bluuebunny/crossref_metadata_2025_split huggingface dataset:
O lugar do tempo presente na aula de história: limites e possibilidades
Authors: Silva Daniel Pinha 
Published: May 2017

Reconhecendo a importância do tempo presente na conformação da história ensinada e da concepção moderna de história como um todo, o texto delineia a história desta centralidade, associada à tensão entre aproximação inevitável e necessidade de afastamento do enunciado historiográfico em relação à experiência política presente na qual está inserido. Em um segundo movimento, é feita uma análise das perspectivas contemporâneas sobre a questão, levando em conta 1. a ampliação do repertório de sujeitos, objetos e métodos da história, desde a segunda metade do século XX, questionando o paradigma eurocêntrico e a ideia de Civilização que lhe é intrínseca; 2. a ênfase no conceito de cidadania como mola mestra da historiografia escolar, cuja elasticidade é tributária deste novo arsenal de experiências e narrativas históricas; e 3. a cultura histórica da atualidade e sua ênfase presentista, desconfiada da possibilidade de projeção de futuros estáveis, mas com apreço pela memória e pelo passado em circulação social. Em suma, em face deste contexto de elaboração, difusão e usos de narrativas históricas, o artigo problematiza o lugar ocupado pelo tempo presente em aulas de história na escola, em seus limites e potencialidades. Por um lado, o tempo presente é tido como fundamental para conferir condições de inteligibilidade e produção de sentido histórico, adequado aos objetivos pedagógicos da história e seu propósito formador; por outro, apontam-se os limites de uma ênfase exclusivamente centrada no presente, incapaz de permitir a experiência do descentramento no tempo e a compreensão das permanências, da dimensão cumulativa e da longa duração histórica. Palavras-chave: História – Estudo e Ensino. Historiografia. Tempo presente.
THE LEVANT: ZONE OF CULTURE OR CONFLICT?
Authors: El-Youssef Samir 
Published: May 2017

Palestinian novelist Samir El-Youssef writes that the question in the title of this essay, “is the Levant a zone of conflict or culture?” is an ironic one indeed. Anyone with a token knowledge of the Levant, argues El-Youssef, knows that these lands are of both conflict and culture; the problem dwells in the fact that the people of the Levant need to be reminded that theirs is a land of great culture that deserves recognition and valorization as such. The author was born and brought up in Rashidiyyé—a Palestinian refugee camp in Southern Lebanon. Rashidiyyé, writes El-Youssef, was and still is as bad as a refugee camp could get. Yet, a mere fifteen minutes walk from the camp stood the ancient Phoenician port-city of Tyr; a harbour town housing the awesome vestiges of one of the greatest, most pacifist, most benevolent builders of civilization. El-Youssef concludes that "the refugee camp (in its indigence,) and the ancient city (in all its glory,) standing side by side, are a stark example of the Levant being both a land of conflict and culture."
FATHI YAKAN THE PIONEER OF ISLAMIC ACTIVISM IN LEBANON
Authors: Rabil Robert G. 
Published: May 2017

This article explores the ideology of Fathi Yakan, the pioneer of Sunni Islamism in Lebanon and a principal founder of the Islamist party al-­‐Jama'a al-­‐Islamiya. It also traces the establishment of al_Jama'a as the first organized Islamist party in Lebanon. As Secretary General of al-­‐Jama'a, Fathi Yakan blazed the ideological trail for Islamism's participation in Lebanon's political realm. Significantly, Yakan's political activism, in much the same vein as that of Druze "Socialist" Kamal Jumblat, was also more about removing Maronite hegemony over the state.
JEWISH-­ARAB RELATIONS THROUGH THE LENSE OF ISRAELI CINEMA; THEN AND NOW
Authors: Shepkaru Shmuel 
Published: May 2017

Israeli cinema has presented different aspects of the relationship between Israeli Jews and Arabs. These aspects encompass topics such as personal friendships and conflicts, homosexual and heterosexual affairs, gender issues, politics and wars, and questions of identity. This article focuses on the presentations of the relationships between Jews and Arabs and their desire for normalization and peace.
NAJI ATTALLAH’S CREW: STEREOTYPES OF JEWS, ARABS, AND AMERICANS IN EGYPT’S MOST-­‐WATCHED RAMADAN 2012 SOAP OPERA
Authors: Martin Amaya 
Published: May 2017

In addition to its strict fasting regiments, observed by practicing Muslims, the month of Ramadan has become known for its high viewership of serialized television programs throughout the Arabic-speaking world. During Ramadan - a month during which millions partake of festive fast breaking (Iftaar) gatherings after sundown - competition among television stations pull all the stops to attract the largest audiences possible, often by offering compelling seasonal soap operas featuring major local and pan-Arab actors.
HEBREW AND ARAMAIC ELEMENTS IN THE ISRAELI VERNACULAR CHRISTIAN-­‐ARABIC AND IN THE WRITTEN CHRISTIAN ARABIC OF PALESTINE, SYRIA, AND LEBANON
Authors: Bassal Ibrahim 
Published: May 2017

This essay examines the Hebrew and Aramaic residues in the Arabic vernacular spoken by Israeli Christians and the written Arabic of Christians in the Holy Land, Syria, and Lebanon. The corpus of the spoken Christian-Arabic under consideration here is based on cassette recordings of elderlies who live in Christian villages in northern Israel - namely in Fassuta, Me’ilya, Tarshiha, Bqe’a, Jiish, Kufir Yasif, Ekreth, Bir’im, Ibilleen and Shfa’amir.The corpus of the written Christian-Arabic being reviewed is based mainly on folk tales, poems, proverbs, dictionaries, Bible translations, books of interpretations, and liturgical sources.
Cooperative effects of tropomyosin on the dynamics of the actin filament
Authors: Khaitlina Sofia , Tsaplina Olga , Hinssen Horst 
Published: May 2017

Tropomyosin (Tpm) plays an important role in regulating the organisation and functions of the actin cytoskeleton. Here, we describe a new approach to analyse the effects of Tpm on actin dynamics. Using F‐actin proteolytically modified within the DNase‐binding loop (ECP‐actin), we show that Tpm binding almost completely suppresses the increased subunit exchange intrinsic for this F‐actin. The effect is both concentration‐dependent and cooperative, with half‐maximal inhibition observed at about a 1 : 50 Tpm : actin ratio. Tpm decreases not only the number concentration of ECP‐actin filaments, but also the rate of the filament subunit exchange. Our data suggest that Tpm regulates the dynamics of actin filaments by an allosteric strengthening of intermonomer contacts in the actin filament, and that this mechanism may be involved in the modulation of cytoskeletal dynamics.
Submarine landslides triggered by destabilization of high‐saturation hydrate anomalies
Authors: Handwerger Alexander L. , Rempel Alan W. , Skarbek Rob M. 
Published: May 2017

AbstractSubmarine landslides occur along continental margins at depths that often intersect the gas hydrate stability zone, prompting suggestions that slope stability may be affected by perturbations that arise from changes in hydrate stability. Here we develop a numerical model to identify the conditions under which the destabilization of hydrates results in slope failure. Specifically, we focus on high‐saturation hydrate anomalies at fine‐grained to coarse‐grained stratigraphic boundaries that can transmit bridging stresses that decrease the effective stress at sediment contacts and disrupt normal sediment consolidation. We evaluate slope stability before and after hydrate destabilization. Hydrate anomalies act to significantly increase the overall slope stability due to large increases in effective cohesion. However, when hydrate anomalies destabilize there is a loss of cohesion and increase in effective stress that causes the sediment grains to rapidly consolidate and generate pore pressures that can either trigger immediate slope failure or weaken the surrounding sediment until the pore pressure diffuses away. In cases where failure does not occur, the sediment can remain weakened for months. In cases where failure does occur, we quantify landslide dynamics using a rate and state frictional model and find that landslides can display either slow or dynamic (i.e., catastrophic) motion depending on the rate‐dependent properties, size of the stress perturbation, and the size of the slip patch relative to a critical nucleation length scale. Our results illustrate the fundamental mechanisms through which the destabilization of gas hydrates can pose a significant geohazard.
Multianalytical provenance analysis of Eastern Ross Sea LGM till sediments (Antarctica): Petrography, geochronology, and thermochronology detrital data
Authors: Perotti Matteo , Andreucci Benedetta , Talarico Franco , Zattin Massimiliano , Langone Antonio 
Published: May 2017

AbstractIn order to reveal provenance of detrital sediments supplied by West Antarctic Ice Sheet (WAIS), 19 glaciomarine cores of Last Glacial Maximum age were analyzed from Eastern Ross Sea and Sulzberger Bay. Analytical techniques included petrographic analysis of gravel‐sized clasts, geochronology (zircon U‐Pb: Zrn‐UPb) and thermochronology (apatite fission track: AFT) of sand‐sized fractions. Petrographic analysis revealed a similarity with the lithologies presently exposed in western Marie Byrd Land (MBL), with major roles played by low‐grade metamorphic rocks and granitoids. Furthermore Zrn‐UPb and AFT data allowed to identify the ages of formation and cooling of sedimentary source area, consisting of Cambrian‐Precambrian basement (i.e., Swanson Formation in western MBL) which underwent at least two episodes of magma intrusion, migmatization and cooling during Devonian‐Carboniferous and Cretaceous‐Paleocene times. Scarcity of volcanic clasts in the region of Ross Sea along the front of West Antarctica Ice Streams in association with the occurrence of AFT Oligocene‐Pliocene dates suggests a localized tectonic exhumation of portions of MBL, as already documented for the opposite side of West Antarctic Rift System in the Transantarctic Mountains. Furthermore, a Zrn‐UPb and AFT population of Late Triassic‐Jurassic age indicates the presence of unexposed rocks that formed or metamorphosed at that time in the sedimentary source area, which could be identified in McAyeal Ice Stream and Bindschadler Ice Stream catchment areas.
Well‐preserved low thermal inertia ejecta deposits surrounding young secondary impact craters on Mars
Authors: Hill J. R. , Christensen P. R. 
Published: May 2017

AbstractFollowing the most recent updates to the Mars Odyssey Thermal Emission Imaging System daytime and nighttime infrared global mosaics, a colorized global map was produced that combines the thermophysical information from the nighttime infrared global mosaic with the morphologic context of the daytime infrared global mosaic. During the validation of this map, large numbers of low thermal inertia ejecta deposits surrounding small young impact craters were observed. A near‐global survey (60°N–60°S) identified 4024 of these low thermal inertia ejecta deposits, which were then categorized based on their apparent state of degradation. Mapping their locations revealed that they occur almost exclusively in regions with intermediate‐to‐high thermal inertias, with distinct clusters in northern Terra Sirenum, Solis Planum, and southwestern Daedalia Planum. High‐Resolution Imaging Science Experiment images show that the thermophysically distinct facies of the deposits are well correlated with the estimated average ejecta grain sizes, which decrease with radial distance from the crater. Comparisons with recent primary impact craters and secondary impact craters surrounding Zunil Crater show that the low thermal inertia ejecta deposits very closely resemble the secondary craters, but not the primary craters. We conclude that the low thermal inertia ejecta deposits are secondary impact crater ejecta deposits, many of which originated from the rayed crater primary impact events, and are both well preserved and easily identifiable due to the absence of dust cover and aeolian modification that would otherwise reduce the thermal contrast between the ejecta facies and the surrounding terrain.
Observed radiative cooling over the Tibetan Plateau for the past three decades driven by snow cover‐induced surface albedo anomaly
Authors: Chen Xiaona , Long Di , Hong Yang , Liang Shunlin , Hou Aizhong 
Published: May 2017

AbstractSeasonal snow cover on the Tibetan Plateau (TP) is a sensitive indicator of climate change. Unlike the decreasing snow cover extent and associated weakening of radiative cooling effects for the Northern Hemisphere during recent decades reported by previous studies, snow cover variability over the TP and its impact on the energy budget remain largely unknown. We defined the snow cover‐induced radiative forcing (SnRF) as the instantaneous perturbation to Earth's shortwave radiation at the top of the atmosphere (TOA) induced by the presence of snow cover. Here using satellite observations and a radiative kernel approach, we found slightly enhanced SnRF, i.e., a radiative cooling effect on the TP during the past three decades (1982–2014). However, this cooling effect weakened during 2001–2014 because of reduced snow cover at a rate of −0.61% decade−1 and land surface albedo at a rate of −0.72% decade−1. Changes in snow cover fraction are highly correlated with anomalies in land surface albedo (as) over the TP both spatially and temporally. Moreover, the SnRF is closely related to the direct observation of TOA shortwave flux anomalies (R2 = 0.54, p = 0.004) over the TP during 2001–2014. Despite the insignificant interannual variability in SnRF, its intra‐annual variability has intensified driven mostly by enhanced SnRF during the snow accumulation season but weakened SnRF during the melt season, indicating greater energy release during the transition between accumulation and melt seasons. This may pose a great challenge to snow meltwater use and flood prediction for transboundary rivers originating from the TP, such as the Brahmaputra River basin.
Salicylic Acid‐Catalyzed One‐Pot Hydrodeamination of Aromatic Amines by tert‐Butyl Nitrite in Tetrahydrofuran
Authors: Felipe‐Blanco Diego , Alonso Francisco , Gonzalez‐Gomez Jose C. 
Published: May 2017

AbstractA significant acceleration in the hydrodeamination of in situ formed diazonium salts (from aromatic amines) has been observed in the presence of 10‐mol% salicylic acid, using tetrahydrofuran as the hydrogen donor. The reaction proceeds efficiently at 20 °C for a wide range of substituted anilines, even at 10‐mmol scale, without any other additive. The same protocol has been adapted to the selective deuterodeamination of some aromatic amines. Control experiments clearly show that aryl radicals are involved in the reaction mechanism.magnified image
Asymmetric Synthesis of Functionalized Nitrophenols via a Copper(II)‐Mediated Bromination/Debromination Aromatization Sequence
Authors: Liu Xue‐Li , Zhang Xiao‐Long , Guo Yan‐Jun , Meng Chen‐Hong , Xia Ai‐Bao , Xu Dan‐Qian 
Published: May 2017

AbstractA stereospecific copper(II)‐mediated bromination/debromination aromatization sequence leading to functionalized nitrophenols from corresponding γ‐nitroketones is described. It provided a simple methodology for the construction of nitrophenols in moderate to good yields and moderate to high enantioselectivities.
Elektronische Struktur und magnetische Anisotropie eines ungesättigten Cyclopentadienyleisen(I)‐Komplexes mit 15 Valenzelektronen
Authors: Chakraborty Uttam , Demeshko Serhiy , Meyer Franc , Rebreyend Christophe , de Bruin Bas , Atanasov Mihail , Neese Frank , Mühldorf Bernd , Wolf Robert 
Published: May 2017

AbstractDer 15‐Valenzelektronen‐Komplex [CpArFe(IiPr2Me2)] (1, CpAr=C5(C6H4‐4‐Et)5; IiPr2Me2=1,3‐Diisopropyl‐4,5‐dimethylimidazolin‐2‐yliden) ist ausgehend von der Eisen(II)‐Vorstufe [CpArFe(μ‐Br)]2 in hohen Ausbeuten zugänglich. 57Fe‐Mößbauer‐ und EPR‐Daten, magnetische Messungen und Ab‐initio‐Ligandenfeldrechnungen deuten auf einen S=3/2‐Grundzustand mit einer großen negativen Nullfeldaufspaltung hin. Infolgedessen weist 1 magnetische Anisotropie mit einer effektiven Spinumkehrbarriere von Ueff=64 cm−1 auf. Zudem katalysiert 1 die Dehydrierung von Dimethylamin‐Boran unter Bildung von Tetramethyl‐1,3‐diaza‐2,4‐diboretan unter milden Bedingungen.
Privilegierte Strukturen neu betrachtet
Authors: Schneider Petra , Schneider Gisbert 
Published: May 2017

AbstractPrivilegierte Strukturen inspirieren den Entwurf von Substanzbibliotheken für die medizinische Chemie. Wir haben 1.4 Millionen bioaktive Substanzen hinsichtlich der Dominanz bestimmter chemischer Grundgerüste (“frameworks”) untersucht. Dabei diente die Shannon‐Entropie als ein quantitatives Maß für deren Promiskuität bezüglich der verschiedenen Targetfamilien. Diese Analyse offenbarte eine inverse Beziehung zwischen der Zahl an Wasserstoffbrückenakzeptoren und der beobachteten Promiskuität des Grundgerüsts. Des Weiteren scheinen sich strukturell einfache Gerüste besonders für Substanzbibliotheken mit unterschiedlichem Promiskuitätsgrad zu eignen, wohingegen sp3‐reiche heterozyklische Grundgerüste den Entwurf von Target‐fokussierten Bibliotheken ermöglichen. Die Resultate unserer Studie erlauben ein kritisches Hinterfragen von oft nur vermuteten besonderen Eigenschaften so genannter privilegierter Strukturen und weisen einen Weg zu deren systematischer Nutzung in der medizinischen Chemie.
Dearomative Intramolecular (4+3) Cycloadditions of Arenes with Epoxy and Aziridinyl Enolsilanes
Authors: Ling Jesse , Lam Sarah , Low Kam‐Hung , Chiu Pauline 
Published: May 2017

AbstractAn intramolecular (4+3) cycloaddition of epoxy and aziridinyl enolsilanes with benzene, naphthalene, and anthracene derivatives is reported. Highly functionalized polycyclic alcohols and amines are generated under relatively mild reaction conditions with yields up to 89 %. Optically enriched cycloadducts are obtained from cycloadditions of enantiomerically pure epoxides and aziridines.
Polynitro‐Functionalized Dipyrazolo‐1,3,5‐triazinanes: Energetic Polycyclization toward High Density and Excellent Molecular Stability
Authors: Yin Ping , Zhang Jiaheng , Imler Gregory H. , Parrish Damon A. , Shreeve Jean'ne M. 
Published: May 2017

AbstractA new fused N‐heterocyclic framework, dipyrazolo‐1,3,5‐triazinane, was synthesized and the physiochemical properties of its derivatives were investigated to evaluate the integrated energetic performance. In contrast to 1,3,5‐trinitro‐1,3,5‐triazinane (RDX) featuring a distorted chair confirmation, polynitro‐functionalized dipyrazolo‐1,3,5‐triazinanes have nearly planar backbones, thereby enhancing the density and thermal stability. Among these new energetic tricyclic compounds, 5 a and 12 show favorable crystal densities of 1.937 g cm−3 and 1.990 g cm−3 at 150 K, respectively, which rank highest in triazinane‐based energetic compounds. Additionally, this synthetic approach was carried out to form seven‐membered and eight‐membered rings, giving rise to tetranitro dipyrazolo‐1,3,5‐triazepane (5 b) and tetranitro dipyrazolo‐1,3,5‐triazocane (5 c), respectively.
Privileged Structures Revisited
Authors: Schneider Petra , Schneider Gisbert 
Published: May 2017

AbstractPrivileged structures inspire compound library design in medicinal chemistry. We performed a comprehensive analysis of 1.4 million bioactive compounds, with the aim of assessing the prevalence of certain molecular frameworks. We used the Shannon entropy formalism to quantify the promiscuity of the most frequently observed atom scaffolds across the annotated target families. This analysis revealed an apparent inverse relationship between hydrogen‐bond‐acceptor count of a scaffold and its potential promiscuity. The results further suggest that chemically easily accessible scaffolds can serve as templates for the generation of bespoke compound libraries with differing degrees of multiple target engagement, and heterocyclic, sp3‐rich frameworks are particularly suited for target‐focused library design. The outcome of our study enables us to place some of the many narratives surrounding the concept of privileged structures into a critical context.
Controlling the α/γ‐Reactivity of Vinylogous Ketone Enolates in Organocatalytic Enantioselective Michael Reactions
Authors: Iriarte Igor , Olaizola Olatz , Vera Silvia , Gamboa Iñaki , Oiarbide Mikel , Palomo Claudio 
Published: May 2017

AbstractThe first regio‐, diastereo‐, and enantioselective direct Michael reaction of β,γ‐unsaturated ketones with nitroolefins is enabled by Brønsted base/hydrogen‐bonding bifunctional catalysis. A squaramide‐substituted tertiary amine catalyzes the reaction of a broad range of β,γ‐unsaturated ketones to proceed at the α‐site exclusively, giving rise to adducts with two consecutive tertiary carbon stereocenters in diastereomeric ratios of up to >20:1 and enantioselectivities generally in the 90–98 % ee range.
Direct Zinc(II)‐Catalyzed Enantioconvergent Additions of Terminal Alkynes to α‐Keto Esters
Authors: Zavesky Blane P. , Johnson Jeffrey S. 
Published: May 2017

AbstractThe addition of terminal alkynes to racemic β‐stereogenic α‐keto esters was achieved in high levels of stereoselectivity, affording versatile tertiary propargylic alcohols containing two stereocenters. This environmentally benign enantioconvergent reaction proceeds with perfect atom economy, requires no solvent, and is catalyzed by a non‐toxic zinc salt. The alkyne moiety can be leveraged in downstream transformations including hydrogenation to the corresponding saturated tertiary alcohol, which represents the product of a formal enantioconvergent aliphatic nucleophile addition.
Aromatic‐Imide‐Based Thermally Activated Delayed Fluorescence Materials for Highly Efficient Organic Light‐Emitting Diodes
Authors: Li Meng , Liu Yanwei , Duan Ruihong , Wei Xiaofang , Yi Yuanping , Wang Ying , Chen Chuan‐Feng 
Published: May 2017

AbstractAromatic‐imide‐based thermally activated delayed fluorescence (TADF) materials with a twisted donor–acceptor–donor skeleton were efficiently synthesized and exhibited excellent thermal stability and high photoluminescence quantum yields. The small ΔEST value (<0.1 eV) along with the clear temperature‐dependent delayed component of their transient photoluminescence (PL) spectra demonstrated their excellent TADF properties. Moreover, the performance of organic light‐emitting diodes in which TADF materials AI‐Cz and AI‐TBCz were used as dopants were outstanding, with external quantum efficiencies up to 23.2 and 21.1 %, respectively.
Quaternary ammonium‐functionalized polymers in biodegradable matrices: Physicochemical properties, morphology, and biodegradability
Authors: Belkhir Kedafi , Jegat Corinne , Prochazka Frédéric , Taha Mohamed 
Published: May 2017

ABSTRACTQuaternary ammonium‐functionalized polymers (QAFPs) based on branched structures of poly(lactic acid) (PLA) and polycaprolactone (PCL) were blended with neat matrices of PLA and PCL to improve their processability in the melt phase at 160 °C. Different formulations were prepared by varying the proportions of the components of the blends (0, 10, 20, 50, and 60 wt % of QAFP). The rheological behavior of each component and their blends was studied at 160 °C and dynamic mechanical analyses were carried out. The thermal properties of the matrices were also investigated by thermogravimetric analyses and differential scanning calorimetry; they were found to be affected by the presence of QAFPs within them. All the studied blends had a dispersed morphology, highlighted by scanning electron microscopy. The water contact angle of the blends was studied and showed that the hydrophilicity of the surfaces of the blends increased by increasing their QAFP content. The biodegradability of both the components and the blends was investigated: a decrease of the biodegradation kinetics was observed due to the presence of the quaternary ammonium groups, but the materials remain biodegradable. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45261.