bluuebunny/crossref_metadata_2025 huggingface dataset:
Yielding behavior of concentrated lithium-ion battery anode slurry
Authors: Kim Yeseul , Kim Sunhyung , Kim Byoung Soo , Park Jeong Hoon , Ahn Kyung Hyun , Park Jun Dong
Published: December 2022

The nonlinear rheology of a concentrated lithium-ion battery anode slurry was examined under large amplitude oscillatory shear and interpreted with a sequence of physical process (SPP) analysis. A complex interplay of three anode slurry components—graphite (Gr) as an active material, carbon black (CB) as a conductive additive, and carboxymethyl cellulose (CMC) as a binder—leads to a two-step yielding behavior, represented as the secondary plateau in dynamic strain and stress sweep tests. We demonstrate that a two-step yielding behavior is manifested as double deltoids in SPP analysis through the study of intra-cycle rheological transition under oscillatory shear flow. Slurries of Gr-CMC exhibit the two-step yielding behavior; slurries of CB-CMC do not, suggesting that Gr and CMC are the primary causes of two-step yielding in an anode slurry. A sedimentation test on a dilute Gr-CMC solution yielded phase separation between graphite particles, with CMC adsorbed on their surface and graphite particles aggregated via hydrophobic attraction. This indicates two possible types of interactions in a concentrated slurry: a hydrophobic interaction between graphite particles and a physicochemical interaction caused by CMC adsorbed on graphite particles. The first yielding step relates to the hydrophobic attraction between graphite particles, resulting in a network structure that is expected to be brittle and rupture at a small strain. The second yielding step is attributed to the interaction between concentrated CMC, which is corroborated by the overlap of the secondary deltoid of the anode slurry and the single deltoid of the concentrated CMC solution in SPP analysis.
Flexocaloric effect in superelastic materials
Authors: Pérez-Junyent Clàudia , Porta Marcel , Valdés Emma , Mañosa Lluís , Planes Antoni , Saxena Avadh , Vives Eduard
Published: December 2022

We present a combined theoretical–experimental study of flexocaloric effects in superelastic materials exhibiting structural transitions. We study a Ginzburg–Landau model combined with a vibrational model for a beam near a ferroelastic transition loaded with a three-point bending setup. We also perform experiments on a Cu–Al–Ni single crystal undergoing a martensitic transition. We measure bent beam profiles, vertical force vs vertical deflection during a slow isothermal process, time evolution of the bending and unbending amplitudes, and the evolution of temperature profiles. We also compute the evolution of heat source and heat sink profiles. Finally, we study the location of acoustic emission events during the bending/unbending experiment. Our observations are consistent with the model predictions and allow us to identify the main physical parameters relevant for flexocaloric applications.
Nonlinear interactions of global instabilities in hypersonic laminar flow over a double cone
Authors: Fan Jianhui , Hao Jiaao , Wen Chih-Yung
Published: December 2022

Hypersonic laminar flow over a canonical 25–55° double cone is studied using computational fluid dynamics, bispectrum analysis, and dynamic mode decomposition (DMD) with a freestream Mach number of 11.5 and unit Reynolds number of 1.6×105 m−1. The present study focuses on the evolution and nonlinear behavior of perturbation modes in the flow. The presence of the perturbation modes is first described in detail through the results of direct numerical simulation. The results of high-order spectrum analysis (bispectrum) then reveal complex nonlinear interactions in the flow. By examining the evolution of such interactions, the frequency broadening phenomenon of the fully saturated flow is explained, and the unsteady dynamics of the fully saturated flow are recognized to be caused by the nonlinear saturation of linear instability in the flow. This causality is further confirmed by the DMD results of the Stanton number near the reattachment region. The origins and dynamics of unsteady saturated flow in the hypersonic laminar flow are, therefore, demonstrated.
A polyvalent multiepitope protein cross-protects against
Vibrio cholerae
infection in rabbit colonization and passive protection models
Authors: Upadhyay Ipshita , Li Siqi , Ptacek Galen , Seo Hyesuk , Sack David A. , Zhang Weiping
Published: December 2022

Using epitope- and structure-based multiepitope fusion antigen vaccinology platform, we constructed a polyvalent protein immunogen that presents antigenic domains (epitopes) of
Vibrio cholerae
toxin-coregulated pilus A, cholera toxin (CT), sialidase, hemolysin A, flagellins (B, C, and D), and peptides mimicking lipopolysaccharide O-antigen on a flagellin B backbone. Mice and rabbits immunized intramuscularly with this polyvalent protein immunogen developed antibodies to all of the virulence factors targeted by the immunogen except lipopolysaccharide. Mouse and rabbit antibodies exhibited functional activities against CT enterotoxicity, CT binding to GM
1
ganglioside, bacterial motility, and in vitro adherence of
V. cholerae
O1, O139, and non-O1/non-O139 serogroup strains. When challenged orogastrically with
V. cholerae
O1 El Tor N16961 or a non-O1/non-O139 strain, rabbits IM immunized with the immunogen showed a 2-log (99%) reduction in
V. cholerae
colonization of small intestines. Moreover, infant rabbits born to the mother immunized with the protein immunogen acquired antibodies passively and were protected from bacterial intestinal colonization (>2-log reduction), severe diarrhea (100%), and mild diarrhea (88%) after infection with
V. cholerae
O1 El Tor (N16961), O1 classical (O395), O139 (Bengal), or a non-O1/non-O139 strain. This study demonstrated that this polyvalent cholera protein is broadly immunogenic and cross-protective, and an adult rabbit colonization model and an infant rabbit passive protection model fill a gap in preclinical efficacy assessment in cholera vaccine development.
Catheter-associated urinary tract infection by
Pseudomonas aeruginosa
progresses through acute and chronic phases of infection
Authors: Mekonnen Solomon A. , El Husseini Nour , Turdiev Asan , Carter Jared A. , Belew Ashton Trey , El-Sayed Najib M. , Lee Vincent T.
Published: December 2022

Healthcare-associated infections are major causes of complications that lead to extended hospital stays and significant medical costs. The use of medical devices, including catheters, increases the risk of bacterial colonization and infection through the presence of a foreign surface. Two outcomes are observed for catheterized patients: catheter-associated asymptomatic bacteriuria and catheter-associated urinary tract infection (CAUTI). However, the relationship between these two events remains unclear. To understand this relationship, we studied a murine model of
Pseudomonas aeruginosa
CAUTI. In this model, we also observe two outcomes in infected animals: acute symptoms that is associated with CAUTI and chronic colonization that is associated with asymptomatic bacteriuria. The timing of the acute outcome takes place in the first week of infection, whereas chronic colonization occurs in the second week of infection. We further showed that mutants lacking genes encoding type III secretion system (T3SS), T3SS effector proteins, T3SS injection pore, or T3SS transcriptional activation all fail to cause acute symptoms of CAUTI. Nonetheless, all mutants defective for T3SS colonized the catheter and bladders at levels similar to the parental strain. In contrast, through induction of the T3SS master regulator ExsA, all infected animals showed acute phenotypes with bacteremia. Our results demonstrated that the acute symptoms, which are analogous to CAUTI, and chronic colonization, which is analogous to asymptomatic bacteriuria, are independent events that require distinct bacterial virulence factors. Experimental delineation of asymptomatic bacteriuria and CAUTI informs different strategies for the treatment and intervention of device-associated infections.
Multiscale landscaping of droplet wettability on fibrous layers of facial masks
Authors: Park Sang Jin , Lee Cho Hee , Kim Yeonji , Ko Jun Hyuk , Kim Taewoo , Kim Seong Jin , Nahm Sahn , Cho Hyesung , Moon Myoung-Woon
Published: December 2022

Liquid mobility is ubiquitous in nature, with droplets emerging at all size scales, and artificial surfaces have been designed to mimic such mobility over the past few decades. Meanwhile, millimeter-sized droplets are frequently used for wettability characterization, even with facial mask applications, although these applications have a droplet-size target range that spans from millimeters to aerosols measuring less than a few micrometers. Unlike large droplets, microdroplets can interact sensitively with the fibers they contact with and are prone to evaporation. However, wetting behaviors at the single-microfiber level remain poorly understood. Herein, we characterized the wettability of fibrous layers, which revealed that a multiscale landscape of droplets ranged from the millimeter to the micrometer scale. The contact angle (CA) values of small droplets on pristine fibrous media showed sudden decrements, especially on a single microfiber, owing to the lack of air cushions for the tiny droplets. Moreover, droplets easily adhered to the pristine layer during droplet impact tests and then yielding widespread areas of contamination on the microfibers. To resolve this, we carved nanowalls on the pristine fibers by plasma etching, which effectively suppressed such wetting phenomena. Significantly, the resulting topographies of the microfibers managed the dynamic wettability of droplets at the multiscale, which reduced the probability of contamination with impact droplets and suppressed the wetting transition upon evaporation. These findings for the dynamic wettability of fibrous media will be useful in the fight against infectious droplets.
FtsEX-independent control of RipA-mediated cell separation in
Corynebacteriales
Authors: Gaday Quentin , Megrian Daniela , Carloni Giacomo , Martinez Mariano , Sokolova Bohdana , Ben Assaya Mathilde , Legrand Pierre , Brûlé Sebastien , Haouz Ahmed , Wehenkel Anne Marie , Alzari Pedro M.
Published: December 2022

The bacterial cell wall is a multi-layered mesh, whose major component is peptidoglycan (PG), a sugar polymer cross-linked by short peptide stems. During cell division, a careful balance of PG synthesis and degradation, precisely coordinated both in time and space, is necessary to prevent uncontrolled destruction of the cell wall. In
Corynebacteriales,
the D,L endopeptidase RipA has emerged as a major PG hydrolase for cell separation, and RipA defaults have major implications for virulence of the human pathogens
Mycobacterium tuberculosis
and
Corynebacterium diphtheriae
. However, the precise mechanisms by which RipA mediates cell separation remain elusive. Here we report phylogenetic, biochemical, and structural analysis of the
Corynebacterium glutamicum
homologue of RipA, Cg1735. The crystal structures of full-length Cg1735 in two different crystal forms revealed the C-terminal NlpC/P60 catalytic domain obtruded by its N-terminal conserved coiled-coil domain, which locks the enzyme in an autoinhibited state. We show that this autoinhibition is relieved by the extracellular core domain of the transmembrane septal protein Cg1604. The crystal structure of Cg1604 revealed a (β/α) protein with an overall topology similar to that of receiver domains from response regulator proteins. The atomic model of the Cg1735–Cg1604 complex, based on bioinformatical and mutational analysis, indicates that a conserved, distal-membrane helical insertion in Cg1604 is responsible for Cg1735 activation. The reported data provide important insights into how intracellular cell division signal(s), yet to be identified, control PG hydrolysis during RipA-mediated cell separation in
Corynebacteriales
.
A structural mechanism of nuclear receptor biased agonism
Authors: Nemetchek Michelle D. , Chrisman Ian M. , Rayl Mariah L. , Voss Andrew H. , Hughes Travis S.
Published: December 2022

Efforts to decrease the adverse effects of nuclear receptor (NR) drugs have yielded experimental agonists that produce better outcomes in mice. Some of these agonists have been shown to cause different, not just less intense, on-target transcriptomic effects; however, a structural explanation for such agonist-specific effects remains unknown. Here, we show that partial agonists of the NR peroxisome proliferator-associated receptor γ (PPARγ), which induce better outcomes in mice compared to clinically utilized type II diabetes PPARγ-binding drugs thiazolidinediones (TZDs), also favor a different group of coactivator peptides than the TZDs. We find that PPARγ full agonists can also be biased relative to each other in terms of coactivator peptide binding. We find differences in coactivator–PPARγ bonding between the coactivator subgroups which allow agonists to favor one group of coactivator peptides over another, including differential bonding to a C-terminal residue of helix 4. Analysis of all available NR–coactivator structures indicates that such differential helix 4 bonding persists across other NR–coactivator complexes, providing a general structural mechanism of biased agonism for many NRs. Further work will be necessary to determine if such bias translates into altered coactivator occupancy and physiology in cells.
Anaphore et marqueurs du discours
Authors: Saiz-Sánchez Marta
Published: December 2022

Les marqueurs d’accord et de désaccordoui,nonetsiont été décrits traditionnellement en termes d’anaphore ou de mot-phrase puisque leur interprétation sémantique dépend du contexte antérieur. Toutefois, dans l’interaction spontanée, ces marqueurs ne sont pas toujours les équivalents d’un segment de discours antérieur. Parfois ils renvoient à l’énonciation, à un contenu sémantique inféré, voire à une situation extralinguistique. Après avoir présenté plusieurs travaux sur différents types d’anaphores, nous proposons le concept d’anaphore situationnellepour décrire le fonctionnement référentiel deoui,nonetsi. Ces marqueurs reprennent un schéma situationnel avec des variables qui s’actualisent avec la situation énonciative. Cette proposition permet d’unifier la description anaphorique des trois marqueurs dans tous les cas de figure.
Elsinoë australis Bitancourt & Jenkins. [Distribution map].
Authors: CABI  , EPPO
Published: December 2022

A new distribution map is provided for Elsinoë australis Bitancourt & Jenkins. Dothideomycetes: Myriangiales: Elsinoaceae. Hosts: Citrus spp. especially navel orange (
C. sinensis
) and mandarin (
C. reticulata
); poplar (
Populus tomentosa
and
P. deltoides
).
Candidatus Liberibacter africanus Jagoueix, Bové & Garnier. [Distribution map].
Authors: CABI  , EPPO
Published: December 2022

A new distribution map is provided for Candidatus Liberibacter africanus Jagoueix, Bové & Garnier. Alphaproteobacteria: Rhizobiales: Phyllobacteriaceae. Hosts:
Citrus
spp.
Phytophthora ramorum Werres, de Cock & Manin 't Veld. [Distribution map].
Authors: CABI  , EPPO
Published: December 2022

A new distribution map is provided for Phytophthora ramorum Werres, de Cock & Manin 't Veld. Oomycetes: Peronosporales: Peronosporaceae. Hosts: wide host range including many ornamental and tree species, especially oak (
Quercus
sp.), tanoak (
Notholithocarpus densiflorus
), Rhododendron, Pieris, Viburnum and Japanese larch (
Larix kaempferi
).
Deep neural network automated segmentation of cellular structures in volume electron microscopy
Authors: Gallusser Benjamin , Maltese Giorgio , Di Caprio Giuseppe , Vadakkan Tegy John , Sanyal Anwesha , Somerville Elliott , Sahasrabudhe Mihir , O’Connor Justin , Weigert Martin , Kirchhausen Tom
Published: December 2022

Volume electron microscopy is an important imaging modality in contemporary cell biology. Identification of intracellular structures is a laborious process limiting the effective use of this potentially powerful tool. We resolved this bottleneck with automated segmentation of intracellular substructures in electron microscopy (ASEM), a new pipeline to train a convolutional neural network to detect structures of a wide range in size and complexity. We obtained dedicated models for each structure based on a small number of sparsely annotated ground truth images from only one or two cells. Model generalization was improved with a rapid, computationally effective strategy to refine a trained model by including a few additional annotations. We identified mitochondria, Golgi apparatus, endoplasmic reticulum, nuclear pore complexes, caveolae, clathrin-coated pits, and vesicles imaged by focused ion beam scanning electron microscopy. We uncovered a wide range of membrane–nuclear pore diameters within a single cell and derived morphological metrics from clathrin-coated pits and vesicles, consistent with the classical constant-growth assembly model.
Micro-gas sensor with a suspended micro-heater for ammonia gas detection
Authors: Hsieh Chia-Hsu , Lin Tsung-Wei , Juang Feng-Renn , Huang I-Yu
Published: December 2022

In this research, the ammonia micro-gas sensor is developed by micro-electromechanical systems (MEMS) technology. A suspended micro-heater is also integrated on the same chip to provide the optimal operating temperature during sensing. The main processing steps of the implemented micro-sensor in this study involve five photolithographic and seven thin-film deposition processes. In addition, in order to reduce the heat loss of the heater, this study uses anisotropic wet etching of MEMS technology to create a suspension structure that can reduce the heat conduction of silicon. Finally, tungsten trioxide is used as a sensing film to measure the variation of resistance. The chip size of the proposed micro ammonia sensor developed in this paper is 5 mm × 5 mm. At the concentration of 5 ppm ammonia, the sensing response can reach 252%, and the response time is 30 s. The lowest detection limit reaches 40 ppb. In summary, the micro-ammonia gas sensor with a micro-heater developed in this paper has the advantages of high response value, low detection limit and small size.
Study of electromagnetic interference shielding effectiveness of multilayer graphene films by Monte Carlo method
Authors: Fang Chao , Chen Xiqu , Zhang Juanjuan , Xia Xiaodong , Weng George J
Published: December 2022

In this paper, the electromagnetic interference shielding effectiveness (EMI SE) of multilayer graphene films is studied by the Monte Carlo (MC) method. First, we use the transfer matrix method to study the transmission and reflection of electric fields of the incident light passing through the graphene plane and the dielectric interface, and then determine the reflection and transmission probability of the light. In this way, the path of light can be obtained by the MC method. From the distance and emission direction of a large number of lights passing through the film, the expected value of the emitted light field is calculated and the EMI SE is determined. The obtained results of SE are shown to be in good agreement with several sets of experimental data. This model also takes into account the influence of wrinkles of graphene. It is found that EMI SE first increases and then decreases with the increase of wrinkle. The effects of film thickness, conductivity, and dielectric constant on EMI SE in the X-band frequency range are also investigated.
Effects of Combining Occupationally Relevant Physical and Cognitive Tasks. A Systematic Review
Authors: Mixter Susanna , Mathiassen Svend Erik , Jahncke Helena , Hygge Staffan , Lyskov Eugene , Hallman David M , Lewis Charlotte
Published: December 2022

Objectives

Physical and cognitive tasks occur together in many occupations. Previous reviews of combined tasks have mainly focused on their effects in a sports context. This review investigated to which extent combinations (concurrent or alternating) of occupationally relevant physical and cognitive tasks influence responses reflecting biomechanical exposure, stress, fatigue, performance, and well-being.

Methods

We searched Scopus, Pubmed, Cinahl, and Psychinfo for controlled experiments investigating the effects of combinations of occupationally relevant physical and cognitive tasks in participants aged 18 to 70. In total, we identified 12 447 records. We added recent papers that had cited these studies (n = 573) to arrive at a total of 13 020 publications. After screening for relevance, 61 studies remained, of which 57 were classified to be of medium or high quality. Of the 57 studies, 51 addressed concurrent tasks, 5 alternating tasks, and 1 both concurrent and alternating tasks.

Results

Most studies of concurrent physical and cognitive tasks reported negative effects, if numerically small, on indicators of biomechanical exposure, fatigue, and performance, compared to a physical task alone. Results were mixed for stress indicators, and well-being was too little studied to justify any conclusions. Effects depended on the tasks, including their intensity and complexity. Alternating physical and cognitive tasks did not appear to influence outcomes much, compared to having passive breaks in-between physical tasks.

Conclusions

The reviewed evidence indicated that concurrent physical and cognitive work tasks have negative, yet small effects on biomechanical indicators, fatigue and performance, compared to performing the physical task alone, but only if the physical task is intense, and the cognitive task is complex. Alternating between physical and cognitive tasks may have similar effects as breaking up physical tasks by passive breaks, but studies were few. Future studies should address ecologically valid combinations of physical and cognitive tasks, in particular in controlled field studies devoted to the long-term effects of combined work.
Spatiotemporal behavior of predators and prey in an arid environment of Central Asia
Authors: Franchini Marcello , Atzeni Luciano , Lovari Sandro , Nasanbat Battogtokh , Ravchig Samiya , Herrador Francisco Ceacero , Bombieri Giovanni , Augugliaro Claudio
Published: December 2022

The mechanisms of interactions between apex and smaller carnivores may range from competition to facilitation. Conversely, interactions between predators and prey are mainly driven by the prey reducing the likelihood of encounters with predators. In this study, we investigated (1) the spatiotemporal interactions between an apex (the snow leopard) and a meso-predator (the red fox), and (2) the temporal interactions between the snow leopard and its potential prey (Siberian ibex, argali, Asian wild ass, Tolai hare) through camera trapping in the Mongolian Great Gobi-A. The probability of occurrence for the red fox was higher in the presence of the snow leopard than in its absence. Moreover, the red fox activity pattern matched that of the snow leopard, with both species mostly active at sunset. This positive spatiotemporal interaction suggests that the presence of the snow leopard may be beneficial for the red fox in terms of scavenging opportunities. However, other explanations may also be possible. Amongst prey, the Siberian ibex and the argali were mainly active during the day, whereas the Asian wild ass and the Tolai hare were more nocturnal. These findings suggest that potential prey (especially the Siberian ibex and the argali) may shape their behavior to decrease the opportunity for encounters with the snow leopard. Our results have revealed complex interactions between apex and smaller predators and between apex predator and its potential prey.
Mal de Debarquement Syndrome explained by a vestibulo–cerebellar oscillator
Authors: Burlando Bruno , Mucci Viviana , Browne Cherylea J , Losacco Serena , Indovina Iole , Marinelli Lucio , Blanchini Franco , Giordano Giulia
Published: December 2022

Mal de Debarquement Syndrome (MdDS) is a puzzling central vestibular disorder characterized by a long-lasting perception of oscillatory postural instability that may occur after sea travels or flights. We have postulated that MdDS originates from the post-disembarking persistence of an adaptive internal oscillator consisting of a loop system, involving the right and left vestibular nuclei, and the Purkinje cells of the right and left flocculonodular cerebellar cortex, connected by GABAergic and glutamatergic fibers. We have formulated here a mathematical model of the vestibulo–cerebellar loop system and carried out a computational analysis based on a set of differential equations describing the interactions among the loop elements and containing Hill functions that model input–output firing rates relationships among neurons. The analysis indicates that the system acquires a spontaneous and permanent oscillatory behavior for a decrease of threshold and an increase of sensitivity in neuronal input–output responses. These results suggest a role for synaptic plasticity in MdDS pathophysiology, thus reinforcing our previous hypothesis that MdDS may be the result of excessive synaptic plasticity acting on the vestibulo–cerebellar network during its entraining to an oscillatory environment. Hence, our study points to neuroendocrine pathways that lead to increased synaptic response as possible new therapeutic targets for the clinical treatment of the disorder.
Modelling of the post-asymptotic giant branch phase as a tool to understand asymptotic giant branch evolution and nucleosynthesis
Authors: Kamath D , Dell’Agli F , Ventura P , Van Winckel H , Tosi S , Karakas A I
Published: December 2022

We study a sample of single Galactic post-asymptotic giant branch (post-AGB) stars with known surface chemical composition. Gaia  EDR3 and Gaia  DR3 parallaxes have enabled accurate determinations of the luminosities of these objects, thus making it possible to characterize them in terms of their initial masses, chemical compositions, and progenitor ages. We used extant evolutionary sequences of asymptotic giant branch (AGB) stars produced using the ATON stellar evolutionary code extended to the post-AGB phase, specifically for this study. The luminosity and surface carbon abundance together prove to be the most valuable indicator of the previous evolution and nucleosynthetic history of the star, particularly regarding the efficiency of mixing mechanisms and the growth of the core. This analysis allows us to place the post-AGB sample into classes based on their evolutionary history on the AGB. This includes low-mass objects that evolved as M-type stars without third dredge-up, carbon stars, and intermediate-mass AGB stars with hot bottom burning (HBB). Additionally, our analysis reveals that AGB nucleosynthesis is not homogeneous, even for stars with similar initial masses and metallicities. The approach of using observations of post-AGB stars to constrain AGB and post-AGB models shed new light on still debated issues related to the AGB evolution, such as the threshold mass required to become a C-star, the minimum mass for HBB and the amount of carbon that can be accumulated in the surface regions of the star during the AGB lifetime, as well as deep mixing experienced during the red giant branch phase.
On the ages of bright galaxies ∼500 Myr after the big bang: insights into star formation activity at z ≳ 15 with JWST
Authors: Whitler Lily , Endsley Ryan , Stark Daniel P , Topping Michael , Chen Zuyi , Charlot Stéphane
Published: December 2022

With JWST, new opportunities to study the evolution of galaxies in the early Universe are emerging. Spitzer constraints on rest-optical properties of z ≳ 7 galaxies demonstrated the power of using galaxy stellar masses and star formation histories (SFHs) to indirectly infer the cosmic star formation history. However, only the brightest individual z ≳ 8 objects could be detected with Spitzer, making it difficult to robustly constrain activity at z ≳ 10. Here, we leverage the greatly improved rest-optical sensitivity of JWST at z ≳ 8 to constrain the ages of seven UV-bright ($M_{\rm uv}\lesssim -19.5$) galaxies selected to lie at z ∼ 8.5–11, then investigate implications for z ≳ 15 star formation. We infer the properties of individual objects with two spectral energy distribution modelling codes, then infer a distribution of ages for bright z ∼ 8.5–11 galaxies. We find a median age of ∼20 Myr, younger than that inferred at z ∼ 7 with a similar analysis, consistent with an evolution towards larger specific star formation rates at early times. The age distribution suggests that only ∼3 per cent of bright z ∼ 8.5–11 galaxies would be similarly luminous at z ≳ 15, implying that the number density of bright galaxies declines by at least an order of magnitude between z ∼ 8.5–11 and $z \sim 15$. This evolution is challenging to reconcile with some early JWST results suggesting the abundance of bright galaxies does not significantly decrease towards very early times, but we suggest this tension may be eased if young stellar populations form on top of older stellar components, or if bright z ∼ 15 galaxies are observed during a burst of star formation.
Isolating the extreme debris disc signature – explorations of eccentric extreme debris discs formed by giant impacts
Authors: Lewis Thomas , Watt Lewis , Leinhardt Zoë M
Published: December 2022

In this work, we used N-body simulations and a radiative transfer package to model the evolution of eccentric debris discs produced by giant impacts between planetary embryos. This included how the morphology and infrared emission of these discs varied with embryo eccentricity and collision true anomaly. We found that eccentric discs inherit the eccentric properties of the centre of mass orbit of the two colliding embryos. However, the orientation of the collision with the respect to this orbit plays a key role in determining how closely the disc material resembles the centre of mass orbit. Additionally, we found that increased eccentricity acted to suppress the formation of certain short-term variations in the disc emission depending on the collision position. These short-term variations have been associated with an observational phenomenon called extreme debris discs. Short-term variability has been suggested as a potential signature for giant impacts.
Precession of magnetars: dynamical evolutions and modulations on polarized electromagnetic waves
Authors: Gao Yong , Shao Lijing , Desvignes Gregory , Jones David Ian , Kramer Michael , Yim Garvin
Published: December 2022

Magnetars are conjectured to be highly magnetized neutron stars (NSs). Strong internal magnetic field and elasticity in the crust may deform the stars and lead to free precession. We study the precession dynamics of triaxially deformed NSs incorporating the near-field and the far-field electromagnetic torques. We obtain timing residuals for different NS geometries and torques. We also investigate the polarized X-ray and radio signals from precessing magnetars. The modulations on the Stokes parameters are obtained for thermal X-rays emitted from the surface of magnetars. For radio signals, we apply the simple rotating vector model (RVM) to give the modulations on the position angle (PA) of the polarization. Our results are comprehensive, ready to be used to search for magnetar precession with timing data and polarizations of X-ray and radio emissions. Future observations of precessing magnetars will give us valuable information on the geometry and the strength of the strong magnetic fields, the emission geometry, as well as the equation of state of NSs.
Where are the extremely metal-poor stars in the Milky Way and Andromeda? Expectations from TNG50
Authors: Chen Li-Hsin , Pillepich Annalisa , Glover Simon C O , Klessen Ralf S
Published: December 2022

We analyse the location of extremely metal-poor stars (EMPs; [Fe/H] < −3) in 198 Milky Way (MW)/M31-like galaxies at z = 0 in the TNG50 simulation. Each system is divided into four kinematically defined morphological stellar components based on stellar circularity and galactocentric distance, namely bulge, cold disc, warm disc, and stellar halo, in addition to satellites (with stellar mass $\ge 5\times 10^6\, {\rm M}_\odot$). According to TNG50 and across all simulated systems, the stellar halo of the main galaxy and satellites present the highest frequency of EMPs (largest MEMP, comp-to-Mtot, comp stellar mass ratio), and thus the highest chances of finding them. Such frequency is larger in lower-mass than high-mass satellites. Moreover, TNG50 predicts that the stellar halo of the main galaxy always hosts and thus contributes the majority of the EMPs of the system. Namely, it has the highest mass ratio of EMPs in it to all the EMPs in the system (largest MEMP, comp-to-MEMP(< 300kpc)). However, notably, we also find that 33 MW/M31-like galaxies in TNG50 have cold discs that contribute more than 10 per cent to the total EMP mass, each with $\gtrsim 10^{6.5-7}\, {\rm M}_\odot$ of EMPs in cold circular orbits. These qualitative statements do not depend on the precise definition of EMP stars, i.e. on the adopted metallicity threshold. The results of this work provide a theoretical prediction for the location of EMP stars from both a spatial and kinematic perspective and across an unprecedented number of well-resolved MW/M31-like systems.
Dissipative magnetic structures and scales in small-scale dynamos
Authors: Brandenburg Axel , Rogachevskii Igor , Schober Jennifer
Published: December 2022

Small-scale dynamos play important roles in modern astrophysics, especially on galactic and extragalactic scales. Owing to dynamo action, purely hydrodynamic Kolmogorov turbulence hardly exists and is often replaced by hydromagnetic turbulence. Understanding the size of dissipative magnetic structures is important in estimating the time-scale of galactic scintillation and other observational and theoretical aspects of interstellar and intergalactic small-scale dynamos. Here we show that, during the kinematic phase of the small-scale dynamo, the cutoff wavenumber of the magnetic energy spectra scales as expected for large magnetic Prandtl numbers, but continues in the same way also for moderately small values – contrary to what is expected. For a critical magnetic Prandtl number of about 0.3, the dissipative and resistive cutoffs are found to occur at the same wavenumber. In the non-linearly saturated regime, the critical magnetic Prandtl number becomes unity. The cutoff scale now has a shallower scaling with magnetic Prandtl number below a value of about three, and a steeper one otherwise compared to the kinematic regime.
Repeat Detector: versatile sizing of expanded tandem repeats and identification of interrupted alleles from targeted DNA sequencing
Authors: Taylor Alysha S , Barros Dinis , Gobet Nastassia , Schuepbach Thierry , McAllister Branduff , Aeschbach Lorene , Randall Emma L , Trofimenko Evgeniya , Heuchan Eleanor R , Barszcz Paula , Ciosi Marc , Morgan Joanne , Hafford-Tear Nathaniel J , Davidson Alice E , Massey Thomas H , Monckton Darren G , Jones Lesley , network REGISTRY Investigators of the European Huntington’s disease , Xenarios Ioannis , Dion Vincent
Published: December 2022

Targeted DNA sequencing approaches will improve how the size of short tandem repeats is measured for diagnostic tests and preclinical studies. The expansion of these sequences causes dozens of disorders, with longer tracts generally leading to a more severe disease. Interrupted alleles are sometimes present within repeats and can alter disease manifestation. Determining repeat size mosaicism and identifying interruptions in targeted sequencing datasets remains a major challenge. This is in part because standard alignment tools are ill-suited for repetitive and unstable sequences. To address this, we have developed Repeat Detector (RD), a deterministic profile weighting algorithm for counting repeats in targeted sequencing data. We tested RD using blood-derived DNA samples from Huntington’s disease and Fuchs endothelial corneal dystrophy patients sequenced using either Illumina MiSeq or Pacific Biosciences single-molecule, real-time sequencing platforms. RD was highly accurate in determining repeat sizes of 609 blood-derived samples from Huntington’s disease individuals and did not require prior knowledge of the flanking sequences. Furthermore, RD can be used to identify alleles with interruptions and provide a measure of repeat instability within an individual. RD is therefore highly versatile and may find applications in the diagnosis of expanded repeat disorders and in the development of novel therapies.
Relationship Between a State-Directed Lockdown on Non-COVID-19–related ICU Admissions and Mortality in a Multicenter Colorado Healthcare System
Authors: Park Bryan D. , Kannappan Arun , Rizzo Alicia N. , Jin Ying , Peterson Ryan A. , Burnham Ellen , Moss Marc , Jolley Sarah
Published: December 2022

OBJECTIVES:

Colorado issued a month long statewide lockdown on March 26, 2020, during the initial surge of the COVID-19 pandemic. The impact of this mandate on non–COVID-19 ICU admission rates and outcomes is unclear.

DESIGN:

We performed a retrospective analysis of all medical ICU admissions in the University of Colorado Health System in four predefined periods: 1) prepandemic (2 mo prior to lockdown period 1); 2) mandated lockdown from March 26 to April 26, 2020 (period 2); 3) between surges (period 3); and 4) nonmandated lockdown surge (between November 1, 2020, and March 31, 2021, period 4).

SETTING:

Nonsurgical ICU admissions at the University of Colorado Health Systems, including 10 hospitals throughout Colorado.

SUBJECTS:

All ICU admissions in four predefined time periods.

MEASUREMENTS AND MAIN RESULTS:

We included 13,787 patients who were admitted during the four study periods. The 28-day mortality rates for non–COVID-19 ICU admissions following index ICU admission were 13.6%, 18.0%, 13.5%, and 16.0% across periods 1–4, respectively. However, the increased odds in non–COVID-19 ICU mortality during the mandated lockdown period relative to prepandemic 1 (odds ratio [OR], 1.39; 95% CI, 1.11–1.72; p = 0.0.04) was attenuated and nonsignificant after adjustment for demographics, comorbidities, diagnosis flags, and severity (OR, 1.15; 95% CI, 0.89–1.48; p = 0.27). Similar results were found in time-to-event analyses. The most common diagnosis in each time period was acute respiratory failure (ARF), and we found it to have increased during lockdown (p < 0.001), whereas sepsis admissions increased during and decreased after lockdown (p = 0.004). Admissions for alcohol withdrawal syndrome (AWS) increased during lockdown and 6 months afterwards (p = 0.005).

CONCLUSIONS:

For non-COVID-19–related ICU admissions, mortality rate was similar before, during, and after Colorado’s month long lockdown after confounder adjustment, including typical ICU admission flags. Primary admission diagnoses shifted throughout the predefined study periods with more admissions for severe critical diagnoses (i.e., ARF, sepsis, AWS) occurring during the mandated lockdown and nonmandated lockdown periods compared with the prepandemic and between surge period. This would suggest that the perceived increase in mortality during the lockdown for non–COVID-19 ICU admissions may be related to a shift inpatient demographics.
Early Hyperchloremia and Outcomes After Severe Traumatic Brain Injury: Analysis of Resuscitation Outcomes Consortium Hypertonic Saline Trial
Authors: Qureshi Adnan I. , Ma Xiaoyu , Huang Wei , Nunna Ravi S. , Gomez Francisco , Malhotra Kunal , Arora Niraj , Chandrasekaran Premkumar N. , Siddiq Farhan , Gomez Camilo R. , Suarez Jose I.
Published: December 2022

BACKGROUND/OBJECTIVES:

To investigate the effect of the occurrence of early hyperchloremia on death or severe disability at 180 days in patients with severe traumatic brain injury (TBI).

DESIGN:

Post hoc analysis of Resuscitation Outcomes Consortium Hypertonic Saline (ROC HS)-TBI trial.

SETTING:

A total of 114 North American emergency medical services agencies in the ROC.

PATIENTS:

A total of 991 patients with severe TBI and Glasgow Coma Scale score of less than or equal to 8.

INTERVENTIONS:

Prehospital resuscitation with single IV dose (250 cc) of 7.5% saline in 6% dextran-70, 7.5% saline (no dextran), or crystalloid.

MEASUREMENTS AND MAIN RESULTS:

Patients with increased serum chloride concentrations (110 mmol/L or greater) 24 hours after randomization were identified. Hyperchloremia was graded into one or greater than or equal to 2 occurrences in the first 24 hours. Logistic regression analyses were performed to determine the effects of hyperchloremia on: 1) death or severe disability at 180 days and 2) death within 180 days after adjusting for confounders. Compared with patients without hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death or severe disability at 180 days (odds ratio [OR], 1.81; 95% CI, 1.19–2.75) and death within 180 days (OR, 1.89; 95% CI, 1.14–3.08) after adjustment for confounders. However, the total volume of fluids administered during the first 24 hours was an independent predictor of death within 180 days; therefore, after adding an interaction term between the total volume of fluids administered during the first 24 hours and greater than or equal to 2 occurrences of hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death within 180 days (OR, 2.35; 95% CI, 1.21–4.61 d) but not of composite outcome of death or severe disability at 180 days.

CONCLUSIONS:

After modifying for the effect of the total volume of fluids administered during the first 24 hours, multiple occurrences of hyperchloremia in the first 24 hours were associated with higher odds of death within 180 days in patients with severe TBI.
Piloting Group-Based Behavioral Activation Therapy for Families of Deceased COVID-19 Patients
Authors: England Ashley Eaton , Lietzau Stephanie , Vu James , Hebert Charles , Banayan David , Greenberg Jared A. , Gerhart James
Published: December 2022

BACKGROUND:

Surrogate decision-making is a stressful process for many family members of critically ill patients. The COVID-19 pandemic may have amplified the risk for anxiety, depression, and posttraumatic stress disorder (PTSD) symptoms in ICU surrogates.

OBJECTIVES:

This study piloted an online group-based behavioral intervention with family members of deceased COVID-19 patients. Participant engagement, perceptions, and responses related to the intervention were assessed.

DESIGN:

A single-arm pilot study was conducted with bereaved families. Quantitative analysis of measures of anxiety, depression, and PTSD symptoms was conducted with mixed models. Qualitative data were analyzed to identify themes in surrogates’ experiences with the intervention.

SETTING:

Participants were recruited from ICUs at a tertiary academic medical center. Participants completed the intervention, measures, and interviews online.

SUBJECTS:

Participants were family members of patients who died from COVID-19.

INTERVENTIONS:

The intervention involved six online group-based behavioral activation sessions. Sessions covered topics pertinent to grieving and engagement in personally meaningful activities.

MEASUREMENTS AND MAIN RESULTS:

Semi-structured interviews explored participants’ experiences with the intervention. Surrogates also completed measures of anxiety, depression, and PTSD symptoms before and after the intervention. Nineteen of 26 participants (73.1%) completed the study. Thematic analysis suggested that surrogates found the group helpful for overcoming perceived isolation, receiving validation, and developing coping skills. Significant pre-to-post reductions were observed in symptoms of Hospital and Anxiety Disorder Scale (HADS) anxiety (pre-mean = 9.27, sd = 5.30 vs post-mean = 6.80, sd = 4.16; p = 0.0271), HADS depression (pre-mean =6 .65, sd = 4.58 vs post- mean = 4.89, sd = 3.40; p = 0.0436), and Impact of Events Scale-Revised PTSD (pre-mean = 36.86, sd = 16.97 vs post-mean = 24.14, sd = 13.49; p = 0.0008).

LIMITATIONS:

This was a preliminary study based on qualitative and self-report measures. Future studies should include a control group.

CONCLUSIONS:

Online group-based behavioral activation therapy appears to be a potentially useful intervention for family members of ICU patients who died from COVID-19.
COVID-19 Caregiving Strategies, Quality of Life, and Stress Among Faith Community Nurses and Faith Leaders in Appalachia
Authors: Smothers Angel , Morrissey Elizabeth , Melnick Helen , Beaver Molly , Wang Kesheng , Piamjariyakul Ubolrat
Published: December 2022

Faith community nurses (FCNs), pastors, and priests faced many challenges from the COVID-19 pandemic, serving as frontline sources of support for congregants. The aim of this study was to identify the most common care strategies used during the COVID-19 pandemic and examine professional quality of life, perceived stress, and associated factors in faith leaders and FCNs in rural Appalachia. Using a cross-sectional, descriptive survey design, high compassion satisfaction was reported along with compassion fatigue as caregiving moved to virtual platforms, suggesting the need for greater support.
A Faith-Based Intervention to Address Social Isolation and Loneliness in Older Adults
Authors: Blevins Don'L
Published: December 2022

The goal of this quality improvement project was to determine if virtually offered faith-based resources for socially isolated older adults could reduce loneliness and improve quality of life. A nurse-developed program of virtual spiritual and religious interventions, including mindfulness, prayer, Scripture meditation, gratitude practices, and online church services, was offered by local ministers to older adults at risk of social isolation or loneliness. A sample of 16 adults over age 55 from local communities participated in the 12-week intervention and follow-up. The intervention resulted in a significant decrease in perception of social loneliness and improved physical health quality of life.
The important primary care role of neonatal nurse practitioners in the neonatal intensive care unit
Authors: Etten Kristen , Hoffman Jacqui , Wallman Carol , Bellflower Bobby
Published: December 2022

Neonatal nurse practitioners (NNPs) are recognized as acute care providers but are actually both acute and primary care providers via education and practice. Neonatal nurse practitioners provide primary care such as anticipatory guidance, care and follow-up of technologically dependent infants, and discharge planning. Numerous interventions and care in the neonatal intensive care unit (NICU) fall under the umbrella of health promotion, an aspect of primary care. In addition, NNPs must also be able to recognize, diagnose, and manage myriad common pediatric illnesses. There is a paucity of data to evaluate how NNP programs are meeting the National Association of Neonatal Nurses educational standards on this topic. A REDCap survey was sent to 31 NNP program directors, with a 100% response rate. All programs provide content addressing primary care management in their curriculum. National recognition of the primary care role, in addition to the acute care role that NNPs practice, should increase opportunities for clinical placement sites, employment opportunities, and grant funding. This article aims to demonstrate both the educational preparation and the delivery of primary care that NNPs provide in the NICU and other areas of practice.