bluuebunny/crossref_metadata_2025 huggingface dataset:
Parametric Study of Umbilical Cable and Mooring Line Dynamics With Nonlinear Wave Propagation in Varying Sea Conditions
Authors: Kim Bruce , Adami Nasim , Chen Ming , C. Yim Solomon
Published: September 2023

Majority of the wave energy converters (WEC), especially buoyancy-based point absorbers, are designed to operate in high sea states maximizing energy extraction. Most WEC simulation tools use linear wave theory to analyze the wave field, which could lose accuracy under high sea state conditions. A parametric study is conducted to investigate the effects of the nonlinear wave propagation modeling on WEC responses. The nonlinear Schrödinger (NLS) equation was implemented to develop a nonlinear propagation model. The NLS-based model captures cubic nonlinear phenomena such as extreme sea conditions caused by modulation in wave envelope, which is a critical factor in the survivability of WEC systems. Also, to improve response analysis, mooring/cable system dynamics were represented with a bending stiffness module (MDB). This study was completed using a Reference Model 3 (RM3) WEC system in the National Renewable Energy Laboratory’s (NREL) Wave Energy Converter Simulator (WEC-Sim) in MATLAB. New modules have been built as open-source code to be used in conjunction with the latter, giving more modeling options to the end user and help developing more realistic assessments of a WEC or other floating system in their chosen sea state and location. The model was first subjected to an arbitrary regular wave to prove the interoperability of the two modules and measure initial effectiveness. The presented analysis highlights the differences in the response of the RM3’s system from existing models based on linear wave theory that do not include NLS and MDB in their calculations.
UUV Target Tracking Method Based on High Order CGHF Algorithm
Authors: Zhang Kai , Wang Hongjian , Huang Weiquan , Huang Shihao
Published: September 2023

The delay in the signal detected by sonar due to the limited speed of sound, in unmanned underwater vehicle (UUV) bearing-only target tracking with signal propagation delay, Cubature Gauss-Helmert Filter (CGHF) is often used for target tracking. CGHF uses the third-order Spherical-Radial Cubature Rule (SRCR) to calculate the Gaussian weight integral. Because underwater target tracking is a highly nonlinear system, third-order SRCR has only third-order Taylor expansion term accuracy, the tracking error of CGHF algorithm is large. Aiming at the problem that third-order SRCR has only third-order Taylor expansion term accuracy, a CGHF algorithm based on high-order SRCR is proposed in this paper. In this paper, the state model of Gauss-Helmert model (GHM) is established, the state of the model includes the signal transmission time. The measurement model of underwater target tracking is also given. Based on the GHM model, a new high order CGHF (HOCGHF) is derived by using higher order cubature points. In this paper, a method of evaluating the tracking accuracy of underwater targets and setting the initial filter value is given. Two kinds of underwater target tracking scenarios with different nonlinear degrees are established. The simulation results show that HOCGHF algorithm can effectively track the target in two different underwater target tracking scenarios, and has higher tracking accuracy than the existing methods.
Shape Optimization Design of a Heaving Buoy of Wave Energy Converter Under Bimodal Spectral Waves Near Islands and Reefs
Authors: Huang Shuo , Liu Wei-qi , Wang Kai
Published: September 2023

Wave Energy Converters (WECs) have been developed to advance marine energy technologies towards commercialization. The choice of geometrical shape for WECs is of great importance for increasing energy capture. The characteristics of wave spectrum will be provided with bimodal characteristics when waves propagate from deep water area to the area near the islands and reefs. This variation of the wave spectrum must be considered for the optimization of the WECs placed near islands and reefs. Nevertheless, no standard and consistent method has been established for this purpose yet. The novelty of the present study lies in optimizing the shape of a WEC for maximizing its mean annual absorbed power under bimodal spectral waves when using a flexible geometry definition, such as FFD method. The optimization object is based on a heaving buoy that considers a linear PTO system. The objective of the optimization is to maximize the mean annual absorbed power. The optimization process is proposed by using NSGA-II. A numerical analysis framework based on potential flow theory is presented for determining the mean annual absorbed power under bimodal spectral waves. The results obtained using this method significantly improve the computational efficiency compared to those using CFD method. Thus, this paper provides a guidance for the design of the optimization of the heaving buoy under bimodal spectral waves.
Tibiofemoral Load Magnitude and Distribution During Load Carriage
Authors: Jones Blake W. , Willson John D. , DeVita Paul , Wedge Ryan D.
Published: September 2023

Chronic exposure to high tibiofemoral joint (TFJ) contact forces can be detrimental to knee joint health. Load carriage increases TFJ contact forces, but it is unclear whether medial and lateral tibiofemoral compartments respond similarly to incremental load carriage. The purpose of our study was to compare TFJ contact forces when walking with 15% and 30% added body weight. Young healthy adults (n = 24) walked for 5 minutes with no load, 15% load, and 30% load on an instrumented treadmill. Total, medial, and lateral TFJ contact peak forces and impulses were calculated via an inverse dynamics informed musculoskeletal model. Results of 1-way repeated measures analyses of variance (α = .05) demonstrated total, medial, and lateral TFJ first peak contact forces and impulses increased significantly with increasing load. Orthogonal polynomial trends demonstrated that the 30% loading condition led to a curvilinear increase in total and lateral TFJ impulses, whereas medial first peak TFJ contact forces and impulses responded linearly to increasing load. The total and lateral compartment impulse increased disproportionally with load carriage, while the medial did not. The medial and lateral compartments responded differently to increasing load during walking, warranting further investigation because it may relate to risk of osteoarthritis.
Brain-machine interface learning is facilitated by specific patterning of distributed cortical feedback
Authors: Abbasi Aamir , Lassagne Henri , Estebanez Luc , Goueytes Dorian , Shulz Daniel E. , Ego-Stengel Valerie
Published: September 2023

Neuroprosthetics offer great hope for motor-impaired patients. One obstacle is that fine motor control requires near-instantaneous, rich somatosensory feedback. Such distributed feedback may be recreated in a brain-machine interface using distributed artificial stimulation across the cortical surface. Here, we hypothesized that neuronal stimulation must be contiguous in its spatiotemporal dynamics to be efficiently integrated by sensorimotor circuits. Using a closed-loop brain-machine interface, we trained head-fixed mice to control a virtual cursor by modulating the activity of motor cortex neurons. We provided artificial feedback in real time with distributed optogenetic stimulation patterns in the primary somatosensory cortex. Mice developed a specific motor strategy and succeeded to learn the task only when the optogenetic feedback pattern was spatially and temporally contiguous while it moved across the topography of the somatosensory cortex. These results reveal spatiotemporal properties of the sensorimotor cortical integration that set constraints on the design of neuroprosthetics.
Intranasal mRNA-LNP vaccination protects hamsters from SARS-CoV-2 infection
Authors: Baldeon Vaca Gabriela , Meyer Michelle , Cadete Ana , Hsiao Chiaowen Joyce , Golding Anne , Jeon Albert , Jacquinet Eric , Azcue Emily , Guan Chenxia Monica , Sanchez-Felix Xavier , Pietzsch Colette A. , Mire Chad E. , Hyde Matthew A. , Comeaux Margaret E. , Williams Julie M. , Sung Jean C. , Carfi Andrea , Edwards Darin K. , Bukreyev Alexander , Bahl Kapil
Published: September 2023

Intranasal vaccination represents a promising approach for preventing disease caused by respiratory pathogens by eliciting a mucosal immune response in the respiratory tract that may act as an early barrier to infection and transmission. This study investigated immunogenicity and protective efficacy of intranasally administered messenger RNA (mRNA)–lipid nanoparticle (LNP) encapsulated vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Syrian golden hamsters. Intranasal mRNA-LNP vaccination systemically induced spike-specific binding [immunoglobulin G (IgG) and IgA] and neutralizing antibodies. Intranasally vaccinated hamsters also had decreased viral loads in the respiratory tract, reduced lung pathology, and prevented weight loss after SARS-CoV-2 challenge. Together, this study demonstrates successful immunogenicity and protection against respiratory viral infection by an intranasally administered mRNA-LNP vaccine.
Noise-resistant phase imaging with intensity correlation
Authors: Szuniewicz Jerzy , Kurdziałek Stanisław , Kundu Sanjukta , Zwolinski Wojciech , Chrapkiewicz Radosław , Lahiri Mayukh , Lapkiewicz Radek
Published: September 2023

Interferometric methods form the basis of highly sensitive measurement techniques from astronomy to bioimaging. Interferometry typically requires high stability between the measured and reference beams. The presence of rapid phase fluctuations washes out interference fringes, making phase profile recovery impossible. This challenge can be addressed by shortening the measurement time. However, such an approach reduces photon-counting rates, precluding applications in low-intensity imaging. We introduce a phase imaging technique which is immune to time-dependent phase fluctuations. Our technique, relying on intensity correlation instead of direct intensity measurements, allows one to obtain high interference visibility for arbitrarily long acquisition times. We prove the optimality of our method using the Cramér-Rao bound in the extreme case when no more than two photons are detected within the time window of phase stability. Our technique will broaden prospects in phase measurements, including emerging applications such as in infrared and x-ray imaging and quantum and matter-wave interferometry.
A large-scale observational study of the causal effects of a behavioral health nudge
Authors: Nazaret Achille , Sapiro Guillermo
Published: September 2023

Nudges are interventions promoting healthy behavior without forbidding options or substantial incentives; the Apple Watch, for example, encourages users to stand by delivering a notification if they have been sitting for the first 50 minutes of an hour. On the basis of 76 billion minutes of observational standing data from 160,000 subjects in the public Apple Heart and Movement Study, we estimate the causal effect of this notification using a regression discontinuity design for time series data with time-varying treatment. We show that the nudge increases the probability of standing by up to 43.9% and remains effective with time. The nudge’s effectiveness increases with age and is independent of gender. Closing Apple Watch Activity Rings, a visualization of participants’ daily progress in Move, Exercise, and Stand, further increases the nudge’s impact. This work demonstrates the effectiveness of behavioral health interventions and introduces tools for investigating their causal effect from large-scale observations.
Deep learning enabled fast 3D brain MRI at 0.055 tesla
Authors: Man Christopher , Lau Vick , Su Shi , Zhao Yujiao , Xiao Linfang , Ding Ye , Leung Gilberto K. K. , Leong Alex T. L. , Wu Ed X.
Published: September 2023

In recent years, there has been an intensive development of portable ultralow-field magnetic resonance imaging (MRI) for low-cost, shielding-free, and point-of-care applications. However, its quality is poor and scan time is long. We propose a fast acquisition and deep learning reconstruction framework to accelerate brain MRI at 0.055 tesla. The acquisition consists of a single average three-dimensional (3D) encoding with 2D partial Fourier sampling, reducing the scan time of T1- and T2-weighted imaging protocols to 2.5 and 3.2 minutes, respectively. The 3D deep learning leverages the homogeneous brain anatomy available in high-field human brain data to enhance image quality, reduce artifacts and noise, and improve spatial resolution to synthetic 1.5-mm isotropic resolution. Our method successfully overcomes low-signal barrier, reconstructing fine anatomical structures that are reproducible within subjects and consistent across two protocols. It enables fast and quality whole-brain MRI at 0.055 tesla, with potential for widespread biomedical applications.
Crystal structure and solution state of the C-terminal head region of the narmovirus receptor binding protein
Authors: Stelfox Alice J. , Oguntuyo Kasopefoluwa Y. , Rissanen Ilona , Harlos Karl , Rambo Robert , Lee Benhur , Bowden Thomas A.
Published: September 2023

Increased viral surveillance has led to the isolation and identification of numerous uncharacterized paramyxoviruses, rapidly expanding our understanding of paramyxoviral diversity beyond the bounds of known genera. Despite this diversity, a key feature that unites paramyxoviruses is the presence of a receptor-binding protein (RBP), which facilitates host-cell attachment and plays a fundamental role in determining host range. Here, we study the RBP presented on the surface of rodent-borne paramyxoviruses Mossman and Nariva (MosV and NarV, respectively), viruses that constitute founding members of the recently defined
Narmovirus
genus within the
Paramyxoviridae
family. Crystallographic analysis of the C-terminal head region of the dimeric MosV and NarV RBPs demonstrates that while these glycoproteins retain the canonical six-bladed β-propeller fold found in other paramyxoviral RBPs, they lack the structural motifs associated with established paramyxovirus host-cell receptor entry pathways. Consistent with MosV-RBP and NarV-RBP undergoing a distinct entry pathway from other characterized paramyxoviruses, structure-based phylogenetic analysis demonstrates that these six-bladed β-propeller head domains form a singular structural class that is distinct from other paramyxoviral RBPs. Additionally, using an integrated crystallographic and small-angle X-ray scattering analysis, we confirm that MosV-RBP and NarV-RBP form homodimeric arrangements that are distinct from those adopted by other paramyxovirus RBPs. Altogether, this investigation provides a molecular-level blueprint of the narmovirus RBP that broadens our understanding of the structural space and functional diversity available to paramyxovirus RBPs.

IMPORTANCE

Genetically diverse paramyxoviruses are united in their presentation of a receptor-binding protein (RBP), which works in concert with the fusion protein to facilitate host-cell entry. The C-terminal head region of the paramyxoviral RBP, a primary determinant of host-cell tropism and inter-species transmission potential, forms structurally distinct classes dependent upon protein and glycan receptor specificity. Here, we reveal the architecture of the C-terminal head region of the RBPs from Nariva virus (NarV) and Mossman virus (MosV), two archetypal rodent-borne paramyxoviruses within the recently established genus
Narmovirus
, family
Paramyxoviridae
. Our analysis reveals that while narmoviruses retain the general architectural features associated with paramyxoviral RBPs, namely, a six-bladed β-propeller fold, they lack the structural motifs associated with known receptor-mediated host-cell entry pathways. This investigation indicates that the RBPs of narmoviruses exhibit pathobiological features that are distinct from those of other paramyxoviruses.
Suggested role of NosZ in preventing N
2
O inhibition of dissimilatory nitrite reduction to ammonium
Authors: Yoon Sojung , Heo Hokwan , Han Heejoo , Song Dong-Uk , Bakken Lars R. , Frostegård Åsa , Yoon Sukhwan
Published: September 2023

Climate change and nutrient pollution are among the most urgent environmental issues. Enhancing the abundance and/or the activity of beneficial organisms is an attractive strategy to counteract these problems. Dissimilatory nitrate reduction to ammonium (DNRA), which theoretically improves nitrogen retention in soils, has been suggested as a microbial process that may be harnessed, especially since many DNRA-catalyzing organisms have been found to possess
nosZ
genes and the ability to respire N
2
O. However, the selective advantage that may favor these
nosZ
-harboring DNRA-catalyzing organisms is not well understood. Here, the effect of N
2
O on Nrf-mediated DNRA was examined in a soil isolate,
Bacillus
sp. DNRA2, possessing both
nrfA
and
nosZ
genes. The DNRA metabolism of this bacterium was observed in the presence of C
2
H
2,
a NosZ inhibitor, with or without N
2
O, and the results were compared with C
2
H
2
-free controls. Cultures were also exposed to repeated oxic-anoxic transitions in the sustained presence of N
2
O. The NO
2
−
-to-NH
4
+
reduction following oxic-to-anoxic transition was significantly delayed in NosZ-inhibited C
2
H
2
-amended cultures, and the inhibition was more pronounced with repeated oxic-anoxic transitions. The possibility of C
2
H
2
involvement was dismissed since the cultures continuously flushed with C
2
H
2
/N
2
mixed gas after initial oxic incubation did not exhibit a similar delay in DNRA progression as that observed in the culture flushed with N
2
O-containing gas. The findings suggest a possibility that the oft-observed
nosZ
presence in DNRA-catalyzing microorganisms secures an early transcription of their DNRA genes by scavenging N
2
O, thus enhancing their capacity to compete with denitrifiers at oxic-anoxic interfaces.

IMPORTANCE

Dissimilatory nitrate/nitrite reduction to ammonium (DNRA) is a microbial energy-conserving process that reduces NO
3
−
and/or NO
2
−
to NH
4
+
. Interestingly, DNRA-catalyzing microorganisms possessing
nrfA
genes are occasionally found harboring
nosZ
genes encoding nitrous oxide reductases, i.e., the only group of enzymes capable of removing the potent greenhouse gas N
2
O. Here, through a series of physiological experiments examining DNRA metabolism in one of such microorganisms,
Bacillus
sp. DNRA2, we have discovered that N
2
O may delay the transition to DNRA upon an oxic-to-anoxic transition, unless timely removed by the nitrous oxide reductases. These observations suggest a novel explanation as to why some
nrfA
-possessing microorganisms have retained
nosZ
genes: to remove N
2
O that may otherwise interfere with the transition from O
2
respiration to DNRA.
Human GBP1 facilitates the rupture of the
Legionella-
containing vacuole and inflammasome activation
Authors: Bass Antonia R. , Egan Marisa S. , Alexander-Floyd Jasmine , Lopes Fischer Natasha , Doerner Jessica , Shin Sunny
Published: September 2023

The inflammasome is essential for host defense against intracellular bacterial pathogens, including
Legionella pneumophila
, the causative agent of the severe pneumonia Legionnaires’ disease. Inflammasomes recruit and activate caspases, which promote IL-1 family cytokine release and pyroptosis to restrict infection. In mice, interferon (IFN) signaling promotes inflammasome responses against
L. pneumophila
and other bacteria
,
in part, through inducing a family of IFN-inducible GTPases known as guanylate-binding proteins (GBPs). Within murine macrophages, IFN promotes the rupture of the
L. pneumophila
-containing vacuole (LCV), while GBPs are dispensable for vacuole rupture. Instead, GBPs facilitate the lysis of cytosol-exposed
L. pneumophila
. In contrast, the functions of IFN-γ and GBPs in human inflammasome responses to
L. pneumophila
are poorly understood. Here, we show that IFN-γ enhances caspase-1- and caspase-4-dependent inflammasome responses to
L. pneumophila
in human macrophages. We find that human GBP1 is required for these IFN-γ-driven inflammasome responses. Furthermore, we find that GBP1 co-localizes with
L. pneumophila
and/or LCVs in a type IV secretion system (T4SS)-dependent manner and facilitates damage to the LCV, resulting in increased bacterial access to the host cell cytosol. Our findings reveal species- and pathogen-specific differences in how GBPs function during infection.

Importance

Inflammasomes are essential for host defense against intracellular bacterial pathogens like
Legionella
, as they activate caspases, which promote cytokine release and cell death to control infection. In mice, interferon (IFN) signaling promotes inflammasome responses against bacteria by inducing a family of IFN-inducible GTPases known as guanylate-binding proteins (GBPs). Within murine macrophages, IFN promotes the rupture of the
Legionella
-containing vacuole (LCV), while GBPs are dispensable for this process. Instead, GBPs facilitate the lysis of cytosol-exposed
Legionella
. In contrast, the functions of IFN and GBPs in human inflammasome responses to
Legionella
are poorly understood. We show that IFN-γ enhances inflammasome responses to
Legionella
in human macrophages. Human GBP1 is required for these IFN-γ-driven inflammasome responses. Furthermore, GBP1 co-localizes with
Legionella
and/or LCVs in a type IV secretion system (T4SS)-dependent manner and promotes damage to the LCV, which leads to increased exposure of the bacteria to the host cell cytosol. Thus, our findings reveal species- and pathogen-specific differences in how GBPs function to promote inflammasome responses.
Conformational variability of cyanobacterial ChlI, the AAA+ motor of magnesium chelatase involved in chlorophyll biosynthesis
Authors: Shvarev Dmitry , Scholz Alischa Ira , Moeller Arne
Published: September 2023

Magnesium chelatase is a conserved enzyme complex responsible for the first committed step of chlorophyll biosynthesis in photosynthetic organisms, which is the addition of magnesium to the chlorophyll precursor, protoporphyrin IX. The complex is composed of the catalytic subunit ChlH, the bridging subunit ChlD, and the subunit ChlI, which serves as the motor that drives the entire complex. Although the enzyme is well-characterized functionally, high-resolution structures are available only for individual subunits. Hence, the full assembly and molecular mechanism of the enzyme complex remain unknown. Here, we used cryogenic electron microscopy, supported by biochemical analysis and mass photometry, to determine the structures of the ChlI motor subunit of magnesium chelatase under turnover conditions in the presence of ATP. Our data reveal the molecular details of ChlI oligomerization and conformational dynamics upon ATP binding and hydrolysis. These findings provide new insights into the mechanistic function of ChlI and its implications for the entire magnesium chelatase complex machinery.

Importance

Photosynthesis is an essential life process that relies on chlorophyll. In photosynthetic organisms, chlorophyll synthesis involves multiple steps and depends on magnesium chelatase. This enzyme complex is responsible for inserting magnesium into the chlorophyll precursor, but the molecular mechanism of this process is not fully understood. By using cryogenic electron microscopy and conducting functional analyses, we have discovered that the motor subunit ChlI of magnesium chelatase undergoes conformational changes in the presence of ATP. Our findings offer new insights into how energy is transferred from ChlI to the other components of magnesium chelatase. This information significantly contributes to our understanding of the initial step in chlorophyll biosynthesis and lays the foundation for future studies on the entire process of chlorophyll production.
Ultrastructure and 3D reconstruction of a diplonemid protist (Diplonemea) and its novel membranous organelle
Authors: Tashyreva Daria , Týč Jiří , Horák Aleš , Lukeš Julius
Published: September 2023

Although diplonemid protists (Diplonemea, Euglenozoa) are among the most species-rich microeukaryotes in the ocean, many ultrastructural features of this lineage remain to be clarified. Using serial block-face scanning and transmission electron microscopy, we provide the whole-cell three-dimensional model of a previously undescribed diplonemid
Lacrimia vacuolata
sp. nov. For the first time, we were able to reconstruct a diplonemid cell in detail, including all its organelles and the flagellar and feeding apparatuses. By analyzing various stages of the cell cycle, we provide the first description of a diplonemid cell division, which is characterized by the disassembly of flagellar axonemes and the feeding apparatus and their further construction in the daughter cells. Moreover, we have identified a novel, ultrastructurally complex organelle, herein named the colv (
C
enter for
O
rganization of
L
ayered
V
esicles). We suggest that the colv is involved in food processing and membrane trafficking, and describe its close association with other components of the cellular digestive system.

IMPORTANCE

The knowledge of cell biology of a eukaryotic group is essential for correct interpretation of ecological and molecular data. Although diplonemid protists are one of the most species-rich lineages of marine eukaryotes, only very fragmentary information is available about the cellular architecture of this taxonomically diverse group. Here, a large serial block-face scanning electron microscopy data set complemented with light and fluorescence microscopy allowed the first detailed three-dimensional reconstruction of a diplonemid species. We describe numerous previously unknown peculiarities of the cellular architecture and cell division characteristic for diplonemid flagellates, and illustrate the obtained results with multiple three-dimensional models, comprehensible for non-specialists in protist ultrastructure.
Draft genome sequence of
Acinetobacter
sp. AYS6, a potential plant growth-promoting endophyte
Authors: Fadiji Ayomide Emmanuel , Ayangbenro Ayansina Segun , Akanmu Akinlolu Olalekan , Babalola Olubukola Oluranti
Published: September 2023

Here, we report the draft genome sequence of
Acinetobacter sp
. AYS6, an endophyte isolated from the roots of maize plant in Mafikeng, South Africa. The genome was 7,072,605 bp and exhibited a GC content of 45.6% and 3,654 genes with 3,539 coding sequences, 64 rRNA, 60 tRNAs, and 2 CRISPR.
The resistomes of rural and urban pigs and poultry in Ghana
Authors: Jensen Emilie Egholm Bruun , Sedor Victoria , Eshun Emmanuel , Njage Patrick , Otani Saria , Aarestrup Frank M.
Published: September 2023

There is limited knowledge on the bacteriome and resistome in livestock in Africa and the potential influence of the animal husbandry practices and scale has also been scantly explored. We quantified and characterized the antimicrobial resistance gene (ARG) pools (resistomes) and bacteriome in 30 pigs and 60 poultry samples (free-range: rural and urban, and industrialized) across Ghana using Resfinder and Silva databases and compared them to similar data from pigs and poultry from nine European countries. The pig and poultry were very different in ARG and bacterial abundance and composition. The bacterial communities in the Ghanaian samples also differed substantially from the European samples, especially driven by a much higher abundance of
Subdoligranulum
in both animals. We found lower ARG loads in Ghanaian pigs compared to European counterparts. Among poultry, urban free-range samples exhibited lower ARG abundances compared to the lowest European levels, while rural free-range samples were comparable to the European average, and industrialized samples showed higher ARG abundances. Despite major differences in abundance, the resistome composition of Ghanaian urban, rural, and industrialized poultry samples was similar. Contrasts with European samples were mainly driven by increased abundances of different tetracycline resistance genes in Ghanaian samples, and increased abundances of ARGs encoding resistance to macrolides, beta-lactams, and trimethoprim in Europe. Among pig samples, the main differences were caused by ARGs encoding resistance to nitroimidazoles, beta-lactams, and macrolides in European samples. This study is, to the best of our knowledge, the first report on the resistome measured using metagenomics in livestock from Sub-Saharan Africa.

IMPORTANCE

To the best of our knowledge, this is the first report on the resistomes that are measured using metagenomics in livestock from Sub-Saharan Africa. We find notable differences in the microbiomes between both pigs and poultry, and those also varied markedly compared to similar samples from Europe. However, for both animal species, the same bacterial taxa drove such differences. In pigs and urban free-range poultry, we find a very low abundance of antimicrobial resistance genes (ARGs), whereas rural free-range poultry displayed similarity to the European average, and industrialized poultry exhibited higher levels. These findings show how different African livestock bacterial communities and resistomes are from their European counterparts. They also underscore the importance of continued surveillance and investigation into antimicrobial resistance across diverse ecosystems, contributing significantly to global efforts toward combating the threat of antibiotic resistance.
Tonsils are major sites of persistence of SARS-CoV-2 in children
Authors: Lima Thais Melquiades de , Martins Ronaldo Bragança , Miura Carolina Sponchiado , Souza Maria Vitória Oliveira , Cassiano Murilo Henrique Anzolini , Rodrigues Tamara Silva , Veras Flávio Protásio , Sousa Josane de Freitas , Gomes Rogério , Almeida Glaucia Maria de , Melo Stella Rezende , Silva Gabriela Condé da , Dias Matheus , Capato Carlos Fabiano , Silva Maria Lúcia , Luiz Veridiana Ester Dias de Barros , Carenzi Lucas Rodrigues , Zamboni Dario Simões , Jorge Daniel Macedo de Melo , Cunha Fernando de Queiroz , Tamashiro Edwin , Anselmo-Lima Wilma Terezinha , Valera Fabiana Cardoso Pereira , Arruda Eurico
Published: September 2023

In the present study, we show that SARS-CoV-2 can infect palatine tonsils, adenoids, and secretions in children without symptoms of COVID-19, with no history of recent upper airway infection. We studied 48 children undergoing tonsillectomy due to snoring/OSA or recurrent tonsillitis between October 2020 and September 2021. Nasal cytobrushes, nasal washes, and tonsillar tissue fragments obtained at surgery were tested by RT-qPCR, immunohistochemistry (IHC), flow cytometry, and neutralization assay. We detected the presence of SARS-CoV-2 in at least one specimen tested in 27% of patients. IHC revealed the presence of the viral nucleoprotein in epithelial surface and in lymphoid cells in both extrafollicular and follicular regions, in adenoids and palatine tonsils. Also, IHC for the SARS-CoV-2 non-structural protein NSP-16 indicated the presence of viral replication in 53.8% of the SARS-CoV-2-infected tissues. Flow cytometry showed that CD20
+
B lymphocytes were the most infected phenotypes, followed by CD4+ lymphocytes and CD123 dendritic cells, CD8+ T lymphocytes, and CD14+ macrophages. Additionally, IF indicated that infected tonsillar tissues had increased expression of ACE2 and TMPRSS2. NGS sequencing demonstrated the presence of different SARS-CoV-2 variants in tonsils from different tissues. SARS-CoV-2 antigen detection was not restricted to tonsils but was also detected in nasal cells from the olfactory region. Palatine tonsils and adenoids are sites of prolonged RNA presence by SARS-CoV-2 in children, even without COVID-19 symptoms.

IMPORTANCE

This study shows that SRS-CoV-2 of different lineages can infect tonsils and adenoids in one quarter of children undergoing tonsillectomy. These findings bring advancement to the area of SARS-CoV-2 pathogenesis, by showing that tonsils may be sites of prolonged infection, even without evidence of recent COVID-19 symptoms. SARS-CoV-2 infection of B and T lymphocytes, macrophages, and dendritic cells may interfere with the mounting of immune responses in these secondary lymphoid organs. Moreover, the shedding of SARS-CoV-2 RNA in respiratory secretions from silently infected children raises concern about possible diagnostic confusion in the presence of symptoms of acute respiratory infections caused by other etiologies.
Monocentric observational cohort study to investigate the transmission of third-generation cephalosporin-resistant Enterobacterales in a neonatal intensive care unit in Heidelberg, Germany
Authors: Nurjadi Dennis , Eichel Vanessa M. , Pöschl Johannes , Gille Christian , Kranig Simon , Heeg Klaus , Boutin Sébastien
Published: September 2023

Third-generation cephalosporin-resistant Enterobacterales is a major threat for newborns in neonatal intensive care units (NICUs). The route of acquisition in a non-outbreak setting should be investigated to implement adequate infection prevention measures. To identify risk factors for colonization with and to investigate the transmission pattern of third-generation cephalosporin-resistant Enterobacterales in a NICU setting. This monocentric observational cohort study in a tertiary NICU in Heidelberg, Germany, enrolled all hospitalized neonates screened for cephalosporin-resistant Enterobacterales. Data were collected from 1 January 2018 to 31 December 2021. Weekly screening by rectal swabs for colonization with third-generation cephalosporin-resistant Enterobacterales was performed for all newborns until discharge. Whole-genome sequencing was performed for molecular characterization and transmission analysis. In total, 1,287 newborns were enrolled. The median length of stay was 20 (range 1–250) days. Eighy-eight infants (6.8%) were colonized with third-generation cephalosporin-resistant Enterobacterales. Low birth weight [<1500 g (adjusted odds ratio, 5.1; 95% CI 2.2–11.5;
P
< 0.001)] and longer hospitalization [per 30 days (adjusted odds ratio, 1.7; 95% CI 1.5–2.0;
P
< 0.001)] were associated with colonization or infection with drug-resistant Enterobacterales in a multivariate analysis.
Enterobacter cloacae
complex was the most prevalent third-generation cephalosporin-resistant Enterobacterales detected, 64.8% (59 of 91). Whole-genome sequencing, performed for the available 85 of 91 isolates, indicated 12 transmission clusters involving 37 patients. This cohort study suggests that transmissions of third-generation cephalosporin-resistant Enterobacterales in newborns occur frequently in a non-outbreak NICU setting, highlighting the importance of surveillance and preventive measures in this vulnerable patient group.

IMPORTANCE

Preterm newborns are prone to infections. Therefore, infection prevention should be prioritized in this vulnerable patient group. However, outbreaks involving drug-resistant bacteria, such as third-generation resistant Enterobacterales, are often reported. Our study aims to investigate transmission and risk factors for acquiring third-generation cephalosporin-resistant Enterobacterales in a non-outbreak NICU setting. Our data indicated that premature birth and low birth weight are significant risk factors for colonization/infection with third-generation cephalosporin-resistant Enterobacterales. Furthermore, we could identify putative transmission clusters by whole-genome sequencing, highlighting the importance of preemptive measures to prevent infections in this patient collective.
Delayed approach to postdural puncture headache
Authors: Guo Haiyan , Villaluz Joseph
Published: September 2023

A postpartum female in her mid-20s presented with atypical symptoms of postdural puncture headache. However, on initial presentation, the patient reported no headache. Primary symptoms of acute, severe interscapular pain and upper extremity radiculopathy at the time of epidural placement were observed. The absence of a positional headache and the severity of pain at presentation prompted MRI analysis to establish a clinical diagnosis.

MRI findings revealed a significant cerebrospinal fluid (CSF) leak causing a mass effect on the cervicothoracic spinal cord and severe stenosis at the cauda equina. An epidural blood patch (EBP) was considered; however, it was postulated that the narrow epidural space would not be sufficient to accommodate the volume associated with an EBP. She was managed conservatively until subsequent imaging revealed CSF resorption. She received an epidural blood patch on day 7. Thereafter, her symptoms improved, allowing her to nurse her infant and be discharged home.
DualM. kansasiiinfection in one household: a reconsideration of our understanding of transmission routes
Authors: Moody Samuel John , Johnson Leann , Moody Thomas
Published: September 2023

Mycobacterium kansasiiis one of the the most common non-tuberculous mycobacteria responsible for opportunistic human infection. UnlikeM. tuberculosis, transmission remains poorly understood; spread is assumed to be from a shared geographical source, such as domestic plumbing, and human-to-human transmission is generally not considered by clinicians when evaluating patients and their environments. We describeM. kansasiiinfection in a husband and wife in the same household and in the same period, suggesting, in these cases, that transmission occurred directly from one patient to the other. This possibility of human-to-human transmission may inform a clinician’s scrutiny of risks to household contacts in cases ofM. kansasiiinfection.
Angioedema without urticaria after recent initiation of celecoxib
Authors: Jasti Vivek Vardhan , Anderson Jay , Abdujelil Ifa
Published: September 2023

Angioedema is potentially life-threating swelling of integument and mucosa that has multiple potential aetiologies with varying mechanisms. Drug-induced angioedema is often easily correlated with the offending agent and can be prevented with discontinuation of the medication. Many medications have now been implicated in drug-induced angioedema but the two most common are ACE inhibitors and non-steroidal anti-inflammatory drugs (NSAIDs). This case highlights severe angioedema secondary to celecoxib and reviews varying aetiologies of angioedema and NSAID hypersensitivity reactions.
Addressing vaccine hesitancy: experimental evidence from nine high-income countries during the COVID-19 pandemic
Authors: Galasso Vincenzo , Pons Vincent , Profeta Paola , McKee Martin , Stuckler David , Becher Michael , Brouard Sylvain , Foucault Martial
Published: September 2023

We study the impact of public health messages on intentions to vaccinate and vaccination uptakes, especially among hesitant groups. We performed an experiment comparing the effects of egoistic and altruistic messages on COVID-19 vaccine intentions and behaviour. We administered different messages at random in a survey of 6379 adults in December 2020, following up with participants in the nationally representative survey Citizens’ Attitudes Under COVID-19 Project covering nine high-income countries (Australia, Austria, France, Germany, Italy, New Zealand, Sweden, the UK and the USA). Four alternative interventions were tested, based on narratives of (1) self-protection, (2) protecting others, (3) reducing health risks and (4) economic protection. We measure vaccination intentions in the December 2020 survey and elicit actual vaccination behaviour by respondents in the June/July 2021 survey. Messages conveying self-protection had no effect on vaccine intentions but altruistic messages, emphasising protecting other individuals (0.022, 95% CI −0.004 to 0.048), population health (0.030, 95% CI 0.003 to 0.056) and the economy (0.038, 95% CI 0.013 to 0.064) had substantially stronger effects. These effects were stronger in countries experiencing high COVID-19 mortality (Austria, France, Italy, Sweden, the UK and the USA), where health risks may have been more salient, but weaker and, in several cases, not significant where mortality was low (Australia, Germany and New Zealand). On follow-up at 6 months, these brief communication interventions corresponded to substantially higher vaccination uptake. Our experiments found that commonly employed narratives around self-protection had no effect. However, altruistic messages about protecting individuals, population health and the economy had substantially positive and enduring effects on increasing vaccination intentions. Our results can help structure communication campaigns during pandemics and are likely to generalise to other vaccine-preventable epidemics.
Antenatal corticosteroids in specific groups at risk of preterm birth: a systematic review
Authors: Saito Kana , Nishimura Etsuko , Ota Erika , Namba Fumihiko , Swa Toshiyuki , Ramson Jenny , Lavin Tina , Cao Jenny , Vogel Joshua Peter
Published: September 2023

Objective

This study aimed to synthesise available evidence on the efficacy of antenatal corticosteroid (ACS) therapy among women at risk of imminent preterm birth with pregestational/gestational diabetes, chorioamnionitis or fetal growth restriction (FGR), or planned caesarean section (CS) in the late preterm period.

Methods

A systematic search of MEDLINE, EMBASE, CINAHL, Cochrane Library, Web of Science and Global Index Medicus was conducted for all comparative randomised or non-randomised interventional studies in the four subpopulations on 6 June 2021. Risk of Bias Assessment tool for Non-randomised Studies and the Cochrane Risk of Bias tool were used to assess the risk of bias. Grading of Recommendations Assessment, Development and Evaluations tool assessed the certainty of evidence.

Results

Thirty-two studies involving 5018 pregnant women and 10 819 neonates were included. Data on women with diabetes were limited, and evidence on women undergoing planned CS was inconclusive. ACS use was associated with possibly reduced odds of neonatal death (pooled OR: 0.51; 95% CI: 0.31 to 0.85, low certainty), intraventricular haemorrhage (pooled OR: 0.41; 95% CI: 0.23 to 0.72, low certainty) and respiratory distress syndrome (pooled OR: 0.59; 95% CI: 0.45 to 0.77, low certainty) in women with chorioamnionitis. Among women with FGR, the rates of surfactant use (pooled OR: 0.38; 95% CI: 0.23 to 0.62, moderate certainty), mechanical ventilation (pooled OR: 0.42; 95% CI: 0.26 to 0.66, moderate certainty) and oxygen therapy (pooled OR: 0.48; 95% CI: 0.30 to 0.77, moderate certainty) were probably reduced; however, the rate of hypoglycaemia probably increased (pooled OR: 2.06; 95% CI: 1.27 to 3.32, moderate certainty).

Conclusions

There is a paucity of evidence on ACS for women who have diabetes. ACS therapy may have benefits in women with chorioamnionitis and is probably beneficial in FGR. There is limited direct trial evidence on ACS efficacy in women undergoing planned CS in the late preterm period, though the totality of evidence suggests it is probably beneficial.

PROSPERO registration number

CRD42021267816.
Measurement and outcomes of co-production in health and social care: a systematic review of empirical studies
Authors: Nordin Annika , Kjellstrom Sofia , Robert Glenn , Masterson Daniel , Areskoug Josefsson Kristina
Published: September 2023

Background

Co-production is promoted as an effective way of improving the quality of health and social care but the diversity of measures used in individual studies makes their outcomes difficult to interpret.

Objective

The objective is to explore how empirical studies in health and social care have described the outcomes of co-production projects and how those outcomes were measured.

Design and methods

A scoping review forms the basis for this systematic review. Search terms for the concepts (co-produc* OR coproduc* OR co-design* OR codesign*) and contexts (health OR ‘public service* OR “public sector”) were used in: CINAHL with Full Text (EBSCOHost), Cochrane Central Register of Controlled trials (Wiley), MEDLINE (EBSCOHost), PsycINFO (ProQuest), PubMed (legacy) and Scopus (Elsevier). There was no date limit. Papers describing the process, original data and outcomes of co-production were included. Protocols, reviews and theoretical, conceptual and psychometric papers were excluded. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was followed. The Mixed Methods Appraisal Tool underpinned the quality of included papers.

Results

43 empirical studies were included. They were conducted in 12 countries, with the UK representing >50% of all papers. No paper was excluded due to the Mixed Methods Quality Appraisal screening and 60% of included papers were mixed methods studies. The extensive use of self-developed study-specific measures hampered comparisons and cumulative knowledge-building. Overall, the studies reported positive outcomes. Co-production was reported to be positively experienced and provided important learning.

Conclusions

The lack of common approaches to measuring co-production is more problematic than the plurality of measurements itself. Co-production should be measured from three perspectives: outputs of co-production processes, the experiences of participating in co-production processes and outcomes of co-production. Both self-developed study-specific measures and established measures should be used. The maturity of this research field would benefit from the development and use of reporting guidelines.
Association between using a prehospital assessment unit and hospital admission and mortality: a matched cohort study
Authors: Wolthers Signe Amalie , Blomberg Stig Nikolaj Fasmer , Breindahl Niklas , Anjum Sair , Hägi-Pedersen Daniel , Ersbøll Annette , Andersen Lars Bredevang , Christensen Helle Collatz
Published: September 2023

Objectives

This study aimed to compare hospital admission and 30-day mortality between patients assessed by the prehospital assessment unit (PAU) and patients not assessed by the PAU.

Design

This was a matched cohort study.

Setting

This study was conducted between November 2021 and October 2022 in Region Zealand, Denmark.

Participants

989 patients aged >18, assessed by the PAU, were identified, and 9860 patients not assessed by the PAU were selected from the emergency calls using exposure density sampling.

Exposure

Patients assessed by the PAU. The PAU is operated by paramedics with access to point-of-care test facilities. The PAU is an alternative response vehicle without the capability of transporting patients.

Primary and secondary outcome measures

The primary outcome was hospital admission within 48 hours after the initial call. The key secondary outcomes were admission within 7 days, 30-day mortality and admission within 6 hours. Descriptive statistical analyses were conducted, and logistic regression models were used to estimate adjusted OR (aOR) and 95% CI.

Results

Among the PAU assessed, 44.1% were admitted within 48 hours, compared with 72.9% of the non-PAU assessed, p<0.001. The multivariable analysis showed a lower risk of admission within 48 hours and 7 days among the PAU patients, aOR 0.31 (95% CI 0.26 to 0.38) and aOR 0.50 (95% CI 0.38 to 0.64), respectively. The 30-day mortality rate was 3.8% in the PAU-assessed patients vs 5.5% in the non-PAU-assessed patients, p=0.03. In the multivariable analysis, no significant difference was found in mortality aOR 0.99 (95% CI 0.71 to 1.42). No deaths were observed in PAU-assessed patients without subsequent follow-up.

Conclusion

The recently introduced PAU aims for patient-centred emergency care. The PAU-assessed patients had reduced admissions within 48 hours and 7 days after the initial call. Study findings indicate that the PAU is safe since we identified no significant differences in 30-day mortality.

Trial registration number

NCT05654909.