bluuebunny/crossref_metadata_2025 huggingface dataset:
Bridging the gaps in test interpretation of SARS-CoV-2 through Bayesian network modelling
Authors: Wu Yue , Foley David , Ramsay Jessica , Woodberry Owen , Mascaro Steven , Nicholson Ann E. , Snelling Tom
Published: June 2021

In the absence of an established gold standard, an understanding of the testing cycle from individual exposure to test outcome report is required to guide the correct interpretation of severe acute respiratory syndrome-coronavirus-2 reverse transcriptase real-time polymerase chain reaction (RT-PCR) results and optimise the testing processes. Bayesian network models have been used within healthcare to bring clarity to complex problems. We use this modelling approach to construct a comprehensive framework for understanding the real-world predictive value of individual RT-PCR results.

We elicited knowledge from domain experts to describe the test process through a facilitated group workshop. A preliminary model was derived based on the elicited knowledge, then subsequently refined, parameterised and validated with a second workshop and one-on-one discussions.

Causal relationships elicited describe the interactions of pre-testing, specimen collection and laboratory procedures and RT-PCR platform factors, and their impact on the presence and quantity of virus and thus the test result and its interpretation. By setting the input variables as ‘evidence’ for a given subject and preliminary parameterisation, four scenarios were simulated to demonstrate potential uses of the model.

The core value of this model is a deep understanding of the total testing cycle, bridging the gap between a person's true infection status and their test outcome. This model can be adapted to different settings, testing modalities and pathogens, adding much needed nuance to the interpretations of results.
Direction-dependent turning leads to anisotropic diffusion and persistence
Authors: LOY N. , HILLEN T. , PAINTER K. J.
Published: June 2021

Cells and organisms follow aligned structures in their environment, a process that can generate persistent migration paths. Kinetic transport equations are a popular modelling tool for describing biological movements at the mesoscopic level, yet their formulations usually assume a constant turning rate. Here we relax this simplification, extending to include a turning rate that varies according to the anisotropy of a heterogeneous environment. We extend known methods of parabolic and hyperbolic scaling and apply the results to cell movement on micropatterned domains. We show that inclusion of orientation dependence in the turning rate can lead to persistence of motion in an otherwise fully symmetric environment and generate enhanced diffusion in structured domains.
Predictors and moderators of outcomes in mindfulness-based cognitive therapy intervention for early breast cancer patients
Authors: Tamura Noriko , Park Sunre , Sato Yasunori , Sato Yasuko , Takita Yuka , Ninomiya Akira , Sado Mitsuhiro , Mimura Masaru , Fujisawa Daisuke
Published: June 2021

Objectives

To deliver mindfulness-based cognitive therapy (MBCT) efficiently, the present study aimed (1) to identify predictors and moderators of patients who benefit from MBCT for psychological distress and (2) to explore the initial treatment reaction to identify the optimal number of sessions that produce a significant clinical effect.

Methods

This is the secondary analysis of a randomized controlled trial of MBCT for breast cancer patients (N= 74). We classified the participants into remitters vs. non-remitters, and responder vs. non-responders, according to the total score of the Hospital Anxiety and Depression Scale at the end of the intervention. We conducted multivariate analyses to explore for predictors of response and remission. We adopted generalized estimating equations to explore the optimal number of sessions.

Results

Sociodemographic and clinical backgrounds did not have significant influence on the treatment outcomes of the MBCT. Better program adherence, which was represented as the participants’ better attendance to the MBCT program, was a significant predictor of both remission and response [odds ratio (OR) = 1.90, 95% confidence interval (CI) 1.25–2.89,p= 0.003, and OR = 1.72, 95% CI 1.12–2.65,p= 0.013, respectively]. It was not until seventh session that the remission rate exceeded 50% and the response rate showed significance.

Significance of results

Sociodemographic and clinical characteristics did not significantly influence the treatment outcomes, while homework minutes and class attendance had significant effects on treatment outcomes. This implies that MBCT is recommended to any cancer patient, if he/she is motivated to the program, regardless of their sociodemographic and clinical characteristics. Patients are encouraged to attend a standard MBCT program (eight sessions) and do the assigned homework as intensely as possible. Further studies with larger sample and objective measurements are desired.
Joint Discussion 1: Abundance Ratios in the Oldest Stars
Authors: Barbuy Beatriz , Bessell Michael S.
Published: June 2021

Joint Discussion 1 was supported by Division IV (Stars) and Commission 29 (Stellar Spectra), and co-supported by Commissions 28 (Galaxies), 36 (Theory of Stellar Atmospheres) and 37 (Stellar Clusters and Associations). Members of the scientific organizing committee were: N. Arimoto (Japan), B. Barbuy (Brazil), T. Beers (USA), J. Bergeron (Germany), M. Bessell (Australia), R. Cayrel (France), G. Gilmore (UK), B. Gustafsson (Sweden), F. Matteucci (Italy), P. Nissen (Den-mark), and M. Rich (USA).

The inspiration for this meeting was the growing overlap and connections between previously separate areas of astrophysical research, namely, studies of stellar abundances, the bulges of galaxies, the gaseous components of nearby galaxies and the clouds (some of which may be primordial) responsible for the narrow absorption lines in quasars.

The signature of the early chemical evolution of our Galaxy is imprinted in the abundance ratios of the oldest stars. We recall that element ratios are determined by a mix of the relative rates of different types of supernovae, the stellar IMF, and the relative histories of star formation rates and gaseous flows, and thus encapsulate much of the history of star formation and ISM evolution in galaxies. Hence, abundance ratios in stars are a primary probe for testing theories of galaxy formation and evolution.

We do not know how the Galaxy formed: both the Eggen, Lynden-Bell & Sandage (1962) and the Searle & Zinn (1978) scenarios may be accommodated in the recent proposal of van den Bergh (1993) where the inner Galaxy follows ELS, whereas the outer Galaxy formation conforms to the Searle-Zinn proposition. A combination of abundance ratios, ages derived from colour-magnitude diagrams, and kinematical properties, can give us the required information to trace the past history of our Galaxy. We note here, that although stellar evolution and model atmospheres are not discussed in the proceedings both topics are of fundamental underlying importance. Model atmospheres are used to derive temperatures, colors and bolometric corrections of stars that are used not only in abundance analyses but also in deriving the ages of stars by comparing CM diagrams with HR diagrams. This process is under close scrutiny because of the apparent difference between the ages of the oldest stars and the expansion age of the universe.
Abundance Ratios in Composite Stellar Populations with Special Emphasis on Elliptical Galaxies
Authors: von Alvensleben Uta Fritze -
Published: June 2021

Abundance Ratios are observed in a wide variety of instances addressed in this volume: in Gas and Stars, Simple Stellar Populations (SSPs) like star clusters, and, finally, in Composite Stellar Populations (CSPs) like E/SO galaxies (Bulges, spheroidal galaxies, Merger Remnants, etc.) on which the focus of this contribution will be. I’ll briefly review the observational situation and the current interpretation and then cast some doubt on the latter from our own chemically consistent spectrophotometric modelling results.
Relation Between BCDS and Blue LSBGS
Authors: Bergvall Nils , Östlin Göran , Pharasyn Arnaud , Rönnback Jari , Masegosa Josefa
Published: June 2021

Two important questions are connected to the evolutionary history of blue compact dwarf galaxies (BCDs): the triggering mechanism of the starburst and the properties of the precursor(s) and successor. The halos of many BCDs show red colours indicating that the host galaxy is in fact of early type. But where did the gas come from? Was it there from the start in a quiescent mode or was it fed by a merger with an intergalactic gas cloud or a gas-rich dwarf? Is there a general answer to this question or are there different families of BCDs?

The BCDs generating most of the interest are those with low chemical abundances, typically 10% solar. The only plausible precursors in this case are metal-poor dis, LSBGs or pure HI clouds (e.g. Thuan & Seitzer 197, ApJ 231, 680). In a comparison between LSBGs and BCDs Taylor et al. (e.g. 1997, ApJ 480, 524; 1996, ApJS 107, 143) found an excess of HI rich companions in the environments of BCDs which they interpret as a support of tidal triggering. We have studied a few massive (~ 109Mʘ ) metal- poor blue compact galaxies (BCGs). These are too bright to be classified as dwarfs but define an extension of the BCD family. For simplicity we will in the following use the common abbrevation BCD. In a search for possible precursors we have studied a sample of blue LSBGs with metallicities similar to BCDs (5-15%).
Star Formation Histories of Local Group Dwarf Galaxies
Authors: Grebel E.K.
Published: June 2021

The Local Group contains 37 currently known or probable member galaxies within a radius of 1.8 Mpc (Grebel 1997a). 31 of these galaxies are dwarf galaxies with MB > -17 mag. The most frequent galaxy types are low-mass, gas-poor dwarf spheroidal (dSph) galaxies, which are dominated by old and intermediate-age populations, and more massive, gas-rich dwarf irregular (dIrr) galaxies with recent star formation. DSph galaxies have been found mostly in close vicinity to the large spiral galaxies in the Local Group, while dirr galaxies tend to be more distant and isolated.
Compact Galaxies at Z = 0.2-1.3: Implications for Galaxy Evolution and the Star Formation History of the Universe
Authors: Guzman R. , Phillips A.C. , Gallego J. , Koo D.C.
Published: June 2021

We study the global properties of 51 compact field galaxies with redshifts z ~ 0.2 - 1.3 and apparent magnitudes I814 < 23.74 in the flanking fields of the Hubble Deep Field. All these galaxies have angular half-light radii re < 0.5 arcsec. Keck spectra covering ~4000-9000 Å, combined with HST І814 images and Keck V-band images, were used to derive redshifts, V606 - I814 colors, absolute blue magnitudes (MB), linear half-light radii (Re), blue average surface brightnesses within Re (SBe), velocity widths (σ), virial masses (M), mass-to-light ratios (M/L), excitations (O[III]/Hβ), and star formation rates (SFR). The results of this study can be summarized as follows:

(i):

Only 12% of the 51 compact galaxies have absorption-line dominated spectra, while 88% show strong, narrow emission lines, similar to the so-called CNELGs (e.g., Koo, this volume).

(ii):

Despite being very luminous (i.e., LB ~ L*; see figure la), compact emission-line galaxies are low-mass stellar sytems (i.e., M ≤ 1010 Mʘ, typically; see figure lb).

(iii):

Roughly 60% of the compact emission-line galaxies have colors, sizes, surface brightnesses, luminosities, velocity widths, excitations, star formation rates, and mass-to-light ratios characteristic of young, star-forming HII galaxies (see figures 1 and 2). The remaining 40% form a more heterogeneous class of evolved starbursts, similar to local disk starburst galaxies.

(iv):

Without additional star formation, galaxy evolution models predict that HII-like distant compacts will fade to resemble today’s spheroidal galaxies such as NGC 205 (Koo, this volume).
The Planetary Theories and The Precession of the Ecliptic
Authors: Bretagnon P.
Published: June 2021

In this paper, I give the present state of the analytical planetary theories by describing the general theories and the secular variation theories, the variations of the ecliptic with respect to the ecliptic J2000, the utilization of the analytical planetary theories in the calculation of the precession-nutation of the equator and in the calculation of the expressions of transformation between the barycentric and geocentric reference systems. At last, I describe the construction of new planetary theories undertaken at the Bureau des longitudes.

The analytical planetary theories arise in two forms: the general theories give, with a low accuracy, the variations of the elements of the planets over several million years; the secular variation theories reach a high accuracy over time spans of a few thousands of years.

In all these solutions, the motion of the planets is represented with 6 elements: a, the semi major axis, λ, the mean longitude and the variables k = e cos ϖ, h = e sin ϖ, q = sin ½ cos Ω, p = sin ½ sin Ω where e represents the eccentricity of the orbit, w the longitude of the perihelion, i the inclination of the orbit about the ecliptic J2000 and Ω the longitude of the node.
The Theory of the Nutation for a Rigid Earth Model: Current State of the Situation
Authors: Souchay J. , Kinoshita H.
Published: June 2021

Whereas no particular attention was paid to the theory of the nutation for a rigid Earth model, for more than a decade after the adoption by the International Astronomical Union (IAU) of coefficients as calculated and listed by Kinoshita (1977), an increasing number of studies have been done in the recent years aiming to improve this theory. The improvement became necessary mainly because of the big parallel improvement of the VLBI observations itself, which leads to present determinations of some coefficients of nutation at the level of a few 10μas. Therefore the amelioration of the theory of the nutation for a rigid Earth model can be divided in two aspects: one is to consider a smaller level of truncation of the coefficients of nutation; the other is to evaluate in the best way the coefficients already taken into account, particularly the leading coefficients which are typically those subject to the largest absolute differences.
Extension of the Optical Reference Frame:Space Based
Authors: Röser S.
Published: June 2021

At its 23rd General Assembly, Kyoto 1997, the IAU decided that the International Celestial Reference Frame (ICRF) should be defined by the positions of 608 compact extragalactic radio sources (Ma & Feissel 1997), with the Hipparcos Catalogue (ESA 1997) being its practical realization at optical wavelengths. Although the Hipparcos instrument was unable to observe the defining sources of the ICRF directly in the optical regime, it is linked to the ICRF via a number of auxiliary observations (Kovalevskyet al.1997). The Hipparcos Catalogue is the first celestial reference frame which is constructed from observations not made from the surface of the Earth.
Maintenance of the ICRF: Radio
Authors: Fey Alan L.
Published: June 2021

Extragalactic radio sources are assumed to be very distant and thus should exhibit little or no detectable proper motions. A reference frame defined by the positions of extragalactic radio sources may be said to be a quasi-inertial frame (i.e. a frame whose basis is inertial) with little or no time dependency. Unfortunately, although extragalactic sources are good as ICRF objects, most extragalactic sources display intrinsic structure on angular scales larger than the accuracy of their position estimates. Temporal variations of the intrinsic structure of these objects will result in apparent motion when observations are made at several epochs. Because the underlying physics of extragalactic sources is not as well understood as that of the stars which define the stellar reference frame, we can only describe with certainty what the radio sources did during the particular interval of time covered by previous observations. We cannot predict theoretically what behavior can be expected in the future. It is therefore necessary to regularly measure the structure of ICRF sources, and monitor their changes, in order to maintain the ICRF and make it more useful to astronomers.
Evidence of Angular Momentum Loss in the Eclipsing Binary VW Cephei
Authors: Devita M.J. , Bradstreet D.H. , Guinan E.F. , Glownia Z.
Published: June 2021

VW Cep is one of the brightest and longest observed short-period (P = 6.67 hours) W UMa type binaries. It consists of a G5V and K0V components in contact with their Roche surfaces. We investigated complex period changes based upon eclipse timings from the past 70 years. In addition to the well-known 30 year light time effect due to the presence of a third star in the system, we find evidence for a long term decrease in the orbital period of dP/dt = −0.02 sec/yr. This decrease in period could arise from angular momentum loss from the binary or mass exchange between components. From these timings we have refined the properties of the tertiary component and redetermined its mass and orbital parameters. After correcting the O-C’s for the third body and the steady decrease in Keplerian period, we uncovered small systematic deviations in the residual O-C’s. We are studying these second order period variations, possibly arising from mass loss in winds and/or mass flow between components, to determine if they correlate with known cycles of spot and surface activity.
Evolutionary Changes in the Eclipsing Binary β Lyrae
Authors: Harmanec P.
Published: June 2021

An attempt at the first direct test of the theory of large-scale mass transfer between the components of a binary system is discussed. It is argued that β Lyr is the only binary in the sky for which such a test is conceivable.
Search for Signs of a New Outburst in the Quiescent State of CH Cygni
Authors: Kotnik-Karuza D. , Jurdana-Šepić R.
Published: June 2021

A review of our investigations of CH Cygni in its inactive state during the period 1987-1989 has been given. Optical spectra reveal the development of physical conditions in the photosphere of the cool component as well as changes in the accretion complex around the hot component. The apparently quiescent star was actually evolving in trainsition between adjacent outbursts.
CCD Observations and Analysis of the W UMA Type Binary SS Arietis
Authors: Han Wonyong , Kim Chun-Hwey , Lee Jae Woo , Kim Ho-Il , Lee Woo-Baik
Published: June 2021

The BVR CCD observations of W UMa-type eclipsing binary SS Arietis were made for ten nights from November 1996 to December 1996 at the Sobaeksan Astronomy Observatory. From the observed light curves, nine new times of minimum lights were derived from the Kwee and van Woerden’s method. Improved light elements for this system were determined from these minimum lights with all the published minima. The analysis of the times of minima of SS Ari confirms that the orbital period of SS Ari has been suffering from a sinusoidal variation as the suggestions of other previous investigators (Kaluzny & Pojmanski 1984, Demircan & Selam 1993). The calculation shows that the cyclic period change has a period of about 56.3yrs with an amplitude of about 0.d052. The period variation has been discussed in terms of two potential mechanisms: 1) the light-time effect due to a hypothetical third body and 2) deformations in the convective envelope of a magnetically active component. The BVR light curves of SS Ari observed for about one month showed the existence of cycle to cycle light variations. Long-term light changes of SS Ari are discussed in terms of the period variation of the binary system.
Search for Signs of A New Outburst in the Quiescent State of CH CYG
Authors: Kotnik-Karuza D. , Jurdana Šepić R.
Published: June 2021

Our high-resolution optical spectroscopic survey of the symbiotic star CH Cyg, extending over the quiescent period 1987 - 1989 between two outbursts, shows that the spectrum did not completely lose its symbiotic character. Moreover, signs of radiation of the hot source were present, not only as remnants from the previous outburst, but also as an indication of a new one. Some of the evidences which support this idea are following:

• Variation of excitation and vibration temperatures of neutral metals and TiO moleculs respectively

• Untypical microturbulent velocity dependance of the excitation potential of the lower state for Fe I

• Double-peaked Balmer profiles of Ha and Hb with temporary disappearance of the central absorption

• Presence of forbbiden emission lines [FeII] [ SII] [NeIII] together with OIII with complex profile and variable intensity.
The Variations in Light Curves of Contact Binary AU SER
Authors: Yue-Rong Li Zong-Yun Ding
Published: June 2021

Photometry of AU Ser, a contact binary in poor thermal contact, was made using the 1-meter reflector of the Yunnan Observatory, China, in 1991, 1992and 1995. Our observations, together with Binnendijk’s (1972), show variations in light curves similar to ones of VW Cep:

1)

Changes in sign and value of O’Connell effect. According to Binnendijk(1972), the maximum following primary minimum was higher than the other maximum, i.e., the O’Connell effect was positive. In our 1991 and 1992 light curves it became negative. After three years, however, the situation has reversed again.

2)

Variations of the difference between minimum depths.The difference in 1991 was smaller than that in 1969 and 1970. It got smallest in 1992 and largest in 1995. The difference increases by about 0.3 mag in three years, which is hard to explained.

3)

The phase shift. The observed minimum phase in 1991, 1992 and 1995 have progressively displaced forward with respect to computed minimum phase according to Binnendijk’s ephemeris. The O-C diagram seems to indicate a sudden decrease of orbital period after 1970. Also, short period oscillations have been found at frequencies of 0.0003, 0.005 and 0.0075 Hz. Flickering. with an average amplitude of about 0.05 mag, can be seen in the light curves. The power spectral analysis suggest the existence of oscillations. It is unusual that such oscillations exist in a contact binary.
Solitons in the Close Binary Systems
Authors: Tanabe Kenji
Published: June 2021

Propagation of the surface waves of the lobe-filing components of close binary systems is investigated theoretically. Such waves are considered to be analogous to the gravity waves of water on the earth. As a result, the equations of the surface wave in the rotating frame of reference are reduced to the so-called Kortewegde Vries (KdV) equation and non-linear Schroedinger (NLS) equation according to its ”depth”. Each of these equations is known to have the solution of soliton. When this soliton is sent to the other component of the binary system through the Lagrangian point, it can give rise to the flare activity observed in some kinds of close binary systems.
Star Formation: Can There BE a Break in the IMF Near 0.1Mʘ?
Authors: Nakano Takenori
Published: June 2021

The initial mass function of stars (IMF) at small masses depends on several factors. First, it depends on the mass function of cloud cores in which stars form. Second, there must be a lower limit to the core mass for contraction; very small mass cores may not contract even if they exist. This must affect greatly the IMF near its lower end. Third, not all core matter may become stars; we must determine the stellar mass M*, or the star formation efficiency M*/Mcc, as a function of the mass of the cloud core, Mcc. In this paper we discuss the second and third points.
Multicolor Survey For High Redshift Quasars By Kiso Schmidt Telescope
Authors: Yamagata Tomohiko , Kawara Kimiaki , Aoki Tsutomu , Sofue Yoshiaki
Published: June 2021

Several groups have been successful in the survey of high-redshift (z > 4) quasars. For example, Schneider et al. (1994) and Schmidt et al. (1995) were successful in detecting 90 quasars with 2.75 < z < 4.75, R < 21 for 62deg2 using Palomar Transit Grism. Among them, there are 9 quasars with z > 4.0. Storrie-Lombardi et al. (1996) were detected 31 quasars with z > 4.0, mT < 19 for 2500deg2 by APM photographic multicolor survey using UK Schmidt telescope. Survey observations of quasars up to now have to select one of the following conditions; wide field surveys using photographic Schmidt plate which cover large areas but do not go faint enough, or deep surveys using large telescopes which go faint magnitude but which cover relatively small areas.
Electronic Publishing: Now and the Future
Authors: Hearn A.G.
Published: June 2021

Electronic publishing of journals has already arrived, and is established. The Astrophysical Journal and Letters, Astronomy and Astrophysics Supplements and New Astronomy have been publishing a parallel electronic edition since the beginning of 1997. Astronomy and Astrophysics will follow in 1998, and the Monthly Notices of the Royal Astronomical Society are being developed. The American Astronomical Society has been the leader in developing electronic publishing in astrophysics. They have led not only by being first, but also by the high standards of their electronic publication.

One of the stories that school children in Great Britain learn at an early age is about King Canute II. Canute was a Danish king who ruled part of what is now Great Britain from 1016 to 1035. He is famous because he sat bythe sea as the tide was coming in and commanded the tide to go back. It didnot.

Electronic publication is going to bring many changes to the way research is done and published. There are obvious advantages and disadvantages. There are certainly problems which we have not yet realized. The purpose of this Joint Discussion is to stimulate a discussion of what the international astrophysical community would like from electronic publishing. Please do not say that you want electronic publishing to go away, because then you will be behaving like King Canute. But the publishers of journals and the bodies responsible for maintaining the quality of publication are feeling their way into completely new territory. To exploit electronic publishing to the full, and to minimize the disadvantages, discussion in the community is needed.

Electronic publishing will bring great connectivity into journals. While looking at one paper, a click on the mouse will immediately connect with another paper published in another journal. Large tables, theoretical or observational, will be read in the same way from databases. An electronic publication will longer be static. It can be modified to refer to papers published later, it can contain movies or computer programs that can be executed online.
Electronic Publishing in Astronomy
Authors: Boyce Peter B.
Published: June 2021

Links are important. The providers of electronic astronomical data are linked together the way no other science is. Electronic journals are part of this distributed, linked resource. Permanence is important. The AAS journals use a new publishing process which ensures the ability to maintain permanent access to our electronic journals. Process is important. With the right process, we have been able to add links automatically to our journal; links to references, links to citations (where the electronic material exists) and internal links for ease of navigation within the journal. Readers like this. Links are important.
Electronic Publishing: The New Roles of CDS
Authors: Genova F. , Bartlett J.G. , Bonnarel F. , Dubois P. , Egret D. , Fernique P. , Jasniewicz G. , Lesteven S. , Monier R. , Ochsenbein F. , Wenger M.
Published: June 2021

The Centre de Données astronomiques de Strasbourg (CDS) has dealt with bibliographic information for many years. References of publications, published observational data related to objects, data tables, nomenclature, have been homogenized and organized into information retrieval systems: SIMBAD, the reference database for the identification and bibliography of astronomical objects; the catalogue service and the VizieR catalogue Browser, for data tables; the Dictionary of Nomenclature of Astronomical objects, which is now maintained by the CDS. Evolution in recent years has brought the Data Centers closer to the publishing process. General standards for astronomy, for the description of references and of data tables, have been proposed and implemented. Data tables from papers are now directly published in electronic form, and distributed on-line by the Data Centers. The emergence of fully electronic publication paves the way to innovative new services, linking the journals to other sources of informations (data bases, tables, then images, data archives), and making use of new methods for information retrieval. This also has an effect on the publishing process, with the possibility to implement new checks and links from text to other kinds of information (from objects names, positions, etc.). The CDS will bring some of thekey features in the evolution towards a fully linked astronomy information system, in close collaboration with the journal editors, the ADS, the other Data Centers, and the data providers.
The Stellar Variability From Hipparcos Photometry
Authors: Grenon M.
Published: June 2021

During the development of the Hipparcos satellite, the opportunity to use the star mapper to perform a whole sky two colour intermediate accuracy photometric survey, and the main-mission detector for high accuracy photometry of target stars was identified. The instrument was optimised and the pre-launch calibrations performed to pre-determine the pass-bands with an accuracy sufficient to cope, in-orbit, with the foreseen aging of the detection chains. Photometry became an important by-product of the mission, very complementary to the astrometric results. It was the first opportunity to monitor the sky during 3-4 years without selection biases and with a precision similar to that achieved from the ground with the best classical techniques. A systematic detection of small amplitude variables was the expected return.
Binaries in Acceleration and Stochastic Hipparcos Solutions
Authors: Arenou F.
Published: June 2021

The Hipparcos astrometric parameters were obtained through the merging of abscissae data obtained by the FAST and NDAC Data Reduction Consortia. Using a different reduction scheme, other astrometric solutions may be obtained, although not statistically different: a weighted solution using FAST and NDAC astrometric solutions is shown, which gives both astrometric data and associated covariance matrix. This is applied to the acceleration and stochastic solutions. The intersection between merged and weighted solutions is then studied from the point of view of the possible signature of astrometric binaries.

New astrometric binaries were found during the Hipparcos data reduction process and their orbits were determined or improved. Other astrometric binaries may however be detected by searching for a quasi-sinusoidal signaturein right ascension and declination. For this purpose the observations of the candidate stars have been combined at a few different epochs, using the Hipparcos astrometric intermediate data.

A simultaneous fit of the astrometric and orbital parameters has then been done. However in most of the cases other ground-based data is needed in order to confirm the suspected binarity and to give a reliable orbit.
Aperture Synthesis of Hipparcos Transit Data
Authors: Quist C.F. , Lindegren L. , Söderhjelm S.
Published: June 2021

The ESA Hipparcos astrometry satellite did not contain an imaging detector (such as a CCD) but used a modulating grid of alternating transparent and opaque bands to modulate the light from a given object. The Fourier coefficients of the modulated detector signal were the basis for the astrometric and photometric processing leading to the Hipparcos Catalogue. These coefficients are included (for a subset of the stars) in the CD-ROM version of the Hipparcos Catalogue as the ‘Hipparcos Transit Data’. In this work, the Transit Data are used in a completely different and novel application: the modulation components from a single scan are considered to be equivalent to the interference fringes from an interferometer oriented along the scan direction and having baselines of 0, ≃ 10 and ≃ 20 cm and a wavelength of 550 nm. Using all the scans collected over the mission lifetime, it is possible to use the complex visibilities (containing bothamplitude and phase information) calculated from the Transit Data to createaperture synthesis images of various type of objects such as visual or orbiting binary systems. More information, including sample images, can be found in: Quist C.F., Lindegren L., Söderhjelm S., 1997, Using HipparcosTransit Data for Aperture Synthesis Imaging, Hipparcos Venice ‘97 Symposium, ESA SP-402 (in press).
Hipparcos and Theory of Stellar Interiors
Authors: Baglin A.
Published: June 2021

The theory of stellar interiors is generally considered as well settled, and many branches of astrophysics rely on its results. However, the true situation is not so bright. Despite great successes at its beginning, in the sixties, it has to deal with many physical processes, generally poorly understood, which have large influences on the results and the derived quantities, like for instance ages.

After a rapid description of these difficulties, I will recall the majorquestions of the confrontation between theory and observations, and how HIPPARCOS can and will help. As an illustration, a few preliminary results will be presented, and future prospects foreseen. But, this short review is byno means exhaustive; there are many more results dealing directly or indirectly with stellar structure theory which have already been presented at theVenice Symposium (Perryman et al, 1997a), and many more, I am not aware of, will certainly appear soon.
Luminosity of δ Scuti Stars After Hipparcos Satellite
Authors: Antonello E. , Mantegazza L. , Poretti E.
Published: June 2021

The absolute magnitudes of δ Scuti stars derived from parallaxes measured by the Hipparcos satellite were compared with the previous estimates based on photometric uvby² indices, and significant differences were found which are related to photometric effects of metallicity and rotational velocity. A reliable calibration of Mv in terms of the photometric indices shall include an estimate of these effects. It is important also to take into account the possible presence of unresolved close companions in order to fully exploit the accuracy of Mv of nearby stars derived from the trigonometric parallaxes.

The Mv of few bright SX Phe stars support the period-luminosity relation obtained with ground based observations of globular clusters, while it does not seem to confirm the empirical dependence of this relation on the metallicity.

Some high amplitude δ Scuti stars with intermediate or normal metallicity and small and uncertain parallax have apparently a very low luminosity. Simulations of Mv determinations from observed parallaxes based on the discussion of observational errors by Lutz and Kelker (1973) have shown that the low luminosity could be an effect related to these errors.
A Search for Stars Passing Close to the Sun
Authors: Garcia-Sanchez J. , Preston R.A. , Jones D.L. , Weissman P.R. , Lestrade J.-F. , Latham D.W. , Stefanik R.P.
Published: June 2021

We have combined radial velocity measurements with Hipparcos proper motion and parallax data for 552 nearby stars of a selected sample of 1208 stars to find which stars may have passed (or will pass) close enough to the Sun to perturb the cometary Oort cloud. We find that the rate of close stellar approaches within a distance D (in pc) from the Sun is N = 4.3 D2.02 Myr-1 in excellent agreement with the predicted functional form of simple stellar dynamics models though the number of stars is less than predicted. However, we consider this a lower limit because there isevidence for observational incompleteness in our data set. One star (Gliese710) is found with a future closest approach of less than 0.4 pc, and several stars come within about 1 pc during about a ±10 Myr interval. We have performed dynamical simulations which show that none of the passing
stars in this sample can perturb the Oort cloud sufficiently to create a substantial increase in the long-period comet flux at the Earth’s orbit.
Concluding Remarks
Authors: Perryman M.A.C.
Published: June 2021

Seventeen years ago, the Hipparcos project was accepted within ESA’s scientific programme, as the first space mission specifically devoted to the accurate measurement of stellar positions. As the result of an unprecedented and productive collaboration between ESA and the European astronomical community, the Hipparcos project has reached a decisive milestone.

The Hipparcos and Tycho Catalogues were completed in August 1996, and made widely available in June 1997, when they were published by ESA as the 17-volume publication ESA SP-1136. Volume 17 includes all data files, and documentation, in the form of six ASCII CD-ROMs. The catalogues can be obtained from the ESA Publications Division, with full details (and an order form)given on the Hipparcos www page, http://astro.estec.esa.nl/Hipparcos. The full catalogues are also available via ftp from the CDS, Strasbourg, where the catalogue data are also linked to the cross-identifications in the SIMBAD data base, and through the VizieR relational data base queries.

The Hipparcos www page also supports remote interrogation of the catalogues, either by object (HIP or TYC) identifier, or via a search range in right ascension and declination. Active links allow the user to follow selected HIP or TYC identifiers, entering the associated annexes (Variability Annexes, and the Double and Multiple Systems Annex) or inspecting the light-curve (in PDF form) when provided. A more comprehensive search and interrogation facility will become available at the end of 1997 in the form of a CD-ROM (Celestia 2000) with access and display software prepared for IBM PC and compatibles running under Windows 3.1, Windows 95, or Windows NT.
Increasing access to brief Coping Strategy Enhancement for distressing voices: a service valuation exploring a possible role for briefly-trained therapists
Authors: Clarke Phil , Jones Anna-Marie , Hayward Mark
Published: June 2021

Hearing voices is a distressing and trans-diagnostic experience. Cognitive behavioural therapy (CBT) is an effective psychological treatment for distressing voices, but is offered to only a minority of patients. Limited resources are a barrier to accessing CBT. Evaluations of brief forms of CBT for voices have offered encouraging findings, but the ability of briefly-trained therapists to deliver these brief therapies has yet to be explored. We evaluated the outcomes of a brief form of CBT (Coping Strategy Enhancement, CSE) for voices when delivered by highly-trained and briefly-trained therapists. This was a service evaluation comparing pre–post outcomes in patients who had completed brief CSE over four sessions, within NHS Mental Health Services, delivered by highly-trained and briefly-trained therapists. The primary outcome was the negative impact scale of the Hamilton Program for Schizophrenia Voices Questionnaire. Data were available from 92 patients who completed a course of brief CSE – nearly half of whom received therapy from a briefly-trained therapist. Modest benefits across the sample were consistent with previous evaluations and did not seem to be influenced by the training of the therapist. This service evaluation offers further evidence that brief CSE can begin a therapeutic conversation about distressing voices within routine clinical practice. The usefulness of this initial conversation does not seem to be reliant upon the extent of therapist training, suggesting that briefly-trained therapists may play a role in increasing access to these conversations for patients distressed by hearing voices.

Key learning aims

(1)

How can access to CBT be increased for patients distressed by hearing voices?

(2)

Can a wider workforce of briefly-trained therapists start a CBT-informed conversation about distressing voices?

(3)

How do the outcomes of these conversations compare with the same conversations facilitated by highly trained therapists?
Stormwater Runoff and Tidal Flooding Transform Dissolved Organic Matter Composition and Increase Bioavailability in Urban Coastal Ecosystems
Authors: Smith Matthew A. , Kominoski John S. , Gaiser Evelyn E. , Price René M. , Troxler Tiffany G.
Published: June 2021

Coastal drainages contain multiple sources of dissolved organic matter (DOM) that influence OM transformation and fate along inland‐to‐marine gradients. Anthropogenic activities have altered DOM composition in urban drainages, thereby influencing in‐stream breakdown rates, primary productivity, and downstream export. Yet, it is uncertain how hydrologic conditions (i.e., rainfall, tides, shallow groundwater) interact with different sources of DOM to regulate the transformation and export of DOM through urban coastal drainages. We characterized how seasonal changes in hydrologic conditions influence DOM composition and bioavailability in tidally influenced drainages in Miami, FL, USA. We estimated the quality and bioavailability of DOM using compositional proxies based on fluorescence spectroscopy, including parallel‐factor analysis, and measured dissolved organic carbon degradation during laboratory incubations containing a local bacterial community. Interactions between stormwater runoff and tidal amplitude increased the bioavailability of DOM and were positively correlated with predominantly humic‐like components in the wet season and protein‐like components in the dry season. Further, increases in tryptophan fluorescence intensity corresponded with elevated concentrations of Escherichia coli and enterococci—likely from waste‐impacted groundwater—and contributed substantially to overall DOM bioavailability. Our results provide new evidence of an urban priming effect in which labile autochthonous DOM from anthropogenic sources facilitates microbial degradation of DOM that is driven by seasonal differences in stormwater runoff and tides. As hydrologic conditions in near‐shore aquatic ecosystems shift with urbanization and climate‐driven changes in sea‐level rise, increases in autochthonous sources of bioavailable DOM may impact ecosystem metabolism and affect the quality of DOM exported downstream.
Probabilistic Cover‐Basement Interface Map in Cloncurry, Australia, Using Magnetotelluric Soundings
Authors: Seillé Hoël , Visser Gerhard , Markov Jelena , Simpson Janelle
Published: June 2021

In this article we propose a workflow for creating geologically realistic depth to basement maps and apply it to the undercover area of Cloncurry, located in the Mount Isa province, Queensland. A magnetotelluric (MT) survey consisting of 457 soundings was inverted using a 1D trans‐dimensional Bayesian algorithm designed to be robust to non‐1D effects present in the data. Automated change‐point analysis was then used to derive probability distributions on basement depth for each site independently. These were laterally combined, along with drill hole data and a structural model derived from aeromagnetic and geological data, using a Bayesian estimate fusion algorithm to create a region wide depth to basement probabilistic map. Combining many different constraints in this way lead to a significant reduction in posterior uncertainty. Individual MT site change‐point posteriors were highly multi‐modal in certain areas, with multiple resistivity transitions that could correspond to the cover‐basement interface. The estimate fusion process correlates these uncertainties and the combined posterior was thus much less multi‐modal. Our results show that the sedimentary cover gradually thickens toward the north, while toward the east its thickening is controlled by a two‐steps fault system. This workflow highlights the value gained from integrating different types of geoscientific data but also shows the capability of the MT method used within a probabilistic workflow to accurately image depth to basement even using limited constraints and assumptions.
Quasi‐4‐Day Wave: Atmospheric Manifestation of the First Symmetric Rossby Normal Mode of Zonal Wavenumber 2
Authors: Yamazaki Y. , Matthias V. , Miyoshi Y.
Published: June 2021

This paper describes global characteristics of the westward‐propagating planetary wave with a period of ∼4 days and zonal wavenumber 2, here referred to as quasi‐4‐day wave (Q4DW), which is considered to be a manifestation of the (2,1) Rossby normal mode. A climatology of the Q4DW is derived from geopotential height measurements by the Aura Microwave Limb Sounder during August 2004–December 2020. In the mesosphere and lower thermosphere (MLT), amplitude maxima occur at mid latitudes in May and August in the Northern Hemisphere, and in February and November in the Southern Hemisphere. With the amplitude exceeding 300 m, the Q4DW sometimes becomes the dominant mode of traveling planetary waves in the MLT. The seasonal variation is largely determined by the zonal mean state. As predicted by previous modeling work, the amplitude grows rapidly with height on the equatorward side of the critical layer, where the zonal mean flow is weakly eastward relative to the wave. The wave growth can be particularly large when there is a region of unstable mean flow across the boundary of the critical layer. This condition is met not only during the seasonal amplification of the Q4DW but also during some Arctic sudden stratospheric warming events, leading to an unseasonal enhancement.
SIRT1 coordinates with the CRL4B complex to regulate pancreatic cancer stem cells to promote tumorigenesis
Authors: Leng Shuai , Huang Wei , Chen Yang , Yang Yang , Feng Dandan , Liu Wei , Gao Tianyang , Ren Yanli , Huo Miaomiao , Zhang Jingyao , Yang Yunkai , Wang Yan
Published: June 2021

Pancreatic cancer is a common malignant tumor with poor prognosis. Recently, cancer stem cells (CSCs) were identified in several solid tumors, including pancreatic cancer. Although accumulating evidence indicates that sirtuin 1 (SIRT1) exerts biological functions in various cancers, how it contributes to tumorigenesis and metastasis of pancreatic cancer, as well as its role in CSCs, is still poorly defined. Here we show that SIRT1 interacts with the Cullin 4B (CUL4B)-Ring E3 ligase (CRL4B) complex, which is responsible for H2AK119 monoubiquitination (H2AK119ub1), collaborating as a functional unit. Genome-wide analysis of SIRT1/CUL4B targets identified a cohort of genes, including GRHL3 and FOXO3, critically involved in cell differentiation, growth, and migration. Furthermore, we found that SIRT1 and CUL4B collectively promote the proliferation, autophagy, and invasion of pancreatic cancer cells. Remarkably, we demonstrate that SIRT1/CUL4B promotes CSC-like properties, including increased stemness marker expression and sphere formation. In vivo experiments implied that SIRT1 promoted established tumor xenograft growth, increased tumor-initiating capacity in NOD/SCID mice, and increased CSC frequency. Strikingly, SIRT1 and CUL4B expression is markedly upregulated in a variety of human cancers, including pancreatic cancer. Our data provide a molecular basis for the functional interplay between histone deacetylation and ubiquitination. The results also implicate the SIRT1/CRL4B complex in pancreatic cancer metastasis and stem cell properties, thus supporting SIRT1 as a promising potential target for cancer therapy development.