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The Type Ia supernova 2021hem: A 2003fg-like event in an apparently hostless environment
No full textWe report observations of a Type Ia supernova (SN Ia) 2021hem that was discovered within 48 hours of last nondetection and is located in an apparently hostless environment. With a peak absolute B-band magnitude of MB, max = −19.96 ± 0.29 mag, SN 2021hem lies at the luminous end of the SNe Ia distribution. Its near-infrared and i-band light curves lack the secondary maximum, which is otherwise ubiquitous to normal and 1991T-like SNe Ia. Instead, these properties cause SN 2021hem to closely resemble 2003fg-like events. The slowly evolving light curves (characterized by Δm15(B) = 1.02 ± 0.02 mag; sBV = 0.94 ± 0.05) and the earliest spectrum showing C I
The AIDA-TNG project: 3D halo shapes
No full textContext. The shapes of dark matter halos can be used to constrain the fundamental properties of dark matter. In standard cold dark matter (CDM) cosmologies, halos are typically triaxial, with a preference for prolate configurations; however, including the full baryonic physics tends to make them more oblate.
Aims. We focus on the characterization of total matter 3D shapes in alternative dark matter models, such as self-interacting dark matter (SIDM) and warm dark matter (WDM). These scenarios predict different structural properties due to collisional effects or the suppression of small-scale power.
Methods. We measured the different halo component shapes – dark matter, stars, and gas – at various radii from the center in AIDA-TNG (Alternative Interacting Dark Matter and Astrophysics – TNG), which is a suite of high-resolution cosmological simulations built upon the IllustrisTNG framework. The intent was to systematically study how different dark matter models – specifically SIDM and WDM – affect galaxy formation and the structure of dark matter halos when realistic baryonic physics is included.
Results. SIDM models tend to produce rounder and more isotropic halos, especially in the inner regions, as a result of momentum exchange between dark matter particles. Group- and cluster-size WDM halos are also slightly more spherical than their CDM counterparts. In all cases, the inclusion of self-consistent baryonic physics makes the central regions of all halos rounder, while still revealing clear distinctions among the various dark matter models, notably the self-interacting ones.
Conclusions. The general framework presented in this work, based on the 3D halo shape, can be useful for interpreting multiwavelength data analyses of galaxies and clusters
Evaluation of urban flood resilience and analysis of obstacle factors in northeast Sichuan based on PSR modeling
No full textIn this study, a comprehensive evaluation system of flood resilience is constructed based on the PSR framework with five cities in the northeastern region of Sichuan Province as samples. By quantitatively assessing the development dynamics of urban flood resilience during the decade 2014-2023, and applying the barrier degree model to identify key constraints. It is found that: the overall level of urban flood resilience in the study area shows a steady improvement trend, but the spatial differentiation characteristics are significant, and there are obvious gaps in the level of resilience development among different cities; river density, topographic slope and over-density of population are the main constraints to the regional resilience enhancement of the obstacle factors. Based on this, it is recommended to adopt differentiated management strategies, strengthen the layout of flood control infrastructure in areas with significant topographic relief, optimize the spatial distribution pattern of population to reduce disaster exposure, and systematically promote the ecological restoration of urban water systems and comprehensive management projects, so as to enhance the resilience level of regional floods with a multi-dimensional synergistic path
Performance-Oriented Assessment of 3D-Printed Architecture for Small-Scale Housing
No full text3D-printed architecture is becoming a viable alternative to conventional masonry and cast-in-place construction, especially for rapid, low-cost, and low-waste buildings. To clarify its actual performance, this study develops an integrated cost–time–waste evaluation model and applies it to a 50 m² single-story 3D-printed concrete house. A comparable conventional house is used as a baseline. The results show that the printed scheme shortens structural-shell construction from 18–20 days to about 2 days, reduces total project duration by about 80%, lowers direct construction cost by 22%, and cuts construction waste by about 78%. A structural capacity margin analysis further indicates that, when vertical voids are post-grouted and a reinforced ring beam is added, the printed walls can achieve the target compressive strength of 30 MPa with an observed mean of 32 MPa. The proposed Integrated Performance Index (IPI), combining time, cost, and waste with adjustable weights, provides a quantitative tool to compare printed and non-printed solutions. The study concludes that 3D-printed architecture is technically feasible and performance-efficient for single-story housing, but its benefits depend on process control, printer utilization, and reinforcement integration
Research on biological detection technology based on fluorescence principles
No full textBiological detection technology plays an important role in the fields of disease diagnosis, environmental monitoring and food safety. Among them, detection technology based on optical principle has the advantages of high sensitivity, fast response and non-destructive, which has led to its rapid development. In this review, we systematically review the principles, progress and applications of fluorescence detection, which achieves ultrasensitive detection and dynamic monitoring of biomolecules through the strategies of fluorescence labeling, fluorescence lifetime imaging, fluorescence polarization immunoassay and fluorescence resonance energy transfer. In the future, the combination of multiple technologies, intelligent data analysis, and portable device development will become important directions for the development of optical detection technology, further promoting its application in precision medicine and environmental monitoring
Energy release and Griffith’s criterion for phase-field fracture
No full textPhase-field evolutions are obtained by means of time discrete schemes, providing (or selecting) at each time step an equilibrium configuration of the system, which is usually computed by descent methods for the free energy (e.g. staggered and monolithic schemes) under a suitable irreversibility constraint on the phase-field parameter. We consider a class of phase-field energies including both volumetric-deviatoric and spectral decomposition; we study in detail the time continuous limits of these evolutions considering monotonicity as irreversibility constraint and providing a general result, which holds independently of the scheme employed in the incremental problem. In particular, we show that in the steady state regime the limit evolution is simultaneous (in displacement and phase field parameter) and satisfies Griffith’s criterion in terms of toughness and phase field energy release rate. In the unsteady regime the limit evolution may instead depend on the adopted scheme and Griffith’s criterion may not hold. We prove also the thermodynamical consistency of the monotonicity constraint over the whole evolution, and we study the system of PDEs (actually, a weak variational inequality) in the steady state regime. Technically, the proof employs a suitable reparametrization of the time discrete points, whose Kuratowski limit characterizes the set of steady state propagation. The study of the quasi-static time continuous limit relies on the strong convergence of the phase-field function together with the convergence of the power identity
Comparison of historic and novel data reveals higher contemporary diversity of trematode metacercariae in freshwater fish
No full textTrematode metacercariae are the most abundant and frequently encountered helminths in freshwater fish. Yet, accurate species identification remains challenging, potentially leading to an underestimation of trematode diversity. Using data from parasitological examinations of 1,030 fish (47 species) collected from diverse freshwater habitats in Lithuania (2022–2024), we assessed the contemporary diversity of trematode metacercariae, host associations, microhabitat preferences, and changes in diversity patterns and transmission dynamics. Through integrated morphological and molecular techniques, we identified metacercariae belonging to 51 species from eight families, more than doubling previously reported diversity (25 species). While trematode family composition remained largely unchanged – the Diplostomidae and Strigeidae remained the most diverse families – notable differences were observed at the species level. Metacercariae of the Echinochasmidae and Echinostomatidae were detected for the first time, while previously reported Clinostomidae were absent. Fish of the Leuciscidae hosted the highest trematode diversity. Host specificity of metacercariae was generally low, with most species being euryxenous. At the microhabitat level, eyes harboured the highest number of species, while muscles showed the highest metacercarial density. Notably, we detected species first genetically characterised in North America (Echinoparyphium sp. 2 and Ichthyocotylurus sp. 2) and species potentially belonging to the genus Neogogatea, previously known only from Asia and North America, highlighting potential invasion risks and suggesting that European trematode diversity remains substantially underestimated. Future efforts should obtain molecular data from correctly identified adult specimens to resolve the identity of species currently identified only to the genus or family level, thereby enabling assessment of their geographical distributions and ecological roles
Multi-messenger observations of binary neutron star mergers: Synergies between next-generation gravitational wave interferometers and wide-field, high-multiplex spectroscopic facilities
No full textContext. Third-generation gravitational wave (GW) observatories, such as the Einstein Telescope (ET) and Cosmic Explorer (CE), will access a large volume of the Universe, and detect hundreds of thousands of binary neutron star (BNS) mergers, reaching distances beyond z ∼ 3. The unique information revealed by joint GW and electromagnetic (EM) detections can be fully exploited only with a dedicated observing strategy and suitably adapted EM facilities.
Aims. In this work, we explore the impact of integral field and multi-object spectroscopy (IFS and MOS) with the Wide-field Spectroscopic Telescope (WST) on the detection of EM counterparts from BNS detected by next-generation GW observatories.
Methods. We considered populations of BNS mergers assuming different equations of state and mass distributions. We computed the corresponding GW signals for both the ET operating alone and in a network with CE. Kilonova (KN) light curves were assigned using either AT2017gfo-like models or numerical-relativity-informed ones. Gamma-ray burst (GRB) afterglow emission was also included. We considered two main observing strategies: one in synergy with wide-field photometric surveys and a second based on a galaxy-targeted approach, exploiting WST’s high multiplexing capabilities. We also estimated the number of galaxies within the GW error volume. Here, we discuss potential observational challenges and corresponding mitigation strategies.
Results. We find that KNe from BNS mergers can be detected with WST up to z ∼ 0.4 and magnitudes mAB ∼ 25, while GRB afterglows may be observable at higher redshifts, z > 1, for viewing angles of Θview ≲ 15°. We show that Target of Opportunity (ToO) observations aimed at KN detections can be optimally scheduled 12–24 hours after the merger. For GRB afterglows, particularly in cases of a poor localisation in the first minutes after the high-energy detection, WST IFS can play a key role in counterpart identification and position refinement. Our results show that mini-IFUs (fibre bundles) and galaxy catalogues that are complete in redshift up to z ≤ 0.5 will be essential for the efficient identification of EM counterparts. We find that the WST contribution is also valuable for events with good sky localisation because the uncertainties in luminosity distance (even at low redshift) can result in large error volumes containing numerous galaxies to target up to several thousands at z < 0.1 and tens of thousands at z < 0.2 for GW detections of ET in a network with CE. Finally, we underline that events at redshifts of z < 0.3 and with sky localisations better than 10deg2 will be ‘golden’ events for WST, making it become possible for WST to cover all the galaxies in the error volume with a limited number of exposures. We estimate these to range from about ten (ET-alone configuration) to hundreds per year (ET + CE configuration).
Conclusions. The detection and characterisation of EM counterparts of BNS mergers explored by next-generation interferometers will be challenging. Observational strategies and selection criteria should be defined in advance to prioritise events for follow-up among the potentially thousands per year expected from ET and CE. Detecting their EM counterparts will require facilities capable of covering sky regions of tens of deg2, reaching depths of AB > 22, and rapidly gathering the data needed to identify the many candidate sources expected for each event. We have shown that spectroscopic facilities with large fields of view, high sensitivity, and high-multiplexing modes are powerful instruments to successfully exploit the new multi-messenger science opportunities that will be opened up thanks to next-generation GW interferometers
Space Telescope proper motions of Large Magellanic Cloud star clusters
No full textIn this paper, we explore the kinematic properties of a sample of 19 young (<1 Gyr) and intermediate-age (1–2.5 Gyr) massive star clusters within the Large Magellanic Cloud (LMC). We analysed the proper motions of the clusters, which have been measured based on multi-epoch Hubble Space Telescope (HST) observations. Additionally, from the HST data we inferred homogeneous and robust estimates for the distances, ages, and metallicities of the clusters. This collection of information, in combination with literature line-of-sight velocities, allowed us to investigate the full 3D dynamics of our sample of clusters within the frame of the LMC in a self-consistent way. While most young clusters orbit the LMC close to the stellar disc plane, NGC 1850 (∼100 Myr old) depicts a peculiar case. Depending on the exact distance from the disc, it follows either a highly inclined retrograde orbit or an eccentric orbit along the bar structure. The orbits of young clusters that formed north of the LMC centre show signs that might be connected to the resettling motion of the LMC bar structure. Based on the dynamic properties in combination with the positions of the clusters in the age-metallicity space, we find no clear-cut evidence of clusters in our sample that could have been stripped from the Small Magellanic Cloud (SMC) onto the LMC. Finally, we compared the kinematics of the intermediate-age clusters with a suite of simple numerical simulations of the Magellanic system to interpret the cluster motions. A possible interaction history of the LMC with the SMC, where the SMC had two past crossings of the LMC disc plane (about 300 and 900 Myr ago), in combination with the recent SMC pericentre passage, can qualitatively explain the observed kinematic structure of the clusters analysed in this work
Development of green lanes on collector roads in Surakarta
No full textGreen lane is one of the green open space functioning to reduce pollution air in urban areas. The research aims to formulate directions development of green lanes on the collector roads in Surakarta. Method analysis used is descriptive quantitative, with utilize analysis spatial in the process of processing GIS data and translating results process data into informative. While quantitative analysis used technique scoring for determine development areas of green lanes. The process analysis carried out is traffic density analysis, comfort level analysis and density canopy analysis. This research shows that there is as many as 71 collectors roads section in Surakarta which classified the green lanes development in two classifications, specifically: Priority 1 (very need development) and Priority 2 (requires development). Analysis results show there are 4 sections of collector road which in priority 1 green lanes development, specifically Kapten Mulyadi Road, Komodor Yos Sudarso Road, S. Parman Road, and Sutan Syahrir Road