bluuebunny/crossref_metadata_2025 huggingface dataset:
T-cell calcium dynamics visualized in a ratiometric tdTomato-GCaMP6f transgenic reporter mouse
Authors: Dong Tobias X , Othy Shivashankar , Jairaman Amit , Skupsky Jonathan , Zavala Angel , Parker Ian , Dynes Joseph L , Cahalan Michael D
Published: December 2017

Calcium is an essential cellular messenger that regulates numerous functions in living organisms. Here, we describe development and characterization of ‘Salsa6f’, a fusion of GCaMP6f and tdTomato optimized for cell tracking while monitoring cytosolic Ca2+, and a transgenic Ca2+ reporter mouse with Salsa6f targeted to the Rosa26 locus for Cre-dependent expression in specific cell types. The development and function of T cells was unaffected in Cd4-Salsa6f mice. We describe Ca2+ signals reported by Salsa6f during T cell receptor activation in naive T cells, helper Th17 T cells and regulatory T cells, and Ca2+ signals mediated in T cells by an activator of mechanosensitive Piezo1 channels. Transgenic expression of Salsa6f enables ratiometric imaging of Ca2+ signals in complex tissue environments found in vivo. Two-photon imaging of migrating T cells in the steady-state lymph node revealed both cell-wide and localized sub-cellular Ca2+ transients (‘sparkles’) as cells migrate.
SIRT2 and lysine fatty acylation regulate the transforming activity of K-Ras4a
Authors: Jing Hui , Zhang Xiaoyu , Wisner Stephanie A , Chen Xiao , Spiegelman Nicole A , Linder Maurine E , Lin Hening
Published: December 2017

Ras proteins play vital roles in numerous biological processes and Ras mutations are found in many human tumors. Understanding how Ras proteins are regulated is important for elucidating cell signaling pathways and identifying new targets for treating human diseases. Here we report that one of the K-Ras splice variants, K-Ras4a, is subject to lysine fatty acylation, a previously under-studied protein post-translational modification. Sirtuin 2 (SIRT2), one of the mammalian nicotinamide adenine dinucleotide (NAD)-dependent lysine deacylases, catalyzes the removal of fatty acylation from K-Ras4a. We further demonstrate that SIRT2-mediated lysine defatty-acylation promotes endomembrane localization of K-Ras4a, enhances its interaction with A-Raf, and thus promotes cellular transformation. Our study identifies lysine fatty acylation as a previously unknown regulatory mechanism for the Ras family of GTPases that is distinct from cysteine fatty acylation. These findings highlight the biological significance of lysine fatty acylation and sirtuin-catalyzed protein lysine defatty-acylation.
How does obesity lead to insulin resistance?
Authors: Choi Chan Hee J , Cohen Paul
Published: December 2017

Experiments on mice show that an enzyme called DNA methyltransferase 3a is involved in insulin resistance via an epigenetic mechanism.
A Morpho-Syntactic Analysis of Modal Verbs in Iraqi Dialects: A Comparative Study
Authors: Mohammed Abbas Amthal , Kadir Mugair Sarab
Published: December 2017

This study is an attempt to investigate and analyze the linguistic forms of modal verbs in three Iraqi dialects. These modal verbs are "can", "will" and "must” and the dialects under study are Musiliyah that is spoken in Mosul province in the north of Iraq, Baghdadiyah that is spoken in Baghdad city  in the middle of Iraq and Basriyah  that is spoken in the city of Basrah in the south. The study adopts the descriptive and comparative techniques of James' theory (1998) to analyze the data. The present study  aims to investigate and analyze three modal verbs in three Iraqi dialects. It tends to share the same views of Ma'ruf (2011:24) and James (1998:19) who state that nations’ dialects can be fruitful which in turn can enrich their mother tongue, in disagreement with Lakoff (1972:) who argues that dialects may hinder their mother tongue which eventually can be fuzzier than of great help. The findings of the present study  reveal that, in a way or another, speakers of IDs can use different kinds of clauses to convey the general and  predicative meaning simultaneously. Dialects can help speakers of IDs reinforce their specificities and preferences, i.e., dialects strengthen their ability to create new words, which at long last, enrich their mother tongue. The analysis of the present study proves the usability of Ma'ruf’s (2011) and James’ (1998) standing regarding the dialects. Contrarily, the analysis also shows that Lakoff's views (1972) are not , to an extent, objective, i.e., her views are relative.
Grice’s Conversational Implicature: A Pragmatics Analysis of Selected Poems of Audre Lorde
Authors: Igwedibia Adaoma
Published: December 2017

A number of works have been done by scholars on the study and interpretation of Audre Lorde’s poetry, especially through the lens of literary and critical analysis. However, Lorde’s poems have not been analyzed pragmatically. A lot may have been written about Lorde’s poetry, but there is absolutely no evidence of a pragmatics study of her work. Lorde is the author of many poems that have been studied in various theoretical dimensions, but none have been done with reference to their pragmatics implications. The problem which this research recognizes, therefore, is that Lorde’s poems, especially the ones under the present study, have not been studied and interpreted using Grice’s theory of Conversational Implicature (Cooperative Principle) which is comprised the four maxims: the maxims of Quantity, Quality, Manner and Relation. This study seeks to discover the extent to which these maxims  could be applied to the reading of the selected poems of Lorde. It also seeks to ascertain the degree to which Lorde’s selected poems violate or adhere to these maxims. The study has found that Audre Lorde in some of her poems, violates the maxims as well as adheres to them both in the same breath.
The Effect of Two Pre- task Activities: Pre- taught Vocabulary and Brainstorming on Intermediate EFL Learners’ Reading Comprehension
Authors: Khalili Sabet Masoud , Tahriri Abdorreza , Shirkoohi Somayeh Rostami
Published: December 2017

The primary purpose of the present study was to investigate the effectiveness of two pre- task activities of reading: pre- taught vocabulary and brainstorming in EFL learners’ reading comprehending.  To this end, three intact classes in a private English Institute in Tehran, were selected from a population of 60 English learners.  Based on their scores on Oxford Placement Test (OPT), the students were randomly assigned into two experimental groups and one control group and a pre-test was run at the beginning of the course. At outset of the course a pre- test was run among three groups.  The researcher instructed the experimental groups in 16 weeks, one session a week and lasting 40 minutes in each session. The first experimental group benefited from pre- taught vocabulary, while the second experimental group benefited from brainstorming as a pre- task and the third group did not receive any pre- task activities in the reading class. At the end of the course, a post- test with the same items of the pre- test was run to determine the improvement of EFL intermediate students’ reading comprehension changes and an attitude questionnaire was planned to determine the learners’ attitudes toward the pre- task activities.    The results of paired sample t- test indicated that the use of pre- taught vocabulary and also brainstorming enhanced the scores of  the first experimental and second experimental groups’  post- tests ; moreover, ANOVA results revealed a significant increase in reading comprehension scores  of the first and the second  experimental groups’ post- tests compared to the control group’ post-test scores.  The results of attitude questionnaire demonstrated the pupils’ positive attitudes toward the use of pre- task activities.
The Effect of Problem Solving Task on Critical Reading of Intermediate EFL Learners in Iranian Context
Authors: Khalili Sabet Masoud , Madavi Zafarghandi Amir , Norouz Karkaraq Arezoo
Published: December 2017

The attempt in this study is to investigate the effect of teaching critical thinking through problem solving on  reading comprehension performance of EFL intermediate learners. In so doing, forty including twenty male and twenty female intermediate students studying English in an institute in Ardabil, Iran, were selected based on their scores on Preliminary English Test and assigned into control and experimental groups. Afterwards, the sample TOEFL reading comprehension pre-test was administered to both of these groups to ensure homogeneity. The learners in experimental group were taught through problem solving instruction and the learners in control group were taught through traditional method of instructing reading comprehension. After ten sessions of instruction, the same sample TOEFL reading comprehension as post-test was given to the learners to measure the possible differences between pre-test and post-test. The finding revealed teaching problem solving had statistically significant effect on EFL learners reading comprehension performance. Conclusion can be drawn to confirm that teaching critical thinking through problem solving bring better understanding of the text.
A Fluid Pulse on the Hikurangi Subduction Margin: Evidence From a Heat Flux Transect Across the Upper Limit of Gas Hydrate Stability
Authors: Pecher I. A. , Villinger H. , Kaul N. , Crutchley G. J. , Mountjoy J. J. , Huhn K. , Kukowski N. , Henrys S. A. , Rose P. S. , Coffin R. B.
Published: December 2017

A transect of seafloor heat probe measurements on the Hikurangi Margin shows a significant increase of thermal gradients upslope of the updip limit of gas hydrate stability at the seafloor. We interpret these anomalously high thermal gradients as evidence for a fluid pulse leading to advective heat flux, while endothermic cooling from gas hydrate dissociation depresses temperatures in the hydrate stability field. Previous studies predict a seamount on the subducting Pacific Plate to cause significant overpressure beneath our study area, which may be the source of the fluid pulse. Double‐bottom simulating reflections are present in our study area and likely caused by uplift based on gas hydrate phase boundary considerations, although we cannot exclude a thermogenic origin. We suggest that uplift may be associated with the leading edge of the subducting seamount. Our results provide further evidence for the transient nature of fluid expulsion in subduction zones.
Spatial and Temporal Evolution of Earthquake Dynamics: Case Study of the Mw 8.3 Illapel Earthquake, Chile
Authors: Yin Jiuxun , Denolle Marine A. , Yao Huajian
Published: December 2017

We develop a methodology that combines compressive sensing backprojection (CS‐BP) and source spectral analysis of teleseismic P waves to provide metrics relevant to earthquake dynamics of large events. We improve the CS‐BP method by an autoadaptive source grid refinement as well as a reference source adjustment technique to gain better spatial and temporal resolution of the locations of the radiated bursts. We also use a two‐step source spectral analysis based on (i) simple theoretical Green's functions that include depth phases and water reverberations and on (ii) empirical P wave Green's functions. Furthermore, we propose a source spectrogram methodology that provides the temporal evolution of dynamic parameters such as radiated energy and falloff rates. Bridging backprojection and spectrogram analysis provides a spatial and temporal evolution of these dynamic source parameters. We apply our technique to the recent 2015 Mw 8.3 megathrust Illapel earthquake (Chile). The results from both techniques are consistent and reveal a depth‐varying seismic radiation that is also found in other megathrust earthquakes. The low‐frequency content of the seismic radiation is located in the shallow part of the megathrust, propagating unilaterally from the hypocenter toward the trench while most of the high‐frequency content comes from the downdip part of the fault. Interpretation of multiple rupture stages in the radiation is also supported by the temporal variations of radiated energy and falloff rates. Finally, we discuss the possible mechanisms, either from prestress, fault geometry, and/or frictional properties to explain our observables. Our methodology is an attempt to bridge kinematic observations with earthquake dynamics.
Investigating Compaction by Intergranular Pressure Solution Using the Discrete Element Method
Authors: van den Ende M. P. A. , Marketos G. , Niemeijer A. R. , Spiers C. J.
Published: December 2017

Intergranular pressure solution creep is an important deformation mechanism in the Earth's crust. The phenomenon has been frequently studied and several analytical models have been proposed that describe its constitutive behavior. These models require assumptions regarding the geometry of the aggregate and the grain size distribution in order to solve for the contact stresses and often neglect shear tractions. Furthermore, analytical models tend to overestimate experimental compaction rates at low porosities, an observation for which the underlying mechanisms remain to be elucidated. Here we present a conceptually simple, 3‐D discrete element method (DEM) approach for simulating intergranular pressure solution creep that explicitly models individual grains, relaxing many of the assumptions that are required by analytical models. The DEM model is validated against experiments by direct comparison of macroscopic sample compaction rates. Furthermore, the sensitivity of the overall DEM compaction rate to the grain size and applied stress is tested. The effects of the interparticle friction and of a distributed grain size on macroscopic strain rates are subsequently investigated. Overall, we find that the DEM model is capable of reproducing realistic compaction behavior, and that the strain rates produced by the model are in good agreement with uniaxial compaction experiments. Characteristic features, such as the dependence of the strain rate on grain size and applied stress, as predicted by analytical models, are also observed in the simulations. DEM results show that interparticle friction and a distributed grain size affect the compaction rates by less than half an order of magnitude.
Holocene Event Record of Aysén Fjord (Chilean Patagonia): An Interplay of Volcanic Eruptions and Crustal and Megathrust Earthquakes
Authors: Wils Katleen , Van Daele Maarten , Lastras Galderic , Kissel Catherine , Lamy Frank , Siani Giuseppe
Published: December 2017

In the first months of 2007, the Aysén region in southern Chile was affected by a crustal seismic swarm. Its largest earthquake (Mw 6.2) occurred in April and had its epicenter in Aysén Fjord. Seismic intensities became so high that hundreds of onshore mass movements were triggered, several of which entered into the fjord, resulting in mass transport deposits (MTDs) preserved at the fjord bottom. Here we present a Holocene record of paleo‐earthquakes in the previously unstudied Patagonian fjordland based on MTD stratigraphy. High‐resolution seismic data retrieved using two different seismic systems (sparker and TOPAS) reveal multiple older MTDs on different stratigraphic levels. Correlation of the seismic stratigraphy with sedimentological data obtained from a long Calypso core (MD07‐3117) allows conclusion on the seismic origin of these deposits. Additionally, radiocarbon dating permits constructing an age model, validated by tephrochronology, providing an age for the different MTD levels. We thus present a highly detailed paleoseismological history of the Aysén region, including at least six major Holocene earthquakes, one of which is likely related to a known megathrust earthquake. Other earthquakes are related to activity of the Liquiñe‐Ofqui Fault Zone (LOFZ), forming the main source of seismic hazard in the area. We can infer a general average recurrence time for LOFZ earthquakes of ~2,100 years in the vicinity of Aysén Fjord with clustered events during the early and late Holocene. Finally, we argue that cascading events (causal link between volcanic and seismic events) may be a frequent phenomenon along the LOFZ.
Inelastic Compaction in High‐Porosity Limestone Monitored Using Acoustic Emissions
Authors: Baud Patrick , Schubnel Alexandre , Heap Michael , Rolland Alexandra
Published: December 2017

We performed a systematic investigation of mechanical compaction and strain localization in Saint‐Maximin limestone, a quartz‐rich, high‐porosity (37%) limestone from France. Our new data show that the presence of a significant proportion of secondary mineral (i.e., quartz) did not impact the mechanical strength of the limestone in both the brittle faulting and cataclastic flow regimes, but that the presence of water exerted a significant weakening effect. In contrast to previously published studies on deformation in limestones, inelastic compaction in Saint‐Maximin limestone was accompanied by abundant acoustic emission (AE) activity. The location of AE hypocenters during triaxial experiments revealed the presence of compaction localization. Two failure modes were identified in agreement with microstructural analysis and X‐ray computed tomography imaging: compactive shear bands developed at low confinement and complex diffuse compaction bands formed at higher confinement. Microstructural observations on deformed samples suggest that the recorded AE activity associated with inelastic compaction, unusual for a porous limestone, could have been due to microcracking at the quartz grain interfaces. Similar to published data on high‐porosity macroporous limestones, the crushing of calcite grains was the dominant micromechanism of inelastic compaction in Saint‐Maximin limestone. New P wave velocity data show that the effect of microcracking was dominant near the yield point and resulted in a decrease in P wave velocity, while porosity reduction resulted in a significant increase in P wave velocity beyond a few percent of plastic volumetric strain. These new data highlight the complex interplay between mineralogy, rock microstructure, and strain localization in porous rocks.
A New Southern North Atlantic Isochron Map: Insights Into the Drift of the Iberian Plate Since the Late Cretaceous
Authors: Macchiavelli Chiara , Vergés Jaume , Schettino Antonio , Fernàndez Manel , Turco Eugenio , Casciello Emilio , Torne Montserrat , Pierantoni Pietro Paolo , Tunini Lavinia
Published: December 2017

This paper presents a new southern North Atlantic plate model from Late Cretaceous to present, with the aim of constraining the kinematics of the Iberian plate during the last 83.5 Myr. This model is presented along with a detailed isochron map generated through the analysis of 3 aeromagnetic tracks and ~400 ship tracks from the National Centers for Environmental Information database. We present a new technique to obtain well‐constrained estimates of the Iberia‐North America plate motions from magnetic anomalies, overcoming the scarcity of large‐offset fracture zones and transform faults. We build an integrated kinematic model for NW Africa, Morocco, Iberia, Europe, and North America, which shows that the deformation is partitioned between Pyrenees and Betic‐Rif orogenic domain during the Late Cretaceous‐Oligocene time interval. In the Eastern Betics domain, the calculated amount of NW Africa‐Iberia convergence is ~80 km between 83.5 and 34 Ma, followed by ~150 km since the Oligocene. The motion of Iberia relative to Europe in the Central Pyrenees is characterized by overall NE directed transpressional motion during the Campanian and the Paleocene, followed by NW directed transpressional movement until the Lutetian and overall NNW directed convergence from Bartonian to Chattian. This motion occurs along the axis of the Bay of Biscay from the Santonian–Campanian boundary to the middle Priabonian, subsequently jumping to King's Trough at Anomaly 17 (36.62 Ma).
Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
Authors: Schlömer Antje , Geissler Wolfram H. , Jokat Wilfried , Jegen Marion
Published: December 2017

Earthquake locations along the southern Mid‐Atlantic Ridge have large uncertainties due to the sparse distribution of permanent seismological stations in and around the South Atlantic Ocean. Most of the earthquakes are associated with plate tectonic processes related to the formation of new oceanic lithosphere, as they are located close to the ridge axis or in the immediate vicinity of transform faults. A local seismological network of ocean‐bottom seismometers and land stations on and around the archipelago of Tristan da Cunha allowed for the first time a local earthquake survey for 1 year. We relate intraplate seismicity within the African oceanic plate segment north of the island partly to extensional stresses induced by a bordering large transform fault and to the existence of the Tristan mantle plume. The temporal propagation of earthquakes within the segment reflects the prevailing stress field. The strong extensional stresses in addition with the plume weaken the lithosphere and might hint at an incipient ridge jump. An apparently aseismic zone coincides with the proposed location of the Tristan conduit in the upper mantle southwest of the islands. The margins of this zone describe the transition between the ductile and the surrounding brittle regime. Moreover, we observe seismicity close to the islands of Tristan da Cunha and nearby seamounts, which we relate to ongoing tectono‐magmatic activity.
Non‐Redfieldian Dynamics Explain Seasonal pCO2Drawdown in the Gulf of Bothnia
Authors: Fransner Filippa , Gustafsson Erik , Tedesco Letizia , Vichi Marcello , Hordoir Robinson , Roquet Fabien , Spilling Kristian , Kuznetsov Ivan , Eilola Kari , Mörth Carl‐Magnus , Humborg Christoph , Nycander Jonas
Published: December 2017

High inputs of nutrients and organic matter make coastal seas places of intense air‐sea CO2exchange. Due to their complexity, the role of coastal seas in the global air‐sea CO2exchange is, however, still uncertain. Here, we investigate the role of phytoplankton stoichiometric flexibility and extracellular DOC production for the seasonal nutrient and CO2partial pressure (pCO2) dynamics in the Gulf of Bothnia, Northern Baltic Sea. A 3‐D ocean biogeochemical‐physical model with variable phytoplankton stoichiometry is for the first time implemented in the area and validated against observations. By simulating non‐Redfieldian internal phytoplankton stoichiometry, and a relatively large production of extracellular dissolved organic carbon (DOC), the model adequately reproduces observed seasonal cycles in macronutrients and pCO2. The uptake of atmospheric CO2is underestimated by 50% if instead using the Redfield ratio to determine the carbon assimilation, as in other Baltic Sea models currently in use. The model further suggests, based on the observed drawdown of pCO2, that observational estimates of organic carbon production in the Gulf of Bothnia, derived with themethod, may be heavily underestimated. We conclude that stoichiometric variability and uncoupling of carbon and nutrient assimilation have to be considered in order to better understand the carbon cycle in coastal seas.
Variability of Phytoplankton Size Structure in Response to Changes in Coastal Upwelling Intensity in the Southwestern East Sea
Authors: Shin Jung‐Wook , Park Jinku , Choi Jang‐Geun , Jo Young‐Heon , Kang Jae Joong , Joo HuiTae , Lee Sang Heon
Published: December 2017

The aim of this study was to examine the size structure of phytoplankton under varying coastal upwelling intensities and to determine the resulting primary productivity in the southwestern East Sea. Samples of phytoplankton assemblages were collected on five occasions from the Hupo Bank, off the east coast of Korea, during 2012–2013. Because two major surface currents have a large effect on water mass transport in this region, we first performed a Backward Particle Tracking Experiment (BPTE) to determine the coastal sea from which the collected samples originated according to advection time of BPTE particles, following which we used upwelling age (UA) to determine the intensity of coastal upwelling in the region of origin for each sample. Only samples that were affected by coastal upwelling in the region of origin were included in subsequent analyses. We found that as UA increased, there was a decreasing trend in the concentration of picophytoplankton, and increasing trends in the concentration of nanophytoplankton and microphytoplankton. We also examined the relationship between the size structure of phytoplankton and primary productivity in the Ulleung Basin (UB), which has experienced significant variation over the past decade. We found that primary productivity in UB was closely related to the strength of the southerly wind, which is the most important mechanism for coastal upwelling in the southwestern East Sea. Thus, the size structure of phytoplankton is determined by the intensity of coastal upwelling, which is regulated by the southerly wind, and makes an important contribution to primary productivity.
Excitation Location and Seasonal Variation of Transoceanic Infragravity Waves Observed at an Absolute Pressure Gauge Array
Authors: Tonegawa T. , Fukao Y. , Shiobara H. , Sugioka H. , Ito A. , Yamashita M.
Published: December 2017

An array of 10 absolute pressure gauges (APGs) deployed in deep water 50 km east of Aogashima, an island in southern Japan, observed several isolated signals in the infragravity wave (IGW) frequency band (0.002–0.03 Hz) during boreal summer, whereas relatively high IGW energy persisted during boreal winter. The isolated IGW shows dispersion with a delay time of 4–5 days as a function of frequency. Here we estimate the excitation locations of IGWs for the two seasons with estimated incoming direction of IGW, calculation of transoceanic IGW trajectories and propagation times, and spatiotemporal variations of significant wave heights from WAVEWATCH III. In boreal summer, the isolated IGWs are primarily caused by IGW energies excited at the shoreline of South America, based on the following three observations: IGWs observed at the array originated from the east: the easterly ray path from the array reaches South America: and an event‐like IGWs were observed at the array when a storm approaches eastward to the shoreline of South America, in which the observed delay time of 4–5 days was also supported by the frequency‐dependent calculation of IGW propagation times. In boreal winter, the incessant IGWs consist of transoceanic IGW energies leaked from the shoreline, primarily from North America, and secondly from South America and the western Aleutian Islands.
Mitigating Satellite‐Based Fire Sampling Limitations in Deriving Biomass Burning Emission Rates: Application to WRF‐Chem Model Over the Northern sub‐Saharan African Region
Authors: Wang Jun , Yue Yun , Wang Yi , Ichoku Charles , Ellison Luke , Zeng Jing
Published: December 2017

Largely used in several independent estimates of fire emissions, fire products based on MODIS sensors aboard the Terra and Aqua polar‐orbiting satellites have a number of inherent limitations, including (a) inability to detect fires below clouds, (b) significant decrease of detection sensitivity at the edge of scan where pixel sizes are much larger than at nadir, and (c) gaps between adjacent swaths in tropical regions. To remedy these limitations, an empirical method is developed here and applied to correct fire emission estimates based on MODIS pixel level fire radiative power measurements and emission coefficients from the Fire Energetics and Emissions Research (FEER) biomass burning emission inventory. The analysis was performed for January 2010 over the northern sub‐Saharan African region. Simulations from WRF‐Chem model using original and adjusted emissions are compared with the aerosol optical depth (AOD) products from MODIS and AERONET as well as aerosol vertical profile from CALIOP data. The comparison confirmed an 30–50% improvement in the model simulation performance (in terms of correlation, bias, and spatial pattern of AOD with respect to observations) by the adjusted emissions that not only increases the original emission amount by a factor of two but also results in the spatially continuous estimates of instantaneous fire emissions at daily time scales. Such improvement cannot be achieved by simply scaling the original emission across the study domain. Even with this improvement, a factor of two underestimations still exists in the modeled AOD, which is within the current global fire emissions uncertainty envelope.
Thermochronometry Across the Austroalpine‐Pennine Boundary, Central Alps, Switzerland: Orogen‐Perpendicular Normal Fault Slip on a Major “Overthrust” and Its Implications for Orogenesis
Authors: Price Jason B. , Wernicke Brian P. , Cosca Michael A. , Farley Kenneth A.
Published: December 2017

Fifty‐one new and 309 published thermochronometric ages (nine systems with closure temperatures ranging from ~450 to 70°C) from the Graubünden region of the Central Alps demonstrate that a pronounced thermal mismatch between the Austroalpine allochthon (Alpine “orogenic lid”) and the Pennine zone persisted until at least 29 Ma and, allowably, until circa 18 Ma. The observed mismatch supports previous suggestions that the famous “overthrust” between the Austroalpine allochthon and the Pennine zone, historically regarded as primarily an Eocene top‐north thrust fault, is in fact primarily an Oligocene‐Miocene normal fault that has a minimum of 60 km of displacement with top‐south or top‐southeast sense of shear. Two hallmarks of Alpine geology, deposition of the foredeep Molasse and emplacement of the Helvetic nappes, appear to be coeval, peripheral manifestations of crustal thickening via the interposition of the Pennine zone as a northward intruding wedge between the Austroalpine “lid” and the European cratonic margin, with the Helvetic system (European margin) acting as the “floor” of the wedge. We presume the Penninic wedge is driven by the buoyant rise of subducted crust no longer able to remain attached to the descending slab. If so, emplacement of the Pennine wedge could have occurred mainly after Adria was juxtaposed against cratonic Europe.
Adaptation to Sea Level Rise: A Multidisciplinary Analysis for Ho Chi Minh City, Vietnam
Authors: Scussolini Paolo , Tran Thi Van Thu , Koks Elco , Diaz‐Loaiza Andres , Ho Phi Long , Lasage Ralph
Published: December 2017

One of the most critical impacts of sea level rise is that flooding suffered by ever larger settlements in tropical deltas will increase. Here we look at Ho Chi Minh City, Vietnam, and quantify the threats that coastal floods pose to safety and to the economy. For this, we produce flood maps through hydrodynamic modeling and, by combining these with data sets of exposure and vulnerability, we estimate two indicators of risk: the damage to assets and the number of potential casualties. We simulate current and future (2050 and 2100) flood risk using IPCC scenarios of sea level rise and socioeconomic change. We find that annual damage may grow by more than 1 order of magnitude, and potential casualties may grow 5–20‐fold until the end of the century, in the absence of adaptation. Impacts depend strongly on the climate and socioeconomic scenarios considered. Next, we simulate the implementation of adaptation measures and calculate their effectiveness in reducing impacts. We find that a ring dike would protect the inner city but increase risk in more rural districts, whereas elevating areas at risk and dryproofing buildings will reduce impacts to the city as a whole. Most measures perform well from an economic standpoint. Combinations of measures seem to be the optimal solution and may address potential equity conflicts. Based on our results, we design possible adaptation pathways for Ho Chi Minh City for the coming decades; these can inform policy‐making and strategic thinking.
Relationship Between Institutional Standardized Letter of Evaluation Global Assessment Ranking Practices, Interviewing Practices, and Medical Student Outcomes
Authors: Pelletier‐Bui Alexis , Van Meter Michael , Pasirstein Michael , Jones Christopher , Rimple Diane
Published: December 2017

Background

Emergency medicine (EM) program directors rely largely on the standardized letter of evaluation (SLOE) to help determine which applicants to interview in the face of an increasing number of applications. To further characterize the SLOE's role in the EM application process, particularly the global assessment (GA) ranking and its effect on interviewing practices and medical student outcomes, the leaders of EM programs were surveyed regarding their experiences in both generating and utilizing the SLOE.

Methods

Individuals on the Council of Emergency Medicine Residency Directors (CORD) and Clerkship Directors in Emergency Medicine (CDEM) Academy listservs were anonymously surveyed from March 21–30, 2015, with 18 questions in multiple‐choice and fill‐in‐the‐blank formats.

Results

There were 99 respondents. Only 39 respondents (39%) reported adhering strictly to SLOE guidelines by evenly placing their students into thirds (top, middle, lower) on the SLOE GA. Most respondents interviewed individuals ranked in the lower third. Programs adhering strictly to ranking guidelines were more likely to interview students in the lower third than those adhering loosely or not at all. There was no relationship between a program's self‐reported adherence to the SLOE ranking guidelines and the number of unmatched students in EM during the 2014 and 2015 academic years.

Conclusion

Many SLOE writers do not strictly adhere to CORD's SLOE writing guidelines when using the GA ranking, due to the fear of adversely impacting an applicant's ability to successfully match into EM. This calls into question the validity of the SLOE as it is currently used. However, this study suggests that adhering to recommended SLOE ranking guidelines is unlikely to substantially increase the risk that students will fail to match. If more evaluators were to adhere to the guidelines, the SLOE could become the valid evaluation instrument that graduate medical education has long been pursuing.
Iron‐Catalyzed Aminative Cyclization/Intermolecular Homolytic Aromatic Substitution Using Oxime Esters and Simple Arenes
Authors: Shimbayashi Takuya , Okamoto Kazuhiro , Ohe Kouichi
Published: December 2017

Intermolecular C−H alkylation of simple arenes in the presence of an iron catalyst has been achieved in a cascade manner with an aminative cyclization triggered by N−O bond cleavage of an alkene‐tethered oxime ester. Various arenes, including electron‐rich and electron‐poor arenes, and heteroarenes can be employed in the reaction system. Regioselectivity and radical trapping experiments support the involvement of alkyl radical species, which undergo a homolytic aromatic substitution (HAS) to afford the arylation products.
Planung und Realisierung einer innerstädtischen tiefen Trogbaugrube bei komplexen Randbedingungen
Authors: Stahlhut Olaf , Borchert Kurt.‐M. , Voigt Robert E.
Published: December 2017

Beim BV Alter Wall wird die Erschaffung hochwertiger Büro‐ und Einzelhandelsflächen im Herzen der Hamburger Innenstadt realisiert. In Zusammenarbeit mit dem BID Nikolai‐Quartier (Business‐Improvement‐District) wird der Alte Wall in einen hochwertigen innerstädtischen Boulevard umgestaltet. Dazu werden in unmittelbarer Nähe des Rathauses in Hamburg vorhandene Gebäude bis auf die straßenseitige Fassade rückgebaut und eine Tiefgarage mit fünf Untergeschossen errichtet. In diesem Bereich liegen sehr inhomogene geologische Verhältnisse, bestehend aus Auffüllungen, organischen Weichschichten sowie Wechsellagerungen aus Sanden, Geschiebemergeln und Tonen, vor. Auf Grundlage der Ergebnisse der im Vorfeld außerhalb des Baufelds durchgeführten Baugrunduntersuchungen wurde die Baugrube als Trogbaugrube geplant. Als Baugrubenumschließung wurde eine Schlitzwand mit Tiefen von 43–50 m bis in die erkundeten natürlichen Dichtschichten ausgeführt. Die Baugrube wurde zweifach ausgesteift und zusätzlich zur Sicherung des ca. 7 m hohen Geländesprungs von der Seite Alter Wall zum Fleet mittels Ankern einseitig rückverankert. Bevor die Abbrucharbeiten des Gebäudes begonnen wurden, war die Durchführung von Baugrunduntersuchungen direkt im Baufeld nicht möglich. Die nach Abbruch durchgeführten Baugrunduntersuchungen im Baufeld haben ergeben, dass in einem Bereich der Baugrube eine vermutete tiefe glaziale Sandrinne vorhanden ist, sodass die Schlitzwand nicht in der natürlichen Dichtschicht abgesetzt werden konnte, da diese erst in einer Tiefe von ca. 70 m unter Gelände ansteht. Als Abdichtungsmaßnahme wurde ein vertikaler Dichtschleier mit Weichgel, der von Unterkante der Schlitzwand bis in die natürliche Dichtschicht reicht, realisiert. Aufgrund während der Herstellung der Baugrubenumschließung neu gewonnener Erkenntnisse musste die Planung aktualisiert und unmittelbar auf der Baustelle umgesetzt werden. Die Entwicklung und die dynamische Fortschreibung der Baugrubenplanung, die Ergebnisse der Verformungs‐ und Grundwasserstandsmessungen, die Sicherstellung der verträglichen Verformung der historischen Bebauung sowie der abgestützten Fassade und der Funktionsfähigkeit der Holzpfahlgründung des Hamburger Rathauses werden erläutert.
A low‐cost multimodal head‐mounted display system for neuroendoscopic surgery
Authors: Xu Xinghua , Zheng Yi , Yao Shujing , Sun Guochen , Xu Bainan , Chen Xiaolei
Published: December 2017

Background

With rapid advances in technology, wearable devices as head‐mounted display (HMD) have been adopted for various uses in medical science, ranging from simply aiding in fitness to assisting surgery. We aimed to investigate the feasibility and practicability of a low‐cost multimodal HMD system in neuroendoscopic surgery.

Methods

A multimodal HMD system, mainly consisted of a HMD with two built‐in displays, an action camera, and a laptop computer displaying reconstructed medical images, was developed to assist neuroendoscopic surgery. With this intensively integrated system, the neurosurgeon could freely switch between endoscopic image, three‐dimensional (3D) reconstructed virtual endoscopy images, and surrounding environment images. Using a leap motion controller, the neurosurgeon could adjust or rotate the 3D virtual endoscopic images at a distance to better understand the positional relation between lesions and normal tissues at will.

Results

A total of 21 consecutive patients with ventricular system diseases underwent neuroendoscopic surgery with the aid of this system. All operations were accomplished successfully, and no system‐related complications occurred. The HMD was comfortable to wear and easy to operate. Screen resolution of the HMD was high enough for the neurosurgeon to operate carefully. With the system, the neurosurgeon might get a better comprehension on lesions by freely switching among images of different modalities. The system had a steep learning curve, which meant a quick increment of skill with it. Compared with commercially available surgical assistant instruments, this system was relatively low‐cost.

Conclusions

The multimodal HMD system is feasible, practical, helpful, and relatively cost efficient in neuroendoscopic surgery.
The Dynamic Equilibrium of Hexakis(pentafluoroethyl)distannane Adducts [XSn(C2F5)3{Sn(C2F5)3}]− (X=Cl, Br, I, Sn(C2F5)3)
Authors: Wiesemann Markus , Klösener Johannes , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold
Published: December 2017

The tin–tin bond cleavage of hexaorganodistannanes by nucleophiles is a long‐known reaction and widely used for stannate formation or stannyl group transfer. Herein, we detail our experiments to provide analytical evidence for the existence of the reasonably stable anionic complexes [XSn(C2F5)3{Sn(C2F5)3}]− (X=Cl, Br, I, Sn(C2F5)3) derived from hexakis(pentafluoroethyl)distannane. NMR investigations at low temperature lend further mechanistic insights. Thus, by detection of the imposing ion [Sn(C2F5)3{Sn(C2F5)3}2]−, one can surmise that the chemistry of Sn2(C2F5)6 has more in common with the isolobal iodine than with classical distannanes.
Pharmacologic Targeting of Red Blood Cells to Improve Tissue Oxygenation
Authors: Reynolds James D. , Jenkins Trevor , Matto Faisal , Nazemian Ryan , Farhan Obada , Morris Nathan , Longphre John M. , Hess Douglas T. , Moon Richard E. , Piantadosi Claude A. , Stamler Jonathan S.
Published: December 2017

Disruption of microvascular blood flow is a common cause of tissue hypoxia in disease, yet no therapies are available that directly target the microvasculature to improve tissue oxygenation. Red blood cells (RBCs) autoregulate blood flow through S‐nitroso‐hemoglobin (SNO‐Hb)‐mediated export of nitric oxide (NO) bioactivity. We therefore tested the idea that pharmacological enhancement of RBCs using the S‐nitrosylating agent ethyl nitrite (ENO) may provide a novel approach to improve tissue oxygenation. Serial ENO dosing was carried out in sheep (1–400 ppm) and humans (1–100 ppm) at normoxia and at reduced fraction of inspired oxygen (FiO2). ENO increased RBC SNO‐Hb levels, corrected hypoxia‐induced deficits in tissue oxygenation, and improved measures of oxygen utilization in both species. No adverse effects or safety concerns were identified. Inasmuch as impaired oxygenation is a major cause of morbidity and mortality, ENO may have widespread therapeutic utility, providing a first‐in‐class agent targeting the microvasculature.
Single‐Electrode, Nylon‐Fiber‐Enhanced Polytetrafluoroethylene Electret Film with Hollow Cylinder Structure for Mechanical Energy Harvesting
Authors: Zhu Jianxiong , Ma Feng , Zhu Hua
Published: December 2017

A single‐electrode nylon fiber‐incorporated polytetrafluoroethylene (PTFE) electret flexible film with hollow cylinder structure is developed for enhanced mechanical energy harvesting. The power is generated by the nylon fiber/PTFE electret film via bending deformations that result in charges transferring between the conductive carbon black silicone rubber (CBS) electrode and ground. The results demonstrate that the nylon fiber/PTFE electret film results in enhanced open‐circuit voltage, Voc, (about 0.45 times more) compared to a pure PTFE based on the hollow cylinder structure. With the step‐increased distance of travelling for the reported hollow cylinder structure device, more power is generated by this mechanical‐electrical energy conversion because of a greater deformation compression onto the nylon fiber/PTFE electret film. The peak of the generated short‐circuit current, ISC, and Voc based on the nylon fiber/PTFE electret film with 1 m s−2 are up to 0.35 μA and 72 V, respectively. It is also possible to light an 8 light‐emitting diode (LED) setup by finger tapping, demonstrating the good mechanical energy conversion performance of the nylon fiber/PTFE electret film. Moreover, a quick voltage response of the nylon fiber/PTFE electret film is demonstrated in several different ultrasonic environments (such as 70 kHz and 30 kHz).
3D modelling of brittle fracture using a joint all‐atom and phase‐field approach
Authors: Padilla C. A. Hernandez , Patil S. P. , Heider Y. , Markert B.
Published: December 2017

The following research contribution addresses the topic of fracture in highly brittle materials considering a combined computational approach, which includes physically‐motivated molecular dynamics (MD) simulations and multi‐dimensional phase‐field modelling (PFM). This novel approach provides an efficient and accurate insight into multi‐scale fracture modelling. In particular, MD simulations are performed to predict crack propagation on the nano‐scale, which helps to determine material and other model parameters required for the PFM continuum approach. In this connection, this contribution introduces and discusses a 3D PFM of mode‐I fracture using the parameters that are based on the comparison between 2D PFM solutions and MD simulations, introduced in previous works of the authors [1].
Micro‐macro modelling of steel solidification: A continuum mechanical, bi‐phasic, two‐scale model including thermal driven phase transition
Authors: Moj Lukas , Foppe Manuel , Deike Rüdiger , Ricken Tim
Published: December 2017

This paper addresses a continuum‐mechanical, bi‐phasic, two‐scale numerical model for casting and processing of metallic alloys. The solid and liquid physical states, which represents the solid and molten alloy, are formulated in the framework of the theory of porous media (TPM) including thermal coupling, finite plasticity superimposed by a secondary power creep law and visco‐elasticity associated by Darcy's permeability for the solid and the liquid phase, respectively. In view of phase transition during solidification, a two‐scale approach considering the phase‐field on the micro‐scale is proposed, where a double‐well potential with two local minima for completely solid and liquid physical states is utilized. The finite element method based on the standard Gallerkin element formulation and the finite difference method was employed for the macro‐scale and the micro‐scale, respectively. Finally, the performance of the discussed model is demonstrated by the recalculation and validation of a solidification experiment.
Bone Mineral Density and Its Serial Changes Are Associated With PTH Levels in Pseudohypoparathyroidism Type 1B Patients
Authors: Chu Xueying , Zhu Yan , Wang Ou , Nie Min , Quan Tingting , Xue Yu , Wang Wenbo , Jiang Yan , Li Mei , Xia Weibo , Xing Xiaoping
Published: December 2017

Bone responsiveness to serum parathyroid hormone (PTH) in pseudohypoparathyroidism 1B (PHP1B) is controversial. Forty-eight PHP1B patients diagnosed by molecular analysis were recruited from 2000 to 2016 from the Peking Union Medical College Hospital. Fifty-five sex-matched nonsurgical hypoparathyroidism (NS-HP) patients were selected and included for comparison. Basic information, laboratory test, and dual-energy X-ray absorptiometry (DXA) results were collected. Linear regression was performed to identify independent predictors of lumbar spine (LS), femoral neck (FN), and total hip (TH) bone mineral density (BMD) Z-scores in PHP1B patients. BMD and related markers were compared between PHP and NS-HP patients. Longitudinal observation of 10 PHP1B patients was performed. The BMD Z-score for the LS (1.14 ± 1.41) was higher than that for the FN (–0.20 ± 1.00, p < 0.001) and the TH (0.03 ± 1.06, p < 0.001) in PHP1B patients. Despite lower serum calcium levels in untreated patients (1.72 mmol/L in untreated patients versus 2.14 mmol/L in treated patients, p = 0.024), the PTH levels as well as BMD Z-scores were comparable between treated and untreated patients at baseline. PTH was a negative predictor for LS-BMD Z-score (B = –0.004, p = 0.028) for sporadic PHP1B patients, and a similar result was obtained for all the PHP1B patients (B = –0.002, p = 0.053). Z-scores for FN- and LS-BMDs after treatment increased by 0.31 ± 0.10 and 0.58 ± 0.12, respectively, where the increase in LS-BMD correlated with a decrease in PTH (r = –0.72, p = 0.044). All BMD Z-scores were significantly lower in PHP1B patients than in IHP patients for the FN, LS, and TH (–0.20 ± 1.00 versus 1.57 ± 1.07, 1.14 ± 1.41 versus 1.96 ± 1.32, 0.03 ± 1.06 versus 1.67 ± 1.01, respectively, all p < 0.05). Skeletal tissue in PHP1B patients responds to PTH, where heterogenous sensitivities to PTH may exist in different regions of bone. Therefore, it is reasonable to normalize PTH levels when treating PHP1B to avoid negative effects of PTH on bone. © 2017 American Society for Bone and Mineral Research.