Archival Data Research Articles

An impressionist view of V Hydrae

Context. Asymptotic giant branch (AGB) stars enrich the interstellar medium through their mass loss. The mechanism(s) shaping the circumstellar environment of mass-losing stars is not clearly understood so far. Aims. Our purpose is to study the effect of binary companions located within the first 10 stellar radii from the primary AGB star. In this work, we target the mass-losing carbon star V Hydrae (V Hya) and search for signatures of its companion in the dust-forming region of the atmosphere. Methods. The star was observed in the L and N bands with the VLTI/MATISSE instrument at low spectral resolution. We reconstructed images of the photosphere and surroundings of V Hya using the two bands and compared our interferometric observables with VLTI/MIDI and VISIR archival data. To constrain the dust properties, we used the 1D radiative transfer code DUSTY to model the spectral energy distribution. Results. The star is dominated by dust emission in the L- and N-bands. The MATISSE reconstructed images show asymmetric and elongated structures in both infrared bands. In the L band, we detected an elongated shape of approximately 15 mas that likely is of photospheric origin. In the N band, we found a 20 mas extension northeast from the star and perpendicular to the L-band elongated axis. The position angle and the size of the N-band extension match the prediction of the companion position at the MATISSE epoch. By comparing MATISSE N-band with MIDI data, we deduce that the elongation axis in the N-band has rotated since the previous interferometric measurements 13 yr ago, supporting the idea that the particle enhancement is related to the dusty clump moving along with the companion. The VISIR image confirms the presence of a large-scale dusty circumstellar envelope surrounding V Hya. Conclusions. The MATISSE images unveil the presence of a dust enhancement at the position of the companion. This opens new doors for further analyses of the binary interaction with an AGB component.

Astrometric and photometric characterization of η Tel B combining two decades of observations

Context. η Tel is an 18 Myr system composed of a 2.09 M⊙ A-type star with an M7-M8 brown dwarf companion, η Tel B. The two objects have a projected separation of 4″.2 (~208 au). This system has been targeted by high-contrast imaging campaigns for over 20 yr, facilitating its orbital and photometric characterization. The companion, η Tel B, both bright and on a wide orbit, is an ideal candidate for a detailed examination of its position and the characterization of its atmosphere. Aims. To explore the orbital parameters of η Tel B, measure its contrast, and investigate its close surroundings, we analyzed three new SPHERE/IRDIS coronagraphic observations. Our objectives are to investigate the possibility of a circumplanetary disk or a close companion around η Tel B, and characterize its orbit by combining this new data set with archival data acquired in the past two decades. Methods. The IRDIS data are reduced with state-of-the-art algorithms to achieve a contrast with respect to the star of 1.0 × 10−5 at the location of the companion. Using the NEGative Fake Companion technique (NEGFC), we measure the astrometric positions and flux of η Tel B for the three IRDIS epochs. Together with the measurements presented in the literature, the baseline of the astrometric follow-up is 19 yr. Results. We calculate a contrast for the companion of 6.8 magnitudes in the H band. The separation and position angle measured are 4″.218 and 167.3 degrees, respectively. The astrometric positions of the companions are calculated with an uncertainty of 4 milliarc-seconds (mas) in separation and 0.2 degrees in position angle. These are the smallest astrometrical uncertainties of η Tel B obtained so far. The orbital parameters are estimated using the Orvara code, including all available epochs. The orbital analysis is performed taking into account the Gaia-HIPPARCOS acceleration of the system. Suppressing its point spread function (PSF), we have produced contrast curves centered on the brown dwarf in order to constrain our detection capabilities for a disk or companions around it. Conclusions. After considering only orbits that could not disrupt the outer debris disk around η Tel A, our orbital analysis reveals a low eccentric orbit (e ~ 0.34) with an inclination of 81.9 degrees (nearly edge-on) and a semi-major axis of 218 au. Furthermore, we determine the mass of η Tel B to be 48 MJup, consistent with previous calculations from the literature based on evolutionary models. Finally, we do not detect any significant residual pointing to the presence of a satellite or a disk around the brown dwarf. The retrieved detection limits allow us to discard massive objects around η Tel B with masses down to 1.6 MJup at a separation of 33 au.

Indian Dental Malpractice Claims and Lawsuits: A Medico-Legal Analysis.

The law of the land assumes that a dentist will always use credible skill, care, and caution in the care of patients. Failing to do something that one is supposed to do (act of omission) or doing something that one is not supposed to do (act of commission) falls under the purview of medical jurisprudence. Each patient is legally entitled to get quality medical care from a physician; failure to such trust is an actionable offense and grievances can be challenged in consumer redressal forums. This analytical study was aimed to study the reasons for dental negligence cases that sought judicial assistance in consumer courts in terms of monetary benefits and also to study the delay in settlements. Archival data of final court-pronounced judgment cases on dental negligence between 2018 and 2022 (i.e., 5 years) were gathered from customer forum websites (https://confonet.nic.in, http://indiankanoon.org/doc, and www.casemine.com). A total of 56 proven dental allegation cases were retrieved. In each verdict case, the allegation against dentist by the plaintiff was recorded, and the response to the complaint by the defendant was studied and analyzed. The year of filing the case and date of judgment, basis of compensation awarded, delay in judgment and role of expert evidence appointed by the court assessed. Misdemeanor by serious negligence: 3, slight negligence: 8, negligent injuries: 35, felony of injuries by serious negligence: 10. Because dentistry involves making decisions in unclear scenarios that affect patient care, there is an inherent danger of malpractice litigation. Awareness of medico-legal issues and professional indemnity insurance coverage for the dentist to safeguard himself from negligence, continuous medico-legal training and documentation of records, and adherence to clinical standards for procedures should be emphasized as prior motives to enhance the standard of care, and a basic awareness of how Indian courts resolve disputes would help dentists plan their professional indemnity insurance and operate their profession properly.

THE NARRATIVE IN T. KESKISARJA’S BOOK “THE WAR OF THE HATS”

The research is carried out within the framework of a narratological analysis, the material for which was T. Keskisarja’s military historical monograph “The War of the Hats.” Keskisarja’s work is a historical narrative with literary features. The narrative strategies implemented in the text are considered.The starting point of the research was the juxtaposition of historical and literary narratives, scientific and artistic styles. Keskisarja’s book is dedicated to the Russian-Swedish war of 1741–1743 (known as the War of the Hats), which Sweden began in the hope of regaining the territories lost during the Northern War (1700–1721).The scenes of the past are presented mainly through the decisions of military and civil courts, clergy records, various documents (letters, orders, petitions), historical maps. Keskisarja uses interpretation as the main tool for analyzing archival materials, which makes it possible to reason about human experience.The method used by Keskisarja to present archival data to the 21st-century reader through the prism of a novel with the features of a psychological analysis fully meets the needs of the present time. The fascinating manner of narration, combined with the historian’s professionalism gives the reader a completely adequate idea of the political situation in Europe and the tragic events of the 18th century.Keskisarja uses the expressive means of fiction, inserts a fictional, independent, third-party observer into the historical narrative — a “sentient being” who evaluates events and conducts a dialogue with the reader. Such features of the text under study as dialogicality, anthropocentricity, emotionality, and hybridity are noted. The details of the fates of real people give the narrative volume and expressiveness. The author of the monograph does not “invent” certain events of the described reality — he conjectures and interprets them, trying to discover their meaning, their connection with the past and the future.

The effects of stellar feedback on molecular clumps in the Lagoon Nebula (M8)

Context. The Lagoon Nebula (M8) is host to multiple regions with recent and ongoing massive star formation, due to which it appears as one of the brightest H II regions in the sky. M8-Main and M8 East, two prominent regions of massive star formation, have been studied in detail over the past few years, while large parts of the nebula and its surroundings have received little attention. These largely unexplored regions comprise a large sample of molecular clumps that are affected by the presence of massive O- and B-type stars. Thus, exploring the dynamics and chemical composition of these clumps will improve our understanding of the feedback from massive stars on star-forming regions in their vicinity. Aims. We established an inventory of species observed towards 37 known molecular clumps in M8 and investigated their physical structure. We compared our findings for these clumps with the galaxy-wide sample of massive dense clumps observed as part of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). Furthermore, we investigated the region for signs of star formation and stellar feedback. Methods. To obtain an overview of the kinematics and chemical abundances across the sample of molecular clumps in the M8 region, we conducted an unbiased line survey for each clump. We used the Atacama Pathfinder EXperiment (APEX) 12m submillimetre telescope and the 30 m telescope of the Institut de Radioastronomie Millimétrique (IRAM) to conduct pointed on-off observations of 37 clumps in M8. These observations cover bandwidths of 53 GHz and 40 GHz in frequency ranges from 210 GHz to 280 GHz and from 70 GHz to 117 GHz, respectively. Temperatures were derived from rotational transitions of acetonitrile, methyl acetylene, and para-formaldehyde. Additional archival data from the Spitzer, Herschel, MSX, APEX, WISE, JCMT, and AKARI telescopes were used to investigate the morphology of the region and to derive the physical parameters of the dust emission by fitting spectral energy distributions to the observed flux densities. Results. Across the observed M8 region, we identify 346 transitions from 70 different molecular species, including isotopologues. While many species and fainter transitions are detected exclusively towards M8 East, we also observe a large chemical variety in many other molecular clumps. We detect tracers of photo-dissociation regions (PDRs) across all the clumps, and 38% of these clumps show signs of star formation. In our sample of clumps with extinctions between 1 and 60 mag, we find that PDR tracers are most abundant in clumps with relatively low H2 column densities. When comparing M8 clumps to ATLASGAL sources at similar distances, we find them to be slightly less massive (median 10 M⊙) and have compatible luminosities (median 200 L⊙) and radii (median 0.16 pc). In contrast, dust temperatures of the clumps in M8 are found to be increased by approximately 5 K (25%), indicating substantial external heating of the clumps by radiation of the present O- and B-type stars. Conclusions. This work finds clear and widespread effects of stellar feedback on the molecular clumps in the Lagoon Nebula. While the radiation from the O- and B-type stars possibly causes fragmentation of the remnant gas and heats the molecular clumps externally, it also gives rise to extended PDRs on the clump surfaces. Despite this fragmentation, the dense cores within 38% of the observed clumps in M8 are forming a new generation of stars.

Emergence of high-mass stars in complex fiber networks (EMERGE)

Context. Recent molecular surveys have revealed the rich gas organization of sonic-like filaments at small scales (so-called fibers) in all types of environments prior to the formation of low- and high-mass stars. These fibers form at the end of the turbulent cascade and are identified as the fine substructure within the hierarchical nature of the gas in the interstellar medium (ISM). Aims. Isolated fibers provide the subsonic conditions for the formation of low-mass stars. This paper introduces the Emergence of high-mass stars in complex fiber networks (EMERGE) project, which investigates whether complex fiber arrangements (networks) can also explain the origin of high-mass stars and clusters. Methods. We analyzed the EMERGE Early ALMA Survey including seven star-forming regions in Orion (OMC-1,2,3, and 4 South, LDN 1641N, NGC 2023, and the Flame Nebula) that were homogeneously surveyed in three molecular lines (N2H+ J = 1–0, HNC J = 1–0, and HC3N J = 10–9) and in the 3 mm continuum using a combination of interferometric ALMA mosaics and IRAM-30 m single-dish (SD) maps, together with a series of Herschel, Spitzer, and WISE archival data. We also developed a systematic data reduction framework allowing the massive data processing of ALMA observations. Results. We obtained independent continuum maps and spectral cubes for all our targets and molecular lines at different (SD and interferometric) resolutions, and we explored multiple data combination techniques. Based on our low-resolution (SD) observations (30″ or ~12 000 au), we describe the global properties of our sample, which covers a wide range of physical conditions, including low-(OMC-4 South and NGC 2023), intermediate (OMC-2, OMC-3, and LDN 1641N), and high-mass (OMC-1 and Flame Nebula) star-forming regions in different evolutionary stages. The comparison between our single-dish maps and ancillary YSO catalogs denotes N2H+ (1–0) as the best proxy for the dense, star-forming gas in our targets, which show a constant star formation efficiency and a fast time evolution of ≲1 Myr. While apparently clumpy and filamentary in our SD data, all targets show a much more complex fibrous substructure at the enhanced resolution of our combined ALMA+IRAM-30 m maps (4″.5 or ~2000 au). A large number of filamentary features at subparsec scales are clearly recognized in the high-density gas (≳ 105 cm−3) that is traced by N2H+ (1–0) directly connected to the formation of individual protostars. Surprisingly, this complex gas organization appears to extend farther into the more diffuse gas (~103−104 cm−3) traced by HNC (1–0). Conclusions. This paper presents the EMERGE Early ALMA Survey, which includes a first data release of continuum maps and spectral products for this project that are to be analysed in future papers of this series. A first look at these results illustrates the need of advanced data combination techniques between high-resolution interferometric (ALMA) and high-sensitivity, low-resolution single-dish (IRAM-30 m) datasets to investigate the intrinsic multiscale, gas structure of the ISM.

Design and Application of an S-band Fast Radio Bursts Search Pipeline for the Nanshan 26 m Radio Telescope

Fast radio bursts (FRBs) are among the most studied radio transients in astrophysics, but their origin and radiation mechanism are still unknown. It is a challenge to search for FRB events in a huge amount of observational data with high speed and high accuracy. With the rapid advancement of the FRB research process, FRB searching has changed from archive data mining to either long-term monitoring of the repeating FRBs or all-sky surveys with specialized equipments. Therefore, establishing a highly efficient and high quality FRB search pipeline is the primary task in FRB research. Deep learning techniques provide new ideas for FRB search processing. We have detected radio bursts from FRB 20201124A in the L-band observational data of the Nanshan 26 m radio telescope (NSRT-26m) using the constructed deep learning based search pipeline named dispersed dynamic spectra search (DDSS). Afterwards, we further retrained the deep learning model and applied the DDSS framework to S-band observations. In this paper, we present the FRB observation system and search pipeline using the S-band receiver. We carried out search experiments, and successfully detected the radio bursts from the magnetar SGR J1935+2145 and FRB 20220912A. The experimental results show that the search pipeline can complete the search efficiently and output the search results with high accuracy.

Contemporary insights on corporate guidance: A discussion of Call, Hribar, Skinner, and Volant (2024)

Guidance is an important and long-studied topic in the accounting literature. Call, Hribar, Skinner, and Volant (this issue) survey managers who provide guidance and those that do not to generate insights on the costs and benefits of providing guidance. For managers who do provide guidance, perceptions regarding guidance characteristics are elicited. Firm responses are connected to archival data sources, enabling cross-sectional analysis of survey responses and facilitating comparison of self-reported guidance with common guidance proxies in the archival literature. I discuss key insights from the survey, considering the limitations inherent in the survey method. I also clarify what is meant by the term guidance, how it differs from other forward-looking information and how researchers operationalize the guidance construct. I conclude by offering six research questions for future consideration based on the survey evidence.

Money talks? The motivational mechanisms of base pay on well-being and work performance.

Whether compensation serves as a motivational resource for employees is still a debated subject. It has been suggested that the effect of pay on motivation could be contingent on the satisfaction of the basic psychological needs as outlined by self-determination theory. The current research explored the role of amount of base pay as well as pay fairness discrepancy in relation to basic psychological need satisfaction, autonomous work motivation and, in turn, psychological well-being (i.e., vigor and emotional exhaustion), turnover intentions, and work performance. Managerial need support was also included in the model, so its mechanisms and its effects on the outcomes could be measured against those of pay. Using a combination of archival data and employees' self-reports from 593 Norwegian workers, results revealed that amount of base pay did not predict satisfaction of any of the basic needs, pay fairness discrepancy negatively predicted satisfaction of the needs for autonomy and relatedness and positively predicted satisfaction of the need for competence, whereas managerial need support significantly predicted satisfaction of all three needs. While there was no significant direct relation from amount of base pay to any of the outcomes, results showed a significant direct relation from managerial need support to psychological well-being (positive to vigor and negative to emotional exhaustion)and turnover intentions (negative). There was also a significant direct positive relation from pay fairness discrepancy to turnover intentions.

FORCED DEPORTATION OF PEOPLES TO KAZAKHSTAN

The totalitarian system that dominated during the Soviet period forcibly displaced manynationalities and ethnic groups from their historical homeland, causing great damage to their unity andintegrity, cultural and social development, pursuing a policy of ideological arbitrariness (dictatorship).Soviet leaders forcibly deported to the territory of Central Asia, accusing the Crimean people of activecooperation with the German invaders in order to strengthen the central political power. The CrimeanPeninsula was the main tourist center of the USSR and one of the regions of high political importance.This scientific article, written on this basis, presents historical data on the state of the population onthe Crimean Peninsula before the deportation, on the change of names of cities in Crimea, on how theprocess of forced displacement was carried out, based on archival data. The detrimental consequencesof the forced displacement of peoples to the territory of Kazakhstan and the impact on the nationalcomposition of the Kazakh people are analyzed. In the second half of the 20th century, attempts bythe peoples of Crimea to return to their homeland, the socio-economic situation of the population afterresettlement to the territory of Kazakhstan, and their contribution to the modern development of Kazakhstanisociety were considered.During the actual study of the article, archival data were used. Historical scientific methods of analysisand synthesis of scientific data, historical and comparative analysis, classification, systematization,etc. were also used.

ЛИТЕРАТУРНЫЕ СВЯЗИ И ВЛИЯНИЕ АЗЕРБАЙДЖАНСКОЙ ДРАМАТУРГИИ НА УЗБЕКСКИЙ ТЕАТР В ХХ ВЕКЕ

This study examines the connection between Eastern dramaturgy and Uzbek theatre through the perspectives of thinkers, including Nizami, Bekhbudi, and Fitrat. Notable pioneers of Azerbaijani drama, such as M.F. Akhundov and G. Javid, play a significant role in this context. Special attention is given to G. Javid, whose works, such as "Sheyda", "Sheikh Senan", "Iblis", were successfully staged on the Uzbek stage in the 1920s. Research by scholars such as S. Aliyev and Sh. Turdyev underscores the broad popularity of G. Javid's works among the Uzbek people. Archive data and testimonies of Uzbek artists also highlight the important role of Azerbaijani drama in shaping the Uzbek theatrical scene. Furthermore, the study reflects the influence of scholars and artists from Azerbaijan on the local theatrical and literary arts through their presence in educational institutions in Uzbekistan.`

Reconstruction of the paleotemperature of the Central Yakutia Ice Complex during the Holocene period

The increase in worldwide temperatures is leading to changes in permafrost landscapes in disturbed areas, which are causing the onset of cryogenic processes. Central Yakutia has a high population density and human impact on the permafrost, which contribute to the widespread occurrence of these processes. Studying the changes in permafrost over past periods is crucial for predicting future landscape changes, monitoring soil temperature changes in current warming conditions, and evaluating the stability of the upper permafrost layer. We reconstructed the temperature regime of the soils in the Ice Complex using mathematical modeling based on the chronology of climate evolution in Central Yakutia during the Holocene. Mathematical modeling of the temperature regime of the ice complex’s soils is based on climatic and thermophysical characteristics of the soils selected from the lithological sections of Central Yakutia. Archive data from weather stations was used for the analysis and sampling of climatic characteristics such as average annual and monthly air temperatures and snow cover thickness. During periods of warming, the calculated ground temperatures at the depth of zero heat turnover were between –2.1 and –2.7 °C, showing a difference of 0.4–1 °C from the current temperatures. Conversely, during cooling periods, the temperatures ranged from –5.2 to –12.3 °C, with a variance of 2.1–9.2 °C from the current soil temperatures. Thus, the examination of computational models indicates that the thermal conditions of the soils within the Ice Complex in Central Yakutia during the most significant periods of the Holocene are impacted by the thickness of the snow cover and the integrity of the Ice Complex.

Can E-Government Influence Well-Being? An Empirical Investigation

ABSTRACT While electronic government (e-government) is conceived as an innovative digital tool to bring economic and social benefits to a country, it remains largely underexplored whether it could help citizens have a meaningful, thriving, and happy life. A country’s development does not just depend on its economic performance or GDP; it is also contingent on the well-being of its citizens. Nevertheless, the literature lacks a theoretical and empirical understanding of the linkage between e-government and well-being. To fill this gap, this cross-country study examines (a) the direct influence of e-government maturity on well-being and (b) the mediating role of corruption perception, education, healthy life expectancy, and inequality in the above relationship. Hypotheses were tested using archival data from 123 countries. The results suggest that a higher level of e-government maturity in a country directly contributes to its well-being and indirectly by influencing corruption perception and healthy life expectancy.

Isotope dilution with isotopically labeled biomass: An effective alternative for quantitative metabolomics

BackgroundState-of-the-art quantitative metabolomics relies on isotope dilution using internal standards (IS) derived from fully 13C labeled biomass. By spiking samples and external standards with known amounts of IS, the spike characterization demands are kept to a minimum. In fact, it is sufficient to experimentally assess the isotopic enrichment of the IS. This study develops the yeast derived IS toolbox further, (1) by characterizing the concentration levels of hydrophilic metabolites in a yeast fermentation batch and (2) by exploring the analytical figures of merit of one-point IS versus multipoint external calibration using IS, the established gold-standard for quantitative metabolomics. ResultsIndependent reverse isotope dilution experiments using different chromatographic methods over a period of several months, delivered a list of 83 13C-labeled metabolites with fully characterized concentration and their uncertainty, covering 5 orders of magnitude, from the nanomolar to the low millimolar range. The 13C-labeled yeast-derived IS showed excellent intermediate stability with 92 % of molecules showing inter-method RSDs ≤30 % (75 % of molecules showed RSDs ≤15 %) over a timeframe of five months. One-point internal standardization with the characterized labeled biomass achieved figures of merit equivalent to multipoint calibrations for the majority of metabolites. SignificanceThe proposed calibration workflow rationalizes time and standard expenditure and is particularly beneficial for laboratories dealing with wide-target assays and small analysis batches. The present assessment serves as a seminal study for further developments of the concept towards absolute quantification from archive high-resolution MS data of U13C-biomass-spiked samples and the implementation of quick biomass recalibration with each experiment, promising seamless transition between internal standards derived from different fermentation batches.

ASSESSMENT OF THE POSSIBILITIES OF USING SACRED SITES AND THE NATURAL AND RECREATIONAL POTENTIAL OF THE NORTH KAZAKHSTAN REGION FOR THE FORMATION OF TOURIST ROUTES

To analyze the potential of sacred places as well as natural and recreational objects within the borders of the North Kazakhstan region of the Republic of Kazakhstan in the development of complex tourist routes. We examined archival data and documents and assessed the results of a sociological survey using statistical and mathematical processing, with tourist routes mapped out. The material under analysis and the results of the sociological survey enabled us to evaluate the touristic appeal and relevance of sacred places, as well as that of natural and recreational objects, in the North Kazakhstan region. A number of complex routes characterized by cultural, historical, pilgrimage, archeological, and environmental diversity were proposed. The cartographic material at hand enabled us to display a spatial plan of routes and accurately reflect the development potential of the region's tourism sector. The land of North Kazakhstan has the potential to expand the tourism industry. The demonstrated sacred places and diverse natural sites enable the creation of complex routes. We assessed the sacred places’ properties and determined the degree of attractiveness exhibited by complex routes, thus confirming the tourist opportunities offered by the region. These routes were designed to promote various directives such as historical, patriotic, and cultural education, natural world exploration, pilgrimage, spiritual awakening, and archaeology. Their use will contribute to the preservation of cultural and historical values, the expansion of international and domestic relations, and the developmen t of the economy and sustainability in the region. Skillful management in planning complex tourist routes in the North Kazakhstan region will facilitate the strengthening of ties between different communities and cultures, which is of great relevance for the multinational and multicultural country that is Kazakhstan.

Atmospheric Escape From Earth and Mars: Response to Solar and Solar Wind Drivers of Oxygen Escape

AbstractHabitability at the surface of a planet depends on having an atmosphere long enough for life to develop. The loss of atmosphere to space is an important component in assessing planetary surface habitability. Current models of atmospheric escape from exoplanets are not well constrained by observations. Atmospheric escape observations from the terrestrial planets are available in public data archives. We recast oxygen escape rates from Earth derived from an instrument on Dynamics Explorer‐1 as function of solar wind and compare them to similar data from Mars. Analysis demonstrates that oxygen escape rates from Mars are not as sensitive to variations in solar power components as those from Earth. Available data from Venus can confirm or refute the assertion that oxygen escape from magnetized planets is more sensitive than that from unmagnetized planets.

The role of Fe(II)-silicate gel in the generation of Archean and Paleoproterozoic chert

Abstract Chert is abundant in Archean and Paleoproterozoic rocks and is commonly densely packed with authigenic Fe(II)-silicate nanoparticles such as greenalite, indicating a close relationship between iron and silica deposition. We investigate the relationship between Fe(II)-silicate minerals and dissolved silica during precipitation, settling, and diagenesis using anoxic synthesis, sorption, and heating experiments. Excess silica is associated with the solid during precipitation, resulting in high molar Si/Fe ratios (<1.52) that exceed that of stoichiometric greenalite (0.67). At pH 8–8.5, silica sorbs to the surface, reaching sorption densities of 0.68 mmol Si per mmol Fe(II)-silicate. Furthermore, excess Si is released upon heating as the Fe(II)-silicate gel crystallizes. We suggest that Fe(II)-silicate minerals acted as an effective Si shuttle between the water column and the sediments in Archean and Paleoproterozoic marine environments, providing sites for the growth of early diagenetic chert, consistent with observations from the sedimentary record. Our results explain the exceptional preservation of greenalite in early chert and indicate that these minerals could provide a robust archive of marine geochemical data.

A VLITE Search for Millisecond Pulsars in Globular Clusters: Discovery of a Pulsar in GLIMPSE-C01

We present results from a search for pulsars in globular clusters, including the discovery of a new millisecond pulsar in the stellar cluster GLIMPSE-C01. We searched for low-frequency radio sources within 97 globular clusters using images from the VLA Low-band Ionosphere and Transient Experiment (VLITE) and epochs 1 and 2 of the VLITE Commensal Sky Survey. We discovered 10 sources in our search area, four more than expected from extragalactic source counts at our sensitivity limits. The strongest pulsar candidate was a point source found in GLIMPSE-C01 with a spectral index ∼ − 2.6, and we present additional measurements at 0.675 and 1.25 GHz from the GMRT and 1.52 GHz from the VLA that confirm the spectral index. Using archival Green Bank Telescope S-band data from 2005, we detect a binary pulsar with a spin period of 19.78 ms within the cluster. Although we cannot confirm that this pulsar is at the same position as the steep-spectrum source using the existing data, the pulse flux is consistent with the predicted flux density from other frequencies, making it a probable match. The source also shows strong X-ray emission, indicative of a higher magnetic field than most millisecond pulsars, suggesting that its recycling was interrupted. We demonstrate that low-frequency searches for steep-spectrum sources are an effective way to identify pulsar candidates, in particular on sightlines with high dispersion.

Resolved properties of a luminous hinge clump in the compact group of galaxies NGC 6845

Context. Compact groups of galaxies are unique places where galaxy-galaxy interactions play a mayor role on the evolution of its members. These strong gravitational encounters can induce star formation bursts. Aims. We study the properties of one of the most luminous so-called hinge clumps that is located in the compact group of galaxies NGC 6845. Methods. Using integral field spectroscopy from GMOS/Gemini complemented with archival MUSE data, we obtained oxygen abundances, ages, star formation rates, and velocity fields, and we also modeled a single stellar population to understand the star formation history of the hinge clump in NGC 6845. Results. We found that the hinge clump sits in a tailthat has a star formation rate of 3.4 M⊙ yr−1, which is comparable with a few other extreme cases, for instance, the star clusters in the Antennae galaxy and other reported hinge clumps in the literature. This clump represents ∼15% of total star formation rate of NGC 6845A. Large-scale modeling of the observed velocity field of NGC 6845A rules out the scenario according to which this hinge clump was a satellite galaxy. Its kinematics is compatible with that of the galactic disk of NGC 6845A. Its abundance with a mean value of 0.4 Z⊙ is also consistent with the metallicity gradient of the galaxy. Conclusions. Our analysis suggest that the hinge clump is formed by multiple stellar populations and not by a single burst. This causes the wide age range. We found that the central clump is encompassed by a ring-like structure, which might suggest a second generation of star formation. In addition, the analysis of the diagnostic diagram indicates that this central region might also be ionized by shocks from stellar and supernova winds. Finally, the derived star formation rate density Σ = 9.7 M⊙ yr−1 kpc−2 of the central clump places it in starburst regime, where gas inflows should provide gas to maintain the star formation. This work shows a resolved example of an extreme localized starburst in a compact group of galaxies.

Do symptoms and signs of temporomandibular disorders have an association with breathing pattern: a cross-sectional study on Turkish children and adolescents

BackgroundThis paper aimed to explore the prevalence of temporomandibular disorders (TMDs) signs/symptoms, and to investigate the possible link between signs/symptoms of TMDs and mouth breathing (MB) by evaluating along with other risk factors, in a Turkish subpopulation of children and adolescence.MethodsThis study was conducted with the archival data of the patients who applied with orthodontic complaints. Data on demographic characteristics, family-related factors, systemic status, occlusion, breathing patterns, oral habits, and bruxism were retrieved from the archival records.ResultsNine hundred forty-five children and adolescents with a mean age of 14.82 ± 2.06 years were included in the study. Of the participants, 66% were girls, 60.4% were delivered by C-section, 8.4% of the participants had at least one systemic disease, 9.2% of the participants had allergy, and 4.3% of the participants’ parents were divorced, 18.7% have an oral habit, 6.6% have bruxism, 29.8% have malocclusion and 14.1% have MB. Eight-point-five percent of participants have signs/symptoms of TMD. Among them 2.9% have pain, 3.7% have joint sounds, 1.4% have deflection, and 3.9% have deviation. Evaluation of the risk factors revealed a significant relation between the signs/symptoms of TMD and bruxism (OR 8.07 95% CI 4.36–14.92), gender (OR 2.01 95% CI 1.13–3.59), marital status of parents (OR 2.62 95% CI 1.07–6.42), and MB (OR 3.26 95% CI 1.86–5.71).ConclusionsAccording to the study’s findings, girls and those with bruxism, divorced parents, and MB behavior are more likely to have signs/symptoms of TMD. Age found to have significant effect on the occurrence of the signs/symptoms of TMD alone, but together with other factors the effect of the age is disappeared. Early screening and intervention of MB as well as the signs/symptoms of TMD can help to limit detrimental effects of these conditions on growth, and quality of life of children and adolescents.