bluuebunny/crossref_metadata_2025 huggingface dataset:
Gastrointestinal toxicity among patients taking selective COX‐2 inhibitors or conventional NSAIDs, alone or combined with proton pump inhibitors: a case–control study
Authors: Bakhriansyah Mohammad , Souverein Patrick C. , de Boer Anthonius , Klungel Olaf H.
Published: March 2017

Purpose

To assess the risk of gastrointestinal perforation, ulcers, or bleeding (PUB) associated with the use of conventional nonsteroidal anti‐inflammatory drugs (NSAIDs) with proton pump inhibitors (PPIs) and selective COX‐2 inhibitors, with or without PPIs compared with conventional NSAIDs.

Methods

A case–control study was performed within conventional NSAIDs and/or selective COX‐2 inhibitors users identified from the Dutch PHARMO Record Linkage System in the period 1998–2012. Cases were patients aged ≥18 years with a first hospital admission for PUB. For each case, up to four controls were matched for age and sex at the date a case was hospitalized (index date). Logistic regression analysis was used to calculate odds ratios (ORs).

Results

At the index date, 2634 cases and 5074 controls were current users of conventional NSAIDs or selective COX‐2 inhibitors. Compared with conventional NSAIDs, selective COX‐2 inhibitors with PPIs had the lowest risk of PUB (adjusted OR 0.51, 95% confidence interval [CI]: 0.35–0.73) followed by selective COX‐2 inhibitors (adjusted OR 0.66, 95%CI: 0.48–0.89) and conventional NSAIDs with PPIs (adjusted OR 0.79, 95%CI: 0.68–0.92). Compared with conventional NSAIDs, the risk of PUB was lower for those aged ≥75 years taking conventional NSAIDs with PPIs compared with younger patients (adjusted interaction OR 0.79, 95%CI: 0.64–0.99). However, those aged ≥75 years taking selective COX‐2 inhibitors, the risk was higher compared with younger patients (adjusted interaction OR 1.22, 95%CI: 1.01–1.47).

Conclusions

Selective COX‐2 inhibitors with PPIs, selective COX‐2 inhibitors, and conventional NSAIDs with PPIs were associated with lower risks of PUB compared with conventional NSAIDs. These effects were modified by age. © 2017 The Authors. Pharmacoepidemiology & Drug Safety Published by John Wiley & Sons Ltd.
The same batch enabled threshold voltage tuning for vertically‐ or laterally‐gated transparent InZnO thin‐film transistors
Authors: Zhang Lili , Li Long , Zhang Hongliang , Cao Hongtao , Liang Lingyan , Gao Junhua , Zhuge Fei , Zhou Jumei
Published: March 2017

Fully transparent InZnO thin‐film transistors (TFTs), with either a bottom gate or an in‐plane gate device structure, were fabricated using the solution‐processed SA proton conducting films as gate dielectrics. The self‐assembled InZnO channel with different thickness by the gradient shadow mask was fabricated during the same batch radio‐frequency magnetron sputtering. The threshold voltage can be modulated from −0.25 to +0.12 V and from −0.07 to +0.25 V by the channel layer thickness variations for the vertically‐coupled and laterally‐coupled InZnO TFTs, respectively. Accordingly, these InZnO TFTs can operate in either depletion or enhancement mode on the same chip. A general expression of the turn‐on voltage in relation to the channel thickness is derived. The device performance with an on/off current ratio of ≥1.5 × 106, a subthreshold swing of down to 70 mV/decade, and a field‐effect mobility of up to 34.3 cm2/V · s is exhibited. Our results demonstrate that the same batch channel processing is potentially applied in logic circuits or functional electronics.
Invariant digital image watermarking based on Defragmented Delaunay Triangulation for optimal watermark synchronization
Authors: Essaidani Dhekra , Seddik Hassene , Ben Braiek Ezzedine
Published: March 2017

Dramatic technology progress in data manipulation induced several attempts of baleful and illegal processing. In this regard, several protection techniques, including cryptography, steganography, and watermarking have been used to avoid the illegal production and distribution of data online. On the other side, the attacks are still a major problem that limits the effectiveness of watermarking techniques. The geometric attacks involve displacement of pixels. Therefore, they induce synchronization errors between the original and attacked image that complicates the watermark recovery process. So in order to solve the de‐synchronization problem, we propose to use a robust meshing technique between different geometrical data of the image to correct the geometric distortion. In this work, we propose a novel geometrically invariant digital image watermarking approach based on the geometrical feature of the cover image and the Defragmented Delaunay Triangulation on respecting the three constraints of watermarking approaches (imperceptibility of embedded watermark, embedding capacity, and robustness). The aim idea of this work is to propose a blind, imperceptible, and robust digital image watermarking scheme based on Defragmented Delaunay Tessellation and Weber's law. The defragmented triangulation provides a best synchronization of the embedded data after attacks application. The Weber's law is used to propose an auto‐thresholding algorithm to compute the optimal embedding gain factor for each watermark's bit in order to ensure the imperceptibility of the hidden data. Firstly, the invariant features in the host gray scale image are extracted by using the canny edge detector. Then, the Delaunay tessellation of the saved keys points set is generated and defragmented to select the optimal robust triangles for watermark embedding. Simulation results illustrate the imperceptibility of the embedded data and the robustness of the proposed approach against intentional and unintentional geometrical attacks are presented in the finally section. Copyright © 2017 John Wiley & Sons, Ltd.
Cost‐effectiveness of diagnostic testing strategies including cervical‐length measurement and fibronectin testing in women with symptoms of preterm labor
Authors: van Baaren G.‐J. , Vis J. Y. , Wilms F. F. , Oudijk M. A. , Kwee A. , Porath M. M. , Scheepers H. C. J. , Spaanderman M. E. A. , Bloemenkamp K. W. M. , Haak M. C. , Bax C. J. , Cornette J. M. J. , Duvekot J. J. , Nij Bijvanck B. W. A. , van Eyck J. , Franssen M. T. M. , Sollie K. M. , Vandenbussche F. P. H. A. , Woiski M. , Bolte A. C. , van der Post J. A. M. , Bossuyt P. M. M. , Opmeer B. C. , Mol B. W. J.
Published: March 2017

Objective

To evaluate the cost‐effectiveness of combining cervical‐length (CL) measurement and fetal fibronectin (fFN) testing in women with symptoms of preterm labor between 24 and 34 weeks' gestation.

Methods

This was a model‐based cost‐effectiveness analysis evaluating seven test–treatment strategies based on CL measurement and/or fFN testing in women with symptoms of preterm labor from a societal perspective, in which neonatal outcomes and costs were weighted. Estimates of disease prevalence, test accuracy and costs were based on two recently performed nationwide cohort studies in The Netherlands.

Results

Strategies using fFN testing and CL measurement separately to predict preterm delivery are associated with higher costs and incidence of adverse neonatal outcomes compared with strategies that combine both tests. Additional fFN testing when CL is 15–30 mm was considered cost effective, leading to a cost saving of €3919 per woman when compared with a treat‐all strategy, with a small deterioration in neonatal health outcomes, namely one additional perinatal death and 21 adverse outcomes per 10 000 women with signs of preterm labor (incremental cost‐effectiveness ratios €39 million and €1.9 million, respectively). Implementing this strategy in The Netherlands, a country with about 180 000 deliveries annually, could lead to an annual cost saving of between €2.4 million and €7.6 million, with only a small deterioration in neonatal health outcomes.

Conclusion

In women with symptoms of preterm labor at 24–34 weeks' gestation, performing additional fFN testing when CL is between 15 and 30 mm is a viable and cost‐saving strategy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
Prospective Evaluation of Predictive DNA Testing for Huntington's Disease in a Large German Center
Authors: Ibisler Aysegül , Ocklenburg Sebastian , Stemmler Susanne , Arning Larissa , Epplen Jörg T. , Saft Carsten , Hoffjan Sabine
Published: March 2017

We present a prospective study of counselees seeking predictive testing for Huntington's disease at the Huntington Center North Rhine‐Westphalia (Bochum, Germany) between 2010 and 2012. The aim was to observe the decision‐making process of at‐risk individuals and explore their experiences following the decision as well as the impacts of positive and negative mutation results. Data were collected using two standardized questionnaires as well as via a semi‐standardized telephone interview one year after the initial counseling session. Seventy‐two individuals participated in at least one of the three phases of the survey, including 31 individuals in the telephone interview. Sociodemographic data were in accordance with previous reports. The process of predictive testing was generally perceived in a positive manner, with almost all interviewees reporting a balanced emotional state one year after initial counseling, regardless of the decision for or against the test. The most important reasons named in favor of or against testing were assembled as well as different aspects regarding the satisfaction with the reached decision. In line with and expanding previous observations on gender‐related differences in decision‐making, our results suggest that gender‐related aspects should be more strongly taken into account in genetic counseling during the predictive testing and counseling processes.
Cognitive deficits associated with a high‐fat diet and insulin resistance are potentiated by overexpression of ecto‐nucleotide pyrophosphatase phosphodiesterase‐1
Authors: Kasper J.M. , Milton A.J. , Smith A.E. , Laezza F. , Taglialatela G. , Hommel J.D. , Abate N.
Published: March 2017

There is growing evidence that over consumption of high‐fat foods and insulin resistance may alter hippocampal‐dependent cognitive function. To study the individual contributions of diet and peripheral insulin resistance to learning and memory, we used a transgenic mouse line that overexpresses ecto‐nucleotide pyrophosphatase phosphodiesterase‐1 in adipocytes, which inhibits the insulin receptor. Here, we demonstrate that a model of peripheral insulin resistance exacerbates high‐fat diet induced deficits in performance on the Morris Water Maze task. This finding was then reviewed in the context of the greater literature to explore potential mechanisms including triglyceride storage, adiponectin, lipid composition, insulin signaling, oxidative stress, and hippocampal signaling. Together, these findings further our understanding of the complex relationship among peripheral insulin resistance, diet and memory.
Protestant Unity and Anti-Catholicism: The Irenicism and Philo-Semitism of John Dury in Context
Authors: Fradkin Jeremy
Published: March 2017

This article examines the religious and political worldview of the Scottish minister John Dury during the English Revolution of the mid-seventeenth century. It argues that Dury's activities as an irenicist and philo-semite must be understood as interrelated aspects of an expansionist Protestant cause that included Britain, Ireland, continental Europe, and the Atlantic world. Dury sought to imitate and counter what he perceived to be the principal strengths of early modern Catholicism: confessional unity, imperial expansion, and the coordination of global missionary efforts. The 1640s and 1650s saw the scope of Dury's long-standing vision grow to encompass colonial expansion in Ireland and America, where English and continental Protestants might work together to fortify their position against Spain and its growing Catholic empire. Both Portuguese Jews and American Indians appear in this vision as victims of Spanish Catholicism in desperate need of Protestant help. This article thus offers new perspectives on several aspects of Dury's career, including his relationship with displaced Anglo-Irish Protestants in London, his proposal to establish a college for the study of Jewish learning and “Oriental” languages, his speculation regarding the Lost Tribes of Israel in America, and his cautious advocacy for the toleration of Jews in England.
The Operatic Voice of Leoni the Jew: Between the Synagogue and the Theater in Late Georgian Britain
Authors: Erman Uri
Published: March 2017

Michael Leoni, a leading singer in late eighteenth-century London, became famous for his role in Richard Brinsley Sheridan's anti-Jewish operaThe Duenna. He was discovered, however, at the Jewish synagogue, where his singing enthralled non-Jews in the early 1770s. Tracing Leoni's public reception, this article argues that the performative effect of his singing had a multifaceted relation to his audience's psychology of prejudice, serving to both reiterate and reconfigure a variety of preconceptions regarding the Jews. Leoni's intervention through operatic singing was particularly significant––a powerful, bodily manifestation that was capable of transforming listeners while exhibiting the deep acculturation of the singer himself. The ambivalence triggered by his performances would go on to define the public reception of other Jewish singers, particularly that of Leoni's protégé, John Braham, Britain's leading tenor in the early nineteenth century. Ultimately, the experience of these Jews' performances could not be easily deconstructed, as the Jewish performers' voices were emanating from within written, sometimes canonical, musical works. This representational impasse gave rise to a public discourse intent on deciphering their Jewishness, raising questions of interpretation, intention, and confession.
Euler and Navier–Stokes equations in a new time-dependent helically symmetric system: derivation of the fundamental system and new conservation laws
Authors: Dierkes Dominik , Oberlack Martin
Published: March 2017

The present contribution is a significant extension of the work by Kelbin et al. (J. Fluid Mech., vol. 721, 2013, pp. 340–366) as a new time-dependent helical coordinate system has been introduced. For this, Lie symmetry methods have been employed such that the spatial dependence of the originally three independent variables is reduced by one and the remaining variables are: the cylindrical radius $r$ and the time-dependent helical variable $\unicode[STIX]{x1D709}=(z/\unicode[STIX]{x1D6FC}(t))+b\unicode[STIX]{x1D711}$, $b=\text{const.}$ and time $t$. The variables $z$ and $\unicode[STIX]{x1D711}$ are the usual cylindrical coordinates and $\unicode[STIX]{x1D6FC}(t)$ is an arbitrary function of time $t$. Assuming $\unicode[STIX]{x1D6FC}=\text{const.}$, we retain the classical helically symmetric case. Using this, and imposing helical invariance onto the equation of motion, leads to a helically symmetric system of Euler and Navier–Stokes equations with a time-dependent pitch $\unicode[STIX]{x1D6FC}(t)$, which may be varied arbitrarily and which is explicitly contained in all of the latter equations. This has been conducted both for primitive variables as well as for the vorticity formulation. Hence a significantly extended set of helically invariant flows may be considered, which may be altered by an external time-dependent strain along the axis of the helix. Finally, we sought new conservation laws which can be found from the helically invariant Euler and Navier–Stokes equations derived herein. Most of these new conservation laws are considerable extensions of existing conservation laws for helical flows at a constant pitch. Interestingly enough, certain classical conservation laws do not admit extensions in the new time-dependent coordinate system.
The Electronic Health Record and Patient Portals in HIV Medicine
Authors: DASKALAKIS DEMETRE C
Published: March 2017

The electronic medical record provides an exciting opportunity to support the coordination of care by medical and social providers. Many of these systems include patient portals that allow providers to share clinical information with patients in real time. These “patient portals” provide a unique opportunity for clients and patients to access and use HIV and sexually transmitted infection information for communication with healthcare providers, with potential or actual sex partners, and for tracking their own clinical course and progress. A concerted effort to develop these should include a high level of transparency and adequate support for both patient and provider.
Bioethicsing
Authors: ARAWI THALIA , MIKATI DIANA
Published: March 2017

This article describes the components of a unique 9 month required course in bioethics for 3rd year medical students at the American University of Beirut. The blended (hybrid) learning format emphasizes three innovative learning activities: the bioethics documentary, edutainment games, and the bioethics log book. Sample student responses are included as well as an outline of limitations.
Presidents, Baseball, and Wins above Expectations: What Can Sabermetrics Tell Us about Presidential Success?
Authors: Teodoro Manuel P. , Bond Jon R.
Published: March 2017

Presidential scholars and baseball writers debate who were the greatest. While baseball analysis evolved from qualitative impressions of “experts” to rigorous, data-driven “sabermetrics,” analysis of presidential greatness continues to rely on “old-school” reputational rankings based on surveys of scholars’ qualitative assessments. Presidential-congressional relations and baseball are all about winning, but what fans (of sports and politics) find most intriguing is Wins Above Expectations (WAE)—did the team do better or worse than expected? This paper adapts the Pythagorean Expectations (PE) formula developed to analyze baseball to assess legislative success of presidents from Eisenhower to Obama. A parsimonious regression model and the PE formula predict annual success rates with 90% accuracy. The estimates of WAE from the two approaches, however, are uncorrelated. Regression analysis does not identify any president who systematically exceeded expectations, but sabermetric analysis indicates that Republican presidents outperform Democrats. Neither approach correlates with recent presidential greatness rankings.
Gender Bias in International Relations Graduate Education? New Evidence from Syllabi
Authors: Colgan Jeff
Published: March 2017

Gender diversity is good for the study of international relations (IR) and political science. Graduate training is an opportunity for scholars to affect the demographics of their field and the gendered practices within it. This article presents a first-cut investigation of the degree to which gender bias exists in graduate IR syllabi. The author found that the gender of the instructor for graduate courses matters significantly for what type of research is taught, in two ways. First, on average, female instructors assign significantly more research by female authors than male instructors. Second, women appear to be considerably more reluctant than men about assigning their own research as required readings. Some but not all of the difference between male- and female-taught courses might be explained by differences in course composition.
Multilevel Bargaining and the Negotiation of a Regional Trade Agreement: A Classroom Simulation
Authors: Kerevel Yann P. , Hultquist Philip , Edwards Margaret E.
Published: March 2017

This article introduces a regional trade agreement (RTA) simulation for undergraduate students. The simulation uses a multilevel bargaining framework, in which students can represent not only governments of negotiating countries but also domestic interests. By allowing students to experience international bargaining at different levels, they gain a deeper understanding of controversial international trade processes.
Evidences of tidal distortion and mass loss from the old open cluster NGC 6791
Authors: Carraro Giovanni , Dalessandro Emanuele
Published: March 2017

We present the first evidence of clear signatures of tidal distortions in the density distribution of the fascinating open cluster NGC 6791. We find that the 2D density map shows a clear elongation and an irregular distribution starting from ~ 300″ from the cluster center and two tails extending in opposite directions beyond the tidal radius. These features are aligned to both the absolute proper motion and to the Galactic centre directions. Accordingly we find that both the surface brightness and star count density profiles reveal a departure from a King model starting from ~ 600″. These observational evidences suggest that NGC 6791 is currently undergoing mass-loss likely due to gravitational shocking and interactions with the tidal field of the Milky Way. We derive the expected mass-loss due to stellar evolution and tidal interactions and we estimate the initial cluster mass to be Mini = (1.5 − 4.0) × 105M⊙.
N131: A dust bubble was born from the disruption of a gas filament?
Authors: Zhang Chuan-Peng
Published: March 2017

N131 is an infrared dust bubble residing in a molecular filament. We aim to study the formation and fragmentation of this bubble with multi-wavelength dust and gas observations. Towards the bubble N131, we analyzed archival multi-wavelength observations including 3.6, 4.5, 5.8, 8.0, 24, 70, 160, 250, 350, 500 μm, 1.1 mm, and 21 cm. In addition, we performed new observations of CO (2-1), CO (1-0), and 13CO (1-0) with the IRAM 30-m telescope. Multi-wavelength dust and gas observations reveal a ringlike shell with compact fragments, two filamentary structures, and a secondary bubble N131-A. The bubble N131 is a rare object with a large hole at 24 μm and 21 cm in the direction of its center. The dust and gas clumps are compact and might have been compressed at the inner edge of the ringlike shell, while they are extended and might be pre-existing at the outer edge. The column density, excitation temperature, and velocity show a potentially hierarchical distribution from the inner to outer edge of the ringlike shell. We also detected the front and back sides of the secondary bubble N131-A in the direction of its center. The derived Lyman-continuum ionizing photon flux within N131-A is equivalent to an O9.5 star. Based on the above, we suggest that the bubble N131 might be triggered by the strong stellar winds from a group of massive stars inside the bubble. We propose a scenario in which the bubble N131 forms from the disruption of a gas filament by expansion of H II region, strong stellar winds, and fragments under self-gravity.
Globular Clusters within Dark Matter Halos: Case Studies of 47 Tuc, NGC 1851 and M 15
Authors: Lee Joowon , Shin Jihye , Kim Sungsoo S.
Published: March 2017

Globular clusters (GCs) are known to have a very small amount of or no dark matter (DM). Even if GCs are formed in individual DM halos, they must have lost the majority of the DM through dynamical processes such as mass segregation or tidal stripping. Using Fokker-Planck (FP) calculations, we investigate the dynamical evolution of three Galactic GCs with an assumption that they were formed in mini DM halos. We trace the amount of DM of 47 Tuc, NGC 1851, and M 15, which are a ‘disk/bulge’ cluster, an ‘old halo’ cluster, and a ‘young halo’ cluster, respectively. We find that these three GCs must have initially had insignificant amounts of DM, less than 10 percent of the initial stellar mass of each cluster.
Initial Dynamical Evolution of Star Clusters with Tidal Field
Authors: Park So-Myoung , Goodwin Simon P. , Kim Sungsoo S.
Published: March 2017

Observations have been suggested that star clusters could form from the rapid collapse and violent relaxation of substructured distributions. We investigate the collapse of fractal stellar distributions in no, weak, and very strong tidal fields. We find that the rapid collapse of substructure into spherical clusters happens quickly with no or a weak tidal field, but very strong tidal fields prevent a cluster forming. However, we also find that dense Plummer spheres are also rapidly destroyed in strong tidal fields. We suggest that this is why the low-mass star clusters cannot survive near the galactic centre which has strong tidal field.
Is the massive star cluster Westerlund 2 double? - A high resolution multi-band survey with the Hubble Space Telescope
Authors: Zeidler Peter , Nota Antonella , Sabbi Elena , Grebel Eva K. , Tosi Monica , Bonanos Alceste Z. , Pasquali Anna , Christian Carol , de Mink Selma E.
Published: March 2017

Westerlund 2 (Wd2) is one of the most massive young star clusters known in the Milky Way. The close proximity (4.16 kpc) to the Sun, and the young age (2.0 Myr) allow us to study star formation in detail at a high spatial resolution. We present results from our recent deep multi-band survey in the optical and near-infrared obtained with the Hubble Space Telescope. We demonstrated that, as expected, the region is affected by significant differential reddening with a median value of E(B − V)g = 1.87 mag. The distance was inferred from the dereddened color-magnitude diagrams using Padova isochrones. Analyzing the spatial distribution of stars we found that Wd2 consists of two sub-clumps, namely the main cluster of Westerlund 2 and a less well populated clump located to the North. We estimated the same age of 0.1–2.0 Myr for both sub-clumps, thus we conclude that they are likely coeval.
The Spectral Energy Distribution of the Earliest Phases of Massive Star Formation
Authors: Klein Randolf , Cooper Jennifer , Looney Leslie , Henning Thomas , Chakrabarti Sukanya , Shenoy Sachin
Published: March 2017

We have selected cold and massive (M > 100M⊙) cores as candidates for early phases of star formation from millimeter continuum surveys without associations at short wavelengths. We compared the millimeter continuum peak positions with IR and radio catalogs and excluded cores that had sources associated with the cores’ peaks. We compiled a list of 173 cores in over 117 regions that are candidates for very early phases of Massive Star Formation (MSF). Now with the Spitzer and Herschel archives, these cores can be characterized further. We are compiling this data set to construct the complete spectral energy distribution (SED) in the mid- and far-infrared with good spatial resolution and broad spectral coverage. This allow us to disentangle the complex regions and model the SED of the deeply embedded protostars/clusters. We present a status report of our efforts: a preview of the IR properties of all cores and their embedded source inferred from a grey body fit to the compiled SEDs.
Galactic flows and the formation of stellar clusters
Authors: Smilgys Romas , Bonnell Ian A.
Published: March 2017

We investigate the formation of stellar clusters from a Galactic scale SPH simulation. The simulation traces star formation over a 5.6 Myr timescale, with local gravitational instabilities resulting in ~ 105 solar masses of star formation in the form of sink particles. We investigate the time evolution of the physical properties of the forming clusters including their half-mass radii, their energies and the depletion time of the gas. Star formation is driven by the large scale flows which compress the gas to higher densities where self gravity takes over and collapse occurs. We show that the more massive clusters (up to ~ 2 × 104 solar masses) gather their material from of order 10 pc due to these large scale motions associated with the spiral arm passage and shock. The bulk of the gas becomes gravitationally bound near 1-2 Myr before sink formation, and in the absence of feedback, significant accretion ongoing on longer timescales. We trace the hierarchical merging process of cluster formation which naturally results in age spreads of order the crossing time of the original region which provides the gas reservoir for the cluster.
Early dynamical evolution of young substructured clusters
Authors: Dorval Julien , Boily Christian
Published: March 2017

Stellar clusters form with a high level of substructure, inherited from the molecular cloud and the star formation process. Evidence from observations and simulations also indicate the stars in such young clusters form a subvirial system. The subsequent dynamical evolution can cause important mass loss, ejecting a large part of the birth population in the field. It can also imprint the stellar population and still be inferred from observations of evolved clusters. Nbody simulations allow a better understanding of these early twists and turns, given realistic initial conditions. Nowadays, substructured, clumpy young clusters are usually obtained through pseudo-fractal growth and velocity inheritance. We introduce a new way to create clumpy initial conditions through a ”Hubble expansion” which naturally produces self consistent clumps, velocity-wise. In depth analysis of the resulting clumps shows consistency with hydrodynamical simulations of young star clusters. We use these initial conditions to investigate the dynamical evolution of young subvirial clusters. We find the collapse to be soft, with hierarchical merging leading to a high level of mass segregation. The subsequent evolution is less pronounced than the equilibrium achieved from a cold collapse formation scenario.
The influence of feedback from massive stars on the formation and emergence of massive clusters
Authors: Dale James E.
Published: March 2017

Massive star clusters are of fundamental importance both observationally, since they are visible at such great distances, and theoretically, because of their influence on the large–scale ISM. Understanding stellar feedback is a prerequisite for making sense of their formation and early evolution, since feedback influences cluster structure, star formation efficiency, and sets the timescales on which clusters emerge from their parent clouds to become optically visible. I review the progress made in understanding these issues from a numerical perspective.
Identifying and Characterizing Stellar Clusters Toward the Galactic Anti-Center from Pan-STARRS1 Survey
Authors: Lin C.-C. , Chen W.-P. , Hou J. , Chen L. , Shao Z.
Published: March 2017

The current sample of star clusters (SCs) is still incomplete beyond 1.8 kpc. The Pan-STARRS1 with its wide field of views and sensitive cameras provides us an opportunity to identify and characterize SCs as much as possible. By using a star counting algorithm, we obtained a total of 491 stellar density enhancements in a field of 20° × 20° toward the Galactic Anti-Center (GAC), of which 50 are known SCs. The remaining 441 candidates are verified with radii, interstellar reddening, distances, and ages with proper motions and multiple bands photometries. Our results push the completeness of SCs almost near the edge of GAC. With the revised SC sample, the separation between Sagittarius and Perseus arms are about 3.2 ± 0.2 kpc and the widths of the nearby spiral arms—Sagittarius, Orion, and Perseus—with are 1.4 ± 0.1, 1.6 ± 0.1, and 3.3 ± 0.2 kpc, respectively.
Is there a cluster in the massive star forming region IRAS 20126+4104?
Authors: Montes V. A. , Hofner Peter , Anderson C. , Rosero V.
Published: March 2017

A Chandra X-ray Observatory ACIS-I observation and a 6 cm continuum radio observation with the Karl G. Jansky Very Large Array (VLA) together with a multiwavelength study in infrared (2MASS and Spitzer) and optical (USNO-B1.0) shows an increasing surface density of X-ray sources toward the massive protostar. There are at least 43 YSOs within 1.2 pc distance from the massive protostar. This number is consistent with typical B-type stars clusters (Lada & Lada 2003).
Massive stellar systems: observational challenges and perspectives in the E-ELT era
Authors: Bono G. , Braga V. F. , Ferraro I. , Fiorentino G. , Gilmozzi R. , Iannicola G. , Magurno D. , Matsunaga N. , Monelli M. , Rastello S.
Published: March 2017

We introduce the empirical framework concerning optical and near-infrared (NIR) photometry of crowded stellar fields. In particular, we address the impact that linear detectors and analytical PSF played in improving the accuracy and the precision of multi-band color-magnitude diagrams (CMDs). We focus our attention on recent findings based on deep NIR images collected with Adaptive Optics (AO) systems at the 8-10m class telescopes and discuss pros and cons of the different approaches. We also discuss the estimate of the absolute age of globular clusters using a well defined knee along the lower main sequence. We mention the role which the current AO-assisted instruments will have in addressing longstanding astrophysical problems of the Galactic center. Finally, we outline the role of first generation of E-ELT instruments upon photometry and spectroscopy of crowded stellar fields.
Nuclear Star Clusters
Authors: Neumayer Nadine
Published: March 2017

The centers of galaxies host two distinct, compact components: massive black holes and nuclear star clusters. Nuclear star clusters are the densest stellar systems in the universe, with masses of ~ 107M⊙and sizes of ~ 5pc. They are almost ubiquitous at the centres of nearby galaxies with masses similar to, or lower than the Milky Way. Their occurrence both in spirals and dwarf elliptical galaxies appears to be a strong function of total galaxy light or mass. Nucleation fractions are up to 100% for total galaxy magnitudes of MB= −19mag or total galaxy luminosities of about LB= 1010L⊙and falling nucleation fractions for both smaller and higher galaxy masses. Although nuclear star clusters are so common, their formation mechanisms are still under debate. The two main formation scenarios proposed are the infall and subsequent merging of star clusters and the in-situ formation of stars at the center of a galaxy. Here, I review the state-of-the-art of nuclear star cluster observations concerning their structure, stellar populations and kinematics. These observations are used to constrain the proposed formation scenarios for nuclear star clusters. Constraints from observations show, that likely both cluster infall and in-situ star formation are at work. The relative importance of these two mechanisms is still subject of investigation.
Young and old massive star clusters and their stellar populations - Theoretical challenges for the next decade
Authors: Charbonnel Corinne
Published: March 2017

Several models presented in the literature compete to explain the origin of multiple stellar populations in globular clusters (GC), but they all fail to reproduce the large variety of present-day characteristics of these systems. In parallel, independent clues on GC early evolution may be derived from observations of young massive clusters (YMC) in the Local Group. But are these two populations of clusters related? And can we reconcile the informations and data concerning GCs and YMCs? Here we summarize some open questions on the nucleosynthetic origin of multiple stellar populations in GCs, on the actual evolution and characteristics of GC low-mass stars, and on early gas expulsion from massive clusters. We propose theoretical paths to be explored in the near future.
The super star cluster driven feedback in ESO338-IG04 and Haro 11
Authors: Bik A. , Östlin G. , Menacho V. , Adamo A. , Hayes M. , Melinder J. , Amram P.
Published: March 2017

The stellar content of young massive star clusters emit large amounts of Lyman continuum photons and inject momentum into the inter stellar medium (ISM) by the strong stellar winds of the most massive stars in the cluster. When the most massive stars explode as supernovae, large amounts of mechanical energy are injected in the ISM. A detailed study of the ISM around these massive cluster provides insights on the effect of cluster feedback.

We present high quality integral field spectroscopy taken with VLT/MUSE of two starburst galaxies: ESO 338-IG04 and Haro 11. Both galaxies contain a significant number of super star clusters. The MUSE data provide us with an unprecedented view of the state and kinematics of the ionized gas in the galaxy allowing us to study the effect of stellar feedback on small and large spatial scales. We present our recent results on studying the ISM state of these two galaxies. The data of both galaxies show that the mechanical and ionization feedback of the super star clusters in the galaxy modify the state and kinematics of the ISM substancially by creating highly ionized bubbles around the cluster, making the central part of the galaxy highly ionized. This shows that the HII regions around the individual clusters are density bounded, allowing the ionizing photons to escape and ionize the ISM further out.
Strömgren-Hβ photometry of the young open cluster NGC 6913
Authors: Kaltcheva Nadia , Golev Valeri , Beaver John , Lund Steven , Briley Michael
Published: March 2017

We present new CCD uvbyβ photometry of about 50 stars located in the central region of the open cluster NGC 6913. The individual stellar distances and color excesses of established cluster’s members are analyzed and new estimate of the cluster’s distance is provided.
Searching for Possible Members of Star Moving Groups in the Kepler Field
Authors: Chen Chang Yao , Chen W. P. , Luo Ali
Published: March 2017

We present identification of candidate members of the Beta Pictoris, AB Doradus, and TW Hydrae moving star groups. Our pilot study toward the Kepler field, where a multitude of stellar parameters are available, led to a list of 19 highly probable candidates that share the same range of distance and space (tangential and radial) motion as known members in a moving group. A few candidates lack radial velocity data, but are ROSAT X-ray sources, so are considered as likely young stars.
Comparing ALMA, VLT, and HST data for Massive, Young Clusters in Grand-Design Spirals
Authors: Grosbøl Preben , Dottori Horacio
Published: March 2017

A population of young, massive stellar cluster complexes with near-infrared (NIR) colors indicating high extinction (i.e. Av ~ 7m) was identified on HAWK-I/VLT images of several nearby, grand-design spiral galaxies. Models suggest that they are very young cluster complexes still embedded in a dust/gas envelope which will be expelled after 5-7 Myr. This type of very young, embedded clusters are not seen in optical studies using HST data.

A detailed comparison of HST and HAWK-I images was done to better understand the discrepancy between the optical and NIR detection of stellar clusters in nearby galaxies. More than 70% of the NIR clusters are located close to dust lanes which would make an optical detection difficult. A comparison of the ALMA CO(1-0)-map of NGC 4321 and the young, massive clusters shows that 60% of them have CO emission within 2“ indicating a correlation between giant molecular clouds and formation of massive clusters.
NGC 346: Looking in the Cradle of a Massive Star Cluster
Authors: Gouliermis Dimitrios A. , Hony Sacha
Published: March 2017

How does a star cluster of more than few 10,000 solar masses form? We present the case of the cluster NGC 346 in the Small Magellanic Cloud, still embedded in its natal star-forming region N66, and we propose a scenario for its formation, based on observations of the rich stellar populations in the region. Young massive clusters host a high fraction of early-type stars, indicating an extremely high star formation efficiency. The Milky Way galaxy hosts several young massive clusters that fill the gap between young low-mass open clusters and old massive globular clusters. Only a handful, though, are young enough to study their formation. Moreover, the investigation of their gaseous natal environments suffers from contamination by the Galactic disk. Young massive clusters are very abundant in distant starburst and interacting galaxies, but the distance of their hosting galaxies do not also allow a detailed analysis of their formation. The Magellanic Clouds, on the other hand, host young massive clusters in a wide range of ages with the youngest being still embedded in their giant HII regions. Hubble Space Telescope imaging of such star-forming complexes provide a stellar sampling with a high dynamic range in stellar masses, allowing the detailed study of star formation at scales typical for molecular clouds. Our cluster analysis on the distribution of newly-born stars in N66 shows that star formation in the region proceeds in a clumpy hierarchical fashion, leading to the formation of both a dominant young massive cluster, hosting about half of the observed pre–main-sequence population, and a self-similar dispersed distribution of the remaining stars. We investigate the correlation between stellar surface density (and star formation rate derived from star-counts) and molecular gas surface density (derived from dust column density) in order to unravel the physical conditions that gave birth to NGC 346. A power law fit to the data yields a steep correlation between these two parameters with a considerable scatter. The fraction of stellar over the total (gas plus young stars) mass is found to be systematically higher within the central 15 pc (where the young massive cluster is located) than outside, which suggests variations in the star formation efficiency within the same star-forming complex. This trend possibly reflects a change of star formation efficiency in N66 between clustered and non-clustered star formation. Our findings suggest that the formation of NGC 346 is the combined result of star formation regulated by turbulence and of early dynamical evolution induced by the gravitational potential of the dense interstellar medium.
The Composition of the Bulge Globular Cluster NGC 6273
Authors: Pilachowski C. A. , Johnson C. I. , Rich R. M. , Caldwell N. , Mateo M. , Bailey J. I. , Crane J. D.
Published: March 2017

Observations of red giants in the Bulge globular cluster NGC 6273 with the Michigan/Magellan Fiber System (M2FS) mounted on the Nasmuth-East port of the Magellan-Clay 6.5-m telescope at the Las Campanas Observatory reveal a spread in metallicity. Members have been confirmed with radial velocity. NGC 6273 has at least two populations separated by 0.2-0.3 dex in [Fe/H]. The sodium and aluminum abundances are correlated while the magnesium and aluminum abundances are anti-correlated. The cluster also shows a rise in the abundance of the s-process element lanthanum with [Fe/H] similar to other massive clusters. The cluster contains a possible third population depleted in most elements by 0.3 dex.
Gene mobility promotes the spread of resistance in bacterial populations
Authors: Stevenson Cagla , Hall James P J , Harrison Ellie , Wood A Jamie , Brockhurst Michael A
Published: March 2017

Theory predicts that horizontal gene transfer (HGT) expands the selective conditions under which genes spread in bacterial populations. Whereas vertically inherited genes can only spread by positively selected clonal expansion, mobile genetic elements can drive fixation of genes by infectious HGT. We tested this using populations of Pseudomonas fluorescens and the conjugative mercury resistance (HgR) plasmid pQBR57. HGT expanded the selective conditions allowing the spread of HgR: Chromosomal HgR only increased in frequency under positive selection, whereas plasmid-encoded HgR reached fixation with or without positive selection. Tracking plasmid dynamics over time revealed that the mode of HgR inheritance varied across mercury environments. Under mercury selection, the spread of HgR was driven primarily by clonal expansion while in the absence of mercury HgR dynamics were dominated by infectious transfer. Thus, HGT is most likely to drive the spread of resistance genes in environments where resistance is useless.
A tipping point in refreezing accelerates mass loss of Greenland’s glaciers and ice caps
Authors: Noël B. , van de Berg W. J , Lhermitte S. , Wouters B. , Machguth H. , Howat I. , Citterio M. , Moholdt G. , Lenaerts J. T. M. , van den Broeke M. R.
Published: March 2017

Melting of the Greenland ice sheet (GrIS) and its peripheral glaciers and ice caps (GICs) contributes about 43% to contemporary sea level rise. While patterns of GrIS mass loss are well studied, the spatial and temporal evolution of GICs mass loss and the acting processes have remained unclear. Here we use a novel, 1 km surface mass balance product, evaluated against in situ and remote sensing data, to identify 1997 (±5 years) as a tipping point for GICs mass balance. That year marks the onset of a rapid deterioration in the capacity of the GICs firn to refreeze meltwater. Consequently, GICs runoff increases 65% faster than meltwater production, tripling the post-1997 mass loss to 36±16 Gt−1, or ∼14% of the Greenland total. In sharp contrast, the extensive inland firn of the GrIS retains most of its refreezing capacity for now, buffering 22% of the increased meltwater production. This underlines the very different response of the GICs and GrIS to atmospheric warming.
Steviol glycosides enhance pancreatic beta-cell function and taste sensation by potentiation of TRPM5 channel activity
Authors: Philippaert Koenraad , Pironet Andy , Mesuere Margot , Sones William , Vermeiren Laura , Kerselaers Sara , Pinto Sílvia , Segal Andrei , Antoine Nancy , Gysemans Conny , Laureys Jos , Lemaire Katleen , Gilon Patrick , Cuypers Eva , Tytgat Jan , Mathieu Chantal , Schuit Frans , Rorsman Patrik , Talavera Karel , Voets Thomas , Vennekens Rudi
Published: March 2017

Steviol glycosides (SGs), such as stevioside and rebaudioside A, are natural, non-caloric sweet-tasting organic molecules, present in extracts of the scrub plant Stevia rebaudiana, which are widely used as sweeteners in consumer foods and beverages. TRPM5 is a Ca2+-activated cation channel expressed in type II taste receptor cells and pancreatic β-cells. Here we show that stevioside, rebaudioside A and their aglycon steviol potentiate the activity of TRPM5. We find that SGs potentiate perception of bitter, sweet and umami taste, and enhance glucose-induced insulin secretion in a Trpm5-dependent manner. Daily consumption of stevioside prevents development of high-fat-diet-induced diabetic hyperglycaemia in wild-type mice, but not in Trpm5−/− mice. These results elucidate a molecular mechanism of action of SGs and identify TRPM5 as a potential target to prevent and treat type 2 diabetes.
Erratum: PARP1 promotes gene expression at the post-transcriptional level by modulating the RNA-binding protein HuR
Authors: Ke Yueshuang , Han Yanlong , Guo Xiaolan , Wen Jitao , Wang Ke , Jiang Xue , Tian Xue , Ba Xueqing , Boldogh Istvan , Zeng Xianlu
Published: March 2017

Nature Communications 8 Article number:14632 (2017); Published: 8 March 2017; Updated: 31 March 2017 The original version of this Article contained an error in the spelling of post-transcriptional in the title of the paper. This has now been corrected in both the PDF and HTML versions of the Article.
Evolution of full-length genomes of HBV quasispecies in sera of patients with a coexistence of HBsAg and anti-HBs antibodies
Authors: Zhou Tai-Cheng , Li Xiao , Li Long , Li Xiao-Fei , Zhang Liang , Wei Jia
Published: March 2017

Although the evolutionary changes of viral quasispecies are correlated to the pathological status of a disease, little is known in the coexistence of hepatitis B surface antigen (HBsAg) and antibodies to these antigens (anti-HBs). To examine evolutionary changes in hepatitis B virus (HBV) and their relationship to the coexistence of HBsAg and anti-HBs antibodies, HBV genomes in patients with a coexistence of HBsAg and anti-HBs antibodies (experimental group) and HBsAg positive without anti-HBs (control group) were assessed. Our results showed that quasispecies diversity was significantly higher in the experimental group for large HBsAg (LHBsAg), middle HBsAg (MHBsAg), and HBsAg genes. LHBsAg harbored dN/dS values eight times higher in the experimental group; however, the mean dN/dS ratios in genes HbxAg, Pol and PreC/C of the experimental patients had an opposite trend. Phylogenetic trees in the experimental group were more complex than the control group. More positive selection sites, mutations and deletions were observed in the experimental group in specific regions. Furthermore, several amino acid variants in epitopes were potentially associated with the immune evasion. In conclusion, cumulative evolutionary changes in HBV genome that facilitate immune evasion provide insights into the genetic mechanism of a coexistence of HBsAg and anti-HBs antibodies.