Search

Objective: To describe the evolution of physical activity (PA) research in Africa, examine income and gender inequalities, and discuss future possibilities. Methods: A secondary analyses of the Global Observatory for Physical Activity data on PA research in Africa (1950–2019). Results: We identified 514 PA articles from 47 African countries in the past 70 years. Majority (83.1%) of the articles were published between 2012 and 2019. Fifteen countries had no publications. Six countries (South Africa [n = 156], Nigeria [n = 85], Ethiopia [n = 44], Ghana [n = 41], Kenya [n = 39], and Cameroon [n = 20]) accounted for about 75% of the publications. Most articles were observational (92.4%), single-country studies (78.4%), with male first (58.4%) and last authors (68%), and were classified as surveillance studies (45.1%). Few studies addressed interventions (5.8%) and policy (3.5%) or used device-based PA measurement (14.0%). The number of articles per country was positively related to human population level (r =.552, P =.000) and gross domestic product % spent on research and development (r =.301, P =.040). The publication rate per 100,000 people was positively related with the human development index (r =.349, P =.016) and negatively with the gender inequality index (r = −.360, P =.019). Conclusions: Our results provide an overview and status of PA research in Africa, highlighting country differences and gender inequalities in authorship. The findings may be used to benchmark the evolution of research in the region and to inform areas for improvement. There is an urgent need for more PA interventions and policy studies in Africa. [ABSTRACT FROM AUTHOR]

Very few detections have been made of optical flashes contemporaneous with prompt high-energy emission from a gamma-ray burst (GRB). In this work, we present and analyze light curves of GRB-associated optical flashes and afterglows from the Transiting Exoplanet Survey Satellite (TESS). Our sample consists of eight GRBs with arcsecond-level localizations from the X-Ray Telescope on board the Neil Gehrels Swift Observatory (Swift). For each burst, we characterize the prompt optical emission and any observed afterglow, and constrain physical parameters for four of these bursts using their TESS light curves. This work also presents a straightforward method to correct for TESS's cosmic-ray mitigation strategy on 20 s timescales, which allows us to estimate the "true" brightness of optical flashes associated with prompt GRB emission. We also highlight TESS's continuous wide-field monitoring capability, which provides an efficient means of identifying optical emission from GRBs and characterizing early time afterglow light curves. Based on empirical detection rates from Swift and the Fermi Gamma-ray Space Telescope, up to 10 GRBs per year may fall within the contemporaneous TESS field of view. [ABSTRACT FROM AUTHOR]

Gamma-ray burst (GRB), GRB 221009A, a long-duration GRB, was observed simultaneously by the Water Cherenkov Detector Array (WCDA) and the Kilometer Squared Array (KM2A) of the Large High Altitude Air Shower Observatory (LHAASO) during the prompt emission and the afterglow periods. Characteristic multi-TeV photons up to 13 TeV were observed in the afterglow phase. The observed very high-energy (VHE) gamma-ray spectra by WCDA and KM2A during different time intervals and in different energy ranges can be explained very well in the context of the photohadronic model with the inclusion of extragalactic background light models. In the photohadronic scenario, interaction of high-energy protons with the synchrotron self-Compton (SSC) photons in the forward shock region of the jet is assumed to be the source of these VHE photons. The observed VHE spectra from the afterglow of GRB 221009A are similar to the VHE gamma-ray spectra observed from the temporary extreme high-energy peaked BL Lac (EHBL), 1ES 2344+514 only during the 11th and the 12th of August, 2016. Such spectra are new and have been observed for the first time in a GRB. [ABSTRACT FROM AUTHOR]

Emerging active regions are associated with convective flows on the spatial scale and lifetimes of supergranules. To understand how these flows are involved in the formation of active regions, we aim to identify where active regions emerge in the supergranulation flow pattern. We computed supergranulation scale flow maps at the surface for all active regions in the Solar Dynamics Observatory Helioseismic Emerging Active Region Survey. We classified each of the active regions into four bins based on the amplitude of their average surface flow divergence at emergence. We then averaged the flow divergence over the active regions in each bin as a function of time. We also considered a corresponding set of control regions. We found that, on average, the flow divergence increases during the day prior to emergence at a rate independent of the amount of flux that emerges. By subtracting the averaged flow divergence of the control regions, we found that active region emergence is associated with a remaining converging flow at 0.5–1 d prior to emergence. This remnant flow, |$\Delta \, \mathrm{div} \, \boldsymbol {v}_{\rm h} = (-4.9 \pm 1.7) \times 10^{-6}\,{\rm s}^{-1}$|⁠ , corresponds to a flow speed of 10–20 m s−1 (an order of magnitude less than supergranulation flows) out to a radius of about 10 Mm. We show that these observational results are qualitatively supported by simulations of a small bipole emerging through the near-surface convective layers of the Sun. The question remains whether these flows are driving the emergence, or are caused by the emergence. [ABSTRACT FROM AUTHOR]

Next-generation gravitational wave (GW) observatories are expected to measure GW signals with unprecedented sensitivity, opening new, independent avenues to learn about our Universe. The distance–redshift relation is a fulcrum for cosmology and can be tested with GWs emitted by merging binaries of compact objects, called standard sirens, thanks to the fact that they provide the absolute distance from the source. On the other hand, fluctuations of the intervening matter density field induce modifications on the measurement of luminosity distance compared to that of a homogeneous universe. Assuming that the redshift information is obtained through the detection of an electromagnetic counterpart, we investigate the impact that lensing of GWs might have in the inference of cosmological parameters. We treat lensing as a systematic error and check for residual bias on the values of the cosmological parameters. We do so by means of mock catalogues of bright siren events in different scenarios relevant to the Einstein Telescope. For our fiducial scenario, the lensing bias can be comparable to or greater than the expected statistical uncertainty of the cosmological parameters, although non-negligible fluctuations in the bias values are observed for different realizations of the mock catalogue. We also discuss some mitigation strategies that can be adopted in the data analysis. Overall, our work highlights the need to model lensing effects when using standard sirens as probes of the distance–redshift relation. [ABSTRACT FROM AUTHOR]

Reprocessed X-ray radiation from active galactic nuclei (AGN) carries important information about the properties of the circumnuclear material around the black hole. The X-ray photons travel from the very centre of the system and interact with that material often producing strong emission lines. The |$\rm {Fe\, K\alpha }$| Compton shoulder (CS) is formed by fluorescent |$\rm {Fe\, K\alpha }$| photons that perform Compton scatterings with the intercepting material and lose energy to form the distinct shoulder shape. In this work, we use the ray-tracing code RefleX to explore how the physical properties of the medium, as well as its geometry, affect the shape of the CS. We start by running simulations using a simple toroidal reflector, to test the effect of the metal composition, metallicity, column density, dust presence and velocity on the |$\rm {Fe\, K\alpha }$| line, and its CS. We confirm that the shape of the CS is sensitive to the optical depth of the intercepting medium, which can be regulated by either changing the metal composition or the line-of-sight column density of the circumnuclear material. Next, we create a series of models, which feature different geometrical configurations of dust and gas, and explore how the CS is affected by such configurations finding that components that can regulate the line-of-sight column density affect the |$\rm {Fe\, K\alpha }$| and its CS. Finally, we test whether observatories such as the recently launched XRISM and future Athena will make the CS a useful spectral feature of nearby AGN, by applying specific models on simulated spectra of the Circinus galaxy. The CS has the potential to be used to help constrain properties of the circumnuclear material yet with some limitations. [ABSTRACT FROM AUTHOR]

The launches of NASA Kepler and Transiting Exoplanet Survey Satellite (TESS) missions have significantly enhanced the interest in the exoplanet field during the last 15 yr, providing a vast amount of public data that are being exploited by the community thanks to the continuous development of new analysis tools. However, using these tools is not straightforward, and users must dive into different codes, input–output formats, and methodologies, hindering an efficient and robust exploration of the available data. We present the sherlock pipeline, an end-to-end public software that allows the users to easily explore observations from space-based missions such as TESS or Kepler to recover known planets and candidates issued by the official pipelines and search for new planetary candidates that remained unnoticed. The pipeline incorporates all the steps to search for transit-like features, vet potential candidates, provide statistical validation, conduct a Bayesian fitting, and compute observational windows from ground-based observatories. Its performance is tested against a catalogue of known and confirmed planets from the TESS mission, trying to recover the official TESS Objects of Interest (TOIs), explore the existence of companions that have been missed, and release them as new planetary candidates. sherlock demonstrated an excellent performance, recovering 98 per cent of the TOIs and confirmed planets in our test sample and finding new candidates. Specifically, we release four new planetary candidates around the systems WASP-16 (with P |$\sim$|  10.46 d and R |$\sim$|  2.20 |$\mathrm{ R}_{\oplus }$|⁠), HAT-P-27 (with P |$\sim$|  1.20 d and R |$\sim$|  4.33 |$\mathrm{ R}_{\oplus }$|⁠), HAT-P-26 (with P |$\sim$|  6.59 d and R |$\sim$|  1.97 |$\mathrm{ R}_{\oplus }$|⁠), and TOI-2411 (with P |$\sim$|  18.75 d and R |$\sim$|  2.88 |$\mathrm{ R}_{\oplus }$|⁠). [ABSTRACT FROM AUTHOR]

This paper primarily investigates the effect of the tilt of corner cube reflector (CCR) arrays on lunar laser ranging (LLR). A mathematical model was established to study the random errors caused by the tilt of the CCR arrays. The study found that, ideally, when the laser ranging pulse width is 10 picoseconds or less, it is possible to distinguish from which specific corner cubes within the CCR array each peak in the echo signal originates. Consequently, partial data from the echo can be extracted for signal processing, significantly reducing random errors and improving the single-shot precision of LLR. The distance obtained by extracting part of the echo can be reduced to the center position of the array, thereby providing multiple higher-precision ranging results from each measurement. This not only improves the precision of LLR but also increases the data volume. A simulation experiment based on the 1.2 m laser ranging system at Yunnan Observatories was conducted. By extracting one peak for signal processing, the single-shot precision improved from 32.24 mm to 2.52 mm, validating the theoretical analysis results. Finally, an experimental laser ranging system based on a 53 cm binocular telescope system was established for ground experiments. The experimental results indicated that the echo signal could identify the tilt state of the CCR array. By extracting the peak returned by the central CCR for signal processing, the ranging precision was greatly improved. Through theoretical analyses, simulation experiments, and ground experiments, a solution to reduce the random errors caused by the tilt of the CCR array was provided. This offers an approach to enhance the single-shot precision of future LLR and provides a reference for upgrading ground-based equipment at future laser ranging stations. [ABSTRACT FROM AUTHOR]

The study analyzed available data series of the Sava River's water temperature measured at the Zagreb gauging station. Official data from the Croatian Meteorological and Hydrological Service (DHMZ) in Zagreb were utilized. Over the 73 years from 1948 to 2020, there are only 53 years with complete measurement records. Despite this limiting fact, it was considered important to analyze the behavior of the Sava River's water temperatures in Zagreb over the past 70 years, during which a significant increase in air temperatures has been observed in the region, particularly in the city of Zagreb. Analyses were conducted on the characteristic (minimum, mean, and maximum) water temperatures over timescales of years, months, and days. The relationship between water temperatures (TW) and air temperatures (TA) measured at the Grič Observatory and the flows (Q) of the Sava River in Zagreb were investigated. A trend of rising water temperatures was observed throughout the entire period from 1948 to 2020, with the intensity significantly increasing in the recent period starting from 1988. The trend of rising air temperatures is the primary driver of the increase in the water temperatures of the Sava River in Zagreb. However, the impact of reduced water flow, especially during the warm season, should not be overlooked. This effect is amplified by the observed trend of decreasing minimum flows of the Sava during the warm season, from June to September. As a result, the most significant rise in water temperatures of the Sava River in Zagreb occurs during prolonged low-water summer periods, particularly in July. A strong trend has been observed in the increasing number of days per year with mean daily water temperatures of the Sava River exceeding 20 °C. This higher water temperature occurs increasingly earlier in the year, lasts longer, and ends later, often extending into September. [ABSTRACT FROM AUTHOR]

A survey of British newspapers has uncovered 41 sightings of sunspots made by untrained people with no optical aid and without prompting. These truly accidental sightings mirror historical (pre-telescopic) western cases where there is no evidence of deliberate, intentional sunspot observation. The survey covered the period since 1874, when the Royal Observatory in Greenwich began compiling daily ledgers of sunspot sizes and positions from photoheliographic observations. This paper explains how candidate press reports were identified and then screened using objective criteria, and presents key results, in particular the circumstances under which the sightings were made, the sizes of the spots concerned, and indicators of solar activity (sunspot count, recurrence, geomagnetic storms) at the time. The survey found that 88 per cent of the accidental sightings were of sunspot groups whose whole spot projected areas exceeded 2,500 millionths of the visible solar disc, much greater than the 1,000 millionths usually quoted as a threshold for visual acuity. Furthermore, a spot 34,000 millionths in area was 100 times more likely to be noticed by accident than one with an area of 1,000-<2,000 millionths. Nearly all the accidental sightings were of recurrent groups and the associated mean sunspot number was >200. The possible implications of the results for the interpretation of historical sunspot reports are discussed. [ABSTRACT FROM AUTHOR]

Motivation Software plays a crucial and growing role in research. Unfortunately, the computational component in Life Sciences research is often challenging to reproduce and verify. It could be undocumented, opaque, contain unknown errors that affect the outcome, or be directly unavailable and impossible to use for others. These issues are detrimental to the overall quality of scientific research. One step to address this problem is the formulation of principles that research software in the domain should meet to ensure its quality and sustainability, resembling the FAIR (findable, accessible, interoperable, and reusable) data principles. Results We present here a comprehensive series of quantitative indicators based on a pragmatic interpretation of the FAIR Principles and their implementation on OpenEBench, ELIXIR's open platform providing both support for scientific benchmarking and an active observatory of quality-related features for Life Sciences research software. The results serve to understand the current practices around research software quality-related features and provide objective indications for improving them. Availability and implementation Software metadata, from 11 different sources, collected, integrated, and analysed in the context of this manuscript are available at https://doi.org/10.5281/zenodo.7311067. Code used for software metadata retrieval and processing is available in the following repository: https://gitlab.bsc.es/inb/elixir/software-observatory/FAIRsoft_ETL. [ABSTRACT FROM AUTHOR]

The article studies variation in the serpentine emission carrier frequency fSE observed in the 0.1–5.0 Hz frequency range under quiet magnetosphere conditions (Kp ~ 0–2). The data of magnetic field recording at the Antarctic Vostok Observatory (corrected geomagnetic coordinates Φ′ = −85.41°, Λ′ = 69.01°) for 1970‒1972 were used in the analysis. Using the dynamic spectra of ULF emission, we analyzed 90 cases of serpentine emission observation, the center carrier frequency of which gradually decreased (several times, sometimes to 0), then increased almost to the initial level in time intervals significantly exceeding the maximum modulation period (1 h). In this case, typical modulation of the emission carrier frequency with periods of 1–60 min persisted. The most likely time of observation of the detected effect was in the hours before midnight. It is shown that a decrease and subsequent increase in fSE were observed versus weak geomagnetic activity and relative stability of the dominant number of solar wind and IMF parameters. Taking into account the discovered synchronous coincidence of the behavior of fSE and dynamics of the AE-index, as well as observation of the effect of a decrease in the carrier frequency near local midnight, it is suggested that serpentine emission is most likely excited near the polar cusp, then penetrates the polar cap region. The behavior of fSE observed over long time intervals is presumably governed by the plasma parameter β and ratio of the proton density to the helium ion density Np/Na, the dynamics of which are similar to the average variation in fSE. [ABSTRACT FROM AUTHOR]

Marine microbial communities differ genetically, metabolically, and ecologically according to their lifestyle, and they may respond differently to environmental changes. In this study, we investigated the seasonal dynamics of bacterial assemblies in the free‐living (FL) and particle‐associated (PA) fractions across a span of 6 years in the Blanes Bay Microbial Observatory in the Northwestern Mediterranean. Both lifestyles showed marked seasonality. The trends in alpha diversity were similar, with lower values in spring–summer than in autumn‐winter. Samples from both fractions were grouped seasonally and the percentage of community variability explained by the measured environmental variables was comparable (32% in FL and 31% in PA). Canonical analyses showed that biotic interactions were determinants of bacterioplankton dynamics and that their relevance varies depending on lifestyles. Time‐decay curves confirmed a high degree of predictability in both fractions. Yet, 'seasonal' Amplicon Sequence Variants (ASVs) (as defined by Lomb Scargle time series analysis) in the PA communities represented 46% of the total relative abundance while these accounted for 30% in the FL fraction. These results demonstrate that bacteria inhabiting both fractions exhibit marked seasonality, highlighting the importance of accounting for both lifestyles to fully comprehend the dynamics of marine prokaryotic communities. [ABSTRACT FROM AUTHOR]

We present an analysis of high-dispersion spectroscopic observations of the symbiotic system R Aquarii (R Aqr) obtained with the Manchester Echelle Spectrograph at the 2.1-m telescope of the San Pedro Mártir Observatory (Mexico) in conjunction with available narrow-band images. The data are interpreted by means of the shape software to disclose the morpho-kinematics of the nebulosities associated with R Aqr. The model that best reproduces narrow-band images and position–velocity diagrams consists of three structures: an outer (large) hourglass structure surrounding an inner bipolar with a spiral-like filament entwined around the latter. The expansion velocity pattern of each structure is defined by different homologous expansion laws, which correspond to kinematic ages of |$\tau _1$|  = 450 |$\pm$|  25 yr (outer hourglass), |$\tau _2$|  = 270 |$\pm$|  20 yr (inner bipolar), and |$\tau _3$|  = 285 |$\pm$|  20 yr (spiral-like filament). We suggest that the spiral-like filament is tracing the regions of the interaction of a precessing jet with the circumstellar material, which simultaneously carves the inner bipolar structure. If a similar process created the large hourglass structure, it means that the action of the jet ceased for about 170 yr. We discuss the implications for other unresolved symbiotic systems detected in X-rays. [ABSTRACT FROM AUTHOR]

Extreme mass ratio inspirals (EMRIs) are one of the primary targets for the recently adopted millihertz gravitational-wave observatory LISA. Some previous studies have argued that a fraction of all EMRIs form in matter-rich environments, and can potentially explain the dozens of soft X-ray band (⁠|$\sim 10^{-1}\,\rm keV$|⁠), low-frequency (⁠|$\sim 0.1$| mHz) periodic phenomena known as quasi-periodic eruptions (QPEs) and quasi-periodic oscillations (QPOs). Here, using a representative EMRI population retrofitted with cutoffs on LISA-band SNRs and luminosity distances to account for the sensitivity of current instruments, we estimate the mean frequency band in which QPEs and QPOs originating from detectable LISA EMRIs may be emitting an X-ray signal 'today' (i.e. in 2024) to be |$0.46 \pm 0.22$| mHz. We also model the well-known QPO source, RE J1034+396, which falls in this frequency band, as an EMRI assuming its primary black hole mass to be |$10^6{-}10^7 \,{\rm M}_\odot$|⁠. Through a prior-predictive analysis, we estimate the orbiting compact object's mass to be |$46^{+ 10}_{-40} \,{\rm M}_\odot$| and the source's LISA-band SNR as |$\approx 14$|⁠ , highlighting it as a candidate multimessenger EMRI target. We also highlight the role of current and near-future X-ray and UV observatories in enabling multimessenger observations of EMRIs in conjunction with LISA, and conclude with a discussion of caveats of the current analysis, such as the exclusion of eccentricity and inclination from the model, and the measurability of subsolar mass compact object EMRIs. [ABSTRACT FROM AUTHOR]

We present the overview and first results from the North-PHASE Legacy Survey, which follows six young clusters for five years, using the 2 deg |$^2$| FoV of the JAST80 telescope from the Javalambre Observatory (Spain). North-PHASE investigates stellar variability on time-scales from days to years for thousands of young stars distributed over entire clusters. This allows us to find new YSO, characterize accretion, and study inner disc evolution within the cluster context. Each region (Tr 37, Cep OB3, IC 5070, IC 348, NGC 2264, and NGC 1333) is observed in six filters (SDSS griz, u band, and J0660, which covers H |$\alpha$|⁠), detecting cluster members as well as field variable stars. Tr 37 is used to prove feasibility and optimize the variability analysis techniques. In Tr 37, variability reveals 50 new YSO, most of them proper motion outliers. North-PHASE independently confirms the youth of astrometric members, efficiently distinguishes accreting and non-accreting stars, reveals the extent of the cluster populations along Tr37/IC 1396 bright rims, and detects variability resulting from rotation, dips, and irregular bursts. The proper motion outliers unveil a more complex star formation history than inferred from Gaia alone, and variability highlights previously hidden proper motion deviations in the surrounding clouds. We also find that non-YSO variables identified by North-PHASE cover a different variability parameter space and include long-period variables, eclipsing binaries, RR Lyr, and |$\delta$| Scuti stars. These early results also emphasize the power of variability to complete the picture of star formation where it is missed by astrometry. [ABSTRACT FROM AUTHOR]

We have investigated the behaviour of three strong near-infrared diffuse interstellar bands (DIBs) at λ13177 Å, λ14680 Å, and λ15272 Å, on a larger sample of sightlines and over a wider range of extinctions than previously studied, utilizing spectra from three observatories. We applied two telluric correction techniques to reduce atmospheric contamination and have used Gaussian fits to characterize the DIB profiles and measure equivalent widths. We confirmed strong and approximately linear correlations with reddening of the λ13177 Å, λ14680 Å, and λ15272 Å DIBs, extending them to higher reddening values and strengthening their link to interstellar matter. Modelling of the λ14680 Å DIB profiles revealed intrinsic variations, including line broadening, linked to their formation processes. This effect is particularly pronounced in the Galactic Centre (GC) environment, where multiple diffuse molecular clouds along the line of sight contribute to line broadening. We have detected one new DIB candidate at λ14795 Å on sightlines with high reddening. [ABSTRACT FROM AUTHOR]

This paper is an analysis of data from multicolor photometric observations of the asynchronous polar IGR J19552+0044 obtained over 59 nights from 2019-2022 at the Crimean Astrophysical Observatory, as well as at the Terskol Peak, Sanglokh, and Lesniki Observatories, and data from the TESS space telescope obtained on 27 days in 2022. It is shown that the maximum amplitude of the brightness oscillations at the rotation period of the white dwarf (~2m.5-3m) is observed in the Ic band and is essentially close to zero in the B band. The rotation period of the white dwarf is refined to 0.05645350(14) days. A dependence of the amplitude of the brightness curve of the rotation period on the phase of the synodic period is detected. [ABSTRACT FROM AUTHOR]

In 1905, a National Observatory for Canada was constructed to house a 15-inch equatorial telescope and other instruments in its complex. A Warner & Swasey telescope with a John A. Brashear lens was purchased and used for the study of the Moon, spectroscopic binary stars, and other pursuits. Curiously, the Brashear objective was unceremoniously replaced in 1958 with the world's largest apochromat. But there was no announcement in the Journals or even mention in the Observatory Annual Reports. Why replace the Brashear? And why no announcement? Was the Brashear defective? Was it assembled backwards? Was there something to hide? The personal papers and daily journals of the principal actors are examined to uncover the truth. [ABSTRACT FROM AUTHOR]

The Yarkovsky effect is one of the noticeable factors in the orbital evolution of near-Earth asteroids (NEAs). The A2 non-gravitational parameter describes the corresponding acceleration in the NEA motion model. This parameter can be derived from astrometric observations of the NEA. We present the results of astrometric observations of two NEAs (2010 XC15 and 2014 HK129). The measurements were performed with the MTM-500M telescope (Mountain Astronomical Station of the Pulkovo Observatory). The modified Gaia star apparent approach technique was applied. As a result, the astrometric accuracy of our observations reached the 0.05 arcsec level. It allowed us to estimate the A2 values of the 2010 XC15 asteroid: –139.5 × 10–15 ± 20.2 × 10–15 au/d2. It is in good agreement with the NASA JPL estimate for this asteroid. The 2014 HK129 A2 parameter formal value extracted from our data is 61.3 × 10–15 ± 1583.4 × 10–15 au/d2. Introduction of this A2 value into the asteroid motion model provides a significant decrease (about 0.05–0.1 arcsec) of the (O–C) values for the first epoch of 2014 HK129 observations. It can be considered as faint evidence of the reality of Yarkovsky drift for the 2014 HK129 asteroid. [ABSTRACT FROM AUTHOR]

Optical observations of the occultation of the star TYC 5254-00839-1 by Neptune's satellite Triton were carried out on October 6, 2022, using the Zeiss-1000 telescope at the Sanglokh Observatory (MPC code 193). As a result of photometric processing of images, a light curve of the star was constructed and it was revealed that the areas of decline and rise in brightness had a finite duration from 15 to 24 s. This is apparently due to the presence of an atmosphere around Triton. In addition, in the resulting light curve of this phenomenon, according to our and other observations, a "step" is revealed, which may indicate the possible presence of a close, faint object near the occulted star. As a result of astrometric processing, high-precision coordinates of Triton were determined at the average moment of occultation, which, within the limits of measurement errors, coincided with its ephemeris position. [ABSTRACT FROM AUTHOR]

Hydrograph separation procedures aim to separate the baseflow and quickflow components of streamflow. Although widely used, these procedures are considered arbitrary, as they are mostly based on sheer geometrical or mathematical concepts and involve only streamflow data. Because the in-stream chemical concentrations are known to be valuable indicators of the actual flow-generating processes, we propose here a calibration approach for one of the most common hydrograph separation methods: the Recursive Digital Filter (RDF). The proposed approach uses continuous in-stream chloride concentrations, measured at the ORACLE-Orgeval Observatory (France). For this, we combine the RDF method with the chloride solute through the mass balance method (MB) and a multi-objective optimization function. Results show that the calibration approach allows a better estimation of the chemical concentration time series tested at flood event and inter-annual scale. [ABSTRACT FROM AUTHOR]

We observed the low-mass X-ray binary Cyg X-2 for a total of 18 nights over two observing runs in July and September of 2006, using the Otto Struve Telescope at McDonald Observatory and the Rossi X-ray Timing Explorer. Using discrete cross-correlations, we found peaks occurring at near-zero lags in the flaring branch of the colour–colour diagram, which could signify reprocessing, in addition to an anticorrelation within the normal branch. When comparing optical flux to the system's placement on the Z track, two distinct behaviours were seen: (1) a state with no correlation, and (2) a multivalued (horizontal and normal branches)/correlated (flaring branch) state. The correlation was the result of direct steps and more gradual falls to and from the flaring branch, respectively. Finally, we modelled timed spectra with 64 s bins with an extended accretion disc corona model. We found that correlations occurred between the optical and the various fitted parameters, particularly the blackbody normalization (and blackbody radius by extension) in higher intensity regions. Despite this, the Z track location was found to be a far better predictor of physical parameters than the optical flux, with clean correlations seen in every branch of the Z track. Where optical correlations are found, the location on the Z track was a better predictor of optical flux than any individual physical parameter. [ABSTRACT FROM AUTHOR]

Context. Large sky surveys provide numerous non-targeted observations of small bodies of the Solar System. The upcoming LSST of the Vera C. Rubin Observatory will be the largest source of small body photometry in the next decade. With non-coordinated epochs of observation, colors – and therefore taxonomy and composition – can only be computed by comparing absolute magnitudes obtained in each filter by solving the phase function (evolution of brightness of the small body against the solar phase angle). Current models in use in the community (HG, HG12*, and HG1G2), however, fail to reproduce the long-term photometry of many targets due to the change in the aspect angle between apparitions. Aims. We aim to derive a generic yet simple phase function model accounting for the variable geometry of the small bodies over multiple apparitions. Methods. As a spinoff of the HG1 G2 model, we propose the sHG1G2 phase function model in which we introduce a term describing the brightness changes due to spin orientation and polar oblateness. We applied this new model to 13 245 908 observations of 122 675 Solar System objects (SSOs). These observations were acquired in the g and r filters with the Zwicky Transient Facility between November 1, 2019 and December 1, 2023. We retrieved them and implemented the new sHG1G2 model in FINK, a broker of alerts designed for the LSST. Results. The sHG1G2 model leads to smaller residuals than other phase function models, providing a better description of the photometry of asteroids. We determined the absolute magnitude, H, and phase function coefficients (G1, G2) in each filter, the spin orientation (α0, δ0), and the polar-to-equatorial oblateness, R, for 95 593 SSOs, which constitutes about a tenfold increase in the number of characterized objects compared to the current census. Conclusions. The application of the sHG1 G2 model to ZTF alert data using the FINK broker shows that the model is appropriate for extracting physical properties of asteroids from multi-band and sparse photometry, such as the forthcoming LSST survey. [ABSTRACT FROM AUTHOR]

Context. Dual-field interferometric observations with VLTI/GRAVITY sometimes require the use of a binary calibrator. This is a binary star whose individual components remain unresolved by the interferometer, with a separation between 400 and 2000 mas for observations with the Unit Telescopes (UTs), or 1200–3000 mas for the Auxiliary Telescopes (ATs). The separation vector also needs to be predictable to within 10 mas for a proper pointing of the instrument. Aims. No list of properly vetted calibrators was available so far for dual-field observations with VLTI/GRAVITY on the UTs. Our objective is to compile such a list and make it available to the community. Methods. We identified a list of candidates from the Washington Double Star (WDS) catalogue, all with appropriate separations and brightness, scattered over the southern sky. We observed them as part of a dedicated calibration programme, determined whether these objects were true binaries (excluding higher multiplicities resolved interferometrically, but unseen by imaging), and extracted measurements of the separation vectors. We combined these new measurements with those available in the WDS to determine updated orbital parameters for all our vetted calibrators. Results. We compiled a list of 13 vetted binary calibrators for observations with VLTI/GRAVITY on the UTs, and we provide orbital estimates and astrometric predictions for each of them. We show that our list guarantees that there are always two binary calibrators at least at an airmass < 2 in the sky over the Paranal observatory at any point in time. Conclusions. Any principal investigator wishing to use the dual-field mode of VLTI/GRAVITY with the UTs can now refer to this list to select an appropriate calibrator. We encourage the use of whereistheplanet to predict the astrometry of these calibrators, which seamlessly integrates with p2Gravity for VLTI/GRAVITY dual-field observing material preparation. [ABSTRACT FROM AUTHOR]

Autotrophic microaerophilic iron-oxidizing Zetaproteobacteria seem to play an important role in mineral weathering and metal corrosion in different environments. Here, we compare the bacterial and zetaproteobacterial communities of a mature iron-rich mat together with in situ incubations of different Fe-bearing materials at the EMSO-Ligure West seafloor observatory, which is located on the abyssal plain in the NW Mediterranean Sea. Our results on bacterial communities enable us to make a clear distinction between those growing on mild steel anthropic substrata and those developing on basaltic substrata. Moreover, on anthropic substrata we highlight an influence of mat age on the bacterial communities. Regarding zetaproteobacterial communities, our results point to an increase in ZetaOTUs abundance and diversification with the age of the mat. We corroborate the key role of the ZetaOTU 2 in mat construction, whatever the environment, the substrata on which they develop or the age of the mat. We also show that ZetaOTU 28 is specific to anthropogenic substrata. Finally, we demonstrate the advantage of using dPCR to precisely quantify very low abundant targets, as Zetaproteobacteria on our colonizers. Our study, also, allows to enrich our knowledge on the biogeography of Zetaproteobacteria, by adding new information on this class and their role in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

The ecology of forest ecosystems depends on the composition of trees. Capturing fine-grained information on individual trees at broad scales provides a unique perspective on forest ecosystems, forest restoration, and responses to disturbance. Individual tree data at wide extents promises to increase the scale of forest analysis, biogeographic research, and ecosystem monitoring without losing details on individual species composition and abundance. Computer vision using deep neural networks can convert raw sensor data into predictions of individual canopy tree species through labeled data collected by field researchers. Using over 40,000 individual tree stems as training data, we create landscape-level species predictions for over 100 million individual trees across 24 sites in the National Ecological Observatory Network (NEON). Using hierarchical multi-temporal models fine-tuned for each geographic area, we produce open-source data available as 1 km2 shapefiles with individual tree species prediction, as well as crown location, crown area, and height of 81 canopy tree species. Site-specific models had an average performance of 79% accuracy covering an average of 6 species per site, ranging from 3 to 15 species per site. All predictions are openly archived and have been uploaded to Google Earth Engine to benefit the ecology community and overlay with other remote sensing assets. We outline the potential utility and limitations of these data in ecology and computer vision research, as well as strategies for improving predictions using targeted data sampling. Detailed maps of tree species can be used for forest analysis, biogeographic research and ecosystem monitoring. This study provides individual tree species maps for 24 sites in the United States National Ecological Observatory Network (NEON), covering 80 tree species and 100 million individuals. [ABSTRACT FROM AUTHOR]

This paper presents a deep-learning-based method to detect recreational vessels. The method takes advantage of existing underwater acoustic measurements from an Estuarine Soundscape Observatory Network based in the estuaries of South Carolina (SC), USA. The detection method is a two-step searching method, called Deep Scanning (DS), which includes a time-domain energy analysis and a frequency-domain spectrum analysis. In the time domain, acoustic signals with higher energy, measured by sound pressure level (SPL), are labeled for the potential existence of moving vessels. In the frequency domain, the labeled acoustic signals are examined against a predefined training dataset using a neural network. This research builds training data using diverse vessel sound features obtained from real measurements, with a duration between 5.0 seconds and 7.5 seconds and a frequency between 800 Hz to 10,000 Hz. The proposed method was then evaluated using all acoustic data in the years 2017, 2018, and 2021, respectively; a total of approximately 171,262 2-minute.wav files at three deployed locations in May River, SC. The DS detections were compared to human-observed detections for each audio file and results showed the method was able to classify the existence of vessels, with an average accuracy of around 99.0%. [ABSTRACT FROM AUTHOR]

The New Advanced Telescope for High ENergy Astrophysics (NewAthena) will be the largest space‐based X‐ray observatory ever built. It will have an effective area above 1.1 m2 at 1 keV, which corresponds to a polished mirror surface of about 300 m2 due to the grazing incidence. As such a mirror area is not achievable with an acceptable mass even with nested shells, silicon pore optics (SPO) technology will be utilized. In the PTB laboratory at BESSY II, two dedicated beamlines are in use for their characterization with monochromatic radiation at 1 keV and a low divergence well below 2 arcsec: the X‐ray Pencil Beam Facility (XPBF 1) and the X‐ray Parallel Beam Facility (XPBF 2.0), where beam sizes up to 8 mm × 8 mm are available while maintaining low beam divergence. This beamline is used for characterizing mirror stacks and controlling the focusing properties of mirror modules (MMs) – consisting of four mirror stacks – during their assembly at the beamline. A movable CCD based camera system 12 m from the MM registers the direct and the reflected beams. The positioning of the detector is verified by a laser tracker. The energy‐dependent reflectance in double reflection through the pores of an MM with an Ir coating was measured at the PTB four‐crystal monochromator beamline in the photon energy range 1.75 keV to 10 keV, revealing the effects of the Ir M edges. The measured reflectance properties are in agreement with the design values to achieve the envisaged effective area. [ABSTRACT FROM AUTHOR]

Land use changes and reforestation impact soil phosphorus (P) distribution over extended periods. This study examines P distribution in forest development from 1957 to 2017 at the Calhoun Critical Zone Observatory in South Carolina. Tracking changes in 0–60 cm mineral soil P fractions through six samplings in eight continuously uncut plots and eight plots cut in 2007 (replanted in 2009), we hypothesized an increase in soil organic P (Po) over time in uncut plots, at the expense of HCl‐extractable P (i.e., Ca‐P). This hypothesis is based on the expectation of a transfer of P from easily accessible forms, possibly from historic fertilization to organic reservoirs within the soil. Meanwhile, we expect to lose Po in cut plots due to disturbance and residue decomposition, and increase bioavailable Mehlich‐III extractable P (Mehlich‐III P), resin inorganic phosphorus (Pi), and HCO3 Pi. Results revealed a continued decrease in Mehlich‐III P in uncut (38.7–15.7 µg g−1) and cut plots (25.2–17.7 µg g−1) within the 0–7.5 cm range. NaOH‐Po in uncut plots remained stable, while in cut plots, it increased by ∼4 µg g−1 in the 0–7.5 cm soil layer. Slowly cycling Po (NaOH‐Po) increased during forest regrowth in the cut plots, aligning with rising soil organic carbon and decreasing soil pH. Soil P changes indicate minor declines in available fractions during the initial three decades, with the HCl extractable (Ca‐P) fraction experiencing the highest depletion. In the later three decades, P associated with NaOH extraction (i.e., iron [Fe] and aluminum [Al] bound P) declined, although estimated mineral soil P removals during this period were less than accumulated P in tree biomass and forest floor. The total soil P decline from 1990 to 2017 was 34 kg ha−1, suggesting a growing role of P recycling from debris decomposition in supplying soil P to plants. Core Ideas: Phosphorus distribution in mineral soils is dynamic across a forest's developmental timeline from 1957 to 2017.Phosphorus recycling from forest floor and soil organic P contributes to plant nutrient supply.An agricultural fertilization legacy is still influencing long‐term phosphorus cycling.The decadal timescale of this study highlights the role of slowly cycling phosphorus fractions over extended time scales. [ABSTRACT FROM AUTHOR]

Accurate ensembles of precipitation data play an important role in precise and efficient drought monitoring systems at the regional level. This article proposes a weighted aggregation scheme – the Divergence and Interdependence-based Hybrid Weighting Scheme (DIHWS) – to ensemble precipitation data for accurate regional drought analysis. The derivation of weights is based on the interdependence among meteorological observatories and the divergence from the mean characteristics of regional data. Here, the interdependence among meteorological observatories is assessed using the Bayesian Network theory. At the same time, the divergence from the mean characteristics of regional data is based on the set of equations used for regional aggregation in (Ali et al., Water Resour Manage 36:4099–4114, 2022). Consequently, the paper introduces a new regional drought index – the Bayesian Network-based Adaptive Regional Drought Index (BNARDI). BNARDI is a standardized regional index and used estimated at multiple time scales. The application of DIHWS and BNARDI is based on five regions of varying observatories. We observed smaller MAE values associated with DIHWS than its Simple Model Average (SMA) and one other of its relevant compitator in all the regions. Therefore, we conclude that the proposed weighting scheme and drought index are more reliable for regional drought monitoring and forecasting. Additionally, the research includes various forecasting models to assess their appropriateness for forecasting the new regional index. The results of this research demonstrate that no single method is suitable for forecasting complex drought data, as generated by BNARDI. Therefore, we suggest using varying methods or a hybrid of various candidate forecasting models for forecasting BNARDI. [ABSTRACT FROM AUTHOR]

The article seeks to show that every means of payment admitted as money entails both the materialization of a commitment assumed by its issuer and potential benefits resulting from the provision of admissible transactional instruments. Consequently, the material and institutional changes experienced in the long term by the means of payment have implied modifications in the ways of formulating those commitments and in the way of negotiating the distribution of the reported benefits. The case of the Río de la Plata, an economy lacking in local metalliferous production, offers an observatory to understand how different governments materialized their commitments in means of payment and distributed the benefits resulting from their provision, demonstrating the changes experienced between the Hispanic and post-revolutionary periods to focus, then, on the change that opened the door to a period whose matrix has been sustained ever since: the irruption of the banking system and its payment instruments. [ABSTRACT FROM AUTHOR]

The Simons Observatory (SO) is a cosmic microwave background instrumentation suite in the Atacama Desert of Chile. More than 65,000 polarization-sensitive transition-edge sensor (TES) bolometers will be fielded in the frequency range spanning 27 to 280 GHz, with three separate dichroic designs. The mid-frequency 90/150 GHz and ultra-high-frequency 220/280 GHz detector arrays, fabricated at NIST, account for 39 of 49 total detector modules and implement the feedhorn-fed orthomode transducer-coupled TES bolometer architecture. A robust production-level fabrication framework for these detector arrays and the monolithic DC/RF routing wafers has been developed, which includes single device prototyping, process monitoring techniques, in-process metrology, and cryogenic measurements of critical film properties. Application of this framework has resulted in timely delivery of nearly 100 total superconducting focal plane components to SO with 88 % of detector wafers meeting nominal criteria for integration into a detector module: a channel yield > 95 % and T c in the targeted range. [ABSTRACT FROM AUTHOR]

The Simons Observatory is a cosmic microwave background experiment stationed atop Cerro Toco, at an elevation of 5200 ms in Chile's Atacama Desert. The receivers of the Observatory will contain more than 60,000 transition edge sensor bolometers. In order to read out this large detector count in a scalable manner, we utilize a microwave superconducting quantum interference device (SQUID) multiplexing scheme where each detector is inductively coupled to an rf SQUID, which in turn is inductively coupled to a GHz resonator. More than 2000 SQUIDs and resonators are fabricated on a single 76.2-mm-diameter silicon wafer. To qualify wafers before integration, we cryogenically screen ∼ 10% of the devices on each wafer by use of a standard set of measurements. From these data, we report parameter value trends in 47 wafers that were fabricated in the past two years. We show good control in key parameters such as frequency placement, internal quality factor, and response to applied flux. We demonstrate a wafer acceptance yield of 86%. [ABSTRACT FROM AUTHOR]

A large and ever-growing body of geophysical information is measured in campaigns and at specialized observatories as a part of scientific expeditions and experiments. These collections of observed data include many essential climate variables (as defined by the Global Climate Observing System) but are often distinguished by a wide range of additional non-routine measurements that are designed to not only document the state of the environment but also the drivers that contribute to that state. These field data are used not only to further understand environmental processes through observation-based studies but also to provide baseline data to test model performance and to codify understanding to improve predictive capabilities. To address the considerable barriers and difficulty in utilizing these diverse and complex data for observation–model research, the Merged Observatory Data File (MODF) concept has been developed. A MODF combines measurements from multiple instruments into a single file that complies with well-established data format and metadata practices and has been designed to parallel the development of corresponding Merged Model Data Files (MMDFs). Using the MODF and MMDF protocols will facilitate the evolution of model intercomparison projects into model intercomparison and improvement projects by putting observation and model data "on the same page" in a timely manner. The MODF concept was developed especially for weather forecast model studies in the Arctic. The surprisingly complex process of implementing MODFs in that context refined the concept itself. Thus, this article explains the concept of MODFs by providing details on the issues that were revealed and resolved during that first specific implementation. Detailed instructions are provided on how to make MODFs, and this article can be considered a MODF creation manual. [ABSTRACT FROM AUTHOR]

This paper presents the state-of-the-art techniques employed in aerothermal modeling to respond to the current observatory design challenges, particularly those of the next generation of extremely large telescopes (ELTs), such as the European ELT, the Thirty Meter Telescope International Observatory (TIO), and the Giant Magellan Telescope (GMT). It reviews the various aerothermal simulation techniques, the synergy between modeling outputs and observatory integrating modeling, and recent applications. The suite of aerothermal modeling presented includes thermal network models, Computational Fluid Dynamics (CFD) models, solid thermal and deformation models, and conjugate heat transfer models (concurrent fluid/solid simulations). The aerothermal suite is part of the overall observatory integrated modeling (IM) framework, which also includes optics, dynamics, and controls. The outputs of the IM framework, nominally image quality (IQ) metrics for a specific telescope state, are fed into a stochastic framework in the form of a multidimensional array that covers the range of influencing operational parameters, thus providing a statistical representation of observatory performance. The applications of the framework range from site selection, ground layer characterization, and site development to observatory performance current best estimate and optimization, active thermal control design, structural analysis, and an assortment of cost–performance trade studies. Finally, this paper addresses planned improvements, the development of new ideas, attacking new challenges, and how it all ties to the "Computational Fluid Dynamics Vision 2030" initiative. [ABSTRACT FROM AUTHOR]

Purpose: The article aims to identify the relationships between artificial intelligence and digital labour platforms and how these relationships are potentially significant for human labour in the light of the labour reinstatement effect. Design/methodology/approach: The theoretical part drew on the reinstatement effect hypothesis, while the empirical part used Online Labour Observatory data. The analysis concerned the changes that occurred in the

Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world's population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world's population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion. [ABSTRACT FROM AUTHOR]

Polar stratospheric clouds (PSCs) form in polar regions, typically between 15 and 25 km above mean sea level, when the local temperature is sufficiently low. PSCs play an important role in the ozone chemistry and the dehydration and denitrification of the stratosphere. Lidars with a depolarization channel may be used to detect and classify different classes of PSCs. The main PSC classes are water ice, nitric acid trihydrate (NAT), and supercooled ternary solutions (STSs), the latter being liquid droplets consisting of water, nitric acid, and sulfuric acid. PSCs have been observed at the lidar observatory at Concordia Station from 2014 onward. The harsh environmental conditions at Concordia during winter render successful lidar operation difficult. To facilitate the operation of the observatory, several measures have been put in place to achieve an almost complete remote control of the system. PSC occurrence is strongly correlated with local temperatures and is affected by dynamics, as the PSC coverage during the observation season shows. PSC observations in 2021 are shown as an example of the capability and functionality of the lidar observatory. A comparison of the observations with the satellite-borne CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar has been made to demonstrate the quality of the data and their representativeness for the Antarctic Plateau. [ABSTRACT FROM AUTHOR]

Atmospheric turbulence characteristics are essential in determining the quality of astronomical images and implementing adaptive optics systems. In this study, the vertical distributions of optical turbulence at the Peak Terskol observatory (43.27472°N 42.50083°E, 3127 m a.s.l.) using the Era-5 reanalysis and scintillation measurements are investigated. For the closest reanalysis grid node to the observatory, vertical profiles of the structural constant of the air refractive index turbulent fluctuations C n 2 were obtained. The calculated C n 2 (z) vertical profiles are compared with the vertical distribution of turbulence intensity obtained from tomographic measurements with a Shack–Hartmann sensor. The atmospheric coherence length at the location of Terskol Peak was estimated. Using a combination of atmospheric models and paramaterization schemes of turbulence, C n 2 (z) profiles at Mt. Kurapdag were obtained. The values of atmospheric coherence length at Peak Terskol are compared with estimated values of this length at the ten astronomical sites, including Ali, Lenghu and Daocheng. [ABSTRACT FROM AUTHOR]

The three spacecraft of the space gravitational wave antenna employ heterodyne interferometry to mitigate the effects of Doppler shift. Constrained by laser relative intensity noise (RIN) and the sampling frequency constraints of phase readout circuits, the widespread adoption of fixed offset frequencies effectively regulates the frequency of heterodyne interferometric beat notes within a reasonable frequency domain of [5 MHz, 25 MHz]. In this work, a high-precision fitness genetic algorithm for heterodyne interferometry is utilized to generate the initial offset frequency distribution scheme. To address issues with unreasonable switching times and offset frequency settings in the initial scheme for partial frequency domains, optimization strategies are proposed from three aspects: frequency domain selection extension, switch times control, and numerical low frequency. Results demonstrate that the optimization of frequency domain selection extension narrows the reasonable frequency domain to [5 MHz, 15 MHz] and [7 MHz, 17 MHz]. Optimization of switch times control ensures that switching times of offset frequency distribution scheme generated under the settings of [6 MHz, 17 MHz] and wider frequency domains can be controlled within a reasonable range of 6 to 13 times. Fixed offset frequency settings are generally reduced by 24.3% after low-frequency optimization. This methodology and result can provide a reliable reference for Program Taiji and even related space gravitational wave antenna projects. [ABSTRACT FROM AUTHOR]

Introduction: Agricultural drainage ditches are essential for maintaining flow efficiency and are often managed by brushing (i.e., vegetation clearing along ditch banks) and dredging. These maintenance practices not only impact flow but also the ditches' capacity to process and assimilate agricultural chemicals. However, the influence of ditch management on microbial activities, essential in processing and transforming these contaminants, remains underexplored. Methods: We conducted a four-year surface water sampling campaign in two long-established (over 40 years) agricultural drainage ditches situated in eastern Ontario, Canada. One drainage ditch underwent intensive bank brushing and channel dredging, while the other remained unmanaged. We assessed the impact of these contrasting ditch management practices on the diversity and compositional structure of surface water microbiome communities, with a particular focus on the distribution of genes associated with nitrogen (N) cycling, using shotgun metagenomics sequencing and an assembly-based metagenome approach. Results and discussion: From 117 surface water samples, we reconstructed 157 metagenome-assembled genomes (MAGs), predominantly from the Patescibacteria superphylum. Brushing alone, conducted about 10 months prior to dredging, had an insignificant impact on the aquatic microbial community. However, dredging led to a significant reduction in community diversity and abundance of genes affiliated with denitrification, dissimilatory nitrate reduction to ammonia, and complete nitrification through comammox. Ditch management resulted in noticeable shifts in the microbial community, evidenced by the enrichment of taxa in Polaromonas, Emticicia, Flectobacillus, and Patescibacteria in the water of the managed ditch sites. The metagenomes of these taxa harbor genes involved in various nitrogen biotransformation pathways. Interestingly, following dredging, the levels of ammonia and ammonium, nitrite, and total Kjeldahl N in the managed ditch did not increase, but significantly decreased; likely due to ditch substrate removal and potentially increased flow efficiency and dilution. Being one of the few studies conducted to date, this study provided unique insights into the consequences of drainage ditch management on freshwater microbiomes involved in N cycling. [ABSTRACT FROM AUTHOR]