bluuebunny/crossref_metadata_2025 huggingface dataset:
« Personne n’est antisémite, mais tout le monde est opposé à l’immigration1 ». Les discours des responsables politiques québécois sur les réfugiés juifs, 1938-1945
Authors: Dubé Sandra
Published: December 2016

Le Canada fut un des nombreux pays où les Juifs européens fuyant les persécutions nazies cherchèrent asile dans les années 1930 et 1940. Un processus pour restreindre l’immigration était entamé depuis déjà plusieurs années et, à l’instar de plusieurs pays, le Canada n’adapta guère ses politiques d’immigration en fonction de ces circonstances tragiques. Les historiens ont cherché à comprendre les raisons de la fermeture du Canada aux réfugiés juifs et dans quelle mesure l’antisémitisme exerça une influence décisive sur cette situation. Si la Grande Dépression et la montée d’un sentiment d’hostilité envers les immigrants furent évoquées, plusieurs chercheurs ont conclu, également, à un manque d’empathie de la population et des hommes politiques pour les persécutions subies par les Juifs. Certains auteurs ont aussi fait référence au climat politique international tendu et radicalisé, marqué par l’ascension des idéologies comme le communisme et le fascisme. L’antisémitisme en vint ainsi à être considéré comme le principal facteur expliquant les politiques canadiennes d’immigration. Plus encore, on prêta au Québec une importante influence sur ces politiques et les Canadiens français furent désignés comme étant au mieux hostiles aux Juifs, sinon carrément antisémites. Alors que les opinions de nombreux acteurs furent étudiées dans ce contexte, le discours des responsables politiques eux-mêmes et spécialement les débats reconstitués de l’Assemblée législative du Québec furent peu explorés, en raison de leur récente disponibilité. Quels furent les propos et les positions des hommes politiques québécois à qui on attribua souvent un antisémitisme de facto ? Dans cet article, nous nous intéressons au discours des responsables politiques québécois sur les réfugiés juifs entre 1938 et 1945. À la lumière d’une mise en contexte du particularisme québécois et à l’aide d’une grille d’analyse du racisme et de sa terminologie, l’analyse de ces discours nous révèle un portrait plus complexe que l’historiographie ne l’a parfois laissé entendre.
The Currencies of Naturalism in Dutch Pronk Still-Life Painting: Luxury, Craft, Envisioned Affluence
Authors: Tokumitsu Miya
Published: December 2016

En tant que mode de représentation, le naturalisme des natures mortes ostentatoires néerlandaises du XVIIe siècle suscite un désir consumériste. Pourtant, comme le mot l’indique, le naturalisme vise la représentation d’objets, de figures, et d’espaces d’une manière qui imite la réalité. Comment les pronkstilleven peuvent-elles prétendre à la vérité de la représentation naturaliste en même temps qu’elles incarnent le luxe, une forme de plaisir personnel déterminé par la valeur sociale ? Pour répondre à cette question, cet essai poursuit trois pistes de réflexion : le statut de la représentation naturaliste comme produit de luxe, les tensions entre l’artisanat et le travail dans ces tableaux, et enfin les distinctions entre l’abondance et l’affluence codifiée dans le naturalisme néerlandais.
Multiple selection filters ensure accurate tail-anchored membrane protein targeting
Authors: Rao Meera , Okreglak Voytek , Chio Un Seng , Cho Hyunju , Walter Peter , Shan Shu-ou
Published: December 2016

Accurate protein localization is crucial to generate and maintain organization in all cells. Achieving accuracy is challenging, as the molecular signals that dictate a protein’s cellular destination are often promiscuous. A salient example is the targeting of an essential class of tail-anchored (TA) proteins, whose sole defining feature is a transmembrane domain near their C-terminus. Here we show that the Guided Entry of Tail-anchored protein (GET) pathway selects TA proteins destined to the endoplasmic reticulum (ER) utilizing distinct molecular steps, including differential binding by the co-chaperone Sgt2 and kinetic proofreading after ATP hydrolysis by the targeting factor Get3. Further, the different steps select for distinct physicochemical features of the TA substrate. The use of multiple selection filters may be general to protein biogenesis pathways that must distinguish correct and incorrect substrates based on minor differences.
Multiple-file vs. single-file endodontics in dental practice: a study in routine care
Authors: Bartols Andreas , Laux Gunter , Walther Winfried
Published: December 2016

Background

Little is known about the differences of rotary multiple file endodontic therapy and single-file reciprocating endodontic treatment under routine care conditions in dental practice. This multicenter study was performed to compare the outcome of multiple-file (MF) and single-file (SF) systems for primary root canal treatment under conditions of general dental practice regarding reduction of pain with a visual analogue scale (VAS 100), improvement of oral-health-related quality of life (OHRQoL) with the german short version of the oral health impact profile (OHIP-G-14) and the speed of root canal preparation.

Materials and Methods

Ten general dental practitioners (GDPs) participated in the study as practitioner-investigators (PI). In the first five-month period of the study, the GDPs treated patients with MF systems. After that, the GDPs treated the patients in the second five-month period with a SF system (WaveOne). The GDPs documented the clinical findings at the beginning and on completion of treatment. The patients documented their pain and OHRQoL before the beginning and before completion of treatment.

Results

A total of 599 patients were included in the evaluation. 280 patients were in the MF group, 319 were in the SF WaveOne group. In terms of pain reduction and improvement in OHIP-G-14, the improvement in both study groups (MF and SF) was very similar based on univariate analysis methods. Pain reduction was 34.4 (SD 33.7) VAS (MF) vs. 35.0 (SD 35.4) VAS (SF) (p = 0.840) and the improvement in OHIP-G-14 score was 9.4 (SD 10.3) (MF) vs. 8.5 (SD 10.2) (SF) (p = 0.365). The treatment time per root canal was 238.9 s (SD 206.2 s) (MF) vs. 146.8 sec. (SD 452.8 sec) (SF) (p = 0.003).

Discussion

Regarding improvement of endodontic pain and OHRQoL measure with OHIP-G-14, there were no statistical significant differences between the SF und the MF systems. WaveOne-prepared root canals significantly faster than MF systems.
Mutational analysis of protein folding inside the ribosome exit tunnel
Authors: Farías‐Rico José Arcadio , Goetz Sara Kathrin , Marino Jacopo , von Heijne Gunnar
Published: December 2016

Recent work has demonstrated that cotranslational folding of proteins or protein domains in, or in the immediate vicinity of, the ribosome exit tunnel generates a pulling force on the nascent polypeptide chain that can be detected using a so‐called translational arrest peptide (AP) engineered into the nascent chain as a force sensor. Here, we show that AP‐based force measurements combined with systematic Ala and Trp scans of a zinc‐finger domain that folds in the exit tunnel can be used to identify the residues that are critical for intraribosomal folding. Our results suggest a general approach to characterize the folded state(s) that may form as a protein domain moves progressively down the ribosome exit tunnel.
MicroRNA‐101b attenuates cardiomyocyte hypertrophy by inhibiting protein kinase C epsilon signaling
Authors: Lee Jong Sub , Yang Dong Kwon , Park Jei Hyoung , Kim Jin Ock , Park Woo Jin , Cho Chunghee , Kim Do Han
Published: December 2016

Previously, a surgical regression model identified microRNA‐101b (miR‐101b) as a potential inhibitor of cardiac hypertrophy. Here, we investigated the antihypertrophic mechanism of miR‐101b using neonatal rat ventricular myocytes. miR‐101b markedly suppressed agonist‐induced cardiac hypertrophy as shown by cell size and fetal gene expression. By systems biology approaches, we identified protein kinase C epsilon (PKCε) as the major target of miR‐101b. Our results from qRT‐PCR, western blot, and luciferase reporter assays confirm that PKCε is a direct target of miR‐101b. In addition, we found that effectors downstream of PKCε (p‐AKT, p‐ERK1/2, p‐NFAT, and p‐GSK3β) are also affected by miR‐101b. Our study reveals a novel inhibitory mechanism for miR‐101b as a negative regulator of cardiac hypertrophy.
A novel approach to assess the ubiquitin‐fold modifier 1‐system in cells
Authors: Ishimura Ryosuke , Obata Miki , Kageyama Shun , Daniel Jens , Tanaka Keiji , Komatsu Masaaki
Published: December 2016

The ubiquitin‐fold modifier 1 (UFM1)‐system, a ubiquitin‐like protein conjugation system, is involved in the development of breast cancer and several hereditary neurological syndromes. However, the molecular mechanisms of UFM1‐related pathogenesis remain unclear. Here, we show that in the absence of UFSP2, a deconjugating enzyme for UFM1, ectopic expression of both UFL1 and UFBP1, which serve as the E3‐ligase complex for the UFM1‐system, dramatically increases UFM1‐conjugate formation at the endoplasmic reticulum. Utilizing this system, we were able to attribute disease‐related isoforms of UBA5, the E1 enzyme for UFM1, to decreased UFM1‐conjugate formation. Our procedure allows the assessment of UFM1‐conjugate formation in cells and the identification of UFM1‐targets, both of which are needed to clarify the pathophysiological role of the UFM1‐system.
Morphodynamic modeling of fluvial channel fill and avulsion time scales during early Holocene transgression, as substantiated by the incised valley stratigraphy of the Trinity River, Texas
Authors: Moran Kaitlin E. , Nittrouer Jeffrey A. , Perillo Mauricio M. , Lorenzo‐Trueba Jorge , Anderson John B.
Published: December 2016

The Trinity River system provides a natural laboratory for linking fluvial morphodynamics to stratigraphy produced by sea‐level rise, because the sediments occupying the Trinity incised valley are well constrained in terms of timing of deposition and facies distribution. Herein, the Trinity River is modeled for a range of base‐level rise rates, avulsion thresholds, and water discharges to explore the effects of backwater‐induced in‐channel sedimentation on channel avulsion. The findings are compared to observed sediment facies to evaluate the capability of a morphodynamic model to reproduce sediment deposition patterns. Base‐level rise produces mobile locations of in‐channel sedimentation and deltaic channel avulsions. For scenarios characteristic of early Holocene sea‐level rise (4.3 mm yr−1), the Trinity fluvial‐deltaic system progrades 13 m yr−1, followed by backstepping of 27 m yr−1. Avulsion is reached at the position of maximum sediment deposition (located 108 km upstream of the outlet) after 3,548 model years, based on sedimentation filling 30% of the channel. Under scenarios of greater base‐level rise, avulsion is impeded because the channel fill threshold is never achieved. Accounting for partitioning of bed‐material sediment between the channel and floodplain influences the timing and location of avulsion over millennial time scales: the time to avulsion is greatly increased. Sedimentation patterns within the valley, modeled and measured, indicate preference toward sandy bed material, and the rates of deposition are substantiated by previous measurements. Although the results here are specific to the Trinity River, the analysis provides a framework that is adaptable to other lowland fluvial‐deltaic systems.
Frequency range of dust detection in space with radio and plasma wave receivers: Theory and application to interplanetary nanodust impacts on Cassini
Authors: Meyer‐Vernet N. , Moncuquet M. , Issautier K. , Schippers P.
Published: December 2016

Wave instruments can detect dust in space via the charges released by impact ionization of fast dust grains. Each hypervelocity dust impact produces an electrostatic pulse whose short risetime is a major property determining the frequency range of detection. We propose a simplified analytical model to calculate this risetime and its variation with grains' mass and photoelectron or ambient plasma density, for pulses in spacecraft potential due to fast interplanetary nanodust impacts. We test these calculations by analyzing the high‐frequency receiver data of the radio and plasma wave instrument during the cruise phase of the Cassini mission between Earth and Jupiter. These data confirm the dependence of the risetime on grains' mass and speed and heliocentric distance predicted by our calculations. Furthermore, the data show that the nanodust properties follow closely the fluctuations of the solar wind velocity component perpendicular to the magnetic field, as predicted by dynamics. The calculations can be generalized to microdust detection on other spacecraft and might explain previous observations left uninterpreted. These calculations are also relevant for the design of wave receivers, by determining the optimal frequency range for dust detection on future missions.
Anisotropic fluid modeling of ionospheric upflow: Effects of low‐altitude anisotropy and thermospheric winds
Authors: Burleigh M. , Zettergren M.
Published: December 2016

A new anisotropic fluid model is developed to describe ionospheric upflow responses to magnetospheric forcing by electric fields and broadband ELF waves at altitudes of 90–2500 km. This model is based on a bi‐Maxwellian ion distribution and solves time‐dependent, nonlinear equations of conservation of mass, momentum, parallel energy, and perpendicular energy for six ion species important to E, F, and topside ionospheric regions. It includes chemical and collisional interactions with the neutral atmosphere, photoionization, and electron impact ionization. This model is used to examine differences between isotropic and anisotropic descriptions of ionospheric upflow driven by DC electric fields, possible effects of low‐altitude (<500 km) wave heating, and impacts of neutral winds on ion upflow. Results indicate that isotropic models may overestimate field‐aligned ion velocity responses by as much as ∼48%. Simulations also show significant ionospheric responses at low altitudes to wave heating for very large power spectral densities, but ion temperature anisotropies below the F region peak are dominated by frictional heating from DC electric fields. Neutral winds are shown to play an important role regulating ion upflow. Thermospheric winds can enhance or suppress upward fluxes driven by DC and BBELF fields by 10–20% for the cases examined. The time history of the neutral winds also affects the amount of ionization transported to higher altitudes by DC electric fields.
On the contribution of thermal excitation to the total 630.0 nm emissions in the northern cusp ionosphere
Authors: Kwagala Norah Kaggwa , Oksavik Kjellmar , Lorentzen Dag A. , Johnsen Magnar G.
Published: December 2016

Direct impact excitation by precipitating electrons is believed to be the main source of 630.0 nm emissions in the cusp ionosphere. However, this paper investigates a different source, 630.0 emissions caused by thermally excited atomic oxygen O(1D) when high electron temperature prevail in the cusp. On 22 January 2012 and 14 January 2013, the European Incoherent Scatter Scientific Association (EISCAT) radar on Svalbard measured electron temperature enhancements exceeding 3000 K near magnetic noon in the cusp ionosphere over Svalbard. The electron temperature enhancements corresponded to electron density enhancements exceeding 1011 m−3 accompanied by intense 630.0 nm emissions in a field of view common to both the EISCAT Svalbard radar and a meridian scanning photometer. This offered an excellent opportunity to investigate the role of thermally excited O(1D) 630.0 nm emissions in the cusp ionosphere. The thermal component was derived from the EISCAT Radar measurements and compared with optical data. For both events the calculated thermal component had a correlation coefficient greater than 0.8 to the total observed 630.0 nm intensity which contains both thermal and particle impact components. Despite fairly constant solar wind, the calculated thermal component intensity fluctuated possibly due to dayside transients in the aurora.
The plasmapause formation seen from meridian perspective by KAGUYA
Authors: Murakami Go , Yoshioka Kazuo , Yamazaki Atsushi , Nishimura Yukitoshi , Yoshikawa Ichiro , Fujimoto Masaki
Published: December 2016

Observations by the extreme ultraviolet (EUV) imager on board the IMAGE spacecraft revealed that the formation of a sharp plasmapause occurs in the postmidnight sector soon (<1 h) after the convection enhancement. These results cannot be explained simply by the conventional theory of the plasmapause formation that the plasmapause coincides with the last closed equipotential of the convection electric field superposed on the Earth's corotation electric field. However, due to the limitation that the EUV imager provides information on only the azimuthal distribution of the plasmapause, the formation mechanism still remains an open issue. Now global images of the plasmasphere from meridian perspective become available, thanks to the telescope of extreme ultraviolet (TEX) instrument on board the KAGUYA spacecraft. Here we studied the plasmapause formation mechanism by analyzing the sequential TEX images of an erosion event during the geomagnetic disturbance (Kp = 5) on 1–2 May 2008. The temporal evolution of the plasmapause locations at postmidnight observed by TEX agreed with those predicted by the dynamic simulations based on the interchange mechanism. Furthermore, the He+ column density in the nightside plasmasphere decreased by ~30% only at the low latitudes (<20°) during the enhanced convection period. This suggests that the plasmapause formation occurs first near the equatorial region during a geomagnetic disturbance, and it agrees with the plasmapause formation mechanism based on the interchange instability. Although we cannot conclude exclusively for the interchange mechanism, this is the first study to present the plasmapause formation viewed from the meridian perspective.
Pulsations of the polar cusp aurora at Saturn
Authors: Palmaerts B. , Radioti A. , Roussos E. , Grodent D. , Gérard J.‐C. , Krupp N. , Mitchell D. G.
Published: December 2016

The magnetospheric cusp is a region connecting the interplanetary environment to the ionosphere and enabling solar wind particles to reach the ionosphere. We report the detection of several isolated high‐latitude auroral emissions with the Ultraviolet Imaging Spectrograph of the Cassini spacecraft. We suggest that these auroral spots, located in the dawn‐to‐noon sector and poleward of the main emission, are the ionospheric signatures of the magnetospheric cusp, in agreement with some previous observations with the Hubble Space Telescope. The high‐latitude cusp auroral signature has been associated with high‐latitude lobe reconnection in the presence of a southward interplanetary magnetic field. The occurrence rate of the polar cusp aurora suggests that lobe reconnection is frequent at Saturn. Several auroral imaging sequences reveal a quasiperiodic brightening of the polar cusp aurora with a period in the range of 60 to 70 min. Similar pulsations in the energetic electron fluxes and in the azimuthal component of the magnetic field are simultaneously observed by Cassini instruments, suggesting the presence of field‐aligned currents. Pulsed dayside magnetopause reconnection is a likely common triggering process for the cusp auroral brightenings at Saturn and the quasiperiodic pulsations in the high‐latitude energetic electron fluxes.
Evidence for a transient hydromechanical and frictional faulting response during the 2011 Mw 5.6 Prague, Oklahoma earthquake sequence
Authors: Norbeck J. H. , Horne R. N.
Published: December 2016

Mechanisms for the delayed triggering between the Mw 4.8 foreshock and Mw 5.6 main shock of the 2011 earthquake sequence near Prague, Oklahoma, USA, were investigated using a coupled fluid flow and fault mechanics numerical model. Because the stress orientations, stress magnitudes, fault geometry, and earthquake source mechanisms at the Prague site have been well characterized by previous studies, this particular earthquake sequence offered an opportunity to explore the range of physical processes and in situ fault properties that might be consistent with the 20 h delayed triggering effect observed at the site. Our numerical experiments suggest that an initial undrained response resulting from elastic stress transfer from the foreshock followed by transient fluid flow along the fault may have contributed to the earthquake nucleation process. The results of the numerical experiments were used to constrain fault compliance and fault transmissivity for the fault that hosted the Mw 5.6 event. Relatively compliant behavior in response to changes in normal stress, corresponding to Skempton pore pressure coefficients near 1, was consistent with the field observations. Fault transmissivity was estimated to range from 10−18 to 10−15 m3. This study has implications for understanding hydraulic properties, frictional properties, and faulting behavior of basement faults in Oklahoma that are large enough to host damaging earthquakes.
Bipolar lightning flashes observed at the Säntis Tower: Do we need to modify the traditional classification?
Authors: Azadifar Mohammad , Rachidi Farhad , Rubinstein Marcos , Rakov Vladimir A. , Paolone Mario , Pavanello Davide
Published: December 2016

We present and discuss current waveforms associated with 13 bipolar lightning flashes recorded at the Säntis Tower during the period from June 2010 to January 2015. During this period, a total of 427 flashes were recorded, of which 13 (3%) were classified as bipolar flashes. The majority of the recorded flashes (10 out of 13) exhibited a polarity reversal during the initial continuous current, therefore belonging to Category I according to the classification proposed by Rakov (2003). Of the three remaining flashes, two were characterized by different polarities of the initial stage current and the following return stroke or strokes (Category II), and one flash involved return strokes of opposite polarity within the same flash (Category III). In Category I bipolar flashes, the polarity reversal is usually assumed to be associated with in‐cloud processes. However, two of our 10 Category I flashes appeared to be each a sequence of two upward discharges of opposite polarity, initiated from the tower within tens of milliseconds of each other. This is the first time that such a sequence has been observed from the same tower. We suggest that the traditional classification of bipolar flashes should be modified to distinguish between two types of Category I flashes: those in which the polarity reversal during the initial stage is associated with in‐cloud processes (Category Ia) and those in which the polarity reversal is due to initiation of two opposite‐polarity leaders from the tower (Category Ib).
Atmospheric moisture budget and its regulation on the variability of summer precipitation over the Tibetan Plateau
Authors: Wang Ziqian , Duan Anmin , Yang Song , Ullah Kalim
Published: December 2016

Based on station observations and reanalysis data sets, the atmospheric moisture budget and its critical role in regulating the variability of summer precipitation over the Tibetan Plateau (TP) are investigated. Results indicate that the yearly variability of summer precipitation over the southern TP (STP) is mainly controlled by remote moisture transport. Local surface evaporation presents an infinitesimal interannual fluctuation, but it cannot be ignored since it is a large component of total precipitation amount in every summer. Although the incoming moisture transport at the western boundary of STP is much weaker than that at the southern boundary, it primarily influences the temporal variation of STP summer precipitation. Further analysis shows that the summer North Atlantic Oscillation (NAO) also possesses a significant impact on the variation of STP summer precipitation. A strong NAO apparently weakens the moisture transport at the western boundary, inducing less precipitation over the STP. When the NAO is strong, wave‐activity flux obviously diverges eastward from the subtropical high over northwestern Europe. Then such flux converges toward the western TP, which weakens the baroclinic vertical structure of atmospheric circulation over the TP. The NAO also influences the meridional position of the Asian jet stream and modulates the specific humidity and moisture transport at the western boundary of STP. In addition, the dynamic processes of the atmosphere are more important than the thermodynamic processes in regulating the variability of TP summer precipitation.
A stationary phase solution for mountain waves with application to mesospheric mountain waves generated by Auckland Island
Authors: Broutman Dave , Eckermann Stephen D. , Knight Harold , Ma Jun
Published: December 2016

A relatively general stationary phase solution is derived for mountain waves from localized topography. It applies to hydrostatic, nonhydrostatic, or anelastic dispersion relations, to arbitrary localized topography, and to arbitrary smooth vertically varying background temperature and vector wind profiles. A simple method is introduced to compute the ray Jacobian that quantifies the effects of horizontal geometrical spreading in the stationary phase solution. The stationary phase solution is applied to mesospheric mountain waves generated by Auckland Island during the Deep Propagating Gravity Wave Experiment. The results are compared to a Fourier solution. The emphasis is on interpretations involving horizontal geometrical spreading. The results show larger horizontal geometrical spreading for nonhydrostatic waves than for hydrostatic waves in the region directly above the island; the dominant effect of horizontal geometrical spreading in the lower ∼30 km of the atmosphere, compared to the effects of refraction and background density variation; and the enhanced geometrical spreading due to directional wind in the approach to a critical layer in the mesosphere.
Regional pollution and its formation mechanism over North China Plain: A case study with ceilometer observations and model simulations
Authors: Zhu Xiaowan , Tang Guiqian , Hu Bo , Wang Lili , Xin Jinyuan , Zhang Junke , Liu Zirui , Münkel Christoph , Wang Yuesi
Published: December 2016

To investigate regional haze formation, ceilometer observations at the Beijing (BJ), Shijiazhuang (SJZ), Tianjin (TJ), and Qinhuangdao (QHD) stations were conducted from 12 October to 10 November 2014, to obtain the boundary layer height (BLH) and the attenuated backscattering coefficients (ABC). Particles at the four stations were highly correlated, whereas precursors of particles exhibited weaker correlations. By analyzing the typical haze episode between 21 and 26 October 2014, we found that warm advection at a height of 850 hPa from the Loess Plateau caused a gradual decline in the regional BLH. Moreover, water vapor transported from the southern NCP caused the column water vapor amount to increase from 0.015 kg m−2 to 0.042 kg m−2 in the boundary layer in BJ. As southerly transport prevailed during the transition period, ABC profiles in the BJ, TJ, and QHD stations showed a bilayer pattern, and the second layer was between 500 and 1000 m. As a result, the ABC integrations of BJ and TJ increased by 74.2 and 139.7%, respectively. During the polluted period, due to the weakened transport effect, the ABC integrations of the four stations decreased by 7.9, 18.2, 16.2, and 28.2%, respectively. Contributions of the secondary inorganic species (sulfate, nitrate, and ammonium) at BJ increased from 37.3% to 56.9%, and the mean particle size increased from 107.8 nm to 140.8 nm. Emissions in southern NCP should be mitigated during the transition period, whereas the inorganic precursors are the most important air pollutants during the polluted period.
Vascular endothelial growth factor suppresses TNFSF15 production in endothelial cells by stimulating miR‐31 and miR‐20a expression via activation of Akt and Erk signals
Authors: Deng Hui‐Ting , Liu Hai‐Lin , Zhai Bei‐Bei , Zhang Kun , Xu Guo‐Ce , Peng Xue‐Mei , Zhang Qiang‐Zhe , Li Lu‐Yuan
Published: December 2016

Tumor necrosis factor superfamily‐15 (TNFSF15; VEGI; TL1A) is a negative modulator of angiogenesis for blood vessel homeostasis and is produced by endothelial cells in a mature vasculature. It is known to be downregulated by vascular endothelial growth factor (VEGF), a major regulator of neovascularization but the mechanism of this interaction is unclear. Here we report that VEGF is able to stimulate the production of two microRNAs, miR‐20a and miR‐31, which directly target the 3′‐UTR of TNFSF15. Additionally, we show that two VEGF‐stimulated cell growth signals, Erk and Akt, are responsible for promoting the expression of miR‐20a and miR‐31. Treatment of human umbilical vein endothelial cells (HUVECs) with Akt inhibitor LY294002 results in diminished miR‐20a and miR‐31 production, while Erk inhibitor U0126 prevented VEGF‐stimulated expression of miR‐20a but not that of miR‐31. Furthermore, inactivation of either Erk or Akt signals restores TNFSF15 gene expression. In an angiogenesis assay, elevated miR‐20a or miR‐31 levels in HUVECs leads to enhancement of capillary‐like tubule formation in vitro, whereas lowered miR‐20a and miR‐31 levels results in an inhibition. These findings are consistent with the view that miR‐20a and miR‐31 mediate VEGF‐induced downregulation of TNFSF15. Targeting these microRNA molecules may therefore provide an effective approach to inhibit angiogenesis.
Sucralose activates an ERK1/2–ribosomal protein S6 signaling axis
Authors: Guerra Marcy L. , Kalwat Michael A. , McGlynn Kathleen , Cobb Melanie H.
Published: December 2016

The sweetener sucralose can signal through its GPCR receptor to induce insulin secretion from pancreatic β cells, but the downstream signaling pathways involved are not well‐understood. Here we measure responses to sucralose, glucagon‐like peptide 1, and amino acids in MIN6 β cells. Our data suggest a signaling axis, whereby sucralose induces calcium and cAMP, activation of ERK1/2, and site‐specific phosphorylation of ribosomal protein S6. Interestingly, sucralose acted independently of mTORC1 or ribosomal S6 kinase (RSK). These results suggest that sweeteners like sucralose can influence β‐cell responses to secretagogues like glucose through metabolic as well as GPCR‐mediated pathways. Future investigation of novel sweet taste receptor signaling pathways in β cells will have implications for diabetes and other emergent fields involving these receptors.
Post‐translational modifications of Annexin A2 are linked to its association with perinuclear nonpolysomal mRNP complexes
Authors: Aukrust Ingvild , Rosenberg Linn Andersen , Ankerud Mia Madeleine , Bertelsen Vibeke , Hollås Hanne , Saraste Jaakko , Grindheim Ann Kari , Vedeler Anni
Published: December 2016

Various post‐translational modifications (PTMs) regulate the localisation and function of the multifunctional protein Annexin A2 (AnxA2). In addition to its various tasks as a cytoskeletal‐ and membrane‐associated protein, AnxA2 can function as a trans‐acting protein binding to cis‐acting sequences of specific mRNAs. In the present study, we have examined the role of Ser25 phosphorylation in subcellular localisation of AnxA2 and its interaction with mRNP complexes. Subcellular fractionation and confocal microscopy of rat neuroendocrine PC12 cells showed that Ser25‐phosphorylated AnxA2 (pSer25AnxA2) is absent from the nucleus and mainly localised to the perinuclear region, evidently associating with both membranes and cytoskeletal elements. Perinuclear targeting of AnxA2 was abolished by inhibition of protein kinase C activity, which resulted in cortical enrichment of the protein. Although oligo(dT)‐affinity purification of mRNAs revealed that pSer25AnxA2 associates with nonpolysomal, translationally inactive mRNP complexes, it displayed only partial overlap with a marker of P‐bodies. The phosphorylated protein is present as high‐molecular‐mass forms, indicating that it contains additional covalent PTMs, apparently triggered by its Ser25 phosphorylation. The subcellular distributions of these forms clearly differ from the main form of AnxA2 and are also distinct from that of Tyr23‐phosphorylated AnxA2. Immunoprecipitation verified that these high‐molecular‐mass forms are due to ubiquitination and/or sumoylation. Moreover, these results indicate that Ser25 phosphorylation and ubiquitin/SUMO1 conjugation of AnxA2 promote its association with nonpolysomal mRNAs, providing evidence of a possible mechanism to sequester a subpopulation of mRNAs in a translationally inactive and transport competent form at a distinct subcellular localisation.
Iridium‐Catalyzed Asymmetric Hydrogenation of Tosylamido‐Substituted Pyrazines for Constructing Chiral Tetrahydropyrazines with an Amidine Skelton
Authors: Higashida Kosuke , Nagae Haruki , Mashima Kazushi
Published: December 2016

Dinuclear triply chloro‐bridged iridium(III) complexes bearing chiral diphosphine ligands catalyze the asymmetric hydrogenation of tosylamido‐substituted pyrazines to give the corresponding chiral tetrahydropyrazines with an amidine skeleton in high yield and with high enantioselectivity. Addition of N,N‐dimethylanilinium bromide enhanced the catalytic activity of the iridium complexes and also increased the enantioselectivity of the products by trapping the hydrogenated amine products with HBr from N,N‐dimethylanilinium bromide. The amidine skeleton of the products could be transformed to give chiral piperazinones and piperazines without loss of enantioselectivity.

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Enzymatic catalyzed reactive dividing wall column: Experiments and model validation
Authors: Egger Torben , Fieg Georg
Published: December 2016

A novel process for the integration of chemical reaction and product separation is proposed: the enzymatic catalyzed reactive dividing wall column (eRDWC). The eRDWC combines the highly integrated and complex reactive dividing wall column (RDWC) with the use of a very selective enzymatic catalyst. This apparatus enables the simultaneous production and separation of up to 4 pure product streams. Comprehensive experiments with the reference system of a hexanol and butyl acetate transesterification in a DN 65 pilot scale column show the feasibility of stable steady state operations for this process. A rigorous model for the plant design of an eRDWC wall column is developed. The reaction kinetics and vapor‐liquid‐equilibria for the reference system are measured and implemented in the model. The model is successfully validated using the acquired experimental data. The application of enzymes in continuous reactive distillation processes has the potential to increase the selectivity at milder process conditions. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2198–2211, 2017
Multiple isolas in steady‐state characteristics of fluidized bed catalytic reactors
Authors: Bizon Katarzyna
Published: December 2016

Steady‐state characteristics of a catalytic fluidized bed reactor are analyzed. A two‐phase bubbling model is used for the description of a fluidized bed of a catalyst. Particular attention is focused on the theoretical and technological consequences of a newly observed steady‐state behavior. Features of the model are presented in terms of steady‐state structures, stability, solution multiplicity, and process efficiency. The possibility of an occurrence of multiple isolas of steady states is demonstrated for two simple kinetic models. Depending on the multiplicity region they belong to, multiple isolas are referred to as first type or second type isolas. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2107–2116, 2017
Integrated adsorbent‐process optimization for carbon capture and concentration using vacuum swing adsorption cycles
Authors: Khurana Maninder , Farooq Shamsuzzaman
Published: December 2016

A novel approach for integrated adsorbent and process design is proposed. The traditional pressure or vacuum swing adsorption (PSA) / vacuum swing adsorption (VSA) process optimization for chosen objectives, where operating conditions are the decision variables, and CO2 purity and recovery are constraints, is expanded to include adsorbent isotherm characteristics as additional decision variables. Two VSA cycles, namely a four‐step process1, currently known to have the lowest energy consumption for CO2 capture and concentration (CCC), and a six‐step process2, recently proven to have a wider operating window for the evacuation pressure, have been investigated in the current study. The integrated optimization results simultaneously provide the lower bound of minimum energy and upper bound of maximum productivity for CCC achievable from the two VSA processes along with the operating conditions and the corresponding isotherm shapes necessary to achieve them. It may be viewed as an enabler for adsorbent design or expedient adsorbent search by process inversion. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2987–2995, 2017
Novel method for determination of gas solubilities in low vapor pressure liquids
Authors: Zubeir L. F. , Lipman P. J. L. , van der Schaaf J. , Awwad N. , Peters C. J. , Kroon M. C.
Published: December 2016

A modified version of a standard device for measuring gas adsorption and desorption isotherms and surface area of adsorbents and catalysts (ASAP (Accelerated Surface Area and Porosimetry System) 2020, Micromeritics USA) is used for the first time to measure gas solubilities (i.e., CO2) in low vapor pressure liquids (i.e., the IUPAC standard ionic liquid 1‐hexyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([C6mim][Tf2N])) in the Henry's law region. The solubility data are in very good agreement with the reported data in literature. Furthermore, the Henry's law constants are calculated from the solubility data and compared to the experimental data found in literature. The results from this study demonstrate that Micromeritics ASAP 2020 is a suitable apparatus for gas absorption by solvents with reduced vapor pressures. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2981–2986, 2017
Robustness of bioprocess feedback control to biodiversity
Authors: Mairet Francis , Bernard Olivier
Published: December 2016

The design of control laws for bioprocesses is generally based on simplified single‐species models. Biodiversity is nonetheless inherent in any bioreactor where contamination leads to a mixture of different species or strains. This paper proposes to define and study the robustness to biodiversity of bioprocess control laws: given a control law designed for one species, what happens when additional species are present? is the approach is illustrated with a well‐used control law which regulates substrate concentration using measurement of growth activity. Depending on the properties of the additional species, the control law can lead to the required objective, but also to an undesired monospecies equilibrium point, coexistence, or even a failure point. Finally, for this case, the robustness can be improved by a saturation of the control. Robustness to biodiversity is a difficult issue which should be better understood and accounted for in the control design. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2742–2750, 2017
Oberflächenfacettierung und Rekonstruktion von Ceroxid‐ Nanopartikeln
Authors: Yang Chengwu , Yu Xiaojuan , Heißler Stefan , Nefedov Alexei , Colussi Sara , Llorca Jordi , Trovarelli Alessandro , Wang Yuemin , Wöll Christof
Published: December 2016

Die Anordnung der Atome an Metalloxid‐Oberflächen bestimmt deren physikalische und chemische Eigenschaften. Sie ist für viele Anwendungen von entscheidender Bedeutung, vor allem bei der heterogenen Katalyse und der Photokatalyse. Während für die Bestimmung von Oberflächenstrukturen von makroskopischen Einkristallen etablierte Methoden zur Verfügung stehen, stellen derartige Analysen für Nanopartikel (NP) eine große Herausforderung dar. In unserer wird CO als Sondenmolekül zur Bestimmung der Struktur von Oberflächen stabförmiger Ceroxid‐NP eingesetzt. Nach Kalibrierung der CO‐Streckschwingungsfrequenzen anhand von Ergebnissen für verschiedene Ceroxid‐Einkristalloberflächen kommen wir zu dem Schluss, dass die stabförmigen NP entgegen der Erwartung (111)‐facettierte Oberflächen aufweisen. Dieser Befund hat wichtige Folgen für das Verständnis der komplexen Oberflächenchemie dieser katalytisch besonders aktiven Ceroxid‐NP und liefert die Basis für ein rationales Design von Katalysatormaterialien im Nanomaßstab.
Synthesis of Discrete Oligomers by Sequential PET‐RAFT Single‐Unit Monomer Insertion
Authors: Xu Jiangtao , Fu Changkui , Shanmugam Sivaprakash , Hawker Craig J. , Moad Graeme , Boyer Cyrille
Published: December 2016

Uniform synthetic polymers with precisely defined molar mass and monomer sequence (primary structure) have many potential high‐value applications. However, a robust and versatile synthetic strategy for these materials remains one of the great challenges in polymer synthesis. Herein we describe proof‐of‐principle experiments for a modular strategy to produce discrete oligomers by a visible‐light‐mediated radical chain process. We utilize the high selectivity provided by photo‐induced electron/energy transfer (PET) activation to develop efficient single unit monomer insertion (SUMI) into reversible addition–fragmentation chain‐transfer (RAFT) agents. A variety of discrete oligomers (single unit species, dimers, and, for the first time, trimers) have been synthesized by sequential SUMI in very high yield under mild reaction conditions. The trimers were used as building blocks for the construction of uniform hexamers and graft copolymers with precisely defined branches.
Surface Faceting and Reconstruction of Ceria Nanoparticles
Authors: Yang Chengwu , Yu Xiaojuan , Heißler Stefan , Nefedov Alexei , Colussi Sara , Llorca Jordi , Trovarelli Alessandro , Wang Yuemin , Wöll Christof
Published: December 2016

The surface atomic arrangement of metal oxides determines their physical and chemical properties, and the ability to control and optimize structural parameters is of crucial importance for many applications, in particular in heterogeneous catalysis and photocatalysis. Whereas the structures of macroscopic single crystals can be determined with established methods, for nanoparticles (NPs), this is a challenging task. Herein, we describe the use of CO as a probe molecule to determine the structure of the surfaces exposed by rod‐shaped ceria NPs. After calibrating the CO stretching frequencies using results obtained for different ceria single‐crystal surfaces, we found that the rod‐shaped NPs actually restructure and expose {111} nanofacets. This finding has important consequences for understanding the controversial surface chemistry of these catalytically highly active ceria NPs and paves the way for the predictive, rational design of catalytic materials at the nanoscale.
Consensus of Delayed Multi‐agent Systems via Intermittent Impulsive Control
Authors: Yang Shasha , Liao Xiaofeng , Liu Yanbing , Chen Xin , Ge Dingling
Published: December 2016

A novel intermittent impulsive scheme is presented to realize consensus of multi‐agent systems with time‐varying delay in this paper because intermittent impulsive control may break through the limitation of upper bound of impulsive intervals in general impulsive control in our consensus scheme. Instead of activating all the time, we introduce the intermittent impulsive control approach into the delayed multi‐agent systems where the impulsive controller is only functioned in the control windows. Based on the algebraic graph theory, the Lyapunov stability theory, and Halanay inequality matrix theory, some adequate conditions are proposed to guarantee the consensus of delayed multi‐agent systems via pinning intermittent impulsive control. Simulation results are provided ultimately to verify the validity of the proposed control mechanism.
Loop‐Shaping Feedback and Feedforward Control for Networked Systems With Saturation and Delay
Authors: Wigren Torbjörn
Published: December 2016

The paper proposes a new robust networked controller, for example suitable for packet data transfer control in wireless sensor networks with uncertain delays. The method adjusts a linear H2 loop‐shaping design towards consistency with a long delay and a saturation in the feedback loop, where the saturation results because of the one‐directional packet flow. Feedforward from a measurable disturbance is integrated in the design. By formally extending recently derived sensitivity function constraints to include feedforward, a subset of the
stability region is pre‐computed using the stability inequality of the Popov criterion. A robustly stable controller is then selected in the stability region. The new controller design method is applied to internet data flow control supporting 5G wireless connectivity. The results indicate a possible enhancement of the robustness against feedback delay uncertainty with a factor of 3‐4. Such robustness should be beneficial for example for packet data relying with variable routing over ad hoc wireless sensor networks.
Inhibition of glucuronidation and oxidative metabolism of buprenorphine using GRAS compounds or dietary constituents/supplements: in vitro proof of concept
Authors: Maharao Neha V. , Joshi Anand A. , Gerk Phillip M.
Published: December 2016

The present study investigated the potential of generally recognized as safe (GRAS) compounds or dietary substances to inhibit the presystemic metabolism of buprenorphine and to increase its oral bioavailability. Using IVIVE, buprenorphine extraction ratios in intestine and liver were predicted as 96% and 71%, respectively. In addition, the relative fraction of buprenorphine metabolized by oxidation and glucuronidation in these two organs was estimated using pooled human intestinal and liver microsomes. In both organs, oxidation appeared to be the major metabolic pathway with a 6 and 4 fold higher intrinsic clearance than glucuronidation in intestine and liver, respectively. The oral bioavailability of buprenorphine was predicted to be 1.16%. Inhibition of 75% and 50% of intestinal and hepatic presystemic metabolism would result in an Foral of 49%, which is comparable to the bioavailability of sublingual buprenorphine. In human liver microsomes, chrysin, curcumin, ginger extract, hesperitin, magnolol, quercetin and silybin inhibited ≥50% glucuronidation, whereas chrysin, curcumin, ginger extract, 6‐gingerol, pterostilbene, resveratrol and silybin exhibited ≥30% inhibition of oxidation. In human intestinal microsomes, curcumin, ginger extract, α‐mangostin, quercetin and silybin inhibited ≥50% glucuronidation while chrysin, ginger extract, α‐mangostin, pterostilbene and resveratrol exhibited ≥30% inhibition of oxidation. These results demonstrate the feasibility of our proposed approach of using GRAS or dietary compounds to inhibit the presystemic metabolism of buprenorphine and thus improve its oral bioavailability. An oral buprenorphine formulation containing these inhibitors or their combinations has promising potential to replace sublingual buprenorphine. Copyright © 2016 John Wiley & Sons, Ltd.