bluuebunny/crossref_metadata_2025 huggingface dataset:
The pathotome and precision health
Authors: Younes Kyan , Mormino Elizabeth C
Published: May 2023

This scientific commentary refers to ‘Pathological combinations in neurodegenerative disease are heterogeneous and disease-associated’ by Robinson et al. (https://doi.org/10.1093/brain/awad059).
Study on carnauba wax as phase-change material integrated in evacuated-tube collector for solar-thermal heat production
Authors: Bartali Ruben , Bolognese Michele , Fronza Nicola , Prattico Luca , Zanetti Alberto , Osorio Tiago , Crema Luigi
Published: May 2023

The evacuated-tube collector (ETC) for solar heat production is one of the most efficient systems to convert Sun energy into usable energy. Unfortunately, some technological barriers are still present in solar-thermal heat systems that limit the use of these technologies to decarbonize processes. An important obstacle is the requirement for heat at stable temperatures, which is not always achievable by solar fields, e.g. variable sky. For that reason, in this work, we studied the phase-change materials embedded in the ETC to keep stable the water temperature for a short period (minutes, hours). In this study, carnauba wax was used as a sustainable phase-change material (PCM), to avoid the use of PCM based on hydrocarbon waxes. The PCM has been packaged using a polyethylene bag inserted into an ETC with heat-pipe technologies and tested. The collector has been tested outdoors under solar irradiation and under shading conditions. The experimental results show that is possible to detect a sensible effect of the PCM on the temperature using 4 kg of carnauba wax while there is an important effect on the temperature stabilization using 9 kg of PCM. Using 9 kg of the PCM, we observed a stability of the outlet water temperature at 65°C for 30 minutes under shading conditions.
Screening for hepatic fibrosis in patients with psoriasis prescribed methotrexate: can we make a change?
Authors: Lyons Daniel , Callaghan Grainne , Murray Gregg , Ryan John , Roche Muireann
Published: May 2023

The aim of this study was to assess whether correlation existed between procollagen III N-terminal peptide levels, used for monitoring for hepatic fibrosis in patients with psoriasis prescribed methotrexate, and other screening tools (Fibrosis-4 score) and then resultant FibroScan®, with the aim of potentially altering current clinical practice. The retrospective analysis highlighted how both screening tools, if used, can prompt onward referral for FibroScan; however, the small sample size limited statistical conclusions. Nevertheless, we feel this observational study can help guide future investigation into potential changes to hepatic fibrosis monitoring for this cohort.
Gamified learning in dermatology and dermoscopy education: a paradigm shift
Authors: Donoso Francisca , Peirano Dominga , Longo Caterina , Apalla Zoe , Lallas Aimilios , Jaimes Natalia , Navarrete-Dechent Cristian
Published: May 2023

Teaching methods in medical education have been changing. More recent teaching modalities have gone beyond the traditional delivery of knowledge, promoting learning motivation, and improving teaching and learning outcomes. ‘Gamification’ and ‘serious games’ are methodologies that use the principles of games to facilitate learning processes and the acquisition of skills and knowledge, thereby improving attitudes towards learning when compared with traditional teaching methods. As dermatology is a visual field, images are a key component of different teaching strategies. Likewise, dermoscopy, a noninvasive diagnostic technique that allows the visualization of structures within the epidermis and upper dermis, also uses images and pattern recognition strategies. A series of Apps using game-based strategy have been created to teach and facilitate dermoscopy learning; however, studies are required to demonstrate their effectiveness. This review summarizes the current evidence of game-based learning strategies in medical education, including dermatology and dermoscopy.
Noninvasive modulation of predictive coding in humans: causal evidence for frequency-specific temporal dynamics
Authors: Draganov Metodi , Galiano-Landeira Jordi , Doruk Camsari Deniz , Ramírez Jairo-Enrique , Robles Marta , Chanes Lorena
Published: May 2023

Increasing evidence indicates that the brain predicts sensory input based on past experiences, importantly constraining how we experience the world. Despite a growing interest on this framework, known as predictive coding, most of such approaches to multiple psychological domains continue to be theoretical or primarily provide correlational evidence. We here explored the neural basis of predictive processing using noninvasive brain stimulation and provide causal evidence of frequency-specific modulations in humans. Participants received 20 Hz (associated with top-down/predictions), 50 Hz (associated with bottom-up/prediction errors), or sham transcranial alternating current stimulation on the left dorsolateral prefrontal cortex while performing a social perception task in which facial expression predictions were induced and subsequently confirmed or violated. Left prefrontal 20 Hz stimulation reinforced stereotypical predictions. In contrast, 50 Hz and sham stimulation failed to yield any significant behavioral effects. Moreover, the frequency-specific effect observed was further supported by electroencephalography data, which showed a boost of brain activity at the stimulated frequency band. These observations provide causal evidence for how predictive processing may be enabled in the human brain, setting up a needed framework to understand how it may be disrupted across brain-related conditions and potentially restored through noninvasive methods.
Laparoscopic ischemic conditioning prior esophagectomy in selected patients: the ISCON trial
Authors: de Groot Eline , Schiffmann Lars M , van der Veen Arjen , Borggreve Alicia , de Jong Pim , Dos Santos Daniel Pinto , Babic Benjamin , Fuchs Hans , Ruurda Jelle , Bruns Christiane , van Hillegersberg Richard , Schröder Wolfgang
Published: May 2023

Anastomotic leakage (AL) after esophagectomy is the most impactful complication after esophagectomy. Ischemic conditioning (ISCON) of the stomach >14 days prior to esophagectomy might reduce the incidence of AL. The current trial was conducted to prospectively investigate the safety and feasibility of laparoscopic ISCON in selected patients. This international multicenter feasibility trial included patients with esophageal cancer at high risk for AL with major calcifications of the thoracic aorta or a stenosis in the celiac trunk. Patients underwent laparoscopic ISCON by occlusion of the left gastric and the short gastric arteries followed by esophagectomy after an interval of 12–18 days. The primary endpoint was complications Clavien-Dindo ≥ grade 2 after ISCON and before esophagectomy. Between November 2019 and January 2022, 20 patients underwent laparoscopic ISCON followed by esophagectomy. Out of 20, 16 patients (80%) underwent neoadjuvant treatment. The median duration of the laparoscopic ISCON procedure was 45 minutes (range: 25–230). None of the patients developed intraoperative or postoperative complications after ISCON. Hospital stay after ISCON was median 2 days (range: 2–4 days). Esophagectomy was completed in all patients after a median of 14 days (range: 12–28). AL occurred in three patients (15%), and gastric tube necrosis occurred in one patient (5%). In hospital, the 30-day and 90-day mortalities were 0%. Laparoscopic ISCON of the gastric conduit is feasible and safe in selected esophageal cancer patients with an impaired vascular status. Further studies have to prove whether this innovative strategy aids to reduce the incidence of AL.
Artificial intelligence modelling to assess the risk of cardiovascular disease in oncology patients
Authors: Al-Droubi Samer S , Jahangir Eiman , Kochendorfer Karl M , Krive Marianna , Laufer-Perl Michal , Gilon Dan , Okwuosa Tochukwu M , Gans Christopher P , Arnold Joshua H , Bhaskar Shakthi T , Yasin Hesham A , Krive Jacob
Published: May 2023

Aims

There are no comprehensive machine learning (ML) tools used by oncologists to assist with risk identification and referrals to cardio-oncology. This study applies ML algorithms to identify oncology patients at risk for cardiovascular disease for referrals to cardio-oncology and to generate risk scores to support quality of care.

Methods and results

De-identified patient data were obtained from Vanderbilt University Medical Center. Patients with breast, kidney, and B-cell lymphoma cancers were targeted. Additionally, the study included patients who received immunotherapy drugs for treatment of melanoma, lung cancer, or kidney cancer. Random forest (RF) and artificial neural network (ANN) ML models were applied to analyse each cohort: A total of 20 023 records were analysed (breast cancer, 6299; B-cell lymphoma, 9227; kidney cancer, 2047; and immunotherapy for three covered cancers, 2450). Data were divided randomly into training (80%) and test (20%) data sets. Random forest and ANN performed over 90% for accuracy and area under the curve (AUC). All ANN models performed better than RF models and produced accurate referrals.

Conclusion

Predictive models are ready for translation into oncology practice to identify and care for patients who are at risk of cardiovascular disease. The models are being integrated with electronic health record application as a report of patients who should be referred to cardio-oncology for monitoring and/or tailored treatments. Models operationally support cardio-oncology practice. Limited validation identified 86% of the lymphoma and 58% of the kidney cancer patients with major risk for cardiotoxicity who were not referred to cardio-oncology.
Inverse association between apolipoprotein C-II and cardiovascular mortality: role of lipoprotein lipase activity modulation
Authors: Silbernagel Günther , Chen Yan Q , Rief Martin , Kleber Marcus E , Hoffmann Michael M , Stojakovic Tatjana , Stang Andreas , Sarzynski Mark A , Bouchard Claude , März Winfried , Qian Yue-Wei , Scharnagl Hubert , Konrad Robert J
Published: May 2023

Aims

Apolipoprotein C-II (ApoC-II) is thought to activate lipoprotein lipase (LPL) and is therefore a possible target for treating hypertriglyceridemia. Its relationship with cardiovascular risk has not been investigated in large-scale epidemiologic studies, particularly allowing for apolipoprotein C-III (ApoC-III), an LPL antagonist. Furthermore, the exact mechanism of ApoC-II–mediated LPL activation is unclear.

Methods and results

ApoC-II was measured in 3141 LURIC participants of which 590 died from cardiovascular diseases during a median (inter-quartile range) follow-up of 9.9 (8.7–10.7) years. Apolipoprotein C-II–mediated activation of the glycosylphosphatidylinositol high-density lipoprotein binding protein 1 (GPIHBP1)–LPL complex was studied using enzymatic activity assays with fluorometric lipase and very low-density lipoprotein (VLDL) substrates. The mean ApoC-II concentration was 4.5 (2.4) mg/dL. The relationship of ApoC-II quintiles with cardiovascular mortality exhibited a trend toward an inverse J-shape, with the highest risk in the first (lowest) quintile and lowest risk in the middle quintile. Compared with the first quintile, all other quintiles were associated with decreased cardiovascular mortality after multivariate adjustments including ApoC-III as a covariate (all P < 0.05). In experiments using fluorometric substrate-based lipase assays, there was a bell-shaped relationship for the effect of ApoC-II on GPIHBP1–LPL activity when exogenous ApoC-II was added. In ApoC-II-containing VLDL substrate-based lipase assays, GPIHBP1–LPL enzymatic activity was almost completely blocked by a neutralizing anti-ApoC-II antibody.

Conclusion

The present epidemiologic data suggest that increasing low circulating ApoC-II levels may reduce cardiovascular risk. This conclusion is supported by the observation that optimal ApoC-II concentrations are required for maximal GPIHBP1–LPL enzymatic activity.
Diversity of culturable bacteria of freshwater environments from an altitudinal gradient in the eastern Cordillera of Colombia
Authors: Suescun-Sepulveda Jhon Alexander , Rondón González Fernando , Fuentes Lorenzo Jorge Luis
Published: May 2023

Bacteria are an essential biotic component in freshwater environments. A group of 262 bacterial strains of freshwater environments from an altitudinal gradient in the Eastern Cordillera of Colombia was identified using the 16S rRNA gene sequence analysis. Hill numbers and related diversity indices were calculated to know the bacteria diversity in this collection and environments. In addition, the Bray–Curtis index was also calculated to know the differences in genera composition between sampled localities and their relationship with altitudinal gradient. The identified bacterial strains were grouped into 7 major phylogenetic groups (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Flavobacteriia, Actinomycetes, Clostridia, and Bacilli), 38 genera, and 84 distinctive species. Diversity analysis based on Hill numbers showed that the diversity concerning bacteria inhabiting freshwater environments was consistently high. Dominant genera were Klebsiella, Serratia, and Pseudomonas, although other genera such as Bacillus, Lelliottia, and Obesumbacterium were well represented per locality. The highest bacterial diversity came from localities Cimitarra and El Carmen del Chucurí, while those originating from Santa Bárbara and Páramo del Almorzadero were relatively lower diverse. Differences in diversity were found to be mainly due to the spatial replacement of one genus by another and, to a lesser extent, to the loss or gain of taxa.
Targeting the nucleotide metabolism of Trypanosoma brucei and other trypanosomatids
Authors: Hofer Anders
Published: May 2023

African sleeping sickness, Chagas disease, and leishmaniasis are life-threatening diseases that together affect millions of people around the world and are caused by different members of the protozoan family Trypanosomatidae. The most studied member of the family is Trypanosoma brucei, which is spread by tsetse flies and causes African sleeping sickness. Nucleotide metabolism in T. brucei and other trypanosomatids is significantly different from that of mammals and was recognized as a target for chemotherapy already in the 1970–1980s. A more thorough investigation of the nucleotide metabolism in recent years has paved the way for identifying nucleoside analogues that can cure T. brucei brain infections in animal models. Specific features of T. brucei nucleotide metabolism include the lack of de novo purine biosynthesis, the presence of very efficient purine transporters, the lack of salvage pathways for CTP synthesis, unique enzyme localizations, and a recently discovered novel pathway for dTTP synthesis. This review describes the nucleotide metabolism of T. brucei, highlights differences and similarities to other trypanosomatids, and discusses how to exploit the parasite-specific features for drug development.
Separating broad-band site response from single-station seismograms
Authors: Zhu Chuanbin , Cotton Fabrice , Kawase Hiroshi , Bradley Brendon
Published: May 2023

In this paper, we explore the use of seismicity data on a single-station basis in site response characterization. We train a supervised deep-learning model, SeismAmp, to recognize and separate seismic site response with reference to seismological bedrock (VS  = 3.45 km s−1) in a broad frequency range (0.2–20 Hz) directly from single-station earthquake recordings (features) in Japan. Ground-truth data are homogeneously created using a classical multistation approach—generalized spectral inversion at a total number of 1725 sites. We demonstrate that site response can be reliably separated from single-station seismograms in an end-to-end approach. When SeismAmp is tested at new sites in both Japan (in-domain) and Europe (cross-domain), it achieves the lowest standard deviation among all tested single-station techniques. We also find that horizontal-to-vertical spectral ratio (HVSR) is not the optimal use of single-station recordings. The individual components of each record carry salient information on site response, especially at high frequencies. However, part of the information is lost in HVSR. SeismAmp could lead to improved site-specific earthquake hazard prediction in cases where recordings are available or can be collected at target sites. It is also a convenient tool to remove repeatable site effects from ground motions, which may benefit other applications, for example, improving the retrieval of seismic source parameters. Finally, SeismAmp is trained on data from Japan, future studies could explore transfer learning for practical applications in other regions.
Time-domain Green’s function in poroelastic mediums and its application to 3-D spontaneous rupture simulation
Authors: Li Zhengze , Zhang Haiming
Published: May 2023

Plenty of studies have suggested that pore fluid may play an important role in earthquake rupture processes. Establishing numerical models can provide great insight into how pore fluid may affect earthquake rupture processes. However, numerical simulation of 3-D spontaneous ruptures in poroelastic mediums is still a challenging task. In this paper, it is found that a closed-form time-domain Green’s function of Biot’s poroelastodynamic model can be constructed when the source frequency and source-field distance are within a certain range. The time-domain Green’s function is validated by being transformed into the frequency domain and comparing with the frequency-domain Green’s functions obtained by former papers. Poroelastic wave propagation phase diagrams for various two-phase poroelastic mediums are then plotted to show the applicable range of frequency and source-field distance for the new time-domain Green’s function. It is shown that the applicable range not only include the frequency and spatial range of concern in seismology but also overlap that in acoustics. Based on the time-domain Green’s function, the boundary integral equations (BIEs) for modelling dynamic ruptures in elastic mediums are extended to fluid-saturated mediums. In the meantime, a functional relationship between the effective stress tensor and the total stress tensor in fluid-saturated mediums is also obtained, which allows us to directly obtain the effective stress by BIEs. The spontaneous rupture processes controlled by the slip-weakening friction law on faults in elastic mediums and in fluid-saturated mediums are compared. It is found that under the same conditions, fluid-saturated rocks are more prone to supershear rupture than dry rocks. This result suggests that pore fluid may promote the excitation of supershear rupture. The poroelastic wave propagation phase diagrams also suggest that simulating a coseismic phase in the real scale requires a certain sample length in laboratories. They also suggest that an undrained governing equation is suitable for seismic wave propagation simulation in poroelastic media.
Gene copy number variation and pediatric mental health/neurodevelopment in a general population
Authors: Zarrei Mehdi , Burton Christie L , Engchuan Worrawat , Higginbotham Edward J , Wei John , Shaikh Sabah , Roslin Nicole M , MacDonald Jeffrey R , Pellecchia Giovanna , Nalpathamkalam Thomas , Lamoureux Sylvia , Manshaei Roozbeh , Howe Jennifer , Trost Brett , Thiruvahindrapuram Bhooma , Marshall Christian R , Yuen Ryan K C , Wintle Richard F , Strug Lisa J , Stavropoulos Dimitri J , Vorstman Jacob A S , Arnold Paul , Merico Daniele , Woodbury-Smith Marc , Crosbie Jennifer , Schachar Russell J , Scherer Stephen W
Published: May 2023

We assessed the relationship of gene copy number variation (CNV) in mental health/neurodevelopmental traits and diagnoses, physical health and cognition in a community sample of 7100 unrelated children and youth of European or East Asian ancestry (Spit for Science). Clinically significant or susceptibility CNVs were present in 3.9% of participants and were associated with elevated scores on a continuous measure of attention-deficit/hyperactivity disorder (ADHD) traits (P = 5.0 × 10−3), longer response inhibition (a cognitive deficit found in several mental health and neurodevelopmental disorders; P = 1.0 × 10−2) and increased prevalence of mental health diagnoses (P = 1.9 × 10−6, odds ratio: 3.09), specifically ADHD, autism spectrum disorder anxiety and learning problems/learning disorder (P’s < 0.01). There was an increased burden of rare deletions in gene-sets related to brain function or expression in brain associated with more ADHD traits. With the current mental health crisis, our data established a baseline for delineating genetic contributors in pediatric-onset conditions.
Retirement and cardiovascular disease: a longitudinal study in 35 countries
Authors: Sato Koryu , Noguchi Haruko , Inoue Kosuke , Kawachi Ichiro , Kondo Naoki
Published: May 2023

Background

Many countries have been increasing their state pension age (SPA); nonetheless, there is little consensus on whether retirement affects the risk of cardiovascular disease (CVD). This study examined the associations of retirement with CVD and risk factors.

Methods

We used harmonized longitudinal datasets from the Health and Retirement Study and its sister surveys in 35 countries. Data comprised 396 904 observations from 106 927 unique individuals aged 50–70 years, with a mean follow-up period of 6.7 years. Fixed-effects instrumental variable regressions were performed using the SPA as an instrument.

Results

We found a 2.2%-point decrease in the risk of heart disease [coefficient = -0.022 (95% confidence interval: -0.031 to -0.012)] and a 3.0%-point decrease in physical inactivity [-0.030 (-0.049 to -0.010)] among retirees, compared with workers. In both sexes, retirement was associated with a decreased heart disease risk, whereas decreased smoking was observed only among women. People with high educational levels showed associations between retirement and decreased risks of stroke, obesity and physical inactivity. People who retired from non-physical labour exhibited reduced risks of heart disease, obesity and physical inactivity, whereas those who retired from physical labour indicated an increased risk of obesity.

Conclusions

Retirement was associated with a reduced risk of heart disease on average. Some associations of retirement with CVD and risk factors appeared heterogeneous by individual characteristics.
Chemical reaction and activation energy on heat and mass transfer for convective flow along an inclined surface in Darcy porous medium with Soret and Dufour effects
Authors: Huang J S
Published: May 2023

This study investigated the heat and mass that are transferred when a fluid undergoes convective flow along an inclined plate through a porous medium and also considered the corresponding chemical reaction and activation energy. The influences of the variable viscosity, mixed convection intensity, inclination angle, thermal radiation, magnetic field, internal heat source, activation energy, chemical reaction and Soret and Dufour effects for fluid flowing through a Darcy porous medium are all discussed. Numerical techniques, namely Runge–Kutta integration and the shooting method, were applied to obtain solutions to similarity-transformed equations governing continuity, momentum, energy and concentration. The study examined the distributions of flow velocity, temperature and concentration under the interactive effects of the fluid. The results revealed that the activation energy of the Arrhenius equation plays an important role in fluid transport mechanisms within a chemically reactive system involving the Soret and Dufour effects for a low-Schmidt-number fluid. When the activation energy parameter E was greater within the range 0 < E < 5, the wall shear stress was stronger, heat transfer rate increased, and mass transfer rate decreased.
Synthetic developmental biology: molecular tools to re-design plant shoots and roots
Authors: Kocaoglan Elif Gediz , Radhakrishnan Dhanya , Nakayama Naomi
Published: May 2023

Plant morphology and anatomy strongly influence agricultural yield. Crop domestication has strived for desirable growth and developmental traits, such as larger and more fruits and semi-dwarf architecture. Genetic engineering has accelerated rational, purpose-driven engineering of plant development, but it can be unpredictable. Developmental pathways are complex and riddled with environmental and hormonal inputs, as well as feedback and feedforward interactions, which occur at specific times and places in a growing multicellular organism. Rational modification of plant development would probably benefit from precision engineering based on synthetic biology approaches. This review outlines recently developed synthetic biology technologies for plant systems and highlights their potential for engineering plant growth and development. Streamlined and high-capacity genetic construction methods (Golden Gate DNA Assembly frameworks and toolkits) allow fast and variation-series cloning of multigene transgene constructs. This, together with a suite of gene regulation tools (e.g. cell type-specific promoters, logic gates, and multiplex regulation systems), is starting to enable developmental pathway engineering with predictable outcomes in model plant and crop species.
Signatures of wakefield acceleration in astrophysical jets via gamma-rays and UHECRs
Authors: Huxtable Gregory B , Eltawil Noor , Feng Wei-Xiang , Player Gabriel , Wang Wenhao , Tajima Toshiki , Ebisuzaki Toshikazu
Published: May 2023

We present six case studies from a comprehensive mass range (1–109 M⊙) of astrophysical objects, each of which possess jets, emit high-energy gamma radiation and in some instances spatially identifiable ultra-high-energy cosmic rays (UHECRs). All sources are strong candidates for UHECR emission, if not already known to emit them. We surmise that wakefield acceleration in conjunction with the magnetorotational instability of the accretion disc explains both structural properties of the jets and details in their emission signals, such as correlations in neutrino and gamma-ray bursts, and in the case of blazars, anticorrelations in flux and spectral index. Furthermore, our model predicts an upper bound for the energy of UHECRs emitted from a source given the mass of its central compact object and total jet luminosity. To provide context for our model predictions, we quantitatively compare them with observational data, however, we have not accounted for the GZK limit and assumed universal values for several model parameters (e.g. jet-spreading index, p) that likely differ between sources. Since the accretion and acceleration mechanisms are independent of mass, aside from determining maximum values, blazars (∼109 M⊙), radio galaxies ($\sim 10^8\, {\rm M}_{\odot }$ ), Seyfert galaxies ($\sim 10^6 \, {\rm M}_{\odot }$ ), starburst galaxies ($\sim 10^{3}\, {\rm M}_{\odot }$ ), even microquasars (1–10 M⊙) interestingly exhibit the same physics. Other radiation bands, such as X-ray, ultraviolet, or radio, may harbour additional information, but we chose not to focus on them for brevity. However, such an endeavour may open the door to a new multimessenger approach for understanding these objects.
An X-ray spectroscopy study of structural stability of superhydrogenated pyrene derivatives
Authors: Huo Yining , Espinoza Cangahuala Mónica K , Zamudio-Bayer Vicente , Goulart Marcelo , Kubin Markus , Timm Martin , Lau J Tobias , von Issendorff Bernd , Hoekstra Ronnie , Faraji Shirin , Schlathölter Thomas
Published: May 2023

The stability of polycyclic aromatic hydrocarbons (PAHs) upon soft X-ray absorption is of crucial relevance for PAH survival in X-ray dominated regions. PAH stability depends on molecular size but also on the degree of hydrogenation that is related to H2 formation in the interstellar medium. In this project, we intend to reveal the changes of electronic structure caused by hydrogenation and the impact of hydrogenation on the stability of the carbon backbone for cationic pyrene and its hydrogenated derivatives by analysis of near C K-edge soft X-ray photoions. In our experiments, the PAH cations were trapped in a cryogenic radiofrequency linear ion trap and exposed to monochromatic X-rays with energies from 279 to 300 eV. The photoproducts were mass-analysed by means of time-of-flight spectroscopy. Partial ion yields were then studied as a function of photon energy. X-ray absorption spectra computed by time-dependent density functional theory (TD-DFT) aided the interpretation of the experimental results. A very good agreement between experimental data and TD-DFT with short-range corrected functionals for all PAH ions was reached. The near-edge X-ray absorption mass spectra exhibit clear peaks due to C 1s transitions to singly occupied molecular orbitals and to low-lying unoccupied molecular orbitals. In contrast to coronene cations, where hydrogen attachment drastically increases photostability of coronene, the influence of hydrogenation on photostability is substantially weaker for pyrene cations. Here, hydrogen attachment even destabilizes the molecular structure. An astrophysical model describes the half-life of PAH ions in interstellar environments.
Bimodal star formation in simulations of strongly magnetized giant molecular clouds
Authors: Hix Ronan , He Chong-Chong , Ricotti Massimo
Published: May 2023

We present the results of a set of radiation magnetohydrodynamic simulations of turbulent molecular clouds in which we vary the initial strength of the magnetic field within a range (1 ≲ μ ≲ 5) consistent with observations of local giant molecular clouds (GMCs). We find that as we increase the strength of the magnetic field, star formation transitions from unimodal (the baseline case, μ = 5, with a single burst of star formation and Salpeter IMF) to bimodal. This effect is clearest in the most strongly magnetized GMC (μ = 1): a first burst of star formation with duration, intensity, and IMF comparable to the baseline case, is followed by a second star formation episode in which only low-mass stars are formed. Overall, due to the second burst of star formation, the strongly magnetized case results in a longer star formation period and a higher efficiency of star formation. The second burst is produced by gas that is not expelled by radiative feedback, instead remains trapped in the GMC by the large-scale B-field, producing a nearly one-dimensional flow of gas along the field lines. The trapped gas has a turbulent and magnetic topology that differs from that of the first phase and strongly suppresses gas accretion onto protostellar cores, reducing their masses. We speculate that this star formation bimodality may be an important ingredient to understand the origin of multiple stellar populations observed in massive globular clusters.
Local Group dwarf galaxy detection limit in the CSST survey
Authors: Qu Han , Yuan Zhen , Doliva-Dolinsky Amandine , Martin Nicolas F , Kang Xi , Wei Chengliang , Li Guoliang , Luo Yu , Chang Jiang , Tsai Chaowei , Fan Zhou , Ibata Rodrigo
Published: May 2023

We predict the dwarf galaxy detection limits for the upcoming Chinese Space Station Telescope (CSST) survey that will cover 17 500 ${\rm \, deg}^{2}$ of the sky with a wide field of view of 1.1 deg2. The point-source depth reaches 26.3 mag in the g band and 25.9 mag in the i band. Constructing mock survey data based on the designed photometric bands, we estimate the recovery rate of artificial dwarf galaxies from mock point-source photometric catalogues. The detection of these artificial dwarf galaxies is strongly dependent on their distance, magnitude, and size, in agreement with searches in current surveys. We expect CSST to enable the detection of dwarf galaxies with MV = −3.0 and μ250 = 32.0 mag arcsec−2 (surface brightness limit for a system of half-light radius rh = 250 ${\rm \, pc}$) at $400 {\rm \, kpc}$, and MV = −4.9 and μ250 = 30.5 mag arcsec−2 around the Andromeda galaxy. Beyond the Local Group, the CSST survey will achieve MV = −5.8, and μ250 = 29.7 mag arcsec−2 in the distance range of 1–2 Mpc, opening up an exciting discovery space for faint field dwarf galaxies. With its optical bands, wide survey footprint, and space resolution, CSST will undoubtedly expand our knowledge of low-mass dwarf galaxies to an unprecedented volume.
Satellites of Milky Way- and M31-like galaxies with TNG50: quenched fractions, gas content, and star formation histories
Authors: Engler Christoph , Pillepich Annalisa , Joshi Gandhali D , Pasquali Anna , Nelson Dylan , Grebel Eva K
Published: May 2023

We analyse the quenched fractions, gas content, and star formation histories of ∼1200 satellite galaxies with M* ≥ 5 × 106 M⊙ around 198 Milky Way- (MW) and Andromeda-like (M31) hosts in TNG50, the highest-resolution simulation of IllustrisTNG. Satellite quenched fractions are larger for smaller masses, for smaller distances to their host galaxy, and in the more massive M31-like compared to MW-like hosts. As satellites cross their host’s virial radius, their gas content drops: Most satellites within 300 kpc lack detectable gas reservoirs at z = 0, unless they are massive like the Magellanic Clouds and M32. Nevertheless, their stellar assembly exhibits a large degree of diversity. On average, the cumulative star formation histories are more extended for brighter, more massive satellites with a later infall, and for those in less massive hosts. Based on these relationships, we can even infer infall periods for observed MW and M31 dwarfs, e.g. 0–4 Gyr ago for the Magellanic Clouds and Leo I, and 4–8 and 0–2 Gyr ago for M32 and IC 10, respectively. Ram pressure stripping (in combination with tidal stripping) deprives TNG50 satellites of their gas reservoirs and ultimately quenches their star formation, even though only a few per cent of the present-day satellites around the 198 TNG50 MW/M31-like hosts appear as jellyfish. The typical time since quenching for currently quenched TNG50 satellites is $6.9\substack{+2.5\\-3.3}$ Gyr ago. The TNG50 results are consistent with the quenched fractions and stellar assembly of observed MW and M31 satellites, however, satellites of the SAGA survey with M* ∼ 108–109 M⊙ exhibit lower quenched fractions than TNG50 and other, observed analogues.
The spatial correlation of high-mass X-ray binaries and young star clusters in nearby star-forming galaxies
Authors: Binder Breanna A , Anderson Ashley K , Garofali Kristen , Lazzarini Margaret , Williams Benjamin F
Published: May 2023

We present an analysis of the two-point spatial correlation functions of high-mass X-ray binary (HMXB) and young star cluster (YSC) populations in M31 and M33. We find evidence that HMXBs are spatially correlated with YSCs to a higher degree than would be expected from random chance in both galaxies. When supplemented with similar studies in the Milky Way, Small Magellanic Cloud, and NGC 4449, we find that the peak value of the spatial correlation function correlates strongly with the specific star formation rate of the host galaxy. We additionally perform an X-ray stacking analysis of 211 non-X-ray detected YSCs in M31 and 463 YSCs in M33. We do not detect excess X-ray emission at the stacked cluster locations down to 3σ upper limits of ∼1033 erg s−1 (0.35–8 keV) in both galaxies, which strongly suggests that dynamical formation within YSCs is not a major HMXB formation channel. We interpret our results in the context of (1) the recent star formation histories of the galaxies, which may produce differences in the demographics of compact objects powering the HMXBs, and (2) the differences in natal kicks experienced by compact objects during formation, which can eject newly formed HMXBs from their birth clusters.
Hydrodynamical structure formation in Milgromian cosmology
Authors: Wittenburg Nils , Kroupa Pavel , Banik Indranil , Candlish Graeme , Samaras Nick
Published: May 2023

We present the first hydrodynamical cosmological simulations in the νHDM framework based on Milgromian dynamics (MOND) with light (11 eV) sterile neutrinos. νHDM can explain the expansion history, CMB anisotropies, and galaxy cluster dynamics similarly to standard cosmology while preserving MOND’s successes on galaxy scales, making this the most conservative Milgromian framework. We generate initial conditions including sterile neutrinos using camb and music and modify the publicly available code phantom of ramses to run νHDM models. The simulations start at redshift $z_e$ = 199, when the gravitational fields are stronger than $a_{_0}$ provided this does not vary. We analyse the growth of structure and investigate the impact of resolution and box size, which is at most 600 comoving Mpc. Large density contrasts arise at late times, which may explain the KBC void and Hubble tension. We quantify the mass function of formed structures at different redshifts. We show that the sterile neutrino mass fraction in these structures is similar to the cosmic fraction at high masses (consistent with MOND dynamical analyses) but approaches zero at lower masses, as expected for galaxies. We also identify structures with a low peculiar velocity comparable to the Local Group, but these are rare. The onset of group/cluster-scale structure formation at $z_e$ ≈ 4 appears to be in tension with observations of high redshift galaxies, which we discuss in comparison to prior analytical work in a MONDian framework. The formation of a cosmic web of filaments and voids demonstrates that this is not unique to standard Einstein/Newton-based cosmology.
SKA Science Data Challenge 2: analysis and results
Authors: Hartley P , Bonaldi A , Braun R , Aditya J N H S , Aicardi S , Alegre L , Chakraborty A , Chen X , Choudhuri S , Clarke A O , Coles J , Collinson J S , Cornu D , Darriba L , Veneri M Delli , Forbrich J , Fraga B , Galan A , Garrido J , Gubanov F , Håkansson H , Hardcastle M J , Heneka C , Herranz D , Hess K M , Jagannath M , Jaiswal S , Jurek R J , Korber D , Kitaeff S , Kleiner D , Lao B , Lu X , Mazumder A , Moldón J , Mondal R , Ni S , Önnheim M , Parra M , Patra N , Peel A , Salomé P , Sánchez-Expósito S , Sargent M , Semelin B , Serra P , Shaw A K , Shen A X , Sjöberg A , Smith L , Soroka A , Stolyarov V , Tolley E , Toribio M C , van der Hulst J M , Sadr A Vafaei , Verdes-Montenegro L , Westmeier T , Yu K , Yu L , Zhang L , Zhang X , Zhang Y , Alberdi A , Ashdown M , Bom C R , Brüggen M , Cannon J , Chen R , Combes F , Conway J , Courbin F , Ding J , Fourestey G , Freundlich J , Gao L , Gheller C , Guo Q , Gustavsson E , Jirstrand M , Jones M G , Józsa G , Kamphuis P , Kneib J-P , Lindqvist M , Liu B , Liu Y , Mao Y , Marchal A , Márquez I , Meshcheryakov A , Olberg M , Oozeer N , Pandey-Pommier M , Pei W , Peng B , Sabater J , Sorgho A , Starck J L , Tasse C , Wang A , Wang Y , Xi H , Yang X , Zhang H , Zhang J , Zhao M , Zuo S
Published: May 2023

The Square Kilometre Array Observatory (SKAO) will explore the radio sky to new depths in order to conduct transformational science. SKAO data products made available to astronomers will be correspondingly large and complex, requiring the application of advanced analysis techniques to extract key science findings. To this end, SKAO is conducting a series of Science Data Challenges, each designed to familiarize the scientific community with SKAO data and to drive the development of new analysis techniques. We present the results from Science Data Challenge 2 (SDC2), which invited participants to find and characterize 233 245 neutral hydrogen (H i) sources in a simulated data product representing a 2000 h SKA-Mid spectral line observation from redshifts 0.25–0.5. Through the generous support of eight international supercomputing facilities, participants were able to undertake the Challenge using dedicated computational resources. Alongside the main challenge, ‘reproducibility awards’ were made in recognition of those pipelines which demonstrated Open Science best practice. The Challenge saw over 100 participants develop a range of new and existing techniques, with results that highlight the strengths of multidisciplinary and collaborative effort. The winning strategy – which combined predictions from two independent machine learning techniques to yield a 20 per cent improvement in overall performance – underscores one of the main Challenge outcomes: that of method complementarity. It is likely that the combination of methods in a so-called ensemble approach will be key to exploiting very large astronomical data sets.
Photometric IGM tomography with Subaru/HSC: the large-scale structure of Lyαemitters and IGM transmission in the COSMOS field atz˜ 5
Authors: Kakiichi Koki , Hennawi Joseph F , Ono Yoshiaki , Inoue Akio K , Ouchi Masami , Ellis Richard S , Meyer Romain A , Bosman Sarah I
Published: May 2023

We present a novel technique called ‘photometric IGM tomography’ to map the intergalactic medium (IGM) at z ≃ 4.9 in the COSMOS field. It utilizes deep narrow-band (NB) imaging to photometrically detect faint Ly α forest transmission in background galaxies across the Subaru/Hyper-Suprime Cam (HSC)’s $1.8\rm \, sq.\, deg$ field of view and locate Ly α emitters (LAEs) in the same cosmic volume. Using ultra-deep HSC images and Bayesian spectral energy distribution fitting, we measure the Ly α forest transmission at z ≃ 4.9 along a large number (140) of background galaxies selected from the DEIMOS10k spectroscopic catalogue at 4.98 < z < 5.89 and the SILVERRUSH LAEs at z ≃ 5.7. We photometrically measure the mean Ly α forest transmission and achieve a result consistent with previous measurements based on quasar spectra. We also measure the angular LAE-Ly α forest cross-correlation and Ly α forest autocorrelation functions and place an observational constraint on the large-scale fluctuations of the IGM around LAEs at z ≃ 4.9. Finally, we present the reconstructed 2D tomographic map of the IGM, co-spatial with the large-scale structure of LAEs, at a transverse resolution of $11 \, h^{-1}\rm cMpc$ across $140\, h^{-1}\rm cMpc$ in the COSMOS field at z ≃ 4.9. We discuss the observational requirements and the potential applications of this new technique for understanding the sources of reionization, quasar radiative history, and galaxy–IGM correlations across z ∼ 3–6. Our results represent the first proof-of-concept of photometric IGM tomography, offering a new route to examining early galaxy evolution in the context of the large-scale cosmic web from the epoch of reionization to cosmic noon.
Synchrotron intensity plots from a relativistic stratified jet
Authors: Frolova V A , Nokhrina E E , Pashchenko I N
Published: May 2023

We examine the effect of a jet transversal structure from magnetohydrodynamic semi-analytical modelling on the total intensity profiles of relativistic jets from active galactic nuclei. In order to determine the conditions for forming double- and triple-peaked transverse intensity profiles, we calculate the radiative transfer for synchrotron emission with self-absorption from the jets described by the models with a constant angular velocity and with a total electric current closed inside a jet. We show that double-peaked profiles appear either in the models with high maximal Lorentz factors or in optically thick conditions. We show that triple-peaked profiles in radio galaxies constrain the fraction of the emitting particles in a jet. We introduce the possible conditions for triple-peaked profiles under the assumptions that non-thermal electrons are preferably located at the jet edges or are distributed according to Ohmic heating.
ALMA High-Level Data Products: submillimetre counterparts of SDSS quasars in the ALMA footprint
Authors: Wong A , Hatziminaoglou E , Borkar A , Popping G , Pérez-Fournon I , Poidevin F , Stoehr F , Messias H
Published: May 2023

The Atacama Large Millimetre/submillimetre Array (ALMA) is the world’s most advanced radio interferometric facility, producing science data with an average rate of about 1 TB per day. After a process of calibration, imaging and quality assurance, the scientific data are stored in the ALMA Science Archive (ASA), along with the corresponding raw data, making the ASA an invaluable resource for original astronomical research. Due to their complexity, each ALMA data set has the potential for scientific results that go well beyond the ideas behind the original proposal that led to each observation. For this reason, the European ALMA Regional Centre initiated the High-Level Data Products initiative to develop science-oriented data products derived from data sets publicly available in the ASA, that go beyond the formal ALMA deliverables. The first instance of this initiative is the creation of a catalogue of submillimetre (submm) detections of Sloan Digital Sky Survey (SDSS) quasars from the SDSS Data Release 14 that lie in the aggregate ALMA footprint observed since ALMA Cycle 0. The ALMA fluxes are extracted in an automatic fashion, using the ALMA Data Mining Toolkit. All extractions above a signal-to-noise cut of 3.5 are considered, they have been visually inspected and the reliable detections are presented in a catalogue of 376 entries, corresponding to 275 unique quasars. Interesting targets found in the process, i.e. lensed or jetted quasars as well as quasars with nearby submm counterparts are highlighted, to facilitate further studies or potential follow up observations.
Testing black hole mimickers with the Event Horizon Telescope image of Sagittarius A*
Authors: Shaikh Rajibul
Published: May 2023

The Event Horizon Telescope (EHT) has recently observed the image and shadow of the supermassive compact object Sagittarius A* (Sgr A*). According to the EHT collaboration, the observed image is consistent with the expected appearance of a Kerr black hole. However, it is well-known that some non-Kerr objects may mimic many of the properties of the Kerr black hole, and hence, their shadows might be consistent with the observed shadow of Sgr A*. In this work, we consider two black hole mimickers and study their shadows. The first mimicker is a rotating generalization of the recently proposed static, spherically symmetric black-bounce space–time by Simpson and Visser where the central Schwarzschild singularity is replaced by a minimal surface. The second one is the γ-metric which is a static, axially-symmetric singular solution of the vacuum Einstein’s equations without an event horizon. We put constraint on the parameters of these black hole mimickers by comparing their shadows with the observed shadow of Sgr A*.
Constraints on f(T) cosmology with Pantheon+
Authors: Briffa Rebecca , Escamilla-Rivera Celia , Said Jackson Levi , Mifsud Jurgen
Published: May 2023

f(T) cosmology has shown promise in explaining aspects of cosmic evolution. In this work, we analyse constraints on leading models of f(T) gravity in the context of the recently released Pantheon+ data set, together with comparisons with previous releases. We also consider other late time data sets including cosmic chronometers and baryonic acoustic oscillation data. Our main result is that we find that the different f(T) models under investigation connect to a variety of Hubble constant, which may help alleviate the cosmic tension on this parameter.