Nietzsche al futuro
Authors: Rodríguez González Mariano
Published: September 2017

Vogel, Beatrix (Hg.), Umwertung der Menschenwürde–Kontroversen mit und nach Nietzsche. Mit einem Vorwort von Michael von Brück. Freiburg / München, Karl Alber, 2014 (2ª), 426 págs.
Textual Organization for Effective and Meaningful Communication: A Focus on the Speeches of Muhammadu Buhari
Authors: Destiny Idegbekwe
Published: September 2017

Texts are not just texts. Texts are considered texts because of the structure and organization they have. Many linguists do not pay attention to the structure of the text instead attention is paid to the nature of delivery and other aspects of the text. Thereby leaving a vacuum as to what is the internal build of a text. In response to this, the present study presents an analysis of the textual patterns of four of Buhari’s speeches focusing on the textual patterning models of problem to solution, General to Specific and Claim to Counter Claim. The purpose of the study is to unravel the technique behind the arrangement of ideas in the speeches. The study adopts Hoey’s theory of textual patterning as the theoretical framework and reveals amongst others that in the problem to solution model, more problems are presented in Speech A and C which were presented in Nigeria against Speech B and D presented in the United States and in Ethiopia respectively. The problems presented in Speech A and C are local and remote problems related to Nigerians alone while the problems presented in Speech B and D have global links as they affect many countries. The study also discovers that the provision of a futuristic solution in the Problem to Solution Model of Textual Patterning acts as a pointer to the present situation even if it was not stated expressly and the use specificity in the general to specific model acts as a form of reinforcement on the information value of the general statement.
A pilot process to identify and switch high-risk warfarin patients to direct oral anticoagulants
Authors: Lee Samson C. , Groce III James B. , Kim Jennifer J.
Published: September 2017

Objective: To pilot a process for identifying and switching high-risk warfarin patients to direct oral anticoagulants (DOACs) in nonvalvular atrial fibrillation (AF) or venous thromboembolism (VTE).Methods: A pharmacy resident identified high-risk warfarin patients using three criteria. The resident reviewed medical charts, communicated recommendations to the primary care physician (PCP), and scheduled patients for appointments to switch to DOACs. Patients were followed every 1 to 3 months after initiating DOACs. The primary outcome of the study was the percentage of high-risk warfarin patients before and after process implementation. Secondary outcomes at 6 months included bleeding or thrombotic events, patient-reported side effects, recommendation acceptance rates, adherence rates, clinic time in therapeutic range (TTR), and patient satisfaction.Results: Out of 76 patients evaluated, 22.4% were identified as high-risk using the pre-specified criteria. After program implementation, this percentage was reduced to 9.2%. No significant adverse events occurred by 3-month follow-up, and 100% of recommendations were accepted by physicians. Adherence rates and clinic TTR also improved after implementation (87.5% to 94% and 60.9% to 81.1%, respectively). Overall, patients reported satisfaction with switching from warfarin to DOAC.Conclusions: A pilot process was successful in reducing the percentage of high-risk warfarin patients by switching to DOAC therapy.
Het vennootschappelijk belang: de beschermheer van het nationale belang?
Authors: Nijk R.M.
Published: September 2017

Het vennootschappelijk belang: de beschermheer van het nationale belang?

In deze bijdrage onderzoekt de auteur in hoeverre een Nederlandse beursgenoteerde NV het nationale belang kan inroepen tegen een openbaar bod dat is gedaan door een buitenlandse entiteit. Hiertoe bekijkt hij in hoeverre het vennootschappelijk belang het nationale belang omvat.
A Low-Cost Library Database Solution
Authors: England Mark , Joseph Lura , Schlect Nem W.
Published: September 2017

Two locally created databases are made available to the world via the Web using an inexpensive but highly functional search engine created in-house. The technology consists of a microcomputer running UNIX to serve relational databases. CGI forms created using the programming language Perl offer flexible interface designs for database users and database maintainers.
Digital Resource Sharing and Library Consortia in Italy
Authors: Giordano Tommaso
Published: September 2017

Interlibrary cooperation in Italy is a fairly recent and not very widespread practice. Attention to the topic was aroused in the eighties with the Italian library network project. More recently, under the impetus toward technological innovation, there has been renewed (and more pragmatic) interest in cooperation in all library sectors. Sharing electronic resources is the theme of greatest interest today in university libraries, where various initiatives are aimed at setting up consortia to purchase licenses and run digital products. A number of projects in hand are described, and emerging trends analyzed.
Consortia Building: A Handshake and a Smile, Island Style
Authors: Cutright Patricia
Published: September 2017

In the evaluation of consortia and what constitutes these entities the discussion runs the gamut. From small, loosely knit groups who are interested in cooperation for the sake of improving services to large membership driven organizations addressing multiple interests, all recognize the benefits of partnerships. The Federated States of Micronesia are located in the western Pacific Ocean and cover 3.2 million square miles. Throughout this scattering of small islands exists an enthusiastic library community of staff and users that have changed the outlook of libraries since 1991. Motivated by the collaboratvie ef orts of this group, a project has unfolded over the past year that will further enhance library services through staff training and education while utilizing innovative technology. In assessing the library needs of the region this group crafted the document "The Federated States of Micronesia Library Services Plan, 1999-2003," which coalesces the concepts, goals, and priorities put forward by a broad-based contingency of librarians. The compilation of the plan and its implementation demonstrate an understanding of the issues and exhibit the ingenuity, creativity, and willingness to solve problems on a grand scale addressing the needs of all libraries in this vast Pacific region.
New Strategies in Library Services Organization: Consortia University Libraries in Spain
Authors: Barrionuevo Miguel Duarte
Published: September 2017

New political, economic, and technological developments, as well as the growth of information markets, in Spain have created a foundation for the creation of library consortia. The author describes the process by which different regions in Spain have organized university library consortia.
Book Reviews
Authors: Zillner Tom , Morgan Eric Lease
Published: September 2017

Book Reviews
Tinglysning. Who cares i Peter Adolphsens roman “Brummstein”?
Authors: Høgh Søren Langager
Published: September 2017

Søren Langager Høgh: “Tinglysning* – Who Cares in Peter Adolphsen’s novel Brummstein (2003)?”Focusing on the concept of care (including matters-of-care, ethos of care, care giver/care taker, cute [kær], sorrow, diligence and the new term GeoWei) this paper argues that Peter Adolphsen’s novel Brummstein (2003) is a speculative accomplishment in the politics of causality. The main trajectory of the novel focuses on a stone that is given the necessary space to be included in the Social, which we in an uncaring world view tend to reserve for humans. Based on Maria Puig de Bellacasa’s reading of Bruno Latour’s notion of matters-of-concern, I propose to interpret the role text is given in the practice of caring for neglected things in Brummstein as a quality of literature.* “Tinglysning” is a old Danish word used in present language of property law, meaning both 1) land registration, 2) to shed light on the thing and 3) to shed light on a concern in a political gathering i.e. literally to make things public
The complete chloroplast genome ofCinnamomum camphoraand its comparison with relatedLauraceaespecies
Authors: Chen Caihui , Zheng Yongjie , Liu Sian , Zhong Yongda , Wu Yanfang , Li Jiang , Xu Li-An , Xu Meng
Published: September 2017

Cinnamomum camphora, a member of theLauraceaefamily, is a valuable aromatic and timber tree that is indigenous to the south of China and Japan. All parts ofCinnamomum camphorahave secretory cells containing different volatile chemical compounds that are utilized as herbal medicines and essential oils. Here, we reported the complete sequencing of the chloroplast genome ofCinnamomum camphorausing illumina technology. The chloroplast genome ofCinnamomum camphorais 152,570 bp in length and characterized by a relatively conserved quadripartite structure containing a large single copy region of 93,705 bp, a small single copy region of 19,093 bp and two inverted repeat (IR) regions of 19,886 bp. Overall, the genome contained 123 coding regions, of which 15 were repeated in the IR regions. An analysis of chloroplast sequence divergence revealed that the small single copy region was highly variable among the different genera in theLauraceaefamily. A total of 40 repeat structures and 83 simple sequence repeats were detected in both the coding and non-coding regions. A phylogenetic analysis indicated thatCalycanthusis most closely related toLauraceae, both being members ofLaurales, which forms a sister group toMagnoliids. The complete sequence of the chloroplast ofCinnamomum camphorawill aid in in-depth taxonomical studies of theLauraceaefamily in the future. The genetic sequence information will also have valuable applications for chloroplast genetic engineering.
APE1/Ref‐1 knockdown in pancreatic ductal adenocarcinoma – characterizing gene expression changes and identifying novel pathways using single‐cellRNAsequencing
Authors: Shah Fenil , Goossens Emery , Atallah Nadia M. , Grimard Michelle , Kelley Mark R. , Fishel Melissa L.
Published: September 2017

Apurinic/apyrimidinic endonuclease 1/redox factor‐1 (APE1/Ref‐1 orAPE1) is a multifunctional protein that regulates numerous transcription factors associated with cancer‐related pathways. BecauseAPE1 is essential for cell viability, generation ofAPE1‐knockout cell lines and determining a comprehensive list of genes regulated byAPE1 has not been possible. To circumvent this challenge, we utilized single‐cellRNAsequencing to identify differentially expressed genes (DEGs) in relation toAPE1 protein levels within the cell. Using a straightforward yet novel statistical design, we identified 2837 genes whose expression is significantly changed followingAPE1 knockdown. Using this gene expression profile, we identified multiple new pathways not previously linked toAPE1, including theEIF2 signaling and mechanistic target of Rapamycin pathways and a number of mitochondrial‐related pathways. We demonstrate thatAPE1 has an effect on modifying gene expression up to a threshold ofAPE1 expression, demonstrating that it is not necessary to completely knockoutAPE1 in cells to accurately studyAPE1 function. We validated the findings using a selection of the DEGs along with siRNAknockdown andqRT‐PCR. Testing additional patient‐derived pancreatic cancer cells reveals particular genes (ITGA1,TNFAIP2,COMMD7,RAB3D) that respond toAPE1 knockdown similarly across all the cell lines. Furthermore, we verified that the redox function ofAPE1 was responsible for driving gene expression of mitochondrial genes such asPRDX5and genes that are important for proliferation such asSIPA1andRAB3Dby treating withAPE1 redox‐specific inhibitor,APX3330. Our study identifies several novel genes and pathways affected byAPE1, as well as tumor subtype specificity. These findings will allow for hypothesis‐driven approaches to generate combination therapies using, for example,APE1 inhibitorAPX3330 with other approvedFDAdrugs in an innovative manner for pancreatic and other cancer treatments.
Tropical Dominance of N2 Fixation in the North Atlantic Ocean
Authors: Marconi Dario , Sigman Daniel M. , Casciotti Karen L. , Campbell Ethan C. , Alexandra Weigand M. , Fawcett Sarah E. , Knapp Angela N. , Rafter Patrick A. , Ward Bess B. , Haug Gerald H.
Published: September 2017

To investigate the controls on N2 fixation and the role of the Atlantic in the global ocean's fixed nitrogen (N) budget, Atlantic N2 fixation is calculated by combining meridional nitrate fluxes across World Ocean Circulation Experiment sections with observed nitrate 15N/14N differences between northward and southward transported nitrate. N2 fixation inputs of 27.1 ± 4.3 Tg N/yr and 3.0 ± 0.5 Tg N/yr are estimated north of 11°S and 24°N, respectively. That is, ~90% of the N2 fixation in the Atlantic north of 11°S occurs south of 24°N in a region with upwelling that imports phosphorus (P) in excess of N relative to phytoplankton requirements. This suggests that, under the modern iron‐rich conditions of the equatorial and North Atlantic, N2 fixation occurs predominantly in response to P‐bearing, N‐poor conditions. We estimate a N2 fixation rate of 30.5 ± 4.9 Tg N/yr north of 30°S, implying only 3 Tg N/yr between 30° and 11°S, despite evidence of P‐bearing, N‐poor surface waters in this region as well; this is consistent with iron limitation of N2 fixation in the South Atlantic. Since the ocean flows through the Atlantic surface in <2,500 years, similar to the residence time of oceanic fixed N, Atlantic N2 fixation can stabilize the N‐to‐P ratio of the global ocean. However, the calculated rate of Atlantic N2 fixation is a small fraction of global ocean estimates for either N2 fixation or fixed N loss. This suggests that, in the modern ocean, an approximate balance between N loss and N2 fixation is achieved within the combined Indian and Pacific basins.
Postinjection Normal Closure of Fractures as a Mechanism for Induced Seismicity
Authors: Ucar E. , Berre I. , Keilegavlen E.
Published: September 2017

Understanding the controlling mechanisms underlying injection‐induced seismicity is important for optimizing reservoir productivity and addressing seismicity‐related concerns related to hydraulic stimulation in Enhanced Geothermal Systems. Hydraulic stimulation enhances permeability through elevated pressures, which cause normal deformations and the shear slip of preexisting fractures. Previous experiments indicate that fracture deformation in the normal direction reverses as the pressure decreases, e.g., at the end of stimulation. We hypothesize that this normal closure of fractures enhances pressure propagation away from the injection region and significantly increases the potential for postinjection seismicity. To test this hypothesis, hydraulic stimulation is modeled by numerically coupling flow in the fractures and matrix, fracture deformation, and matrix deformation for a synthetic reservoir in which the flow and mechanics are strongly affected by a complex three‐dimensional fracture network. The role of the normal closure of fractures is verified by comparing simulations conducted with and without the normal closure effect.
Wave‐Related Reynolds Number Parameterizations of CO2 and DMS Transfer Velocities
Authors: Brumer Sophia E. , Zappa Christopher J. , Blomquist Byron W. , Fairall Christopher W. , Cifuentes‐Lorenzen Alejandro , Edson James B. , Brooks Ian M. , Huebert Barry J.
Published: September 2017

Predicting future climate hinges on our understanding of and ability to quantify air‐sea gas transfer. The latter relies on parameterizations of the gas transfer velocity k, which represents physical mass transfer mechanisms and is usually parameterized as a nonlinear function of wind forcing. In an attempt to reduce uncertainties in k, this study explores empirical parameterizations that incorporate both wind speed and sea state dependence via wave‐wind and breaking Reynolds numbers, RH and RB. Analysis of concurrent eddy covariance gas transfer and measured wavefield statistics supplemented by wave model hindcasts shows for the first time that wave‐related Reynolds numbers collapse four open ocean data sets that have a wind speed dependence of CO2 transfer velocity ranging from lower than quadratic to cubic. Wave‐related Reynolds number and wind speed show comparable performance for parametrizing dimethyl sulfide (DMS) which, because of its higher solubility, is less affected by bubble‐mediated exchange associated with wave breaking.
Global Three‐Dimensional Simulation of Earth's Dayside Reconnection Using a Two‐Way Coupled Magnetohydrodynamics With Embedded Particle‐in‐Cell Model: Initial Results
Authors: Chen Yuxi , Tóth Gábor , Cassak Paul , Jia Xianzhe , Gombosi Tamas I. , Slavin James A. , Markidis Stefano , Peng Ivy Bo , Jordanova Vania K. , Henderson Michael G.
Published: September 2017

We perform a three‐dimensional (3‐D) global simulation of Earth's magnetosphere with kinetic reconnection physics to study the flux transfer events (FTEs) and dayside magnetic reconnection with the recently developed magnetohydrodynamics with embedded particle‐in‐cell model. During the 1 h long simulation, the FTEs are generated quasi‐periodically near the subsolar point and move toward the poles. We find that the magnetic field signature of FTEs at their early formation stage is similar to a “crater FTE,” which is characterized by a magnetic field strength dip at the FTE center. After the FTE core field grows to a significant value, it becomes an FTE with typical flux rope structure. When an FTE moves across the cusp, reconnection between the FTE field lines and the cusp field lines can dissipate the FTE. The kinetic features are also captured by our model. A crescent electron phase space distribution is found near the reconnection site. A similar distribution is found for ions at the location where the Larmor electric field appears. The lower hybrid drift instability (LHDI) along the current sheet direction also arises at the interface of magnetosheath and magnetosphere plasma. The LHDI electric field is about 8 mV/m, and its dominant wavelength relative to the electron gyroradius agrees reasonably with Magnetospheric Multiscale (MMS) observations.
Neutron Monitors and Cosmogenic Isotopes as Cosmic Ray Energy‐Integration Detectors: Effective Yield Functions, Effective Energy, and Its Dependence on the Local Interstellar Spectrum
Authors: Asvestari Eleanna , Gil Agnieszka , Kovaltsov Gennady A. , Usoskin Ilya G.
Published: September 2017

The method of assessment of galactic cosmic rays (GCR) variability over different timescales, using energy‐integrating ground‐based detectors such as a neutron monitor and cosmogenic isotopes 10Be and 14C stored in natural archives is revisited here. The effective yield functions for cosmogenic 14C (globally mixed in the atmosphere) and 10Be (realistically deposited in the polar region) are calculated and provided, in a tabulated form, in the supporting information. The effective energy of a detector is redefined so that the variability of the flux of GCR particles at this energy is equal to that of the detector's count rate. The effective energy is found as 11–12 GeV/nucleon for the standard polar neutron monitor, and 6–7 GeV/nucleon and 5.5–6 GeV/nucleon for 14C and 10Be, respectively. New “calibration” relations between the force‐field modulation potentials, based on different models of local interstellar spectra (LIS) are provided. While such relations are typically based on refitting the modeled cosmic ray spectra with a prescribed LIS model, the method introduced here straightforwardly accounts for the exact type of the detector used to assess the spectrum. The relations are given separately for ground‐based neutron monitors and cosmogenic isotopes. This work allows for harmonization of different works related to variability of galactic cosmic ray flux in the vicinity of Earth, on long‐term scale.
Seasonal‐Scale Dating of a Shallow Ice Core From Greenland Using Oxygen Isotope Matching Between Data and Simulation
Authors: Furukawa Ryoto , Uemura Ryu , Fujita Koji , Sjolte Jesper , Yoshimura Kei , Matoba Sumito , Iizuka Yoshinori
Published: September 2017

A precise age scale based on annual layer counting is essential for investigating past environmental changes from ice core records. However, subannual scale dating is hampered by the irregular intraannual variabilities of oxygen isotope (δ18O) records. Here we propose a dating method based on matching the δ18O variations between ice core records and records simulated by isotope‐enabled climate models. We applied this method to a new δ18O record from an ice core obtained from a dome site in southeast Greenland. The close similarity between the δ18O records from the ice core and models enables correlation and the production of a precise age scale, with an accuracy of a few months. A missing δ18O minimum in the 1995/1996 winter is an example of an indistinct δ18O seasonal cycle. Our analysis suggests that the missing δ18O minimum is likely caused by a combination of warm air temperature, weak moisture transport, and cool ocean temperature. Based on the age scale, the average accumulation rate from 1960 to 2014 is reconstructed as 1.02 m yr−1 in water equivalent. The annual accumulation rate shows an increasing trend with a slope of 3.6 mm yr−1, which is mainly caused by the increase in the autumn accumulation rate of 2.6 mm yr−1. This increase is likely linked to the enhanced hydrological cycle caused by the decrease in Arctic sea ice area. Unlike the strong seasonality of precipitation amount in the ERA reanalysis data in the southeast dome region, our reconstructed accumulation rate suggests a weak seasonality.
AERONET‐Based Nonspherical Dust Optical Models and Effects on the VIIRS Deep Blue/SOAR Over Water Aerosol Product
Authors: Lee Jaehwa , Hsu N. Christina , Sayer Andrew M. , Bettenhausen Corey , Yang Ping
Published: September 2017

Aerosol Robotic Network (AERONET)‐based nonspherical dust optical models are developed and applied to the Satellite Ocean Aerosol Retrieval (SOAR) algorithm as part of the Version 1 Visible Infrared Imaging Radiometer Suite (VIIRS) NASA “Deep Blue” aerosol data product suite. The optical models are created using Version 2 AERONET inversion data at six distinct sites influenced frequently by dust aerosols from different source regions. The same spheroid shape distribution as used in the AERONET inversion algorithm is assumed to account for the nonspherical characteristics of mineral dust, which ensures the consistency between the bulk scattering properties of the developed optical models and the AERONET‐retrieved microphysical and optical properties. For the Version 1 SOAR aerosol product, the dust optical model representative for Capo Verde site is used, considering the strong influence of Saharan dust over the global ocean in terms of amount and spatial coverage. Comparisons of the VIIRS‐retrieved aerosol optical properties against AERONET direct‐Sun observations at five island/coastal sites suggest that the use of nonspherical dust optical models significantly improves the retrievals of aerosol optical depth (AOD) and Ångström exponent by mitigating the well‐known artifact of scattering angle dependence of the variables, which is observed when incorrectly assuming spherical dust. The resulting removal of these artifacts results in a more natural spatial pattern of AOD along the transport path of Saharan dust to the Atlantic Ocean; that is, AOD decreases with increasing distance transported, whereas the spherical assumption leads to a strong wave pattern due to the spurious scattering angle dependence of AOD.
Three‐Dimensional Evolution of the Early Paleozoic Western Laurentian Margin: New Insights From Detrital Zircon U‐Pb Geochronology and Hf Isotope Geochemistry of the Harmony Formation of Nevada
Authors: Linde G. M. , Trexler J. H. , Cashman P. H. , Gehrels G. , Dickinson W. R.
Published: September 2017

Uranium‐lead (U‐Pb) geochronology and Hafnium (Hf) isotope geochemistry of detrital zircons of the Harmony Formation of north central Nevada provide new insights into the tectonic evolution of the Late Paleozoic western Laurentian margin. Using laser‐ablation inductively coupled plasma mass spectrometry, 10 arenite samples were analyzed for U‐Pb ages, and 8 of these samples were further analyzed for Hf isotope ratios. Three of the sampled units have similar U‐Pb age peaks and Hf isotope ratios, including a 1.0–1.4 Ga peak with εHf values of +12 to −3 and a 2.5–2.7 Ga peak with εHf values of +7 to −5. The remaining seven samples differ significantly from these three, but are similar to one another; having age peaks of 1.7–1.9 Ga with εHf of +10 to −20 and age peaks of 2.3–2.7 Ga with εHf of +6 to −8. The data confirm the subdivision of the Harmony Formation into two petrofacies: quartzose (Harmony A) and feldspathic (Harmony B). The three samples with 1.0–1.4 and 2.5–2.7 Ga peaks are the Harmony A, which originated in the central Laurentian craton. The other seven samples are the Harmony B, which originated in eastern Alberta‐western Saskatchewan, north of the Harmony A source. We propose that all Harmony Formation strata were deposited near eastern Alberta and subsequently tectonically interleaved with Roberts Mountains allochthon strata. We interpret that the entire package was tectonically transported south along the western Laurentian margin and then emplaced eastward onto the craton during the Late Devonian‐Early Mississippian Antler orogeny.
Characterization of auxiliary iron–sulfur clusters in a radical S‐adenosylmethionine enzyme PqqE from Methylobacterium extorquens AM1
Authors: Saichana Natsaran , Tanizawa Katsuyuki , Ueno Hiroshi , Pechoušek Jiří , Novák Petr , Frébortová Jitka
Published: September 2017

PqqE is a radical S‐adenosyl‐l‐methionine (SAM) enzyme that catalyzes the initial reaction of pyrroloquinoline quinone (PQQ) biosynthesis. PqqE belongs to the SPASM (subtilosin/PQQ/anaerobic sulfatase/mycofactocin maturating enzymes) subfamily of the radical SAM superfamily and contains multiple Fe–S clusters. To characterize the Fe–S clusters in PqqE from Methylobacterium extorquens AM1, Cys residues conserved in the N‐terminal signature motif (CX3CX2C) and the C‐terminal seven‐cysteine motif (CX9–15GX4CXnCX2CX5CX3CXnC; n = an unspecified number) were individually or simultaneously mutated into Ser. Biochemical and Mössbauer spectral analyses of as‐purified and reconstituted mutant enzymes confirmed the presence of three Fe–S clusters in PqqE: one [4Fe–4S]2+ cluster at the N‐terminal region that is essential for the reductive homolytic cleavage of SAM into methionine and 5′‐deoxyadenosyl radical, and one each [4Fe–4S]2+ and [2Fe–2S]2+ auxiliary clusters in the C‐terminal SPASM domain, which are assumed to serve for electron transfer between the buried active site and the protein surface. The presence of [2Fe–2S]2+ cluster is a novel finding for radical SAM enzyme belonging to the SPASM subfamily. Moreover, we found uncommon ligation of the auxiliary [4Fe–4S]2+ cluster with sulfur atoms of three Cys residues and a carboxyl oxygen atom of a conserved Asp residue.
A New Passivation Route Leading to Over 8% Efficient PbSe Quantum‐Dot Solar Cells via Direct Ion Exchange with Perovskite Nanocrystals
Authors: Zhang Zhilong , Chen Zihan , Yuan Lin , Chen Weijian , Yang Jianfeng , Wang Bo , Wen Xiaoming , Zhang Jianbing , Hu Long , Stride John A. , Conibeer Gavin J. , Patterson Robert J. , Huang Shujuan
Published: September 2017

Colloidal quantum dots (QDs) are promising candidate materials for photovoltaics (PV) owing to the tunable bandgap and low‐cost solution processability. Lead selenide (PbSe) QDs are particularly attractive to PV applications due to the efficient multiple‐exciton generation and carrier transportation. However, surface defects arising from the oxidation of the PbSe QDs have been the major limitation for their development in PV. Here, a new passivation method for chlorinated PbSe QDs via ion exchange with cesium lead halide (Br, I) perovskite nanocrystals is reported. The surface chloride ions on the as‐synthesized QDs can be partially exchanged with bromide or iodide ions from the perovskite nanocrystals, hence forming a hybrid halide passivation. Consistent with the improved photoluminescence quantum yield, the champion PV device fabricated with these PbSe QDs achieves a PCE of 8.2%, compared to 7.3% of that fabricated with the untreated QDs. This new method also leads to devices with excellent air‐stability, retaining at least 93% of their initial PCEs after being stored in ambient conditions for 57 d. This is considered as the first reported PbSe QD solar cell with a PCE of over 8% to date.
Formation of Ni–Fe Mixed Diselenide Nanocages as a Superior Oxygen Evolution Electrocatalyst
Authors: Nai Jianwei , Lu Yan , Yu Le , Wang Xin , Lou Xiong Wen (David)
Published: September 2017

Exploring effective electrocatalysts is a crucial requirement for boosting the efficiency of water splitting to obtain clean fuels. Here, a self‐templating strategy is reported to synthesize Ni–Fe mixed diselenide cubic nanocages for the electrocatalytic oxygen evolution reaction (OER). The diselenide nanocages are derived from corresponding Prussian‐blue analog nanocages, which are first obtained by treating the nanocube precursor with a site‐selective ammonia etchant. The resulting Ni–Fe mixed diselenide nanocages perform as a superior OER electrocatalyst, which affords a current density of 10 mA cm−2 at a small overpotential of 240 mV; a high current density, mass activity, and turnover frequency of 100 mA cm−2, 1000 A g−1, and 0.58 s−1, respectively, at the overpotential of 270 mV; a Tafel slope as small as 24 mV dec−1; and excellent stability in alkaline medium.
A Case Study of Thiourea‐Assisted Iminium Formation by Hydroxyl Anion Binding: Kinetic, Spectroscopic and Computational Evidences
Authors: Juste‐Navarro Veronica , Prieto Liher , Delso Ignacio , Manzano Rubén , Tejero Tomas , Reyes Efraim , Vicario Jose L. , Merino Pedro
Published: September 2017

The experimental and computational study of the mechanism of the iminium‐organocatalyzed formation of N‐hydroxypyrrolidines from nitrones, revealed up to three activation levels of the Schreiner's thiourea used as co‐catalyst, i.e: (i) formation of the iminium ion through hydroxyl anion recognition forming a stable ion pair; (ii) enolization of the nitrone through a H‐bond network and (iii) activation of the nitrone moiety towards the final ring closure. The computational model supports the mechanism and the catalytic cycle. This mechanistic rationale is supported by the lack of reactivity of preformed iminium ion with the nitrone in the absence of thiourea‐hydroxyl complex and the observed reactivity when a complex thiourea‐tetrabutylammonium hydroxide is added.

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Photodetectors Based on Organic–Inorganic Hybrid Lead Halide Perovskites
Authors: Zhou Jiachen , Huang Jia
Published: September 2017

Recent years have witnessed skyrocketing research achievements in organic–inorganic hybrid lead halide perovskites (OIHPs) in the photovoltaic field. In addition to photovoltaics, more and more studies have focused on OIHPs‐based photodetectors in the past two years, due to the remarkable optoelectronic properties of OIHPs. This article summarizes the latest progress in this research field. To begin with, the factors influencing the performance of photodetectors are discussed, including both internal and external factors. In particular, the channel width and the incident power intensities should be taken into account to precisely and objectively evaluate and compare the output performance of different photodetectors. Next, photodetectors fabricated on single‐component perovskites in terms of different micromorphologies are discussed, namely, 3D thin‐film and single crystalline, 2D nanoplates, 1D nanowires, and 0D nanocrystals, respectively. Then, bilayer structured perovskite‐based photodetectors incorporating inorganic and organic semiconductors are discussed to improve the optoelectronic performance of their pristine counterparts. Additionally, flexible OIHPs‐based photodetectors are highlighted. Finally, a brief conclusion and outlook is given on the progress and challenges in the field of perovskites‐based photodetectors.
CuI/I2‐Mediated Intramolecular Oxidative Cyclization Reaction of N‐(2‐pyridyl)amidines by the Direct Double C−H Functionalization of a C(sp3)−H Bond
Authors: Yi Fengping , Zhang Songxing , Zhang Lirong , Yi Weiyin , Yu Rui
Published: September 2017

A facile approach to a rare class of 3,3‐disubstituted 2‐iminoimidazo[1,2‐a]‐pyridines bearing a hydroxyl group at the 3 position in good to excellent yields from N‐(2‐pyridyl)amidines substrates in the presence of CuI/I2/KI/KOtBu is described. According to the investigation, the use of a Cu catalyst and the presence of sulfonyl groups in the substrates has a remarkable influence on the success of the oxidative cyclization reaction. Moreover, the oxygen source of the hydroxyl group may be from the incorporation of water in the reaction system or KOtBu. The successful implementation of the reaction further indicates that amidines have abundant reactivity under various reaction conditions. The methodology is operationally simple and has a broad substrate scope.
Structures of the Heme Acquisition Protein HasA with Iron(III)‐5,15‐Diphenylporphyrin and Derivatives Thereof as an Artificial Prosthetic Group
Authors: Uehara Hiromu , Shisaka Yuma , Nishimura Tsubasa , Sugimoto Hiroshi , Shiro Yoshitsugu , Miyake Yoshihiro , Shinokubo Hiroshi , Watanabe Yoshihito , Shoji Osami
Published: September 2017

Iron(III)‐5,15‐diphenylporphyrin and several derivatives were accommodated by HasA, a heme acquisition protein secreted by Pseudomonas aeruginosa, despite possessing bulky substituents at the meso position of the porphyrin. Crystal structure analysis revealed that the two phenyl groups at the meso positions of porphyrin extend outside HasA. It was shown that the growth of P. aeruginosa was inhibited in the presence of HasA coordinating the synthetic porphyrins under iron‐limiting conditions, and that the structure of the synthetic porphyrins greatly affects the inhibition efficiency.
Characterization of Doubly Ionic Hydrogen Bonds in Protic Ionic Liquids by NMR Deuteron Quadrupole Coupling Constants: Differences to H‐bonds in Amides, Peptides, and Proteins
Authors: Khudozhitkov Alexander E. , Stange Peter , Golub Benjamin , Paschek Dietmar , Stepanov Alexander G. , Kolokolov Daniil I. , Ludwig Ralf
Published: September 2017

We present the first deuteron quadrupole coupling constants (DQCCs) for selected protic ionic liquids (PILs) measured by solid‐state NMR spectroscopy. The experimental data are supported by dispersion‐corrected density functional theory (DFT‐D3) calculations and molecular dynamics (MD) simulations. The DQCCs of the N−D bond in the triethylammonium cations are the lowest reported for deuterons in PILs, indicating strong hydrogen bonds between ions. The NMR coupling parameters are compared to those in amides, peptides, and proteins. The DQCCs show characteristic behavior with increasing interaction strength of the counterion and variation of the H‐bond motifs. We report the similar presence of the quadrupolar splitting pattern and the narrow liquid line in the NMR spectra over large temperature ranges, indicating the heterogeneous nature of PILs.
The Quest for Mononuclear Gold(II) and Its Potential Role in Photocatalysis and Drug Action
Authors: Heinze Katja
Published: September 2017

The chemistry of gold strongly focuses on the ubiquitous oxidation states +I and +III. The intermediate oxidation state +II is generally avoided in mononuclear gold species. In recent years, gold(II) has been increasingly suggested as a key intermediate in artificial photosynthesis systems, with gold(III) moieties acting as electron acceptors, as well as in gold‐catalyzed photoredox catalysis and radical chemistry. This Minireview provides a concise summary of confirmed and characterized mononuclear open‐shell gold(II) complexes. Recent findings on structural motifs and reactivity patterns will be discussed. Exciting developments in the fields of photosynthesis, photocatalysis, and potential roles in medicinal chemistry will be outlined.
Forest‐based resources as fillers in biobased polyurethane foams
Authors: de Avila Delucis Rafael , Magalhães Washington Luiz Esteves , Petzhold Cesar Liberato , Amico Sandro Campos
Published: September 2017

Six fillers from forestry wastes (wood, bark, cones and needles from young pine trees, kraft lignin, and recycled paper sludge from industry wastes) were incorporated into polyurethane (PU)‐based foams prepared via free‐rise pouring method. Variable filler contents (1, 5, and 10 wt %) and NCO/OH ratios (0.6, 0.9, and 1.2) were investigated. A simple mixture (1:3) of castor oil and crude glycerin (byproduct from biodiesel production) was used as biobased polyol. The foam composites were investigated through spectroscopy, morphological, mechanical, and hygroscopic analyses. The addition of fillers decreased water uptake and yielded rigid PU systems with more homogenous cell structure. The 1% and 5% reinforcement wood were the most effective among the studied compositions, with better mechanical and hygroscopic performance, probably due the higher compatibility of the wood with the PU system, which promote urethanic bonds between filler and isocyanate, as indicated by wet chemical results and micrographs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45684.
Evaluation of oilfield‐produced water treated with a prepared magnetic inorganic polymer: Poly(silicate aluminum)/magnetite
Authors: Cai Dan , Zhang Tailiang , Zhang Fangjie
Published: September 2017

In this study, novel coagulant poly(silicate aluminum)/Fe3O4 nanoparticles (PFeNPs) were prepared via magnetic iron oxide nanoparticles (FeNPs) modified by poly(silicate aluminum) (PSA). The physiochemical properties of the PFeNPs were investigated with Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, and ζ‐potential metric analysis. The effect of the aging time on the Al distribution of the PFeNPs was analyzed by the Al‐Ferron timed complex colorimetric method. Oilfield‐produced water was used for the assessment of the coagulation performances. The fractal dimensions, formation, breakage, and regrowth of the flocs were studied in turn. The experimental results show that the PFeNPs exhibited a porous layer of a net structure, and the PSA grafted onto the PFeNPs via SiOFe enhanced the positive charge of the FeNPs. Meanwhile, the coagulation performance of the PFeNPs on total organic carbon, the turbidity, and the calcium removal were beyond 98%. In addition, the moisture content of the flocs derived from the PFeNPs was 68.7% (it is normally > 98%). We found that the compactness of the flocs derived from the PFeNPs was far greater than those of PSA. This will provide new sight into the preparation of magnetic single‐phase inorganic polymer coagulants. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45735.
Ethical dilemma: Deception dynamics in computer‐mediated group communication
Authors: Ho Shuyuan Mary , Hancock Jeffrey T. , Booth Cheryl
Published: September 2017

Words symbolically represent communicative and behavioral intent, and can provide clues to a communicator's future actions in online communication. This paper describes a sociotechnical study conducted from 2008 through 2015 to identify deceptive communicative intent within group context as manifested in language‐action cues. Specifically, this study used an online team‐based game that simulates real‐world deceptive insider scenarios to examine several dimensions of group communication. First, we studied how language‐action cues differ between groups with and groups without a compromised actor. We also examine how these cues differ within groups in terms of the group members' individual and collective interactions with the compromised actor. Finally, we look at how the cues of compromised actors differ from those of noncompromised actors, and how communication behavior changes after an actor is presented with an ethical dilemma. The results of the study further our understanding of language‐action cues as indicators for unmasking a potential deceptive insider.