bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of noble metal–titania core–shell nanostructures with tunable shell thickness
Authors: Bartosewicz Bartosz , Michalska-Domańska Marta , Liszewska Malwina , Zasada Dariusz , Jankiewicz Bartłomiej J
Published: October 2017

Core–shell nanostructures have found applications in many fields, including surface enhanced spectroscopy, catalysis and solar cells. Titania-coated noble metal nanoparticles, which combine the surface plasmon resonance properties of the core and the photoactivity of the shell, have great potential for these applications. However, the controllable synthesis of such nanostructures remains a challenge due to the high reactivity of titania precursors. Hence, a simple titania coating method that would allow better control over the shell formation is desired. A sol–gel based titania coating method, which allows control over the shell thickness, was developed and applied to the synthesis of Ag@TiO2 and Au@TiO2 with various shell thicknesses. The morphology of the synthesized structures was investigated using scanning electron microscopy (SEM). Their sizes and shell thicknesses were determined using tunable resistive pulse sensing (TRPS) technique. The optical properties of the synthesized structures were characterized using UV–vis spectroscopy. Ag@TiO2 and Au@TiO2 structures with shell thickness in the range of ≈40–70 nm and 90 nm, for the Ag and Au nanostructures respectively, were prepared using a method we developed and adapted, consisting of a change in the titania precursor concentration. The synthesized nanostructures exhibited significant absorption in the UV–vis range. The TRPS technique was shown to be a very useful tool for the characterization of metal–metal oxide core–shell nanostructures.
Enzymatic separation of epimeric 4-C-hydroxymethylated furanosugars: Synthesis of bicyclic nucleosides
Authors: Rana Neha , Kumar Manish , Khatri Vinod , Maity Jyotirmoy , Prasad Ashok K
Published: October 2017

Conversion of D-glucose to 4-C-hydroxymethyl-1,2-O-isopropylidene-α-D-ribofuranose, which is a key precursor for the synthesis of different types of bicyclic/spiro nucleosides, led to the formation of an inseparable 1:1 mixture of the desired product and 4-C-hydroxymethyl-1,2-O-isopropylidene-α-D-xylofuranose. A convenient environment friendly Novozyme®-435 catalyzed selective acetylation methodology has been developed for the separation of an epimeric mixture of ribo- and xylotrihydroxyfuranosides in quantitative yields. The structure of both the monoacetylated epimers, i.e., 5-O-acetyl-4-C-hydroxymethyl-1,2-O-isopropylidene-α-D-ribo- and xylofuranose obtained by enzymatic acetylation, has been confirmed by an X-ray study on their corresponding 4-C-p-toluenesulfonyloxymethyl derivatives. Furthermore, the two separated epimers were used for the convergent synthesis of two different types of bicyclic nucleosides, which confirms their synthetic utility.
Exploring the Efficacy and Limitations of Shock-cooling Models: New Analysis of Type II Supernovae Observed by the Kepler Mission
Authors: Rubin Adam , Gal-Yam Avishay
Published: October 2017

Modern transient surveys have begun discovering and following supernovae (SNe) shortly after first light—providing systematic measurements of the rise of Type II SNe. We explore how analytic models of early shock-cooling emission from core-collapse SNe can constrain the progenitor’s radius, explosion velocity, and local host extinction. We simulate synthetic photometry in several realistic observing scenarios; assuming the models describe the typical explosions well, we find that ultraviolet observations can constrain the progenitor’s radius to a statistical uncertainty of ±10%–15%, with a systematic uncertainty of ±20%. With these observations the local host extinction (A

V
) can be constrained to a factor of two and the shock velocity to ±5% with a systematic uncertainty of ±10%. We also reanalyze the SN light curves presented by Garnavich et al. (2016) and find that KSN 2011a can be fit by a blue supergiant model with a progenitor radius of

, while KSN 2011d can be fit with a red supergiant model with a progenitor radius of

. Our results do not agree with those of Garnavich et al. Moreover, we re-evaluate their claims and find that there is no statistically significant evidence for a shock-breakout flare in the light curve of KSN 2011d.
Forming Different Planetary Architectures. I. The Formation Efficiency of Hot Jupiters from High-eccentricity Mechanisms
Authors: Wang Ying , Zhou Ji-lin , hui-gen Liu , Meng Zeyang
Published: October 2017

Exoplanets discovered over the past decades have provided a new sample of giant exoplanets: hot Jupiters. For lack of enough materials in the current locations of hot Jupiters, they are perceived to form outside the snowline. Then, they migrate to the locations observed through interactions with gas disks or high-eccentricity mechanisms. We examined the efficiencies of different high-eccentricity mechanisms for forming hot Jupiters in near-coplanar multi-planet systems. These mechanisms include planet–planet scattering, the Kozai–Lidov mechanism, coplanar high-eccentricity migration, and secular chaos, as well as other two new mechanisms that we present in this work, which can produce hot Jupiters with high inclinations even in retrograde. We find that the Kozai–Lidov mechanism plays the most important role in producing hot Jupiters among these mechanisms. Secular chaos is not the usual channel for the formation of hot Jupiters due to the lack of an angular momentum deficit within

(periods of the inner orbit). According to comparisons between the observations and simulations, we speculate that there are at least two populations of hot Jupiters. One population migrates into the boundary of tidal effects due to interactions with the gas disk, such as ups And b, WASP-47 b, and HIP 14810 b. These systems usually have at least two planets with lower eccentricities, and remain dynamically stable in compact orbital configurations. Another population forms through high-eccentricity mechanisms after the excitation of eccentricity due to dynamical instability. These kinds of hot Jupiters usually have Jupiter-like companions in distant orbits with moderate or high eccentricities.
Toward Space-like Photometric Precision from the Ground with Beam-shaping Diffusers
Authors: Stefansson Gudmundur , Mahadevan Suvrath , Hebb Leslie , Wisniewski John , Huehnerhoff Joseph , Morris Brett , Halverson Sam , Zhao Ming , Wright Jason , O’rourke Joseph , Knutson Heather , Hawley Suzanne , Kanodia Shubham , Li Yiting , Hagen Lea M. Z. , Liu Leo J. , Beatty Thomas , Bender Chad , Robertson Paul , Dembicky Jack , Gray Candace , Ketzeback William , McMillan Russet , Rudyk Theodore
Published: October 2017

We demonstrate a path to hitherto unachievable differential photometric precisions from the ground, both in the optical and near-infrared (NIR), using custom-fabricated beam-shaping diffusers produced using specialized nanofabrication techniques. Such diffusers mold the focal plane image of a star into a broad and stable top-hat shape, minimizing photometric errors due to non-uniform pixel response, atmospheric seeing effects, imperfect guiding, and telescope-induced variable aberrations seen in defocusing. This PSF reshaping significantly increases the achievable dynamic range of our observations, increasing our observing efficiency and thus better averages over scintillation. Diffusers work in both collimated and converging beams. We present diffuser-assisted optical observations demonstrating

ppm precision in 30 minute bins on a nearby bright star 16 Cygni A (V = 5.95) using the ARC 3.5 m telescope—within a factor of ∼2 of Kepler's photometric precision on the same star. We also show a transit of WASP-85-Ab (V = 11.2) and TRES-3b (V = 12.4), where the residuals bin down to

ppm in 30 minute bins for WASP-85-Ab—a factor of ∼4 of the precision achieved by the K2 mission on this target—and to 101 ppm for TRES-3b. In the NIR, where diffusers may provide even more significant improvements over the current state of the art, our preliminary tests demonstrated

ppm precision for a K

S
 = 10.8 star on the 200 inch Hale Telescope. These photometric precisions match or surpass the expected photometric precisions of TESS for the same magnitude range. This technology is inexpensive, scalable, easily adaptable, and can have an important and immediate impact on the observations of transits and secondary eclipses of exoplanets.
Dwarf Galaxy Discoveries from the KMTNet Supernova Program. I. The NGC 2784 Galaxy Group*
Authors: Park Hong Soo , Moon Dae-Sik , Zaritsky Dennis , Pak Mina , Lee Jae-Joon , Kim Sang Chul , Kim Dong-Jin , Cha Sang-Mok
Published: October 2017

We present BVI surface photometry of 31 dwarf galaxy candidates discovered in a deep image stack from the KMTNet Supernova Program of ∼30 square degrees centered on the nearby NGC 2784 galaxy group. Our final images have a 3σ surface brightness detection limit of

mag arcsec−2. The faintest central surface brightness that we measure is

mag arcsec−2. If these candidates are at the distance of NGC 2784, then they have absolute magnitudes greater than

mag and effective radii larger than 170 pc. Their radial number density decreases exponentially with distance from the center of NGC 2784 until it flattens beyond a radius of 0.5 Mpc. We interpret the baseline density level to represent the background contamination and estimate that 22 of the 31 new candidates are dwarf members of the group. The candidate’s average color,

, and Sérsic structural parameters are consistent with those parameters for the dwarf populations of other groups. We find that the central population of dwarfs is redder and brighter than the rest of the population. The measured faint-end slope of the luminosity function,

, is steeper than that of the Local Group, but consistent with published results for other groups. Such comparisons are complicated by systematic differences among different studies, but will be simpler when the KMTNet survey, which will provide homogenous data for 15–20 groups, is completed.
Hydrogen-poor Superluminous Supernovae with Late-time Hα Emission: Three Events From the Intermediate Palomar Transient Factory
Authors: Yan Lin , Lunnan R. , Perley D. A. , Gal-Yam A. , Yaron O. , Roy R. , Quimby R. , Sollerman J. , Fremling C. , Leloudas G. , Cenko S. B. , Vreeswijk P. , Graham M. L. , Howell D. A. , Cia A. De , Ofek E. O. , Nugent P. , Kulkarni S. R. , Hosseinzadeh G. , Masci F. , McCully C. , Rebbapragada U. D. , Woźniak P.
Published: October 2017

We present observations of two new hydrogen-poor superluminous supernovae (SLSN-I), iPTF15esb and iPTF16bad, showing late-time Hα emission with line luminosities of

erg s−1 and velocity widths of (4000–6000) km s−1. Including the previously published iPTF13ehe, this makes up a total of three such events to date. iPTF13ehe is one of the most luminous and the slowest evolving SLSNe-I, whereas the other two are less luminous and fast decliners. We interpret this as a result of the ejecta running into a neutral H-shell located at a radius of ∼1016 cm. This implies that violent mass loss must have occurred several decades before the supernova explosion. Such a short time interval suggests that eruptive mass loss could be common shortly before core collapse, and more importantly helium is unlikely to be completely stripped off the progenitor and could be present in the ejecta. It is a mystery why helium features are not detected, even though nonthermal energy sources, capable of ionizing He, may exist as suggested by the O ii absorption series in the early-time spectra. Our late-time spectra (+240 days) appear to have intrinsically lower [O i] 6300 Å luminosities than that of SN2015bn and SN2007bi, which is possibly an indication of less oxygen (<10 M
⊙). The blueshifted Hα emission relative to the hosts for all three events may be in tension with the binary model proposed for iPTF13ehe. Finally, iPTF15esb has a peculiar light curve (LC) with three peaks separated from one another by ∼22 days. The LC undulation is stronger in bluer bands. One possible explanation is ejecta-circumstellar medium interaction.
The Transition of a Type IIL Supernova into a Supernova Remnant: Late-time Observations of SN 2013by
Authors: Black C. S. , Milisavljevic D. , Margutti R. , Fesen R. A. , Patnaude D. , Parker S.
Published: October 2017

We present early-time Swift and Chandra X-ray data along with late-time optical and near-infrared observations of SN 2013by, a Type IIL supernova (SN) that occurred in the nearby spiral galaxy ESO 138−G10 (D ∼ 14.8 Mpc). Optical and NIR photometry and spectroscopy follow the late-time evolution of the SN from days +89 to +457 post maximum brightness. The optical spectra and X-ray light curves are consistent with the picture of an SN having prolonged interaction with circumstellar material (CSM) that accelerates the transition from SN to supernova remnant (SNR). Specifically, we find SN 2013by’s Hα profile exhibits significant broadening (∼10,000 km s−1) on day +457, the likely consequence of high-velocity, H-rich material being excited by a reverse shock. A relatively flat X-ray light curve is observed that cannot be modeled using Inverse Compton scattering processes alone, but requires an additional energy source most likely originating from the SN-CSM interaction. In addition, we see the first overtone of CO emission near 2.3 μm on day +152, signaling the formation of molecules and dust in the SN ejecta and is the first time CO has been detected in a Type IIL SN. We compare SN 2013by with Type IIP SNe, whose spectra show the rarely observed SN-to-SNR transition in varying degrees and conclude that Type IIL SNe may enter the remnant phase at earlier epochs than their Type IIP counterparts.
Timing Analysis of V404 Cyg during Its Brightest Outburst with INTEGRAL/SPI
Authors: Rodi J. , Jourdain E. , Roques J. P.
Published: October 2017

The outburst of V404 Cyg during the summer of 2015 reached unparalleled intensities at X-ray and soft gamma-ray energies with fluxes

Crab in the 20–50 keV energy band. To date, studies in the hard X-ray/soft gamma-ray energy domain have focused primarily on the energy spectra. In this work, a timing analysis has been performed with INTEGRAL/SPI data in the 20–300 keV energy range for INTEGRAL revolution 1557, which corresponds to the brightest flare of V404 Cyg (on 2015 June 26). The power spectra are fit with broken power-law and multi-Lorentzian models and compared with previously reported results of V404 Cyg flaring activity from 1989 and 2015. Also, we took advantage of the good signal-to-noise ratio obtained above 70 keV to quantify the timing/fast-variability properties of the source as a function of energy. We then point out similarities of V404 Cyg with the black hole transient V4641 Sgr. Like V4641 Sgr, we found that the power spectra of V404 Cyg during high flux periods did not possess the expected flat-top feature typically seen in a hard spectral state. Interpretations are proposed in the framework of the fluctuating-propagation model to explain the observed properties.
Astrophysical Implications of a New Dynamical Mass for the Nearby White Dwarf 40 Eridani B
Authors: Bond Howard E. , Bergeron P. , Bédard A.
Published: October 2017

The bright, nearby DA-type white dwarf (WD) 40 Eridani B is orbited by the M dwarf 40 Eri C, allowing determination of the WD’s mass. Until recently, however, the mass depended on orbital elements determined four decades ago, and that mass was so low that it created several astrophysical puzzles. Using new astrometric measurements, the binary-star group at the U.S. Naval Observatory has revised the dynamical mass upward, to 0.573 ± 0.018 M
☉. In this paper, we use model-atmosphere analysis to update other parameters of the WD, including effective temperature, surface gravity, radius, and luminosity. We then compare these results with WD interior models. Within the observational uncertainties, theoretical cooling tracks for CO-core WDs of its measured mass are consistent with the position of 40 Eri B in the H-R diagram; equivalently, the theoretical mass–radius relation (MRR) is consistent with the star’s location in the mass–radius plane. This consistency is, however, achieved only if we assume a “thin” outer hydrogen layer, with q
H = M
H/M
WD ≃ 10−10. We discuss other evidence that a significant fraction of DA WDs have such thin H layers, in spite of the expectation from canonical stellar-evolution theory of “thick” H layers with q
H ≃ 10−4. The cooling age of 40 Eri B is ∼122 Myr, and its total age is ∼1.8 Gyr. We present the MRRs for 40 Eri B and three other nearby WDs in visual binaries with precise mass determinations, and show that the agreement of current theory with observations is excellent in all cases.
Sensitivity to Thermonuclear Reaction Rates in Modeling the Abundance Anomalies of NGC 2419
Authors: Dermigny J. R. , Iliadis C.
Published: October 2017

Abundance anomalies in globular clusters provide strong evidence for multiple stellar populations within each cluster. These populations are usually interpreted as distinct generations, with the currently observed second-generation stars having formed in part from the ejecta of massive, first-generation “polluter” stars, giving rise to the anomalous abundance patterns. The precise nature of the polluters and their enrichment mechanism are still unclear. Even so, the chemical abundances measured in second-generation stars within the globular cluster NGC 2419 provide insight into this puzzling process. Previous work used Monte Carlo nuclear reaction network calculations to constrain the temperature–density conditions that could reproduce the observed abundances, thereby placing robust limits on the origins of the polluter material. The effect of individual reaction rates on these conditions has not been studied, however. Thus, we perform an exhaustive sensitivity study on the nuclear physics input to determine which reactions have the greatest impact on these predictions. We find that the

Si(p,γ)

P,

Ar(p,γ)

K,

Ar(p,γ)

K, and

K(p,γ)

Ca reactions are all critical in determining the temperature–density conditions, and ultimately, the origins of the polluter material. We conclude with recommendations for future experiments.
Fragmentation of a Filamentary Cloud Permeated by a Perpendicular Magnetic Field
Authors: Hanawa Tomoyuki , Kudoh Takahiro , Tomisaka Kohji
Published: October 2017

We examine the linear stability of an isothermal filamentary cloud permeated by a perpendicular magnetic field. Our model cloud is assumed to be supported by gas pressure against self-gravity in the unperturbed state. For simplicity, the density distribution is assumed to be symmetric around the axis. Also for simplicity, the initial magnetic field is assumed to be uniform, and turbulence is not taken into account. The perturbation equation is formulated to be an eigenvalue problem. The growth rate is obtained as a function of the wavenumber for fragmentation along the axis and the magnetic field strength. The growth rate depends critically on the outer boundary. If the displacement vanishes in regions very far from the cloud axis (fixed boundary), cloud fragmentation is suppressed by a moderate magnetic field, which means the plasma beta is below 1.67 on the cloud axis. If the displacement is constant along the magnetic field in regions very far from the cloud, the cloud is unstable even when the magnetic field is infinitely strong. The cloud is deformed by circulation in the plane perpendicular to the magnetic field. The unstable mode is not likely to induce dynamical collapse, since it is excited even when the whole cloud is magnetically subcritical. For both boundary conditions, the magnetic field increases the wavelength of the most unstable mode. We find that the magnetic force suppresses compression perpendicular to the magnetic field especially in regions of low density.
Partial Accretion in the Propeller Stage of Low-mass X-Ray Binary Aql X–1
Authors: Güngör C. , Ekşi˙ K. Y. , Göğüş E. , Güver T.
Published: October 2017

Aql X–1 is one of the most prolific low-mass X-ray binary transients (LMXBTs) showing outbursts almost annually. We present the results of our spectral analyses of Rossi X-Ray Timing Explorer/proportional counter-array observations of the 2000 and 2011 outbursts. We investigate the spectral changes related to the changing disk-magnetosphere interaction modes of Aql X–1. The X-ray light curves of the outbursts of LMXBTs typically show phases of fast rise and exponential decay. The decay phase shows a “knee” where the flux goes from the slow-decay to the rapid-decay stage. We assume that the rapid decay corresponds to a weak propeller stage at which a fraction of the inflowing matter in the disk accretes onto the star. We introduce a novel method for inferring, from the light curve, the fraction of the inflowing matter in the disk that accretes onto the neutron star depending on the fastness parameter. We determine the fastness parameter range within which the transition from the accretion to the partial propeller stage is realized. This fastness parameter range is a measure of the scale height of the disk in units of the inner disk radius. We applied the method to a sample of outbursts of Aql X–1 with different maximum flux and duration times. We show that different outbursts with different maximum luminosity and duration follow a similar path in the parameter space of accreted/inflowing mass flux fraction versus fastness parameter.
A New Fokker–Planck Approach for the Relaxation-driven Evolution of Galactic Nuclei
Authors: Vasiliev Eugene
Published: October 2017

We present an approach for simulating the collisional evolution of spherical isotropic stellar systems based on the one-dimensional Fokker–Planck equation. A novel aspect is that we use the phase volume as the argument of the distribution function instead of the traditionally used energy, which facilitates the solution. The publicly available code PhaseFlow implements a high-accuracy finite-element method for the Fokker–Planck equation, and can handle multiple-component systems, optionally with the central black hole and taking into account loss-cone effects and star formation. We discuss the energy balance in the general setting, and in application to the Bahcall–Wolf cusp around a central black hole, for which we derive a perturbative solution. We stress that the cusp is not a steady-state structure, but rather evolves in amplitude while retaining an approximately

density profile. Finally, we apply the method to the nuclear star cluster of the milky Way, and illustrate a possible evolutionary scenario in which a two-component system of lighter main-sequence stars and stellar-mass black holes develops a Bahcall–Wolf cusp in the heavier component and a weaker

cusp in the lighter, visible component, over the period of several Gyr. The present-day density profile is consistent with the recently detected mild cusp inside the central parsec, and is weakly sensitive to initial conditions.
Dépendance, refus de la différence
Authors: Rezende Cardoso Marta
Published: October 2017

La dépendance psychique pendant l’adolescence est ici traitée sous deux angles : la relation Moi/autre et la polarité intériorité/extériorité. Dans ce passage de l’enfance à l’âge adulte, l’expérience de séparation de l’objet est le versant central de la question de la dépendance, particulièrement dans les addictions. Nous voulons montrer le caractère paradoxal du processus de séparation à l’adolescence, son noyau primaire et œdipien dans l’imbrication desquels se situe le fondement de ses impasses.
Le travail psychique d’identité
Authors: Bilbao Alejandro , Jofré Daniel
Published: October 2017

Au travers d’une réflexion concernant le travail identitaire et de transmission psychique entre les générations, cet article se penche attentivement sur le rapport que ces deux dimensions entretiennent pour une compréhension des modes de subjectivation psychique en prenant le paradigme de la filiation comme un élément central.
Le silence et le mot surprise
Authors: Benyamin Mickael , Pirlot Gérard
Published: October 2017

Les auteurs, à partir d’une vignette clinique, se proposent de revisiter le silence et l’inhibition du fonctionnement psychique chez les adolescents. Ils s’appuient sur le travail du préconscient dont le rôle est majeur dans le traitement des excitations et de la génitalité propre au processus de l’adolescence et tentent de l’articuler avec une théorie de la technique avec les adolescents.
Nos morts sont extraordinaires. Personnalisation des panthéons et récits hagiographiques au Brésil
Authors: Rougeon Marina
Published: October 2017

À partir d’une ethnographie menée dans une ville du Centre-Ouest brésilien (Goiás), cet article propose d’explorer les résonnances entre les récits de vies ordinaires des habitants et des bénisseurs, et les récits de vies extraordinaires qu’ils énoncent au sujet de certains de leurs morts et de saints catholiques, considérés comme médiateurs entre les hommes et le divin. Ces résonnances indiquent comment s’installe une familiarité entre les humains et des entités spirituelles appartenant à différents panthéons religieux (catholicisme, spiritisme, umbanda) ou à aucun. Elles révèlent une logique de réappropriation et de personnalisation des panthéons non exclusive aux bénisseurs, qui établit des appartenances communes entre humains et entités et permet aux vivants de se situer dans le jeu quotidien des rapports sociaux, notamment dans leur dimension interraciale. L’établissement de généalogies spirituelles et de valeurs socialement partagées, les enjeux mémoriels liés au passé esclavagiste ainsi que la mise à l’épreuve des récits hagiographiques reconnus par l’Église catholique, seront interrogés à travers une analyse de la production de ces entrelacs narratifs dans un univers religieux non institutionnalisé.
Entomological citizen science in Canada
Authors: Acorn John H.
Published: October 2017

Citizen science involves voluntary participation in the scientific process, typically by gathering data in order to monitor some aspect of the natural world. Entomological citizen science, as an extension of traditional amateur entomology, is an active field in Canada, with online databases such as eButterfly and BugGuide attracting both contributors and database users. As well, traditional amateur entomology continues to be important in Canada, as do short-term insect-themed educational events, the involvement of amateurs in entomological societies, and online crowdsourcing initiatives. Success of citizen science projects can be measured in many ways. In terms of published papers that analyse trends in citizen science data, Canadian projects have only begun to deliver. More valuable are particular records that improve our knowledge of geographic ranges and phenology. In terms of the endurance of particular projects, and the willingness of volunteers to participate, citizen science entomology in Canada is clearly a success. However, quality control of citizen science data remains an issue for some projects. As well, challenges remain with respect to balancing the goals of researchers, participants, and supporting institutions.
Aryl Hydrocarbon Receptor Activation Suppresses EBF1 and PAX5 and Impairs Human B Lymphopoiesis
Authors: Li Jinpeng , Bhattacharya Sudin , Zhou Jiajun , Phadnis-Moghe Ashwini S. , Crawford Robert B. , Kaminski Norbert E.
Published: October 2017

Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates biological responses to endogenous and environmental chemical cues. Increasing evidence shows that the AHR plays physiological roles in regulating development, homeostasis, and function of a variety of cell lineages in the immune system. However, the role of AHR in human B cell development has not been investigated. Toward this end, an in vitro feeder-free human B cell developmental model system was employed using human cord blood CD34+ hematopoietic stem/progenitor cells. Using this model, we found that AHR activation by the high-affinity ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin significantly suppressed the generation of early B cells and pro-B cells from hematopoietic stem/progenitor cells, indicating the impairment of B cell lineage specification and commitment. Addition of an AHR antagonist reversed 2,3,7,8-tetrachlorodibenzo-p-dioxin–elicited suppression of early B and pro-B cells, suggesting a role of AHR in regulating B lymphopoiesis. Gene expression analysis revealed a significant decrease in the messenger RNA level of early B cell factor 1 (EBF1) and paired box 5, two critical transcription factors directing B cell lineage specification and commitment. Additionally, binding of the ligand-activated AHR to the putative dioxin response elements in the EBF1 promoter was demonstrated by EMSAs and chromatin immunoprecipitation analysis, suggesting transcriptional regulation of EBF1 by AHR. Taken together, this study demonstrates a role for the AHR in regulating human B cell development, and it suggests that transcriptional alterations of EBF1 by the AHR are involved in the underlying mechanism.
Rab27-Dependent Exosome Production Inhibits Chronic Inflammation and Enables Acute Responses to Inflammatory Stimuli
Authors: Alexander Margaret , Ramstead Andrew G. , Bauer Kaylyn M. , Lee Soh-Hyun , Runtsch Marah C. , Wallace Jared , Huffaker Thomas B. , Larsen Dane K. , Tolmachova Tanya , Seabra Miguel C. , Round June L. , Ward Diane M. , O’Connell Ryan M.
Published: October 2017

Extracellular vesicles, including exosomes, have recently been implicated as novel mediators of immune cell communication in mammals. However, roles for endogenously produced exosomes in regulating immune cell functions in vivo are just beginning to be identified. In this article, we demonstrate that Rab27a and Rab27b double-knockout (Rab27DKO) mice that are deficient in exosome secretion have a chronic, low-grade inflammatory phenotype characterized by elevated inflammatory cytokines and myeloproliferation. Upon further investigation, we found that some of these phenotypes could be complemented by wild-type (WT) hematopoietic cells or administration of exosomes produced by GM-CSF–expanded bone marrow cells. In addition, chronically inflamed Rab27DKO mice had a blunted response to bacterial LPS, resembling endotoxin tolerance. This defect was rescued by bone marrow exosomes from WT, but not miR-155−/−, cells, suggesting that uptake of miR-155–containing exosomes is important for a proper LPS response. Further, we found that SHIP1 and IRAK-M, direct targets of miR-155 that are known negative regulators of the LPS response, were elevated in Rab27DKO mice and decreased after treatment with WT, but not miR-155−/−, exosomes. Together, our study finds that Rab27-dependent exosome production contributes to homeostasis within the hematopoietic system and appropriate responsiveness to inflammatory stimuli.
Does Chicago Classification address Symptom Correlation with High-resolution Esophageal Manometry?
Authors: Srinivas Melpakkam , Bawane Piyush
Published: October 2017

Aim

To assess the correlation of symptoms with findings on esophageal high-resolution manometry (HRM) in Indian patients.

Materials and methods

Prospective data collection of all patients undergoing esophageal manometry was done at two centers in India—Indore and Chennai—over a period of 18 months. Symptom profile of the study group was divided into four: Motor dysphagia, noncardiac chest pain (NCCP), gastroesophageal reflux (GER), and esophageal belchers. The symptoms were correlated with manometric findings.

Results

Of the study group (154), 35.71% patients had a normal study, while major and minor peristaltic disorders were noted in 31.16 and 33.76% respectively. In patients with symptoms of dysphagia, achalasia cardia was the commonest cause (45.1%), followed by ineffective esophageal motility (IEM) (22.53%) and normal study (19.71%). In patients with NCCP, normal peristalsis (50%) and ineffective motility (31.25%) formed the major diagnosis. Of the 56 patients with GER symptoms, 26 (46.4%) had normal manometry. An equal number had ineffective motility. Of the 11 esophageal belchers, 7 (63.6%) of these had a normal study and 3 had major motility disorder. Dysphagia was the only symptom to have a high likelihood ratio and positive predictive value to pick up major motility disorder.

Conclusion

Dysphagia correlates with high chance to pick up a major peristaltic abnormality in motor dysphagia. The role of manometry in other symptoms in Indian setting needs to be ascertained by larger studies.

Clinical significance

The present study highlights lack of symptom correlation with manometry findings in Indian patients.

How to cite this article

Jain M, Srinivas M, Bawane P, Venkataraman J. Does Chicago Classification address Symptom Correlation with High-resolution Esophageal Manometry? Euroasian J Hepato-Gastroenterol 2017;7(2):122-125.
Pneumatic Balloon Dilatation for Achalasia Cardia: Outcome, Complications, Success, and Long-term Follow-up
Authors: Gupta Sudhir J , Gaikwad Nitin R , Samarth Amol R , Gattewar Sonal R
Published: October 2017

Background

Achalasia is a chronic disease that can be managed with effective endoscopic modalities.

Aim

To evaluate the effectiveness of single setting of pneumatic balloon dilatation for achalasia and assess the long-term success and outcomes.

Materials and methods

This is a retrospective study of all achalasia patients who underwent pneumatic balloon dilatation at our institute. Patients who could be contacted were inquired regarding their symptoms and dysphagia-free interval after dilatation.

Results

A total of 72 patients were enrolled. Out of this, 14 patients lost to follow-up. Mean age of 58 patients was 45.02 ± 16.51 years. Male:female ratio was 13:16. Mean predilatation Eckardt score was 7.16 ± 0.834. Type I achalasia was present in 10 (17.2%), type II in 44 (75.9%), type III in 4 (6.9%). Predilatation basal integrated relaxation pressure (IRP) was 28.14 ± 14.76 mm Hg. Postdilatation Eckardt score was 2.40 ± 1.67. Postdilatation dysphagia-free interval was 17.28 ± 6.70 months. A total of 9 patients (15.51%) failed to respond to first dilatation and 49 (84.48%) patients benefited from single setting of pneumatic dilatation. Esophageal perforation occurred in 2/58 (3.44%). We did not find any significant difference in gender distribution, age of presentation, duration of symptom, pre- and postdilatation Eckardt score, type of achalasia, and basal IRP on manometry between type of achalasia. Postdilatation dysphagia-free interval in type II achalasia (18.09 ± 5.976 months) was more than types I and III achalasia cardia (p = 0.066), which showed trend toward significance.

Conclusion

Pneumatic balloon dilatation of achalasia cardia is a highly effective endoscopic procedure with minimal complications and mortality. Even the single setting of dilatation can have long-lasting dysphagia-free interval.

How to cite this article

Gupta SJ, Gaikwad NR, Samarth AR, Gattewar SR. Pneumatic Balloon Dilatation for Achalasia Cardia: Outcome, Complications, Success, and Long-term Follow-up. Euroasian J Hepato-Gastroenterol 2017;7(2):138-141.
Effect of Different Sedation Regimes on Cognitive Functions in Colonoscopy
Authors: Ekmekçi Perihan , Erkan Gulbanu , Kazbek Baturay K , Köksoy Ulku C , Doganay Güler , Tüzüner Filiz
Published: October 2017

Aim

To compare the effects of propofol/remifentanil and meperidine/midazolam on postprocedure cognitive function.

Materials and methods

A total of 100 American Society of Anesthesiologists (ASA) score I to III patients undergoing elective colonoscopy were taken into the study and divided into two groups. Exclusion criteria were patient refusal, mini mental test (MMT) <26, The Amsterdam Preoperative Anxiety and Information Scale (APAIS) >10, advanced cardiopulmonary or psychiatric disease, chronic alcohol abuse, morbid obesity, and known allergy to study drugs. In group MM, 2 mg midazolam and 20 mg meperidine was given intravenously and additional 1 to 2 mg midazolam and 20 mg meperidine (with a maximum total of 5 mg midazolam and 50 mg meperidine) was given when bispectral index (BIS) was >80. In group RP, 100 μg/kg/minute propofol infusion and 1 μg/kg remifentanil bolus was administered and additional 0.5 μg/kg remifentanil bolus was given when BIS was >80. Observer's Assessment of Alertness/Sedation scale (OAA/S) and Facial Pain Score (FPS) values were recorded. Cognitive function was measured by Trieger Dot Test (TDT) and Digit Symbol Substitution Test (DSST).

Results

The study was concluded with 100 patients. Heart rate was slower and BIS values were lower in group RP throughout the procedure. Blood pressure was lower in group RP without clinical significance. There was no difference concerning recovery time and visual analog scores (VASs). In group MM, TDT scores were higher and DSST scores were lower. Satisfaction was higher in group RP.

Conclusion

Propofol/remifentanil combination is better than meperidine/midazolam combination concerning cognitive function in sedation for colonoscopy.

Clinical significance

The addition of BIS monitorization to evaluate the depth of sedation and the negative effects of midazolam meperidine combination on postprocedural cognitive function.

How to cite this article

Ekmekçi P, Erkan G, Yilmaz H, Kazbek BK, Köksoy UC, Doganay G, Tüzüner F. Effect of Different Sedation Regimes on Cognitive Functions in Colonoscopy. Euroasian J Hepato-Gastroenterol 2017;7(2):158-162.
Massive Lower Gastrointestinal Bleed caused by Typhoid Ulcer: Conservative Management
Authors: Goel Apoorv , Bansal Roli
Published: October 2017

Typhoid fever is caused by gram-negative organism Salmonella typhi. The usual presentation is high-grade fever, but complications like gastrointestinal (GI) hemorrhage and perforation are also seen frequently. With the advent of antibiotics, these complications are rarely seen now. We present a case of a young female who was admitted with a diagnosis of typhoid fever presented with a massive GI bleed from ulcers in the terminal ileum and was managed conservatively without endotherapy and surgery.

How to cite this article

Goel A, Bansal R. Massive Lower Gastrointestinal Bleed caused by Typhoid Ulcer: Conservative Management. Euroasian J Hepato-Gastroenterol 2017;7(2):176-177.
A Rare Case of Complete Agenesis of Dorsal Pancreas
Authors: Dey Subhajeet , Singh Malwinder , Kaura Ankit , Diwakar Gaurav
Published: October 2017

Agenesis of dorsal pancreas (ADP) is an extremely rare congenital anomaly that results from defective development of pancreas. Most ADP patients are asymptomatic; if symptomatic, they present with epigastric pain. About half of affected individuals develop diabetes mellitus (DM), resulting from reduced islet cell mass secondary to the absence of endocrine structures. Being very rare, it is generally not kept in mind while dealing these cases and are not suspected until imaging investigations are not done. In our case study, ADP was diagnosed during evaluation of the patient for recurrent pain abdomen and generalized weakness.

How to cite this article

Jain A, Singh M, Dey S, Kaura A, Diwakar G. A Rare Case of Complete Agenesis of Dorsal Pancreas. Euroasian J Hepato-Gastroenterol 2017;7(2):183-184.
Ascitic Fluid/Serum Bilirubin Ratio as an aid in Preoperative Diagnosis of Choleperitoneum in a Neglected Case of Spontaneous Common Bile Duct Perforation
Authors: Huda Farhanul , Singh Sudhir K , Saha Sarama
Published: October 2017

Spontaneous perforation of extrahepatic biliary system is a rare and potentially fatal cause of acute abdomen. Clinical presentation is as biliary peritonitis. This condition is rarely suspected as a cause of peritonitis preoperatively and correct diagnosis is made during surgery. If suspected, diagnosis can be made by various imaging techniques like hepatobiliary scintigraphy, magnetic resonance cholangiopancreatography (MRCP), and endoscopic retrograde cholangiopancreatography (ERCP). As these imaging techniques are not readily available, especially in low socioeconomic countries, we hereby report a case of spontaneous common bile duct (CBD) perforation, which was diagnosed preoperatively by estimation of ascitic fluid-to-serum bilirubin ratio, a simple, quick, and cost-effective test.

How to cite this article

Huda F, Naithani M, Singh SK, Saha S. Ascitic Fluid/Serum Bilirubin Ratio as an aid in Preoperative Diagnosis of Choleperitoneum in a Neglected Case of Spontaneous Common Bile Duct Perforation. Euroasian J Hepato-Gastroenterol 2017;7(2):185-187.
Handwriting and Common Core State Standards: Teacher, Occupational Therapist, and Administrator Perceptions From New York State Public Schools
Authors: Collette Debra , Anson Kylie , Halabi Nora , Schlierman April , Suriner Allison
Published: October 2017

Handwriting is the cornerstone of written performance and communication for school-age children. This mixed-methods study explored the impact of Common Core State Standards on handwriting instruction and its effects on perceptions regarding children’s written responses in elementary school. Using surveys and interviews of elementary teachers, occupational therapists, and administrators in New York State public schools, we sought to understand current trends in handwriting instruction, changes in time spent on handwriting instruction in the classroom, supports offered to students who did not meet expectations for handwriting, and the impact of Common Core on children’s written expression. Themes emerged revealing decreased handwriting instruction time and inconsistent use of handwriting instructional programs in the classroom after implementation of Common Core. Handwriting should be considered as a greater component in the foundational standards in Common Core. Occupational therapy services can support handwriting instruction implementation.
Le Musée du bagne en Nouvelle-Calédonie et ses constructions identitaires / The Penal Colony Museum in New Caledonia and its Identity Constructions
Authors: Pascual Fanny Cécile
Published: October 2017

In the South Pacific, New Caledonia and Australia were penal colonies during the 19th century. Analysing the discourse surrouding two museums based on these convict periods (Hyde Park Barracks in Sydney and the project for a museum in Noumea), will shed light on the difficulties of facing this violent past. Even if these two countries and their histories are different, they have a common aim to accept this part of their genealogies. After having been taboo, having criminal ancestors is now a pride; exile is no more seen as an expulsion from the English or French motherland, but has become a pioneer adventure. Suppressing some aspects of this colonisation and downplaying the participation or the interactions of convicts or bagnards with other communities helps to build this memory. We must also keep in mind that museums have a political role. In New Caledonia, it is obvious that the self-determination process between 2014 and 2018 has influenced the project of the museum in Nouville: having a convict in the family will prove your belonging to the land and could justify voting rights for the 2018 referendum. These museums accordingly do not only deal with history, but influence the future.

Au XIXème siècle, la Nouvelle-Calédonie et l'Australie étaient des colonies pénitentiaires dans le Pacifique Sud. L’analyse du discours muséal des deux musées (Hyde Park Barracks à Sydney et le projet pour un musée du bagne à Nouméa) se base sur la période pénitentiaire pour mettre en lumière les difficultés que l’on peut avoir à affronter son passé de violence. Même si ces deux pays ont une histoire différente, le but commun est d'accepter cette partie de leur généalogie. Après avoir été tabou, avoir des ancêtres criminels est maintenant une source de fierté; l'exil n'est plus considéré comme une expulsion de la patrie britannique ou française, mais plutôt comme une aventure de pionniers. Ceci entraîne un déni d'autres aspects de la colonisation et réduit la participation ou les interactions entre communautés dans la construction de l’histoire mémorielle. Nous devons également garder à l'esprit que les musées jouent un rôle politique. En Nouvelle-Calédonie, il est évident que le processus d'autodétermination prévu entre 2014-2018 a influencé le projet du musée à Nouville. Un bagnard dans la famille prouvera votre ancrage dans cette terre et pourrait justifier votre droit de vote dans le référendum. Ces musées n’évoquent pas seulement l'histoire mais préparent aussi l’avenir.
Sustainability: Suspicions Concerning Attainability, with Particular Reference to the Pacific
Authors: Wolfers Edward
Published: October 2017

Sustainability and unsustainability are frequently deployed in discussions of intended, predicted and observed changes occurring in or impacting on Pacific islands societies. Local communities often have their own distinctive understanding of the natural environment. Their concern for sustainability frequently extends further afield – to languages, cultures, and other aspects of life. International agreements and the constitutions of a number of Pacific islands countries address relevant issues. Constitutional government in the region has been remarkably sustained. Sustainable development has diverse dimensions and can be controversial. Climate change and rising sea-levels threaten the very survival of low-lying islands. Harvesting of non-renewable resources raises particular issues. Pacific islands studies have made significant contributions to scientific knowledge and human understanding of issues and processes of wider, even global importance.
My Brother the Mexican
Authors: Dwyer K. Angelique
Published: October 2017

El “Piti” le decían, I never knew why. We lived just outside “El Barrio,” at least that’s what they called it, ‘cause it took too long to say “Tlachichilco del Carmen.” Nobody called it that, but my mom. She would make us go to El Barrio a vender “panquecitos.” Two little gringüitos selling cupcakes en la plaza.

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The impact of uncertainty on optimal emission policies
Authors: Botta Nicola , Jansson Patrik , Ionescu Cezar
Published: October 2017

Abstract. We apply a computational framework for specifying and solving sequential decision problems to study the impact of three kinds of uncertainties on optimal emission policies in a stylized sequential emission problem. We find that uncertainties about the implementability of decisions on emission reductions (or increases) have a greater impact on optimal policies than uncertainties about the availability of effective emission reduction technologies and uncertainties about the implications of trespassing critical cumulated emission thresholds. The results show that uncertainties about the implementability of decisions on emission reductions (or increases) call for more precautionary policies. In other words, delaying emission reductions to the point in time when effective technologies will become available is sub-optimal when these uncertainties are accounted for rigorously. By contrast, uncertainties about the implications of exceeding critical cumulated emission thresholds tend to make early emission reductions less rewarding.