bluuebunny/crossref_metadata_2025 huggingface dataset:
5 Water Spray Attenuates Increases in Core Temperature During Physical Activity in Well-healed Burn Survivors
Authors: Crandall Craig G , Palmieri Tina L , Atkins Whitley , Foster Josh , McKenna Zachary , Belval Luke , Orth Bonnie , Watso Joseph
Published: April 2024

Introduction

Burn injuries that require grafting impair thermoregulation, and the accompanying heightened increases in skin and core temperatures may dissuade burn injury survivors from engaging in physical activity that is beneficial for their full rehabilitation as well as cardio-metabolic health. Low-energy (i.e., non-air conditioning) cooling modalities may attenuate increases in core temperature in burn survivors, but this question has not been examined. Thus, the purpose of this study is to test the hypothesis that low-energy cooling modalities will attenuate increases in core temperature during physical activity in the heat in well-healed burn survivors.

Methods

Adults with no burn injuries (non-burned; n=10), 20-40% body surface area severely burned (n=11), and >40% body surface area severely burned (n=10) walked on a treadmill for 1 hour at a low intensity (2.5 ± 0.2 mph and 2% grade) in a warm environmental chamber (39°C, 40% relative humidity). Burn survivors were at least 2 years post-injury. Testing was performed on four occasions, with the following cooling modalities applied throughout each trial (random trial order): no cooling, fan at 4 m/s (FAN), 10-50 g of water sprayed every 5 min (Water Spray; scaled to burn area size), or a combination of Water Spray+FAN. Rectal or gastrointestinal temperature (Tcore) was recorded throughout each trial.

Results

None of the cooling modalities affected Tcore for the non-burned (p=0.61) or the 20-40% burn (p=0.45) groups. Moreover, FAN and Water Spray+FAN did not impact end-exercise Tcore for the >40% burn group (p≥0.48). However, in the >40% burn group Water Spray reduced end-exercise Tcore by 0.34°C (0.12 to 0.56°C) when compared with no cooling (p = 0.004).

Conclusions

At the assessed workload and environmental condition, the efficacy of the applied cooling modalities on Tcore responses of burn survivors is dependent on both the selected modality and the size of the burn injury. Namely, there was no evidence that FAN or Water Spray+FAN attenuated Tcore responses regardless of the burn size, while Water Spray was effective at attenuating the elevation in Tcore in those with >40% burn injuries.

Applicability of Research to Practice

These data demonstrate that skin wetting, via frequent water spraying, is effective in attenuating elevations in Tcore during physical activity in warm and humid conditions in individuals with large burn injuries. Thus, water spray may be useful to encourage such burn survivors to engage in physical activity that is beneficial for their full rehabilitation as well as cardio-metabolic health.
721 The Role of Circadian Rhythms in Burn Injuries and Outcomes
Authors: Lerman Sheera F , Smith Lisa C , Khan Iman F , Mei Michelle , Lagziel Tomer , Cox Carrie A , Caffrey Julie A
Published: April 2024

Introduction

Circadian rhythms are patterns responsible for physiological and behavioral changes in living organisms that follow a 24-hour cycle. Burn injuries trigger an inflammatory response which is also regulated by the circadian system. Literature on the impact of circadian rhythms on burn injury outcomes remains scarce. However, there is evidence that the migration of cells involved in the wound healing process is circadian-regulated and that the timing of the burn injury in a 24-hour period is associated with wound healing rates in burn patients. The goal of this study was to explore the relationship between time of burn injury and burn related outcomes.

Methods

A retrospective chart review was conducted of 442 adult burn patients admitted to the Burn Center between January 2015 and February 2022. Mean age on admission was 50.13 years, 34% were female and patients identified as Caucasian (57%), African American (35%) or other (8%). Mean TBSA was 12.85%. Data on clinical and demographic factors and times of injury were extracted from patients’ electronic medical records. Times of burn injury were categorized as daytime versus nighttime based on local sunrise and sunset times.

Results

Fifty-seven percent of patients were burned during daytime. When comparing those who were burned at daytime to those burned at nighttime, daytime burns had lower %TBSA, shorter length of stay and lower morphine equivalent dose during their admission to the burn center. In a regression analysis predicting morphine equivalent dose, time of burn remained a statistically significant predictor, even after controlling for %TBSA, length of stay, gender, race, and age.

Conclusions

Our study underscores the pivotal role of burn injury timing, revealing that nighttime burns are correlated with adverse outcomes, even after accounting for other contributing factors. This insight has profound implications for optimizing burn care and developing targeted intervention strategies. While it is possible that nighttime burns are more severe and thus are associated with poorer outcomes, we found that even when controlling for burn size, nighttime burns have higher inpatient opioid requirements. This is consistent with evidence from human and animal models suggesting that the timing of a burn injury has a unique impact on circadian rhythm, which regulates a host of immune-related responses and can influence the healing process and opioid metabolism.

Applicability of Research to Practice

Recognizing the time of burn injury as a significant risk can enhance clinical assessment protocols, aiding in the identification of high-risk patients. It is crucial to pursue further research to understand the biological mechanism through which timing of injury interacts with circadian function to influence burn recovery.
762 Improving Pain Management During Burn Wound Care Procedures
Authors: Sheaffer Jason , Hutson Monica , Wolf Steven E , Jimenez Carlos , Forest Sharron
Published: April 2024

Introduction

During burn wound care, the intention is to manage pain throughout the procedure with minimal to no sedation. While it is rare that burn patients experience zero pain, 25% of patients were experiencing excessive pain with self-reported pain scores of ≥7 throughout their procedure. Identified gaps included nursing documentation of intra-procedure pain scores and provider variability on pain management.

Methods

A multidisciplinary Pain Management Task Force developed a Pain Management Guideline (PMG) comprised of frequent pain assessment, nonpharmacologic techniques, and pharmacologic therapy of nonopioids, opioids, and sedation. The established PMG consisted of a pain assessment at the start of the procedure, repeating every 15 minutes until procedure completion. Music therapy provided distraction at the patient’s discretion. Nitrous oxide utilization provided a nonopioid intervention. Building an order set allowed PMG incorporation into the electronic health record (EHR).

Results

Within 20 weeks, the percentage of patients with a mean procedural pain score of ≥7 reduced from 25% to 21%, short of the intended goal of 15%. The predominant approach to pain management remains the use of narcotic opioids. There was low usage of nitrous oxide with the unanticipated high prevalence of exclusionary factors of NPO compliance, facial trauma, and impairment. However, nitrous oxide was effective 90% of the time in reducing pain scores to < 7. Moderate sedation procedures proved a challenge in case coordination while maintaining regulatory compliance. Nursing documentation of pain scores improved by 79% after modification of the standard nursing note to include an intra-procedure pain assessment, which also increased the average number of pain assessments from 2 to 3. Encouragingly, PMG implementation did not increase the average procedure time or patient safety events.

An unanticipated finding was the presence and impact of Social Determinants of Health (SDOH) on pain perception and management. Of the patients reporting excessive pain, several had a pre-procedural pain score ≥7, which remained elevated throughout the intra- and post-procedure intervals. Positive SDOH factors identified included a significant history of substance abuse, homelessness, poverty, and mental health disease.

Conclusions

Pain management principles were codified and organized into a PMG. Development and implementation of a PMG decreased self-reported pain scores for burn patients. The guideline improved pain management consistency between providers and improved nurses’ assessment and documentation of pain scores. When considering the practical implications, it is essential to understand how SDOH may impact pain management throughout all stages of care for burn patients.

Applicability of Research to Practice

A quality improvement project to reduce the rate of mean self-reported procedural pain scores of ≥7 during burn wound care procedures.
781 Visual Representation of Race and Skin Tones in North American Burn Literature
Authors: Kneib Cameron J , Shor Ryann E , Pham Tam N , Stewart Barclay T
Published: April 2024

Introduction

Representation of all people in the medical literature enhances our collective ability to practice health equity and avoid implicit bias in patient evaluation, treatment, and outcomes determination. Clinical photographs play an important role in evaluation of burn care and its outcomes. Prior research has shown disparities of photographic representation of minorities in surgical literature. Our aim was to sample diversity of skin color in images from burn journals to represent diversity of patients in the current burn literature from high-income North American countries (NA).

Methods

A bibliometric analysis was performed on three leading burn surgery journals between 2021-2023. Each report was reviewed by two independent reviewers to evaluate medical images depicting native human skin and location of corresponding author. Images and number of distinct individuals (for figures containing multiple photos of the same individual) were tabulated and categorized as Fitzpatrick Scale ◻3 (White/fair skin tone) or >3 (non-White/dark skin tone).

Results

A total of 353 articles in the Journal of Burn Care and Research, Burns, European Burn Journal with a corresponding author based in NA were reviewed for the study period, of which 45 (13%) articles contained images of native human skin. Analysis showed 216 photos depicting White/fair skin tone (60%) in 52 individuals (52%), whereas 144 photos depicted non-White/dark skin tone (40%) in 35 individuals (35%). This proportion is comparable to published American Burn Association factsheets for incidence of burns in non-White/non-Caucasian (41%).

Conclusions

Current images of non-White race/skin tone in burn literature from high-income North American countries indicate proportional race representation compared to NA burn injury demographics. Thoughtful and more intentional use of photographs depicting diverse skin tones improves representation within the field of burn care.

Applicability of Research to Practice

Greater awareness and intentional use of diverse skin tones in publication photographs are important for equity.
804 First-in-Human Xenotransplantation US-FDA-Clinical Trials - Complete Wound Closure of Mixed-Depth Burns via Porcine Skin Xenotransplant
Authors: Homsombath Bounthavy F , Holzer Paul , Rogers Kaitlyn M , Doloff Joshua C , Gullans Steve , Kaiser Robert A , Swartz Harold , Cetrulo, Jr. Curtis L , Scobie Linda , Monroy Rod , Goverman Jeremy
Published: April 2024

Introduction

Currently there is no treatment than can provide complete and durable wound closure of mixed-depth burn injuries, other than intact human skin, which has several drawbacks. An alternative would be a significant advancement in burn care and a meaningful benefit to patient care.

We report here the results of the first-in-human, US-FDA xenotransplantation clinical trial: the use of skin xenotransplants containing live (i.e., non-terminally sterilized, non-xenograft) epidermal and dermal tissues derived from genetically altered, pathogen-free porcine donors to provide complete and durable wound closure of mixed-depth burn wounds.

Methods

22 patients with mixed-depth burn wounds were enrolled in Phase 1/2/2b US-FDA clinical trials to evaluate the safety and efficacy of skin xenotransplants to provide complete and durable wound closure in a side-by-side comparison with human allograft.

Results

To date, there have been zero adverse events including any xeno-related pathologies. In all patients, complete and durable wound closure was demonstrated at all xeno-treatment sites. In 3 cases, mixed-depth burns treated with the skin xenotransplant did not require autografting.

Conclusions

These clinical data demonstrate the ability of a live, genetically altered skin xenotransplant to facilitate complete and durable wound closure in mixed-depth burn wounds, and that the use of skin xenotransplants may potentially reduce the need for autografting in the treatment of mixed-depth burns. These claims will be evaluated in a US-FDA Phase 3 clinical trial.

Applicability of Research to Practice

First-in-Human Xenotransplant; Complete, Durable Wound Closure of Mixed, Depth, Full-Thickness Burn Wounds.
Unfolding some numerical solutions for the magnetohydrodynamics Casson–Williamson nanofluid flow over a stretching surface
Authors: Khan Kashif Ali , Vivas-Cortez Miguel , Ahammad N Ameer , Bushra Hafiza , Gamaoun Fehmi , Javed Muhammad Faraz , Raza Nauman
Published: April 2024

This research focuses on exploring the significance of chemical reactions and thermal radiation on the magnetohydrodynamic (MHD) flow of a Casson–Williamson nanofluid (CWNF) over a stretching sheet. The objective is to comprehend how these factors influence the flow and heat transfer. A mathematical model, comprising partial differential equations adjusted into ordinary differential equations (ODEs) via utilizing some transformation. These ODEs are then tackled by MATLAB’s BVP4C method, which is part of the finite difference technique. Results are verified by comparison with existing literature and are depicted visually and in tabular format. Additionally, the study explores the effects of external factors such as magnetic fields and the Lewis number on parameters like Nusselt number, friction factor, and Sherwood number. Furthermore, heat generation in MHD CWNF is analyzed, along with a thorough evaluation of heat transfer near a stretching sheet with a permeable layer. The findings suggest that growing Brownian motion factor (Nb) and thermophoresis coefficient (Nt) enhance the rate of heat transfer, signifying improved heat transfer rates. Similarly, higher Nt values are associated with enhanced Sherwood numbers, indicating better mass transfer. Conversely, higher Nb values lead in lower local Sherwood numbers. Physically, an increase in Brownian motion causes significant displacement of nanofluid particles, boosting their kinetic energy and thereby enhancing heat generation within the boundary layer. It is noted that the Eckert number (Ec) reflects the impact of different Ec values on temperature distribution. As Ec increases, there is a proportional increase in fluid temperature due to frictional heating, which stores heat energy within the fluid. This effect becomes more pronounced for non-linear stretching surfaces, demonstrating the response of the thermal region to viscous dissipation. Viscous dissipation has the potential to enhance convective heat transfer, leading to amplified temperature distribution and thickening of the thermal layer.
Molecular identification of the invasive subterranean termite Reticulitermes grassei (Blattodea: Rhinotermitidae) outside its known distribution: introduction routes and implications for pest management strategies
Authors: Hernández-Teixidor David , Duarte Sónia , Taheri Ahmed , Borges Paulo A V , Nunes Lina
Published: April 2024

Despite providing important ecosystem services, termites are also serious pests of wooden structures. Termites are highly adaptive organisms that cause concern as an invasive species. Predictions of the future spread of their distribution range due to factors such as climate change, urban growth, and global trade present new challenges to our capacity to protect our wood and wood-based materials and structures effectively. Reticulitermes grassei Clément, 1978 (Blattodea: Rhinotermitidae) is a subterranean termite native to the Iberian Peninsula and France, whose global distribution has widened over recent years. This article updates the distribution range of this species, confirming its identification in the Azores, Madeira, and Morocco through molecular analysis. The origin and consequences of these putative invasive populations are discussed in light of previously available data. The resulting network showed a highly structured base consisting of many haplotypes from the southern and southwestern Iberian Peninsula (Spain and Portugal), including those from Morocco (in natural landscapes) and Switzerland (in infrastructures). The more derived part of the network includes the haplotypes from southwest France, the northwest Iberian Peninsula, the United Kingdom, Azores, and Madeira, the last 3 being linked probably to human-mediated transportation events. The potential impacts of invasive subterranean termite populations expanding into new regions are concerning, especially in urban environments, and remain uncertain in natural areas. The challenges posed by these termites could be especially worrying in island ecosystems. Hence, it is crucial to implement early warning systems and monitoring programs in regions susceptible to subterranean termite invasions.
Diffraction contrast of ferroelectric domains in DPC STEM images
Authors: Takamoto Masaya , Seki Takehito , Ikuhara Yuichi , Shibata Naoya
Published: April 2024

Differential phase contrast scanning transmission electron microscopy (DPC STEM) is a powerful technique for directly visualizing electromagnetic fields inside materials at high spatial resolution. Electric field observation within ferroelectric materials is potentially possible by DPC STEM, but concomitant diffraction contrast hinders the quantitative electric field evaluation. Diffraction contrast is basically caused by the diffraction-condition variation inside a field of view, but in the case of ferroelectric materials, the diffraction conditions can also change with respect to the polarization orientations. To quantitatively observe electric field distribution inside ferroelectric domains, the formation mechanism of diffraction contrast should be clarified in detail. In this study, we systematically simulated diffraction contrast of ferroelectric domains in DPC STEM images based on the dynamical diffraction theory, and clarify the issues for quantitatively observing electric fields inside ferroelectric domains. Furthermore, we conducted experimental DPC STEM observations for a ferroelectric material to confirm the influence of diffraction contrast predicted by the simulations.
Reflections on arts-based research methods in refugee mental health: The role of creative exercises in nurturing positive coping with trauma and exile
Authors: de Smet Sofie , Spaas Caroline , Jervelund Signe Smith , Skovdal Morten , De Haene Lucia
Published: April 2024

In the field of refugee mental health research, scholars have emphasized the ethical obligation for research practices to benefit participants. They have proposed that research participation itself can promote positive coping in the aftermath of migration. In this article, we aim to advance the understanding of the benefits of arts-based research methods (ABRM) in how they may nurture participants’ positive coping during their experiences as research participants. To do so, we depart from the findings from three drama-based mental health interventions conducted with refugee and migrant young people resettled in Europe on the role creative processes might play in fostering coping. We develop a reflection on how ABRM may tap into these processes to strengthen refugees’ coping and well-being, ultimately supporting ethical research practices. In the final section, we discuss the value of integrating ABRM in refugee mental health research that embeds similar creative processes in their methodological repertoire.
Temporary turn in the asylum regime and the deportable refugee: The case of Syrians in Türkiye
Authors: Tunaboylu Sevda
Published: April 2024

Within the context of forced repatriation, this study investigates the conditions under which Syrian refugees face the spectacle of detention and deportation in Türkiye. As the largest group of Temporary Protection holders within a single country (currently 3.7 million), this case provides a unique lens to examine how asylum policies’ increased emphasis on the temporariness of protection and the eventual return leads to the production of illegality, and consequently of the deportable refugee. Based on qualitative data collected between September and December 2019 in Istanbul, Türkiye, this paper argues that the escalating fear of deportability is built on three pillars: (1) exploitation in the informal labour market, (2) quotidian police surveillance and factory raids, and (3) discrimination in public life. The study contributes to the discussion of temporality and deportability in refugee studies.
Associated factors of vaginal laxity and female sexual function: a cross-sectional study
Authors: Pereira Gláucia Miranda Varella , Brito Luiz Gustavo Oliveira , Ledger Nina , Juliato Cássia Raquel Teatin , Domoney Claudine , Cartwright Rufus
Published: April 2024

Background

Female sexual dysfunction (FSD), including vaginal laxity (VL), can lead to a decrease in quality of life and affect partner relationships.

Aim

We aimed to investigate the associated factors of VL and FSD and their relationship with other pelvic floor disorders in a female population.

Methods

This cross-sectional study was conducted at Chelsea and Westminster Hospital from July to December 2022. All women referred to clinical care at the urogynecology clinic were included. Participants were assessed according to sociodemographic and clinical aspects, the Pelvic Organ Prolapse Quantification system, sexual function, VL, sexual attitudes, sexual distress, sexual quality of life, vaginal symptoms, and pelvic floor disorders. Unadjusted and adjusted associated factors of VL and FSD were analyzed.

Outcomes

The primary outcome was the identification of the associated factors of VL and FSD in a female population, and secondary outcomes included the association between VL and pelvic organ prolapse (POP) with the questionnaire scores.

Results

Among participants (N = 300), vaginal delivery, multiparity, perineal laceration, menopause, and gel hormone were significantly more frequent in those reporting VL (all P < .05). When compared with nulliparity, primiparity and multiparity increased the odds of VL by approximately 4 and 12 times, respectively (unadjusted odds ratio [OR], 4.26 [95% CI, 2.05-8.85]; OR, 12.77 [95% CI, 6.53-24.96]). Menopause and perineal laceration increased the odds of VL by 4 and 6 times (unadjusted OR, 4.65 [95% CI, 2.73-7.93]; OR, 6.13 [95% CI, 3.58-10.49]). In multivariate analysis, menopause, primiparity, multiparity, and POP remained associated with VL.

Clinical Implications

Parity, as an obstetric factor, and menopause and staging of POP, as clinical factors, were associated with VL.

Strengths and Limitations

The investigation of associated factors for VL will contribute to the understanding of its pathophysiology. The study design makes it impossible to carry out causal inference.

Conclusion

Menopause, primiparity, multiparity, and POP were highly associated with VL complaints in multivariate analysis.
Anisotropy ansatz for the axisymmetric Jeans equations
Authors: De Deo Leonardo , Ciotti Luca , Pellegrini Silvia
Published: April 2024

The Jeans equations do not form a closed system, and to solve them a parametrization relating the velocity moments is often adopted. For axisymmetric models, a phenomenological choice (the ‘b-ansatz’) is widely used for the relation between the vertical ($\sigma _z^2$) and radial ($\sigma _R^2$) components of the velocity dispersion tensor, thus breaking their identity present in two-integral systems. However, the way in which the ansatz affects the resulting kinematical fields can be quite complicated, so that the analysis of these fields is usually performed only after numerically computing them. We present here a general procedure to study the properties of the ansatz-dependent fields $\overline{v_{\varphi }^2}$, $\Delta =\overline{v_{\varphi }^2}- \sigma _z^2$ and $\Delta _R= \overline{v_{\varphi }^2}- \sigma _R^2$. Specifically, the effects of the b-ansatz can be determined before solving the Jeans equations once the behaviour over the (R, z)-plane of three easy-to-build ansatz-independent functions is known. The procedure also constrains the ansatz to exclude unphysical results (as a negative $\overline{v_{\varphi }^2}$). The method is illustrated by discussing the cases of three well-known galaxy models: the Miyamoto & Nagai and Satoh discs, and the Binney logarithmic halo, for which the regions and the constraints on the ansatz values can be determined analytically; a two-component (Miyamoto & Nagai plus logarithmic halo) model is also discussed.
The impact of nebular Lyman-Continuum on ionizing photons budget and escape fractions from galaxies
Authors: Simmonds C , Verhamme A , Inoue A K , Katz H , Garel T , De Barros S
Published: April 2024

Several Lyman Continuum (Ly C) emitters have been detected so far, but their observed ionizing spectra sometimes differ from attenuated stellar spectra predicted by stellar population synthesis modelling. This discrepancy may be due to a significant contribution of Ly C nebular emission. We aim to quantify the importance this emission in Ly C leakers: its contribution to the ionizing photons budget, and to measurements of Ly C escape. To estimate the nebular contribution to the Ly C spectra of galaxies, we run photoionization models with Cloudy for a range of Binary Population and Spectral Synthesis templates, varying the column density of the surrounding gas, from density-bounded (NH i = 1016 cm−2) to ionization-bounded (NH i = 1019 cm−2) regimes. In the limits of very optically thin (fesc = 1), or thick configurations (fesc = 0), there is no nebular contribution to the emergent Ly C spectra. This contribution matters only at intermediate Ly C opacities (0 < fesc < 1), where it alters the shape of the Ly C spectrum chromatically, so that escape fractions estimates are highly sensitive to the wavelength range over which they are calculated. We propose a formula to estimate integrated escape fractions using Fλ700/Fλ1100 flux ratios, since this wavelength range is not affected by nebular emission. Regarding simulations, the boost of hydrogen ionizing photons escaping galaxies is inversely proportional to the stellar escape fractions, but since typical simulated escape fractions are low, Ly C photons escape is important. Nebular Ly C is a non-negligible additional source of ionizing photons from galaxies, whose contribution has been overlooked so far in observations and in cosmic reionization simulations.
Proto-neutron star convection and the neutrino-driven wind: implications for the νp-process
Authors: Nevins Brian , Roberts Luke F
Published: April 2024

Recent studies of the neutrino-driven wind from proto-neutron stars have indicated that the wind is likely proton rich for much of its lifetime, and the high flux of neutrinos can induce νp-process nucleosynthesis allowing for the formation of heavy elements. It has also been shown that gravito-acoustic waves, generated by convection within the proto-neutron star, can significantly alter the dynamics and nucleosynthesis in the wind. Therefore, we present a study of the effects of convection-driven waves on the nucleosynthesis in proton-rich neutrino-driven winds, focusing on the νp-process. We find that wave effects can strongly impact νp-process nucleosynthesis even at wave luminosities a factor of 10−5 smaller than the total neutrino luminosity. The momentum flux of the waves accelerates the wind, reducing the net neutrino heating and the persistent neutron abundance created by p($\bar{\nu }_\mathrm{ e},e^+$), which impedes νp-process nucleosynthesis. However, this effect is generally counteracted by the effects of waves on seed nucleus formation, as the acceleration of the wind and the heating that occurs as these waves shock both favour a more α-rich environment with very little heavy seed nucleus formation. Overall, higher wave luminosities correlate (albeit non-monotonically) with heavier element νp-processing, up to A ≈ 200 in some cases. At very high wave luminosities (≳10−3Lν), early shock heating by the waves disrupts α recombination, and drives a suppressed, fast-outflow r-process proceeding up to A ≈ 200. This occurs despite an assumed neutrino spectrum that predicts a proton-rich wind with equilibrium Ye = 0.6.
A Giant Metrewave Radio Telescope survey of radio-loud broad absorption line quasars
Authors: Hayashi Takayuki J , Doi Akihiro , Nagai Hiroshi
Published: April 2024

A substantial fraction of quasars display broad absorption lines (BALs) in their rest-frame ultraviolet spectra. While the origin of BALs is thought to be related to the accretion disc wind, it remains unclear whether the observed ratio of BAL to non-BAL quasars is a result of orientation. We conducted observations of 48 BAL quasars and the same number of non-BAL quasars at 322 MHz using the Giant Metrewave Radio Telescope. Combined with previous flux measurements ranging from MHz to GHz frequencies, we compared continuum radio spectra between the two quasar groups. These data offer insights into low-frequency radio properties that have been difficult to investigate with previous observations only at GHz frequencies. Our results show that 73 ± 13 per cent of the BAL quasars exhibit steep or peaked spectra, a higher proportion than the 44 ± 14 per cent observed in the non-BAL quasars. In contrast, there are no discernible differences between the two quasar groups in the radio luminosity, peak frequency, and spectral index distributions of sources with steep or peaked spectra and sources with flat or inverted spectra. Generally, as the jet axis and line of sight become closer to parallel, quasars exhibit flat or inverted spectra rather than steep or peaked spectra. Therefore, these results suggest that BAL quasars are more frequently observed farther from the jet axis than non-BAL quasars. However, given that a certain proportion of BAL quasars exhibit flat or inverted spectra, more than the simple orientation scenario is required to elucidate the radio properties of BAL quasars.
Strong outflows and inefficient star formation in the reionization-era ultrafaint dwarf galaxy Eridanus ii
Authors: Sandford Nathan R , Weinberg David H , Weisz Daniel R , Fu Sal Wanying
Published: April 2024

We present novel constraints on the underlying galaxy formation physics (e.g. mass-loading factor, star formation history, and metal retention) at z ≳ 7 for the low-mass (M* ∼ 105 M⊙) Local Group ultrafaint dwarf galaxy (UFD) Eridanus ii (Eri ii). Using a hierarchical Bayesian framework, we apply a one-zone chemical evolution model to Eri ii’s CaHK-based photometric metallicity distribution function (MDF; [Fe/H]) and find that the evolution of Eri ii is well characterized by a short, exponentially declining star formation history ($\tau _\text{SFH}=0.39\pm _{0.13}^{0.18}$ Gyr), a low star formation efficiency ($\tau _\text{SFE}=27.56\pm _{12.92}^{25.14}$ Gyr), and a large mass-loading factor ($\eta =194.53\pm _{42.67}^{33.37}$). Our results are consistent with Eri ii forming the majority of its stars before the end of reionization. The large mass-loading factor implies strong outflows in the early history of Eri ii and is in good agreement with theoretical predictions for the mass scaling of galactic winds. It also results in the ejection of >90 per cent of the metals produced in Eri ii. We make predictions for the distribution of [Mg/Fe]–[Fe/H] in Eri ii as well as the prevalence of ultra metal-poor stars, both of which can be tested by future chemical abundance measurements. Spectroscopic follow-up of the highest metallicity stars in Eri ii ([Fe/H] > −2) will greatly improve model constraints. Our new framework can readily be applied to all UFDs throughout the Local Group, providing new insights into the underlying physics governing the evolution of the faintest galaxies in the reionization era.
Planetary Nebula NGC 2818: Revealing its complex 3D morphology
Authors: Derlopa S , Akras S , Amram P , Boumis P , Chiotellis A , de Oliveira C Mendes
Published: April 2024

We carry out an advanced morpho-kinematic analysis of the Planetary Nebula (PN) NGC 2818, whose complex morphology is described by a basic bipolar component, filamentary structures and a knotty central region. We performed an upgrated 3D Morpho-kinematic (MK) model by employing the shape software, combining for the first time in PNe optical 2D spatially resolved echelle spectra and Fabry–Perot data cubes. The best-fitting 3D model of NGC 2818 successfully reconstructs the main morphology, considering one bipolar component, radial filamentary structures, and an equatorial component as the geometrical locus of the group of cometary knots. The model shows that the equatorial component has the lower expansion velocity of the system at 70 ± 20 km s−1. The velocity of the bipolar component is 120 ± 20 km s−1, while all the filamentary structures were found to expand at higher velocities of 180 ± 20 km s−1. Moreover, Fabry–Perot data revealed for the first time a north-eastern filament expanding at a mean velocity of 80 ± 20 km s−1, while its equivalent counterpart in the south-western region was confirmed by a new detected substructure in the echelle data. A new detected knotty structure at velocity −40 ± 20 km s−1 is also reported, as expelled material from the fragmented eastern lobe of the nebula. We interpret the overall structure of NGC 2818 as the result of the evolution of a binary system that underwent the common envelope phase, in conjunction with the ejections of a magnetized jet, misaligned with respect to the symmetry axis of the bipolar/elliptical shell.
The turbulent variability of accretion discs observed at high energies
Authors: Mummery Andrew , Turner Samuel G D
Published: April 2024

We use numerical stochastic-viscosity hydrodynamic simulations and new analytical results from thin disc theory to probe the turbulent variability of accretion flows, as observed at high energies. We show that the act of observing accretion discs in the Wien tail exponentially enhances small-scale temperature variability in the flow, which in a real disc will be driven by magnetohydrodynamic turbulence, to large-amplitude luminosity fluctuations (as predicted analytically). In particular, we demonstrate that discs with more spatially coherent turbulence (as might be expected of thicker discs), and relativistic discs observed at larger inclinations, show significant enhancement in their Wien tail variability. We believe that this is the first analysis of relativistic viewing angle effects on turbulent variability in the literature. Using these results, we argue that tidal disruption events represent particularly interesting systems with which to study accretion flow variability, and may in fact be the best astrophysical probes of small-scale disc turbulence. This is a result of a typical tidal disruption event disc being naturally observed in the Wien tail and likely having a somewhat thicker disc and cleaner X-ray spectrum than other sources. We argue for dedicated X-ray observational campaigns of tidal disruption events, with the aim of studying accretion flow variability.
Role of future SNIa data from Rubin LSST in reinvestigating cosmological models
Authors: Shah Rahul , Mitra Ayan , Mukherjee Purba , Pal Barun , Pal Supratik
Published: April 2024

We study how future Type Ia supernovae (SNIa) standard candles detected by the Vera C. Rubin Observatory (LSST) can constrain some cosmological models. We use a realistic 3-yr SNIa simulated data set generated by the LSST Dark Energy Science Collaboration time domain pipeline, which includes a mix of spectroscopic and photometrically identified candidates. We combine these data with cosmic microwave background (CMB) and baryon acoustic oscillation (BAO) measurements to estimate the dark energy model parameters for two models – the baseline Lambda cold dark matter (ΛCDM) and Chevallier–Polarski–Linder (CPL) dark energy parametrization. We compare them with the current constraints obtained from the joint analysis of the latest real data from the Pantheon SNIa compilation, CMB from Planck 2018 and BAO. Our analysis finds tighter constraints on the model parameters along with a significant reduction of correlation between H0 and σ8,0. We find that LSST is expected to significantly improve upon the existing SNIa data in the critical analysis of cosmological models.
How time weathers galaxies: the temporal impact of the cluster environment on galaxy formation and evolution
Authors: O’Neil Stephanie , Borrow Josh , Vogelsberger Mark , Zhao Hanzhang , Wang Bing
Published: April 2024

We illuminate the altered evolution of galaxies in clusters compared to central galaxies by tracking galaxies in the IllustrisTNG300 simulation as they enter isolated clusters of mass 1013 < M200,mean/M⊙ < 1015 (at z = 0). We demonstrate significant trends in galaxy properties with residence time (time since first infall) and that there is a population of galaxies that remain star forming even many Gyr after their infall. By comparing the properties of galaxies at their infall time to their properties at z = 0, we show how scaling relations, like the stellar-to-halo mass ratio, shift as galaxies live in the cluster environment. Galaxies with a residence time of 10 Gyr increase their stellar-to-halo mass ratio, by around 1 dex. As measurements of the steepest slope of the galaxy cluster number density profile (Rst), frequently used as a proxy for the splashback radius, have been shown to depend strongly on galaxy selection, we show how Rst depends on galaxy residence time. Using galaxies with residence times less than one cluster crossing time (≈5 Gyr) to measure Rst leads to significant offsets relative to using the entire galaxy population. Galaxies must have had the opportunity to ‘splash back’ to the first caustic to trace out a representative value of Rst, potentially leading to issues for galaxy surveys using ultraviolet-selected galaxies. Our work demonstrates that the evolution of cluster galaxies continues well into their lifetime in the cluster and departs from a typical central galaxy evolutionary path.
Scaling and universality in the temporal occurrence of repeating FRBs
Authors: Du Yan-Qi , Wang Ping , Song Li-Ming , Xiong Shao-Lin
Published: April 2024

Fast Radio Bursts (FRBs) are energetic phenomena that have significant implications for understanding fundamental physics and the Universe. Recent observations of FRB 121102, FRB 20220912A, and FRB 20201124A by the Five-hundred-meter Aperture Spherical Telescope showed high-burst rates and distinctive energy distribution and temporal properties. In this study, we examine these observations to investigate the scale invariance of the waiting times between bursts for intervals longer than approximately 1 s. Our analysis revealed a unified scaling law for these longer intervals, which is similar to the behaviour of solar flares. This discovery inspires us to suggest a dual analogy of the FRB scenario across the entire time intervals: with earthquake dynamics at subsecond scales and with solar flare dynamics beyond the one-second threshold. This threshold potentially aligns with the dynamic time-scale of neutron star crusts, offering insight of the occurrence of FRBs into the internal processes of neutron stars.
Quest for a stable Cu-ligand complex with a high catalytic activity to produce reactive oxygen species
Authors: Bouraguba Merwan , Schmitt Adeline M , Yelisetty Venkata Suseela , Vileno Bertrand , Melin Frédéric , Glattard Elise , Orvain Christophe , Lebrun Vincent , Raibaut Laurent , Ilbert Marianne , Bechinger Burkhard , Hellwig Petra , Gaiddon Christian , Sour Angélique , Faller Peter
Published: April 2024

Metal ion–catalyzed overproduction of reactive oxygen species (ROS) is believed to contribute significantly to oxidative stress and be involved in several biological processes, from immune defense to development of diseases. Among the essential metal ions, copper is one of the most efficient catalysts in ROS production in the presence of O2 and a physiological reducing agent such as ascorbate. To control this chemistry, Cu ions are tightly coordinated to biomolecules. Free or loosely bound Cu ions are generally avoided to prevent their toxicity. In the present report, we aim to find stable Cu-ligand complexes (Cu-L) that can efficiently catalyze the production of ROS in the presence of ascorbate under aerobic conditions. Thermodynamic stability would be needed to avoid dissociation in the biological environment, and high ROS catalysis is of interest for applications as antimicrobial or anticancer agents. A series of Cu complexes with the well-known tripodal and tetradentate ligands containing a central amine linked to three pyridyl-alkyl arms of different lengths were investigated. Two of them with mixed arm length showed a higher catalytic activity in the oxidation of ascorbate and subsequent ROS production than Cu salts in buffer, which is an unprecedented result. Despite these high catalytic activities, no increased antimicrobial activity toward Escherichia coli or cytotoxicity against eukaryotic AGS cells in culture related to Cu-L–based ROS production could be observed. The potential reasons for discrepancy between in vitro and in cell data are discussed.
The Effect of Nicotine-Containing Products on Peri-Implant Tissues: A Systematic Review and Network Meta-Analysis
Authors: Vámos Orsolya , Komora Péter , Gede Noémi , Hegyi Péter , Kelemen Kata , Varga Gábor , Mikulás Krisztina , Kerémi Beáta , Kispélyi Barbara
Published: April 2024

Introduction

Smokers have a higher chance of developing peri-implant diseases and are therefore considered an at-risk population. Our aim was to compare peri-implant characteristics in users of electronic cigarettes (EC), waterpipes (WP), cigarettes (CS), smokeless tobacco (ST), and nonsmokers (nonusers of any nicotine and tobacco product; NS).

Aims and Methods

A systematic search of four electronic databases (PubMed, EMBASE, Web of Science, and CENTRAL) was performed until April 2023, restricted to English language. Thirty-nine observational studies were included in the qualitative synthesis, of which 32 studies were included in a Bayesian network meta-analysis. Using a predesigned form, two researchers independently collected data about marginal bone loss (MBL), probing pocket depth (PPD), plaque index, bleeding on probing, modified plaque index, probing pocket depth > 4 mm (PPD > 4), gingival index, peri-implant sulcular fluid volume, and TNF-α and IL-1β levels. QUIPS and CINeMA were used to evaluate the risk of bias and certainty of evidence.

Results

Nonsmokers had the smallest MBL. Most nicotine-containing product users had significantly higher MBL (CS, mean difference [MD]: 1.34 credible interval [CrI]: 0.85, 1.79; WP, MD: 1.58 CrI: 0.84, 2.35; ST, MD: 2.53, CrI: 1.20, 3.87) than NS. Electronic cigarettes did not show significant difference compared to NS (MD: 0.52 CrI: −0.33, 1.36). In secondary outcomes, NS were ranked in first place. Subset analysis based on smoking habit, implant duration, and maintenance control revealed no differences in ranking probability.

Conclusions

Most nicotine-containing product users presented worse peri-implant parameters compared to NS, while EC users did not show significant differences to NS in many outcomes.

Implications

Alternative nicotine-containing products are gaining popularity and are often considered less harmful by the general public compared to traditional cigarettes. This is the first network meta-analysis comparing users of four nicotine-containing products and NS. This study shows that CS, WP, and ST have a detrimental effect on the overall health of peri-implant tissues. EC users also presented inferior parameters compared to NS; however, the difference was not significant in many outcomes. It is essential to educate patients who are using nicotine-containing products, and to provide proper maintenance and appropriate cessation support. Well-designed multiarmed studies are needed for direct comparison of different products, including heated tobacco products. Greater transparency of confounding factors is needed regarding smoking habit and oral hygiene.
European Enslavement of Indigenous People in the Americas
Authors: Goetz Rebecca Anne
Published: April 2024

The immensity and longevity of the European trade in enslaved Indigenous people shaped colonialism in the Americas. Europeans enslaved between two and five million Indigenous people in the Americas between 1492 and 1900. About 650,000 Indigenous people were enslaved in the greater Caribbean before 1542 alone. Indigenous enslavement’s chameleon-like qualities contributed to its ubiquity and its longevity. Europeans developed legally sanctioned trades by capturing, enslaving, and selling Indigenous people. Sometimes Europeans slaved based on their understandings of just wars and of slavery as a punishment for crime. At other times Europeans acquired enslaved people through trade and diplomacy with Indigenous polities. On the edges of empire, far from the reaches of imperial authority, raiding and slaving remained common well into the eighteenth and nineteenth centuries. The diversity of enslavement practices meant that European slaving practices could be adapted to different geographies, different circumstances, and different legal environments. Even when slaving was technically illegal, Europeans used a variety of means to extract forced labor from Indigenous people. In the Caribbean, Central America, and South America, these took the form of the encomienda or repartimiento, both forms of labor tribute and obligation that differed very little from slavery in the daily lives of Indigenous people. In other places Europeans coopted Indigenous forms of labor obligation, such as naboría in the Caribbean, mita in Peru, or yanaconazgo in the lowland Andes. In other places, debt peonage or permanent forms of indentured servitude persisted. European slaving had profound impacts on Indigenous societies. Many Indigenous communities experienced severe political and social disruptions. Some Indigenous communities relied on their own traditions to resist slaving, using diplomacy creatively to resist European encroachment. Others formed multiethnic, coalescent communities to protect themselves. Some Indigenous people also used armed resistance against European slaving and colonialism. A note on terminology: older work will often use the term “Indian slavery” or refer to Indigenous people generically as “Indian.” This use is increasingly out of favor and many Indigenous people consider the term inaccurate or even offensive. Accordingly, more recent scholarship will usually use the terms “Indigenous” or “Native,” and when possible use appropriate ethnonyms to refer to particular communities.